"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:13f9b1f0-2a1b-4147-a051-66ac364f1c11","http://resolver.tudelft.nl/uuid:13f9b1f0-2a1b-4147-a051-66ac364f1c11","Improving mechanical properties and sustainability of high-strength engineered cementitious composites (ECC) using diatomite","Zhu, Xuezhen (Central South University China); Zhang, Minghu (Central South University China); Shi, Jinyan (Central South University China); Weng, Yiwei (The Hong Kong Polytechnic University); Yalçınkaya, Çağlar (Dokuz Eylul University); Šavija, B. (TU Delft Materials and Environment)","","2024","High-strength engineered cementitious composites (ECC) typically require higher cement content, which is negative from the sustainability point of view. To alleviate this problem, herein a low-cost and eco-friendly high-strength ECC (with a compressive strength of over 100 MPa) was developed, and diatomite was used to replace a small amount of cement. An appropriate amount of diatomite was found to improve the compressive strength, tensile strength and first cracking strength of ECC, but at the expense of part of the strain capacity (still all higher than 2.9%). Furthermore, the high pozzolanic activity and specific surface area of diatomite also increased the autogenous shrinkage, but reduced the drying shrinkage of ECC due to its internal curing effect. The incorporation of diatomite improved the pore structure of ECC, consumed more Ca(OH)2, and enhanced the hydration degree of the mixture. In the end, the economic and environmental benefits of diatomite-modified ECC were also evaluated, and the cost, non-renewable energy demand, and global warming potential of ECC with 3% diatomite were reduced compared to plain ECC by 12.9, 15.1, and 13.3%, respectively. The developed high-strength ECC is therefore a low-cost and eco-friendly alternative to the traditional one.","Diatomite; Engineered cementitious composites (ECC); High-strength; Sustainability assessment; Tensile properties","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-07-02","","","Materials and Environment","","",""
"uuid:accfe314-6066-4eb5-ad14-04fad3e0f168","http://resolver.tudelft.nl/uuid:accfe314-6066-4eb5-ad14-04fad3e0f168","The Slow and The Furious? Performance Antipattern Detection in Cyber-Physical Systems","van Dinten, I. (TU Delft Software Engineering); Derakhshanfar, Pouria (JetBrains Research); Panichella, A. (TU Delft Software Engineering); Zaidman, A.E. (TU Delft Software Technology)","","2024","Cyber-Physical Systems (CPSs) have gained traction in recent years. A major non-functional quality of CPS is performance since it affects both usability and security. This critical quality attribute depends on the specialized hardware, simulation engines, and environmental factors that characterize the system under analysis. While a large body of research exists on performance issues in general, studies focusing on performance-related issues for CPSs are scarce. The goal of this paper is to build a taxonomy of performance issues in CPSs. To this aim, we present two empirical studies aimed at categorizing common performance issues (Study I) and helping developers detect them (Study II). In the first study, we examined commit messages and code changes in the history of 14 GitHub-hosted open-source CPS projects to identify commits that report and fix self-admitted performance issues. We manually analyzed 2699 commits, labeled them, and grouped the reported performance issues into antipatterns. We detected instances of three previously reported Software Performance Antipatterns (SPAs) for CPSs. Importantly, we also identified new SPAs for CPSs not described earlier in the literature. Furthermore, most performance issues identified in this study fall into two new antipattern categories: Hard Coded Fine Tuning (399 of 646) and Magical Waiting Number (150 of 646). In the second study, we introduce static analysis techniques for automatically detecting these two new antipatterns; we implemented them in a tool called AP-Spotter. We analyzed 9 open-source CPS projects not utilized to build the SPAs taxonomy to benchmark AP-Spotter. Our results show that AP-Spotter achieves 62.04% precision in detecting the antipatterns","Software performance antipatterns; Cyber-Physical Systems; Antipattern Detection; Software Maintenance; Empirical Software Engineering; Static Analysis","en","journal article","","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:4ee1cced-5077-4c1e-9612-6e0b3cc8fcdf","http://resolver.tudelft.nl/uuid:4ee1cced-5077-4c1e-9612-6e0b3cc8fcdf","Introductory Dynamics: 2D Kinematics and Kinetics of Point Masses and Rigid Bodies","Steeneken, P.G. (TU Delft Dynamics of Micro and Nano Systems)","","2024","Motion is all around us, the universe is full of moving matter and this motion is surprisingly predictable. The field of science and engineering that studies time-dependent motion in the presence of forces is called Dynamics. In this book we will introduce the core concepts in dynamics and provide a comprehensive toolset to predict and analyse planar 2D motion of point masses and rigid bodies. The material includes kinematic analysis, Newton’s laws, Euler’s laws, the equations of motion, work, energy, impulse and momentum. Vector-based methods are discussed for systematically solving essentially any problem in 2D dynamics. The book provides a bachelor level introduction for any science and engineering student that can serve as a basis for more advanced courses in dynamics.","Dynamics; Mechanical Engineering; Physics; Kinematics; Kinetics","en","book","TU Delft OPEN Publishing","978-94-6366-795-1","","","","","","","","","Dynamics of Micro and Nano Systems","","",""
"uuid:8e213072-5117-41f0-b9f0-2cc35a8ebc96","http://resolver.tudelft.nl/uuid:8e213072-5117-41f0-b9f0-2cc35a8ebc96","Exploring Multidimensional Modularity: Strategies to Reduce Complexity in Design Activities","Tan, T. (The University of Hong Kong); Mills, Grant (University College London (UCL)); Papadonikolaki, E. (TU Delft Integral Design & Management)","","2024","Modularity is an approach to simplify systems and reduce complexity. However, existing research suggests that a mono-dimensional modularity strategy, focusing solely on one dimension, such as product, process, or organization, might not fully achieve these goals in design activities. This research investigates how combining strategies from various dimensions of modularity can reduce the complexity of large-scale engineering design. The Huoshenshan Hospital, a 1,000-bed hospital designed and built in 10 days, provided an extreme case study of the first emergency hospital to address COVID-19. The research identified 10 different aspects, termed ‘proximities’, which relate to how people perceive the four dimensions of modularity, specifically across organization–process–product–supply-chain dimensions. Additionally, it identified three types of reinforcement relationships aimed at diminishing complexity in design activities: modular alignment (i.e., synchronized alignment and asynchronous alignment), modular complementarity (i.e., subtraction complement and addition complement), and modular incentive relationships. This research highlights that these three types of reinforcement relationships between different dimensions of modularity can reduce complexity, allowing subsystems to support the system in working as a whole.","modularity; engineering design; design activities; construction; case study","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-07-23","","","Integral Design & Management","","",""
"uuid:dbb987f9-4b41-487a-b7e3-1286db7d2d4e","http://resolver.tudelft.nl/uuid:dbb987f9-4b41-487a-b7e3-1286db7d2d4e","Spatial Design Thinking in Coastal Defence Systems: Overtopping Dikes in Southend-On-Sea","Iuorio, Luca (TU Delft Environmental Technology and Design); Wüthrich, D. (TU Delft Hydraulic Structures and Flood Risk); Teng, Djimin (Student TU Delft); Hooimeijer, F.L. (TU Delft Environmental Technology and Design)","","2024","Coastal dikes have been built for millennia to protect inhabited lands from exceptional high tides and storm events. Currently, many European countries are developing specific programs to integrate the construction of new dikes (or the raising of existing ones) into the built environment to face sea level rising. Technical difficulties in succeeding in this operation are questioning the paradigm of protection for the long term, pointing out the need for alternative strategies of adaptation that are not yet fully explored. This paper elaborates on innovative models to deal with coastal flooding, presenting the results of an interdisciplinary research and design process for the case-study of Southend-on-Sea (UK). Detailed numerical simulations are used to develop a spatial strategy to accommodate water during extreme events, introducing different prototypes of dike designs that include seawalls, enhanced roughness through rock and stepped revetments, as well as vegetation. The overall goal is to push forward the traditional approach of planning water protection infrastructure within the solely field of civil engineering. It elaborates on the integration of the disciplines of spatial design and engineering and presents novel advances in terms of spatial design for the revetment of overtopping dikes.","engineering; spatial design; interdisciplinary; coastal dikes; roughness","en","journal article","","","","","","","","","","","Environmental Technology and Design","","",""
"uuid:cf52ea5d-6ad8-48f1-8fb3-03f42fe3c3a5","http://resolver.tudelft.nl/uuid:cf52ea5d-6ad8-48f1-8fb3-03f42fe3c3a5","Self-healing of cementitious materials using sustainable cenosphere-based manufactured aggregate","Lv, Leyang (Shenzhen University); Zhang, Xiangyu (Shenzhen University); Šavija, B. (TU Delft Materials and Environment); Zhang, Mingzhong (University College London (UCL)); Han, Kaihang (Shenzhen University); Zhang, Honghzhi (Shandong University); Pei, Chun (Shenzhen University); Zhu, Jihua (Shenzhen University); Xing, Feng (Shenzhen University)","","2024","Self-healing concrete using encapsulated healing agent has shown great potential in enhancing concrete durability. However, the capsules are expensive to make and can lower the mechanical properties of concrete. In this study, a new type of manufactured aggregate that employs waste-derived fly ash cenosphere as a carrier of healing agent (SH-CS) was designed and produced. The effect of SH-CS incorporation on hydration, engineering properties and self-healing efficiency of cement mortar was systematically evaluated, with a special focus on self-healing mechanism through the analysis of the mineral composition of the healing product. The results indicate that the prepared SH-CS has good stability in and compatibility with cement mortar. The addition of SH-CS has small influence on the fresh properties of cement mortar and less negative effect on compressive strength at the hardened stage compared to the existing study. By replacing 3 wt.% of fine aggregate with SH-CS, up to 71% of the crack opening area of mortar specimens with a crack width of about 0.3 mm was self-healed after 28 days of water exposure. The self-healing behaviour of SH-CS led to a maximal 41% drop in water adsorption and contributed to the recovery of flexural strength. The healing products precipitated on the fracture surface were mainly composed of amorphous C-S-H and Calcite. It can be estimated that incorporating SH-CS in concrete would result in only a moderate (∼29%) rise in cost for C40 concrete.","Cenosphere; Encapsulated healing agent; Engineering properties; Hydration; Microstructure; Self-healing concrete","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-08-21","","","Materials and Environment","","",""
"uuid:d0202570-790a-4a6b-99df-e73bb0edcebc","http://resolver.tudelft.nl/uuid:d0202570-790a-4a6b-99df-e73bb0edcebc","Effect of stacking fault energy on the thickness and density of annealing twins in recrystallized FCC medium and high-entropy alloys","Schneider, Mike (Ruhr-Universität Bochum; PSL Research University); Couzinié, Jean Philippe (Université Paris-Est Créteil); Shalabi, Amin (Ruhr-Universität Bochum); Ibrahimkhel, Farhad (Ruhr-Universität Bochum); Ferrari, A. (TU Delft Team Marcel Sluiter); Körmann, F.H.W. (TU Delft Team Marcel Sluiter; Max-Planck-Institut für Eisenforschung; Bundesanstalt für Materialforschung und -prüfung (BAM)); Laplanche, Guillaume (Ruhr-Universität Bochum)","","2024","This work aims to predict the microstructure of recrystallized medium and high-entropy alloys (MEAs and HEAs) with a face-centered cubic structure, in particular the density of annealing twins and their thickness. Eight MEAs and five HEAs from the Cr-Mn-Fe-Co-Ni system are considered, which have been cast, homogenized, cold-worked and recrystallized to obtain different grain sizes. This work thus provides a database that could be used for data mining to take twin boundary engineering for alloy development to the next level. Since the stacking fault energy is known to strongly affect recrystallized microstructures, the latter was determined at 293 K using the weak beam dark-field technique and compared with ab initio simulations, which additionally allowed to calculate its temperature dependence. Finally, we show that all these data can be rationalized based on theories and empirical relationships that were proposed for pure metals and binary Cu-based alloys.","CoCrFeMnNi HEAs and MEAs; Electron backscatter diffraction; Grain boundary engineering; Recrystallization; Transmission electron microscopy (TEM)","en","journal article","","","","","","","","","","","Team Marcel Sluiter","","",""
"uuid:cbab1401-ba29-49e0-8427-951ee475176b","http://resolver.tudelft.nl/uuid:cbab1401-ba29-49e0-8427-951ee475176b","Synthetic Biology to Engineer Bacteriophage Genomes","Martins Costa, A.R. (TU Delft BN/Stan Brouns Lab); Azeredo, Joana (University of Minho); Pires, Diana Priscila (University of Minho)","Azeredo, Joana (editor); Sillankorva, Sanna (editor)","2024","Recent advances in the synthetic biology field have enabled the development of new molecular biology techniques used to build specialized bacteriophages with new functionalities. Bacteriophages have been engineered toward a wide range of applications, including pathogen control and detection, targeted drug delivery, or even assembly of new materials. In this chapter, two strategies that have been successfully used to genetically engineer bacteriophage genomes will be addressed: the bacteriophage recombineering of electroporated DNA (BRED) and the yeast-based phage-engineering platform.","Bacteriophage; Bacteriophage engineering; BRED; YAC","en","book chapter","Humana Press Inc.","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-26","","","BN/Stan Brouns Lab","","",""
"uuid:aa9977c0-85d9-451b-9b1c-0337c67d9236","http://resolver.tudelft.nl/uuid:aa9977c0-85d9-451b-9b1c-0337c67d9236","Frankenstein: fast and lightweight call graph generation for software builds","Keshani, M. (TU Delft Software Engineering); Gousios, G. (TU Delft Software Technology; Endor Labs); Proksch, S. (TU Delft Software Engineering)","","2024","Call Graphs are a rich data source and form the foundation for advanced static analyses that can, for example, detect security vulnerabilities or dead code. This information is invaluable when it is immediately available, such as in the output of a build system. Call Graph generation is a whole-program analysis: not just the application, but also all its dependencies are processed together. Recent work has shown that even advanced static analyses can use summarization techniques to substantially improve runtime; however, existing analyses focus on soundness, and as such remain very expensive. When executed in the build system, which typically has limited resources, even powerful servers suffer from slow build times, rendering these analyses impractical in today’s fast-paced development. In this paper, we aim to strike a balance between improving static analyses while remaining practical for use cases that require quick results in low-resource environments. We propose a summarization-based implementation of a Class-Hierarchy Analysis algorithm for call graph generation of Java programs. Our approach leverages the fact that dependency sets often do not change between builds: we can generate call graphs for these dependencies, cache their generation for subsequent builds, and using a novel stitching algorithm, Frankenstein, merge all partial results into a complete call graph for the whole program. Our evaluation results show that this lightweight approach can substantially outperform existing frameworks. In terms of speed improvements, Frankenstein surpasses the baselines by up to 38%, requiring an average of just 388 Megabytes of memory. This makes the proposed approach practical for build systems with limited memory resources. Despite these optimizations, our generated call graphs maintain a near-identical set of edges when compared to the baselines, achieving an F 1 score of up to 0.98. This summarization-based approach for call graph generation paves the way for using extended static analyses in build processes.","Build systems; Call graph generation; Software ecosystems; Software engineering in practice","en","journal article","","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:7b36b99f-0616-4d8c-8a7e-a46f6b73abd2","http://resolver.tudelft.nl/uuid:7b36b99f-0616-4d8c-8a7e-a46f6b73abd2","A CPT-based multi-spring model for lateral monopile analysis under SLS conditions in sand","Tott-Buswell, Jacques (University of Nottingham); Prendergast, Luke J. (University of Nottingham); Gavin, Kenneth (TU Delft Geo-engineering)","","2024","Monopiles are the most common Offshore Wind Turbine (OWT) foundations due to their simplicity in design, fabrication, and installation. However, large new-generation turbines have led to significant changes in monopile dimensions, necessitating extensive finite element analyses and ground investigations to meet design requirements. While Cone Penetration Test (CPT)-based p-y methods can analyse slender pile lateral behaviour, they often miss additional resistance mechanisms relevant to rigid monopiles. This paper introduces CPT-informed resistance mechanisms for monopiles to incorporate additional lateral resistances beyond p-y modelling capabilities. Distributed moment–rotation (m-θ) springs are defined by repurposing CPT-based axial capacity estimation methods for piles; and pile tip shear and moment springs are informed by approximating a residual bearing stress post-installation using local CPT qc values. The performance of the multi-spring model is appraised against data reported from monotonic pile pushover tests conducted at two sand sites. Results show that the multi-spring model is capable of predicting pile head deflections reasonably well within serviceability deflection limits against the reported test data, but ultimate failure loads cannot be predicted using the proposed model. A clear sensitivity in pile response to local variations in CPT qc is demonstrated.","In-situ testing; Numerical modelling; Offshore engineering; Piles & piling; Soil–structure interaction","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:08e0f52f-c2ce-49a9-8d6f-a4f7c97a5145","http://resolver.tudelft.nl/uuid:08e0f52f-c2ce-49a9-8d6f-a4f7c97a5145","Unravelling corrosion degradation of aged aircraft components protected by chromate-based coatings","Cornet, A.J. (TU Delft Team Arjan Mol; Royal Netherlands Air Force); Homborg, A.M. (TU Delft Team Arjan Mol; Netherlands Defence Academy); Ravi Anusuyadevi, P. (TU Delft Team Arjan Mol); 't Hoen-Velterop, L. (National Aerospace Laboratory, Marknesse); Mol, J.M.C. (TU Delft Team Arjan Mol)","","2024","Despite extensive research, eliminating hexavalent chromium-based inhibitors from aerospace coatings remains challenging due to a lack of understanding of coating degradation during aircraft service. This study addresses the issue by investigating the protective mechanisms and aging processes of chromate-containing coatings on aircraft components after service for over 35 years. Four aircraft parts underwent visual inspection, disassembly, and analysis using scanning electron microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). While most coating areas remained intact after extended use, three distinct degradation modes were identified: tip erosion, corrosion around rivets, and corrosion around fasteners at the leading edge. These findings reveal the complexity of corrosion protection, emphasizing that hexavalent chromium-containing coatings may not offer comprehensive protection at local design heterogeneities. The study also highlights the need to revisit traditional laboratory analysis protocols based on accelerated corrosion testing of oversimplified sample configurations, given the revealed end-of-service failure mechanisms.","Aerospace engineering; Structures; Aluminium alloy; Composites; Fasteners; Microscopic characterization and microanalysis; Corrosion; Manufacturing defect; Isolation; Drain holes","en","journal article","","","","","","","","","","","Team Arjan Mol","","",""
"uuid:e2fbd8b6-2a09-4eba-afaa-f5a3126b59f5","http://resolver.tudelft.nl/uuid:e2fbd8b6-2a09-4eba-afaa-f5a3126b59f5","High-resolution turbofan intake flow characterization by automated stereoscopic-PIV in an industrial wind tunnel environment","Ujjaini Kempaiah, K. (TU Delft Aerodynamics; LaVision); Piovesan, Tommaso (Cranfield University); Zachos, Pavlos K. (Cranfield University); Michaelis, Dirk (LaVision); Gebbink, Roy (German-Dutch Wind Tunnels); van Rooijen, Bart (German-Dutch Wind Tunnels); Prieto, Daniel Gil (Rolls-Royce plc); MacManus, David (Cranfield University); Sciacchitano, A. (TU Delft Aerodynamics); Sheaf, Christopher (Rolls-Royce plc)","","2024","Unsteady inlet flow distortion can influence the stability and performance of any propulsion system, in particular for more novel, short and slim intakes of future aero-engine configurations. As such, the requirement for measurement methods able to provide high spatial resolution data is important to aid the understanding of these flow fields. This work presents flow field characterisations at a crossflow plane within a short aeroengine intake using stereoscopic particle image velocimetry (SPIV). A series of tests were conducted across a range of crosswind and high angle of attack conditions for a representative short and slim aspirated intake configuration at two operating points in terms of mass flow rate. The velocity maps were measured at a crossflow plane within the intake at an axial position L/D = 0.058 from where a fan is expected to be installed. The diameter of the measurement plane was 250 mm, and the final spatial resolution of the velocity fields had a vector pitch of 1.5 mm which is at least two orders of magnitude richer than conventional pressure-based distortion measurements. The work demonstrates the ability to perform robust non-intrusive flow measurements within modern intake systems in an industrial wind tunnel environment across a wide range of operating conditions; hence, it is suggested that SPIV can potentially become part of standard industrial testing. The results provide rich datasets that can notably improve our understanding of unsteady distortions and influence the design of novel, closely coupled engine-intake systems.","industrial wind tunnel testing; inlet distortion; inlet testing; non-intrusive measurements; particle image velocimetry; turbofan; ultra high bypass ration engines","en","journal article","","","","","","","","","","","Aerodynamics","","",""
"uuid:6f94c28c-fbae-458e-a757-6331d1561b25","http://resolver.tudelft.nl/uuid:6f94c28c-fbae-458e-a757-6331d1561b25","Incorporating strontium enriched amorphous calcium phosphate granules in collagen/collagen-magnesium-hydroxyapatite osteochondral scaffolds improves subchondral bone repair","Xu, J. (Erasmus MC); Vecstaudza, Jana (Riga Technical University); Wesdorp, Marinus A. (Erasmus MC); Labberté, Margot (University College Dublin); Salerno, Manuela (Rizzoli Orthopaedic Institute); Kok, Joeri (Eindhoven University of Technology); van Rietbergen, Bert (Eindhoven University of Technology); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Locs, Janis (Riga Technical University); Brama, Pieter A.J. (University College Dublin)","","2024","Osteochondral defect repair with a collagen/collagen-magnesium-hydroxyapatite (Col/Col-Mg-HAp) scaffold has demonstrated good clinical results. However, subchondral bone repair remained suboptimal, potentially leading to damage to the regenerated overlying neocartilage. This study aimed to improve the bone repair potential of this scaffold by incorporating newly developed strontium (Sr) ion enriched amorphous calcium phosphate (Sr-ACP) granules (100–150 μm). Sr concentration of Sr-ACP was determined with ICP-MS at 2.49 ± 0.04 wt%. Then 30 wt% ACP or Sr-ACP granules were integrated into the scaffold prototypes. The ACP or Sr-ACP granules were well embedded and distributed in the collagen matrix demonstrated by micro-CT and scanning electron microscopy/energy dispersive x-ray spectrometry. Good cytocompatibility of ACP/Sr-ACP granules and ACP/Sr-ACP enriched scaffolds was confirmed with in vitro cytotoxicity assays. An overall promising early tissue response and good biocompatibility of ACP and Sr-ACP enriched scaffolds were demonstrated in a subcutaneous mouse model. In a goat osteochondral defect model, significantly more bone was observed at 6 months with the treatment of Sr-ACP enriched scaffolds compared to scaffold-only, in particular in the weight-bearing femoral condyle subchondral bone defect. Overall, the incorporation of osteogenic Sr-ACP granules in Col/Col-Mg-HAp scaffolds showed to be a feasible and promising strategy to improve subchondral bone repair.","Amorphous calcium phosphate; Osteochondral defect; Regenerative medicine; Strontium; Tissue engineering","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:01775ed6-97c1-4264-9ec8-a686e195a771","http://resolver.tudelft.nl/uuid:01775ed6-97c1-4264-9ec8-a686e195a771","A versatile in situ cofactor enhancing system for meeting cellular demands for engineered metabolic pathways","Jaroensuk, Juthamas (Vidyasirimedhi Institute of Science and Technology); Sutthaphirom, Chalermroj (Vidyasirimedhi Institute of Science and Technology); Phonbuppha, Jittima (Vidyasirimedhi Institute of Science and Technology); Chinantuya, Wachirawit (Vidyasirimedhi Institute of Science and Technology; Mahidol University); Kesornpun, Chatchai (Vidyasirimedhi Institute of Science and Technology); Akeratchatapan, Nattanon (Vidyasirimedhi Institute of Science and Technology); Kittipanukul, Narongyot (Vidyasirimedhi Institute of Science and Technology); Phatinuwat, Kamonwan (Chulabhorn Graduate Institute, Bangkok); Hollmann, F. (TU Delft BT/Biocatalysis)","","2024","Cofactor imbalance obstructs the productivities of metabolically engineered cells. Herein, we employed a minimally perturbing system, xylose reductase and lactose (XR/lactose), to increase the levels of a pool of sugar phosphates which are connected to the biosynthesis of NAD(P)H, FAD, FMN, and ATP in Escherichia coli. The XR/lactose system could increase the amounts of the precursors of these cofactors and was tested with three different metabolically engineered cell systems (fatty alcohol biosynthesis, bioluminescence light generation, and alkane biosynthesis) with different cofactor demands. Productivities of these cells were increased 2-4-fold by the XR/lactose system. Untargeted metabolomic analysis revealed different metabolite patterns among these cells, demonstrating that only metabolites involved in relevant cofactor biosynthesis were altered. The results were also confirmed by transcriptomic analysis. Another sugar reducing system (glucose dehydrogenase) could also be used to increase fatty alcohol production but resulted in less yield enhancement than XR. This work demonstrates that the approach of increasing cellular sugar phosphates can be a generic tool to increase in vivo cofactor generation upon cellular demand for synthetic biology.","alkane; bioluminescence; fatty alcohol; metabolic engineering; sugar phosphate; synthetic biology; xylose reductase","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:edaba1eb-4d33-4957-b21e-f3b66e584c90","http://resolver.tudelft.nl/uuid:edaba1eb-4d33-4957-b21e-f3b66e584c90","Substrate-Specific Evolution of Amine Dehydrogenases for Accessing Structurally Diverse Enantiopure (R)-β-Amino Alcohols","Yin, Xinjian (Sun Yat-sen University); Gong, Wenzhong (Sun Yat-sen University); Zeng, Yujing (Sun Yat-sen University); Qiu, Hulin (Sun Yat-sen University); Liu, Lan (Sun Yat-sen University); Hollmann, F. (TU Delft BT/Biocatalysis); Chen, Bishuang (Sun Yat-sen University)","","2024","The biocatalytic oxidative deamination of β-amino alcohols holds significant practical potential in kinetic resolution and/or deracemization process to access (R)-β-amino alcohols. This study exemplifies a notable instance of acquisition and utilization of this valuable oxidative deamination activity. Initially, the mutation N261M (M0) was identified to endow a native valine dehydrogenase with oxidative deamination activity toward a few (S)-β-amino alcohols. Subsequently, a phylogenetic analysis-guided, double-code saturation mutagenesis strategy was proposed to engineer M0's side-chain binding site. This strategy facilitated the substrate-specific evolution of M0, resulting in the creation of a panel of mutants (M1-M4) with noteworthy oxidative deamination activity toward structurally diverse (S)-β-amino alcohols. Using these engineered amine dehydrogenases, termed as β-amino alcohol dehydrogenases (β-AADHs), the complete kinetic resolution and even deracemization of a range of β-amino alcohols have been achieved. This work reports distinct biocatalysts and a synthetic strategy for the synthesis of enantiopure (R)-β-amino alcohols and offers an innovative approach for substrate-specificity engineering of enzymes.","amine dehydrogenases; biocatalysis; enantiopure β-amino alcohols; oxidative deamination; protein engineering","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:087073a1-0685-434b-ba33-ac7d93d294a1","http://resolver.tudelft.nl/uuid:087073a1-0685-434b-ba33-ac7d93d294a1","What is an app store? The software engineering perspective","Zhu, Wenhan (David R. Cheriton School of Computer Science); Proksch, S. (TU Delft Software Engineering); German, Daniel M. (University of Victoria); Godfrey, Michael W. (David R. Cheriton School of Computer Science); Li, Li (Beihang University); McIntosh, Shane (David R. Cheriton School of Computer Science)","","2024","“App stores” are online software stores where end users may browse, purchase, download, and install software applications. By far, the best known app stores are associated with mobile platforms, such as Google Play for Android and Apple’s App Store for iOS. The ubiquity of smartphones has led to mobile app stores becoming a touchstone experience of modern living. App stores have been the subject of many empirical studies. However, most of this research has concentrated on properties of the apps rather than the stores themselves. Today, there is a rich diversity of app stores and these stores have largely been overlooked by researchers: app stores exist on many distinctive platforms, are aimed at different classes of users, and have different end-goals beyond simply selling a standalone app to a smartphone user. The goal of this paper is to survey and characterize the broader dimensionality of app stores, and to explore how and why they influence software development practices, such as system design and release management. We begin by collecting a set of app store examples from web search queries. By analyzing and curating the results, we derive a set of features common to app stores. We then build a dimensional model of app stores based on these features, and we fit each app store from our web search result set into this model. Next, we performed unsupervised clustering to the app stores to find their natural groupings. Our results suggest that app stores have become an essential stakeholder in modern software development. They control the distribution channel to end users and ensure that the applications are of suitable quality; in turn, this leads to developers adhering to various store guidelines when creating their applications. However, we found the app stores operational model could vary widely between stores, and this variability could in turn affect the generalizability of existing understanding of app stores.","App store; Empirical software engineering; Software distribution; Software release","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-07-02","","","Software Engineering","","",""
"uuid:dcfaea53-3e8a-46c5-82a5-95c360861277","http://resolver.tudelft.nl/uuid:dcfaea53-3e8a-46c5-82a5-95c360861277","Draft genome sequence of the Saccharomyces cerevisiae SpyCas9 expressing strain IMX2600, a laboratory and platform strain from the CEN.PK lineage for cell-factory research","van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Ortiz Merino, R.A. (TU Delft Research Data and Software); Bennis, N.X. (TU Delft BT/Industriele Microbiologie); Wronska, A.K. (TU Delft BT/Industriele Microbiologie); Else-Hassing, J. (TU Delft BT/Industriele Microbiologie); Daran-Lapujade, P.A.S. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2024","The biobased-economy aims to create a circular biotechnology ecosystem to transition from a fossil fuel-based to a sustainable industry based on biomass. For this, new microbial cell-factories are essential. We present the draft genome of the CEN.PK-derived Saccharomyces cerevisiae SpyCas9 expressing strain (IMX2600), that serve as chassis of new cell-factories.","biotechnology; cell factory; CRISPR; metabolic engineering; Saccharomyces cerevisiae","en","journal article","","","","","","Publisher Copyright: Copyright © 2023 van den Broek et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.","","","","","BT/Industriele Microbiologie","","",""
"uuid:c7f2ab48-896c-4d09-adc3-afcc12b64c1b","http://resolver.tudelft.nl/uuid:c7f2ab48-896c-4d09-adc3-afcc12b64c1b","What is conceptual disruption?","Marchiori, S. (TU Delft Ethics & Philosophy of Technology); Scharp, Kevin (University of Illinois at Urbana-Champaign; University of Twente)","","2024","Recent work on philosophy of technology emphasises the ways in which technology can disrupt our concepts and conceptual schemes. We analyse and challenge existing accounts of conceptual disruption, criticising views according to which conceptual disruption can be understood in terms of uncertainty for conceptual application, as well as views assuming all instances of conceptual disruption occur at the same level. We proceed to provide our own account of conceptual disruption as an interruption in the normal functioning of concepts and conceptual schemes. Moreover, we offer a multilevel taxonomy thereof, where we distinguish between instances of conceptual disruptions occurring at different levels (conceptual scheme, conceptual clusters, and individual concepts), taking on different forms (conceptual gaps and conceptual conflicts), and leading to different degrees of severity (extending from mild to severe). We also provide detailed accounts through historical examples of how conceptual gaps and conceptual conflicts can occur at different times in the very same process of conceptual disruption. Finally, we make the case that different kinds of conceptual engineering can provide meaningful ways to assess and overcome distinct types of conceptual disruption.","Conceptual disruption; Conceptual engineering; Socially disruptive technologies; Conceptual gap; Conceptual conflict; Conceptual overlap; Conceptual change; Philosophy of technology","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:cb6444be-f094-46bd-9b51-2df2ab00dba8","http://resolver.tudelft.nl/uuid:cb6444be-f094-46bd-9b51-2df2ab00dba8","Transforming Engineering Education in Learning Ecosystems for Resilient Engineers","Klaassen, R.G. (TU Delft Policy & Implementation); Hellendoorn, J. (TU Delft Cognitive Robotics); Bossen, R.H. (TU Delft Education and Student Affairs)","","2024","TU Delft education system is transformed on three levels: 1) new courses and projects in existing B.Sc. and M.Sc. programs for multidisciplinary and reflective learning; 2) new M.Sc. programs focusing on multi and interdisciplinarity, personal development, and professional skills; and 3) central Interdisciplinary Projects for Master Students from different programs. With these steps, the university offers students a learning ecosystem where identity-building can occur, fosters interdisciplinary teamwork, and strong interaction with the professional world and government is necessary to finish projects. In this article, the ecosystem will be explained, and results will be shared of surveys among students who experienced learning in the learning ecosystem. The surveys show that students under stand their future role in the community as engineers, feel that they have acquired new skills, feel better about framing complex problems, and are more competent to work in the industry.","Curriculum Renewal; Future Engineer; ecosystem; stakeholders; knolwedge engineering; education; ethics; teamwork; survey","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-18","","Cognitive Robotics","Policy & Implementation","","",""
"uuid:ef90ef42-4c18-41aa-aad4-b45e574a2929","http://resolver.tudelft.nl/uuid:ef90ef42-4c18-41aa-aad4-b45e574a2929","Performance of Immersed Tunnels subjected to Settlements: Noordtunnel Case Study","van der Heijden, M. (TU Delft Concrete Structures; Rijkswaterstaat)","","2023","In the next decades, Rijkswaterstaat will renovate many existing immersed tunnels so they can meet their intended lifespan in a good condition. Ongoing settlements could be a threat to the tunnel structural performance, as deformation may cause structural damage. Currently, immersed tunnels are subjected to greater and more uneven settlements than considered in the design. The issue of these ongoing settlements is mainly concentrated in the segment joints, which have typically been executed by a spigot and socket structure to prevent differential settlements. Significant deformation of the tunnel structure could result in concrete cracking, which entails the risks of structural connection loss, tunnel misalignment, and leakages (leading to durability reduction and damage to installations). This could impact the reliability of the structure over time, and consequently affect the availability of the road network. Therefore, the key objective of this research is how to assess the structural reliability and tunnel availability, and to investigate in which way the performance of existing immersed tunnel structures could be optimised given the ongoing settlements. Assessing the residual lifespan is beyond the scope, but optimising the tunnel performance during the remaining operational life is the main motivation for this research project. The research methodology consists of a parametric structural model, which determines the tunnel reliability and availability by using a Monte Carlo approach. The Noordtunnel case is used to demonstrate the research methodology, as this tunnel showed excessive settlements and a major renovation will be performed in the coming years. Additionally, the maintenance and renovation strategy for the segment joints in immersed tunnels are examined, to optimise the performance throughout the residual lifespan.","Immersed Tunnel; Settlements; Structural Performance; Existing Infrastructure; Segment Joints; Leakages; Noordtunnel; Rijkswaterstaat; Engineering Doctorate","en","report","","","","","","","","","","","Concrete Structures","","",""
"uuid:102edff8-8960-4633-830c-369aef8e279f","http://resolver.tudelft.nl/uuid:102edff8-8960-4633-830c-369aef8e279f","Amsterdam quays under pressure: Modelling and testing of historic canal walls","Hemel, M. (TU Delft Hydraulic Structures and Flood Risk)","Jonkman, Sebastiaan N. (promotor); Peters, D.J. (copromotor); Korff, M. (copromotor); Delft University of Technology (degree granting institution)","2023","Amsterdam faces the challenge of maintaining a domain of 200 km historic quay walls, which is a vital part of the city’s historical landscape. Many quays are currently in poor condition and require renovation or replacement in the near future, significantly impacting the city. The quay walls can be up to 300 years old and their structure consists of a masonry cantilever wall on top of a timber floor, which is supported by headstocks founded on multiple vertical timber pile rows. In recent years, quay walls have shown signs of damage, partial collapse, and early warnings of such events. The most recent and severe incident was the collapse of the Grimburgwal in 2020, where approximately 20 meters of quay wall suddenly collapsed, plunging into the canal within a matter of seconds. Consequently, it is important to be able to predict the resistance of these structures and understand their potential failure mechanisms. The most common and severe failure mechanism observed in Amsterdam’s city centre is the lateral failure of the pile foundation. Calculating the resistance against this mechanism with existing models, leads to estimates of insufficient strength and safety. It seems that these models are too conservative, because in reality, the majority of the existing structures that proof unsafe on paper is performing quite well in practice. The discrepancy between the models and reality arises from uncertainties in the working principles of historic quay walls, geometrical unknowns, as well as uncertainties in soil and structural properties.
This thesis provides a comprehensive understanding of the lateral failure of the pile foundation by full-scale quay wall experiments and it proposes a computational model to predict the resistance against this failure mechanism.
To gain a comprehensive understanding of the lateral failure mechanism, an unique and extensive experimental program has been conducted on an existing historic quay wall, founded on timber piles. The quay is located at Amsterdam Overamstel and dates back to 1905. Experiments have been conducted at three different system levels. At level 1, four-point bending experiments have been performed on individual piles to obtain the bending material properties. At level 2, lateral pile group experiments have been conducted on two 3x4 pile groups to study the pile-soil-pile interactions. At level 3, proof load experiments have been carried out on entire full scale quay wall sections, to study the overall behaviour of the quay. As part of the experimental program, an extensive geotechnical site investigation has been performed. The experimental approach chosen enables a stepwise validation and calibration for computational quay wall models.
Through the experimental program, it is demonstrated that among all potential failure mechanisms, the lateral failure mechanism is most likely to occur when a quay wall is subjected to large surface loading at its backside. Examples of such loads in practice are parked or moving cars, heavy vehicles or goods. The mechanism is triggered by an increase in soil stresses at the backside of the quay, which pushes the foundation towards the water. This, in turn, results in the bending of the timber piles, accompanied by the development of bending stresses. State-of-the-art models (ABAQUS, PLAXIS and spring models) were used to predict the failure surface load of the Overamstel quay, with an estimated value of approximately 20kPa. However, in reality, the quay demonstrated significantly greater strength, as failure was not observed even for loads as high as 55kPa. While part of this underprediction can be attributed to experiment-specific effects not considered in the prediction analysis, the substantial underprediction of the failure load still emphasizes the conservatism in current modelling approaches.
Clear indicators of the lateral failure mechanism include the inclined position of the top of the piles, broken piles, settlements at the backside of the quay, and lateral deflection of the foundation. These indicators can effectively be monitored, as demonstrated by the employed monitoring plan in the experiments. Elements of this plan, such as inclination sensors mounted on the pile caps, can be implemented in Amsterdam’s city centre to detect signs of lateral failure. The foundation piles experience fracture when they reach a state of full yielding, which occurs when the bending stresses in the timber surpass the modulus of rupture across the entire cross-section of the pile. Bending experiments conducted on timber piles indicate a substantial variance in both the modulus of rupture (variation coefficient of 0.26) and the modulus of elasticity (variation coefficient of 0.3). Consequently, the piles exhibit a wide range of flexural stiffnesses and bending moment capacities. These discrepancies stem from natural variability and biological degradation of the timber, which lead to the formation of a weakened outer layer or “soft shell” starting at the perimeter of the piles, going inward. The soft shell thickness is approximately 10% of the external pile diameter and it does not contribute to the structural strength of the piles.
The substantial variations in load carrying capacities within a timber pile group can be primarily attributed to the variations in pile stiffness and bending capacity. Surprisingly, typical pile group effects such as in-line, side-by-side, pile free height, and pile diameters do not have a large contribution to the variations in individual lateral pile resistances found. When multiple piles are considered together, significant variations between individual piles compensate each other, leading to a group resistance that was almost identical in the two pile group experiments. This finding is advantageous from a computational modelling and risk assessment standpoint. Within the tested pile groups at the Overamstel site, with 200-300 mm diameter piles, partial yielding starts at approximately 100 mm of group deflection. The first pile breakages are expected to initiate at 140 mm of deformation; however, due to the redistribution of lateral loads among the piles, it does not directly result in group failure. Nevertheless, when deformations exceed 200 mm, a majority of the piles will break, leading to group failure. It is vital to emphasize that the transition from the initial onset of yielding to group failure requires merely a slight additional lateral load of 15%.
An analytical quay wall model has been developed to predict the resistance against lateral failure of historic quay walls. This model comprises a framework of elastic beams embedded in an elastic foundation, which is externally loaded by a linear elastic soil model based on Flamant’s theory. The framework is made up of multiple Euler-Bernoulli beams, connected to each other by boundary and interface conditions. The stiffness of the connection between piles and headstock is described by a pile-headstock interface model. The elastic foundation is represented by a series of independent p-y springs, approximated with a bilinear elastic-perfect-plastic model. A method is developed to include the pile-soil-pile interaction and the influence of a sloping surface by adjusting the plastic branch of the p-y springs. This method has been validated through multiple experiments documented in literature in which steel piles were used, eliminating material property uncertainties. The analytical quay wall model has been validated and calibrated with the Overamstel quay wall experiments, employing the stepwise approach. In the first step, the bending properties of the timber piles were obtained from the level 1 bending experiments. Subsequently, in the second step, the model’s capability to describe laterally loaded pile groups was validated through the level 2 pile group experiments. Finally, the Flamant soil model and the model’s ability to describe a historic quay were validated using the level 3 quay experiments. As a final step, the model was compared with finite element computations, demonstrating a good agreement in displacements and forces. The analytical quay wall model accurately predicts lateral displacement, pile bending moments, and bending stresses at various depths, allowing for the assessment of pile fracture under specific surface loads. Its key advantages over state-of-the-art finite element modelling software include robustness, computational speed, feedback loops (e.g. force and displacement-dependent pile-headstock connection stiffnesses), minimal input requirements, and no numerical stability issues at large deformations. The model is highly suitable for trend analysis, sensitivity studies, and probabilistic analysis due to its short computational time in seconds, compared to complex three-dimensional FEM software that takes minutes to hours. The effectiveness and potential of the validated analytical quay wall model have been demonstrated in two “follow up” studies, described below.
In the first study, the quay model has been employed to investigate the failure of the Grimburgwal. With the model it was demonstrated that bending stresses in the timber piles exceeded the modulus of rupture as a consequence of local deepening of the canal in front of the quay. It therefore provides valuable insights for Amsterdam’s historical centre. The analyses have served as an additional validation step for the analytical quay wall model developed in this thesis, specifically for applications to the quay walls of Amsterdam’s historical centre.
In the second study the quay model has been used to effectively showcase the potential of Bayesian updating by incorporating evidence of survived loading situations and corresponding deformations. This approach enables refinement of the reliability predictions and parameter distribution uncertainties, leading to a more accurate prediction of the resistance against the lateral failure mechanism of quay wall foundation piles. Depending on the type of evidence, an a-priori reliability prediction for a quay wall that fails to meet safety standards can be updated to any of the three consequence classes (CC3, CC2, and CC1b) outlined in NEN8700. In a fictive case study, a quay wall with an a-priori reliability of β = 1.5 has been increased to β = 3.2 by including evidence of an extreme survived load of 10 kN/m2 that resulted in displacements of less than 4mm. This is a decrease in failure probability by two orders of magnitude, showing the potential impact of using observational information in combination with Bayesian updating
The main practical implication of this thesis has been the improvement in modelling accuracy, as a result of the Overamstel experiments. The revised “gain” in modelling accuracy for bending moments and deflection was 43% and 37% respectively. This improvement can be attributed to advancements in modelling techniques, such as accurately simulating pile-soil-pile interaction and modelling the pile-headstock connection, as well as utilizing precise location-specific geotechnical and structural material properties as model input. The improved modelling accuracy results in a less conservative evaluation of the quay walls, leading to a reduction in the number of unnecessarily rejected quay walls for the Amsterdam quay wall domain.
The most practical recommendations for Amsterdam are: a) to develop accurate techniques for mapping quay wall configurations, b) to implement comprehensive quay wall monitoring systems in the city centre, c) to utilize the analytical model in future studies and assessments, d) prioritize geotechnical site investigations before making model predictions, and e) perform non-destructive tests in the city centre and incorporate this information in the assessment.
The methods and insights developed in this dissertation enhance the understanding of the lateral failure of historic quay walls and enable more precise predictions of their resistance against such failures. As such, the model can be effectively used to support decisions on their safe use, remaining service life, and the need for their replacement.","Historic quay walls; Experiments; Bending tests; Overloading tests; Lateral pile group experiments; Quay wall modelling; Analytical models; Forensic engineering; Bayesian updating; Reliablity updating; Amsterdam","en","doctoral thesis","","978-94-6469-656-1","","","","Analytical quay wall model open source: https://doi.org/10.4121/4fd90d71-ffd9-4db2-a358-8576f5b19a32","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:9a149309-2339-40c5-9151-032d70b91dbe","http://resolver.tudelft.nl/uuid:9a149309-2339-40c5-9151-032d70b91dbe","Engineering and integration of pathways for anaerobic redox-cofactor balancing in yeast","van Aalst, A.C.A. (TU Delft BT/Industriele Microbiologie)","Pronk, J.T. (promotor); Daran, J.G. (promotor); Delft University of Technology (degree granting institution)","2023","The production of ethanol by the yeast Saccharomyces cerevisiae remains the process in industrial biotechnology with the largest product volume (ca. 100 million litres annually in 2022). Carbon losses occur due to the formation of biomass and glycerol, which can account for at least 8% of the product. Under anaerobic conditions, formation of yeast biomass and glycerol are coupled via redox-cofactor balances, as a net generation of NADH during biomass formation needs to be compensated by NADH-dependent formation of glycerol from sugar. This thesis discusses redox-engineering strategies for maximizing ethanol yields on substrate.","Redox engineering; Ethanol production; Saccharomyces cerevisiae; co-culture; Metabolic engineering; anaerobic fermentation; Electrons; industrial biotechnology","en","doctoral thesis","","978-94-6483-352-2","","","application external","","","","","","BT/Industriele Microbiologie","","",""
"uuid:59ee63bb-6f26-468f-8001-0ecffd3e8cc5","http://resolver.tudelft.nl/uuid:59ee63bb-6f26-468f-8001-0ecffd3e8cc5","Productive Failure Pedagogy in Engineering Mechanics","Persaud, S.M. (TU Delft Design for Sustainability); Flipsen, Bas (TU Delft Circular Product Design)","Buck, Lyndon (editor); Grierson, Hilary (editor); Bohemia, Erik (editor)","2023","In September 2021, the faculty of Industrial Design Engineering (IDE) introduced a revamped bachelor's program that emphasizes design for higher complexity, teacher as a coach, and autonomous learning. The program includes Understanding Product Engineering (UPE), which teaches first-year design students about product embodiment, manufacturing, and mechanics of materials. However, the traditional approach of teaching engineering using direct instructions and problem-based learning was ineffective, as students failed to apply the engineering knowledge in their capstone design projects.
To address this issue and promote autonomous learning, the Productive Failure (PF) pedagogical framework was introduced as the main pedagogical framework in UPE. However, the general approach of the PF pedagogy as described by Kapur, lacked a translation into an effective design of the workshops. To address this, this paper proposes a hands-on model based on constructive alignment, where learning objectives, activities, and assessment are designed side-by-side. This paper presents our didactical model, which was developed in an agile way during the second run of UPE. The hands-on model proposed aids in applying the PF pedagogy in engineering courses and consists of a method to develop workshop assignments and a didactical approach to guide and coach students through the workshop process.","autonomous learning; productive failure; direct instruction; product engineering; engineering; mechanics","en","conference paper","The Design Society, Institution of Engineering Designers","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-07","","","Design for Sustainability","","",""
"uuid:a5c27498-55c7-4edb-b7b8-3f3ccf7b77c7","http://resolver.tudelft.nl/uuid:a5c27498-55c7-4edb-b7b8-3f3ccf7b77c7","Mass transfer and flooding phenomena in carbon dioxide electrolyzers","Baumgartner, L.M. (TU Delft ChemE/Transport Phenomena)","Vermaas, D.A. (promotor); Kleijn, C.R. (promotor); Delft University of Technology (degree granting institution)","2023","Electrochemical carbon dioxide reduction is a potential pathway to the sustainable production of hydrocarbon fuels and chemicals. This thesis explores the material science and reactor engineering of carbon dioxide electrolyzers.","CO2 Reduction; Electrochemical Engineering; Electrochemistry; Gas diffusion electrode; Bipolar membrane; pH imaging","en","doctoral thesis","","978-94-93330-16-0","","","","","","","","","ChemE/Transport Phenomena","","",""
"uuid:0f61f871-7c9c-47fc-a542-10883fb2d4de","http://resolver.tudelft.nl/uuid:0f61f871-7c9c-47fc-a542-10883fb2d4de","Miniature sensorized platform for engineered heart tissues","Dostanic, M. (TU Delft Microelectronics; TU Delft Electronic Components, Technology and Materials)","Sarro, Pasqualina M (promotor); Mastrangeli, Massimo (copromotor); Delft University of Technology (degree granting institution)","2023","The high death toll of cardiovascular diseases worldwide and the lack of effective treatments for them are the main motivation for developing alternative and more efficient models for cardiac drug development and disease research. The missing link between current laboratory research on static in vitro and animal models and the clinical stage research on human patients could be created using the rapidly emerging Organ-on-Chip (OoC) technology. Themicrophysiological models developed within OoC research combine devices made of biocompatible, soft materials and human-origin organ-specific cell types, which are then exposed to flow, chemical, electrical or biomechanical stimuli.
Modeling a human cardiac in vivo environment in an artificial model represents quite a challenge from several aspects. First, cardiac tissue in vivo is exposed to a strong coupling between different biomechanical and electrical stimuli that need to be faithfully captured by an in vitro model. Furthermore, such an in vitro model should recapitulate the complexity of cell-cell and cell-extracellular matrix (ECM) interactions between different cardiac cell types, while obtaining physiologically relevant responses. This thesis addresses the first challenge, in an attempt to engineer a dynamic, artificial microenvironment, suitable for the growth, monitoring, and stimulation of hiPSC-based engineered cardiac tissues (EHTs).....","Engineered heart tissue; Heart-on-chip; Organ-on-chip; Microfabrication; Polymer processing","en","doctoral thesis","","","","","","","","","","Microelectronics","Electronic Components, Technology and Materials","","",""
"uuid:a4d2f3d3-74bc-4dcd-9e5a-71deb5f74a38","http://resolver.tudelft.nl/uuid:a4d2f3d3-74bc-4dcd-9e5a-71deb5f74a38","Extrusion-based 3D printing of biodegradable porous iron for bone substitution","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics)","Zadpoor, A.A. (promotor); Zhou, J. (promotor); Apachitei, I. (copromotor); Delft University of Technology (degree granting institution)","2023","The treatment of large bone injuries continues to be challenging partially due to the limited quantity and quality of bone-replacing materials. Iron (Fe) and its alloys have been developed as a group of load-bearing biomaterials. Recent advances in additive manufacturing (AM) have enhanced the potential of Fe-based biomaterials as biodegradable bone substitutes. Firstly, AM Fe-based implants can now be personalized to exactly match the geometry of bony defects. Secondly, AM Fe-based implants with macro- and micro-scale porosities can mimic the mechanical properties of the native bony tissue. The mechanical properties can also be tuned to sustain over the biodegradation period until the new bone tissue takes over their biomechanical function. Finally, AM offers a pathway for in situ or ex situ alloying as well as for other types of multi-material printing to achieve multiple functionalities, such as paramagnetic properties, high rates of biodegradation, and, most importantly, bioactivity (e.g., to induce the osteogenic differentiation of stem cells or to ward off implant-associated infections). This thesis contributes to designing biodegradable Fe-based scaffolds material configurations and developing associated fabrication technology with a focus placed on achieving an appropriate biodegradation rate, paramagnetic behavior, mimicking trabecular bone mechanical properties, and osteogenic all at once.","extrusion-based 3D printing; multi-material additive manufacturing; iiron; iron-manganese alloy; iron-akermanite composite; iron-manganese-akermanite composite; Biodegradable; porous; biomaterial; scaffolds; bone tissue engineering","en","doctoral thesis","","978-94-6384-416-1","","","","","","2023-04-30","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:0e98bb62-5518-4c59-9f6a-b845b8a71997","http://resolver.tudelft.nl/uuid:0e98bb62-5518-4c59-9f6a-b845b8a71997","Thermoelastic Stability of Deployable Space Telescopes","Villalba, Víctor (TU Delft Space Systems Egineering)","Gill, E.K.A. (promotor); Kuiper, J.M. (copromotor); Delft University of Technology (degree granting institution)","2023","Imagery collected from space provides very useful information about our planet. Today there are many Earth Observation satellites in orbit which allow us to collect information which is used for environmental monitoring, response to catastrophes, surveillance and security, urban planning, economic analysis and many other applications. Thus, there is a drive to improve the quality of this imagery, such as its resolution and the frequency with which it can be collected. The quantity of pictures taken will be increased by launching more systems, the quality of the pictures depends, amongst other factors, on the system’s physical size. To serve those needs, bigger telescopes have to be launchedmore often.....","thermoelastics; deployable space telescopes; piezoelectric actuators; compliant mechanisms; mechanical design; systems engineering","en","doctoral thesis","","978-94-6458-915-3","","","","","","","","","Space Systems Egineering","","",""
"uuid:f0393396-0044-4cc4-8d44-68950eeaade5","http://resolver.tudelft.nl/uuid:f0393396-0044-4cc4-8d44-68950eeaade5","Single and Multi-objective Test Cases Prioritization for Self-driving Cars in Virtual Environments","Birchler, Christian (Zurich University of Applied Science (ZHAW)); Khatiri, Sajad (Zurich University of Applied Science (ZHAW)); Derakhshanfar, P. (TU Delft Software Engineering); Panichella, Sebastiano (Zurich University of Applied Science (ZHAW)); Panichella, A. (TU Delft Software Engineering)","","2023","Testing with simulation environments helps to identify critical failing scenarios for self-driving cars (SDCs). Simulation-based tests are safer than in-field operational tests and allow detecting software defects before deployment. However, these tests are very expensive and are too many to be run frequently within limited time constraints.In this article, we investigate test case prioritization techniques to increase the ability to detect SDC regression faults with virtual tests earlier. Our approach, called SDC-Prioritizer, prioritizes virtual tests for SDCs according to static features of the roads we designed to be used within the driving scenarios. These features can be collected without running the tests, which means that they do not require past execution results. We introduce two evolutionary approaches to prioritize the test cases using diversity metrics (black-box heuristics) computed on these static features. These two approaches, called SO-SDC-Prioritizer and MO-SDC-Prioritizer, use single-objective and multi-objective genetic algorithms (GA), respectively, to find trade-offs between executing the less expensive tests and the most diverse test cases earlier.Our empirical study conducted in the SDC domain shows that MO-SDC-Prioritizer significantly (P- value <=0.1e-10) improves the ability to detect safety-critical failures at the same level of execution time compared to baselines: random and greedy-based test case orderings. Besides, our study indicates that multi-objective meta-heuristics outperform single-objective approaches when prioritizing simulation-based tests for SDCs.MO-SDC-Prioritizer prioritizes test cases with a large improvement in fault detection while its overhead (up to 0.45% of the test execution cost) is negligible.","Autonomous Systems; Software Simulation; Test Case Prioritization; Self-driving cars; Search-based Software Engineering; Software Testing; Evolutionary computation","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:c6e6cf2c-de3d-439c-bb8e-8b176fcb3b58","http://resolver.tudelft.nl/uuid:c6e6cf2c-de3d-439c-bb8e-8b176fcb3b58","Generating Class-Level Integration Tests Using Call Site Information","Derakhshanfar, P. (TU Delft Software Engineering); Devroey, Xavier (University of Namur); Panichella, A. (TU Delft Software Engineering); Zaidman, A.E. (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology)","","2023","Search-based approaches have been used in the literature to automate the process of creating unit test cases. However, related work has shown that generated tests with high code coverage could be ineffective, i.e., they may not detect all faults or kill all injected mutants. In this paper, we propose Cling, an integration-level test case generation approach that exploits how a pair of classes, the caller and the callee, interact with each other through method calls. In particular, Cling generates integration-level test cases that maximize the Coupled Branches Criterion (CBC). Coupled branches are pairs of branches containing a branch of the caller and a branch of the callee such that an integration test that exercises the former also exercises the latter. CBC is a novel integration-level coverage criterion, measuring the degree to which a test suite exercises the interactions between a caller and its callee classes. We implemented Cling and evaluated the approach on 140 pairs of classes from five different open-source Java projects. Our results show that (1) Cling generates test suites with high CBC coverage, thanks to the definition of the test suite generation as a many-objectives problem where each couple of branches is an independent objective; (2) such generated suites trigger different class interactions and can kill on average 7.7% (with a maximum of 50%) of mutants that are not detected by tests generated randomly or at the unit level; (3) Cling can detect integration faults coming from wrong assumptions about the usage of the callee class (25 for our subject systems) that remain undetected when using automatically generated random and unit-level test suites.","search-based software engineering; Class Integration testing; coverage criteria; evolutionary algorithms; Many-objective optimization","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-11-01","","Software Technology","Software Engineering","","",""
"uuid:673283a0-e73e-408d-813a-8f513f303e30","http://resolver.tudelft.nl/uuid:673283a0-e73e-408d-813a-8f513f303e30","Highly reproducible tissue positioning with tapered pillar design in engineered heart tissue platforms","Dostanic, M. (TU Delft Microelectronics; Leiden University Medical Center); Windt, Laura (Leiden University Medical Center); Wiendels, Maury (Leiden University Medical Center); van Meer, Berend J. (Leiden University Medical Center); Mummery, Christine L. (Leiden University Medical Center; University of Twente); Sarro, Pasqualina M (TU Delft Electronic Components, Technology and Materials); Mastrangeli, Massimo (TU Delft Electronic Components, Technology and Materials)","","2023","We present a novel design of elastic micropillars for tissue self-assembly in engineered heart tissue (EHT) platforms. The innovative tapered profile confines reproducibly the tissue position along the main micropillar axis, increasing the accuracy of tissue contraction force measurement. Polydimethylsiloxane-based pillars were designed and fabricated by wafer-level molding in an hourglass shape, with symmetric tapering producing a restriction for tissue movement in the middle of the pillars’ length. Confinement efficacy of the new geometry was validated by comparing the tissue performance in straight versus tapered (75° or 80° tapering angle) micropillars. While in all three cases compact tissues formed successfully, for both tapered designs the functionality assays evidenced yield increase from 15% to 100%, higher spatial tissue confinement, and correspondingly higher accuracy and smaller dispersion in measurements of tissue contraction force.","engineered heart tissue; heart-on-chip; organ-on-chip; microfabrication","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-01","","Microelectronics","Electronic Components, Technology and Materials","","",""
"uuid:76de8b6c-97d8-4020-b1ef-30dd182d9bdc","http://resolver.tudelft.nl/uuid:76de8b6c-97d8-4020-b1ef-30dd182d9bdc","The Use of Digital Peer Assessment in Higher Education: An Umbrella Review of Literature","van Helden, G. (TU Delft Space Systems Egineering; Leiden-Delft-Erasmus Centre for Education and Learning (LDE-CEL)); van der Werf, V. (Leiden-Delft-Erasmus Centre for Education and Learning (LDE-CEL); Universiteit Leiden); Saunders-Smits, Gillian (TU Delft Robot Dynamics; Leiden-Delft-Erasmus Centre for Education and Learning (LDE-CEL)); Specht, M.M. (TU Delft Web Information Systems; Leiden-Delft-Erasmus Centre for Education and Learning (LDE-CEL); Universiteit Leiden)","","2023","Increasing student numbers in higher education, particularly in engineering and computer science, make it difficult for motivated lecturers to continue engaging in active teaching methods such as Flipped Classrooms and Work-Based Learning. In these settings, digital Peer Assessment can be one approach to provide effective and scalable feedback. In Peer Assessment, students assess each other’s performance whilst gaining useful reflection and judgment skills at the same time. This umbrella review of 14 review papers on the use of (digital) Peer Assessment in education provides a comprehensive overview of design choices and their consequences open to educational practitioners wishing to implement digital Peer Assessment in their courses, the type of tooling available and the possible effects of these choices on the learning outcomes as well as potential pitfalls and challenges when implementing Peer Assessment. The paper will inform and assist educators in finding or developing a tool that fits their needs.","Digital education; educational technology; engineering education; peer assessment","en","review","","","","","","","","","","","Space Systems Egineering","","",""
"uuid:08c2f076-b8d0-4c44-931d-7dc922471367","http://resolver.tudelft.nl/uuid:08c2f076-b8d0-4c44-931d-7dc922471367","Analyzing Sustainability Awareness and Professional Ethics of Civil Engineering Bachelor’s Degree Students","Mares Nasarre, P. (TU Delft Hydraulic Structures and Flood Risk); Martínez-Ibáñez, Víctor (Universitat Politécnica de Valencia); Sanz-Benlloch, Amalia (Universitat Politécnica de Valencia)","","2023","Teaching sustainability and ethics to engineering students is a challenging but necessary task that has been increasingly investigated during the last few years. In this research, a systematic method to identify the level of awareness in students about sustainability and ethics is developed. Here, it is applied to students studying the Civil Engineering bachelor’s degree at the School of Civil Engineering of Universitat Politècnica de València (UPV), though this method is potentially applicable to equivalent ABET and EUR-ACE accredited bachelor’s degrees. A survey was performed, and data was analyzed using Analytical hierarchical process technique; this technique determines the relative importance of each criterion, as well as the consistency of the emitted judgements, in an objective manner. These results allowed to discover that students do not have a robust opinion related to sustainability and ethics, except those students with previous experience in the construction sector. Environmental and social dimensions of sustainability and ethics were identified as the main focuses to emphasize in the civil engineering curriculum. Finally, actions to boot these principles are also proposed; potential courses where sustainability and ethics concepts could be explicitly included were selected and the inclusion of an environmental budget in the bachelor thesis was recommended, among others suggestions.","education; sustainability; professional ethics; civil engineering; sustainable development goals; professional skills","en","journal article","","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:173c2590-22ac-483b-bad3-d22546429e1c","http://resolver.tudelft.nl/uuid:173c2590-22ac-483b-bad3-d22546429e1c","Preloading of four-legged jack-ups in clay: Geotechnical time effects and fulfilment of preloading criteria","Sonnema, Wouter (Heerema Marine Contractors); Brinkman, Sanne (Van Oord); Brinkgreve, R.B.J. (TU Delft Geo-engineering); Pisano, F. (TU Delft Geo-engineering)","","2023","Presented here is a numerical study on the preloading of four-legged jack-ups, such as those commonly employed in the construction of offshore wind farms. The need for reducing jack-up installation time is particularly felt within the offshore industry, especially when multiple preloading cycles are necessary in clayey soils to fulfil given preloading criteria. This is due to clays experiencing delayed deformations, causing load redistribution among all legs while the ideal situation of steady preload on all spudcans is pursued. This work employs three-dimensional finite element (3D FE) modelling to analyse the preloading performance of a reference jack-up vessel in clayey soils using a wished-in-place (WIP) approach. Detailed modelling of time effects due to soil consolidation and viscosity is introduced, with some emphasis on how to derive material parameters from typical site investigation and laboratory soil data. The results of specific parametric studies are presented to support the suitability of the adopted analysis approach, also with regard to the adoption of alternative preloading procedures. The constitutive modelling of time-dependent clay’s behaviour is shown to play a crucial role in the considered framework, and will require further research for 3D FE modelling to provide reliable quantitative support to real wind farm installation projects.","Jack-up; Spudcan; Preloading; Clay; Finite elements; Offshore engineering","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:085b263c-1880-49e9-9022-c4e156990da2","http://resolver.tudelft.nl/uuid:085b263c-1880-49e9-9022-c4e156990da2","Searching for Quality: Genetic Algorithms and Metamorphic Testing for Software Engineering ML","Applis, L.H. (TU Delft Software Engineering); Panichella, A. (TU Delft Software Engineering); Marang, R.J. (Student TU Delft)","","2023","More machine learning (ML) models are introduced to the field of Software Engineering (SE) and reached a stage of maturity to be considered for real-world use; But the real world is complex, and testing these models lacks often in explainability, feasibility and computational capacities. Existing research introduced meta-morphic testing to gain additional insights and certainty about the model, by applying semantic-preserving changes to input-data while observing model-output. As this is currently done at random places, it can lead to potentially unrealistic datapoints and high computational costs. With this work, we introduce genetic search as an aid for metamorphic testing in SE ML. Exploiting the delta in output as a fitness function, the evolutionary intelligence optimizes the transformations to produce higher deltas with less changes. We perform a case study minimizing F1 and MRR for Code2Vec on a representative sample from java-small with both genetic and random search. Our results show that within the same amount of time, genetic search was able to achieve a decrease of 10% in F1 while random search produced 3% drop.","Search-based software engineering; Evolutionary algorithms; Metamorphic testing; Machine Learning","en","conference paper","ACM/IEEE","","","","","","","","","","Software Engineering","","",""
"uuid:ede25e1d-fa1e-4091-8f8d-3874c783d2a9","http://resolver.tudelft.nl/uuid:ede25e1d-fa1e-4091-8f8d-3874c783d2a9","Extending Source Code Pre-Trained Language Models to Summarise Decompiled Binaries","Al-Kaswan, A. (TU Delft Software Engineering); Ahmed, Toufique (University of California); Izadi, M. (TU Delft Software Engineering); Sawant, Anand Ashok (University of California); Devanbu, Premkumar (University of California); van Deursen, A. (TU Delft Software Technology)","Ceballos, Cristina (editor)","2023","Binary reverse engineering is used to understand and analyse programs for which the source code is unavailable. Decompilers can help, transforming opaque binaries into a more readable source code-like representation. Still, reverse engineering is difficult and costly, involving considering effort in labelling code with helpful summaries. While the automated summarisation of decompiled code can help reverse engineers understand and analyse binaries, current work mainly focuses on summarising source code, and no suitable dataset exists for this task. In this work, we extend large pre-trained language models of source code to summarise de-compiled binary functions. Further-more, we investigate the impact of input and data properties on the performance of such models. Our approach consists of two main components; the data and the model. We first build CAPYBARA, a dataset of 214K decompiled function-documentation pairs across various compiler optimisations. We extend CAPYBARA further by removing identifiers, and deduplicating the data. Next, we fine-tune the CodeT5 base model with CAPYBARA to create BinT5. BinT5 achieves the state-of-the-art BLEU-4 score of 60.83, 58.82 and, 44.21 for summarising source, decompiled, and obfuscated decompiled code, respectively. This indicates that these models can be extended to decompiled binaries successfully. Finally, we found that the performance of BinT5 is not heavily dependent on the dataset size and compiler optimisation level. We recommend future research to further investigate transferring knowledge when working with less expressive input formats such as stripped binaries.","Decompilation; Binary; Reverse Engineering; Summarization; Deep Learning; Pre-trained Language Models; CodeT5; Transformers","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-11-15","","Software Technology","Software Engineering","","",""
"uuid:989cc593-ce94-44c2-aac6-14bf6bdc743e","http://resolver.tudelft.nl/uuid:989cc593-ce94-44c2-aac6-14bf6bdc743e","A resilience assessment framework for complex engineered systems using graphical evaluation and review technique (GERT)","Geng, S. (TU Delft Safety and Security Science; Nanjing University of Aeronautics and Astronautics); Yang, M. (TU Delft Safety and Security Science; Universiti Teknologi Malaysia); Mitici, Mihaela (Universiteit Utrecht); Liu, Sifeng (Nanjing University of Aeronautics and Astronautics)","","2023","System resilience characterizes the capability of maintaining the required functionality under disruptions, which is of great significance in evaluating the productivity and safety of complex engineered systems. Although most studies conduct resilience assessment from qualitative and quantitative perspectives, system functionality that reflects functional requirements for complex engineered systems needs to be elaborated. In addition, given that complex engineered systems achieve dynamic performance during disruptions, measuring the actual performance under uncertainty is imperative. To this end, this paper develops a quantitative framework to assess the resilience of complex engineered systems. The developed framework comprises three phases, functionality analysis, performance evaluation, and resilience assessment. Firstly, system functionality is analyzed using a functional tree illustrating the relationship between functions. The overall objective, primary functions, and sub-functions are identified according to task requirements. Secondly, system performance is quantified considering uncertain factors through Graphical Evaluation and Review Technique (GERT). Probabilistic branches and network logic are employed to represent the implementation of various functions. Finally, resilience assessment is carried out from the perspectives of anticipation, absorption, adaptation, and restoration abilities. A case study on the satellite network shows the effectiveness of the developed framework. The developed framework determines system functionality based on task requirements, evaluates system performance with limited information, and accurately assesses system resilience.","Complex engineered systems; Functionality analysis; Performance evaluation; Resilience assessment; Risk management","en","journal article","","","","","","","","","","","Safety and Security Science","","",""
"uuid:a6372484-3549-4d47-b9ba-8a55a138887b","http://resolver.tudelft.nl/uuid:a6372484-3549-4d47-b9ba-8a55a138887b","Semicentennial Response of a Bifurcation Region in an Engineered River to Peak Flows and Human Interventions","Chowdhury, M. Kifayath (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Blom, A. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Ylla Arbos, C. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Verbeek, Merel C. (Rijkswaterstaat); Schropp, Max H.I. (Rijkswaterstaat); Schielen, R.M.J. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Rijkswaterstaat)","","2023","A bifurcation in an engineered river system (i.e., fixed planform and width) has fewer degrees of freedom in its response to interventions and natural changes than a natural bifurcation system. Our objective is to provide insight into how a bifurcation in an engineered river responds to peak flows and human interventions. To this end, we analyze the change in hydraulics, bed level, and bed surface grain size in the region of two bifurcations in the upper Rhine delta in the Netherlands over the last century. We show that, over the last two decades, the water discharge in one bifurcate (the Waal branch) has steadily increased at the expense of the other. This gradual increase in the water discharge of the first branch is associated with its erosion rate being larger than the other branch. The quick succession of two or three peak flow events (1993, 1995, and 1998) caused rapid sediment deposition over the upstream part of the bifurcate that has gradually lost discharge, which seems to have triggered the slow change in flow partitioning.","River bifurcation; Rhine River; Netherlands; Flow partitioning; Peak flow; Engineered Rivers; Tipping point; Gravel bed rivers; Upper Rhine delta; Flood","en","journal article","","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:9e0166d7-4ded-4b09-b255-debaa0577a6a","http://resolver.tudelft.nl/uuid:9e0166d7-4ded-4b09-b255-debaa0577a6a","Practical Product Development Challenges","Ashruf, CMA (TU Delft Electronic Instrumentation)","","2023","Despite the many product development techniques available today, manufacturers under pressure to reduce time to market while keeping up with stricter regulatory demands are struggling more than ever with their product development processes. Here, I list a selection of problems and challenges frequently encountered in my consulting practice and checked with literature, as well as practical recommendations for improvement. While in specific situations some project management techniques prove better suited than others, overall product development success seems more dependent on the organization's willingness and ability to learn and adapt rather than on the specific technique chosen.","Companies; empowerment; implementation methodologies & project management; Industries; management of innovation; management of scientists and engineers; Product development; product innovations; project and R&D management; project success factors; Standards organizations; success factors in product development; Technological innovation; Training; Weaving","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-12-04","","","Electronic Instrumentation","","",""
"uuid:0a020d5d-1b38-4102-ab14-de2f4efd414d","http://resolver.tudelft.nl/uuid:0a020d5d-1b38-4102-ab14-de2f4efd414d","How Engineers Can Care from a Distance: Promoting Moral Sensitivity in Engineering Ethics Education","van Grunsven, J.B. (TU Delft Ethics & Philosophy of Technology); Marin, L. (TU Delft Ethics & Philosophy of Technology); Stone, T.W. (TU Delft Ethics & Philosophy of Technology); Doorn, N. (TU Delft Ethics & Philosophy of Technology); Roeser, S. (TU Delft Values Technology and Innovation)","Miller, Glenn (editor); Mateus Jerónimo, Helena (editor); Zhu, Qin (editor)","2023","Moral (or ethical) sensitivity is widely viewed as a foundational learning goal in engineering ethics education. We have argued in this paper is that this view of moral sensitivity cannot be readily transported from the nursing context to the engineering context on the basis of a care-analogy. The particularized care characteristic of the nursing context is decisively different from the generalized and universalized forms of care characteristic of the engineering context. Through a focus on care and maintenance, the engineering student’s moral sensitivity can be refined, opening up a perceptual awakening and affectivity towards the complex nature of the engineer’s Other. This awakening is in part promoted through an understanding of the ideology of neutrality as a moment in the history engineering. Becoming aware of this ideology as an ideology can then be seen as an activity of dividing loyalties that allows for a reflexive and critical view of the biases and presuppositions inherited within the world of engineering. This process of deepening the engineering student’s moral sensitivity is perhaps as much a process of the student becoming aware of her professional world, how it shapes her understanding of herself, and what it means to be a good engineer.","Philosophy of engineering; Engineering education; philosophy of technology; Moral sensitivity","en","book chapter","Rowman & Littlefield","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-01","","Values Technology and Innovation","Ethics & Philosophy of Technology","","",""
"uuid:c898a66e-b760-4528-aaa5-e82212694e09","http://resolver.tudelft.nl/uuid:c898a66e-b760-4528-aaa5-e82212694e09","Influence of fiber orientation on the mechanical responses of engineering cementitious composite (ECC) under various loading conditions","Tawfek, Abdullah M. (Shandong University; Sana'a University); Ge, Zhi (Shandong University); Yuan, Huaqiang (Shandong University); Zhang, Ning (Tsinghua University); Zhang, Hongzhi (Shandong University); Ling, Yifeng (Shandong University); Guan, Yanhua (Shandong University); Šavija, B. (TU Delft Materials and Environment)","","2023","The mechanical performance of engineered cementitious composite (ECC) depends greatly on fiber orientation and distribution. In this paper, the effect of fiber orientation on ECC's mechanical properties was investigated using two different casting methods: a flow-induced casting was used to enhance the fiber orientation within ECC mixture and compared with the conventional casting. The fiber orientation was quantified using scanning electron microscope (SEM) and image processing. Mechanical tests on the specimens with various fiber orientations were performed. The failure processes of ECC specimens under compression and tensile tests were analyzed using digital image correlation (DIC) technique. The proposed flow-induced casting enhanced the fiber alignment in the flow direction. Consequently, ECC's mechanical properties were significantly improved with more finer cracks under uniaxial loading. In conclusion, the proposed flow-induced casting can be adopted as an effective approach to improve fiber bridging efficiency in ECC.","Engineering cementitious composite; Fiber orientation; Mechanical behavior; Digital image correlation; Crack width","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Materials and Environment","","",""
"uuid:3bf9e596-e126-4cdf-b4d4-55f17cd705d9","http://resolver.tudelft.nl/uuid:3bf9e596-e126-4cdf-b4d4-55f17cd705d9","Data Lakes: A Survey of Functions and Systems","Hai, R. (TU Delft Web Information Systems); Koutras, C. (TU Delft Web Information Systems); Quix, Christoph (Hochschule Niederrhein); Jarke, Matthias (Fraunhofer Institute for Applied Information Technology FIT)","","2023","Data lakes are becoming increasingly prevalent for Big Data management and data analytics. In contrast to traditional 'schema-on-write' approaches such as data warehouses, data lakes are repositories storing raw data in its original formats and providing a common access interface. Despite the strong interest raised from both academia and industry, there is a large body of ambiguity regarding the definition, functions and available technologies for data lakes. A complete, coherent picture of data lake challenges and solutions is still missing. This survey reviews the development, architectures, and systems of data lakes. We provide a comprehensive overview of research questions for designing and building data lakes. We classify the existing approaches and systems based on their provided functions for data lakes, which makes this survey a useful technical reference for designing, implementing and deploying data lakes. We hope that the thorough comparison of existing solutions and the discussion of open research challenges in this survey will motivate the future development of data lake research and practice.","Big Data applications; Data discovery; Data lake; Lakes; Maintenance engineering; Memory; Metadata; Metadata management; Proposals; Semantics","en","journal article","","","","","","","","","","","Web Information Systems","","",""
"uuid:ef07dc0e-37f4-4b1a-9e65-7bc55c6db39b","http://resolver.tudelft.nl/uuid:ef07dc0e-37f4-4b1a-9e65-7bc55c6db39b","Functional Synthetic Biology","Aldulijan, Ibrahim (Stevens Institute of Technology); Beal, Jacob (Intelligent Software & Systems, Raytheon BBN Technologies, Cambridge); Billerbeck, Sonja (Rijksuniversiteit Groningen); Bouffard, Jeff (Concordia University); Chambonnier, Gaël (Massachusetts Institute of Technology); Ntelkis, Nikolaos (Universiteit Gent); Guerreiro, Isaac (iGEM Foundation, Cambridge); Holub, M. (TU Delft BN/Cees Dekker Lab); Ross, Paul (BioStrat Marketing, Boynton Beach)","","2023","Synthetic biologists have made great progress over the past decade in developing methods for modular assembly of genetic sequences and in engineering biological systems with a wide variety of functions in various contexts and organisms. However, current paradigms in the field entangle sequence and functionality in a manner that makes abstraction difficult, reduces engineering flexibility and impairs predictability and design reuse. Functional Synthetic Biology aims to overcome these impediments by focusing the design of biological systems on function, rather than on sequence. This reorientation will decouple the engineering of biological devices from the specifics of how those devices are put to use, requiring both conceptual and organizational change, as well as supporting software tooling. Realizing this vision of Functional Synthetic Biology will allow more flexibility in how devices are used, more opportunity for reuse of devices and data, improvements in predictability and reductions in technical risk and cost.","Collaboration; Design; Engineering; Reproducibility; Synthetic Biology","en","review","","","","","","","","","","","BN/Cees Dekker Lab","","",""
"uuid:7cb6ce24-c285-42e8-a24e-acdd5333559f","http://resolver.tudelft.nl/uuid:7cb6ce24-c285-42e8-a24e-acdd5333559f","Cities of the Future: Towards Sustainable City Economies","Heurkens, E.W.T.M. (TU Delft Urban Development Management)","Cavallo, Roberto (editor); Kuijper, Joran (editor); Harteveld, Maurice (editor); Carreiro Matias, Marcelo (editor); Ulkü, Mesut (editor); Drašković, Sonja (editor)","2023","It goes without saying that cities of tomorrow face numerous challenges that will change their appearance drastically. We only now begin to notice a gradual change towards climate-adaptive cities, inner-city renewable energy production, and more healthy urban environments by re-naturing our public realm and buildings as well as accommodating societal initiatives within urban neighbourhoods. Such sustainability transitions within the built environment unfold in front of our eyes and are as appealing as urgently needed to make our cities liveable and thrive. Nonetheless, the physical transformations that come with such changes are also driven by economic factors and conditioned by financial aspects less visible and tangible. Yet, unquestionably, they help drive and support such sustainability transitions and built environment transformations. So how can we conceive of the economic factors shaping the city of the future?","city; future; education; engineering; graduation lab; built environment; architecture; urban design","en","book chapter","TU Delft OPEN","","","","","","","","","","Urban Development Management","","",""
"uuid:0c9894b0-86d1-48a5-9b84-47a4128afe5c","http://resolver.tudelft.nl/uuid:0c9894b0-86d1-48a5-9b84-47a4128afe5c","Cities of the Future: Control in Times of Acceleration","Muñoz Sanz, V. (TU Delft Urban Design)","Cavallo, Roberto (editor); Kuijper, Joran (editor); Harteveld, Maurice (editor); Carreiro Matias, Marcelo (editor); Ulkü, Mesut (editor); Drašković, Sonja (editor)","2023","'The architect who proposes to run with technology knows now that he [sic] will be in fast company, and that, in order to keep up, he may have to emulate the Futurists and discard his whole cultural load, including the professional garments by which he is recognized as an architect. If, on the other hand, he decides not to do this, he may find that a technological culture has decided to go on without him.'
These cautionary, and still relevant, words by Rayner Banham in his book 'Theory and Design in the First Machine Age' are very telling of the key challenge of dealing with the implications of technology in our cities. [...]","city; future; education; engineering; graduation lab; built environment; architecture; urban design; data","en","book chapter","TU Delft OPEN","","","","","","","","","","Urban Design","","",""
"uuid:b7d90b23-00c0-4707-8876-df19efd9dc89","http://resolver.tudelft.nl/uuid:b7d90b23-00c0-4707-8876-df19efd9dc89","Cities of the Future: On Nature and the Grammar of Design","Cannatella, D. (TU Delft Urban Data Science)","Cavallo, Roberto (editor); Kuijper, Joran (editor); Harteveld, Maurice (editor); Carreiro Matias, Marcelo (editor); Ulkü, Mesut (editor); Drašković, Sonja (editor)","2023","In his book, 'The sense of style', the cognitive scientist Steven Pinker argues that the categories of grammar reflect the four building blocks of thought: time, space, causality, and matter. Coincidentally, these building blocks are the same ones that dictate the grammar of spatial design. In them being absolute categories, they describe well the way architects, designers, planners and landscape architects perceive, investigate and intervene in the reality around them.","city; future; education; engineering; graduation lab; built environment; architecture; urban design; landscape architecture","en","book chapter","TU Delft OPEN","","","","","","","","","","Urban Data Science","","",""
"uuid:bad96320-666c-4fc9-8804-2ec0d5cf41ab","http://resolver.tudelft.nl/uuid:bad96320-666c-4fc9-8804-2ec0d5cf41ab","Cities of the Future: A Mobile and Sustainable Society","Vleugel, J (TU Delft Transport and Planning)","Cavallo, Roberto (editor); Kuijper, Joran (editor); Harteveld, Maurice (editor); Carreiro Matias, Marcelo (editor); Ulkü, Mesut (editor); Drašković, Sonja (editor)","2023","My research career started with a publication about externalities of mass motorization. Academic researchers are producing an endless stream of paper. Unfortunately, only a few of these publications have practical relevance. Even if they do, their recommendations are frequently butchered, mitigated or ignored in the political arena. Such experience can even turn a born optimist into a pessimist.","city; future; education; engineering; graduation lab; built environment; architecture; urban design; sustainability","en","book chapter","TU Delft OPEN","","","","","","","","","","Transport and Planning","","",""
"uuid:dc8d5660-100f-486f-86d6-4c573d4109a4","http://resolver.tudelft.nl/uuid:dc8d5660-100f-486f-86d6-4c573d4109a4","From Requirements to Product: an MBSE Approach for the Digitalization of the Aircraft Design Process","Bruggeman, A.M.R.M. (TU Delft Flight Performance and Propulsion); la Rocca, G. (TU Delft Flight Performance and Propulsion)","","2023","During the aircraft conceptual design phase, many different design options need to be explored and compared in a short time frame. To speed up this process, efforts have been made in the past decades to digitalize parts of the design process, with a focus on the automation of the repetitive and non-creative tasks inherent to the iterative design process. Whilst many of the newly developed methodologies focus on specific parts of the design process, a holistic model-based design framework, incorporating the latest design technology developments, is lacking. To fill this gap, this paper presents the latest version of the Design and Engineering Engine (DEE) framework, originally proposed in the early 2000s and progressively matured through the experience of several international research collaborations. The DEE enables the setup and execution of Multidisciplinary Design Analysis and Optimization (MDAO) problems for aircraft (sub)systems, leveraging the automated, rule-based modeling capabilities offered by Knowledge-Based Engineering (KBE) and recent developments in the automatic formulation and integration of MDAO workflows. While the traditional MDAO process focuses on a given product architecture, the DEE allows also architectural design studies and makes use of Model-Based Systems Engineering (MBSE) principles to address the whole design process, from requirements modeling up to the automatic verification of the requirements. In practice, the DEE provides a single conceptual framework or template from which specific design framework instances can be formulated and executed, according to the user's needs. This paper describes the DEE architecture and its implementation concepts. Furthermore, it demonstrates the application of the DEE template to four different scenarios, ranging from a simple requirement verification study, up to the simultaneous synthesis and optimization of an aircraft system and its production process, including multiple system architecture options.","Model Based Systems Engineering; Multidisciplinary Design Optimization; Aircraft Design Process","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-04","","","Flight Performance and Propulsion","","",""
"uuid:1466a92f-6321-47fe-af57-879916a8a080","http://resolver.tudelft.nl/uuid:1466a92f-6321-47fe-af57-879916a8a080","Grammar-Based Evolutionary Fuzzing for JSON-RPC APIs","Veldkamp, L.S. (Student TU Delft); Olsthoorn, Mitchell (TU Delft Software Engineering); Panichella, A. (TU Delft Software Engineering)","","2023","Web Application Programming Interfaces (APIs) allow systems to be addressed programmatically and form the backbone of the internet. RESTful and RPC APIs are among the most common API architectures used. In the last decades, researchers have proposed various techniques for automated testing of RESTful APIs, however, to the best of the authors' knowledge there exists no work on testing JSON-RPC (one of the two data formats supported by RPC) APIs. To address this limitation, we propose a grammar-based evolutionary fuzzing approach for testing JSON-RPC APIs that uses a novel black-box heuristic. Specifically, we use a diversity-based fitness function based on hierarchical clustering to quantity the differences in API method responses. Our hypothesis is that responses that are unlike previously seen ones are an indication that new uncovered code paths are reached. We evaluate our approach on the XRP ledger, a large-scale industrial blockchain system that uses JSON-RPC APIs. Our results show that the proposed approach performs significantly better than the baseline (grammar-based fuzzer) and covers an additional 240 branches.","Search-based Software Engineering; Fuzzing; Test Case Generation; API Testing; Hierarchical Clustering","en","conference paper","IEEE / ACM","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-05","","","Software Engineering","","",""
"uuid:2da3155b-47d4-4eeb-a960-350cb7a0a3b9","http://resolver.tudelft.nl/uuid:2da3155b-47d4-4eeb-a960-350cb7a0a3b9","A Review on Non-destructive Evaluation of Civil Structures Using Magnetic Sensors","Eslamlou, A.D. (Iran University of Science and Technology); Ghaderiaram, A. (TU Delft Materials and Environment); Fotouhi, M. (TU Delft Materials and Environment); Schlangen, E. (TU Delft Materials and Environment)","Rizzo, Piervincenzo (editor); Milazzo, Alberto (editor)","2023","The growing demand towards life cycle sustainability has created a tremendous interest in non-destructive evaluation (NDE) to minimize manufacturing defects and waste, and to improve maintenance and extend service life. Applications of Magnetic Sensors (MSs) in NDE of civil engineering structures have become of great interest in recent years due to their non-contact data collection, and their high sensitivity under the influence of external stimuli such as strain, temperature, and humidity, to detect damage and deficiencies. There have been several advancements in MSs over the years for strain evaluation, corrosion monitoring, etc. based on the magnetic property changes. However, these MSs are at their nascent stages of development, and thus, there are several challenges that exist. This paper summarizes the recent advancements in MSs and their applications in civil engineering. Principle functions of different MSs are discussed, and their comparative characteristics are presented. The research challenges are highlighted and the roadmap towards high technology readiness level is discussed.","Civil engineering; Eddy Current; Hall effect sensor; Magnetic flux leakage; Magnetoresistve sensor; Non-destructive evaluation","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-12-22","","","Materials and Environment","","",""
"uuid:2ce06e5f-74ba-446f-bb70-597d32914aa6","http://resolver.tudelft.nl/uuid:2ce06e5f-74ba-446f-bb70-597d32914aa6","Searching for Reconnection: Environmental Challenges and Course Changes in Spatial Development Along Shanghai’s Shipping Channels","den Hartog, Harry (TU Delft Spatial Planning and Strategy; TU Delft History, Form & Aesthetics; Tongji University)","","2023","Waterways played a crucial role in the emergence of Shanghai as a cosmopolitan city and world port. Over the years the spatial and functional relationships between the city and ports and hinterland have been changing continuously. In Shanghai, like other port cities, almost all ports and related industries are placed out beyond the urban fringes, to form decentralized regional clusters, while former docklands are quickly transformed into attractive urban waterfronts. Simultaneously there is a growing physical and socio‐economic gap with the rural hinterland. During Shanghai’s brutal lockdown in Spring 2022, due to China’s rigid zero‐Covid policy, citizens were without food and other supplies while fully loaded ships were lined up waiting in the port. Also, deliveries from surrounding rural areas were temporarily halted. This article focuses on recent developments but is based on experiences in previous centuries from a long durée perspective. It elaborates on how the Yangtze River Delta urbanized along shipping channels and examines changing relationships between city and port, between urban and rural, and between man and nature. What role did shipping channels play and how to rebalance
various spatial claims: urban, rural, port interests, and environmental concerns?","ecological civilization; flood risk; hydraulic engineering; lockdown; long durée; port city; rural hinterland; shipping channel; spatial decentralization; urban delta","en","journal article","","","","","","","","","","","Spatial Planning and Strategy","","",""
"uuid:f5c2d38c-0bbe-4b2b-8108-1b77be19ff1a","http://resolver.tudelft.nl/uuid:f5c2d38c-0bbe-4b2b-8108-1b77be19ff1a","Structured Electronics Design: A Conceptual Approach to Amplifier Design, 3rd ed","Montagne, A.J.M. (TU Delft Electronics)","","2023","Many people consider analog electronic circuit design complex. This is because designers can achieve the desired performance of a circuit in many ways. Together, theoretical concepts, circuit topologies, electronic devices, their operating conditions, and the system's physical construction constitute an enormous design space in which it is easy to get lost. For this reason, analog electronics often is regarded as an art rather than a solid discipline.
Structured Electronics Design:
- Defines a step-by-step hierarchically organized design process.
- Is based on solid principles from systems engineering, physics, signal processing, control theory, and network theory.
- Provides a solid foundation for circuit design education and automation.
- Has been developed at the TU Delft since the 1980s.","electronics; circuit design; circuit topologies; systems engineering; signal processing; control theory","en","book","TU Delft OPEN Publishing","978-94-6366-712-8","","","","","","","","","Electronics","","",""
"uuid:3ddacf16-e93c-49c3-89aa-2090184ba4ff","http://resolver.tudelft.nl/uuid:3ddacf16-e93c-49c3-89aa-2090184ba4ff","Educational framework","Kuijper, J.A. (TU Delft Theory, Territories & Transitions)","Cavallo, Roberto (editor); Kuijper, Joran (editor); Harteveld, Maurice (editor); Carreiro Matias, Marcelo (editor); Ulkü, Mesut (editor); Drašković, Sonja (editor)","2023","Not only within the Faculty of Architecture and the Built Environment, but throughout Delft University of Technology, the City of the Future Graduation Lab proves to have a truly unique position. It is a laboratory where students are challenged to think beyond their own discipline, creating an interdisciplinary synergy between different fields of expertise in order to find solutions for the City of the Future.","City; Future; Multidisciplinarity; Design; Education; Engineering; Graduation Lab; Built Environment; Architecture; Urban Design; Management; Geomatics; Transport; Infrastructure; Logistics; Collaboration","en","book chapter","TU Delft OPEN Publishing","","","","","","","","","","Theory, Territories & Transitions","","",""
"uuid:e9309de8-82e8-4266-85a0-2436a0e40190","http://resolver.tudelft.nl/uuid:e9309de8-82e8-4266-85a0-2436a0e40190","Drone-racing champions outpaced by AI","de Croon, G.C.H.E. (TU Delft Control & Simulation)","","2023","","Engineering; Machine learning","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-01","","","Control & Simulation","","",""
"uuid:9d669e9e-ae4b-4de0-ab5c-9620352bc673","http://resolver.tudelft.nl/uuid:9d669e9e-ae4b-4de0-ab5c-9620352bc673","Quality Assurance Awareness in Open Source Software Projects on GitHub","Zaidman, A.E. (TU Delft Software Engineering); Khatami, Ali (TU Delft Software Engineering)","Moonen, Leon (editor); Newman, Christian (editor); Gorla, Alessandra (editor)","2023","Software engineers employ a variety of approaches to ensure the quality of software systems, including software testing, modern code review, automated static analysis, build automation, and continuous integration. To make effective decisions regarding quality assurance (QA), software engineers need to have an awareness of (1) the QA approaches that are in use in a project, and (2) how they are used. Through an exploratory, mixed-methods investigation we set out to better understand the awareness of software engineers in open-source software (OSS) development with regard to QA practices. This involved a largescale survey of 471 maintainers and contributors on GitHub. Our findings indicate that a high-level awareness among the respondents is common, but also that the respondents are less certain about how the practices are adopted; we further consider the perspective of both the contributor and the maintainer.","Software Quality Assurance; Open Source Software (OSS); Software Engineering; Software Testing; Code Review; Continuous Integration; Automation Workflows; GitHub","en","conference paper","IEEE Computer Society - Conference Publishing Services","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-07-01","","","Software Engineering","","",""
"uuid:49d3ba17-8623-429e-9efa-edc1aa090074","http://resolver.tudelft.nl/uuid:49d3ba17-8623-429e-9efa-edc1aa090074","Systemic risks and solar climate engineering research. Integrating technology ethics into the governance of systemic risks","Hofbauer, B. (TU Delft Ethics & Philosophy of Technology)","","2023","The paper explores how the framework of systemic risks can help govern the risks imposed through solar climate engineering research. The central argument is that a systemic perspective of risk is a useful tool for analysing and assessing the risks imposed through Stratospheric Aerosol Injection (SAI) research. SAI is a form of climate engineering that could cool the planet by enhancing its albedo through the injection of aerosols into the stratosphere. Researching such a technology creates systemic risks with a strong sociotechnical component. This component consists of the potential societal harm that a developing or new technology might cause to existing norms, values, institutions, and politics. The systemic risk framework is a valuable heuristic for this case, given the complex interdependencies of societal systems, infrastructures, markets, etc. At the same time, the systemic risk framework can be enhanced through the inclusion of a more robust and reflected ethical considerations on technological risks. Consequently, this article seeks to supplement the systemic risk governance framework with insights from technology ethics. Specifically, the paper offers an ethically reflective conception of societal value dynamism and stakeholder engagement and participation, tying it to existing systemic risk governance approaches.","ethics of technology; participation; risk governance; solar climate engineering; Systemic risk; values","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:9ba4387d-5ab6-4b89-9df5-96299e323655","http://resolver.tudelft.nl/uuid:9ba4387d-5ab6-4b89-9df5-96299e323655","Fostering responsible anticipation in engineering ethics education: how a multi-disciplinary enrichment of the responsible innovation framework can help","van Grunsven, J.B. (TU Delft Values Technology and Innovation; TU Delft Ethics & Philosophy of Technology); Stone, T.W. (TU Delft Ethics & Philosophy of Technology; Universität Bonn); Marin, L. (TU Delft Values Technology and Innovation; TU Delft Ethics & Philosophy of Technology)","","2023","It is crucial for engineers to anticipate the socio-ethical impacts of emerging technologies. Such acts of anticipation are thoroughly normative and should be cultivated in engineering ethics education. In this paper we ask: ‘how do we anticipate the socio-ethical implications of emerging technologies responsibly?’ And ‘how can such responsible anticipation be taught?’ We offer a conceptual answer, building upon the framework of Responsible Innovation and its four core practices: anticipation, reflexivity, inclusion, and responsiveness. We forge a more explicit link between the practices of anticipation, reflexivity, and inclusion, while also enriching them with insights from disability studies, STS, design theory, and philosophy. On this basis we present responsible anticipation as an activity of reflective problem framing grounded in epistemic humility. Via the RI-practice of responsiveness we present responsible anticipation as a creative approach to engineering ethics, offering engineering students a critical yet productive perspective on how ethics may inform innovation.","anticipation; disability studies; engineering ethics education; epistemic humility; problem framing; Responsible innovation","en","journal article","","","","","","","","","","Values Technology and Innovation","Ethics & Philosophy of Technology","","",""
"uuid:72baedb9-6a4d-48c8-95b7-10225db441ca","http://resolver.tudelft.nl/uuid:72baedb9-6a4d-48c8-95b7-10225db441ca","Using ChatGPT for human–computer interaction research: a primer","Tabone, W. (TU Delft Human-Robot Interaction); de Winter, J.C.F. (TU Delft Human-Robot Interaction)","","2023","ChatGPT could serve as a tool for text analysis within the field of Human–Computer Interaction, though its validity requires investigation. This study applied ChatGPT to: (1) textbox questionnaire responses on nine augmented-reality interfaces, (2) interview data from participants who experienced these interfaces in a virtual simulator, and (3) transcribed think-aloud data of participants who viewed a real painting and its replica. Using a hierarchical approach, ChatGPT produced scores or summaries of text batches, which were then aggregated. Results showed that (1) ChatGPT generated sentiment scores of the interfaces that correlated extremely strongly (r > 0.99) with human rating scale outcomes and with a rule-based sentiment analysis method (criterion validity). Additionally, (2) by inputting automatically transcribed interviews to ChatGPT, it provided meaningful meta-summaries of the qualities of the interfaces (face validity). One meta-summary analysed in depth was found to have substantial but imperfect overlap with a content analysis conducted by an independent researcher (criterion validity). Finally, (3) ChatGPT's summary of the think-aloud data highlighted subtle differences between the real painting and the replica (face validity), a distinction corresponding with a keyword analysis (criterion validity). In conclusion, our research indicates that, with appropriate precautions, ChatGPT can be used as a valid tool for analysing text data.","application programming interface (API); reproducibility; prompt engineering; human-subject research","en","journal article","","","","","","","","","","","Human-Robot Interaction","","",""
"uuid:437071f9-49a9-423f-bad1-d8a9da6522cb","http://resolver.tudelft.nl/uuid:437071f9-49a9-423f-bad1-d8a9da6522cb","Open Design Systems","Wolfert, A.R.M. (TU Delft Engineering Structures)","","2023","Current systems design and decision management methodologies can be single-sided, ignoring or failing to capture the dynamic interplay between multi-stakeholder preferences (‘what they want’) and system performances (‘what they can’). In addition, these methodologies often contain fundamental modelling errors and do not provide single best-fit solutions. This leaves designers or decision-makers without unique answers to their problems. Above all, mainstream higher education primarily applies instructivist and research-based learning methods, and therefore does not adequately prepare students for designing solutions to future complex problems.
This book introduces both a state-of-the-art participatory design methodology (Odesys), and a design-based learning concept (ODL), which together overcome the aforementioned issues. Odesys is a pure act of open design integration to confront conflicting socio-technical interests and is the key to unlocking these complexities to deliver socially responsible systems. Odesys’ design engine, the Preferendus, enables stakeholders to cooperatively identify their best-fit design synthesis. It employs a novel optimisation method that maximises the aggregated preferences, integrating sound mathematical and extended U-modelling via open technical-, social-, and purpose cycles. The art of ODL is a constructivist design-based and well-proven learning concept fostering students’ design capabilities to become open and persistent problem solvers. It is a reflective, creative, and engaged learning approach that opens human development and unlocks new knowledge and solutions.
The author also introduces new management features such as the corporate social identifier (CSI), the ‘socio-eco’ threefold organization model and U-model based open loop management. Finally, the author places Odesys & ODL within the integrative context of empiricism, rationalism, spiritualism, and constructivism to unite the open design impulse.
This book will be of interest to both academics and practitioners working in the field of complex systems design and managerial decision-making, and functions as a textbook on systems design and management for master students from diverse backgrounds.","Management; Technology; Engineering","en","book","IOS Press","978-1-64368-416-1","","","","","","","","Engineering Structures","","","",""
"uuid:eb6acbac-1d26-436b-a580-5b1778b6e757","http://resolver.tudelft.nl/uuid:eb6acbac-1d26-436b-a580-5b1778b6e757","Physical Evaluation Of The Hydrodynamic Stability Of An Eco-engineered Armouring Unit","Gutiérrez Martínez, Jorge (ECOncrete Tech Ltd.); Bezner, Maor (ECOncrete Tech Ltd.); Molenkamp, A. (Student TU Delft); van den Bos, J.P. (TU Delft Coastal Engineering; Royal Boskalis Westminster); Hofland, Bas (TU Delft Hydraulic Structures and Flood Risk); Leblanc, Philippe (ECOncrete Tech Ltd.); Rella, Andrew (ECOncrete Tech Ltd.); Rosenberg, Yaeli (ECOncrete Tech Ltd.); Sella, Ido (ECOncrete Tech Ltd.)","Cox, Dan (editor)","2023","ECOncrete®‘s Coastalock is an ecologically designed armour unit, providing an alternative and/or a complement to traditional armour layers with ecologically enhanced armouring that provides shoreline stabilization, while also creating well-defined local ecosystems that mimic natural rock pools. The 2D physical model tests performed at TU Delft focused on the stability, reflection and overtopping of a slope with regularly placed single layer Coastalock armour. The 2V:3H slope had an impermeable core, no wave breaking on the foreshore and no rock toe. The stability was seen to double, with stability number Ns (Ns= Hs/ΔDn50) increasing from roughly 2 to 4 and above, by increasing the porosity between the blocks from spacing the units from 0percent to 25percent. So less concrete use led to more stability. The mean overtopping discharge could be characterized by a roughness factor of gamma_f = 0.610 (for 25percent spacing). A key goal of the Coastalock development is to demonstrate that with the use of innovative eco-engineered armour unit design it is now possible to add ecological considerations into the design process to promote biodiversity and provide ecosystem services, achieving both structural and ecological goals.","Nature Inclusive Design (NID); biodiversity; marine habitat; ecological engineering; coastal protection; bioenhancing concrete; single layer armour unit; physical modelling","en","conference paper","ASCE - COPRI","","","","","","","","","","Coastal Engineering","","",""
"uuid:1100355f-4067-4774-a6b9-27c8238244c8","http://resolver.tudelft.nl/uuid:1100355f-4067-4774-a6b9-27c8238244c8","Teaching Engineering as a design science","Rooij, R.M. (TU Delft Spatial Planning and Strategy); Bossen, R.H. (TU Delft Education and Student Affairs)","Lyng, Reidar (editor); Bennedsen, Jens (editor); Bettaieb, Lamjed (editor)","2023","In this paper, we take the position that teaching engineering itself is a design science. Engineering educators worldwide creatively design, implement, and evaluate new ways of teaching to facilitate the learning of their students and to respond to various societal challenges. Sadly, their teaching and course design discoveries often remain with them. By representing successful experiences in engineering education as structured pedagogical patterns, we could develop this vital professional knowledge collectively into a so-called pattern language. The pattern language method acknowledges the complexity of instructional design and divides it into smaller and more understandable pieces. One piece is called a ‘pattern’. This paper aims to set the argument of why and how to develop a pedagogical pattern language for engaging and activating engineering education. In Delft, we see this pedagogical language as a part of TU Delft’s so-called ecosystem approach toward learning and teaching. TU Delft recognizes the need among students for impact-driven education that matches the way this generation learns and what our society needs. Successful ecosystem pedagogies will be the core of the intended pedagogical pattern language. It is our idea to develop this pattern language in close cooperation with the teaching communities of TU Delft, that is the TUD Teaching Academy, the 4TU Centre of Engineering Education, and CDIO.","engaging engineering pedagogy; eco-systems communities for teachers; pattern language; scholarship of teaching and learning; Standards: 8, 9, 10","en","conference paper","NTNU","","","","","","","","","Education and Student Affairs","Spatial Planning and Strategy","","",""
"uuid:018946ce-09f0-4431-a0b7-88c100df12a9","http://resolver.tudelft.nl/uuid:018946ce-09f0-4431-a0b7-88c100df12a9","Creating a circular healthcare economy: Circular strategies for sustainable healthcare","van Straten, Bart (TU Delft Medical Instruments & Bio-Inspired Technology); Alvino, Letizia (University of Twente); Horeman, T. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2023","Our world is the only planet, as far as we know, which harbors life. The number of humans on our planet has grown tremendously in recent centuries. In 1800 one billion humans occupied our earth; on 15 November 2022, this number reached 8 billion.
A result of this growth, the emissions of carbon dioxide (CO2), the primary greenhouse gas emitted by human activities, drastically increased. The increased concentrations of greenhouse gases in our atmosphere foster the long-term increase of our earth’s temperatures, also referred to as global warming.
While the earth’s population grew, so did our mass consumption society. After the Second World War humanity witnessed gigantic global economic development with great technological improvements. Computers, laptops, airplanes, tablets and Internet of Things connected humans all over the world. The hunger for plastics and steel grew as all products had to be manufactured in ever-increasing volumes. As the economy developed, our consumption grew apace.
The healthcare sector has seen the same increase of consumption. The number of patients grew, and so did the number of single-use medical products. As products become more complex and more different materials were combined., recycling became more difficult. Thus, hospitals transformed into waste factories with ever-growing waste streams. The consumption of (disposable) medical devices takes up scarce raw materials and contributes to the growing CO2 emissions.
In this book, Van Straten, Alvino and Horeman present their findings on how to create a sustainable healthcare economy by introducing different circular strategies. In 9 chapters, they present a wide variation of studies as practical cases to show what strategies and actions can be taken in order to implement sustainable strategies for a circular healthcare.
This book was written in line with the courses the authors developed at TU Extension School, the open online education edX platform of Delft University of Technology/TU Delft, a leading university in science and technology, recognized for its world-class research. This book is a manual for everyone who follows the online course ‘Circular strategies for a sustainable healthcare’, but certainly also for everyone who wants to discover more about circular strategies and wants to understand the principles and practices of circular economy and urban mining. This book is suitable for students, researchers, policymakers and practitioners in the fields of healthcare sustainability, management, business and economics.","circular economy; sustainable; circular engineering; waste recycling","en","book","Delft University of Technology","978-94-6366-729-6","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:da3b1ae8-c54a-48d9-a169-8dd6a936719a","http://resolver.tudelft.nl/uuid:da3b1ae8-c54a-48d9-a169-8dd6a936719a","Framing Supradisciplinary Research for Intellectualized Cyber-Physical Systems: An Unfinished Story","Horvath, I. (TU Delft Cyber-Physical Systems)","","2023","Conceptualization and design of intellectualized, socialized, and personalized cyber-physical systems (CPSs) need integration of existing knowledge across the involved disciplines, as well as exploration and synthesis of novel knowledge beyond disciplinary boundaries. The latter needs a combined use of interdisciplinary, multidisciplinary, and transdisciplinary research. Supradisciplinary research has emerged as a new doctrine of combining these research approaches from epistemological, methodological, and procedural perspectives. However, no methodology can be found in the literature that could facilitate the practical execution of supradisciplinary research programs. This position paper proposes a conceptual framework that can be used as a blueprint for operationalization of such undertakings. The framework rests on six generic pillars: (i) problematics, (ii) infrastructure, (iii) method, (iv) stakeholders, (v) operations, and (vi) knowledge. It specifies the major concerns that have to be taken into consideration in a systematic manner in developing executional scenarios for supradisciplinary research. The framework facilitates (i) management of research organization tasks, (ii) joint formation of shared research infrastructure, (ii) setting up concrete research program, (iii) academic partnering and public stakeholder involvement, (iv) process flow management and capacity/competence allocation, (v) a holistic knowledge synthesis, assessment, and consolidation, and (vi) development of tools supporting the preparation and execution of large-scale supradisciplinary research. In its current form, it does not cover the specific societal and personal issues of a successful organization of the inquiry at individual researchers, research teams, and research community levels. A community-based follow-up research may focus on the practical application and testing of the framework in concrete cases-a task that an individual researcher cannot address.","cyber-physical system design and operation; knowledge engineering","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-11-03","","","Cyber-Physical Systems","","",""
"uuid:dd339358-a051-440b-8bdb-89f7d32a3a36","http://resolver.tudelft.nl/uuid:dd339358-a051-440b-8bdb-89f7d32a3a36","Expanding the genome editing toolbox of Saccharomyces cerevisiae with the endonuclease ErCas12a","Bennis, N.X. (TU Delft BT/Industriele Microbiologie); Anderson, Jonah P. (Student TU Delft); Kok, Siebe M.C.; Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2023","ErCas12a is a class 2 type V CRISPR-Cas nuclease isolated from Eubacterium rectale with attractive fundamental characteristics, such as RNA self-processing capability, and lacks reach-through royalties typical for Cas nucleases. This study aims to develop a ErCas12a-mediated genome editing tool applicable in the model yeast Saccharomyces cerevisiae. The optimal design parameters for ErCas12a editing in S. cerevisiae were defined as a 21-nt spacer flanked by 19 nt direct repeats expressed from either RNApolII or III promoters, achieving near 100% editing efficiencies in commonly targeted genomic locations. To be able to transfer the ErCas12a genome editing tool to different strain lineages, a transportable platform plasmid was constructed and evaluated for its genome editing efficiency. Using an identical crRNA expression design, the transportable ErCas12a genome editing tool showed lower efficiency when targeting the ADE2 gene. In contrast to genomic Ercas12a expression, episomal expression of Ercas12a decreases maximum specific growth rate on glucose, indicating ErCas12a toxicity at high expression levels. Moreover, ErCas12a processed a multispacer crRNA array using the RNA self-processing capability, which allowed for simultaneous editing of multiple chromosomal locations. ErCas12a is established as a valuable addition to the genetic toolbox for S. cerevisiae.","ErCas12a (MAD7); Saccharomyces cerevisiae; CRISPR–Cas; genome engineering; multiplexing","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:18fc578e-10b5-4c66-8bdb-6ed230da056f","http://resolver.tudelft.nl/uuid:18fc578e-10b5-4c66-8bdb-6ed230da056f","Enhancing retention and transfer in mathematics in engineering education practice","Klaassen, R.G. (TU Delft Policy & Implementation); Cabo, A.J. (TU Delft Statistics)","Reilly, Ger (editor); Murphy, Mike (editor); Nagy, Balazs Vince (editor); Jarvinen, Hannu-Matti (editor)","2023","This article is a reflection of a SEFI workshop on Retention. In the workshop, a SWOT Analysis has been realised of four pedagogical solutions addressing Retention in undergraduate STEM education. The pedagogical solutions are programmatic assessment, micro-credentials for online mathematics (support) learning modules, autonomous and self-regulated learning and mathematical competencies for learning. Results have provided insights into the relevance and feasibility of implementation.","Mathematics Competencies; Transfer Mathematics to Engineering","en","conference paper","","","","","","","","","","","Statistics","","",""
"uuid:d1d8a6f2-25c2-4408-92dd-9e35ff9bc50f","http://resolver.tudelft.nl/uuid:d1d8a6f2-25c2-4408-92dd-9e35ff9bc50f","Normative Uncertainty in Solar Climate Engineering Research Governance","Hofbauer, B. (TU Delft Ethics & Philosophy of Technology)","","2023","This paper explores what kind of uncertainty a research program governing solar climate engineering through Stratospheric Aerosol Injection (SAI) needs to account for. Specifically, it tries to answer two central issues with regards to SAI research and it’s ethical evaluation: One, what irreducible uncertainties remain throughout the decision-process, and, two, how do these remaining uncertainties affect the ethical evaluation of SAI research. The main assumption is that decisions on SAI research governance will be made under normative uncertainty, i.e. situations under irreducible knowledge-constraints that arise in concrete, practical decision-contexts. These decision-contexts are multi-lateral and empirically ambiguous, and the decision-makers need to reconcile a plurality of values. While normative uncertainty complicates the ethical evaluation of policy decisions, I argue that moral considerations can be accommodated through the inclusion of recognitional, participatory justice approaches, as well as adaptive and anticipatory governance methods.","adaptive planning; anticipatory governance; Normative uncertainty; participatory justice; solar climate engineering","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:efbea901-e16b-4e6f-8d01-ecb9122dce36","http://resolver.tudelft.nl/uuid:efbea901-e16b-4e6f-8d01-ecb9122dce36","City of the Future Graduation Lab: Experiences in Multidisciplinary Education","","Cavallo, R. (editor); Kuijper, J.A. (editor); Harteveld, Maurice (editor); Carreiro Matias, Marcelo (editor); Ulkü, Mesut (editor); Drašković, Sonja (editor)","2023","The Cross Domain City of the Future Graduation Lab, situated in the Faculty of Architecture and the Built Environment at TU Delft, has been a pioneer in experimenting with a multidisciplinary approach to education on the built environment. Drawing upon this expertise over the past years, this book reflects on multidisciplinarity in the built environment and its implementation in education on the built environment. How should one approach multidisciplinarity in education and practice? What encompasses its core elements, benefits, and challenges?
By addressing these questions, the book aims to inform students and practitioners within the realm of the built environment by sharing insights from experiences in multidisciplinary education. It presents eight conclusions regarding the future of multidisciplinary education and, thereby, seeks to contribute to a more humane and sustainable future for cities.","City; Future; Multidisciplinarity; Design; Education; Engineering; Graduation Lab; Built Environment; Architecture; Urban Design; Management; Geomatics; Transport; Infrastructure; Logistics; Collaboration","en","book","TU Delft OPEN Publishing","978-94-6366-686-2","","","","","","","","","Theory, Territories & Transitions","","",""
"uuid:081b2873-b53f-4513-8b4c-be1217875dd4","http://resolver.tudelft.nl/uuid:081b2873-b53f-4513-8b4c-be1217875dd4","Large-scale morphological changes and sediment budget of the Western Scheldt estuary 1955–2020: the impact of large-scale sediment management","Elias, Edwin P.L. (Deltares); van der Spek, A.J.F. (Deltares; Universiteit Utrecht); Wang, Zhengbing (TU Delft Coastal Engineering); Cleveringa, Jelmer (ARCADIS Nederland; Universiteit Utrecht); Jeuken, Claire J. L. (Deltares); Taal, Marcel (Deltares); van der Werf, Jebbe (University of Twente; Deltares)","","2023","In the Western Scheldt estuary, like in many estuaries, safe navigation, flood protection, and ecological targets require a balanced and sustainable sediment management. A thorough understanding of the morphodynamic functioning of the estuary and its response to changes in hydrodynamics (natural sediment transport) and large-scale interventions is imperative. This paper presents a detailed overview of over 65 years of morphological changes and a comprehensive sediment budget of the Western Scheldt estuary that is based on analysis of a unique series of frequent bathymetric surveys and historical data on human–sediment interactions of dredging, dredge disposal and sand mining. Solving the sediment budget reveals an annual sediment import of 2.2 million m3. The highest sediment imports occurred between 1980–1994 and 2005–2020 (2.9 and 3.7 million m3/year). A 1.3 million m3/year net export prevailed between 1994 and 2005. Natural variations in the hydrodynamics (e.g., tidal asymmetry and amplification) and sediment transports cannot explain the derived temporal variations in sediment import rates. Anthropogenic activities play a dominant role. Capital dredging of the main navigation channel has led to channel deepening and significantly increased dredge and disposal volumes. Disposal on tidal flats and in the secondary channel leads to a long-term storage of sand and, consequently, a local increase in bed level and a sand deficit in the remainder of the system that results in increased sediment imports. Large-scale disposal in the western part of the estuary can (temporarily) reverse the sediment exchange between the estuary and its mouth area, as observed between 1994 and 2005. Apparently, large-scale anthropogenic reallocation of sediment by dredging and/or disposal as part of navigation channel improvement, sand mining or nourishment essentially influences the morphological development of the Western Scheldt estuary. This reveals responsibilities as well as opportunities of sediment management for the Western Scheldt and similar estuaries worldwide.","Western Scheldt; sediment budget; coastal morphodynamics; impact of large-scale engineering","en","review","","","","","","","","","","","Coastal Engineering","","",""
"uuid:30d2949b-c2cf-47c1-8932-bd1b895ec5d2","http://resolver.tudelft.nl/uuid:30d2949b-c2cf-47c1-8932-bd1b895ec5d2","A resilience view on health system resilience: a scoping review of empirical studies and reviews","Copeland, S.M. (TU Delft Ethics & Philosophy of Technology); Hinrichs-Krapels, S. (TU Delft Policy Analysis); Fecondo, Federica (Student TU Delft); Santizo, Esteban Ralon (Student TU Delft); Bal, Roland (Erasmus Universiteit Rotterdam); Comes, M. (TU Delft Transport and Logistics)","","2023","BACKGROUND: Prompted by recent shocks and stresses to health systems globally, various studies have emerged on health system resilience. Our aim is to describe how health system resilience is operationalised within empirical studies and previous reviews. We compare these to the core conceptualisations and characteristics of resilience in a broader set of domains (specifically, engineering, socio-ecological, organisational and community resilience concepts), and trace the different schools, concepts and applications of resilience across the health literature. METHODS: We searched the Pubmed database for concepts related to 'resilience' and 'health systems'. Two separate analyses were conducted for included studies: a total of n = 87 empirical studies on health system resilience were characterised according to part of health systems covered, type of threat, resilience phase, resilience paradigm, and approaches to building resilience; and a total of n = 30 reviews received full-text review and characterised according to type of review, resilience concepts identified in the review, and theoretical framework or underlying resilience conceptualisation. RESULTS: The intersection of health and resilience clearly has gained importance in the academic discourse with most papers published since 2018 in a variety of journals and in response to external threats, or in reference to more frequent hospital crisis management. Most studies focus on either resilience of health systems generally (and thereby responding to an external shock or stress), or on resilience within hospitals (and thereby to regular shocks and operations). Less attention has been given to community-based and primary care, whether formal or informal. While most publications do not make the research paradigm explicit, 'resilience engineering' is the most prominent one, followed by 'community resilience' and 'organisational resilience'. The social-ecological systems roots of resilience find the least application, confirming our findings of the limited application of the concept of transformation in the health resilience literature. CONCLUSIONS: Our review shows that the field is fragmented, especially in the use of resilience paradigms and approaches from non-health resilience domains, and the health system settings in which these are used. This fragmentation and siloed approach can be problematic given the connections within and between the complex and adaptive health systems, ranging from community actors to local, regional, or national public health organisations to secondary care. Without a comprehensive definition and framework that captures these interdependencies, operationalising, measuring and improving resilience remains challenging.","Community resilience; Health systems; Resilience; Resilience engineering; Socio-ecological resilience; OA-Fund TU Delft","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:e743c73f-2c60-43a6-85fa-7c9531347405","http://resolver.tudelft.nl/uuid:e743c73f-2c60-43a6-85fa-7c9531347405","NextGEM: Next-Generation Integrated Sensing and Analytical System for Monitoring and Assessing Radiofrequency Electromagnetic Field Exposure and Health","Petroulakis, Nikolaos (Foundation for Research and Technology - Hellas (FORTH)); Mattsson, Mats-Olof (SciProof International AB, Ostersund); Chatziadam, Panos (Foundation for Research and Technology - Hellas (FORTH)); Simko, Myrtill (SciProof International AB, Ostersund); Gavrielides, Andreas (eBOS Technologies Limited, Nicosia); Yiorkas, Andrianos (eBOS Technologies Limited, Nicosia); Zeni, Olga (Consiglio Nazionale delle Ricerche (CNR-IREA), Napoli); Scarfi, MR (Consiglio Nazionale delle Ricerche (CNR-IREA), Napoli); Spirito, M. (TU Delft Electronics)","","2023","The evolution of emerging technologies that use Radio Frequency Electromagnetic Field (RF-EMF ) has increased the interest of the scientific community and society regarding the possible adverse effects on human health and the environment. This article provides NextGEM’s vision to
assure safety for EU citizens when employing existing and future EMF-based telecommunication technologies. This is accomplished by generating relevant knowledge that ascertains appropriate prevention and control/actuation actions regarding RF-EMF exposure in residential, public, and occupational settings. Fulfilling this vision, NextGEM commits to the need for a healthy living
and working environment under safe RF-EMF exposure conditions that can be trusted by people and be in line with the regulations and laws developed by public authorities. NextGEM provides a framework for generating health-relevant scientific knowledge and data on new scenarios of exposure to RF-EMF in multiple frequency bands and developing and validating tools for evidence-based risk assessment. Finally, NextGEM’s Innovation and Knowledge Hub (NIKH) will offer a standardized way for European regulatory authorities and the scientific community to store and assess project outcomes and provide access to findable, accessible, interoperable, and reusable (FAIR) data.
C ) compared to the traditional cosine distance used in the literature.","Empirical Software Engineering; Search-Based Software Testing; Test Case Prioritization; Wordnet; Natural Language Processing","en","conference paper","Springer","","","","","","","2024-06-24","","","Software Engineering","","",""
"uuid:d3f93a20-4152-48c4-8fc1-53f2b1f30ea1","http://resolver.tudelft.nl/uuid:d3f93a20-4152-48c4-8fc1-53f2b1f30ea1","Evolutionary Optimisation of a Flexible-Launcher Simple Adaptive Control System","Mooij, E. (TU Delft Astrodynamics & Space Missions)","","2023","Attitude control of conventional launchers is relatively easy and straightforward and gives an adequate performance when applied to the nominal vehicle and mission. However, in the presence of environmental disturbances and vehicle design uncertainties, more robust types of controllers are required to guarantee stable attitudes. This chapter discusses the application of Simple Adaptive Control for the pitch control of a conventional flexible launcher. Because of the large number of design parameters, an optimisation procedure based on an evolutionary algorithm has been applied. With a floating-point representation for the design parameters, stochastic universal sampling selection, arithmetic crossover and non-uniform mutation, the performance of the controller is analysed, and it is identified how the developed methodology can streamline the (conceptual) design phase. Application of Pareto ranking enabled the simultaneous minimisation of the state deviation and the control effort, while the oscillation of the control has been used as an optimisation criterion. A conclusive simulation shows the controller performance for the flexible launch system.","Control system design; Conventional launch system; Engine dynamics; Evolutionary optimisation; Simple adaptive control","en","book chapter","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-06-26","","","Astrodynamics & Space Missions","","",""
"uuid:3950d700-d10d-486f-90e5-f05323309d7c","http://resolver.tudelft.nl/uuid:3950d700-d10d-486f-90e5-f05323309d7c","Human Digital Twin, the Development and Impact on Design","Song, Y. (TU Delft Emerging Materials)","","2023","In the past decade, human digital twins (HDTs) attracted attention in both digital twin (DT) applications and beyond. In this paper, we discuss the concept and the development of HDTs, focusing on their architecture, key enabling technologies, and (potential) applications. Based on the literature, we identify personal data, model, and interface as three key modules in the proposed HDT architecture, supported by a data lake of human data and a model and interface library. Regarding the key enabling technologies that support the HDT functions, we envision that the internet of things (IoT) infrastructure, data security, wearables, human modeling, explainable artificial intelligence (AI), minimum viable sensing, and data visualization are closely associated with the development of HDTs. Finally, we investigate current applications of HDTs, with a particular emphasis on the opportunities that arise from leveraging HDTs in the field of personalized product design.","engineering informatics; human computer interfaces/interactions; information management; multiscale modeling and simulation","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-25","","","Emerging Materials","","",""
"uuid:c6646856-9d0b-435b-a576-4a15bd3fcfc0","http://resolver.tudelft.nl/uuid:c6646856-9d0b-435b-a576-4a15bd3fcfc0","Senescence during early differentiation reduced the chondrogenic differentiation capacity of mesenchymal progenitor cells","Voskamp, Chantal (Erasmus MC); Koevoet, Wendy J.L.M. (Erasmus MC); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Narcisi, Roberto (Erasmus MC)","","2023","Introduction: Mesenchymal stromal/progenitor cells (MSCs) are promising for cartilage cell-based therapies due to their chondrogenic differentiation capacity. However, MSCs can become senescent during in vitro expansion, a state characterized by stable cell cycle arrest, metabolic alterations, and substantial changes in the gene expression and secretory profile of the cell. In this study, we aimed to investigate how senescence and the senescence-associated secretory phenotype (SASP) affect chondrogenic differentiation of MSCs.
Methods: To study the effect of senescence, we exposed MSCs to gamma irradiation during expansion or during chondrogenic differentiation (the pellet culture). Western blot analysis was used to evaluate MSCs response to the chondrogenic inductor TGF-β.
Results: When senescence was induced during expansion or at day 7 of chondrogenic differentiation, we observed a significant reduction in the cartilage matrix. Interestingly, when senescence was induced at day 14 of differentiation, chondrogenesis was not significantly altered. Moreover, exposing chondrogenic pellets to the medium conditioned by senescent pellets had no significant effect on the expression of anabolic or catabolic cartilage markers, suggesting a neglectable paracrine effect of senescence on cartilage generation in our model. Finally, we show that senescent MSCs showed lower phosphorylated SMAD2 levels after TGFβ1 stimulation than control MSCs.
Conclusion: Overall, these results suggest that the occurrence of senescence in MSCs during expansion or early differentiation could be detrimental for cartilage tissue engineering.","senescence; cartilage; MSC; chondrogenesis; SASP; regenerative medicine; tissue engineering; TGFβ","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:222b05e0-4fd7-4504-8d7a-57827d90d722","http://resolver.tudelft.nl/uuid:222b05e0-4fd7-4504-8d7a-57827d90d722","Reshaping The Bio Medical Curriculum To Include Socialisation And Subjectification","Klaassen, R.G. (TU Delft Policy & Implementation); Bossen, R.H. (TU Delft Education and Student Affairs); Milano, C. (TU Delft Communication IO); Hellendoorn, J. (TU Delft Cognitive Robotics)","Reilly, Ger (editor); Murphy, Mike (editor); Nagy, Balazs Vince (editor); Jarvinen, Hannu-Matti (editor)","2023","University students are asked to become all-round human beings, knowing how to be engaged in Engineering in the future, as well as wholly socialised and going through personal development steps. However, how and where are the students supposed to acquire these skills? Do we already have them in the Higher Education programmes and curricula? This article explores low threshold steps that can be taken to tweak the curriculum and implicit professionalisation of staff towards incorporating transversal skills and reflective activities that allow students to develop to their full potential.. One is a roadmap Workshop identifying guiding principles and touchpoint activities for curricular change. The other is a survey on how transversal skills are currently thought to have been embedded in the curriculum.","Curricular Design & Development; Engineering Roles; Transversal Skills","en","conference paper","European Society for Engineering Education (SEFI)","","","","","","","","","Education and Student Affairs","Policy & Implementation","","",""
"uuid:454b72e5-4bb5-49ea-9d3b-d6242fd085d5","http://resolver.tudelft.nl/uuid:454b72e5-4bb5-49ea-9d3b-d6242fd085d5","Conceptual Disruption and the Ethics of Technology","Hopster, J. (Universiteit Utrecht); Brey, P. (University of Twente); Klenk, M.B.O.T. (TU Delft Ethics & Philosophy of Technology); Löhr, G. (Vrije Universiteit Amsterdam); Marchiori, S. (TU Delft Ethics & Philosophy of Technology); Lundgren, B. (Universiteit Utrecht); Scharp, K. (University of Twente)","van de Poel, lbo (editor); Frank, Lily (editor); Hermann, Julia (editor); Hopster, Jeroen (editor); Lenzi, Dominic (editor); Nyholm, Sven (editor); Taebi, Behnam (editor); Ziliotti, Elena (editor)","2023","This chapter provides a theoretical lens on conceptual disruption. It offers a typology of conceptual disruption, discusses its relation to conceptual engineering, and sketches a programmatic view of the implications of conceptual disruption for the ethics of technology. We begin by distinguishing between three different kinds of conceptual disruptions: conceptual gaps, conceptual overlaps, and conceptual misalignments. Subsequently, we distinguish between different mechanisms of conceptual disruption, and two modes of conceptual change. We point out that disruptions may be induced by technology, but can also be triggered by intercultural exchanges. Conceptual disruptions frequently yield conceptual uncertainty and may call for conceptual and ethical inquiry. We argue that a useful approach to address conceptual disruptions is to engage in conceptual engineering. We outline what conceptual engineering involves and argue that discussions on conceptual disruption and conceptual engineering can benefit from closer integration. In closing, we discuss the relevance of studying conceptual disruption for technology ethics, and point to the promise of this line of research to innovate practical philosophy at large.","Conceptual disruption; Conceptual engineering; Socially disruptive technologies","en","book chapter","Open Book Publishers","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:e534ed68-055a-4301-ad4f-c1e464c685a5","http://resolver.tudelft.nl/uuid:e534ed68-055a-4301-ad4f-c1e464c685a5","Sequence- and time-dependent maintenance scheduling in twice re-entrant flow shops","Eigbe, E. (TU Delft Algorithmics); De Schutter, B.H.K. (TU Delft Delft Center for Systems and Control); Nasri, Mitra (Eindhoven University of Technology); Yorke-Smith, N. (TU Delft Algorithmics)","","2023","Industrial and academic interest converge on scheduling flow shops with sequence- and time-dependent maintenance. We posit that anticipatory, integrated scheduling of operational and maintenance tasks leads to superior performance to purely 'wait-then-fix' handling of the maintenance tasks. Motivated by an industrial problem with (sequence dependent) setup times, maximum separation constraints, and a combination of sequence- and time- dependent maintenance tasks, this paper introduces an integer programming solution, a constraint programming solution and a heuristic solution based on list scheduling. The motivating use case provides a unique combination of concerns that is to the best of our knowledge, not yet studied in the literature. We build on existing work where we can by extending models for sequence-dependent maintenance scheduling to accommodate sequence- and time-dependent maintenance scheduling and also propose other new models. We show the relative performances of our methods through empirical evaluations and also show significant improvements - up to 25% reduction in makespan - when compared to a reactive scheduling approach that does not consider maintenance in its planning. Based on our evaluations on exact methods, constraint programming models scale better than mixed integer programming models for this problem.","Flexible manufacturing systems; Integer programming; Job shop scheduling; Maintenance engineering; maintenance scheduling; makespan minimisation; Parallel machines; Production; re-entrant flow shops; Scheduling","en","journal article","","","","","","","","","","Delft Center for Systems and Control","Algorithmics","","",""
"uuid:a669ae14-56de-4f2c-a3b8-767106be2d25","http://resolver.tudelft.nl/uuid:a669ae14-56de-4f2c-a3b8-767106be2d25","Biomimetic Approaches for the Design and Fabrication of Bone-to-Soft Tissue Interfaces","Pitta Kruize, Carlos (Student TU Delft); Panahkhahi, S. (TU Delft Biomaterials & Tissue Biomechanics); Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Diaz Payno, P.J. (TU Delft Biomaterials & Tissue Biomechanics); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics)","","2023","Bone-to-soft tissue interfaces are responsible for transferring loads between tissues with significantly dissimilar material properties. The examples of connective soft tissues are ligaments, tendons, and cartilages. Such natural tissue interfaces have unique microstructural properties and characteristics which avoid the abrupt transitions between two tissues and prevent formation of stress concentration at their connections. Here, we review some of the important characteristics of these natural interfaces. The native bone-to-soft tissue interfaces consist of several hierarchical levels which are formed in a highly specialized anisotropic fashion and are composed of different types of heterogeneously distributed cells. The characteristics of a natural interface can rely on two main design principles, namely by changing the local microarchitectural features (e.g., complex cell arrangements, and introducing interlocking mechanisms at the interfaces through various geometrical designs) and changing the local chemical compositions (e.g., a smooth and gradual transition in the level of mineralization). Implementing such design principles appears to be a promising approach that can be used in the design, reconstruction, and regeneration of engineered biomimetic tissue interfaces. Furthermore, prominent fabrication techniques such as additive manufacturing (AM) including 3D printing and electrospinning can be used to ease these implementation processes. Biomimetic interfaces have several biological applications, for example, to create synthetic scaffolds for osteochondral tissue repair.","additive manufacturing; biomimetics; bone-soft tissue interfaces; functional gradient; tissue interface engineering","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:5e1f276c-92a2-4600-89ad-1fa1a5dec79f","http://resolver.tudelft.nl/uuid:5e1f276c-92a2-4600-89ad-1fa1a5dec79f","Approaches for bacteriophage genome engineering","Mahler, M.S. (TU Delft BN/Stan Brouns Lab; University of Otago); Martins Costa, A.R. (TU Delft BN/Stan Brouns Lab; Kavli institute of nanoscience Delft); van Beljouw, S.P.B. (TU Delft BN/Stan Brouns Lab; Kavli institute of nanoscience Delft); Fineran, Peter C. (University of Otago); Brouns, S.J.J. (TU Delft BN/Stan Brouns Lab; Kavli institute of nanoscience Delft)","","2023","In recent years, bacteriophage research has been boosted by a rising interest in using phage therapy to treat antibiotic-resistant bacterial infections. In addition, there is a desire to use phages and their unique proteins for specific biocontrol applications and diagnostics. However, the ability to manipulate phage genomes to understand and control gene functions, or alter phage properties such as host range, has remained challenging due to a lack of universal selectable markers. Here, we discuss the state-of-the-art techniques to engineer and select desired phage genomes using advances in cell-free methodologies and clustered regularly interspaced short palindromic repeats-CRISPR associated protein (CRISPR-Cas) counter-selection approaches.","CRISPR-Cas; homologous recombination; phage engineering; rebooting; recombineering","en","review","","","","","","","","","","","BN/Stan Brouns Lab","","",""
"uuid:236561ad-b070-4acb-8553-21ddb021b04c","http://resolver.tudelft.nl/uuid:236561ad-b070-4acb-8553-21ddb021b04c","Evaluating classifiers in SE research: the ECSER pipeline and two replication studies","Dell'Anna, D. (TU Delft Control & Simulation); Aydemir, Fatma Başak (Boğaziçi University); Dalpiaz, Fabiano (Universiteit Utrecht)","","2023","Context: Automated classifiers, often based on machine learning (ML), are increasingly used in software engineering (SE) for labelling previously unseen SE data. Researchers have proposed automated classifiers that predict if a code chunk is a clone, if a requirement is functional or non-functional, if the outcome of a test case is non-deterministic, etc. Objective: The lack of guidelines for applying and reporting classification techniques for SE research leads to studies in which important research steps may be skipped, key findings might not be identified and shared, and the readers may find reported results (e.g., precision or recall above 90%) that are not a credible representation of the performance in operational contexts. The goal of this paper is to advance ML4SE research by proposing rigorous ways of conducting and reporting research. Results: We introduce the ECSER (Evaluating Classifiers in Software Engineering Research) pipeline, which includes a series of steps for conducting and evaluating automated classification research in SE. Then, we conduct two replication studies where we apply ECSER to recent research in requirements engineering and in software testing. Conclusions: In addition to demonstrating the applicability of the pipeline, the replication studies demonstrate ECSER’s usefulness: not only do we confirm and strengthen some findings identified by the original authors, but we also discover additional ones. Some of these findings contradict the original ones.","Automated classification; Machine learning; Replication study; Software engineering","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:54c67de1-7532-4e4c-b012-c9e98986fab2","http://resolver.tudelft.nl/uuid:54c67de1-7532-4e4c-b012-c9e98986fab2","Near-real-time satellite precipitation data ingestion into peak runoff forecasting models","Muñoz, Paul (Universidad de Cuenca); Corzo, Gerald (IHE Delft Institute for Water Education); Solomatine, D.P. (TU Delft Water Resources; IHE Delft Institute for Water Education; Water Problems Institute of Russian Academy of Sciences); Feyen, Jan (Katholieke Universiteit Leuven); Célleri, Rolando (Universidad de Cuenca)","","2023","Extreme peak runoff forecasting is still a challenge in hydrology. In fact, the use of traditional physically-based models is limited by the lack of sufficient data and the complexity of the inner hydrological processes. Here, we employ a Machine Learning technique, the Random Forest (RF) together with a combination of Feature Engineering (FE) strategies for adding physical knowledge to RF models and improving their forecasting performances. The FE strategies include precipitation-event classification according to hydrometeorological criteria and separation of flows into baseflow and directflow. We used ∼ 3.5 years of hourly precipitation information retrieved from two near-real-time satellite precipitation databases (PERSIANN-CCS and IMERG-ER), and runoff data at the outlet of a 3391-km2 basin located in the tropical Andes of Ecuador. The developed models obtained Nash-Sutcliffe efficiencies varying from 0.86 to 0.59 for lead times between 1 and 6 h. The best performances were obtained for peak runoffs triggered by short-extension precipitation events (<50 km2) where infiltration- or saturation-excess runoff responses are well learned by the RF models. Conversely, the forecasting difficulty is associated with extensive precipitation events. For such conditions, a deeper characterization of the biophysical characteristics of the basin is encouraged for capturing the dynamic of directflow across multiple runoff responses. All in all, the potential to employ near-real-time satellite precipitation and the use of FE strategies for improving RF forecasting provides hydrologists with new tools for real-time runoff forecasting in remote or complex regions.","Baseflow separation; Extreme runoff; Feature engineering; Forecasting; IMERG; PERSIANN; Tropical Andes","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:c5e63cc0-e7b9-4a54-9cac-cd2ebd2d1666","http://resolver.tudelft.nl/uuid:c5e63cc0-e7b9-4a54-9cac-cd2ebd2d1666","Understanding the effects of root structure on the mechanical behaviour of engineered plant root materials","Carrete, I.A. (TU Delft Design for Sustainability); Ghodrat, S. (TU Delft Emerging Materials); Scherer, Diana (Interwoven, Amsterdam); Karana, E. (TU Delft Emerging Materials)","","2023","Plant root growth can be altered by introducing obstacles in the path of growth. This principle is used in design to produce planar grid structures composed of interweaving roots. The Engineered Plant Root Materials (EPRMs) grown with this method have the potential to serve as environmentally sensitive alternatives for conventional materials, but their applications are delimited by their material properties. To bridge the gap in the wider application of these materials, the role of plant root structure and an agar-agar matrix are explored in relation to the mechanical properties of the EPRMs. Tensile tests were performed on five root configurations, ranging from single roots to grids of varying sizes. Heterogeneities in each configuration suggest poor load distribution throughout the structure. Agar-agar was introduced as a biopolymer matrix to improve load distribution and tensile properties. Digital microscopy at the intersection of grid cells suggests a correlation between cell size, root tip density, and material strength. The largest cell size (2 cm) had the highest root tip density and yield strength (0.568 ± 0.181 roots/mm2 and 0.234 ± 0.018 MPa, respectively), whereas the structure with the least root tips (1 cm) was 31 % weaker.","Biodesign; Biofabrication; Characterization; Engineered Living Materials (ELMs); Engineered Plant Root Materials (EPRMs); Growing Design; Natural Fiber Composites; Plant Roots","en","journal article","","","","","","","","","","","Design for Sustainability","","",""
"uuid:7ec6801c-68c5-4766-b701-37a952e48524","http://resolver.tudelft.nl/uuid:7ec6801c-68c5-4766-b701-37a952e48524","Design for values and conceptual engineering","Veluwenkamp, H.M. (TU Delft Ethics & Philosophy of Technology; Rijksuniversiteit Groningen); van den Hoven, M.J. (TU Delft Ethics & Philosophy of Technology)","","2023","Politicians and engineers are increasingly realizing that values are important in the development of technological artefacts. What is often overlooked is that different conceptualizations of these abstract values lead to different design-requirements. For example, designing social media platforms for deliberative democracy sets us up for technical work on completely different types of architectures and mechanisms than designing for so-called liquid or direct forms of democracy. Thinking about Democracy is not enough, we need to design for the proper conceptualization of these values. As we see it, we cannot responsibly engineer and innovate and shape technology in accordance with our moral values without engaging in systematic and continuous conceptual engineering: This is not only an academic, or theoretical issue, it is also not simply an issue for public policy or politics, or regulators, it has become a central problem for engineering and the world of technology. In this paper, we present a framework for doing the necessary conceptual work in the context of requirement engineering. We draw on the literature on conceptual engineering to lay out a methodology to (1) assess different conceptions and (2) to develop new conceptions. Moreover, we integrate this methodology with extant approaches in the philosophy of technology which aim at designing technological artefacts ethically. In the final section we apply this integrated framework to freedom in the context of social media networks.","Conceptual engineering; Control; Design and values; Freedom; Innovation; Value sensitive design","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Ethics & Philosophy of Technology","","",""
"uuid:d88294bb-5fe9-41ee-9a1b-ba9b8f5a6881","http://resolver.tudelft.nl/uuid:d88294bb-5fe9-41ee-9a1b-ba9b8f5a6881","Behavior of Engineered Cementitious Composites (ECCs) Subjected to Coupled Sustained Flexural Load and Salt Frost","Li, Yonghao (Shandong University); Zhang, Ning (Shandong Hi-Speed Engineering Test CO); Sun, Renjuan (Shandong University); Guan, Yanhua (Shandong University); Liu, Lemin (Shandong Expressway Infrastructure Construction Co); Tian, Changjin (Shandong University); Ling, Yifeng (Shandong University); Zhang, Hongzhi (Shandong University); Šavija, B. (TU Delft Materials and Environment)","","2023","The performance of engineered cementitious composites (ECCs) under coupled salt freezing and loaded conditions is important for its application on the transportation infrastructure. However, in most of the studies, the specimens were generally loaded prior to the freezing. The influence of sustained load was merely considered. To this end, four sustained deflection levels, i.e., 0%, 10%, 30% and 50% of the deflection at the ultimate flexural strength, and three salt concentrations (1%, 3% and 5%) were applied. Prior to the salt frost resistance test, the fluid absorption of ECC specimens under various conditions were measured. The changes in relative dynamic elastic modulus (RDEM) during the freeze–thaw cycles were captured. The depth and the content profile of free chloride were measured after the coupled sustained load and freezing and thawing cycles. It is shown that 3% NaCl solution leads to the largest deterioration in all cases. There is no visible flaking or damage occurring on the surface. The relationships between locally sustained flexural stress and RDEM loss and also locally sustained flexural stress and free chloride penetration depth were proposed and showed satisfactory results. It is concluded that when ECC is subjected to the FTCs under 1% de-ice salt solution, no depassivation of the steel is expected even under a large deflection level. In terms of 3% and 5% salt solution, the thickness of cover should be no less than 20 mm when a deflection level of 0.5 is applied.","chloride penetration depth; engineered cementitious composites (ECCs); free chloride profile; salt frost; sustained flexural load","en","journal article","","","","","","","","","","","Materials and Environment","","",""
"uuid:47a9f960-b538-40a5-9bdc-0bf46af444ad","http://resolver.tudelft.nl/uuid:47a9f960-b538-40a5-9bdc-0bf46af444ad","Health assessment framework of marine engines enabled by digital twins","Tsitsilonis, Konstantinos Marios (University of Strathclyde); Theotokatos, Gerasimos (University of Strathclyde); Patil, Chaitanya (University of Strathclyde); Coraddu, A. (TU Delft Ship Design, Production and Operations)","","2023","The advancements in digital twins when combined with the use of the machine learning tools can facilitate the effective health assessment and diagnostics of safety critical systems. This study aims at developing a framework to address the health assessment of marine engines utilising digital twins based on first-principles. This framework follows four distinct stages, with the former two including the marine engine digital-twin set up by customising the required thermodynamic models, as well as its calibration using tests trials data representing the engine healthy conditions. In the third stage, measurements from actual operating conditions are corrected and subsequently employed to develop the digital twin representing the prevailing conditions. The fourth stage deals with the engine health assessment by assessing health metrics derived from the developed digital twins. This framework is demonstrated in a case study of a large marine four-stroke nine-cylinder propulsion engine. The results demonstrate that three cylinders are identified to be underperforming leading to an average increase of the engine Brake Specific Fuel Consumption (BSFC) by 2.1%, whereas an average decreases of 6.8% in Indicated Mean Effective Pressure (IMEP) and 6.1% in the Exhaust Gas Temperature (EGT) are exhibited for the underperforming cylinders across the entire operating envelope. The developed digital twins facilitate the effective mapping of the engine performance for the entire operating envelope under several health conditions, providing enhanced insights for the current engine health status. The advantages of the proposed framework include the use of easily obtained data, and its application to several engine types including two and four-stroke engines for both propulsion and auxiliary use.","digital twins; engine health assessment; engine performance maps; Marine engine; measurements correction; model calibration; thermodynamic modelling","en","journal article","","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:2fd60cc5-4aca-4339-b51a-e11b227d133d","http://resolver.tudelft.nl/uuid:2fd60cc5-4aca-4339-b51a-e11b227d133d","Effectiveness of BMP-2 and PDGF-BB Adsorption onto a Collagen/Collagen-Magnesium-Hydroxyapatite Scaffold in Weight-Bearing and Non-Weight-Bearing Osteochondral Defect Bone Repair: In Vitro, Ex Vivo and In Vivo Evaluation","Xu, J. (Erasmus MC); Fahmy-Garcia, Shorouk (Erasmus MC); Wesdorp, Marinus A. (Erasmus MC); Forte, Lucia (Fin-Ceramica Faenza); De Luca, Claudio (Fin-Ceramica Faenza); Filardo, Giuseppe (Rizzoli Orthopaedic Institute); Labberté, Margot (University College Dublin); Kok, Joeri (Eindhoven University of Technology); Nickel, Joachim (Universitätsklinikum Würzburg); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC)","","2023","Despite promising clinical results in osteochondral defect repair, a recently developed bi-layered collagen/collagen-magnesium-hydroxyapatite scaffold has demonstrated less optimal subchondral bone repair. This study aimed to improve the bone repair potential of this scaffold by adsorbing bone morphogenetic protein 2 (BMP-2) and/or platelet-derived growth factor-BB (PDGF-BB) onto said scaffold. The in vitro release kinetics of BMP-2/PDGF-BB demonstrated that PDGF-BB was burst released from the collagen-only layer, whereas BMP-2 was largely retained in both layers. Cell ingrowth was enhanced by BMP-2/PDFG-BB in a bovine osteochondral defect ex vivo model. In an in vivo semi-orthotopic athymic mouse model, adding BMP-2 or PDGF-BB increased tissue repair after four weeks. After eight weeks, most defects were filled with bone tissue. To further investigate the promising effect of BMP-2, a caprine bilateral stifle osteochondral defect model was used where defects were created in weight-bearing femoral condyle and non-weight-bearing trochlear groove locations. After six months, the adsorption of BMP-2 resulted in significantly less bone repair compared with scaffold-only in the femoral condyle defects and a trend to more bone repair in the trochlear groove. Overall, the adsorption of BMP-2 onto a Col/Col-Mg-HAp scaffold reduced bone formation in weight-bearing osteochondral defects, but not in non-weight-bearing osteochondral defects.","animal model; biocompatible materials; bone morphogenetic proteins; osteochondral lesion; platelet-derived growth factor; regenerative medicine; tissue engineering; weight-bearing","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:d39f3c2f-1975-4497-9ee3-1cc04ae00e8f","http://resolver.tudelft.nl/uuid:d39f3c2f-1975-4497-9ee3-1cc04ae00e8f","Dynamic predictive maintenance for multiple components using data-driven probabilistic RUL prognostics: The case of turbofan engines","Mitici, M.A. (Universiteit Utrecht); de Pater, I.I. (TU Delft Air Transport & Operations); Barros, Anne (CNRS); Zeng, Zhiguo (CNRS)","","2023","The increasing availability of condition-monitoring data for components/systems has incentivized the development of data-driven Remaining Useful Life (RUL) prognostics in the past years. However, most studies focus on point RUL prognostics, with limited insights into the uncertainty associated with these estimates. This limits the applicability of such RUL prognostics to maintenance planning, which is per definition a stochastic problem. In this paper, we therefore develop probabilistic RUL prognostics using Convolutional Neural Networks. These prognostics are further integrated into maintenance planning, both for single and multiple components. We illustrate our approach for aircraft turbofan engines. The results show that the optimal replacement time for the engines is close to the lower bound of the 99% confidence interval of the RUL estimates. We also show that our proposed maintenance approach leads to a cost reduction of 53% compared to a traditional Time-based maintenance strategy. Moreover, compared with the ideal case when the true RUL is known in advance (perfect RUL prognostics), our approach leads to a limited number of failures. Overall, this paper proposes an end-to-end framework for data-driven predictive maintenance for multiple components, and showcases the potential benefits of data-driven predictive maintenance on cost and reliability.","Aircraft; C-MAPSS turbofan engines; Maintenance scheduling; Predictive maintenance planning; Probabilistic remaining useful life prognostics","en","journal article","","","","","","","","","","","Air Transport & Operations","","",""
"uuid:32c661b0-af31-46c5-a143-5546c45c05ae","http://resolver.tudelft.nl/uuid:32c661b0-af31-46c5-a143-5546c45c05ae","Influence of static–cyclic load misalignment on the drained tilting response of offshore monopiles in sand","Li, Z. (TU Delft Geo-engineering); Liu, Haoyuan (Norwegian Geotechnical Institute); Hicks, M.A. (TU Delft Geo-engineering); Pisano, F. (TU Delft Geo-engineering)","","2023","Offshore monopile foundations are exposed to misaligned wind and wave loadings, which are respectively dominated by (nearly) static and cyclic load components. While the response of these systems to unidirectional cyclic loading has been extensively investigated, only a few studies have been devoted to the realistic case of misaligned static and cyclic loads, and particularly to the effects of such misalignment on the accumulation of pile rotation under prolonged cycling. This paper presents a 3D finite-element (FE) modelling study on the relationship between load misalignment and cyclic monopile tilt under drained conditions, based on the use of the SANISAND-MS model to enable accurate simulation of cyclic sand ratcheting. After qualitatively identifying the relationship between relevant loading parameters and cyclic stress/densification mechanisms in the soil, specific parametric studies are performed to explore the impact on pile tilt accumulation. The results show that, in comparison to unidirectional loading, misaligned static–cyclic loading gives rise to lesser-known pile–soil interaction mechanisms: when the direction of cycling deviates from that of the static load, “cyclic compression” and “direct cyclic shearing” mechanisms begin to co-exist. This is quantitatively captured by a newly proposed empirical equation for monopile tilt calibrated against the 3D FE simulation results obtained in this work.","Cyclic loading; Finite-element modelling; Footings/foundations; Load misalignment; Offshore engineering; Sand","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:43bc5020-1406-432c-bd2e-32c99d156c53","http://resolver.tudelft.nl/uuid:43bc5020-1406-432c-bd2e-32c99d156c53","A scalable software package for time series reconstruction of remote sensing datasets on the Google Earth Engine platform","Zhou, J. (TU Delft Optical and Laser Remote Sensing; Central China Normal University); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Gao, Bo (Capital Normal University); Zhao, Feng (Central China Normal University); Cui, Yilin (Central China Normal University); Xiong, Xuqian (Central China Normal University); Liu, Xuan (Central China Normal University); Li, Dengchao (The First Geological brigade of Hubei Geological Bureau)","","2023","Spatiotemporal residual noise in terrestrial earth observation products, often caused by unfavorable atmospheric conditions, impedes their broad applications. Most users prefer to use gap-filled remote sensing products with time series reconstruction (TSR) algorithms. Applying currently available implementations of TSR to large-volume datasets is time-consuming and challenging for non-professional users with limited computation or storage resources. This study introduces a new open-source software package entitled ‘HANTS-GEE’ that implements a well-known and robust TSR algorithm, i.e. Harmonic ANalysis of Time Series (HANTS), on the Google Earth Engine (GEE) platform for scalable reconstruction of terrestrial earth observation data. Reconstruction tasks can be conducted on user-defined spatiotemporal extents when raw datasets are available on GEE. According to site-based and regional-based case evaluation, the new tool can effectively eliminate cloud contamination in the time series of earth observation data. Compared with traditional PC-based HANTS implementation, the HANTS-GEE provides quite consistent reconstruction results for most terrestrial vegetated sites. The HANTS-GEE can provide scalable reconstruction services with accelerated processing speed and reduced internet data transmission volume, promoting algorithm usage by much broader user communities. To our knowledge, the software package is the first tool to support full-stack TSR processing for popular open-access satellite sensors on cloud platforms.","gap-filling; Google Earth Engine; HANTS; remote sensing; Time series reconstruction","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:a986ac42-12e1-4a21-86be-6fdef45effd8","http://resolver.tudelft.nl/uuid:a986ac42-12e1-4a21-86be-6fdef45effd8","The contribution shift of ammonia-oxidizing archaea and bacteria to ammoxidation under Ag-NPs/SWCNTs/PS-NPs stressors in constructed wetlands","Yang, X. (TU Delft Sanitary Engineering; Chinese Academy of Sciences); Guo, Fucheng (Chongqing University); Liu, Tao (Chongqing University); He, Qiang (Chongqing University); Vymazal, Jan (Czech University of Life Sciences Prague); Chen, Yi (Chongqing University)","","2023","Ammonia-oxidizing microorganisms (AOMs, archaea (AOA) and bacteria (AOB)) are primarily responsible for the ammoxidation in constructed wetlands (CWs). However, little is known about evaluating the response of AOA and AOB to engineered nanomaterials (ENMs) and quantifying the shift of their contribution to ammoxidation. Herein, we operated a series of CWs exposing to silver nanoparticles (Ag-NPs), single-walled carbon nanotubes (SWCNTs), and polystyrene nano-sized plastics (PS-NPs) with the wastewater-accumulating concentration of ENMs for 180 days. The results showed that the abundance of AOA amoA gene in situ was far lower than that of AOB, while the abundance ratio of AOA to AOB increased by 15 folds after 180-day experiment. Using DNA stable isotope probing (DNA-SIP) experiment, we found that the active AOB microbiota varied substantially but the AOA was more stable across different groups. Furthermore, the co-occurrence analysis proved that ENMs stress increased the negative coexistence pattern of AOA and AOB; predictive functional profiling showed that the ENMs enhanced the functional advantage of AOA by inhibiting AOB (mainly hydroxylamine oxidation process). Finally, the contribution of AOA increased under exposing to SWCNTs (18.35%), PS-NPs (24.92%), and Ag-NPs (32.14%) compared with control group (0.03%) for 180 days. Despite this, AOB was still the primary executant of ammoxidation in CWs. Overall, in our study, the differences in activities and contributions of AOMs were quantified in CWs, and a significantly negative coexistence relationship between AOA and AOB was revealed when exposed to emerging nanomaterials.","Ammonia-oxidizing microorganisms; Ammoxidation; Constructed wetlands; DNA-stable isotope probe; Engineered nanomaterials","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-14","","","Sanitary Engineering","","",""
"uuid:30ca3257-ec6c-450a-896a-7ba54ab1c857","http://resolver.tudelft.nl/uuid:30ca3257-ec6c-450a-896a-7ba54ab1c857","Engineering a Highly Regioselective Fungal Peroxygenase for the Synthesis of Hydroxy Fatty Acids","Gomez de Santos, Patricia (Evoenzyme S.L., Madrid); González-Benjumea, Alejandro (CSIC - Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS)); Fernandez-Garcia, Angela (Institute of Catalysis, CSIC, Madrid); Aranda, Carmen (CSIC - Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS)); Wu, Y. (TU Delft BT/Biocatalysis); But, A. (TU Delft BT/Biocatalysis); Molina-Espeja, Patricia (Institute of Catalysis, CSIC, Madrid); Zhang, W. (TU Delft BT/Biocatalysis); Hollmann, F. (TU Delft BT/Biocatalysis)","","2023","The hydroxylation of fatty acids is an appealing reaction in synthetic chemistry, although the lack of selective catalysts hampers its industrial implementation. In this study, we have engineered a highly regioselective fungal peroxygenase for the ω-1 hydroxylation of fatty acids with quenched stepwise over-oxidation. One single mutation near the Phe catalytic tripod narrowed the heme cavity, promoting a dramatic shift toward subterminal hydroxylation with a drop in the over-oxidation activity. While crystallographic soaking experiments and molecular dynamic simulations shed light on this unique oxidation pattern, the selective biocatalyst was produced by Pichia pastoris at 0.4 g L−1 in a fed-batch bioreactor and used in the preparative synthesis of 1.4 g of (ω-1)-hydroxytetradecanoic acid with 95 % regioselectivity and 83 % ee for the S enantiomer.","Hydroxy Fatty Acids; Over-Oxidation; Protein Engineering; Regioselectivity; Unspecific Peroxygenase","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:34743270-0cfa-42cb-b6e9-7dbfbc42bc38","http://resolver.tudelft.nl/uuid:34743270-0cfa-42cb-b6e9-7dbfbc42bc38","Automated assessment of human engineered heart tissues using deep learning and template matching for segmentation and tracking","Rivera-Arbeláez, José M. (University of Twente); Keekstra, Danjel (University of Twente); Cofiño-Fabres, Carla (University of Twente); Boonen, Tom (River BioMedics); Dostanic, M. (TU Delft Microelectronics); ten Den, Simone A. (University of Twente); Vermeul, Kim (University of Twente); Mastrangeli, Massimo (TU Delft Microelectronics; TU Delft Electronic Components, Technology and Materials); van den Berg, A (TU Delft Structural Integrity & Composites; BIOS Lab on a Chip Group; University of Twente)","","2023","The high rate of drug withdrawal from the market due to cardiovascular toxicity or lack of efficacy, the economic burden, and extremely long time before a compound reaches the market, have increased the relevance of human in vitro models like human (patient-derived) pluripotent stem cell (hPSC)-derived engineered heart tissues (EHTs) for the evaluation of the efficacy and toxicity of compounds at the early phase in the drug development pipeline. Consequently, the EHT contractile properties are highly relevant parameters for the analysis of cardiotoxicity, disease phenotype, and longitudinal measurements of cardiac function over time. In this study, we developed and validated the software HAARTA (Highly Accurate, Automatic and Robust Tracking Algorithm), which automatically analyzes contractile properties of EHTs by segmenting and tracking brightfield videos, using deep learning and template matching with sub-pixel precision. We demonstrate the robustness, accuracy, and computational efficiency of the software by comparing it to the state-of-the-art method (MUSCLEMOTION), and by testing it with a data set of EHTs from three different hPSC lines. HAARTA will facilitate standardized analysis of contractile properties of EHTs, which will be beneficial for in vitro drug screening and longitudinal measurements of cardiac function.","automated tracking; cardiac performance; contractile force; deep learning; engineered heart tissues; segmentation; sub-pixel interpolation; template matching","en","journal article","","","","","","","","","","Microelectronics","Electronic Components, Technology and Materials","","",""
"uuid:89122797-c8c1-4f03-aa68-ceb8f54e1de4","http://resolver.tudelft.nl/uuid:89122797-c8c1-4f03-aa68-ceb8f54e1de4","Suppression of auto-fluorescence from high-resolution 3D polymeric architectures fabricated via two-photon polymerization for cell biology applications","Sharaf, A.M.S.E. (TU Delft Micro and Nano Engineering); Frimat, J. P. (Leiden University Medical Center); Kremers, G. J. (Erasmus MC); Accardo, A. (TU Delft Micro and Nano Engineering)","","2023","Two-photon polymerization (2PP) has provided the field of cell biology with the opportunity to fabricate precisely designed microscaffolds for a wide range of studies, from mechanobiology to in vitro disease modelling. However, a multitude of commercial and in-house developed photosensitive materials employed in 2PP suffers from high auto-fluorescence in multiple regions of the spectrum. In the context of in vitro cell biological studies, this is a major problem since one of the main methods of characterization is fluorescence microscopy of immuno-stained cells. This undesired auto-fluorescence of microscaffolds affects the efficiency of such an analysis as it often overlaps with fluorescent signals of stained cells rendering them indistinguishable from the scaffolds. Here, we propose two effective solutions to suppress this auto-fluorescence and compare them to determine the superiority of one over the other: photo-bleaching with a powerful UV point source and auto-fluorescence quenching via Sudan Black B (SBB). The materials used in this study were all commercially available, namely IP-L, IP-Dip, IP-S, and IP-PDMS. Bleaching was shown to be 61.7–92.5% effective in reducing auto-fluorescence depending on the material. On the other hand, SBB was shown to be 33–95.4% effective. The worst result in presence of SBB (33%) was in combination with IP-PDMS since the adsorption of the material on IP-PDMS was not sufficient to fully quench the auto-fluorescence. However, auto-fluorescence reduction was significantly enhanced when activating the IP-PDMS structures with oxygen plasma for 30 s. Moreover, we performed a cell culture assay using a human neuroblastoma cell line (SH-SY5Y) to prove the effectiveness of both methods in immunofluorescence characterization. SBB presented a lower performance in the study especially in presence of 2PP-fabricated microchannels and microcages, within which the differentiated SH-SY5Y cells migrated and extended their axon-like processes, since the SBB obstructed the fluorescence of the stained cells. Therefore, we concluded that photo-bleaching is the optimal way of auto-fluorescence suppression. In summary, this study provides a systematic comparison to answer one of the most pressing issues in the field of 2PP applied to cell biology and paves the way to a more efficient immunofluorescence characterization of cells cultured within engineered in vitro microenvironments.","Auto-fluorescence quenching; Auto-fluorescence suppression; Cell engineered microenvironments; Fluorescence microscopy; Two-photon polymerization; UV-bleaching","en","journal article","","","","","","","","","","","Micro and Nano Engineering","","",""
"uuid:47f585c1-04ef-4b87-9cf5-9198f88d4331","http://resolver.tudelft.nl/uuid:47f585c1-04ef-4b87-9cf5-9198f88d4331","SIMD vectorization for simultaneous solution of locally varying linear systems with multiple right-hand sides","Kühn, Martin J. (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Holke, Johannes (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Lutz, Annette (Technische Universität Darmstadt); Thies, J. (TU Delft Numerical Analysis); Röhrig-Zöllner, Melven (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Bleh, Alexander (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Backhaus, Jan (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Basermann, Achim (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR))","","2023","Developments in numerical simulation of flows and high-performance computing influence one another. More detailed simulation methods create a permanent need for more computational power, while new hardware developments often require changes to the software to exploit new hardware features. This dependency is very pronounced in the case of vector-units which are featured by all modern processors to increase their numerical throughput but require vectorization of the software to be used efficiently. We study the vectorization of a simulation method that exhibits an inherent level of vector-parallelism. This is of particular interest as SIMD operations will hopefully be available with std::simd in a future C++ standard. The simulation method considered here results in the simultaneous solution of multiple sparse linear systems of equations which only differ by their main diagonal and right-hand sides. Such structure arises in the simulation of unsteady flow in turbomachinery by means of a frequency domain approach called harmonic balance.","Computational fluid dynamics; Frequency domain methods; High-performance computing; Performance engineering; SIMD optimization; Sparse iterative solvers","en","journal article","","","","","","","","","","","Numerical Analysis","","",""
"uuid:6bf58392-5a6f-4a74-b4ee-e0f7ab4da982","http://resolver.tudelft.nl/uuid:6bf58392-5a6f-4a74-b4ee-e0f7ab4da982","In Vitro Mineralisation of Tissue-Engineered Cartilage Reduces Endothelial Cell Migration, Proliferation and Tube Formation","Ji, Encheng (Erasmus MC); Leijsten, Lieke (Erasmus MC); Witte-Bouma, Janneke (Erasmus MC); Rouchon, Adelin (University of Basel); Di Maggio, Nunzia (University of Basel); Banfi, Andrea (University of Basel); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Farrell, Eric (Erasmus MC); Lolli, Andrea (Erasmus MC)","","2023","Tissue engineering bone via endochondral ossification requires the generation of a cartilage template which undergoes vascularisation and remodelling. While this is a promising route for bone repair, achieving effective cartilage vascularisation remains a challenge. Here, we investigated how mineralisation of tissue-engineered cartilage affects its pro-angiogenic potential. To generate in vitro mineralised cartilage, human mesenchymal stromal cell (hMSC)-derived chondrogenic pellets were treated with β-glycerophosphate (BGP). After optimising this approach, we characterised the changes in matrix components and pro-angiogenic factors by gene expression analysis, histology and ELISA. Human umbilical vein endothelial cells (HUVECs) were exposed to pellet-derived conditioned media, and migration, proliferation and tube formation were assessed. We established a reliable strategy to induce in vitro cartilage mineralisation, whereby hMSC pellets are chondrogenically primed with TGF-β for 2 weeks and BGP is added from week 2 of culture. Cartilage mineralisation determines loss of glycosaminoglycans, reduced expression but not protein abundance of collagen II and X, and decreased VEGFA production. Finally, the conditioned medium from mineralised pellets showed a reduced ability to stimulate endothelial cell migration, proliferation and tube formation. The pro-angiogenic potential of transient cartilage is thus stage-dependent, and this aspect must be carefully considered in the design of bone tissue engineering strategies.","angiogenesis; bone tissue engineering; endochondral ossification; mesenchymal stromal cells; mineralisation","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:440e2ef9-c40c-429d-9595-99159e435828","http://resolver.tudelft.nl/uuid:440e2ef9-c40c-429d-9595-99159e435828","Expanding the family of genetically encoded voltage indicators with a candidate Heliorhodopsin exhibiting near-infrared fluorescence","Ganapathy, S. (TU Delft ImPhys/Brinks group; University of California; UCSD School of Medicine, San Diego); Meng, X. (TU Delft ImPhys/Brinks group); Mossel, D.D.M.; Jagt, Mels (Student TU Delft); Brinks, D. (TU Delft ImPhys/Brinks group; Erasmus MC)","","2023","Genetically encoded voltage indicators, particularly those based on microbial rhodopsins, are gaining traction in neuroscience as fluorescent sensors for imaging voltage dynamics with high-spatiotemporal precision. Here we establish a novel genetically encoded voltage indicator candidate based on the recently discovered subfamily of the microbial rhodopsin clade, termed heliorhodopsins. We discovered that upon excitation at 530 to 560 nm, wildtype heliorhodopsin exhibits near-infrared fluorescence, which is sensitive to membrane voltage. We characterized the fluorescence brightness, photostability, voltage sensitivity, and kinetics of wildtype heliorhodopsin in HEK293T cells and further examined the impact of mutating key residues near the retinal chromophore. The S237A mutation significantly improved the fluorescence response of heliorhodopsin by 76% providing a highly promising starting point for further protein evolution.","fluorescence microscopy; neuroscience; protein engineering; rhodopsins; voltage sensors","en","journal article","","","","","","","","","","","ImPhys/Brinks group","","",""
"uuid:43e56678-b1b7-4c0b-86ab-f7bab139a717","http://resolver.tudelft.nl/uuid:43e56678-b1b7-4c0b-86ab-f7bab139a717","Effect of coordination number of particle contact force on rutting resistance of asphalt mixture","Niu, D. (Chang'an University); Shi, Weibo (Chang'an University); Wang, C. (TU Delft Pavement Engineering); Xie, Xiwang (Jiangsu Sobute New Materials Co. Ltd); Niu, Yanhui (Chang'an University)","","2023","Optimizing asphalt mix design at the indoor stage is of significant importance for enhancing the rutting resistance of asphalt mixture, which is affected by its structural characteristics. In this work, the coordination number of particle contact force (CNpcf) was proposed as an indicator to represent contact characteristics of skeleton structure aggregates in asphalt mixture. Nine asphalt mixtures with different gradations were designed, and the relationship of CNpcf with the number of aggregate contact zones (CZ) was established by combining rutting tests and digital image processing technique (DIP). The Mann-Whitney U test was implemented to analyze the distribution properties of inter-particle contacts before and after the rutting test. In addition, the resistance to the further expansion of rutting was analyzed. The results revealed a significant positive correlation (PCCs = 0.843, R2 = 0.711) between CNpcf and CZ. The content of coarse aggregates in the dominant structure did not exhibit monotonic related to anti-rutting performance of the asphalt mixture. Therefore, an optimum aggregate content of 57% was utilized. The Mann-Whitney U test revealed that the mesoscale skeleton structure of the asphalt mixes before and after rutting exhibited excellent stability. This study further indicated the applicability of combining CNpcf to adjust the mix design to enhance the rutting resistance of asphalt mixture and to prevent rutting expansion in flexible pavement.","Asphalt mixture; Digital image technology; Mann-Whitney U test; Road engineering; Rutting resistance; Skeleton structure","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-11-26","","","Pavement Engineering","","",""
"uuid:c1600edf-9d58-4302-9864-5702e568a44e","http://resolver.tudelft.nl/uuid:c1600edf-9d58-4302-9864-5702e568a44e","Chloride penetration resistance of engineered cementitious composite (ECC) subjected to sustained flexural loading","Wang, Chuan (Shandong Hi-Speed Group); Sun, Renjuan (Shandong University); Hu, Xinlei (Chongqing Luneng Development Group Co, Ltd.); Guan, Yanhua (Shandong University); Yang, Yingzi (Harbin Institute of Technology); Lu, Wei (Shandong University); Tian, Jun (Shandong Hi-Speed Group); Zhang, Hongzhi (Shandong University); Ge, Zhi (Shandong University); Šavija, B. (TU Delft Materials and Environment)","","2023","This paper presents a research on the chloride penetration behavior of engineered cementitious composites (ECC) under sustained flexural loads. Three load levels, i.e. 30 %, 60 % and 75 % of the ultimate flexural load were used. Chloride diffusion depth and concentration profile were measured 30, 60 and 150 days after the specimen was exposed to NaCl solution and compared with pre-loaded specimens. Influence of the sustained local bending stress and microcracks were investigated. It shows that under sustained loads, the relationship between the surface chloride content and maximum normal tensile stress can be described using an exponential equation. A binary model was developed to explain the correlation among the chloride ion diffusion coefficient, maximum normal tensile stress and exposure time. Changes of capillary pore structure and phase compositions were measured using mercury intrusion porosimeter and X-ray diffraction, respectively. Unlike mortar, the fiber bridging of ECC helps with limiting crack width and thus the diffusion process, and the measured results were used to explain the observed penetration behavior of ECC. It is believed that the current study provides theoretical foundation for the durable design of the ECC/concrete composite structure.","Chloride penetration behavior; Engineered cementitious composites; Maximum normal tensile stress; Microcracks; Sustained flexural load","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-10-26","","","Materials and Environment","","",""
"uuid:0d808650-4e96-4a01-b69d-652b26ad7bfb","http://resolver.tudelft.nl/uuid:0d808650-4e96-4a01-b69d-652b26ad7bfb","Voltage Imaging with Engineered Proton-Pumping Rhodopsins: Insights from the Proton Transfer Pathway","Meng, X. (TU Delft ImPhys/Brinks group); Ganapathy, S. (TU Delft ImPhys/Brinks group; University of California); van Roemburg, Lars (Student TU Delft); Post, M.G. (TU Delft ImPhys/Brinks group); Brinks, D. (TU Delft ImPhys/Brinks group; Erasmus MC)","","2023","Voltage imaging using genetically encoded voltage indicators (GEVIs) has taken the field of neuroscience by storm in the past decade. Its ability to create subcellular and network level readouts of electrical dynamics depends critically on the kinetics of the response to voltage of the indicator used. Engineered microbial rhodopsins form a GEVI subclass known for their high voltage sensitivity and fast response kinetics. Here we review the essential aspects of microbial rhodopsin photocycles that are critical to understanding the mechanisms of voltage sensitivity in these proteins and link them to insights from efforts to create faster, brighter and more sensitive microbial rhodopsin-based GEVIs.","biosensors; fluorescence microscopy; genetically encoded voltage indicators; microbial rhodopsins; neuroscience; photophysics; protein engineering; proton transfer pathway","en","review","","","","","","","","","","","ImPhys/Brinks group","","",""
"uuid:8cf71cb1-40e5-4279-886f-d40dab9d2ffb","http://resolver.tudelft.nl/uuid:8cf71cb1-40e5-4279-886f-d40dab9d2ffb","Exciting Enzymes: Current State and Future Perspective of Photobiocatalysis","Alphand, Véronique (Aix Marseille University); van Berkel, Willem J.H. (Wageningen University & Research); Jurkaš, Valentina (Graz University of Technology); Kara, Selin (Aarhus University); Kourist, Robert (Graz University of Technology); Kroutil, Wolfgang (Universität Graz); Mascia, Francesco (Universidade do Porto); Nowaczyk, Marc M. (Universität Rostock); Paul, C.E. (TU Delft BT/Biocatalysis)","","2023","The recent increase of interest in photocatalysis spread to biocatalysis and triggered a rush for the development of light-dependent enzyme-mediated or enzyme-coupled processes. After several years of intense research on photobiocatalysis, it is time to evaluate the state of the field in a structured manner. In this Perspective, we suggest to group photobiocatalysis into distinct disciplines and provide principal guidelines and standards for the reporting of photobiocatalytic research results as well as advice on performing photobiocatalytic reactions. Overall, we assess that the field contributes to the diversity of biocatalytic reactions while offering the selectivity of enzymes to photocatalysis. We foresee that the ongoing excitement for light-dependent enzymatic processes will lead to the discovery of novel photobiocatalytic mechanisms to complement biocatalysis with new bond-forming reactions and will provide additional innovative strategies to utilize light as a possible benign energy source.","biocatalysis; cascade reactions; photoautotrophic organisms; photocatalysis; photoenzymes; reaction engineering","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:36d2123c-cfa6-40c6-92dc-4dcfbd96c501","http://resolver.tudelft.nl/uuid:36d2123c-cfa6-40c6-92dc-4dcfbd96c501","Impact of mean sea-level rise on the long-term evolution of a mega-nourishment","Ribas, Francesca (Universitat Politecnica de Catalunya); Portos-Amill, Laura (University of Twente); Falqués, Albert (Universitat Politecnica de Catalunya); Arriaga, Jaime (TU Delft Environmental Fluid Mechanics); Marcos, Marta (University of the Balearic Islands); Ruessink, Gerben (Universiteit Utrecht)","","2023","Mean sea-level rise (MSLR) will induce shoreline recession, increasing the stress on coastal systems of high socio-economic and environmental values. Localized mega-nourishments are meant to alleviate erosion problems by diffusing alongshore over decades and thus feeding adjacent beaches. The 21-st century morphological evolution of the Delfland coast, where the Sand Engine mega-nourishment was built in 2011, was simulated with the Q2Dmorfo model to assess the Sand Engine capacity to protect the area against the effects of MSLR. The calibrated and validated model was forced with historical wave and sea-level data and MSLR projections until 2100 corresponding to different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5). Results show that the Sand Engine diffusive trend will continue in forthcoming decades, with the feeding effect to adjacent beaches being less noticeable from 2050 onward. Superimposed to this alongshore diffusion, MSLR causes the shoreline to recede because of both passive-flooding and a net offshore sediment transport produced by wave reshaping and gravity. The existing feeding asymmetry enforces more sediment transport to the NE than to the SW, causing the former to remain stable whilst the SW shoreline retreats significantly, especially from 2050 onward. Sediment from the Sand Engine does not reach the beaches located more than 6 km to the SW, with a strong shoreline and profile recession in that area, as well as dune erosion. The uncertainties in the results are dominated by those related to the free model parameters up to 2050 whilst uncertainties in MSLR projections prevail from 2050 to 2100.","Climate change; Global warming; Mega-nourishment; Morphodynamic modelling; MSLR; Sand Engine","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:2e7c1d2a-3e4a-48ec-8df8-a663a77c389c","http://resolver.tudelft.nl/uuid:2e7c1d2a-3e4a-48ec-8df8-a663a77c389c","Characterisation of the E. coli HMS174 and BLR host cell proteome to guide purification process development","Disela, R.C. (TU Delft BT/Bioprocess Engineering); Bussy, Olivier Le (GSK Vaccines, Rixensart); Geldhof, Geoffroy (GSK Vaccines, Rixensart); Pabst, Martin (TU Delft BT/Environmental Biotechnology); Ottens, M. (TU Delft BT/Design and Engineering Education)","","2023","Mass-spectrometry-based proteomics is increasingly employed to monitor purification processes or to detect critical host cell proteins in the final drug substance. This approach is inherently unbiased and can be used to identify individual host cell proteins without prior knowledge. In process development for the purification of new biopharmaceuticals, such as protein subunit vaccines, a broader knowledge of the host cell proteome could promote a more rational process design. Proteomics can establish qualitative and quantitative information on the complete host cell proteome before purification (i.e., protein abundances and physicochemical properties). Such information allows for a more rational design of the purification strategy and accelerates purification process development. In this study, we present an extensive proteomic characterisation of two E. coli host cell strains widely employed in academia and industry to produce therapeutic proteins, BLR and HMS174. The established database contains the observed abundance of each identified protein, information relating to their hydrophobicity, the isoelectric point, molecular weight, and toxicity. These physicochemical properties were plotted on proteome property maps to showcase the selection of suitable purification strategies. Furthermore, sequence alignment allowed integration of subunit information and occurrences of post-translational modifications from the well-studied E. coli K12 strain.","bioprocess engineering; chromatography; e. coli; host cell proteomics; proteomics","en","journal article","","","","","","","","","","","BT/Bioprocess Engineering","","",""
"uuid:a1815d12-feb4-456b-9888-44f2ecb082ab","http://resolver.tudelft.nl/uuid:a1815d12-feb4-456b-9888-44f2ecb082ab","Large-eddy simulation of dual-fuel spray ignition at varying levels of methane diluted ambient oxidizer using FGM","Bao, Hesheng (Eindhoven University of Technology); Han, Jinlin (Eindhoven University of Technology); Zhang, Yan (CAEP Software Center for High Performance Numerical Simulation; Institute of Applied Physics and Computational Mathematics); Di Matteo, Andrea (Eindhoven University of Technology); Roekaerts, D.J.E.M. (TU Delft Fluid Mechanics); Van Oijen, Jeroen (Eindhoven University of Technology); Somers, Bart (Eindhoven University of Technology)","","2023","In the current work, the Flamelet Generated Manifold (FGM) method is applied with large-eddy simulation (LES) to investigate the effect of methane on dual-fuel (DF) spray ignition. The diesel surrogate n-dodecane is injected as the so-called pilot fuel into selected lean methane–air mixtures, ranging from ϕCH4=0 to ϕCH4=0.75, at engine relevant conditions. The operating conditions are those of the completely characterized Engine Combustion Network (ECN) Spray A configuration, for which the modeling approach adopted in the present study was extensively validated. The specific purpose of this study is to extend and validate the FGM approach for dual-fuel combustion. In order to understand the interplay of chemistry and mixing, the ignition behavior of selected cases is investigated. It is found that both low and high temperature combustion (LTC and HTC, respectively) are increasingly retarded by higher values of ϕCH4, while the induction time between LTC and HTC is relatively insensitive compared to the ignition delay time (IDT). Analysis reveals a more prominent role of mixing for increased ϕCH4. The development of LTC and HTC are quantitatively analyzed for different cases. The transition from LTC to HTC is found to be highly correlated with the evolution of lift-off length (LOL), which on its turn is seriously affected by ϕCH4. The local flame behavior is analyzed via chemical explosive mode analysis (CEMA), suggesting a clear flame propagation due to diffusion towards lean mixtures after the ignition of the pilot fuel. Besides, it is found that diffusion helps to stabilize the flame in leaner mixtures, which is more important in DF combustion. The results show FGM to be a promising tool in modeling the DF sprays.","Ambient methane concentration; Dual-fuel ignition; Engine Combustion Network; FGM; Large-eddy simulation; Spray A","en","journal article","","","","","","","","","","","Fluid Mechanics","","",""
"uuid:470ef79c-e772-4f36-bba8-cbf2209ae3d0","http://resolver.tudelft.nl/uuid:470ef79c-e772-4f36-bba8-cbf2209ae3d0","Assessment of expected production of a deep-sea mining system: An integrated model-based systems engineering and discrete event simulation approach","Solheim, Astrid V. (Norwegian University of Science and Technology (NTNU)); Rauzy, Antoine B. (Norwegian University of Science and Technology (NTNU)); Brett, Per Olaf (Norwegian University of Science and Technology (NTNU); Ulstein International A.S.); Ellefmo, Steinar (Norwegian University of Science and Technology (NTNU)); Hatling, Tonje (Norwegian University of Science and Technology (NTNU)); Helmons, R.L.J. (TU Delft Offshore and Dredging Engineering; Norwegian University of Science and Technology (NTNU)); Asbjørnslett, Bjørn Egil (Norwegian University of Science and Technology (NTNU))","","2023","In this paper, model-based systems engineering (MBSE) and discrete event simulation (DES) are combined to assess the performance of an offshore production system at an early stage. Various systems engineering tools are applied to an industrial case concerning the retrieval of deep-sea minerals, and a simulation engine is developed to calculate the annual production output. A mean production of 1 Million tonnes of ore per year is estimated for an operation in the Norwegian Sea using Monte Carlo simulation. Depending on the limiting design wave height of the marine operations, the estimated production output ranges from 280,000 tonnes to 1.8 Million tonnes per year. The constrained parameter of the production system is particularly the wave height operational limit of the ship-to-ship transfer operation. We present the learning outcome from applying MBSE and DES to this case and discuss important aspects for improved performance.","deep-sea mining; discrete event simulation; expected production; model-based systems engineering; Monte Carlo","en","journal article","","","","","","","","","","","Offshore and Dredging Engineering","","",""
"uuid:68d24b7f-ad4a-49b8-abff-108f576a1db7","http://resolver.tudelft.nl/uuid:68d24b7f-ad4a-49b8-abff-108f576a1db7","Three-dimensional localization microscopy with increased axial precision through TIRF angle modulation","Fan, D. (TU Delft Team Carlas Smith); Cnossen, J.P. (TU Delft Team Carlas Smith); Hung, S. (TU Delft Team Carlas Smith); Kromm, D. (TU Delft Support Delft Center for Systems and Control); Dekker, N.H. (TU Delft BN/Nynke Dekker Lab); Verbiest, G.J. (TU Delft Dynamics of Micro and Nano Systems); Smith, C.S. (TU Delft Team Carlas Smith)","","2023","To better understand the interactions between biological molecules, a high optical resolution in all three dimensions is crucial. The intrinsically lower axial resolution of microscopes however, is a limiting factor in fluorescence imaging, correspondingly in fluorescence based single molecule localization microscopy (SMLM). Here, we present a method to improve the axial localization precision in SMLM by combining point-spread-function engineering with total internal reflection fluorescence (TIRF) fields with decay lengths that vary within the on-time of a fluorophore. Such time-varying illumination field intensity allows one to extract additional axial location information from the emitted photons. With this time varying illumination approach, we show that axial localization is improved two-fold over TIRF-based SMLM using astigmatic PSFs. We calculate theoretical resolution gains for various imaging conditions via the Cramér Rao Lower Bound (CRLB), a commonly used metric to compute the best attainable localization precision in SMLM.","PSF engineering; Single molecule localization microscopy; Super-resolution microscopy; TIRF microscopy; Total internal reflection fluorescence","en","journal article","","","","","","","","","","","Team Carlas Smith","","",""
"uuid:91fb5f6e-910a-4997-bc0e-3b53a123b9f0","http://resolver.tudelft.nl/uuid:91fb5f6e-910a-4997-bc0e-3b53a123b9f0","Modulating design parameters to drive cell invasion into hydrogels for osteochondral tissue formation","Schwab, Andrea (Erasmus MC; AO Research Institute Davos, Davos); Wesdorp, Marinus A. (Erasmus MC); Xu, J. (Erasmus MC); Abinzano, Florencia (University Medical Center Utrecht); Loebel, Claudia (University of Pennsylvania); Levato, Riccardo (University Medical Center Utrecht; Universiteit Utrecht); Eglin, David (University of Twente; University Jean Monnet); Narcisi, Roberto (Erasmus MC); Malda, Jos (University Medical Center Utrecht; Universiteit Utrecht); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC)","","2023","Background: The use of acellular hydrogels to repair osteochondral defects requires cells to first invade the biomaterial and then to deposit extracellular matrix for tissue regeneration. Due to the diverse physicochemical properties of engineered hydrogels, the specific properties that allow or even improve the behaviour of cells are not yet clear. The aim of this study was to investigate the influence of various physicochemical properties of hydrogels on cell migration and related tissue formation using in vitro, ex vivo and in vivo models. Methods: Three hydrogel platforms were used in the study: Gelatine methacryloyl (GelMA) (5% wt), norbornene hyaluronic acid (norHA) (2% wt) and tyramine functionalised hyaluronic acid (THA) (2.5% wt). GelMA was modified to vary the degree of functionalisation (DoF 50% and 80%), norHA was used with varied degradability via a matrix metalloproteinase (MMP) degradable crosslinker and THA was used with the addition of collagen fibrils. The migration of human mesenchymal stromal cells (hMSC) in hydrogels was studied in vitro using a 3D spheroid migration assay over 48h. In addition, chondrocyte migration within and around hydrogels was investigated in an ex vivo bovine cartilage ring model (three weeks). Finally, tissue repair within osteochondral defects was studied in a semi-orthotopic in vivo mouse model (six weeks). Results: A lower DoF of GelMA did not affect cell migration in vitro (p = 0.390) and led to a higher migration score ex vivo (p < 0.001). The introduction of a MMP degradable crosslinker in norHA hydrogels did not improve cell infiltration in vitro or in vivo. The addition of collagen to THA resulted in greater hMSC migration in vitro (p = 0.031) and ex vivo (p < 0.001). Hydrogels that exhibited more cell migration in vitro or ex vivo also showed more tissue formation in the osteochondral defects in vivo, except for the norHA group. Whereas norHA with a degradable crosslinker did not improve cell migration in vitro or ex vivo, it did significantly increase tissue formation in vivo compared to the non-degradable crosslinker (p < 0.001). Conclusion: The modification of hydrogels by adapting DoF, use of a degradable crosslinker or including fibrillar collagen can control and improve cell migration and tissue formation for osteochondral defect repair. This study also emphasizes the importance of performing both in vitro and in vivo testing of biomaterials, as, depending on the material, the results might be affected by the model used. The translational potential of this article: This article highlights the potential of using acellular hydrogels to repair osteochondral defects, which are common injuries in orthopaedics. The study provides a deeper understanding of how to modify the properties of hydrogels to control cell migration and tissue formation for osteochondral defect repair. The results of this article also highlight that the choice of the used laboratory model can affect the outcome. Testing hydrogels in different models is thus advised for successful translation of laboratory results to the clinical application.","Cartilage; Cells; Hydrogels; Regenerative medicine; Tissue engineering","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:5d9c6679-4253-4453-8b8b-901832e88b86","http://resolver.tudelft.nl/uuid:5d9c6679-4253-4453-8b8b-901832e88b86","Auxeticity as a Mechanobiological Tool to Create Meta-Biomaterials","Yarali, E. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Staufer, U. (TU Delft Micro and Nano Engineering); Accardo, A. (TU Delft Micro and Nano Engineering); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics)","","2023","Mechanical and morphological design parameters, such as stiffness or porosity, play important roles in creating orthopedic implants and bone substitutes. However, we have only a limited understanding of how the microarchitecture of porous scaffolds contributes to bone regeneration. Meta-biomaterials are increasingly used to precisely engineer the internal geometry of porous scaffolds and independently tailor their mechanical properties (e.g., stiffness and Poisson's ratio). This is motivated by the rare or unprecedented properties of meta-biomaterials, such as negative Poisson's ratios (i.e., auxeticity). It is, however, not clear how these unusual properties can modulate the interactions of meta-biomaterials with living cells and whether they can facilitate bone tissue engineering under static and dynamic cell culture and mechanical loading conditions. Here, we review the recent studies investigating the effects of the Poisson's ratio on the performance of meta-biomaterials with an emphasis on the relevant mechanobiological aspects. We also highlight the state-of-the-art additive manufacturing techniques employed to create meta-biomaterials, particularly at the micrometer scale. Finally, we provide future perspectives, particularly for the design of the next generation of meta-biomaterials featuring dynamic properties (e.g., those made through 4D printing).","4D printing; additive manufacturing; auxeticity; bone tissue engineering; cell response; mechanobiology; Meta-biomaterials; Poisson's ratio","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:4d1ef391-16a9-4b7b-93b6-e032b2aab656","http://resolver.tudelft.nl/uuid:4d1ef391-16a9-4b7b-93b6-e032b2aab656","Hey Teachers, Teach Those Kids Some Software Testing","Ardıç, B.A. (TU Delft Software Engineering); Zaidman, A.E. (TU Delft Software Engineering)","O'Conner, Lisa (editor)","2023","Software testing is generally acknowledged to be an important weapon in the arsenal of software engineers to produce correct and reliable software systems. However, given the importance of the topic, little is known about where software engineers get their testing knowledge and skills from. Is this through (higher) education, training programmes in the industry, or rather is it self-taught? In this paper, we investigate the curricula of 100 highly ranked universities and survey 51 software engineers to shed light on the state-of-the-practice in software testing education, in terms of both academic education and education of software engineers in the industry.","education; software engineering; software testing","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-01-27","","","Software Engineering","","",""
"uuid:ae1da5ba-1673-49fb-8993-4330eed009fb","http://resolver.tudelft.nl/uuid:ae1da5ba-1673-49fb-8993-4330eed009fb","Guided Malware Sample Analysis Based on Graph Neural Networks","Chen, Yi Hsien (National Taiwan University); Lin, Si Chen (National Taiwan University); Huang, S. (TU Delft Organisation & Governance; National Yang Ming Chiao Tung University, Hsinchu); Lei, Chin Laung (National Taiwan University); Huang, Chun Ying","","2023","Malicious binaries have caused data and monetary loss to people, and these binaries keep evolving rapidly nowadays. With tons of new unknown attack binaries, one essential daily task for security analysts and researchers is to analyze and effectively identify malicious parts and report the critical behaviors within the binaries. While manual analysis is slow and ineffective, automated malware report generation is a long-term goal for malware analysts and researchers. This study moves one step toward the goal by identifying essential functions in malicious binaries to accelerate and even automate the analyzing process. We design and implement an expert system based on our proposed graph neural network called MalwareExpert. The system pinpoints the essential functions of an analyzed sample and visualizes the relationships between involved parts. We evaluate our proposed approach using executable binaries in the Windows operating system. The evaluation results show that our approach has a competitive detection performance (97.3% accuracy and 96.5% recall rate) compared to existing malware detection models. Moreover, it gives an intuitive and easy-to-understand explanation of the model predictions by visualizing and correlating essential functions. We compare the identified essential functions reported by our system against several expert-made malware analysis reports from multiple sources. Our qualitative and quantitative analyses show that the pinpointed functions indicate accurate directions. In the best case, the top 2% of functions reported from the system can cover all expert-annotated functions in three steps. We believe that the MalwareExpert system has shed light on automated program behavior analysis.","Graph neural network; machine learning for security; malware analysis; reverse engineering","en","journal article","","","","","","","","2023-12-07","","","Organisation & Governance","","",""
"uuid:a64a61ee-9037-49af-b38a-125e24210303","http://resolver.tudelft.nl/uuid:a64a61ee-9037-49af-b38a-125e24210303","Comparison of dredging, lanthanum-modified bentonite, aluminium-modified zeolite, and FeCl2 in controlling internal nutrient loading","Kang, Li (Wageningen University & Research); Haasler, Sina (University of Southern Denmark); Mucci, Maíra (Wageningen University & Research); Korving, Leon (Wetsus, Centre for Sustainable Water Technology); Dugulan, A.I. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RID/TS/Instrumenten groep); Prot, T.J.F. (Wetsus, Centre for Sustainable Water Technology); Waajen, Guido (Water Authority Brabantse Delta, Breda); Lürling, Miquel (Wageningen University & Research)","","2023","The eutrophic Bouvigne pond (Breda, The Netherlands) regularly suffers from cyanobacterial blooms. To improve the water quality, the external nutrient loading and the nutrient release from the pond sediment have to be reduced. An enclosure experiment was performed in the pond between March 9 and July 29, 2020 to compare the efficiency of dredging, addition of the lanthanum-modified bentonite clay Phoslock® (LMB), the aluminum-modified zeolite Aqual-P™ (AMZ) and FeCl2 to mitigate nutrient release from the sediment. The treatments improved water quality. Mean total phosphorus (TP) concentrations in water were 0.091, 0.058, 0.032, 0.031, and 0.030 mg P L-1 in controls, dredged, FeCl2, LMB and AMZ treated enclosures, respectively. Mean filterable P (FP) concentrations were 0.056, 0.010, 0.009, 0.005, and 0.005 mg P L-1 in controls, dredged, FeCl2, LMB and AMZ treatments, respectively. Total nitrogen (TN) and dissolved inorganic nitrogen (DIN) were similar among treatments; lanthanum was elevated in LMB treatments, Fe and Cl in FeCl2 treatments, and Al and Cl in AMZ treatments. After 112 days, sediment was collected from each enclosure, and subsequent sequential P extraction revealed that the mobile P pool in the sediments had reduced by 71.4%, 60.2%, 38%, and 5.2% in dredged, AMZ, LMB, and FeCl2 treatments compared to the controls. A sediment core incubation laboratory experiment done simultaneously with the enclosure experiment revealed that FP fluxes were positive in controls and cores from the dredged area, while negative in LMB, AMZ and FeCl2 treated cores. Dissolved inorganic nitrogen (DIN) release rate in LMB treated cores was 3.6 times higher than in controls. Overall, the applied in-lake treatments improved water quality in the enclosures. Based on this study, from effectiveness, application, stakeholders engagement, costs and environmental safety, LMB treatment would be the preferred option to reduce the internal nutrient loading of the Bouvigne pond, but additional arguments also have to be considered when preparing a restoration.","Geo-engineering techniques; Lake restoration; Nutrients; Sediment; Water quality","en","journal article","","","","","","","","","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:d6c6ffb4-38df-4b8c-8ac2-62b30150fa34","http://resolver.tudelft.nl/uuid:d6c6ffb4-38df-4b8c-8ac2-62b30150fa34","Simulated Design-Build-Test-Learn Cycles for Consistent Comparison of Machine Learning Methods in Metabolic Engineering","van Lent, P.H. (TU Delft Pattern Recognition and Bioinformatics); Schmitz, Joep (DSM); Abeel, T.E.P.M.F. (TU Delft Pattern Recognition and Bioinformatics; Broad Institute of MIT and Harvard)","","2023","Combinatorial pathway optimization is an important tool in metabolic flux optimization. Simultaneous optimization of a large number of pathway genes often leads to combinatorial explosions. Strain optimization is therefore often performed using iterative design-build-test-learn (DBTL) cycles. The aim of these cycles is to develop a product strain iteratively, every time incorporating learning from the previous cycle. Machine learning methods provide a potentially powerful tool to learn from data and propose new designs for the next DBTL cycle. However, due to the lack of a framework for consistently testing the performance of machine learning methods over multiple DBTL cycles, evaluating the effectiveness of these methods remains a challenge. In this work, we propose a mechanistic kinetic model-based framework to test and optimize machine learning for iterative combinatorial pathway optimization. Using this framework, we show that gradient boosting and random forest models outperform the other tested methods in the low-data regime. We demonstrate that these methods are robust for training set biases and experimental noise. Finally, we introduce an algorithm for recommending new designs using machine learning model predictions. We show that when the number of strains to be built is limited, starting with a large initial DBTL cycle is favorable over building the same number of strains for every cycle.","automated recommendation; combinatorial pathway optimization; DBTL cycles; machine learning; metabolic engineering","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:359d9a1e-b953-439e-a85e-bf7bb9108e94","http://resolver.tudelft.nl/uuid:359d9a1e-b953-439e-a85e-bf7bb9108e94","Fourth Annual Workshop on A/B Testing and Platform-Enabled Learning Research","Ritter, Steve (Carnegie Learning); Heffernan, Neil (Worcester Polytechnic Institute); Williams, Joseph Jay (University of Toronto); Lomas, J.D. (TU Delft Design Aesthetics); Bicknell, Klinton (Duolingo); Roschelle, Jeremy (Digital Promise); Motz, Ben (Indiana University - Purdue University); McNamara, Danielle (Arizona State University); Baraniuk, Richard (Rice University)","","2023","Learning engineering adds tools and processes to learning platforms to support improvement research. One kind of tool is A/B testing-common in large software companies and also represented academically at conferences like the Annual Conference on Digital Experimentation (CODE). A number of A/B testing systems focused on educational apps have arisen recently, including UpGrade and E-TRIALS. A/B testing can help improve educational platforms, yet challenging issues in education go beyond the generic paradigm. In response, a number of of digital learning platforms is opening their systems to learning-improvement research by instructors and/or third-party researchers, with specific supports necessary for education-specific research designs. This workshop will explore how A/B testing in educational contexts is different, how learning platforms are opening up new possibilities, and how these empirical approaches can be used to drive powerful gains in student learning. It will also discuss forthcoming opportunities for funding to conduct platform-enabled learning research.","A/B Testing; Digital Experimentation; Educational Technology; Learning Engineering","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Design Aesthetics","","",""
"uuid:1208be2a-9818-48d8-9d84-b0348fffa8e6","http://resolver.tudelft.nl/uuid:1208be2a-9818-48d8-9d84-b0348fffa8e6","Rational positioning of 3D-printed voxels to realize high-fidelity multifunctional soft-hard interfaces","Cruz Saldivar, M. (TU Delft Biomaterials & Tissue Biomechanics); Veeger, Robin Petrus Elias (Student TU Delft); Tay, E.T.W.S. (TU Delft Biomaterials & Tissue Biomechanics); Fenu, M. (TU Delft BN/Gijsje Koenderink Lab; Erasmus MC); Klimopoulou, M. (TU Delft Biomaterials & Tissue Biomechanics); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Doubrovski, E.L. (TU Delft Mechatronic Design); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2023","Living organisms use functional gradients (FGs) to interface hard and soft materials (e.g., bone and tendon), a strategy with engineering potential. Past attempts involving hard (or soft) phase ratio variation have led to mechanical property inaccuracies because of microscale-material macroscale-property nonlinearity. This study examines 3D-printed voxels from either hard or soft phase to decode this relationship. Combining micro/macroscale experiments and finite element simulations, a power law model emerges, linking voxel arrangement to composite properties. This model guides the creation of voxel-level FG structures, resulting in two biomimetic constructs mimicking specific bone-soft tissue interfaces with superior mechanical properties. Additionally, the model studies the FG influence on murine preosteoblast and human bone marrow-derived mesenchymal stromal cell (hBMSC) morphology and protein expression, driving rational design of soft-hard interfaces in biomedical applications.","bio-inspired composites; functional gradients; interface tissue engineering; regenerative medicine; soft-hard interfaces; voxel-by-voxel 3D printing","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:8290b1c6-96c9-4760-83b7-6997227fd350","http://resolver.tudelft.nl/uuid:8290b1c6-96c9-4760-83b7-6997227fd350","Rigid body dynamic response of a floating offshore wind turbine to waves: Identification of the instantaneous centre of rotation through analytical and numerical analyses","Patryniak, Katarzyna (University of Strathclyde); Collu, Maurizio (University of Strathclyde); Coraddu, A. (TU Delft Ship Design, Production and Operations)","","2023","Floating Offshore Wind Turbines (FOWT) can harness the abundant offshore wind resource at reduced installation requirements. However, a further decrease in the development risks through higher confidence in the design and analysis methods is needed. The dynamic behaviour of FOWT systems is complex due to the strong interactions between the large translational and rotational motions and the diverse loads, which poses a challenge. While the methods to study the FOWT's general responses are well established, there are no methods to describe the highly complex time-dependent rotational motion patterns of FOWT. For a rigid body in general plane motion, an Instantaneous Centre of Rotation (ICR) can be identified as a point at which, at a given moment, the velocity is zero. However, it is common to assume a centre of rotation fixed in space and time, arbitrarily set at the centre of floatation or gravity. Identification of the ICR is crucial as it may lead to better motion reduction methods and can be leveraged to improve the designs. This includes better-informed fairlead placement and the reduction of aerodynamic load variability. In this paper, we propose a two-fold approach for the identification of the ICR: an analytical solution in the initial static equilibrium position, and a time-domain numerical approach for dynamic analysis in regular and irregular waves to understand the motion patterns and ICR sensitivity to environmental conditions. Results show that the ICR of FOWT depends on wave frequency and, at low frequencies, on wave height, due to the nonlinear viscous drag and mooring loads. An unexpected but interesting result is that the surge-heave-pitch coupling introduced by the mooring system leads to a dynamic phenomenon of signal distortion known as ”clipping” in the nonlinear audio signal processing area, which, through the introduction of higher harmonics, is responsible for the ICR sensitivity to motion amplitude.","Coupled dynamics; Floating offshore wind turbine; Instantaneous centre of rotation; Nonlinear dynamics; Offshore engineering","en","journal article","","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:fdacfae6-9e40-4ff0-8349-92f4dc5a23ec","http://resolver.tudelft.nl/uuid:fdacfae6-9e40-4ff0-8349-92f4dc5a23ec","Micro-Vessels-Like 3D Scaffolds for Studying the Proton Radiobiology of Glioblastoma-Endothelial Cells Co-Culture Models","Akolawala, Q. (TU Delft Micro and Nano Engineering; Holland Particle Therapy Centre); Keuning, F.E. (Erasmus Universiteit Rotterdam); Rovituso, M. (Holland Particle Therapy Centre); van Burik, Wouter (Holland Particle Therapy Centre); van der Wal, E.M. (Holland Particle Therapy Centre); Versteeg, Henri H. (Leiden University Medical Center); Rondon, Araci M.R. (Leiden University Medical Center); Accardo, A. (TU Delft Micro and Nano Engineering)","","2023","Glioblastoma (GBM) is a devastating cancer of the brain with an extremely poor prognosis. While X-ray radiotherapy and chemotherapy remain the current standard, proton beam therapy is an appealing alternative as protons can damage cancer cells while sparing the surrounding healthy tissue. However, the effects of protons on in vitro GBM models at the cellular level, especially when co-cultured with endothelial cells, the building blocks of brain micro-vessels, are still unexplored. In this work, novel 3D-engineered scaffolds inspired by the geometry of brain microvasculature are designed, where GBM cells cluster and proliferate. The architectures are fabricated by two-photon polymerization (2PP), pre-cultured with endothelial cells (HUVECs), and then cultured with a human GBM cell line (U251). The micro-vessel structures enable GBM in vivo-like morphologies, and the results show a higher DNA double-strand breakage in GBM monoculture samples when compared to the U251/HUVECs co-culture, with cells in 2D featuring a larger number of DNA damage foci when compared to cells in 3D. The discrepancy in terms of proton radiation response indicates a difference in the radioresistance of the GBM cells mediated by the presence of HUVECs and the possible induction of stemness features that contribute to radioresistance and improved DNA repair.","endothelial cells; engineered cell microenvironments; glioblastoma; proton therapy; two-photon polymerization","en","journal article","","","","","","","","","","","Micro and Nano Engineering","","",""
"uuid:ffb8dbba-de6d-4be1-a474-68df56800b52","http://resolver.tudelft.nl/uuid:ffb8dbba-de6d-4be1-a474-68df56800b52","Design and thermodynamic analysis of a pathway enabling anaerobic production of poly-3-hydroxybutyrate in Escherichia coli","Olavarria, Karel (Wageningen University & Research; Eindhoven-Wageningen-Utrecht Alliance); Sousa, Diana Z. (Wageningen University & Research; Eindhoven-Wageningen-Utrecht Alliance); van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology); Wahl, S.A. (Friedrich-Alexander-Universität Erlangen-Nürnberg)","","2023","Utilizing anaerobic metabolisms for the production of biotechnologically relevant products presents potential advantages, such as increased yields and reduced energy dissipation. However, lower energy dissipation may indicate that certain reactions are operating closer to their thermodynamic equilibrium. While stoichiometric analyses and genetic modifications are frequently employed in metabolic engineering, the use of thermodynamic tools to evaluate the feasibility of planned interventions is less documented. In this study, we propose a novel metabolic engineering strategy to achieve an efficient anaerobic production of poly-(R)-3-hydroxybutyrate (PHB) in the model organism Escherichia coli. Our approach involves re-routing of two-thirds of the glycolytic flux through non-oxidative glycolysis and coupling PHB synthesis with NADH re-oxidation. We complemented our stoichiometric analysis with various thermodynamic approaches to assess the feasibility and the bottlenecks in the proposed engineered pathway. According to our calculations, the main thermodynamic bottleneck are the reactions catalyzed by the acetoacetyl-CoA β-ketothiolase (EC 2.3.1.9) and the acetoacetyl-CoA reductase (EC 1.1.1.36). Furthermore, we calculated thermodynamically consistent sets of kinetic parameters to determine the enzyme amounts required for sustaining the conversion fluxes. In the case of the engineered conversion route, the protein pool necessary to sustain the desired fluxes could account for 20% of the whole cell dry weight.","Anaerobic metabolism; Engineered pathways; Metabolite concentrations; Pathway feasibility analysis; Protein cost","en","journal article","","","","","","","","","","","BT/Environmental Biotechnology","","",""
"uuid:00e09703-652b-4aba-9f8f-b9725a16fc95","http://resolver.tudelft.nl/uuid:00e09703-652b-4aba-9f8f-b9725a16fc95","Into the Unknown: Exploration of Search Engines' Responses to Users with Depression and Anxiety","Milton, Ashlee (University of Minnesota Twin Cities); Pera, M.S. (TU Delft Web Information Systems)","","2023","Researchers worldwide have explored the behavioral nuances that emerge from interactions of individuals afflicted by mental health disorders (MHD) with persuasive technologies, mainly social media. Yet, there is a gap in the analysis pertaining to a persuasive technology that is part of their everyday lives: web search engines (SE). Each day, users with MHD embark on information seeking journeys using popular SE, like Google or Bing. Every step of the search process for better or worse has the potential to influence a searcher's mindset. In this work, we empirically investigate what subliminal stimulus SE present to these vulnerable individuals during their searches. For this, we use synthetic queries to produce associated query suggestions and search engine results pages. Then we infer the subliminal stimulus present in text from SE, i.e., query suggestions, snippets, and web resources. Findings from our empirical analysis reveal that the subliminal stimulus displayed by SE at different stages of the information seeking process differ between MHD searchers and our control group composed of ""average""SE users. Outcomes from this work showcase open problems related to query suggestions, search engine result pages, and ranking that the information retrieval community needs to address so that SE can better support individuals with MHD.","emotion; Mental health; sentiment; web search engines","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-05","","","Web Information Systems","","",""
"uuid:4b936c0e-21ac-4922-b4ce-45fa8a0e04ab","http://resolver.tudelft.nl/uuid:4b936c0e-21ac-4922-b4ce-45fa8a0e04ab","Growth, Distribution, and Photosynthesis of Chlamydomonas Reinhardtii in 3D Hydrogels","Oh, J.J. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft); Ammu, S.K. (TU Delft Aerospace Engineering); Vriend-Harwig, V.D. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft); Kieffer, R.Y. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft); Dr. Kleiner, F.K. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft); Balasubramanian, S. (TU Delft BN/Marie-Eve Aubin-Tam Lab; TU Delft Industrial Design Engineering; Kavli institute of nanoscience Delft); Karana, E. (TU Delft Emerging Materials); Masania, K. (TU Delft Aerospace Manufacturing Technologies); Aubin-Tam, M.E. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft)","","2023","Engineered living materials (ELMs) are a novel class of functional materials that typically feature spatial confinement of living components within an inert polymer matrix to recreate biological functions. Understanding the growth and spatial configuration of cellular populations within a matrix is crucial to predicting and improving their responsive potential and functionality. Here, this work investigates the growth, spatial distribution, and photosynthetic productivity of eukaryotic microalga Chlamydomonas reinhardtii (C. reinhardtii) in three-dimensionally shaped hydrogels in dependence of geometry and size. The embedded C. reinhardtii cells photosynthesize and form confined cell clusters, which grow faster when located close to the ELM periphery due to favorable gas exchange and light conditions. Taking advantage of location-specific growth patterns, this work successfully designs and prints photosynthetic ELMs with increased CO2 capturing rate, featuring high surface to volume ratio. This strategy to control cell growth for higher productivity of ELMs resembles the already established adaptations found in multicellular plant leaves.","3D printing; CO consumption; engineered living material; functional living surface; hydrogel; microalgae; spatial organization","en","journal article","","","","","","","","","Aerospace Engineering","","BN/Marie-Eve Aubin-Tam Lab","","",""
"uuid:6e4e2fa4-a04d-456d-8d63-17d3e9466d31","http://resolver.tudelft.nl/uuid:6e4e2fa4-a04d-456d-8d63-17d3e9466d31","Optoelectronic control of cardiac rhythm: Toward shock-free ambulatory cardioversion of atrial fibrillation","Portero, Vincent (Leiden University Medical Center); Deng, Shanliang (TU Delft Electronic Components, Technology and Materials; Leiden University Medical Center); Boink, Gerard J.J. (Universiteit van Amsterdam); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials); de Vries, Antoine (Leiden University Medical Center); Pijnappels, Daniël A. (Leiden University Medical Center)","","2023","Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, progressive in nature, and known to have a negative impact on mortality, morbidity, and quality of life. Patients requiring acute termination of AF to restore sinus rhythm are subjected to electrical cardioversion, which requires sedation and therefore hospitalization due to pain resulting from the electrical shocks. However, considering the progressive nature of AF and its detrimental effects, there is a clear need for acute out-of-hospital (i.e., ambulatory) cardioversion of AF. In the search for shock-free cardioversion methods to realize such ambulatory therapy, a method referred to as optogenetics has been put forward. Optogenetics enables optical control over the electrical activity of cardiomyocytes by targeted expression of light-activated ion channels or pumps and may therefore serve as a means for cardioversion. First proof-of-principle for such light-induced cardioversion came from in vitro studies, proving optogenetic AF termination to be very effective. Later, these results were confirmed in various rodent models of AF using different transgenes, illumination methods, and protocols, whereas computational studies in the human heart provided additional translational insight. Based on these results and fueled by recent advances in molecular biology, gene therapy, and optoelectronic engineering, a basis is now being formed to explore clinical translations of optoelectronic control of cardiac rhythm. In this review, we discuss the current literature regarding optogenetic cardioversion of AF to restore normal rhythm in a shock-free manner. Moreover, key translational steps will be discussed, both from a biological and technological point of view, to outline a path toward realizing acute shock-free ambulatory termination of AF.","atrial fibrillation; cardiology; cardioversion; engineering; optogenetics; treatments","en","review","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:03e6f046-787e-44f3-8355-d13617122d47","http://resolver.tudelft.nl/uuid:03e6f046-787e-44f3-8355-d13617122d47","Co-cultivation of Saccharomyces cerevisiae strains combines advantages of different metabolic engineering strategies for improved ethanol yield","van Aalst, A.C.A. (TU Delft BT/Industriele Microbiologie); van der Meulen, Igor S. (Student TU Delft); Jansen, Mickel L.A. (DSM); Mans, R. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie)","","2023","Glycerol is the major organic byproduct of industrial ethanol production with the yeast Saccharomyces cerevisiae. Improved ethanol yields have been achieved with engineered S. cerevisiae strains in which heterologous pathways replace glycerol formation as the predominant mechanism for anaerobic re-oxidation of surplus NADH generated in biosynthetic reactions. Functional expression of heterologous phosphoribulokinase (PRK) and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) genes enables yeast cells to couple a net oxidation of NADH to the conversion of glucose to ethanol. In another strategy, NADH-dependent reduction of exogenous acetate to ethanol is enabled by introduction of a heterologous acetylating acetaldehyde dehydrogenase (A-ALD). This study explores potential advantages of co-cultivating engineered PRK-RuBisCO-based and A-ALD-based strains in anaerobic bioreactor batch cultures. Co-cultivation of these strains, which in monocultures showed reduced glycerol yields and improved ethanol yields, strongly reduced the formation of acetaldehyde and acetate, two byproducts that were formed in anaerobic monocultures of a PRK-RuBisCO-based strain. In addition, co-cultures on medium with low acetate-to-glucose ratios that mimicked those in industrial feedstocks completely removed acetate from the medium. Kinetics of co-cultivation processes and glycerol production could be optimized by tuning the relative inoculum sizes of the two strains. Co-cultivation of a PRK-RuBisCO strain with a Δgpd1 Δgpd2 A-ALD strain, which was unable to grow in the absence of acetate and evolved for faster anaerobic growth in acetate-supplemented batch cultures, further reduced glycerol formation but led to extended fermentation times. These results demonstrate the potential of using defined consortia of engineered S. cerevisiae strains for high-yield, minimal-waste ethanol production.","Acetate reduction; Bioethanol; Co-cultures; PRK-RuBisCO; Redox-engineering; Synthetic microbial consortia","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:d4e08e5c-1fae-4d83-8294-e096e6b455d9","http://resolver.tudelft.nl/uuid:d4e08e5c-1fae-4d83-8294-e096e6b455d9","Miniaturized engineered heart tissues from hiPSC-derived triple cell type co-cultures to study human cardiac function","Windt, L. M. (Leiden University Medical Center); Wiendels, M. (Leiden University Medical Center); Dostanić, M. (Leiden University Medical Center); Bellin, M. (Leiden University Medical Center; Università degli Studi di Padova; Veneto Institute of Molecular Medicine); Sarro, Pasqualina M (TU Delft Electronic Components, Technology and Materials); Mastrangeli, Massimo (TU Delft Electronic Components, Technology and Materials); Mummery, C. L. (Leiden University Medical Center); van Meer, B.J. (TU Delft Electronic Components, Technology and Materials; Leiden University Medical Center; Sync Biosystems)","","2023","Human heart tissues grown as three-dimensional spheroids and consisting of different cardiac cell types derived from pluripotent stem cells (hiPSCs) recapitulate aspects of human physiology better than standard two-dimensional models in vitro. They typically consist of less than 5000 cells and are used to measure contraction kinetics although not contraction force. By contrast, engineered heart tissues (EHTs) formed around two flexible pillars, can measure contraction force but conventional EHTs often require between 0.5 and 2 million cells. This makes large-scale screening of many EHTs costly. Our goals here were (i) to create a physiologically relevant model that required fewer cells than standard EHTs making them less expensive, and (ii) to ensure that this miniaturized model retained correct functionality. We demonstrated that fully functional EHTs could be generated from physiologically relevant combinations of hiPSC-derived cardiomyocytes (70%), cardiac fibroblasts (15%) and cardiac endothelial cells (15%), using as few as 1.6 × 104 cells. Our results showed that these EHTs were viable and functional up to 14 days after formation. The EHTs could be electrically paced in the frequency range between 0.6 and 3 Hz, with the optimum between 0.6 and 2 Hz. This was consistent across three downscaled EHT sizes tested. These findings suggest that miniaturized EHTs could represent a cost-effective microphysiological system for disease modelling and examining drug responses particularly in secondary screens for drug discovery.","Cardiac contraction; Cardiomyocytes; Engineered heart tissues; hiPSCs; Microphysiological system","en","journal article","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:795f85a7-6160-4403-9c0f-8465942ec892","http://resolver.tudelft.nl/uuid:795f85a7-6160-4403-9c0f-8465942ec892","Physics Engine-Based Whole-Hand Haptic Rendering for Sensorimotor Neurorehabilitation","Ratz, Raphael (University of Bern); Marchal Crespo, L. (TU Delft Human-Robot Interaction; Erasmus MC; University of Bern)","","2023","Whole-hand haptic rendering could lead to more naturalistic and intuitive virtual hand-object interactions, which could be especially beneficial for applications such as sensorimotor robotic neurorehabilitation. However, the majority of previously proposed whole-hand haptic rendering algorithms rely on effortful custom implementations or are not suited for the grounded haptic devices often used in neurorehabilitation. Therefore, we suggest a framework for whole-hand haptic rendering based on a readily available physics engine. We employ a bilateral position-position teleoperation framework between a haptic rehabilitation device and a simulated hand avatar with added exercise-specific haptic rendering. Moreover, in consideration of the needs of neurological patients, we introduce an adaptive damping of the haptic device during hand-object interactions for increased stabilization of the patient's limb. We present the first results of the feasibility of the proposed framework in a haptic rehabilitation exercise. In an ongoing clinical study, the practical application of the presented framework is currently investigated.","grasping; hand; Haptics; neurorehabilitation; physics engine","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-25","","","Human-Robot Interaction","","",""
"uuid:b0a752b0-7cd5-41a2-861a-4c51434582a5","http://resolver.tudelft.nl/uuid:b0a752b0-7cd5-41a2-861a-4c51434582a5","A high-resolution record of surface melt on Antarctic ice shelves using multi-source remote sensing data and deep learning","de Roda Husman, S. (TU Delft Physical and Space Geodesy); Lhermitte, S.L.M. (TU Delft Mathematical Geodesy and Positioning; Katholieke Universiteit Leuven); Bolibar, J. (TU Delft Physical and Space Geodesy); Izeboud, M. (TU Delft Mathematical Geodesy and Positioning); Hu, Zhongyang (Universiteit Utrecht); Shukla, S. (TU Delft Physical and Space Geodesy); van der Meer, Marijn (ETH Zürich); Long, David (Brigham Young University); Wouters, B. (TU Delft Physical and Space Geodesy)","","2023","While the influence of surface melt on Antarctic ice shelf stability can be large, the duration and affected area of melt events are often small. Therefore, melt events are difficult to capture with remote sensing, as satellite sensors always face the trade-off between spatial and temporal resolution. To overcome this limitation, we developed UMelt: a surface melt record for all Antarctic ice shelves with a high spatial (500 m) and high temporal (12 h) resolution for the period 2016–2021. Our approach is based on a deep learning model, specifically a U-Net, which was developed in Google Earth Engine. The U-Net combines microwave remote sensing observations from three sources: Sentinel-1, Special Sensor Microwave Imager/Sounder (SSMIS), and Advanced Scatterometer (ASCAT). The U-Net was trained on the Shackleton Ice Shelf for melt seasons 2017–2021, using the fine-scale melt patterns of Sentinel-1 as reference data and SSMIS, ASCAT, a digital elevation model, and multi-year Sentinel-1 melt fraction as predictors. The trained U-Net performed well on the Shackelton Ice Shelf for test melt season 2016–2017 (accuracy: 91.3%; F1-score: 86.9%), and the Larsen C Ice Shelf, which was not considered during training (accuracy: 91.0%; F1-score: 89.3%). Using the trained U-Net model, we have successfully developed the UMelt record. UMelt allows Antarctic-wide surface melt to be detected at a small scale while preserving a high temporal resolution, which could lead to new insights into the response of ice shelves to a changing atmospheric forcing.","Antarctica; Enhanced resolution; Google Earth Engine; Machine learning; Microwave remote sensing; Surface melt; U-Net","en","journal article","","","","","","","","","","","Physical and Space Geodesy","","",""
"uuid:48b4289c-321d-4b7d-8904-18e405d50255","http://resolver.tudelft.nl/uuid:48b4289c-321d-4b7d-8904-18e405d50255","Ethics of socially disruptive technologies: An introduction","van de Poel, I.R. (TU Delft Ethics & Philosophy of Technology); Frank, Lily Eva (Eindhoven University of Technology); Hermann, Julia (University of Twente); Hopster, Jeroen (Universiteit Utrecht); Lenzi, Dominic (University of Twente); Nyholm, Sven (Ludwig Maximilians University); Taebi, B. (TU Delft Ethics & Philosophy of Technology); Ziliotti, E. (TU Delft Ethics & Philosophy of Technology)","","2023","Technologies shape who we are, how we organize our societies and how we relate to nature. For example, social media challenges democracy; artificial intelligence raises the question of what is unique to humans; and the possibility to create artificial wombs may affect notions of motherhood and birth. Some have suggested that we address global warming by engineering the climate, but how does this impact our responsibility to future generations and our relation to nature? This book shows how technologies can be socially and conceptually disruptive and investigates how to come to terms with this disruptive potential. Four technologies are studied: social media, social robots, climate engineering and artificial wombs. The authors highlight the disruptive potential of these technologies, and the new questions this raises. The book also discusses responses to conceptual disruption, like conceptual engineering, the deliberate revision of concepts.","Artificial intelligence; Artificial wombs; Climate engineering; Social media; Social robots; Society; Technology","en","book","Open Book Publishers","9781805110170","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:aabf36b1-ad0b-4c6f-af69-90331fddc6a2","http://resolver.tudelft.nl/uuid:aabf36b1-ad0b-4c6f-af69-90331fddc6a2","Self-Supervised Learning for Enhancing Angular Resolution in Automotive MIMO Radars","Roldan Montero, I. (TU Delft Microwave Sensing, Signals & Systems); Fioranelli, F. (TU Delft Microwave Sensing, Signals & Systems); Yarovoy, Alexander (TU Delft Microwave Sensing, Signals & Systems)","","2023","A novel framework to enhance the angular resolution of automotive radars is proposed. An approach to enlarge the antenna aperture using artificial neural networks is developed using a self-supervised learning scheme. Data from a high angular resolution radar, i.e., a radar with a large antenna aperture, is used to train a deep neural network to extrapolate the antenna element's response. Afterward, the trained network is used to enhance the angular resolution of compact, low-cost radars. One million scenarios are simulated in a Monte-Carlo fashion, varying the number of targets, their Radar Cross Section (RCS), and location to evaluate the method's performance. Finally, the method is tested in real automotive data collected outdoors with a commercial radar system. A significant increase in the ability to resolve targets is demonstrated, which can translate to more accurate and faster responses from the planning and decision-making system of the vehicle.","angular resolution; Antenna arrays; Automotive engineering; automotive radar; machine learning; MIMO; MIMO radar; neural networks; Radar; Radar antennas; Radar cross-sections; radar signal processing; Receiving antennas","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-19","","","Microwave Sensing, Signals & Systems","","",""
"uuid:769d3d81-8a84-4f59-80a6-2d237aa878a4","http://resolver.tudelft.nl/uuid:769d3d81-8a84-4f59-80a6-2d237aa878a4","Recommender Systems for DevOps","Maddila, C.S. (TU Delft Software Engineering)","van Deursen, A. (promotor); Nagappan, Nachiappan (promotor); Gousios, G. (promotor); Delft University of Technology (degree granting institution)","2022","The software development life cycle (SDLC) for a developer has increased in complexity and scale. With the advent of DevOps processes, the gap between development and operations teams reduced significantly. Developers are now expected to perform different roles from coding to operational support in the new model of software development. This shift demands the evolution and improvement of software development practices and deliver products at a faster pace than organizations using traditional software development and infrastructure management processes. As a consequence, the demand for more intelligent and context sensitive DevOps tools and services that help developers increase their efficiency is increasing. A lot of research went into developing recommenders for DevOps, by leveraging the advancements made by the recommender system community. However, a lot of existing tools still work in ‘silos’ and does not take into account a holistic view of DevOps processes and the data generated at phase of the DevOps lifecycle while making recommendations.
By contrast, in this thesis, we propose a unified framework to develop recommenders for DevOps: perform data collection, building the models, deploying them, and evaluating the effectiveness of such recommenders in large-scale cloud development environments quickly and efficiently. We study the effect of such recommenders on the DevOps processes by performing empirical research and mixed method approaches (qualitative and quantitative analyses) on each of the deployed recommenders to better understand the productivity gains and the impact created by them.
Our results show that developers benefit greatly from smart recommenders such as Nudge, ConE, Orca, and MyNalanda. We also show, through rigorous experiments, technical action research methods, and empirical analyses that these recommenders provide as much as 65% gains in terms of change progression and 73% accuracy for root causing the service incidents automatically. We also conduct large scale surveys and interviews to support our empirical analysis and quantitative results. Our unified data framework and the platform we developed for building these recommenders is generic enough and encourages reusability of vital functions of such recommenders systems, such as data collection, model training, inference, deployment, and evaluation.","DevOps; Recommender Systems; Artificial Intelligence; Machine learning (ML); Software Engineering; Programming Languages","en","doctoral thesis","","","","","","","","","","","Software Engineering","","",""
"uuid:6d76d0e3-18ea-4fad-821f-2267262172ac","http://resolver.tudelft.nl/uuid:6d76d0e3-18ea-4fad-821f-2267262172ac","Hindcasting of levee failures: Deterministic and probabilistic methods","Kool, J.J. (TU Delft Hydraulic Structures and Flood Risk)","Jonkman, Sebastiaan N. (promotor); Jommi, C. (promotor); Kanning, W. (copromotor); Delft University of Technology (degree granting institution)","2022","In the last century, approximately 100,000 people lost their lives during a flood event and over 1.4 billion people were affected. As the population and economic activities grow in flood-prone areas and the frequencies and intensities of flood events increase due to climate change, damage due to flooding is expected to increase. To limit and control the potentially increased risks, in many locations flood defences, such as levees, are built and existing flood defences are reinforced. It is thus important to be able to properly estimate the reliability of these levees and to understand their potential failure mechanisms. In particular, there are significant uncertainties associated with the occurrence of geotechnical failure mechanisms such as slope instability and piping.
The hindcasting of levee failures can provide valuable information about the factors and uncertainties that dominate levee performance and reliability. Systematic forensic engineering approaches to evaluate failed structures and methods of hindcasting have been developed in the field of structural engineering, but these are not well applicable to failed levees. This is mostly due to the scarcity of relevant information prior to, during or after the levee failure, which leaves multiple scenarios and alternative model choices possible to characterize the event.
This thesis proposes and demonstrates methods for systematic analysis of levee failures at the individual section and system level. These methods of hindcasting are expected to contribute to the overall quality, repeatability, transferability, transparency and recognisability of the analysis of levee failures. In this thesis, existing approaches for evaluating structural failures have been adapted to analyse levee failures using both deterministic and probabilistic techniques. This thesis focuses on the levee failure mechanism of slope instability of the inner slope.
Firstly a deterministic method is proposed which is applied to a slope failure. In this method, the uncertainties in possible causes and computational models are modelled by defining possible scenarios explaining the failure based on all the information available. The influence of the identified scenarios and possible alternatives in model choices are analysed through a sensitivity analysis. Results of the computations are confirmed or refuted by observation information of the failure such as the shape of the failure surface. To illustrate the method, it is applied to the levee failure near Breitenhagen (2013), in Germany in Chapter 2 of this dissertation. The levee near Breitenhagen is located at the intersection of the Saale and the Elbe and it failed due to instability of the slope at the polder side of the levee. Unexpected saturation of the levee, steep slope of the levee, and the influence of the tree roots were identified to cause of the levee failure by previous reports. However, in the present study, an old breach was found to be there (the first proxy was a pond likely caused by this old breach next to the levee; the old breach was later confirmed with archive research). This old breach and pond resulted in a scenario with low strength and high water pressures in both levee and the aquifer and was identified to be the most likely scenario explaining the failure. The results indicate that locally low values of shear strength (low values of pre-overburden pressure or cohesion) explain the failure. Other scenarios that were evaluated resulted in a situation that was not likely to fail or, resulted in a slip surface that differs from the observed failure surface.
The deterministic method does not quantify uncertainties explicitly. That makes it difficult to uniquely identify the most likely scenario to explain the failure. Therefore the deterministic method is advanced by making it probabilistic and by including Bayesian techniques in Chapter 3. Thereby a better insight is provided into the relative likelihoods of the various scenarios explaining the failure. Failure observations (water level at failure, the shape of the slip surface, etc.) and a-priori levee information (soil layering, shear strength etc) are systematically taken into account to quantitatively identify the most likely scenario explaining the failure and the most representative model choices to most accurately characterise the failure. The Bayesian techniques are also used for updating the scenario and possible alternatives in model choices using the observations of the actual failure (if present) such as the shape of the slip surface. To illustrate the method, it is also applied to the levee failure near Breitenhagen (2013) in Germany. Similar to the deterministic method, the old breach resulting in a scenario with locally weak soil and aquifer connection is found to be the most likely scenario. Further, the Limit equilibrium using Spencer’s approach and undrained soil response is identified to be the most representative model choices. The shear strength ratio is identified as the 6 most dominant contributor to the failure. Compared to the “deterministic method” introduced in chapter 2, the probabilistic method adds the possibility to quantitatively substantiate the identification of the most likely scenario explaining the failure as well as the most representative model choices.
Both methods of hindcasting have had little application and validation. Therefore both methods have been applied to a large-scale levee failure experiment. The levee of the Leendert de Boerpolder, in the Netherlands, was brought to failure under controlled circumstances. As a result, very detailed information is available. The levee was brought to failure by gradually lowering the water level in an excavated ditch at the polder side of the levee. Since the water level drawdown is known at the time of failure, this information is used to validate the outcome of both methods of hindcasting. The available levee information was used in two steps. In the first instance, only basic information was used in the hindcasting. In the second step, the geometry of the observed slip surface is also included. The probabilistic method using Bayesian techniques required some adjustment, to account for the survival of previous load phases during a stepwise increase of the load. Both methods of hindcasting identified the same water level drawdown at the moment of failure, but different model choices. In addition, the identified water level drawdown is confirmed by the observed water level drawdown at the time of the failure, i.e. 1.6 m.
Finally, this thesis introduces a method to quantify the influence of deviating conditions on the failure rate of a levee by looking at failures on a system level. The annual failure rate of a levee section is assessed based on information from historical floods. The return period of past events is also taken into account. The presence of deviating conditions at failed and survived levee sections is analysed based on satellite observations. Bayesian techniques and likelihood ratios are used to update the average failure rate as a function of the presence of a deviation. The river system of Sachsen-Anhalt, Germany, is used as a case study. It experienced severe floods with many levee failures in the years 2002 and 2013 resulting in the failure of 41 levee sections due to internal erosion, instability or overflow. It is found that the presence of geological deviations has a significant influence on the observed failure rate and that the failure rate increases with the magnitude of the hydraulic loading. The results show that in the case of the occurrence of a visually identifiable geological deviation in the subsurface, the updated failure rate of a section is about 14 times high than when there is no visually identifiable deviation. The presence of other deviations, such as bushes or trees, or permanent water near the levee also results in a somewhat higher failure rate (20–30% higher) than the calculated average annual failure rate. It is also discussed how the expected number of failures in a system during a high water event with a certain magnitude can be estimated. The results of this research can be used to further optimize soil investigations, calibrate the results of more advanced reliability analyses, and complement risk assessments. The method offers opportunities in particular in environments where little data is available.
Overall, the methods and insights developed in this thesis can contribute to a better understanding of the performance and reliability of flood defence systems.","Hindcasting; Back analysis; Forensic engineering; River levee; Slope instability; Levee failures; Bayesian techniques; Failure rate; Likelihood ratio; Fragility curve","en","doctoral thesis","","978-94-6469-161-0","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:9f1481f0-5917-481d-8aa8-c52f846492cf","http://resolver.tudelft.nl/uuid:9f1481f0-5917-481d-8aa8-c52f846492cf","Policies, applications, barriers and future trends of building information modeling technology for building sustainability and informatization in China","Xie, Mingjing (Central South University China); Qiu, Yangzi (Central South University China); Liang, Yishuang (Central South University China); Zhou, Yuekuan (The Hong Kong University of Science and Technology; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute); Liu, Zhengxuan (TU Delft Design & Construction Management; Central South University China; Hunan University); Zhang, Guoqiang (Hunan University)","","2022","The application of building information modeling (BIM) technology has effectively supported the high-quality development of building sustainability and informatization in China. However, few studies comprehensively analyzed the enacted policies, prevalent applications, and existing barriers of the latest application and development of BIM technology in building industry from building sustainability and informatization perspectives to provide effective consultation and guidelines for its rational scale application in China. This paper firstly made a statistical analysis on the policies and standards of BIM technology issued from 2011 to 2021 in China. Moreover, the latest application, development and existing issues of BIM technology in building sustainability and informatization were also comprehensively discussed and analyzed. The main conclusions indicated that the application status of BIM technology for building sustainability and informatization in China was large in quantity, wide in scope, but low in level. The existing issue and limitation in terms of BIM application in China was mainly due to the lack of standards and domestic-oriented tools. Finally, the future outlook and recommendations of BIM technology for building sustainability and informatization in China were also presented as avenues for upcoming research.","Building information modeling; Building informatization; Building sustainability; Engineering management; Sustainable development","en","review","","","","","","","","","","","Design & Construction Management","","",""
"uuid:c7c9260b-96af-4faa-9bf8-00d115200ac9","http://resolver.tudelft.nl/uuid:c7c9260b-96af-4faa-9bf8-00d115200ac9","Towards a composite exhaust system: Investigation of the flow, thermal and wear resistance of an insulating, ceramic fibrous liner of combustion engine exhaust ducts and their influence on the design space","Reurings, C. (TU Delft Structural Integrity & Composites)","Benedictus, R. (promotor); Koussios, S. (copromotor); Delft University of Technology (degree granting institution)","2022","The current concerns regarding global warming and climate change in Europe and other parts of the world also influence developments in the automotive sector. Not only are alternative energy and power sources making their advent, but greenhouse gas emission reduction has also become a major factor in the development of vehicles with combustion engines. As passenger vehicles with such engines will be sold for probably a few more decades, additional options for emission reduction are still welcome. Mass reduction results directly in less greenhouse gas emission per driven kilometer, both in practice as in the official carbon dioxide (CO2) emission determination procedures.
This thesis is part of a project that tries to develop an additional option for passenger vehicle mass reduction, more specifically by replacing steel in the exhaust system with fibrereinforced plastic. The principle behind this solution is that fibrereinforced plastic has better mechanical properties per kilogram of material than steel. Yet, no plastic could endure direct exposure to exhaust gas flows because of the maximum gas temperature of 800 1000 ∘C....
The instability-induced spiral vortices on rotating aero-engine-nose-cones are expected to influence the aerodynamics at the fan root. This will potentially affect the loss mechanism at junctions between fan blades and the hub (the central rotating body of the engine, including the nose-cone). Accurate assessment of these losses requires knowing the boundary-layer instability behaviour on rotating cones in aero-engine-like flow conditions.
The past literature on this classical instability problem has only focused on low-speed (low-Reynolds number incompressible) axisymmetric inflow conditions. In reality, aero-engine-nose-cones often experience high-speed (high-Reynolds number compressible) inflow during a cruise. Moreover, several concepts of future-aircraft feature engines embedded in the airframe, or engines with ultra high bypass ratio with short nacelles. Owing to the associated inflow distortions, the nose-cones of these engines will experience non-axisymmetric inflow. However, limitations of the past experimental techniques pose hurdles in investigating the boundary-layer instability on rotating cones in non-axisymmetric as well as high-speed inflows.
This dissertation explores the boundary-layer instability on rotating cones with the inflow conditions pertaining to a typical aero-engine, i.e. non-axisymmetric as well as high-speed inflow. First, an experimental method is developed to measure the coherent flow structures on rotating cones. This method uses infrared thermography (IRT) with proper orthogonal decomposition (POD) to detect the thermal footprints of the spiral vortices on rotating cones. The POD modes are selectively used to reconstruct different instability-induced flow features. For this selection, a new criterion is formulated to determine the physical admissibility of the POD modes for reconstructing the flow-feature of interest. This method overcomes the limitations of the past experimental methods and has allowed quantitative measurements of spiral vortex growth, angle and azimuthal number, for the first time in complex flow environment, i.e. axial as well as non-axial inflow and high-speed inflow.
The asymmetry of the non-axial inflow has been found to delay the spiral vortex growth on the investigated case of a rotating slender cone (half-cone angle ψ=15º). Here, the spiral vortex growth appears at higher local Reynolds number Rel and local rotational speed ratio S compared to the axial inflow case at same operating conditions. It is postulated that the azimuthal asymmetry of the flow conditions (local Rel and S) disturbs the azimuthal coherence of the instability characteristics, i.e. angle and wavelength of the dominant mode. This inhibits the spiral vortex growth. However, at high rotational speed ratio S, when the instability characteristics approach the azimuthal coherence, the spiral vortices are found to be growing in the asymmetric flow field.
Furthermore, the dissertation extends the axial flow investigations from the most addressed case of a rotating slender cone of ψ=15º to the broader cones of ψ=22.5º, 30º, 45º, and 50º. Here, the boundary-layer instability mechanism changes from the centrifugal instability for slender cones ψ ≤ 30º to the cross-flow instability for the broad cones ψ ≥ 30º. The exact half-cone angle where this change occurs still remains unclear. While the past literature majorly focused on rotating slender cones in axial inflow, theoretical studies expressed the lack of experimental data for the rotating broad cones in axial inflow. This dissertation has provided this experimental data on the instability-induced spiral vortices for the rotating broad cones of ψ=45º and 50º in axial inflow.
The experimental method developed in this work has enabled studying the boundary-layer instability behaviour on rotating cones, for the first time in high-speed conditions, i.e. local Reynolds number Rel =0—3 × 106, rotational speed ratio S<1—1.5, and inflow Mach number M=0.5. These conditions are typically expected on the aero-engine-nose-cones during the transonic cruise of a large passenger aircraft (like A320, A350, etc.). These high-speed measurements revealed that the spiral vortices grow on the investigated rotating cones (ψ=15º, 30º and 40º) as expected from the low-speed studies. This confirms that the right circular type nose-cones of the transonic cruise aircraft will experience the spiral vortex growth in transitional boundary-layer.
The dissertation also conceptually discusses the potential effects of the spiral vortices on the fan aerodynamics. The spiral vortices are expected to influence the aerodynamics within the blade passage, especially, near the hub. Flow at the hub and fan-blade junction corner often separates on the suction side of the blade. This reduces the total pressure rise and efficiency of the engine. Presence of the spiral vortices is expected to affect the local aerodynamics at the hub, including the hub-corner separation, however, quantifying this effect needs further investigation. Furthermore, the dissertation has also shown a typical asymmetric flow field around the nose-cones when the fan is subjected to an inflow distortion. The fan-driven redistribution of the distorted inflow reduces the flow-field asymmetry near the nose-cone wall in the symmetry plane. This is a favourable condition for the spiral vortex growth.
Overall, this doctoral research has presented a new experimental approach to the classical problem of the boundary-layer instability on rotating cones. This has allowed furthering the fundamental knowledge about the instability-induced spiral vortex growth on rotating cones in following parameters: local Reynolds number Rel =0—3 × 106, rotational speed ratio S=0—250, inflow Mach number M=0—0.5, inflow incidence angle α=0º—10º and half-cone angle ψ=15º—50º.","Boundary layer instability; Boundary layer transition; Rotating boundary layers; Rotating cones; Experimental methods; Aero-engine nose-cones; Fan under distorted inflow","en","doctoral thesis","","978-94-6384-289-1","","","","","","","","","Flight Performance and Propulsion","","",""
"uuid:442e4cce-37f5-4e7a-a633-badee05ae0e3","http://resolver.tudelft.nl/uuid:442e4cce-37f5-4e7a-a633-badee05ae0e3","PropR: Property-Based Automatic Program Repair","Gissurarson, Matthías Páll (Chalmers University of Technology); Applis, L.H. (TU Delft Software Engineering); Panichella, A. (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology); Sands, David (Chalmers University of Technology)","","2022","Automatic program repair (APR) regularly faces the challenge of overfitting patches — patches that pass the test suite, but do not actually address the problems when evaluated manually. Currently, overfit detection requires manual inspection or an oracle making quality control of APR an expensive task. With this work, we want to introduce properties in addition to unit tests for APR to address the problem of overfitting. To that end, we design and im- plement PropR, a program repair tool for Haskell that leverages both property-based testing (via QuickCheck) and the rich type system and synthesis offered by the Haskell compiler. We compare the repair-ratio, time-to-first-patch and overfitting-ratio when using unit tests, property-based tests, and their combination. Our results show that properties lead to quicker results and have a lower overfit ratio than unit tests. The created overfit patches provide valuable insight into the underlying problems of the program to repair (e.g., in terms of fault localization or test quality). We consider this step towards fitter, or at least insightful, patches a critical contribution to bring APR into developer workflows.","Automatic program repair; Search-based Software Engineering; Program synthesis; Property-based testing; Haskell","en","conference paper","IEEE / ACM","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:510c2536-d640-4c53-bbc2-d4b1110a7729","http://resolver.tudelft.nl/uuid:510c2536-d640-4c53-bbc2-d4b1110a7729","The role of cell-matrix interactions in connective tissue mechanics","Muntz, I.A.A. (TU Delft BN/Gijsje Koenderink Lab; Kavli institute of nanoscience Delft); Fenu, M. (Erasmus MC); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Koenderink, G.H. (TU Delft BN/Gijsje Koenderink Lab; Kavli institute of nanoscience Delft)","","2022","Living tissue is able to withstand large stresses in everyday life, yet it also actively adapts to dynamic loads. This remarkable mechanical behaviour emerges from the interplay between living cells and their non-living extracellular environment. Here we review recent insights into the biophysical mechanisms involved in the reciprocal interplay between cells and the extracellular matrix and how this interplay determines tissue mechanics, with a focus on connective tissues. We first describe the roles of the main macromolecular components of the extracellular matrix in regards to tissue mechanics. We then proceed to highlight the main routes via which cells sense and respond to their biochemical and mechanical extracellular environment. Next we introduce the three main routes via which cells can modify their extracellular environment: exertion of contractile forces, secretion and deposition of matrix components, and matrix degradation. Finally we discuss how recent insights in the mechanobiology of cell-matrix interactions are furthering our understanding of the pathophysiology of connective tissue diseases and cancer, and facilitating the design of novel strategies for tissue engineering.","connective tissue; extracellular matrix; mechanobiology; mechanosensing; mechanotransduction; polymer physics; tissue engineering","en","review","","","","","","","","","","","BN/Gijsje Koenderink Lab","","",""
"uuid:b980f739-a969-4f5a-983c-87d35ff661d6","http://resolver.tudelft.nl/uuid:b980f739-a969-4f5a-983c-87d35ff661d6","Alarm-based predictive maintenance scheduling for aircraft engines with imperfect Remaining Useful Life prognostics","de Pater, I.I. (TU Delft Air Transport & Operations); Reijns, Arthur (Student TU Delft); Mitici, M.A. (TU Delft Air Transport & Operations)","","2022","The increasing availability of condition monitoring data for aircraft components has incentivized the development of Remaining Useful Life (RUL) prognostics in the past years. However, only few studies consider the integration of such prognostics into maintenance planning. In this paper we propose a dynamic, predictive maintenance scheduling framework for a fleet of aircraft taking into account imperfect RUL prognostics. These prognostics are periodically updated. Based on the evolution of the prognostics over time, alarms are triggered. The scheduling of maintenance tasks is initiated only after these alarms are triggered. Alarms ensure that maintenance tasks are not rescheduled multiple times. A maintenance task is scheduled using a safety factor, to account for potential errors in the RUL prognostics and thus avoid component failures. We illustrate our approach for a fleet of 20 aircraft, each equipped with 2 turbofan engines. A Convolution Neural Network is proposed to obtain RUL prognostics. An integer linear program is used to schedule aircraft for maintenance. With our alarm-based maintenance framework, the costs with engine failures account for only 7.4% of the total maintenance costs. In general, we provide a roadmap to integrate imperfect RUL prognostics into the maintenance planning of a fleet of vehicles.","Aircraft maintenance; Fleet of aircraft; Predictive maintenance planning; RUL prognostics; Turbofan engines","en","journal article","","","","","","","","","","","Air Transport & Operations","","",""
"uuid:01dfc02e-e368-447c-b4a9-3ba028f08347","http://resolver.tudelft.nl/uuid:01dfc02e-e368-447c-b4a9-3ba028f08347","Never Ask for a Lighter Rain but a Stronger Umbrella","Pande, S. (TU Delft Water Resources); Haeffner, Melissa (Portland State University); Blöschl, Günter (Technische Universität Wien); Alam, M.F. (TU Delft Water Resources; International Water Management Institute); Castro, Cyndi (University of Houston); Di Baldassarre, Giuliano (Uppsala University); Frick-Trzebitzky, Fanny (ISOE—Institute for Social-Ecological Research); Hogeboom, Rick (University of Twente; Water Footprint Network); Kreibich, Heidi (German Research Centre for Geosciences); Mukherjee, Jenia (Indian Institute of Technology (IIT))","","2022","In a recent editorial in the journal Nature Sustainability, the editors raised the concern that journal submissions on water studies appear too similar. The gist of the editorial: “too many publications and not enough ideas.” In this response, we contest this notion, and point to the numerous new ideas that result from taking a broader view of the water science field. Drawing inspiration from a recently hosted conference geared at transcending traditional disciplinary silos and forging new paradigms for water research, we are, in fact, enthusiastic and optimistic about the ways scientists are investigating political, economic, historical, and cultural intersections toward more just and sustainable human-water relations and ways of knowing.","conceptual and methodological pluralism; first sociohydrology conference; inclusive dialogues; societal feedbacks within engineering designs; water crises","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:9147ad32-79b6-4a09-a6d8-e65136198c2f","http://resolver.tudelft.nl/uuid:9147ad32-79b6-4a09-a6d8-e65136198c2f","Proving compliance of satellite InSAR technology with geotechnical design codes","Reinders, K.J. (TU Delft Hydraulic Structures and Flood Risk); Giardina, Giorgia (TU Delft Geo-engineering); Zurfluh, Florian (Geotechnisches Institut AG); Ryser, Jurg (B+S AG); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning)","","2022","In the planning stage of new infrastructure or when designing renovation of existing infrastructure, information about existing slope movements or settlements is essential to make informed design decisions. Interferometric
Synthetic Aperture Radar (InSAR) techniques can be of value to identify these risks in an early stage of a project. InSAR can offer insight into the surface movements of an area from historic archives using satellite-based SAR
data. Furthermore, InSAR observations can help identify zones with displacements larger than the average of an area, and be used to plan future soil investigation more effectively. Thanks to their high temporal and spatial resolution, InSAR observations can also complement in situ conventional monitoring during the construction and operational stage. Despite these possibilities, the use of InSAR is not yet standard practice in geotechnical projects
and no formal guidelines are currently available to inform engineers, planners and infrastructure stakeholder on the use of InSAR-based monitoring within geotechnical design codes. Here we provide an operational framework for the practical integration of InSAR monitoring into current geotechnical design codes, such as Eurocode-7, for all project stages. The proposed framework is then demonstrated for the planning stage of a highway renovation project, focusing on an area potentially subjected to landslides where no conventional monitoring
data was available at this stage. We concluded that the proposed framework is a practical and operational
tool that can be used by planners and engineers in the whole lifecycle of an infrastructure project.","InSAR; Geotechnical engineering practice; Monitoring; Eurocode 7","en","journal article","","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:a70f0474-9d14-40a8-9787-f622e3565559","http://resolver.tudelft.nl/uuid:a70f0474-9d14-40a8-9787-f622e3565559","Façades-as-a-Service: The Role of Technology in the Circular Servitisation of the Building Envelope","Azcarate Aguerre, J.F. (TU Delft Building Product Innovation); Klein, T. (TU Delft Building Product Innovation); Konstantinou, T. (TU Delft Building Product Innovation); Veerman, Martijn (Alkondor Hengelo B.V.)","","2022","The servitisation of the built environment, through the implementation of product–service systems, is considered a promising business strategy to achieve a circular economy transition. This servitisation faces a number of practical challenges, among them the technological readiness and effective integration and application of existing and emerging products, manufacturing processes, and digital monitoring and management tools. The research builds on targeted literature review, and on a research-through-design approach based on full-scale pilot projects developed in an ongoing feedback loop between researchers, planners, and industry partners representing both the demand and supply sides of the façade industry in the Netherlands. The paper analyses the technical implementation challenges currently preventing the façade industry from adopting performance-based contracts. It then proposes the roles that existing and emerging digital design and engineering technologies, manufacturing processes, and asset management systems can play in the development, implementation, and fulfilment of such contracts. The paper proposes a multi-stakeholder, systemic model for the development and application of façade technologies capable of overcoming many of the technical implementation barriers to the delivery of performance-based contracts for integrated facades. From this it concludes that an effective development of building technologies should strategically align with the solving of economic and contractual challenges such as circularity-readiness, profitability, risk distribution, legal demarcation, performance monitoring, and residual value stewardship. The resulting framework provides a strategic and conceptual basis for the development of circularity-enabling façade technologies, accounting for the diverse and sometimes conflicting interests of the multitude of stakeholders involved throughout a project’s lifecycle. The framework aims to support planners, manufacturers, and builders accelerate the circular deep energy renovation of the built environment while also exploring new business opportunities.","façade engineering; circular economy; product–service systems; energy renovation; built environment; performance contracts; facades-as-a-service; service integration","en","journal article","","","","","","","","","","","Building Product Innovation","","",""
"uuid:3fe18d2d-1718-4f94-9202-5cf81f71224e","http://resolver.tudelft.nl/uuid:3fe18d2d-1718-4f94-9202-5cf81f71224e","Fatigue life and cracking characterization of engineered cementitious composites (ECC) under flexural cyclic load","Sun, Renjuan (Shandong University); Han, Lebing (Shandong Hi-Speed Engineering Test CO); Zhang, Hongzhi (Shandong University); Ge, Zhi (Shandong University); Guan, Yanhua (Shandong University); Ling, Yifeng (Shandong University); Schlangen, E. (TU Delft Materials and Environment); Šavija, B. (TU Delft Materials and Environment)","","2022","This paper presents a study on cracking characterization of engineered cementitious composites (ECC) under flexural cyclic load using digital image correlation (DIC) technique. Five stress levels, namely 0.65, 0.75, 0.8, 0.85 and 0.9 of the flexural strength, were applied. Strain map at the side surface was obtained by DIC and used to drive evolution of the midspan deflection, damage pattern, maximum crack width, number of cracks, and crack width distribution with respect to the normalized number of cycles. The stress level was found to have a significant influence on the cracking behavior of ECC under flexural cyclic load. Regardless of the applied stress level, most of the crack widths are in the range between 20 and 80 μm. In the end, a two-dimension Gauss function was used to correlate the crack width distribution with normalized number of cycle and shows satisfactory results.","Fatigue life; Engineered cementitious composites; Digital image correlation; Cracking behavior","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-10-19","","","Materials and Environment","","",""
"uuid:8e0fef1d-0e31-4c53-878a-00753cd9fa18","http://resolver.tudelft.nl/uuid:8e0fef1d-0e31-4c53-878a-00753cd9fa18","The epsilon-knowledge: an emerging complement of Machlup's types of disciplinary knowledge","Horvath, I. (TU Delft Cyber-Physical Systems)","","2022","Machlup used the words alpha, beta, and gamma to identify humanities, science, and social science as three distinct fields of academic learning and knowing, in addition to general knowledge. Gilles and Paquet identified a fourth type of disciplinary knowledge and labeled it as delta. This includes the knowledge of creative disciplines such as design, law, and economy. Since the time of these road-paving works, a lot has changed. In the last two decades, various concepts and manifestations of intellectualized engineered systems have appeared. A paradigmatic feature of these systems, exemplified by smart cyber-physical systems, is that they collect, infer, or extract massive amount of synthetic system knowledge (M-SSK) based on some pre-programmed human knowledge. The amount of this type of knowledge grows continuously. It can be aggregated on system level and on system of systems level. This paper argues that this aggregated M-SSK is not covered by the abovementioned four genres of knowledge. In fact, it represents a new genre. The conducted literature study underpins this claim. Therefore, the paper suggests dealing with it as a new genre, called epsilon-knowledge. Artificial intelligence, system engineering, cyber-physical systems, and knowledge engineering are the disciplines dealing with epsilon-knowledge. The paper refers to sympérasmology as the proper conceptual framework of studying this genre of knowledge.","epsilon-knowledge; genres of knowledge; intellectualized engineered systems; Key words Beyond ABGD-knowledge; sympérasmology; synthetic systems knowledge","en","journal article","","","","","","","","","","","Cyber-Physical Systems","","",""
"uuid:937ac5b7-e1c3-485e-a7d2-cca036c3e95d","http://resolver.tudelft.nl/uuid:937ac5b7-e1c3-485e-a7d2-cca036c3e95d","Gender, prior knowledge, and the impact of a flipped linear algebra course for engineers over multiple years","Hardebolle, Cécile (EPFL Switzerland); Verma, H. (TU Delft Human-Centred Artificial Intelligence); Tormey, Roland (EPFL Switzerland); Deparis, Simone (EPFL Switzerland)","","2022","Background: Research shows that active pedagogies could play an important role in achieving more equitable outcomes for diverse groups of students in Science, Technology, Engineering, and Mathematics (STEM). Although flipped classes are a popular active methodology, there is a lack of high-quality studies assessing their impact in ecologically valid settings and exploring how outcomes are related to gender and to prior education. Purpose: This paper presents two modified replications of an experimental study investigating the impact of the flipped class approach on students' achievement in a large, first-year class in an engineering bachelor's degree. Methodology: We added a new strand, progressively flipped over 3 years, to eight parallel strands of a high-stakes mandatory linear algebra course for engineers. The study followed a replicated-between-subjects design, with students in the flipped strand learning the same material as those in the other strands and taking the same final exam. Results: Our results demonstrate that the flipped format did not have any significant impact on students' achievement compared to traditional lecturing. However, both replications in the flipped condition show a reduced attainment gap for women and students with less prior knowledge in mathematics. Conclusion: While the flipped class seems to have weaker effects on learning than other active methodologies, the evidence in this study indicates that it may have an impact on reducing the attainment gap between different groups of students. It may therefore be particularly interesting to consider in efforts to achieve more equitable outcomes for women and where students have heterogeneous educational backgrounds.","Active learning; engineering education; experimental research; flipped class; gender; linearalgebra","en","journal article","","","","","","","","","","","Human-Centred Artificial Intelligence","","",""
"uuid:50e93daa-49e9-434f-b845-6e754d91dc12","http://resolver.tudelft.nl/uuid:50e93daa-49e9-434f-b845-6e754d91dc12","Best Practices for Longitudinal Training Walls to mitigate channel bed erosion","Czapiga, Matthew (University of South Carolina); Blom, A. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Viparelli, Enrica (University of South Carolina)","Blom, Astrid (editor); Stancanelli, Laura M. (editor); Dercksen, Jelle A. (editor); Ylla Arbós, Clàudia (editor); Chowdhury, M. Kifayath (editor); Ahrendt, Shelby M. (editor); Piccoli, Carolina (editor); Schielen, Ralph M.J. (editor); Sloff, Kees (editor); Slinger, Jill H. (editor)","2022","","Morphodynamics; Longitudinal Training Walls; River Engineering","en","conference paper","","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:8e323b30-018a-4e7c-843d-04ac5814f924","http://resolver.tudelft.nl/uuid:8e323b30-018a-4e7c-843d-04ac5814f924","Engineering Systems Design: A Look to the Future","Maier, Anka (Technical University of Denmark; University of Strathclyde); Oehmen, Josef (Technical University of Denmark); Vermaas, P.E. (TU Delft Ethics & Philosophy of Technology)","Maier, Anja (editor); Oehmen, Josef (editor); Vermaas, Pieter E. (editor)","2022","Engineering Systems Design is an emerging perspective with a growing community. The preceding chapters in the Handbook of Engineering Systems Design presented the engineering systems perspective, models for describing and methods for designing interventions in engineering systems, as well as reflections on the use of those methods and upcoming practice, educational and policy challenges. In this chapter, we are taking a look at the future of Engineering Systems Design. We start by highlighting productivity, sustainability and resilience as three societal objectives, and proceed to discuss critical paradoxes we must address through engineering systems interventions: providing a high standard of living for everyone, without paying the environmental price; a fast minimisation and mitigation of climate change without taking risks; and the challenge of global transformations respecting local needs. We continue to discuss what we consider three critical engineering systems design capabilities we must develop to resolve these paradoxes: the ability to manage systems requirements at societal scale; the development of scale-covariant engineering systems; and mastering connectability. We conclude the chapter with a call to action for researchers, practitioners and policy makers to advance theory, design methods and tools, and stakeholder outreach development to strengthen our engineering systems design capabilities.","Capabilities; Design; Engineering Systems Design; Future Developments; Paradoxes; Resilience; Sustainability","en","book chapter","Springer Nature","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Ethics & Philosophy of Technology","","",""
"uuid:9c097e55-4084-48a3-8703-39f59b6ee1aa","http://resolver.tudelft.nl/uuid:9c097e55-4084-48a3-8703-39f59b6ee1aa","3D Printing for Repair Guide","Bolanos Arriola, J. (TU Delft Design for Sustainability); van Oudheusden, A.A. (TU Delft Circular Product Design); Flipsen, Bas (TU Delft Circular Product Design); Faludi, Jeremy (TU Delft Circular Product Design)","","2022","This guide takes the reader through the 3D Printing for Repair (3DP4R) process. It consists of guidelines and tools to create a 3D printable version of spare parts needed for a product repair. 3D printing a spare part is more than just printing the original part. Instead, it is an iterative process in which the part is analysed, redesigned, manufactured, and tested, in order to come to a final part. This guide will describe these four phases in detail. The guide is meant for anybody who is interested in trying to manufacture spare parts with 3D printing technologies, remakers, tinkerers, volunteer repairers, professional repairers, and everyone who is interested in repair initiatives.","FDM; 3D printing; repair; spare part; design; engineering; additive manufacturing; sustainability; circular","en","book","TU Delft OPEN Publishing","978-94-6366-540-7","","","","","","","","","Design for Sustainability","","",""
"uuid:f8c6f4bf-db0f-483c-aedd-8c9be76b7c33","http://resolver.tudelft.nl/uuid:f8c6f4bf-db0f-483c-aedd-8c9be76b7c33","Assessing Peroxygenase-Mediated Oxidations in the Presence of High Concentrations of Water-Miscible Co-Solvents","Hilberath, T. (TU Delft BT/Biocatalysis); van Troost, A.G.L. (Student TU Delft); Alcalde, Miguel (Institute of Catalysis, CSIC, Madrid); Hollmann, F. (TU Delft BT/Biocatalysis)","","2022","The use of water-miscible organic co-solvents in biocatalysis is a simple procedure for obtaining higher enzymatic activities toward hydrophobic substrates. However, effects on activity and stability have to be carefully evaluated, also with regard to the type and concentration of the respective co-solvent. In this contribution, we investigated and evaluated the effect of some common water-miscible co-solvents on the biocatalytic performance of the recombinant unspecific peroxygenase rAaeUPO from Agrocybe aegerita. rAaeUPO showed promising activities in the presence of high concentrations of the best co-solvent acetonitrile, which enabled to use higher substrate concentrations (≥100 mM). Employing high acetonitrile concentrations for UPO-mediated oxidation of ethylbenzene to (R)-1-phenylethanol was demonstrated under preparative scale conditions and led to product accumulation rates of 31 mM h−1.","peroxygenase; oxyfunctionalization; co-solvent; ydroxylation; poxidation; medium engineering","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:fc4e2697-811d-495a-887c-172745fe33d2","http://resolver.tudelft.nl/uuid:fc4e2697-811d-495a-887c-172745fe33d2","Guiding Automated Test Case Generation for Transaction-Reverting Statements in Smart Contracts","Olsthoorn, Mitchell (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology); Panichella, A. (TU Delft Software Engineering)","Ceballos, Cristina (editor)","2022","Transaction-reverting statements are key constructs within Solidity that are extensively used for authority and validity checks. Current state-of-the-art search-based testing and fuzzing approaches do not explicitly handle these statements and therefore can not effectively detect security vulnerabilities. In this paper, we argue that it is critical to directly handle and test these statements to assess that they correctly protect the contracts against invalid requests. To this aim, we propose a new approach that improves the search guidance for these transaction-reverting statements based on interprocedural control dependency analysis, in addition to the traditional coverage criteria. We assess the benefits of our approach by performing an empirical study on 100 smart contracts w.r.t. transaction-reverting statement coverage and vulnerability detection capability. Our results show that the proposed approach can improve the performance of DynaMOSA, the state-of-the-art algorithm for test case generation. On average, we improve transaction-reverting statement coverage by 14 % (up to 35 %), line coverage by 8 % (up to 32 %), and vulnerability-detection capability by 17 % (up to 50 %).","test case generation; smart contracts; search-based software engineering; fuzzing","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","Software Technology","Software Engineering","","",""
"uuid:203a5f82-1095-4ca4-bc6c-c3f963828f5b","http://resolver.tudelft.nl/uuid:203a5f82-1095-4ca4-bc6c-c3f963828f5b","Real-time UAV routing strategy for monitoring and inspection for post-disaster restoration of distribution networks","Fu, J. (TU Delft Team Bart De Schutter); Nunez, Alfredo (TU Delft Railway Engineering); De Schutter, B.H.K. (TU Delft Team Bart De Schutter)","","2022","Natural disasters pose a tremendous risk to the reliability of distribution networks. In this paper, a novel real-time UAV routing strategy for coordination between monitoring and inspection for post-disaster restoration in distribution networks is proposed. With our proposed real-time UAV routing strategy, damages can be inspected by UAVs for post-disaster restoration. Besides, transmission lines can be monitored to find potential dangers, and road infrastructure can also be monitored to provide real-time information about traffic conditions so that repair crews can select the best ways to reach damages. In addition, due to unpredictable events during restoration, the UAV routing strategy and schedule need to be updated in real time. Then, to tackle the multi-time-scale characteristic of the proposed UAV routing strategy, a two-layer computation architecture is proposed. A case study based on the distribution network in Zaltbommel, the Netherlands, illustrates the effectiveness of the proposed method compared to other approaches.","Distribution network post-disaster restoration; Distribution networks; Inspection; Maintenance engineering; Monitoring; monitoring and inspection coordination; real-time routing for unpredictable events; Real-time systems; Roads; Routing; unmanned aerial vehicles routing strategy","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","","","","Team Bart De Schutter","","",""
"uuid:c9777eb5-fa0a-4c9b-a02d-ea1de82fe1e1","http://resolver.tudelft.nl/uuid:c9777eb5-fa0a-4c9b-a02d-ea1de82fe1e1","Factors Affecting On-Time Delivery in Large-Scale Agile Software Development","Kula, E. (TU Delft Software Engineering; ING); Greuter, Eric (ING); van Deursen, A. (TU Delft Software Technology); Gousios, G. (TU Delft Software Engineering)","","2022","Late delivery of software projects and cost overruns have been common problems in the software industry for decades. Both problems are manifestations of deficiencies in effort estimation during project planning. With software projects being complex socio-technical systems, a large pool of factors can affect effort estimation and on-time delivery. To identify the most relevant factors and their interactions affecting schedule deviations in large-scale agile software development, we conducted a mixed-methods case study at ING: two rounds of surveys revealed a multitude of organizational, people, process, project and technical factors which were then quantified and statistically modeled using software repository data from 185 teams. We find that factors such as requirements refinement, task dependencies, organizational alignment and organizational politics are perceived to have the greatest impact on on-time delivery, whereas proxy measures such as project size, number of dependencies, historical delivery performance and team familiarity can help explain a large degree of schedule deviations. We also discover hierarchical interactions among factors: organizational factors are perceived to interact with people factors, which in turn impact technical factors. We compose our findings in the form of a conceptual framework representing influential factors and their relationships to on-time delivery. Our results can help practitioners identify and manage delay risks in agile settings, can inform the design of automated tools to predict schedule overruns and can contribute towards the development of a relational theory of software project management.","Software engineering management; effort estimation; empirical studies; software companies","en","journal article","","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:19b6cf70-fc08-4fdd-b324-25f1815e3274","http://resolver.tudelft.nl/uuid:19b6cf70-fc08-4fdd-b324-25f1815e3274","Online Optimization of Gear Shift and Velocity for Eco-Driving using Adaptive Dynamic Programming","Li, Guoqiang (Beijing Institute of Technology); Gorges, Daniel (Technische Universität Kaiserslautern); Wang, M. (TU Delft Transport and Planning)","","2022","In this paper a learning-based optimization method for online gear shift and velocity control is presented to reduce the fuel consumption and improve the driving comfort in a car-following process. The continuous traction force and the discrete gear shift are optimized jointly to improve both the powertrain operation and the longitudinal motion. The problem is formulated as a nonlinear mixed-integer optimization problem and solved based on adaptive dynamic programming. A major difference compared to existing approaches is that the developed control method is model-free, i.e. it does not rely on vehicle models. It can address system nonlinearities and adapt to changes in engine characteristics (e.g. consumption map) during vehicle driving. The computation is efficient and enables possible real-time implementation. The proposed control method is studied for an urban driving cycle to evaluate the control performance with respect to the fuel economy and the driving comfort. Simulations indicate that the host vehicle can reduce the fuel consumption by 5.03% and 1.12% for two consumption maps in comparison to the preceding while keeping a desired inter-vehicle distance. The results further show a decrease of 1.59% and 2.32% in fuel consumption compared to a linear quadratic controller with the same gear shift schedule.","adaptive cruise control; adaptive dynamic programming; Biological system modeling; Eco-driving; Engines; Force; Fuel economy; gear shift schedule; Gears; Optimization; reinforcement learning; Vehicle dynamics; velocity optimization","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Transport and Planning","","",""
"uuid:5687c86b-9c42-4036-90e0-2ee777ff9caf","http://resolver.tudelft.nl/uuid:5687c86b-9c42-4036-90e0-2ee777ff9caf","The epsilon-knowledge:: An emerging complement of Machlup’s types of disciplinary knowledge","Horvath, I. (TU Delft Cyber-Physical Systems)","","2022","Machlup, F. used the words alpha, beta, and gamma to identify humanities, science, and social science as three distinct fields of academic learning and knowing, in addition to general knowledge. Gilles, W. and Paquet, G. identified a fourth type of disciplinary knowledge and labelled it as delta. This includes the knowledge of creative disciplines such as design, law, and economy. Since the time of these road-paving works, a lot has changed. In the last two decades, various concepts and manifestations of intellectualized engineered systems have appeared. A paradigmatic feature ofthese systems, exemplified by smart cyber-physical systems, is that they collect, infer, or extract massive amount of synthetic system knowledge (M-SSK) based on some pre-programmed human
knowledge. The amount of this type of knowledge grows continuously. It can be aggregated on system level as well as on system of systems level. This paper argues that this aggregated M-SSK is not covered by the abovementioned four genres of knowledge. In fact, it represents a new genre. The conducted literature study underpins this claim. Therefore, the paper suggests dealing with it as
a new genre, called epsilon-knowledge. Artificial intelligence, system engineering, cyber-physical systems, and knowledge engineering are the disciplines dealing with epsilon-knowledge. The paper refers to sympérasmology as the proper conceptual framework of studying this genre of knowledge.","Genres of knowledge; beyond ABGD-knowledge; intellectualized engineered systems; ynthetic systems knowledge; epsilon-knowledge; sympérasmology","en","journal article","","","","","","","","","","","Cyber-Physical Systems","","",""
"uuid:54d7ccfa-6f29-4213-a80a-b5dda73f1e04","http://resolver.tudelft.nl/uuid:54d7ccfa-6f29-4213-a80a-b5dda73f1e04","Optimization of complex-geometry high-rise buildings based on wind load analysis","Estrado, Erron (Student TU Delft); Turrin, M. (TU Delft Design Informatics); Eigenraam, P. (TU Delft Structural Design & Mechanics)","","2022","As technology advances, architects often employ innovative, non-standard shapes in their designs for the fast-growing number of high-rise buildings. Conversely, climate change is bringing about an increasing number of dangerous wind events causing damage to buildings and their surroundings. These factors further complicate the already difficult field of structural wind analysis. Current methods for calculating structural wind response, such as the Eurocode, do not provide methods for unconventional building shapes or, in the case of physical wind tunnel test and in-depth computational fluid dynamics (CFD) simulation, they are prohibitively expensive and time-consuming. Thus, wind load analysis is often relegated to late in the design process. This paper presents the development of a computational method to analyze the effect of wind on the structural behavior of a 3D building model and optimize the external geometry to reduce those effects at an early design phase. It combines CFD, finite-element analysis (FEA), and an optimization algorithm in the popular parametric design tool, Grasshopper. This allows it to be used in an early design stage for performance-based design exploration in complement to the more traditional late-stage methods outlined above. After developing the method and testing the timeliness and precision of the CFD, and FEA portions on case study buildings, the tool was able to output an optimal geometry as well as a database of improved geometric options with their corresponding performance for the wind loading.","Computational fluid dynamics; computational wind engineering; finite-element analysis; generative design; optimization","en","journal article","","","","","","","","","","","Design Informatics","","",""
"uuid:768b22b4-e39e-4983-b2c8-3e1212ce0579","http://resolver.tudelft.nl/uuid:768b22b4-e39e-4983-b2c8-3e1212ce0579","Flight dynamics and control assessment for differential thrust aircraft in engine inoperative conditions including aero-propulsive effects","Hoogreef, M.F.M. (TU Delft Flight Performance and Propulsion); Soikkeli, Johannes S.E. (Pipistrel Vertical Solutions d.o.o.)","","2022","Differential thrust can be used for directional control on distributed electric propulsion aircraft. This paper presents an assessment of flight dynamics and control under engine inoperative conditions at minimum control speed for a typical distributed propulsion aircraft employing differential thrust. A methodology consisting of an aerodynamic data acquisition module and a non-linear six-degrees-of-freedom flight dynamics model is proposed. Directional control is achieved using a controller to generate a yaw command, which is distributed to the propulsors through a thrust mapping approach. A modified version of the NASA X-57 aircraft is selected for case studies, where the engine inoperative condition is considered to impact the three leftmost propulsors during climb at minimum control speed. The objective also includes the assessment of the impact of the aero-propulsive coupling for such an aircraft during a failure case. Results show that during the recovery manoeuvre, the aircraft experiences a 78% reduction in total thrust and 30% reduction in total lift caused by the aggressive yaw control effort required to control the heading of the aircraft. Consequently, the powered-stall speed is increased, and the aircraft temporarily loses altitude during the recovery manoeuvre. Differential thrust provides sufficient yaw authority during the engine inoperative condition, and is, therefore, seen to potentially replace the functionality of the rudder for the climb condition that was studied. Additionally, reduction of the vertical tail area was explored and seen to be possible if the response time of the system is low enough. For the studied configuration, this required a response within 400 ms for reduced vertical tail areas.","Aero-propulsive effects; Differential thrust; Directional control; Distributed electric propulsion; Engine inoperative conditions","en","journal article","","","","","","","","","","","Flight Performance and Propulsion","","",""
"uuid:54e77120-3ffd-4250-9227-2795d2b94d86","http://resolver.tudelft.nl/uuid:54e77120-3ffd-4250-9227-2795d2b94d86","Technology as Driver for Morally Motivated Conceptual Engineering","Veluwenkamp, H.M. (TU Delft Ethics & Philosophy of Technology); Capasso, M. (Sant'Anna School of Advanced Studies); Maas, J.J.C. (TU Delft Ethics & Philosophy of Technology); Marin, L. (TU Delft Ethics & Philosophy of Technology)","","2022","New technologies are the source of uncertainties about the applicability of moral and morally connotated concepts. These uncertainties sometimes call for conceptual engineering, but it is not often recognized when this is the case. We take this to be a missed opportunity, as a recognition that different researchers are working on the same kind of project can help solve methodological questions that one is likely to encounter. In this paper, we present three case studies where philosophers of technology implicitly engage in conceptual engineering (without naming it as such). We subsequently reflect on the case studies to find out how these illustrate conceptual engineering as an appropriate method to deal with pressing concerns in the philosophy of technology. We have two main goals. We first want to contribute to the literature on conceptual engineering by presenting concrete examples of conceptual engineering in the philosophy of technology. This is especially relevant, because the technologies that are designed based on the conceptual work done by philosophers of technology potentially have crucial moral and social implications. Secondly, we want to make explicit what choices are made when doing this conceptual work. Making explicit that some of the implicit assumptions are, in fact, debated in the literature allows for reflection on these questions. Ultimately, our hope is that conscious reflection leads to an improvement of the conceptual work done.
This article proposes an efficient correction model that enables the extension of the blade element momentum method (BEM) for swept blades. Standard BEM algorithms, assuming a straight blade in the rotor plane, cannot account for the changes in the induction system introduced by blade sweep. The proposed extension corrects the axial induction regarding two aspects: the azimuthal displacement of the trailed vorticity system and the induction of the curved bound vortex on itself. The extended algorithm requires little additional processing work and maintains BEM's streamtube independent approach. The proposed correction model is applied to simulations of swept blade geometries based on the IEA 15 MW reference wind turbine. Results show good agreement with lifting line simulations that inherently can account for the swept blade geometry.
Blade sweep couples bending and torsion deformations by curving the blade axis in the inplane direction. As such, it can be used to passively alleviate loads and, thus, aeroelastically tailor wind turbine blades. The implementation of aeroelastic tailoring techniques, and the aeroelastic analysis in general, becomes increasingly significant with the size of wind turbine rotors continually rising. Due to its low computing complexity, BEM remains a crucial tool in the aerodynamic and aeroelastic analysis of wind turbine rotors. Thus, the proposed correction model contributes to a fast and accurate evaluation of swept blade designs.
techniques, make it currently impossible to perform an adequate environmental risk assessment. As a result, there is a risk that such techniques don’t get beyond experiments demonstrating the proof of principle, stifling their further
development and implementation. To break free from this deadlock, wemust be able to learn what such uncertainties and uncertain risks entail, and how they should be assessed to ensure safe further development. To shape a responsible learning environment to explore uncertainties and uncertain risks, we have organized five stakeholder workshops. By means of a case about the genetic engineering of plants’ rhizosphere–an application abundant with uncertain risks–we identified tensions between different stakeholder groups and their different estimates of uncertainties and uncertain risks. Based upon derived insights, we developed a tool–a script for researchers to organize a
stakeholder workshop–that enables a constructive discussion about emerging risks with a broad range of stakeholders. Thereby, the script provides a step-by-step approach to identify uncertainties, develop anticipatory strategies and adaptations in (experimental) research designs to lower or mitigate the earlier
identified uncertainties, and helps to identify knowledge gaps for which (additional) risk research should be set up.","uncertain risks; safety; mutual learning; safe-by-design; responsibility; plant engineering","en","journal article","","","","","","","","","","","BT/Biotechnology and Society","","",""
"uuid:7cca8ecd-778b-44f2-a30f-d169eeb44cf7","http://resolver.tudelft.nl/uuid:7cca8ecd-778b-44f2-a30f-d169eeb44cf7","Engineering Systems in Flux: Designing and Evaluating Interventions in Dynamic Systems","Bots, P.W.G. (TU Delft Policy Analysis)","","2022","This chapter discusses the threefold challenge of designing effective interventions in engineering systems that are constantly changing: (1) a designed socio-technical artefact should improve system performance not only under present conditions, but it must also be functional when conditions change, be it autonomously or due to interventions performed by others, and (2) the actual intervention of implementing the artefact should be planned such that it does not disrupt functional processes elsewhere, while (3) the implementation process should be impervious to such contingent processes. To meet this challenge, engineers can deploy different strategies: design strategies that will enhance the robustness of an artefact, its flexibility, or its capacity for (planned) evolution; strategies that will stabilise the context of the artefact; and implementation strategies that will contain and shield the intervention. This chapter reviews these strategies, discusses how they relate to systems engineering methodologies, and then highlights exploratory modeling and participatory modeling as methods for ex ante evaluation of interventions in dynamic engineering systems.","Adaptive design; Engineering systems; Flexible design; Implementation plan; Institutions; Planned intervention; Robust design","en","book chapter","Springer Nature","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Policy Analysis","","",""
"uuid:2a24f761-3e84-496c-a94c-f6dc5d8c1727","http://resolver.tudelft.nl/uuid:2a24f761-3e84-496c-a94c-f6dc5d8c1727","Deep reinforcement learning for predictive aircraft maintenance using probabilistic Remaining-Useful-Life prognostics","Lee, J. (TU Delft Air Transport & Operations); Mitici, M.A. (Universiteit Utrecht)","","2022","The increasing availability of sensor monitoring data has stimulated the development of Remaining-Useful-Life (RUL) prognostics and maintenance planning models. However, existing studies focus either on RUL prognostics only, or propose maintenance planning based on simple assumptions about degradation trends. We propose a framework to integrate data-driven probabilistic RUL prognostics into predictive maintenance planning. We estimate the distribution of RUL using Convolutional Neural Networks with Monte Carlo dropout. These prognostics are updated over time, as more measurements become available. We further pose the maintenance planning problem as a Deep Reinforcement Learning (DRL) problem where maintenance actions are triggered based on the estimates of the RUL distribution. We illustrate our framework for the maintenance of aircraft turbofan engines. Using our DRL approach, the total maintenance cost is reduced by 29.3% compared to the case when engines are replaced at the mean-estimated-RUL. In addition, 95.6% of unscheduled maintenance is prevented, and the wasted life of the engines is limited to only 12.81 cycles. Overall, we propose a roadmap for predictive maintenance from sensor measurements to data-driven probabilistic RUL prognostics, to maintenance planning.","predictive maintenance; remaining useful life; probabilistic RUL prognostics; deep reinforcement learning; turbofan engines","en","journal article","","","","","","","","","","","Air Transport & Operations","","",""
"uuid:123137a6-11ca-4a84-ba36-4d60e8aa307d","http://resolver.tudelft.nl/uuid:123137a6-11ca-4a84-ba36-4d60e8aa307d","Challenges in Applying Continuous Experimentation: A Practitioners' Perspective","Anderson, K.S. (TU Delft Software Engineering; Vista); Visser, Denise (Bol.com); Mannen, Jan-Willem (ING); Jiang, Yuxiang (Student TU Delft); van Deursen, A. (TU Delft Software Technology)","","2022","Background: Applying Continuous Experimentation on a large scale is not easily achieved. Although the evolution within large tech organisations is well understood, we still lack a good understanding of how to transition a company towards applying more experiments. Objective: This study investigates how practitioners define, value and apply experimentation, the blockers they experience and what to do to solve these. Method: We interviewed and surveyed over one hundred practitioners with regards to experimentation perspectives, from a large financial services and e-commerce organization, based in the Netherlands. Results: Many practitioners have different perspectives on experimentation. The value is well understood. We have learned that the practitioners are blocked by a lack of priority, experience and well functioning tooling. Challenges also arise around dependencies between teams and evaluating experiments with the correct metrics. Conclusions: Organisation leaders need to start asking for experiment results and investing in infrastructure and processes to actually enable teams to execute experiments and show the value of their work in terms of value for customers and business.","Continuous experimentation; Online controlled experiments; A/B testing; Empirical software engineering; ING; bol.com","en","conference paper","IEEE","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:361ceb9f-3765-4f9d-a474-ae89ba1aa70e","http://resolver.tudelft.nl/uuid:361ceb9f-3765-4f9d-a474-ae89ba1aa70e","On the Evaluation of NLP-based Models for Software Engineering","Izadi, M. (TU Delft Software Engineering); Ahmadabadi, Martin Nili (University of Tehran)","","2022","NLP-based models have been increasingly incorporated to address SE problems. These models are either employed in the SE domain with little to no change, or they are greatly tailored to source code and its unique characteristics. Many of these approaches are considered to be outperforming or complementing existing solutions. However, an important question arises here: Are these models evaluated fairly and consistently in the SE community?. To answer this question, we reviewed how NLP-based models for SE problems are being evaluated by researchers. The findings indicate that currently there is no consistent and widely-accepted protocol for the evaluation of these models. While different aspects of the same task are being assessed in different studies, metrics are defined based on custom choices, rather than a system, and finally, answers are collected and interpreted case by case. Consequently, there is a dire need to provide a methodological way of evaluating NLP-based models to have a consistent assessment and preserve the possibility of fair and efficient comparison.","Evaluation; Natural Language Processing; Software Engineering","en","conference paper","IEEE","","","","","","","","","","Software Engineering","","",""
"uuid:811771f1-d26b-4f25-a4a5-4b8e64362271","http://resolver.tudelft.nl/uuid:811771f1-d26b-4f25-a4a5-4b8e64362271","The Ethical Dimension of Emerging Technologies in Engineering Education","de Vries, P. (TU Delft System Engineering)","","2022","Emerging technologies are part of the constituting datafication and digitalization process that poses major challenges to the current educational infrastructure. Clearly, universities are challenged to respond to the demands that seem to develop faster and become more complex over time. The complexity, though, is not just technical; it is the combination of technology, and specifically big data use, with job requirements, educational practices, ethical responsibilities, and the socio-cultural aspects of education. The purpose of this paper is to analyze and discuss elements of these issues in trying to clarify the complexity and lower the threshold for those who are involved and to look for a better understanding of the opportunities and challenges. Therefore, different issues related to emerging technologies are discussed, with a focus on big data and artificial intelligence, as core technologies, followed by the impact of the COVID-19 pandemic as a societal development, the EdTech industry, and the ethical dimensions of the technological change and the consequences for education. Ethics have been shown to be of value, also, in times of increasing complexity and can guide the use and development of emerging technologies in higher education.","engineering education; emerging technologies; datafication; COVID-19; EdTech industry; ethics tech","en","journal article","","","","","","","","","","","System Engineering","","",""
"uuid:be8787b0-ea90-48fa-9c35-d8a732bb5102","http://resolver.tudelft.nl/uuid:be8787b0-ea90-48fa-9c35-d8a732bb5102","Teaching Design For Values: Concepts, Tools & Practices","","Rocco, Roberto (editor); Thomas, A.R. (editor); Novas, María (editor)","2022","The process of identifying, interpreting, and implementing societal values in university education is an essential part of responsible innovation and designing for equitable, inclusive, and sustainable societies. While there is now a well-defined and growing body of research on the theory and application of designing for values (or ‘value sensitive design’), at present the pedagogical dimension remains underexplored. Teaching Design for Values: A Companion is a resource for teachers of design-based disciplines who wish to foreground values more explicitly in their classes. With fourteen chapters written by both TU Delft educators and international contributors, the book aims to examine the concepts, methods and experiences of teaching design for values within a variety of fields, including urbanism, engineering, architecture, artificial intelligence and industrial design. Through its multi-disciplinarity, Teaching Design for Values proposes an expanded definition of ‘design’ to encompass a broad range of disciplines and processes that deal generally with ‘future-imagining’ and ‘futurebuilding’, including process management. In doing so it explores the ways that values may be expressed and analysed in a variety of different pedagogical contexts.","Responsible engineering; Values in design; Higher education; Value-based pedagogy","en","book","TU Delft OPEN Publishing","978-94-6366-635-0","","","","","","","","","Spatial Planning and Strategy","","",""
"uuid:8dd539e1-c38d-48bb-b926-d6324e9d2768","http://resolver.tudelft.nl/uuid:8dd539e1-c38d-48bb-b926-d6324e9d2768","Nalanda: a socio-technical graph platform for building software analytics tools at enterprise scale","Maddila, C.S. (Microsoft Research); Shanbhogue, Suhas (Microsoft Research); Agrawal, Apoorva (Microsoft Research); Zimmermann, Thomas (Microsoft Research); Bansal, Chetan (Microsoft Research); Forsgren, Nicole (Microsoft Research); Agrawal, Divyanshu (Microsoft Research); Herzig, Kim (Microsoft); van Deursen, A. (TU Delft Software Technology)","Roychoudhury, Abhik (editor); Cadar, Cristian (editor); Kim, Miryung (editor)","2022","Software development is information-dense knowledge work that requires collaboration with other developers and awareness of artifacts such as work items, pull requests, and file changes. With the speed of development increasing, information overload and information discovery are challenges for people developing and maintaining these systems. Finding information about similar code changes and experts is difficult for software engineers, especially when they work in large software systems or have just recently joined a project. In this paper, we build a large scale data platform named Nalanda platform to address the challenges of information overload and discovery. Nalanda contains two subsystems: (1) a large scale socio-technical graph system, named Nalanda graph system, and (2) a large scale index system, named Nalanda index system that aims at satisfying the information needs of software developers. To show the versatility of the Nalanda platform, we built two applications: (1) a software analytics application with a news feed named MyNalanda that has Daily Active Users (DAU) of 290 and Monthly Active Users (MAU) of 590, and (2) a recommendation system for related work items and pull requests that accomplished similar tasks (artifact recommendation) and a recommendation system for subject matter experts (expert recommendation), augmented by the Nalanda socio-technical graph. Initial studies of the two applications found that developers and engineering managers are favorable toward continued use of the news feed application for information discovery. The studies also found that developers agreed that a system like Nalanda artifact and expert recommendation application could reduce the time spent and the number of places needed to visit to find information.","Collaborative software development; Empirical study; Recommender Systems for Software Engineering; Socio-Technical Graphs","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","Software Technology","","","",""
"uuid:919245c7-3e45-4119-b5a8-48970cfad9c4","http://resolver.tudelft.nl/uuid:919245c7-3e45-4119-b5a8-48970cfad9c4","The Esiac-10 Algebraic Computer: A theoretical decomposition by the Historic Collection","Pronk, C. (TU Delft Software Engineering); Trimp, P.J. (TU Delft Electronic Instrumentation)","","2022","A description of the working pricciples of the Esiac-10 Algebraic Computer","algebraic compo=uter control engineering","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:ab9dd4c2-1da2-4828-aba3-6f7af7613067","http://resolver.tudelft.nl/uuid:ab9dd4c2-1da2-4828-aba3-6f7af7613067","Learning to Reframe Problems Through Moral Sensitivity and Critical Thinking in Environmental Ethics for Engineers","Gammon, A.R. (TU Delft Ethics & Philosophy of Technology); Marin, L. (TU Delft Ethics & Philosophy of Technology)","","2022","As attention to the pervasiveness and severity of environmental challenges grows, technical universities are responding to the need to include environmental topics in engineering curricula and to equip engineering students, without training in ethics, to understand and respond to the complex social and normative demands of these issues. But as compared to other areas of engineering ethics education, environmental ethics has received very little attention. This article aims to address this lack and raises the question: How should we teach environmental ethics to engineering students? We argue that one key aspect such teaching should address is the tendency of engineers towards technical framing of (social) problems. Drawing then on engineering ethics pedagogy we propose that the competencies of moral sensitivity and critical thinking can be developed to help engineering students with problem (re)framing. We conclude with an example from our teaching that operationalizes these competencies.","Moral sensitivity; engineering ethics education; environmental ethics education; problem framing; Critical thinking","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Ethics & Philosophy of Technology","","",""
"uuid:e3cbaad6-7498-4da4-bee3-b75c2a67b876","http://resolver.tudelft.nl/uuid:e3cbaad6-7498-4da4-bee3-b75c2a67b876","Alternative Energy Carriers in Naval Vessels","Streng, J.E. (Defence Materiel Organisation); Kana, A.A. (TU Delft Ship Design, Production and Operations); Verbaan, J.H. (Defence Materiel Organisation); Barendregt, I.P. (Defence Materiel Organisation); Hopman, J.J. (TU Delft Ship Design, Production and Operations)","","2022","In order to reduce fossil fuel consumption of the Royal Netherlands Navy (RNLN) by 70% in 2050, the use of alternative fuels on the large naval surface vessels is examined. This paper examines the implications for the design and operational effectiveness of these vessels by performing two case studies of the Zeven Provinci¨en air defence and command frigate (LCF) and the Johan de Witt landing platform dock (LPD). In the case studies an operational analysis, a parametric design study, and an effectiveness assessment are performed on multiple proposed designs. Results showed that it is possible to reduce the fossil fuel consumption of the RNLN by almost 70%. This does affect the design of the vessels, however. It was also concluded that the LPD is more suitable for the application of low-energy-density fuels than the LCF, due to its missions requirements. Both the LPD and the LCF show a significant increase in displacement and fuel cost, but it is possible to reduce effects on the operational effectiveness to a minimum.","Naval Vessels Design; Alternative Fuels; Energy Carriers; Marine Engineering; Ship Design","en","journal article","","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:18e8190e-4852-468d-aee5-ade4bced742e","http://resolver.tudelft.nl/uuid:18e8190e-4852-468d-aee5-ade4bced742e","Research on mathematical competencies in engineering education: Where are we now?","Wong, L.Y.J. (TU Delft Statistics); Papageorgiou, E. (TU Delft Statistics); Klaassen, R.G. (TU Delft Teaching & Learning Services); van der Wal, N.J. (TU Delft Statistics); Menschaart, L.E. (TU Delft Statistics); Cabo, A.J. (TU Delft Statistics)","Järvinen, Hannu-Matti (editor); Silvestre, Santiago (editor); Llorens, Ariadna (editor); Nagy, Balàzs (editor)","2022","In tertiary mathematics education for engineers (hereafter called service mathematics education, SME), there is a long-lasting controversy on what and how to teach. The goal of SME is to provide a base for engineering-specific courses and to develop mathematical competencies needed for academic success and professional practice. A leading question in engineering education is how to take mathematical competencies into account when designing content. Mathematical competencies are employed to understand, judge, do, and use mathematics in a variety of mathematical contexts and situations in which mathematics could play a role [1]. Although mathematical competencies have been introduced for about two decades, Alpers [2] noted that research in engineering higher education had focused chiefly on the modelling competency and less on other competencies. By means of a scoping review, the current study aims to examine how mathematical competencies are investigated in higher education research. The main research question is “To what extent and in what ways have mathematical competencies been examined in higher engineering education research?” Papers were retrieved and qualitatively reviewed using the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) guidelines. A systematic search yielded 166 records, of which, 65 unique records were relevant to engineering education and screened for eligibility. A synthesis of 23 studies reviewed showed that problem-solving and modelling were the most investigated mathematical competencies and were often investigated together or with other mathematical competencies. The inconsistencies in the terminologies used suggest a need for clearer conceptualizations to advance research and inform practice on mathematical competencies.","service mathematics; engineering education; mathematical competencies; scoping review; curriculum development","en","conference paper","","","","","","","","","","","Statistics","","",""
"uuid:c725169d-6752-4209-b379-ce406065406a","http://resolver.tudelft.nl/uuid:c725169d-6752-4209-b379-ce406065406a","An investigation on integration of computational thinking into engineering curriculum at delft university of technology","Zhang, X. (TU Delft Web Information Systems); Valle Torre, M. (TU Delft Web Information Systems); Specht, M.M. (TU Delft Web Information Systems)","Järvinen, Hannu-Matti (editor); Silvestre, Santiago (editor); Llorens, Ariadna (editor); Nagy, Balàzs (editor)","2022","Our life is surrounded by digital devices. Engineering education is one of the cornerstones in higher education for future generations and computational thinking (CT) is deemed as a core component in various engineering curricula. The Delft University of Technology (TU Delft), is the largest technical university in the Netherlands and computing; computational concepts and activities have been integrated into curriculum for years at TU Delft. However, there is not a comprehensive investigation on integration of CT into Engineering Curriculum, this paper presents a case study of Master’s level engineering curricula investigating: 1) to what extend CT components are integrated; 2) in what way CT is interpreted and integrated in the curriculum; 3) what educational and assessment methods have been used. The results show that CT has been largely integrated into the investigated curriculum mostly with lectures being the educational method and programming assignments as a method for the assessment. Our analysis shows that understanding the context and patterns in problems and solutions was important in different courses and engineering disciplines, indicating possible directions for integration of CT into curriculum.","Engineering Education; Computational Thinking; Curriculum; Case Study","en","conference paper","","","","","","","","","","","Web Information Systems","","",""
"uuid:04cfea8b-065b-4eed-bd21-882fdfe9e646","http://resolver.tudelft.nl/uuid:04cfea8b-065b-4eed-bd21-882fdfe9e646","An Adaptive Disturbance Decoupling Perspective to Longitudinal Platooning","Liu, Di (Southeast University; Rijksuniversiteit Groningen); Besselink, Bart (Rijksuniversiteit Groningen); Baldi, S. (TU Delft Team Bart De Schutter; Southeast University); Yu, Wenwu (Southeast University); Trentelman, Harry L. (Rijksuniversiteit Groningen)","","2022","Despite the progress in the field of longitudinal formations of automated vehicles, only recently an interpretation of longitudinal platooning has been given in the framework of disturbance decoupling, i.e. the problem of making a controlled output independent of a disturbance. The appealing feature of this interpretation is that the disturbance decoupling approach naturally yields a decentralized controller that guarantees stability and string stability. In this work, we further exploit the disturbance decoupling framework and we show that convergence to a stable, string stable and disturbance decoupled behavior can be achieved even in the presence of parametric uncertainty of the engine time constant. We refer to this framework as adaptive disturbance decoupling.","Adaptation models; Adaptive control; Asymptotic stability; Closed loop systems; Engines; Stability analysis; Vehicle dynamics","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Team Bart De Schutter","","",""
"uuid:e675faf3-0112-4a65-bea6-e6d3471f85be","http://resolver.tudelft.nl/uuid:e675faf3-0112-4a65-bea6-e6d3471f85be","Repentance as Rebuke: Betrayal and Moral Injury in Safety Engineering","Dekker, S.W.A. (TU Delft Control & Simulation; Griffith University); Layson, Mark D. (Charles Sturt University); Woods, David D. (Ohio State University)","","2022","Following other contributions about the MAX accidents to this journal, this paper explores the role of betrayal and moral injury in safety engineering related to the U.S. federal regulator’s role in approving the Boeing 737MAX—a plane involved in two crashes that together killed 346 people. It discusses the tension between humility and hubris when engineers are faced with complex systems that create ambiguity, uncertain judgements, and equivocal test results from unstructured situations. It considers the relationship between moral injury, principled outrage and rebuke when the technology ends up involved in disasters. It examines the corporate backdrop against which calls for enhanced employee voice are typically made, and argues that when engineers need to rely on various protections and moral inducements to ‘speak up,’ then the ethical essence of engineering—skepticism, testing, checking, and questioning—has already failed.","Accident; Betrayal; Boeing 737MAX; Engineering ethics; Federal Aviation Administration; Moral injury","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:4fe8f425-3b2c-41c3-a48f-b199eeea1279","http://resolver.tudelft.nl/uuid:4fe8f425-3b2c-41c3-a48f-b199eeea1279","Installation Penalty of Aero-Engines on Narrow Body Aircraft","Boogaart, T.E. (Student TU Delft); Hoogreef, M.F.M. (TU Delft Flight Performance and Propulsion); Gangoli Rao, A. (TU Delft Flight Performance and Propulsion)","","2022","Decades of improvements of engine efficiency on internal engine components through better materials, design methods and novel fabrication techniques have resulted in fuel consumption reductions. Another major factor for improving engine fuel consumption has been the increase of bypass ratio. However, this has a significant impact on engine dimensions and weight, and, consequently, the installation of the engine on the airframe.
Evaluation of engine installation penalties is not a new topic; literature provides various studies on aerodynamic effects. These primarily studied the effects of drag increase and the impact on drag of engine location and nacelle shape. This article investigates the performance impact of installation penalties from an increase in bypass ratio on narrow body aircraft, specifically the fuel consumption, weight and stability. Additionally,
an analysis is made comparing aircraft retrofit and redesign for increased bypass ratio engines. It can be concluded from retrofit analyses that engine size is more significant than its location. Changes in aerodynamic center, CLα , and CMAC cause stability/controllability criteria to shift to the left. Heavier engines at the same spanwise location cause a more forward CG location, which may become limiting. With the engine increasing in size (thus increasing the drag and increasing the weight), the overall increase in fuel burn is 5.9%. However,
the decrease in fuel burn due when the SFC and engine effects are considered together, the fuel burn drops by 50%. The reduction in fuel burn thereby negating the increase in engine weight, drag, and integration issues.
From BPR 10 onwards, the decreasing trend in tail size stagnates and actually reverses, indicating that larger tail sizes might be required for even larger BPR engines.","engine installation penalties; Aircraft design; aero-engine integration","en","conference paper","","","","","","","","","","","Flight Performance and Propulsion","","",""
"uuid:78b96ff4-9a16-4cce-aba4-a0a150373b90","http://resolver.tudelft.nl/uuid:78b96ff4-9a16-4cce-aba4-a0a150373b90","Interpretable neural network with limited weights for constructing simple and explainable HI using SHM data","Moradi, M. (TU Delft Structural Integrity & Composites); Komninos, P. (TU Delft Structural Integrity & Composites); Benedictus, R. (TU Delft Structural Integrity & Composites); Zarouchas, D. (TU Delft Structural Integrity & Composites)","Kulkarni, Chetan (editor); Saxena, Abhinav (editor)","2022","Recently, companies all over the world have been focusing on the improvement of autonomous health management systems in order to enhance performance and reduce downtime costs. To achieve this, the remaining useful life predictions have been given remarkable attention. These predictions depend on the proper designing process and the quality of health indicators (HI) generated from structural health monitoring sensors based on prior established multiple prognostic evaluation criteria. Constructing such HIs from noisy sensory data demands powerful models that enable the automatic selection and fusion of features taken from those relevant measurements. Deep learning models are promising to autonomously extract features in scenarios with a huge volume of data without requiring considerable domain expertise. Nonetheless, the features established by artificial neural networks are complicated to comprehend and cannot be regarded as physical system characteristics. In this regard, the goal of this paper is to extend a new model; an interpretable artificial neural network that enables the automatic selection and fusion of features to construct the most appropriate HIs with remarkably fewer parameters. This model consists of additive and multiplicative layers that provide a feature fusion that better reflects the system’s physical properties. Additionally, the weights are discretized in two ways: a) using a ternary form with values {-1, 0, 1}, and b) relaxing the aforementioned ternary form by rounding the weights at the first decimal point in the range of [-1, 1]. Both discretization techniques have the ability to softly control the number of parameters that should be ignored. This trick guarantees interpretability for the neural network by extracting simple yet powerful equations representing the constructed HIs. Finally, the model’s performance is evaluated and compared with other approaches using a practical case study. The results show that the proposed approach's designed HIs are both interpretable and of high quality according to the criteria of the HI's evaluation.","Prognostics and Health Management (PHM); Structural Health Monitoring (SHM); Intelligent health indicator; Interpretable neural network; C-MAPSS turbofan engines; Machine learning; Artificial Intelligent (AI)","en","conference paper","PHM Society","","","","","","","","","","Structural Integrity & Composites","","",""
"uuid:16667492-fee8-49c9-88ff-1f32745430aa","http://resolver.tudelft.nl/uuid:16667492-fee8-49c9-88ff-1f32745430aa","Crop Water Productivity Mapping and Benchmarking Using Remote Sensing and Google Earth Engine Cloud Computing","Ghorbanpour, Ali Karbalaye (University of California); Kisekka, Isaya (University of California); Afshar, Abbas (Iran University of Science and Technology); Hessels, T.M. (TU Delft Water Resources); Taraghi, Mahdi (Urmia University); Hessari, Behzad (Urmia University); Tourian, Mohammad J. (University of Stuttgart); Duan, Zheng (Lund University)","","2022","Scarce water resources present a major hindrance to ensuring food security. Crop water productivity (WP), embraced as one of the Sustainable Development Goals (SDGs), is playing an integral role in the performance-based evaluation of agricultural systems and securing sustainable food production. This study aims at developing a cloud-based model within the Google Earth Engine (GEE) based on Landsat -7 and -8 satellite imagery to facilitate WP mapping at regional scales (30-m resolution) and analyzing the state of the water use efficiency and productivity of the agricultural sector as a means of benchmarking its WP and defining local gaps and targets at spatiotemporal scales. The model was tested in three major agricultural districts in the Lake Urmia Basin (LUB) with respect to five crop types, including irrigated wheat, rainfed wheat, apples, grapes, alfalfa, and sugar beets as the major grown crops. The actual evapotranspiration (ET) was estimated using geeSEBAL based on the Surface Energy Balance Algorithm for Land (SEBAL) methodology, while for crop yield estimations Monteith’s Light Use Efficiency model (LUE) was employed. The results indicate that the WP in the LUB is below its optimum targets, revealing that there is a significant degree of work necessary to ameliorate the WP in the LUB. The WP varies between 0.49–0.55 (kg/m3) for irrigated wheat, 0.27–0.34 for rainfed wheat, 1.7–2.2 for apples, 1.2–1.7 for grapes, 5.5–6.2 for sugar beets, and 0.67–1.08 for alfalfa, which could be potentially increased up to 80%, 150%, 76%, 83%, 55%, and 48%, respectively. The spatial variation of the WP and crop yield makes it feasible to detect the areas with the best and poorest on-farm practices, thereby facilitating the better targeting of resources to bridge the WP gap through water management practices. This study provides important insights into the status and potential of WP with possible worldwide applications at both farm and government levels for policymakers, practitioners, and growers to adopt effective policy guidelines and improve on-farm practices.","crop water productivity; Google Earth Engine; Lake Urmia; Landsat; remote sensing; SEBAL","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:2c3ff6cc-1967-4f95-9509-cd597d252fa1","http://resolver.tudelft.nl/uuid:2c3ff6cc-1967-4f95-9509-cd597d252fa1","Engineering Laboratory Experiments–a Typology","Zwart, S.D. (TU Delft Ethics & Philosophy of Technology)","","2022","With the introduction of large commercial industrial laboratories at the end of the nineteenth century, many types of experiments were institutionalized that do not aim at testing hypotheses. This paper builds a typology of experiments in techno-science, by analysing more than two hundred and fifty real-life technical projects. This resulted in four testing types (tests of hypotheses, of designs, of means-end knowledge, and of models or software), three determining types (developing working principles, preferred actions, and determining values of variables or relationships between variables) and one trial-and-error type of pure exploration. The typology is developed by working back and forth between thick descriptions of the experiments including their goals, and the development of six criteria of differentiation, to wit: determining versus testing; measurement scales of (in)dependent variables; intrinsic versus instrumental value of the outcomes; proximate function of the outcome; distant role of the outcome in the embedded project; the descriptive or normative character of the proximate or distant outcomes. The typology opens up inspiring methodological and philosophical research questions.","criteria of differentiation; engineering; epistemic and action-guiding experiments; exploratory; hierarchical project plans; ideal types of experiments; Laboratory experiment; levels of description; theory-driven; thick descriptions of experiments; typology","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:92b26f78-d495-446f-9281-fdc08410fd77","http://resolver.tudelft.nl/uuid:92b26f78-d495-446f-9281-fdc08410fd77","Cellular assays identify barriers impeding iron-sulfur enzyme activity in a non-native prokaryotic host","D'Angelo, Francesca (Université de Paris); Fernandez Fueyo, E. (TU Delft BN/Greg Bokinsky Lab; Kavli institute of nanoscience Delft); Garcia, Pierre Simon (Université de Paris); Shomar Monges, H. (TU Delft BN/Greg Bokinsky Lab; Kavli institute of nanoscience Delft); Cebola Rebelo Manuel, R.S. (TU Delft BN/Greg Bokinsky Lab; Kavli institute of nanoscience Delft); Büke, F. (TU Delft BN/Greg Bokinsky Lab; Kavli institute of nanoscience Delft); van den Broek, N.J.F. (TU Delft BN/Greg Bokinsky Lab; Kavli institute of nanoscience Delft); de Ram, C. (TU Delft BT/Environmental Biotechnology); Pabst, Martin (TU Delft BT/Environmental Biotechnology)","","2022","Iron-sulfur (Fe-S) clusters are ancient and ubiquitous protein cofactors and play irreplaceable roles in many metabolic and regulatory processes. Fe-S clusters are built and distributed to Fe-S enzymes by dedicated protein networks. The core components of these networks are widely conserved and highly versatile. However, Fe-S proteins and enzymes are often inactive outside their native host species. We sought to systematically investigate the compatibility of Fe-S networks with non-native Fe-S enzymes. By using collections of Fe-S enzyme orthologs representative of the entire range of prokaryotic diversity, we uncovered a striking correlation between phylogenetic distance and probability of functional expression. Moreover, coexpression of a heterologous Fe-S biogenesis pathway increases the phylogenetic range of orthologs that can be supported by the foreign host. We also find that Fe-S enzymes that require specific electron carrier proteins are rarely functionally expressed unless their taxon-specific reducing partners are identified and co-expressed. We demonstrate how these principles can be applied to improve the activity of a radical S-adenosyl methionine(rSAM) enzyme from a Streptomyces antibiotic biosynthesis pathway in Escherichia coli. Our results clarify how oxygen sensitivity and incompatibilities with foreign Fe-S and electron transfer networks each impede heterologous activity. In particular, identifying compatible electron transfer proteins and heterologous Fe-S biogenesis pathways may prove essential for engineering functional Fe-S enzyme-dependent pathways.","biochemistry; chemical biology; electron transfer protein; escherichia coli; horizontal gene transfer; infectious disease; iron-sulfur enzyme; microbial engineering; microbiology","en","journal article","","","","","","","","","","","BN/Greg Bokinsky Lab","","",""
"uuid:55d10208-6f1b-4652-9a68-ba66018372f0","http://resolver.tudelft.nl/uuid:55d10208-6f1b-4652-9a68-ba66018372f0","Magneto‐/ electro‐responsive polymers toward manufacturing, characterization, and biomedical/ soft robotic applications","Yarali, E. (University of Tehran); Baniasadi, Mahdi (University of Tehran); Zolfagharian, Ali (Deakin University); Chavoshi, Maede (University of Tehran); Arefi, Fatemeh (University of Tehran); Hossain, Mokarram (Swansea University); Bastola, Anil (University of Nottingham); Ansari, Mahdi (Arak University of Technology); Foyouzat, Alireza (University of Tehran); Dabbagh, Ali (University of Tehran); Ebrahimi, Mohamad (University of Calgary); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Bodaghi, Mahdi (Nottingham Trent University)","","2022","Magneto-/ electro-responsive polymers (MERPs) are a class of stimuli-responsive materials that are actuated when triggered by external magnetic/ electric fields. MERPs exhibit rapid, reversible, and safe multi-functional and dynamic (i.e., changing with time) properties, which can effectively be manipulated at different length scales. These features make MERPs very attractive particularly in biomedical engineering (e.g., drug delivery systems and tissue engineering), soft matter engineering (e.g., soft robotics), and structural design of smart materials with unprecedented properties (e.g., complex shape morphing). Due to the recent progress in the design and development of MERPs, here, we highlighted the current advances in fabricating MERPs using various manufacturing methods including 3D/ 4D printing and conventional techniques. We also summarized the methods used for the characterization of MERPs and discussed their important structure-property relationship. We also highlighted the potential applications of MERPs in biomedical engineering, soft robotic, and the design of smart materials and systems. MERPs show great potentials for creating smart materials with predictable dynamic properties. More studies are necessary to investigate the biological responses of MERP both in-vivo and in-vitro, which is essential for biomedical engineering applications.","3D/4D printing; Drug delivery systems; Magneto-/ electro-responsive polymers; Shape morphing; Soft robotics; Tissue engineering","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:46bd6d0b-a545-4701-a502-4a919a6c5ab8","http://resolver.tudelft.nl/uuid:46bd6d0b-a545-4701-a502-4a919a6c5ab8","Investigating factors related to ethical expectations and motivations among Chinese engineering students","Clancy III, R.F. (TU Delft Ethics & Philosophy of Technology; Shanghai Jiao Tong University); Ge, Yan (Shanghai Jiao Tong University); An, Longfei (Institute of Social Cognition and Decision-making)","","2022","Research in engineering ethics has examined the effects of education on the ethical knowledge and reasoning of students from mostly WEIRD (Western educated industrialized rich democratic) cultures. However, it is unclear that findings from WEIRD samples are transferable across cultures. China now graduates and employs more STEM (science technology engineering mathematics) majors than any other country, although little work has examined the ethical perspectives and education of these students. Therefore, a study was conducted exploring the kinds of ethical issues Chinese engineering students expect to encounter (expectations), the importance they attach to being ethical (motivations), and their relations to various curricular and extra-curricular factors, including sources of ethical influence, nature and extent of ethics education, and perceived usefulness of ethics education. 163 Chinese engineering majors from two Chinese-foreign educational institutes in Shanghai, China completed a survey. Results indicate participants were most likely to expect to face ethical issues related to fairness, and that the perceived usefulness of ethics education was predictive of both ethical expectations and motivations, followed by encountering instructors who cared about ethics. The extent of ethics education was related to ethical expectations but not motivations. The implications of these findings and directions for future work are discussed.","China; cultural psychology; Engineering ethics; ethics education; global engineering ethics; non-weird","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:110166ee-8489-4fab-b6a5-cac2331ea21a","http://resolver.tudelft.nl/uuid:110166ee-8489-4fab-b6a5-cac2331ea21a","CTE-STEM 2022: Proceedings of Sixth APSCE International Conference on Computational Thinking and STEM Education 2022","","Zhang, X. (editor); Glahn, C. (editor); Fanchamps, L.J.A. (editor); Specht, M.M. (editor)","2022","","Computational Thinking; Concepts; Reviews; Programming; Teachers; Games; Education; STEM (Science, Technology, Engineering, Mathematics)","en","book","TU Delft OPEN Publishing","978-94-6366-563-6","","","","","","","","","Web Information Systems","","",""
"uuid:ce3565aa-8462-4011-a8ae-4bd0bcb34eda","http://resolver.tudelft.nl/uuid:ce3565aa-8462-4011-a8ae-4bd0bcb34eda","Climate Impact Mitigation Potential of Novel Aircraft Features","Barner, N.M. (Student TU Delft); Ghafourpour, L.D. (Student TU Delft); Güverte, M.S. (Student TU Delft); Modesti, D. (TU Delft Aerodynamics); Hulshoff, S.J. (TU Delft Aerodynamics)","","2022","This work presents a transpacific airliner designed for minimal climate impact, incorporating several novel design features. These include open rotor engines, sustainable aviation fuels, natural laminar flow airfoils, and riblets. The design’s configuration and mission have been optimised simultaneously using a combination of standard preliminary techniques, experimental data, a multi-point mission analysis, and a model of average temperature response. It is demonstrated that, on an 8000 km mission, the design offers an 89.8% reduction in average temperature response relative to an Airbus A330-200, at the expense of a 7.3% increase in direct operating cost. The sensitivity of these results is investigated by comparing the performance over a range of operating conditions. In addition, several alternative designs incorporating only some of the above-mentioned features are analysed, allowing for an assessment of their individual contribution. Finally, a life-cycle average temperature response analysis is presented to place the climate impact of operation, manufacturing and end-of-life procedures in context","average temperature response; direct operating cost; sustainable aircraft design; mission optimisation; open rotor engines; natural laminar flow; riblets","en","journal article","","","","","","","","","","","Aerodynamics","","",""
"uuid:3704014b-962c-489b-98e2-74aa84a4bdd7","http://resolver.tudelft.nl/uuid:3704014b-962c-489b-98e2-74aa84a4bdd7","Sustainable and Resilient Coastal Cities (SARCC): Interdisciplinary Flood Protection Strategies for Southend-on-Sea (UK)","Wüthrich, D. (TU Delft Hydraulic Structures and Flood Risk); Teng, Djimin (Student TU Delft); Ke, Q. (TU Delft Hydraulic Structures and Flood Risk); Diaz, Andres (JBA Consulting); Bortolotti, A. (TU Delft Environmental Technology and Design); Iuorio, Luca (TU Delft Environmental Technology and Design); Hooimeijer, F.L. (TU Delft Environmental Technology and Design)","Ortega-Sanchez, Miguel (editor)","2022","In a world influenced by climate change and consequently sea-level rise, extreme floods are expected to become more frequent in the future, representing a serious threat for riverine and coastal settlements. Therefore, flood protection is a large component of climate adaptation and should be closely related to other measures of climate adaptation and societal needs. In this context, SARCC (Sustainable And Resilient Coastal Cities) supports the use of integrated Nature Based Solutions into coastal management, urban planning and design, integrating them into existing infrastructure and flood defenses. This paper will focus on the strategy developed for Southend-On-Sea (UK), presenting the different approaches that were used to manage coastal flooding and make it part of a long-term large scale urban development strategy. In particular, this study estimated overtopping discharges during extreme storm conditions and analyzed their inland propagation using Delft3D FM numerical simulations. Based on these results, mitigation, and adaptation measures as a part of the spatial strategy were developed through a joint collaboration of hydraulic engineers, urban designers, maritime archaeologists and local authorities, pointing out the strength of interdisciplinary approaches for reliable and well-integrated flood protection strategies. Important highlight of the study is how flood risk management is integrated in spatial planning and how hydraulic engineering modeling is directly use as indicators to make spatial design decisions.","Flood protection; hydraulic engineering; urban planning; resilient cities; interdisciplinary approach","en","conference paper","IAHR","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Hydraulic Structures and Flood Risk","","",""
"uuid:77e5abb9-1fa5-4f37-81bb-42ebc2a0e594","http://resolver.tudelft.nl/uuid:77e5abb9-1fa5-4f37-81bb-42ebc2a0e594","Risk, Uncertainty, and Ignorance in Engineering Systems Design","Oehmen, Josef (Technical University of Denmark); Kwakkel, J.H. (TU Delft Policy Analysis)","","2022","Uncertainty is the third major perspective in understanding and designing engineering systems, along with complexity and human behaviour. Risk, a corollary of uncertainty, is understood as the effect of uncertainty on objectives. When designing engineering systems, you cannot not manage risk - even ignoring risk equates to a decision to accept it. Engineering systems are characterised by long life cycles, changing operational environments, and evolving stakeholder values, leading to a wide range of uncertainties in their design and operation. Productively engaging with this uncertainty is critical for successfully operating and especially (re-)designing engineering systems. This chapter provides an overview of managerial practices to address the three levels of increasing uncertainty in engineering systems design: from (1) managing risk, to (2) managing uncertainty, to (3) managing ignorance. We differentiate for each level of uncertainty between two levels of value diversity: (1) primarily commensurate values (i.e. agreement on core values by critical stakeholders) and (2) primarily incommensurate values (i.e. no agreement on core values). The managerial practices we discuss are “classic” risk management, public engagement, scenario planning, robust decision-making, resilience, and applying the precautionary principle. In addition, we briefly illuminate the actuality of management practices dealing with the different levels of uncertainty beyond explicit, formal processes, the understanding of managing uncertainty as both modelling and decision support practices and personal and organisational biases in the context of addressing uncertainty.","Engineering systems; Engineering systems design; Resilience; Risk management; Robust decision-making","en","book chapter","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-01-31","","","Policy Analysis","","",""
"uuid:f6b97d2f-0c48-4748-b5d5-2ac49578729d","http://resolver.tudelft.nl/uuid:f6b97d2f-0c48-4748-b5d5-2ac49578729d","Improving the performance of civil engineering projects through the integrated design process","Keusters, A.C.A.M. (TU Delft Integral Design & Management); Bakker, H.L.M. (TU Delft Integral Design & Management); Houwing, E.J. (TU Delft Integral Design & Management)","","2022","Purpose: Civil engineering projects around the world have been underperforming for a long time. While the complexity of these projects will continue to increase, there is an urgent need to perform better. Although the integrated design process is critical for project success, the literature lacks studies describing the link to project performance. Therefore, this study aims to investigate the dominant variables that affect the integrated design process and consequently project performance. Design/methodology/approach: A multiple case study was conducted to determine the dominant variables that affect the integrated design process and project performance. The research included four projects. Semi-structured interviews were the main source of data. Findings: The cases indicated that the extent to which an integrated approach is achieved in the design process is essential for project performance. This applies to the integration of stakeholders’ interests as well as the integration of disciplines. Above all, it was concluded that the project team participants’ competencies for integration are a dominant factor for project performance, as the integrated design process has changed from a technical challenge to an integrative one. Originality/value: This study provides insights into the dominant variable of the integrated design process that affects project performance, which is underexposed in the literature. The study results reveal the importance of competencies related to integration and adoption of the design problem context, which are not yet included in civil engineering design methods. In this respect, empathy is introduced as a new and critical competence for the civil engineering industry, which needs further research.","Complexity; Design; Human factors engineering; Integrated design; Project performance","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-07-27","","","Integral Design & Management","","",""
"uuid:0f1cfd2e-87a5-4c34-b9ba-8d4c33eadfd4","http://resolver.tudelft.nl/uuid:0f1cfd2e-87a5-4c34-b9ba-8d4c33eadfd4","Using an industry instrument to trigger the improvement of the transversal competency learning outcomes of engineering graduates","Leandro Cruz, M. (TU Delft Novel Aerospace Materials); Saunders-Smits, Gillian (TU Delft Aerospace Structures & Materials)","","2022","To assist in resolving the perceived lack of transversal competencies (TCs) of engineering graduates by industry, this study investigates the characteristics of transforming an existing industry TC instrument for use in engineering education. The instrument consists of 36 nuanced sub-competencies with the corresponding definitions and descriptive mastery levels. This instrument was first used to determine required TCs mastery levels for BSc and MSc graduates by European industry and subsequently, using two representative curricula as case studies to map TCs course outcomes and lecturer perceptions of TCs course outcomes, using interviews for further exploration. The main findings are that the TC instrument is suitable to determine desired industry mastery levels as well as to map TCs course outcomes both in formal documentation and by lecturers. Also, a gap between the formal and perceived curriculum was found i.e. discrepancies in reported TC learning outcomes between formal documentation and lecturer-reported TCs in courses.","employability; Engineering Education; industry perception; lecturer perception; Transversal competency levels","en","journal article","","","","","","","","","","Aerospace Structures & Materials","Novel Aerospace Materials","","",""
"uuid:913b61e4-dfa6-4537-a7ac-e7937f10918d","http://resolver.tudelft.nl/uuid:913b61e4-dfa6-4537-a7ac-e7937f10918d","Physical and Data-Driven Models Hybridisation for Modelling the Dynamic State of a Four-Stroke Marine Diesel Engine","Coraddu, A. (TU Delft Ship Design, Production and Operations); Kalikatzarakis, Miltiadis (University of Strathclyde); Theotokatos, Gerasimos (University of Strathclyde); Geertsma, R.D. (TU Delft Ship Design, Production and Operations; Netherlands Defence Academy); Oneto, Luca (University of Genova)","Kumar Agarwal, Avinash (editor); Kumar, Dhananjay (editor); Sharma, Nikhil (editor); Sonawane, Utkarsha (editor)","2022","Accurate, reliable, and computationally inexpensive models of the dynamic state of combustion engines are a fundamental tool to investigate new engine designs, develop optimal control strategies, and monitor their performance. The use of those models would allow to improve the engine cost-efficiency trade-off, operational robustness, and environmental impact. To address this challenge, two state-of-the-art alternatives in literature exist. The first one is to develop high fidelity physical models (e.g., mean value engine, zero-dimensional, and one-dimensional models) exploiting the physical principles that regulate engine behaviour. The second one is to exploit historical data produced by the modern engine control and automation systems or by high-fidelity simulators to feed data-driven models (e.g., shallow and deep machine learning models) able to learn an accurate digital twin of the system without any prior knowledge. The main issues of the former approach are its complexity and the high (in some case prohibitive) computational requirements. While the main issues of the latter approach are the unpredictability of their behaviour (guarantees can be proved only for their average behaviour) and the need for large amount of historical data. In this work, following a recent promising line of research, we describe a modelling framework that is able to hybridise physical and data driven models, delivering a solution able to take the best of the two approaches, resulting in accurate, reliable, and computationally inexpensive models. In particular, we will focus on modelling the dynamic state of a four-stroke diesel engine testing the performance (both in terms of accuracy, reliability, and computational requirements) of this solution against state-of-the-art physical modelling approaches on real-world operational data.","Data-driven models; Hybridisation; Marine diesel engine; Physical models","en","book chapter","Springer","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Ship Design, Production and Operations","","",""
"uuid:a5f7ad93-17e1-4080-b14c-fddbc8018cc7","http://resolver.tudelft.nl/uuid:a5f7ad93-17e1-4080-b14c-fddbc8018cc7","Modular, synthetic chromosomes as new tools for large scale engineering of metabolism","Postma, E.D. (TU Delft BT/Industriele Microbiologie); Else-Hassing, J. (TU Delft BT/Industriele Microbiologie); Mangkusaputra, Venda (Student TU Delft); Geelhoed, J. (TU Delft BT/Industriele Microbiologie); de la Torre, P. (TU Delft BT/Industriele Microbiologie); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Mooiman, C. (TU Delft BT/Bioprocess Engineering); Pabst, Martin (TU Delft BT/Environmental Biotechnology); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Daran-Lapujade, P.A.S. (TU Delft BT/Industriele Microbiologie)","","2022","The construction of powerful cell factories requires intensive genetic engineering for the addition of new functionalities and the remodeling of native pathways and processes. The present study demonstrates the feasibility of extensive genome reprogramming using modular, specialized de novo-assembled neochromosomes in yeast. The in vivo assembly of linear and circular neochromosomes, carrying 20 native and 21 heterologous genes, enabled the first de novo production in a microbial cell factory of anthocyanins, plant compounds with a broad range of pharmacological properties. Turned into exclusive expression platforms for heterologous and essential metabolic routes, the neochromosomes mimic native chromosomes regarding mitotic and genetic stability, copy number, harmlessness for the host and editability by CRISPR/Cas9. This study paves the way for future microbial cell factories with modular genomes in which core metabolic networks, localized on satellite, specialized neochromosomes can be swapped for alternative configurations and serve as landing pads for the addition of functionalities.","Anthocyanin; Designer chromosome; Genome engineering; Metabolic engineering; Saccharomyces cerevisiae","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:9f68ba7d-e291-43ac-b6e1-7a1d7c429074","http://resolver.tudelft.nl/uuid:9f68ba7d-e291-43ac-b6e1-7a1d7c429074","Wind load estimation and virtual sensing in long-span suspension bridges using physics-informed Gaussian process latent force models","Petersen, W. (Norwegian University of Science and Technology (NTNU)); Øiseth, O. (Norwegian University of Science and Technology (NTNU)); Lourens, E. (TU Delft Dynamics of Structures; TU Delft Offshore Engineering)","","2022","Wind loading is an essential aspect in the design and assessment of long-span bridges, but it is often not well-known and cannot be measured directly. Most structural health monitoring systems can easily measure structural responses at discrete locations using accelerometers. This data can be combined with reduced-order modal models in Kalman filter-based algorithms for an inverse estimation of wind loads and system states. As a further development, this work investigates the incorporation of Gaussian process latent force models (GP-LFMs), which can characterize the evolution of the wind loading. The Hardanger Bridge, a 1310 m long suspension bridge instrumented with a monitoring system for wind and vibrations, is used as a case study. It is shown how the LFMs can be enriched with physical information about the stochastic wind loads using monitoring anemometer data and aerodynamic coefficients from wind tunnel tests. It is found that the estimates of the modal wind loads and modal states obtained from a Kalman filter and Rauch–Tung–Striebel smoother are stable for acceleration output only, thus avoiding the accumulation of errors. The proposed approach demonstrates how physical or environmental data can be injected as valuable information for global monitoring strategies and virtual sensing in bridges.","Force identification; Gaussian process; Latent force model; Response prediction; Structural monitoring; Suspension bridge; Virtual sensing; Wind engineering","en","journal article","","","","","","","","","","","Dynamics of Structures","","",""
"uuid:57cb2a92-5345-4747-97ec-8b9e1c5cd911","http://resolver.tudelft.nl/uuid:57cb2a92-5345-4747-97ec-8b9e1c5cd911","Unraveling electron liberation from Bi2+ for designing Bi3+-based afterglow phosphor for anti-counterfeiting and flexible X-ray imaging","Lyu, T. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials); Li, Canhua (Huaqiao University, Xiamen); Li, Silei (Huaqiao University, Xiamen); Xu, Jian (National Institute for Materials Science); Wei, Zhanhua (Huaqiao University, Xiamen)","","2022","It is challenging to rational design persistent luminescence and storage phosphors with high storage capacity of electrons and holes after X-ray charging. Such phosphors have potential applications in anti-counterfeiting and X-ray imaging. Here we have combined vacuum referred binding energy diagram (VRBE) construction, photoluminescence spectroscopy, and thermoluminescence to study the trapping processes of charge carriers in NaYGeO4. In NaYGeO4:0.004Bi3+ and NaYGeO4:0.004Bi3+,0.005Ln3+ (Ln = Tb or Pr), Bi3+ appears to act as a shallow electron trap, while Bi3+ and Ln3+ act as deep hole trapping and recombination centres. We will show how to experimentally determine the VRBE in the Bi2+ 2P1/2 ground state in NaYGeO4 and NaLuGeO4 by thermoluminescence study. The electron trap depth produced by Bi3+ codopant in NaLu1-xYxGeO4:0.003Bi3+,0.008 Tb3+ can be adjusted, by increasing x, resulting in conduction band engineering. By combining Bi3+ as an electron trap and Bi3+ and Tb3+ as the hole traps, excellent X-ray charged afterglow phosphors were developed. The integrated TL intensity of the optimized NaYGeO4:0.004Bi3+ and NaYGeO4:0.003Bi3+,0.008Tb3+ after exposure to X-rays is about 4.5 and 1.1 times higher than that of the state-of-the-art BaFBr(I):Eu2+ storage phosphor. Intense initial Tb3+ 4f → 4f afterglow appears in NaYGeO4:0.003Bi3+,0.008Tb3+ and more than 40 h afterglow is measurable in NaYGeO4:0.004Bi3+ and NaYGeO4:0.003Bi3+, 0.008 Tb3+ after X-ray charging. We will show proof-of-concept anti-counterfeiting and X-ray imaging applications by using the developed afterglow phosphors and CsPbI3 quantum dots. This work not only provides experimental evidence on the VRBE in the Bi2+ 2P1/2 ground state in NaYGeO4, but also shows how to design and develop good afterglow phosphors for anti-counterfeiting and X-ray imaging by deeply studying and controlling the trapping processes of charge carriers in bismuth and/or lanthanides doped inorganic compounds.","Bi VRBE; Bismuth; Electron liberation from Bi; Electron trap depth engineering; X-ray imaging","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","RST/Luminescence Materials","","",""
"uuid:bece3a70-3e53-43a5-b51a-50904a243c41","http://resolver.tudelft.nl/uuid:bece3a70-3e53-43a5-b51a-50904a243c41","Mean value first principle engine model for predicting dynamic behaviour of two-stroke marine diesel engine in various ship propulsion operations","Sui, Congbiao (TU Delft Ship Design, Production and Operations; Harbin Engineering University); de Vos, P. (TU Delft Ship Design, Production and Operations); Stapersma, D. (TU Delft Ship Design, Production and Operations); Visser, K. (TU Delft Ship Design, Production and Operations); Hopman, J.J. (TU Delft Ship Design, Production and Operations); Ding, Yu (Harbin Engineering University)","","2022","Analysis of ship propulsion system performance is often performed using detailed hydrodynamic models to assess load changes, which are subsequently compared to static engine limits, or by detailed engine models that are rarely integrated with sufficiently detailed propulsion models for load change estimation. To investigate the dynamic engine (overloading) behaviour and ship propulsion performance under various heavy operating conditions, a Mean Value First Principle Parametric (MVFPP) engine model is integrated into a ship propulsion system model in this paper. An upgraded thermodynamic-based MVFPP model for two-stroke marine diesel engines is presented, in particular a newly developed MVFPP gas exchange model. Based on the integrated propulsion system model of a benchmark ocean-going chemical tanker, the engine dynamic behaviour during ship acceleration, deceleration and crash stop has been investigated. Results show that, during dynamic processes, the engine could be thermally overloaded even if the engine power trajectory is inside the static engine operating envelope. The paper contributes to finding proper indicators for thermal overloading of modern two-stroke marine diesel engines. It is demonstrated that when matching the engine with the propeller and designing the ship propulsion control system, not only the static engine operating envelope, but also the dynamic engine behaviour should be considered.","1D ship propulsion system model; Engine dynamic performance; Thermal loading; Two-stroke marine diesel engine mean value first principle model; Two-zone scavenge model","en","journal article","","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:719f0bdd-932b-431f-8b60-0b8504c8426a","http://resolver.tudelft.nl/uuid:719f0bdd-932b-431f-8b60-0b8504c8426a","Pathway engineering strategies for improved product yield in yeast-based industrial ethanol production","van Aalst, A.C.A. (TU Delft BT/Industriele Microbiologie); de Valk, S.C. (TU Delft BT/Industriele Microbiologie); van Gulik, W.M. (TU Delft BT/Industriele Microbiologie); Jansen, Mickel L.A. (DSM); Pronk, J.T. (TU Delft BT/Biotechnologie); Mans, R. (TU Delft BT/Industriele Microbiologie)","","2022","Product yield on carbohydrate feedstocks is a key performance indicator for industrial ethanol production with the yeast Saccharomyces cerevisiae. This paper reviews pathway engineering strategies for improving ethanol yield on glucose and/or sucrose in anaerobic cultures of this yeast by altering the ratio of ethanol production, yeast growth and glycerol formation. Particular attention is paid to strategies aimed at altering energy coupling of alcoholic fermentation and to strategies for altering redox-cofactor coupling in carbon and nitrogen metabolism that aim to reduce or eliminate the role of glycerol formation in anaerobic redox metabolism. In addition to providing an overview of scientific advances we discuss context dependency, theoretical impact and potential for industrial application of different proposed and developed strategies.","Biofuels; Energy metabolism; Metabolic engineering; Redox metabolism; Saccharomyces cerevisiae; Synthetic biology","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:0c514165-12f6-41df-95b1-285cf3af065b","http://resolver.tudelft.nl/uuid:0c514165-12f6-41df-95b1-285cf3af065b","Biochemistry shapes growth kinetics of nitrifiers and defines their activity under specific environmental conditions","Martinez-Rabert, Eloi (University of Glasgow); Smith, Cindy J. (University of Glasgow); Sloan, William T. (University of Glasgow); Gonzalez Cabaleiro, R. (TU Delft BT/Environmental Biotechnology)","","2022","Is it possible to find trends between the parameters that define microbial growth to help us explain the vast microbial diversity? Through an extensive database of kinetic parameters of nitrifiers, we analyzed if the dominance of specific populations of nitrifiers could be predicted and explained. We concluded that, in general, higher growth yield (YXS) and ammonia affinity (a0NH3) and lower growth rate (µmax) are observed for ammonia-oxidizing archaea (AOA) than bacteria (AOB), which would explain their considered dominance in oligotrophic environments. However, comammox (CMX), with the maximum energy harvest per mole of ammonia, and some AOB, have higher a0NH3 and lower µmax than some AOA. Although we were able to correlate the presence of specific terminal oxidases with observed oxygen affinities (a0O2) for nitrite-oxidizing bacteria (NOB), that correlation was not observed for AOB. Moreover, the presumed dominance of AOB over NOB in O2-limiting environments is discussed. Additionally, lower statistical variance of a0O2 values than for ammonia and nitrite affinities was observed, suggesting nitrogen limitation as a stronger selective pressure. Overall, specific growth strategies within nitrifying groups were not identified through the reported kinetic parameters, which might suggest that mostly, fundamental differences in biochemistry are responsible for underlying kinetic parameters.","environmental engineering; kinetic parameters; microbial interaction; nitrifiers","en","journal article","","","","","","","","","","","BT/Environmental Biotechnology","","",""
"uuid:5ece17ef-902f-40af-af9a-bd22a89da055","http://resolver.tudelft.nl/uuid:5ece17ef-902f-40af-af9a-bd22a89da055","Chemical process safety education in China: An overview and the way forward","Motalifu, Mailidan (China University of Petroleum (East China)); Tian, Yue (Sinochem); Liu, Yi (China University of Petroleum (East China)); Zhao, Dongfeng (China University of Petroleum (East China)); Bai, Mingqi (China University of Petroleum (East China)); Kan, Yufeng (Wanhua Chemical Group); Qi, Meng (Yonsei University); Reniers, G.L.L.M.E. (TU Delft Safety and Security Science); Roy, Nitin (California State University)","","2022","The chemical process industry (CPI) in China is developing rapidly with installations becoming more complicated and integrated to meet people's rising demands for chemical-related products. However, the fast-growing CPI has caused catastrophic consequences and bad social influence due to accidents occurred in the last decades, which has threatened its sustainable development. As one of the solutions, the Chinese government is promoting chemical process safety education to train interdisciplinary graduates who understand both chemical process and loss prevention, who are skilled in technology, and how to manage risk. In this paper, we reviewed the development of chemical process safety education in China by researching syllabuses of accredited undergraduate Chemical Engineering and Safety Engineering majors in higher education institutions, discussed the associated shortcomings by analyzing the current discipline construction of the newly established major Chemical Safety Engineering, including education methodologies, resources, faculties, curriculum provision, and professional accreditation. Based on the analysis results, suggestions were provided to encourage institutions to strengthen chemical process safety education, thereby inherently reducing human errors and consequently improving the safety of the entire CPI.","Chemical engineering; Chemical process industry; Engineering education accreditation; Interdisciplinary graduates","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Safety and Security Science","","",""
"uuid:7c82e67f-b363-4e46-8d1f-e8d5c1f468f7","http://resolver.tudelft.nl/uuid:7c82e67f-b363-4e46-8d1f-e8d5c1f468f7","An overview of induced seismicity in the Netherlands","Muntendam-Bos, A.G. (TU Delft Applied Geology); Hoedeman, Gerco (Staatstoezicht op de Mijnen); Polychronopoulou, Katerina (Seismotech S.A.); Draganov, D.S. (TU Delft Applied Geophysics and Petrophysics); Weemstra, C. (TU Delft Applied Geophysics and Petrophysics; Royal Netherlands Meteorological Institute (KNMI)); van der Zee, Wouter (Staatstoezicht op de Mijnen); Bakker, R.R. (TU Delft Reservoir Engineering; Staatstoezicht op de Mijnen); Roest, J.C. (Staatstoezicht op de Mijnen)","","2022","We present an overview of induced seismicity due to subsurface engineering in the Netherlands. Our overview includes events induced by gas extraction, underground gas storage, geothermal heat extraction, salt solution mining and post-mining water ingress. Compared to natural seismicity, induced events are usually small (magnitudes ≤ 4.0). However, due to the soft topsoils in combination with shallow hypocentres, in the Netherlands events exceeding magnitude 1.5–2.0 may be felt by the public. These events can potentially damage houses and infrastructure, and undermine public acceptance. Felt events were induced by gas production in the north of the Netherlands and by post-mining water ingress in the south-east. Notorious examples are the earthquakes induced by gas production from the large Groningen gas field with magnitudes up to 3.6. Here, extensive non-structural damage incurred and public support was revoked. As a consequence, production will be terminated in 2022 leaving approximately 800 billion cubic metres of gas unexploited. The magnitudes of the events observed at underground gas storage, geothermal heat production and salt solution mining projects have so far been very limited (magnitudes ≤ 1.7). However, in the future larger events cannot be excluded. Project- or industry-specific risk governance protocols, extensive gathering of subsurface data and adequate seismic monitoring are therefore essential to allow sustainable use of the Dutch subsurface now and over the decades to come.","fault reactivation; Induced seismicity; Netherlands; seismic hazard; subsurface engineering","en","journal article","","","","","","","","","","","Applied Geology","","",""
"uuid:984a94f4-02c2-4441-b948-96b7e0f85850","http://resolver.tudelft.nl/uuid:984a94f4-02c2-4441-b948-96b7e0f85850","The grey – green spectrum: A review of coastal protection interventions","Singhvi, Ankita (Universiteit Leiden); Luijendijk, Arjen (TU Delft Coastal Engineering; Deltares); van Oudenhoven, Alexander P.E. (Universiteit Leiden)","","2022","In the face of uncertainties around coastal management and climate change, coastal engineering interventions need to be able to adapt to changing conditions. Nature-based solutions and other non-traditional, integrated interventions are gaining traction. However, system-based views are not yet embedded into coastal management strategies. Moreover, the differences in coastal interventions, ranging from hard (‘grey’) to nature-based (‘green’) infrastructure remain understudied. In coastal management it is therefore challenging to work with the grey-green spectrum of interventions with clarity and focus, and to produce results that can be evaluated. The objective of this paper was to examine whether there is a common understanding of: the characteristics and differences between grey and green infrastructure, where interventions sit on this spectrum, and the resilience of grey versus green infrastructure. We conducted an integrative literature review of the grey-green spectrum of coastal infrastructure. We examined 105 coastal protection case studies and expanded the double-insurance framework to ensure an integrative approach, looking at both external and internal factors of resilience. Our review showed that external factors are typically used to characterise the grey-green spectrum. However, although useful, they do not facilitate a holistic comparison of alternative interventions. The additional consideration of internal factors (response diversity, multifunctionality, modularity and adaptive, participatory governance) bridges this gap. The review showed that dikes, reefs, saltmarshes, sand nourishment and dunes span a wider segment of the grey-green spectrum than they are generally categorised in. Furthermore, resilient solutions for adaptation are unlikely to be exclusively engineered or natural, but tend to be a mix of the two at different spatial scales (micro, meso, macro and mega). Our review therefore suggests that coastal planners benefit from a more diverse range of options when they consider the incorporation of grey and green interventions in the context of each spatial scale. We propose that internal resilience should be accounted for when infrastructure options are comparatively evaluated. This consideration brings attention to the ways in which the grey-hybrid-green spectrum of infrastructure enhances value for people.","Coastal engineering; Ecological engineering; Ecosystem-based management; Nature-based solutions; Resilience","en","review","","","","","","","","","","","Coastal Engineering","","",""
"uuid:876aa936-ad3f-479b-a30a-0208e67d9894","http://resolver.tudelft.nl/uuid:876aa936-ad3f-479b-a30a-0208e67d9894","A multi-axis robot-based bioprinting system supporting natural cell function preservation and cardiac tissue fabrication","Zhang, Z. (University of Chinese Academy of Sciences; Chinese Academy of Sciences); Wu, Chenming (Tsinghua University); Dai, C. (TU Delft Materials and Manufacturing); Shi, Qingqing (Chinese Academy of Sciences); Fang, G. (TU Delft Materials and Manufacturing; The University of Manchester); Xie, Dongfang (Chinese Academy of Sciences); Zhao, Xiangjie (University of Chinese Academy of Sciences; Chinese Academy of Sciences); Liu, Yong Jin (Tsinghua University); Wang, C.C. (TU Delft Materials and Manufacturing; The University of Manchester); Wang, Xiu Jie (University of Chinese Academy of Sciences; Chinese Academy of Sciences)","","2022","Despite the recent advances in artificial tissue and organ engineering, how to generate large size viable and functional complex organs still remains as a grand challenge for regenerative medicine. Three-dimensional bioprinting has demonstrated its advantages as one of the major methods in fabricating simple tissues, yet it still faces difficulties to generate vasculatures and preserve cell functions in complex organ production. Here, we overcome the limitations of conventional bioprinting systems by converting a six degree-of-freedom robotic arm into a bioprinter, therefore enables cell printing on 3D complex-shaped vascular scaffolds from all directions. We also developed an oil bath-based cell printing method to better preserve cell natural functions after printing. Together with a self-designed bioreactor and a repeated print-and-culture strategy, our bioprinting system is capable to generate vascularized, contractible, and long-term survived cardiac tissues. Such bioprinting strategy mimics the in vivo organ development process and presents a promising solution for in vitro fabrication of complex organs.","3D bioprinting; Artificial organ engineering; Cardiac tissue fabrication; Print-and-culture; Six degree-of-freedom robot","en","journal article","","","","","","","","","","","Materials and Manufacturing","","",""
"uuid:2f6d8981-4194-4dc8-9de7-950e2bb8cb44","http://resolver.tudelft.nl/uuid:2f6d8981-4194-4dc8-9de7-950e2bb8cb44","An embodied conversational agent coach to support societal participation learning by low-literate users","Schouten, D.G.M. (TU Delft Interactive Intelligence); Deneka, Agnes A. (University of Twente); Theune, Mariët (University of Twente); Neerincx, M.A. (TU Delft Interactive Intelligence; TNO); Cremers, Anita H.M. (Hogeschool Utrecht; TNO)","","2022","People of low literacy could benefit from automated support when learning about societal participation. We design an Embodied Conversational Agent (ECA) ‘coach’ that can provide effective learning support to low-literate learners, develop a prototype virtual learning environment, and evaluate this prototype with low-literate end users. First, we inventory the learning support benefits of ECA coaching. Second, we update existing requirements to better specify functional demands for the coach ECA. Third, we write use cases and develop the prototype. Finally, we evaluate the prototype with low-literate users in a mixed-method within-subjects experiment. Results show that the coach influences the subjective learning experience: Participants report higher positive affect, higher user-system engagement, and increased self-efficacy regarding online banking. These results particularly apply to the domain of challenging information skills exercises. Caveats apply: One of four exercises was significantly more difficult than the other three; and coach support rules were not clearly formalized.","Embodied conversational agents; Low literacy; Requirements engineering; Societal participation; Socio-cognitive engineering; Virtual learning environment","en","journal article","","","","","","","","","","","Interactive Intelligence","","",""
"uuid:1541ff0e-a63d-4738-8bf2-7694fdefe400","http://resolver.tudelft.nl/uuid:1541ff0e-a63d-4738-8bf2-7694fdefe400","Effects of adverse sea conditions on propulsion and manoeuvring performance of low-powered ocean-going cargo ship","Sui, Congbiao (TU Delft Ship Design, Production and Operations; Harbin Engineering University); de Vos, P. (TU Delft Ship Design, Production and Operations); Hopman, J.J. (TU Delft Ship Design, Production and Operations); Visser, K. (TU Delft Ship Design, Production and Operations); Stapersma, D. (TU Delft Ship Design, Production and Operations); Ding, Yu (Harbin Engineering University)","","2022","Current EEDI (Energy Efficiency Design Index) regulations striving to reduce the installed engine power on new ships for a low EEDI may lead to underpowered ships having insufficient power when operating in adverse sea conditions. In this paper, the operational safety of a low-powered ocean-going cargo ship operating in adverse sea conditions has been investigated using an integrated ship propulsion, manoeuvring and sea state model. The ship propulsion and manoeuvring performance, especially the dynamic engine behaviour, when the ship is sailing in heavy weather and turning into head sea, have been studied. According to the results, the dynamic engine behaviour should be considered when assessing the ship operational safety, as the static engine operating envelope is inadequate for the safety assessment. The impact of PTO/PTI (power-take-off/in) operation and changing propeller pitch on the ship thrust availability in adverse sea conditions have also been investigated. To protect the engine from mechanical and thermal overloading, compressor surge and over-speeding during dynamic ship operations and/or in high sea states, the engine and propeller should be carefully controlled. The paper shows that if in (heavy) adverse weather the propeller pitch can be reduced or if the shaft generator can work as a motor (PTI), more thrust can be developed which can significantly improve the operational safety of the ship.","Adverse sea; Engine dynamic performance; Low-powered ship; Minimum propulsion power; Ship operational safety","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Ship Design, Production and Operations","","",""
"uuid:dd63f8cc-787a-463d-97a1-4ea56f44021b","http://resolver.tudelft.nl/uuid:dd63f8cc-787a-463d-97a1-4ea56f44021b","Cellular Interaction of Bone Marrow Mesenchymal Stem Cells with Polymer and Hydrogel 3D Microscaffold Templates","Neves Leal Costa, B. (TU Delft Micro and Nano Engineering; International Iberian Nanotechnology Laboratory; University of Minho); Adão, Ricardo M.R. (International Iberian Nanotechnology Laboratory); Maibohm, Christian (International Iberian Nanotechnology Laboratory); Accardo, A. (TU Delft Micro and Nano Engineering); Cardoso, Vanessa F. (University of Minho); Nieder, Jana B. (International Iberian Nanotechnology Laboratory)","","2022","Biomimicking biological niches of healthy tissues or tumors can be achieved by means of artificial microenvironments, where structural and mechanical properties are crucial parameters to promote tissue formation and recreate natural conditions. In this work, three-dimensional (3D) scaffolds based on woodpile structures were fabricated by two-photon polymerization (2PP) of different photosensitive polymers (IP-S and SZ2080) and hydrogels (PEGDA 700) using two different 2PP setups, a commercial one and a customized one. The structures' properties were tuned to study the effect of scaffold dimensions (gap size) and their mechanical properties on the adhesion and proliferation of bone marrow mesenchymal stem cells (BM-MSCs), which can serve as a model for leukemic diseases, among other hematological applications. The woodpile structures feature gap sizes of 25, 50, and 100 μm and a fixed beam diameter of 25 μm, to systematically study the optimal cell colonization that promotes healthy cell growth and potential tissue formation. The characterization of the scaffolds involved scanning electron microscopy and mechanical nanoindenting, while their suitability for supporting cell growth was evaluated with live/dead cell assays and multistaining 3D confocal imaging. In the mechanical assays of the hydrogel material, we observed two different stiffness ranges depending on the indentation depth. Larger gap woodpile structures coated with fibronectin were identified as the most promising scaffolds for 3D BM-MSC cellular models, showing higher proliferation rates. The results indicate that both the design and the employed materials are suitable for further assays, where retaining the BM-MSC stemness and original features is crucial, including studies focused on BM disorders such as leukemia and others. Moreover, the combination of 3D scaffold geometry and materials holds great potential for the investigation of cellular behaviors in a co-culture setting, for example, mesenchymal and hematopoietic stem cells, to be further applied in medical research and pharmacological studies.","bone marrow mesenchymal stem cells; hydrogel; polymer; three-dimensional scaffolds; tissue engineering; two-photon polymerization; woodpile structures","en","journal article","","","","","","","","","","","Micro and Nano Engineering","","",""
"uuid:8808987b-ab5a-4d18-ad1d-efb3ac617baf","http://resolver.tudelft.nl/uuid:8808987b-ab5a-4d18-ad1d-efb3ac617baf","Patient-specific 3D-printed shelf implant for the treatment of hip dysplasia: Anatomical and biomechanical outcomes in a canine model","Willemsen, Koen (University Medical Center Utrecht); Tryfonidou, Marianna (Universiteit Utrecht); Sakkers, Ralph (University Medical Center Utrecht); Castelein, René M. (University Medical Center Utrecht); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Seevinck, Peter (University Medical Center Utrecht); Weinans, Harrie (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht); Meij, Björn (Universiteit Utrecht); van der Wal, Bart C.H. (University Medical Center Utrecht)","","2022","A solution for challenging hip dysplasia surgery could be a patient-specific 3D-printed shelf implant that is positioned extra-articular and restores the dysplastic acetabular rim to normal anatomical dimensions. The anatomical correction and biomechanical stability of this concept were tested in a canine model that, like humans, also suffers from hip dysplasia. Using 3D reconstructed computed tomography images the 3D shelf implant was designed to restore the radiological dysplastic hip parameters to healthy parameters. It was tested ex vivo on three dog cadavers (six hips) with hip dysplasia. Each hip was subjected to a biomechanical subluxation test, first without and then with the 3D shelf implant in place. Subsequently, an implant failure test was performed to test the primary implant fixation. At baseline, the dysplastic hips had an average Norberg angle of 88 ± 3° and acetabular coverage of 47 ± 2% and subluxated at an average of 83 ± 2° of femoral adduction. After adding the patient-specific shelf implants the dysplastic hips had an average Norberg angle of 122 ± 2° and acetabular coverage of 67 ± 3% and subluxated at an average of 117 ± 2° of femoral adduction. Implant failure after primary implant fixation occurred at an average of 1330 ± 320 Newton. This showed that the patient-specific shelf implants significantly improved the coverage and stability of dysplastic hips in a canine model with naturally occurring hip dysplasia. The 3D shelf is a promising concept for treating residual hip dysplasia with a straightforward technology-driven approach; however, the clinical safety needs to be further investigated in an experimental proof-of-concept animal study.","biomechanics; diagnostic imaging; hip; implant fixation; tissue engineering","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:f5ca6212-16ac-42a7-bc99-645f21ea2213","http://resolver.tudelft.nl/uuid:f5ca6212-16ac-42a7-bc99-645f21ea2213","Effect of Impact and Bearing Parameters on Bird Strike with Aero-Engine Fan Blades","Wu, Bin (Tianjin University); Hedayati, R. (TU Delft Novel Aerospace Materials); Li, Zhehua (Tianjin University); Aghajanpour, Mahsa (University of Tehran); Zhang, Guichang (Civil Aviation University of China); Zhang, Junhong (Tianjin University; Tianjin Ren’ai College); Lin, Jiewei (Tianjin University)","","2022","Bird strikes are one major accident for aircraft engines and can inflict heavy casualties and economic losses. In this study, a smoothed particle hydrodynamics (SPH) mallard model has been used to simulate bird impact to rotary aero-engine fan blades. The simulations were performed using the finite element method (FEM) at LS-DYNA. The reliability of the material model and numerical method was verified by comparing the numerical results withWilberk’s experimental results. The effects of impact and bearing parameters, including bird impact location, bird impact orientation, initial bird velocity, fan rotational speeds, stiffness of the bearing, and the damping of the bearing on the bird impact to aero-engine fan blade are studied and discussed. The results show that both the impact location and bird orientation have significant effects on the bird strike results. Bird impact to blade roots is the most dangerous scenario causing the impact force to reach 390 kN. The most dangerous orientation is the case where the bird’s head is tilted 45° horizontally, which leads to huge fan kinetic energy loss as high as 64.73 kJ. The bird’s initial velocity affects blade deformations. The von Mises stress during the bird strike process can reach 1238 MPa for an initial bird velocity of 225 m/s. The fan’s rotational speed and the bearing stiffness affect the rotor stability significantly. The value of bearing damping has little effect on the bird strike process. This paper gives an idea of how to evaluate the strength of fan blades in the design period.","Bearing parameter; Bird strike; Engine fan; Impact parameter; SPH","en","journal article","","","","","","","","","","","Novel Aerospace Materials","","",""
"uuid:af987c16-e31c-4de3-8caf-93c7e90c9c27","http://resolver.tudelft.nl/uuid:af987c16-e31c-4de3-8caf-93c7e90c9c27","Disentangling changes in the river bed profile: The morphological impact of river interventions in a managed river","van Denderen, R. Pepijn (University of Twente; HKV Consultant); Kater, Emiel (Ministry of Infrastructure and the Environment); Jans, Luc H. (Ministry of Infrastructure and the Environment); Schielen, R.M.J. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Ministry of Infrastructure and the Environment)","","2022","The river bed level in low-land rivers like the Rhine branches in The Netherlands changes continuously on various spatial and temporal scales. Large-scale degradation occurs in many rivers due to river-wide engineering interventions, such as channelization, in the last decades and centuries. Local river interventions, such as the construction of side channels, affect the river's morphology by mainly causing sedimentation over the length of the intervention. This sedimentation occurs at a smaller spatial scale than the erosion due to channelization. On an even smaller spatial scale, dune-like bedforms migrate along the river bed but these have a net-zero effect on the morphology. This shows that bed-level changes occur on different spatial scales. Disentangling these spatial scales is appealing from a river management point of view since mitigating large-scale degradation requires a different river management strategy than mitigating erosion and sedimentation due to local interventions. We use detailed bed-level measurements to study the morphological changes on multiple scales using a wavelet transform. A wavelet transform is, unlike a Fourier transform, able to distinguish and disentangle the bed-level changes on different spatial scales while taking into account its spatial variation. Using the wavelet transform, we can disentangle the bed level change caused by a local intervention from the large-scale bed degradation. Both bed level changes are in the same order of magnitude and thereby difficult to determine without filtering. This allows us to study the morphological changes resulting from a single river intervention. The results show that interventions such as side channels cause an average bed-level increase around which the bed level fluctuates. This dynamic component can be up to 6 times larger than the average change. The average bed level increase is in the same order of magnitude as analytical estimations for the equilibrium bed level change. Disentangling spatial scales of bed level changes gives a better understanding of the impact of local interventions and past channelization. These insights can be used to optimize the operation and management of the river and thereby accommodate the main river functions.","Equilibrium; River bed level; River engineering; River interventions; River morphodynamics; Wavelet transform","en","journal article","","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:50fc8792-d93a-4a2a-8b0a-2c65b51ed64f","http://resolver.tudelft.nl/uuid:50fc8792-d93a-4a2a-8b0a-2c65b51ed64f","Monitoring Intracellular Metabolite Dynamics in Saccharomyces cerevisiae during Industrially Relevant Famine Stimuli","Minden, Steven (University of Stuttgart); Aniolek, Maria (University of Stuttgart); Sarkizi Shams Hajian, Christopher (University of Stuttgart); Teleki, Attila (University of Stuttgart); Zerrer, Tobias (University of Stuttgart); Delvigne, Frank (Université de Liège); van Gulik, W.M. (TU Delft BT/Industriele Microbiologie); Deshmukh, Amit (DSM); Noorman, H.J. (TU Delft BT/Bioprocess Engineering; DSM); Takors, Ralf (University of Stuttgart)","","2022","Carbon limitation is a common feeding strategy in bioprocesses to enable an efficient microbiological conversion of a substrate to a product. However, industrial settings inherently promote mixing insufficiencies, creating zones of famine conditions. Cells frequently traveling through such regions repeatedly experience substrate shortages and respond individually but often with a deteriorated production performance. A priori knowledge of the expected strain performance would enable targeted strain, process, and bioreactor engineering for minimizing performance loss. Today, computational fluid dynamics (CFD) coupled to data-driven kinetic models are a promising route for the in silico investigation of the impact of the dynamic environment in the large-scale bioreactor on microbial performance. However, profound wet-lab datasets are needed to cover relevant perturbations on realistic time scales. As a pioneering study, we quantified intracellular metabolome dynamics of Saccharomyces cerevisiae following an industrially relevant famine perturbation. Stimulus-response experiments were operated as chemostats with an intermittent feed and high-frequency sampling. Our results reveal that even mild glucose gradients in the range of 100 µmol·L−1 impose significant perturbations in adapted and non-adapted yeast cells, altering energy and redox homeostasis. Apparently, yeast sacrifices catabolic reduction charges for the sake of anabolic persistence under acute carbon starvation conditions. After repeated exposure to famine conditions, adapted cells show 2.7% increased maintenance demands.","baker’s yeast; bioprocess engineering; bioreactor; chemostat; metabolomics; Saccharomyces cerevisiae; scale-down; scale-up; stimulus-response experiment; substrate gradient; systems biology","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:b508f12b-2c18-47ff-a813-fc135c6694b6","http://resolver.tudelft.nl/uuid:b508f12b-2c18-47ff-a813-fc135c6694b6","The FATE System Iterated: Fair, Transparent and Explainable Decision Making in a Juridical Case","de Boer, Maaike H.T. (TNO); Vethman, Steven (TNO); Bakker, R.M.B. (TNO); Adhikari, Ajaya (TNO); Marcus, Michiel (TNO); de Greeff, Joachim (TNO); van der Waa, J.S. (TU Delft Interactive Intelligence; TNO); van Zoelen, E.M. (TU Delft Interactive Intelligence; TNO); Kamphorst, Bart (TNO)","","2022","The goal of the FATE system is decision support with use of state-of-the-art human-AI co-learning, explainable AI and fair, secure and privacy-preserving usage of data. This AI-based support system is a general system, in which the modules can be tuned to specific use cases. The FATE system is designed to address different user roles, such as a researcher, domain expert/consultant and subject/patient, each with their own requirements. Having examined a Diabetes Type 2 use case before, in this paper we slightly iterate the FATE system and focus on a juridical use case. For a given new juridical case the relevant older court cases are suggested by the system. The relevant older cases can be explained using the eXplainable AI (XAI) module, and the system can be improved based on feedback about the relevant cases using the Co-learning module through interaction with a user. In the Bias module, the use of the system is investigated for potential bias by inspecting the properties of suggested cases. Secure Learning offers privacy-by-design alternatives for functionality found in the aforementioned modules. These results show how the generic FATE system can be implemented in a number of real-world use cases. In future work we plan to explore more use cases within this system.","Bias; Co-Learning; Explainable AI; FAIR AI; Hybrid AI; Knowledge Engineering; Secure Learning","en","journal article","","","","","","","","","","","Interactive Intelligence","","",""
"uuid:6681b504-52f8-459e-9ba5-4bfaeb3a93df","http://resolver.tudelft.nl/uuid:6681b504-52f8-459e-9ba5-4bfaeb3a93df","Evaluation of Proton-Induced DNA Damage in 3D-Engineered Glioblastoma Microenvironments","Akolawala, Q. (TU Delft Micro and Nano Engineering); Rovituso, M. (Holland Particle Therapy Centre); Versteeg, Henri H. (Leiden University Medical Center); Rondon, Araci M.R. (Leiden University Medical Center); Accardo, A. (TU Delft Micro and Nano Engineering)","","2022","Glioblastoma (GBM) is a devastating cancer of the brain with an extremely poor prognosis. For this reason, besides clinical and preclinical studies, novel in vitro models for the assessment of cancer response to drugs and radiation are being developed. In such context, three-dimensional (3D)-engineered cellular microenvironments, compared to unrealistic two-dimensional (2D) monolayer cell culture, provide a model closer to the in vivo configuration. Concerning cancer treatment, while X-ray radiotherapy and chemotherapy remain the current standard, proton beam therapy is an appealing alternative as protons can be efficiently targeted to destroy cancer cells while sparing the surrounding healthy tissue. However, despite the treatment's compelling biological and medical rationale, little is known about the effects of protons on GBM at the cellular level. In this work, we designed novel 3D-engineered scaffolds inspired by the geometry of brain blood vessels, which cover a vital role in the colonization mechanisms of GBM cells. The architectures were fabricated by two-photon polymerization (2PP), cultured with U-251 GBM cells and integrated for the first time in the context of proton radiation experiments to assess their response to treatment. We employed Gamma H2A.X as a fluorescent biomarker to identify the DNA damage induced in the cells by proton beams. The results show a higher DNA double-strand breakage in 2D cell monolayers as compared to cells cultured in 3D. The discrepancy in terms of proton radiation response could indicate a difference in the radioresistance of the GBM cells or in the rate of repair kinetics between 2D cell monolayers and 3D cell networks. Thus, these biomimetic-engineered 3D scaffolds pave the way for the realization of a benchmark tool that can be used to routinely assess the effects of proton therapy on 3D GBM cell networks and other types of cancer cells.","cancer; DNA damage; engineered cell microenvironments; glioblastoma; proton therapy; two-photon polymerization","en","journal article","","","","","","","","","","","Micro and Nano Engineering","","",""
"uuid:32ee8b57-291b-4e36-903e-b3ae762ceb76","http://resolver.tudelft.nl/uuid:32ee8b57-291b-4e36-903e-b3ae762ceb76","Engineering proton-coupled hexose uptake in Saccharomyces cerevisiae for improved ethanol yield","de Valk, S.C. (TU Delft BT/Industriele Microbiologie); Bouwmeester, Susan E. (Student TU Delft); de Hulster, A.F. (TU Delft BT/Industriele Microbiologie); Mans, R. (TU Delft BT/Industriele Microbiologie)","","2022","Background: In the yeast Saccharomyces cerevisiae, which is widely applied for industrial bioethanol production, uptake of hexoses is mediated by transporters with a facilitated diffusion mechanism. In anaerobic cultures, a higher ethanol yield can be achieved when transport of hexoses is proton-coupled, because of the lower net ATP yield of sugar dissimilation. In this study, the facilitated diffusion transport system for hexose sugars of S. cerevisiae was replaced by hexose–proton symport. Results: Introduction of heterologous glucose– or fructose–proton symporters in an hxt0 yeast background strain (derived from CEN.PK2-1C) restored growth on the corresponding sugar under aerobic conditions. After applying an evolutionary engineering strategy to enable anaerobic growth, the hexose–proton symporter-expressing strains were grown in anaerobic, hexose-limited chemostats on synthetic defined medium, which showed that the biomass yield of the resulting strains was decreased by 44.0-47.6%, whereas the ethanol yield had increased by up to 17.2% (from 1.51 to 1.77 mol mol hexose−1) compared to an isogenic strain expressing the hexose uniporter HXT5. To apply this strategy to increase the ethanol yield on sucrose, we constructed a platform strain in which all genes encoding hexose transporters, disaccharide transporters and disaccharide hydrolases were deleted, after which a combination of a glucose–proton symporter, fructose–proton symporter and extracellular invertase (SUC2) were introduced. After evolution, the resulting strain exhibited a 16.6% increased anaerobic ethanol yield (from 1.51 to 1.76 mol mol hexose equivalent−1) and 46.6% decreased biomass yield on sucrose. Conclusions: This study provides a proof-of-concept for the replacement of the endogenous hexose transporters of S. cerevisiae by hexose-proton symport, and the concomitant decrease in ATP yield, to greatly improve the anaerobic yield of ethanol on sugar. Moreover, the sugar-negative platform strain constructed in this study acts as a valuable starting point for future studies on sugar transport or development of cell factories requiring specific sugar transport mechanisms.","Bioethanol; Energy metabolism; Evolutionary engineering; Sugar transport; Yeast physiology","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:4a8e57c9-5516-4165-837f-5f9b3bbe0a38","http://resolver.tudelft.nl/uuid:4a8e57c9-5516-4165-837f-5f9b3bbe0a38","Electrostatically Driven Polarization Flop and Strain-Induced Curvature in Free-Standing Ferroelectric Superlattices","Li, Yaqi (University College London (UCL)); Zatterin, Edoardo (University College London (UCL); European Synchrotron Radiation Facility); Conroy, Michele (Imperial College London; University of Limerick); Pylypets, Anastasiia (Institute of Physics of the Academy of Sciences of the Czech Republic); Borodavka, Fedir (Institute of Physics of the Academy of Sciences of the Czech Republic); Björling, Alexander (MAX IV Laboratory); Groenendijk, D.J. (TU Delft QN/Caviglia Lab; Kavli institute of nanoscience Delft); Lesne, E.L. (TU Delft QN/Steele Lab; Kavli institute of nanoscience Delft); Caviglia, A. (TU Delft QN/Caviglia Lab; Kavli institute of nanoscience Delft)","","2022","The combination of strain and electrostatic engineering in epitaxial heterostructures of ferroelectric oxides offers many possibilities for inducing new phases, complex polar topologies, and enhanced electrical properties. However, the dominant effect of substrate clamping can also limit the electromechanical response and often leaves electrostatics to play a secondary role. Releasing the mechanical constraint imposed by the substrate can not only dramatically alter the balance between elastic and electrostatic forces, enabling them to compete on par with each other, but also activates new mechanical degrees of freedom, such as the macroscopic curvature of the heterostructure. In this work, an electrostatically driven transition from a predominantly out-of-plane polarized to an in-plane polarized state is observed when a PbTiO3/SrTiO3 superlattice with a SrRuO3 bottom electrode is released from its substrate. In turn, this polarization rotation modifies the lattice parameter mismatch between the superlattice and the thin SrRuO3 layer, causing the heterostructure to curl up into microtubes. Through a combination of synchrotron-based scanning X-ray diffraction imaging, Raman scattering, piezoresponse force microscopy, and scanning transmission electron microscopy, the crystalline structure and domain patterns of the curved superlattices are investigated, revealing a strong anisotropy in the domain structure and a complex mechanism for strain accommodation.","ferroelectric domains; free-standing membranes; microtubes; strain engineering","en","journal article","","","","","","","","","","","QN/Caviglia Lab","","",""
"uuid:328eea40-90b3-45c5-9365-98b0ffd8b3b6","http://resolver.tudelft.nl/uuid:328eea40-90b3-45c5-9365-98b0ffd8b3b6","Narrow Pressure Stability Window of Gas Diffusion Electrodes Limits the Scale-Up of CO2Electrolyzers","Baumgartner, L.M. (TU Delft ChemE/Transport Phenomena); Koopman, C.I. (TU Delft ChemE/Transport Phenomena); Forner-Cuenca, Antoni (Eindhoven University of Technology); Vermaas, D.A. (TU Delft ChemE/Transport Phenomena)","","2022","Electrochemical CO2 reduction is a promising process to store intermittent renewable energy in the form of chemical bonds and to meet the demand for hydrocarbon chemicals without relying on fossil fuels. Researchers in the field have used gas diffusion electrodes (GDEs) to supply CO2 to the catalyst layer from the gas phase. This approach allows us to bypass mass transfer limitations imposed by the limited solubility and diffusion of CO2 in the liquid phase at a laboratory scale. However, at a larger scale, pressure differences across the porous gas diffusion layer can occur. This can lead to flooding and electrolyte breakthrough, which can decrease performance. The aim of this study is to understand the effects of the GDE structure on flooding behavior and CO2 reduction performance. We approach the problem by preparing GDEs from commercial substrates with a range of structural parameters (carbon fiber structure, thickness, and cracks). We then determined the liquid breakthrough pressure and measured the Faradaic efficiency for CO at an industrially relevant current density. We found that there is a trade-off between flooding resistance and mass transfer capabilities that limits the maximum GDE height of a flow-by electrolyzer. This trade-off depends strongly on the thickness and the structure of the carbon fiber substrate. We propose a design strategy for a hierarchically structured GDE, which might offer a pathway to an industrial scale by avoiding the trade-off between flooding resistance and CO2 reduction performance.","COreduction; electrochemical engineering; electrochemistry; gas diffusion electrode; scale-up","en","journal article","","","","","","","","","","","ChemE/Transport Phenomena","","",""
"uuid:f59eb904-bdb1-4a59-920b-35d058a6ef18","http://resolver.tudelft.nl/uuid:f59eb904-bdb1-4a59-920b-35d058a6ef18","Solvent Engineering for High-Performance Two-Dimensional Ruddlesden-Popper CsPbI3Solar Cells","Chen, Haiqiang (Lanzhou University); Lei, Yutian (Lanzhou University); Yao, Huanhuan (Lanzhou University); Li, Zhizai (Lanzhou University); Peng, Guoqiang (Lanzhou University); Zhou, Xufeng (Liaocheng University); Wang, H. (TU Delft Photovoltaic Materials and Devices); Wang, Qian (Lanzhou University); Jin, Zhiwen (Lanzhou University)","","2022","Two-dimensional (2D) Ruddlesden-Popper (RP) CsPbI3 exhibits enhanced phase stability compared with 3D CsPbI3. However, the issue of the uncontrollable crystallization process limits its photovoltaic performance. Here, the influence of a binary mixed solvent on the film quality and photovoltaic properties of (PEA)2Cs4Pb5I16 (n = 5) is studied in detail. It is demonstrated that the crystallization rate and crystal growth can be controlled by adjusting the amount of dimethyl sulfoxide (DMSO). Optimizing the solvent composition with adding 10% DMSO in pure dimethyl formamide (DMF) leads to perfect coverage, larger flaky 2D grains, reduced grain boundaries, and a better vertical orientation to the substrate due to the formation of a more stable intermediate phase. This can form good interface contact, which is beneficial to charge transport/extraction between TiO2 (electron transport layer, ETL) and perovskite, finally resulting in improved device performance. The enhancement of the power conversion efficiency of the optimized device based on DMF/DMSO (9:1) is 3.57% compared with the reference device based on pure DMF. This work illustrates the role of crystallization kinetics in the RP CsPbI3 film and offers a simple and effective method for high-performance 2D CsPbI3 solar cells.","2D inorganic perovskites; crystallization kinetics; intermediate phase; Ruddlesden-Popper phase; solvent engineering","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-02-19","","","Photovoltaic Materials and Devices","","",""
"uuid:ccdf1b3d-2aff-4acf-8074-2b80084b8efe","http://resolver.tudelft.nl/uuid:ccdf1b3d-2aff-4acf-8074-2b80084b8efe","An object-oriented geometric engine design for discontinuities in unfitted/immersed/enriched finite element methods","Zhang, J. (TU Delft Computational Design and Mechanics); Zhebel, E.V. (TU Delft Computational Design and Mechanics; EZNumeric); van den Boom, S.J. (TU Delft Computational Design and Mechanics; TNO); Liu, D. (TU Delft Applied Mechanics); Aragon, A.M. (TU Delft Computational Design and Mechanics)","","2022","In this work, an object-oriented geometric engine is proposed to solve problems with discontinuities, for instance, material interfaces and cracks, by means of unfitted, immersed, or enriched finite element methods (FEMs). Both explicit and implicit representations, such as geometric entities and level sets, are introduced to describe configurations of discontinuities. The geometric engine is designed in an object-oriented way and consists of several modules. For efficiency, a (Formula presented.) -d tree data structure that partitions the background mesh is constructed for detecting cut elements whose neighbors are found by means of a dual graph structure. Moreover, the implementation for creating enriched nodes, integration elements, and physical groups is described in detail, and the corresponding pseudo-code is also provided. The complexity and efficiency of the geometric engine are investigated by solving 2-D and 3-D discontinuous models. The capability of the geometric engine is demonstrated on several numerical examples. Topology optimization and problems with intersecting discontinuities are handled with enriched FEMs, where enriched discretizations obtained from the geometric engine are used for the analysis. Furthermore, polycrystalline structures that overlap with an unfitted mesh are considered, where integration elements are created so they align with grain boundaries. Another example shows that the Stanford bunny, which is discretized by a surface mesh with triangular elements, can be fully immersed into a 3-D background mesh. Finally, we share a list of main findings and conclude that the proposed geometric engine is general, robust, and efficient.","discontinuities; enriched finite element methods; geometric engine; level set; mesh generator","en","journal article","","","","","","","","","","","Computational Design and Mechanics","","",""
"uuid:622a406b-6dac-4045-9bc1-a28a95de3f34","http://resolver.tudelft.nl/uuid:622a406b-6dac-4045-9bc1-a28a95de3f34","FABIAN: A daily product of Fractional Austral-summer Blue Ice over ANtarctica during 2000–2021 based on MODIS imagery using Google Earth Engine","Hu, Zhongyang (Universiteit Utrecht); Kuipers Munneke, Peter (Universiteit Utrecht); Lhermitte, S.L.M. (TU Delft Mathematical Geodesy and Positioning); Dirscherl, Mariel (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Ji, Chaonan (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR); Humboldt-Universitat zu Berlin); van den Broeke, Michiel (Universiteit Utrecht)","","2022","Antarctic blue ice areas are exposed due to erosion and sublimation of snow. At the same time, surface melt can form surface types that are spectrally similar to blue ice, especially at low elevations. These are termed melt-induced blue ice areas. Both types of blue ice are sensitive indicators of climate change. Satellite remote sensing is a powerful technique to retrieve the spatial extent of blue ice areas and their variation in time. Yet, existing satellite-derived blue ice area products are either mono-temporal for the entire Antarctic ice sheet, or multi-temporal for a limited area. Here, we present FABIAN, a product of blue ice fraction over Antarctica, derived from the moderate resolution imaging spectroradiometer (MODIS) archive covering the period 2000–2021. A spectral mixture analysis (SMA) in Google Earth Engine, based on a careful selection of endmember spectra, accurately reconstructs the reflectance observed by MODIS in blue ice areas. Based on a validation with contemporaneous Sentinel-2 images, FABIAN has a root mean square error in blue ice fraction of approximately 10% ∼ 20% in wind-induced blue ice areas, and 20% ∼ 30% in melt-induced blue ice areas across six selected test sites in the coastal East Antarctic ice sheet. FABIAN is challenged in regions with shallow melt streams and lakes, since their spectral profiles are similar to those from blue ice areas in MODIS bands. For further analyses and applications, FABIAN holds the potential for (1) deriving annual blue ice area maps, (2) distinguishing between wind-and melt-induced blue ice types, (3) evaluating and correcting (regional) climate models, and (4) analyzing temporal variations in blue ice abundance and exposure.","Antarctica; Blue ice; Google Earth Engine; MODIS; Spectral mixture analysis","en","journal article","","","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:4f3e3b25-ce23-47b3-86a9-5523be3daa1a","http://resolver.tudelft.nl/uuid:4f3e3b25-ce23-47b3-86a9-5523be3daa1a","Carbonation Behavior of Engineered Cementitious Composites under Coupled Sustained Flexural Load and Accelerated Carbonation","Zhang, Hongzhi (Shandong University); Shao, Yingxuan (Shandong University); Zhang, Ning (Shandong Hi-Speed Engineering Test CO); Tawfek, Abdullah M. (Shandong University; Sana'a University); Guan, Yanhua (Shandong University); Sun, Renjuan (Shandong University); Tian, Changjin (Shandong University); Šavija, B. (TU Delft Materials and Environment)","","2022","Engineered cementitious composites (ECCs) belong to a broad class of fibre-reinforced concrete. They incorporate synthetic polyvinyl alcohol (PVA) fibres, cement, fly ash and fine aggregates, and are designed to have a tensile strain capacity typically beyond 3%. This paper presents an investigation on the carbonation behaviour of engineered cementitious composites (ECCs) under coupled sustained flexural load and accelerated carbonation. The carbonation depth under a sustained stress level of 0, 0.075, 0.15, 0.3 and 0.6 relative to flexural strength was measured after 7, 14 and 28 days of accelerated carbonation. Thermogravimetric analysis, mercury intrusion porosimetry and microhardness measurements were carried out to show the coupled influence of sustained flexural load and accelerated carbonation on the changes of the mineral phases, porosity, pore size distribution and microhardness along the carbonation profile. A modified carbonation depth model that can be used to consider the coupled effect of flexural tensile stress and carbonation time was proposed. The results show that an exponential relationship can be observed between stress influence coefficient and flexural tensile stress level in the carbonation depth model of ECC, which is different when using plain concrete. Areas with a higher carbonation degree have greater microhardness, even under a large sustained load level, as the carbonation process refines the pore structure and the fibre bridges the crack effectively.","accelerated carbonation; engineered cementitious composites; microhardness; microstructure; sustained flexural load","en","journal article","","","","","","","","","","","Materials and Environment","","",""
"uuid:a1c4fc01-5e10-46d9-b531-b718070ed63e","http://resolver.tudelft.nl/uuid:a1c4fc01-5e10-46d9-b531-b718070ed63e","BotHunter: An Approach to Detect Software Bots in GitHub","Abdellatif, Ahmad (Concordia University); Wessel, Mairieli (TU Delft Software Engineering); Steinmacher, Igor (Universidade Tecnológica Federal Do Paraná (UTFPR)); Gerosa, Marco A. (Northern Arizona University); Shihab, Emad (Concordia University)","","2022","Bots have become popular in software projects as they play critical roles, from running tests to fixing bugs/vulnerabilities. However, the large number of software bots adds extra effort to practitioners and researchers to distinguish human accounts from bot accounts to avoid bias in data-driven studies. Researchers developed several approaches to identify bots at specific activity levels (issue/pull request or commit), considering a single repository and disregarding features that showed to be effective in other domains. To address this gap, we propose using a machine learning-based approach to identify the bot accounts regardless of their activity level. We selected and extracted 19 features related to the account's profile information, activities, and comment similarity. Then, we evaluated the performance of five machine learning classifiers using a dataset that has more than 5,000 GitHub accounts. Our results show that the Random Forest classifier performs the best, with an F1-score of 92.4% and AUC of 98.7%. Furthermore, the account profile information (e.g., account login) contains the most relevant features to identify the account type. Finally, we compare the performance of our Random Forest classifier to the state-of-the-art approaches, and our results show that our model outperforms the state-of-the-art techniques in identifying the account type regardless of their activity level.","Empirical Software Engineering; Software Bots","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","","","2023-06-01","","","Software Engineering","","",""
"uuid:11a6a2a3-f16a-40a5-a52e-2c2faafed81f","http://resolver.tudelft.nl/uuid:11a6a2a3-f16a-40a5-a52e-2c2faafed81f","Carbon dioxide fixation via production of succinic acid from glycerol in engineered Saccharomyces cerevisiae","Malubhoy, Zahabiya (Jacobs University Bremen); Bahia, Frederico Mendonça (Jacobs University Bremen; Università degli Studi di Milano Bicocca); de Valk, Sophie Claire (Student TU Delft); de Hulster, A.F. (TU Delft BT/Industriele Microbiologie); Rendulić, Toni (Jacobs University Bremen); Ortiz, Juan Paulo Ragas (Jacobs University Bremen); Xiberras, Joeline (Jacobs University Bremen); Klein, Mathias (Jacobs University Bremen); Mans, R. (TU Delft BT/Industriele Microbiologie); Nevoigt, Elke (Jacobs University Bremen)","","2022","Background: The microbial production of succinic acid (SA) from renewable carbon sources via the reverse TCA (rTCA) pathway is a process potentially accompanied by net-fixation of carbon dioxide (CO2). Among reduced carbon sources, glycerol is particularly attractive since it allows a nearly twofold higher CO2-fixation yield compared to sugars. Recently, we described an engineered Saccharomyces cerevisiae strain which allowed SA production in synthetic glycerol medium with a maximum yield of 0.23 Cmol Cmol−1. The results of that previous study suggested that the glyoxylate cycle considerably contributed to SA accumulation in the respective strain. The current study aimed at improving the flux into the rTCA pathway accompanied by a higher CO2-fixation and SA yield. Results: By changing the design of the expression cassettes for the rTCA pathway, overexpressing PYC2, and adding CaCO3 to the batch fermentations, an SA yield on glycerol of 0.63 Cmol Cmol−1 was achieved (i.e. 47.1% of the theoretical maximum). The modifications in this 2nd-generation SA producer improved the maximum biomass-specific glycerol consumption rate by a factor of nearly four compared to the isogenic baseline strain solely equipped with the dihydroxyacetone (DHA) pathway for glycerol catabolism. The data also suggest that the glyoxylate cycle did not contribute to the SA production in the new strain. Cultivation conditions which directly or indirectly increased the concentration of bicarbonate, led to an accumulation of malate in addition to the predominant product SA (ca. 0.1 Cmol Cmol−1 at the time point when SA yield was highest). Off-gas analysis in controlled bioreactors with CO2-enriched gas-phase indicated that CO2 was fixed during the SA production phase. Conclusions: The data strongly suggest that a major part of dicarboxylic acids in our 2nd-generation SA-producer was formed via the rTCA pathway enabling a net fixation of CO2. The greatly increased capacity of the rTCA pathway obviously allowed successful competition with other pathways for the common precursor pyruvate. The overexpression of PYC2 and the increased availability of bicarbonate, the co-substrate for the PYC reaction, further strengthened this capacity. The achievements are encouraging to invest in future efforts establishing a process for SA production from (crude) glycerol and CO2.","Carbon dioxide; CO fixing; Dicarboxylic acids; Fermentation; Glycerol; Metabolic engineering; Saccharomyces cerevisiae; Succinic acid; Yeast","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:314f2613-1196-4e79-bc43-1eafd9d1e829","http://resolver.tudelft.nl/uuid:314f2613-1196-4e79-bc43-1eafd9d1e829","A gastruloid model of the interaction between embryonic and extra-embryonic cell types","Berenger-Currias, N.M.L.P. (TU Delft BN/Timon Idema Lab; Universiteit Leiden; Kavli institute of nanoscience Delft); Mircea, Maria (Universiteit Leiden); Adegeest, Esmée (Universiteit Leiden); van den Berg, Patrick R. (Universiteit Leiden); Feliksik, Marleen (Universiteit Leiden); Hochane, Mazène (Universiteit Leiden); Idema, T. (TU Delft BN/Timon Idema Lab; Kavli institute of nanoscience Delft); Tans, S.J. (TU Delft BN/Sander Tans Lab; Kavli institute of nanoscience Delft; AMOLF); Semrau, Stefan (Universiteit Leiden)","","2022","Stem-cell derived in vitro systems, such as organoids or embryoids, hold great potential for modeling in vivo development. Full control over their initial composition, scalability, and easily measurable dynamics make those systems useful for studying specific developmental processes in isolation. Here we report the formation of gastruloids consisting of mouse embryonic stem cells (mESCs) and extraembryonic endoderm (XEN) cells. These XEN-enhanced gastruloids (XEGs) exhibit the formation of neural epithelia, which are absent in gastruloids derived from mESCs only. By single-cell RNA-seq, imaging, and differentiation experiments, we demonstrate the neural characteristics of the epithelial tissue. We further show that the mESCs induce the differentiation of the XEN cells to a visceral endoderm-like state. Finally, we demonstrate that local inhibition of WNT signaling and production of a basement membrane by the XEN cells underlie the formation of the neuroepithelial tissue. In summary, we establish XEGs to explore heterotypic cellular interactions and their developmental consequences in vitro.","Gastruloids; neuroepithelium; single-cell transcriptomics; stem cell engineering","en","journal article","","","","","","","","","","","BN/Timon Idema Lab","","",""
"uuid:b744923a-1aa8-4826-9e88-220324010e0a","http://resolver.tudelft.nl/uuid:b744923a-1aa8-4826-9e88-220324010e0a","Functionalized Hydrogels for Articular Cartilage Tissue Engineering","Zhou, Liangbin (Chinese University of Hong Kong); Guo, Peng (Chinese University of Hong Kong; AO Research Institute Davos, Davos); D'Este, Matteo (AO Research Institute Davos, Davos); Tong, Wenxue (Chinese University of Hong Kong); Xu, Jiankun (Chinese University of Hong Kong); Yao, Hao (Chinese University of Hong Kong); Stoddart, Martin J. (AO Research Institute Davos, Davos); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Ho, Kevin Ki Wai (Chinese University of Hong Kong); Li, Zhen (AO Research Institute Davos, Davos); Qin, Ling (Chinese Academy of Sciences; Chinese University of Hong Kong)","","2022","Articular cartilage (AC) is an avascular and flexible connective tissue located on the bone surface in the diarthrodial joints. AC defects are common in the knees of young and physically active individuals. Because of the lack of suitable tissue-engineered artificial matrices, current therapies for AC defects, especially full-thickness AC defects and osteochondral interfaces, fail to replace or regenerate damaged cartilage adequately. With rapid research and development advancements in AC tissue engineering (ACTE), functionalized hydrogels have emerged as promising cartilage matrix substitutes because of their favorable biomechanical properties, water content, swelling ability, cytocompatibility, biodegradability, and lubricating behaviors. They can be rationally designed and conveniently tuned to simulate the extracellular matrix of cartilage. This article briefly introduces the composition, structure, and function of AC and its defects, followed by a comprehensive review of the exquisite (bio)design and (bio)fabrication of functionalized hydrogels for AC repair. Finally, we summarize the challenges encountered in functionalized hydrogel-based strategies for ACTE both in vivo and in vitro and the future directions for clinical translation.","Articular cartilage; Cartilage repair; Cartilage tissue engineering; Clinical translation; Functionalized hydrogels","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:beeb7c80-2e86-4ed5-b46d-f205a758d196","http://resolver.tudelft.nl/uuid:beeb7c80-2e86-4ed5-b46d-f205a758d196","Strength formation mechanism and performance of steel slag self-compacting epoxy resin concrete","Li, Yuanyuan (Wuhan Institute of Technology); Li, Jun (Wuhan Institute of Technology); Li, Chao (Foshan Transportation Science and Technology Co.); Chen, Anqi (Wuhan University of Technology); Bai, Tao (Wuhan Institute of Technology); Tang, Shimin (Wuhan Institute of Technology); Wu, Shaopeng (Wuhan University of Technology); Gao, Y. (TU Delft Pavement Engineering); Zhu, Hongbin (Wuhan Institute of Technology); Feng, Jianlin (Wuhan Institute of Technology)","","2022","A self-compacting steel slag epoxy resin concrete (SERC) was designed with steel slag as aggregate and epoxy resin as binder for rapid repair of road expansion joints and pavement. At the same time, a group of self-compacting basalt epoxy resin concrete (BERC) with basalt as coarse aggregate and limestone as fine aggregate was set up as the control group. The element analysis and micro morphology of SERC and BERC were studied by X-ray fluorescence spectrometry (XRF) and scanning electron microscope (SEM) to reveal the strength-forming mechanism of the two epoxy resin concretes. The cube compression test and Marshall stability test were used to study the effect of the strength formation rate and temperature of SERC and BERC on the strength. In addition, the high-temperature stability, low-temperature crack resistance, water damage resistance, fatigue resistance and interlayer bonding properties of SERC and BERC were also studied. The results showed that both SERC and BERC have good mechanical properties, high temperature properties and good bonding properties, and the low-temperature crack resistance and fatigue properties of SERC are better than that of BERC. According to the verification of the actual project that has been in service for one year, SERC can be perfectly used for road expansion joints.","Actual engineering verification; Micro morphology; Pavement repair; Road expansion joints; Steel slag","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Pavement Engineering","","",""
"uuid:3c920283-2db6-4569-b46d-6d9b06c1849c","http://resolver.tudelft.nl/uuid:3c920283-2db6-4569-b46d-6d9b06c1849c","Strain-engineered S-HfSe2 monolayer as a promising gas sensor for detecting NH3: A first-principles study","Yang, Huiru (Harbin Institute of Technology; Southern University of Science and Technology); Li, Junfeng (Southern University of Science and Technology); Shao, Ziyuan (Southern University of Science and Technology); Tan, C. (TU Delft Electronic Components, Technology and Materials); Gao, Chenshan (Southern University of Science and Technology); Cui, Hongyuan (Chongqing University); Tang, Xiaosheng (Chongqing University of Posts and Telecommunications); Liu, Yufei (Chongqing University); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials); Ye, H. (Southern University of Science and Technology; Chongqing University)","","2022","The development of high-performance gas sensing materials is one of the development trends of new gas sensor technology. In this work, in order to predict the gas-sensitive characteristics of HfSe2 and its potential as a gas-sensitive material, the interactions of nonmetallic element (O, S, Te) doped HfSe2 monolayer and small molecules (NH3 and O3) have been studied by first-principles based on density functional theory. The results show that the adsorption of NH3 and O3 on pristine HfSe2 monolayer is weak, and the adsorption strength can be significantly improved by doping O. And O-HfSe2 is chemical adsorption to O3 with large adsorption energy and transfer charge, and the band gap of O[sbnd]HfSe2 disappears after adsorbing O3, indicating that the adsorption of O3 has a significant effect on the electrical properties of the substrate. These mean that O3 is difficult to recover from the substrate surface, thus preventing O-HfSe2 from developing into a sensitive material for O3 detection. After doping S, the charge transfers and adsorption strength to NH3 are the largest, but it is still small. So, the strain effect on the S-HfSe2/NH3 adsorption system is also studied. The results indicate that the adsorption strength of S-HfSe2 to NH3 can be enhanced by stretching S-HfSe2 along x-axis. After absorbing NH3, the conductivity of x-axis strained S-HfSe2 changes, which suggest its sensitivity. And the predicted recovery times of S-HfSe2 surfaces with εx=4%, 6% and 8% are 0.027 s, 1.153 s and 102.467 s, respectively, which suggests that the S-HfSe2 monolayer has the potential to be developed as a sensitive material for NH3 detection. These adsorption mechanism studies can also serve as a theoretical foundation for the experimental design of gas-sensing materials.","Adsorption; Doped HfSe; First-principles; NH; Strain engineering","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Electronic Components, Technology and Materials","","",""
"uuid:cef1df36-ab8f-4385-a8f0-80d72911700b","http://resolver.tudelft.nl/uuid:cef1df36-ab8f-4385-a8f0-80d72911700b","Enzyme Engineering Enables Inversion of Substrate Stereopreference of the Halogenase WelO5*","Voss, Moritz (Zurich University of Applied Science (ZHAW)); Hüppi, S.N. (TU Delft BT/Biocatalysis; Zurich University of Applied Science (ZHAW)); Schaub, Daniela (Zurich University of Applied Science (ZHAW)); Hayashi, Takahiro (Zurich University of Applied Science (ZHAW); Mitsubishi Chemical Corporation, Yokohama); Ligibel, Mathieu (Novartis Pharma); Sager, Emine (Novartis Pharma); Schroer, Kirsten (Novartis Pharma); Snajdrova, Radka (Novartis Pharma); Buller, Rebecca (Zurich University of Applied Science (ZHAW))","","2022","Enzymatic late-stage diversification of small molecules has the potential to rapidly generate diversity in compound libraries dedicated to drug discovery. In this context, freestanding Fe(II)/α-ketoglutarate-dependent halogenases have raised particular interest as this enzyme family allows the otherwise difficult regio- and stereoselective halogenation of unactivated C(sp3)−H bonds. Here, we report the development of two engineered variants of the halogenase WelO5* for the racemic resolution of a mixture of stereoisomers generated in the synthesis of a bioactive martinelline-derived fragment. By screening a 3-site combinatorial variant library, we could identify two variants exhibiting exquisite substrate selectivity towards the desired enantiomers. Strikingly, the inversion of substrate stereopreference between the halogenase variants was achieved by varying only three residues in the active site. Protein crystallization and subsequent structure elucidation of the wildtype enzyme and a WelO5* variant shed light on the factors governing substrate acceptance and selectivity.","biocatalysis; halogenase; kinetic resolution; protein crystallography; protein engineering","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:85994994-df8d-4d29-aa60-b06213481d81","http://resolver.tudelft.nl/uuid:85994994-df8d-4d29-aa60-b06213481d81","Swelling-Dependent Shape-Based Transformation of a Human Mesenchymal Stromal Cells-Laden 4D Bioprinted Construct for Cartilage Tissue Engineering","Diaz Payno, P.J. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Kalogeropoulou, Maria (Student TU Delft); Muntz, I.A.A. (TU Delft BN/Gijsje Koenderink Lab; Kavli institute of nanoscience Delft); Kingma, Esther (Student TU Delft); Kops, Nicole (Erasmus MC); D'Este, Matteo (AO Research Institute Davos, Davos); Koenderink, G.H. (TU Delft BN/Gijsje Koenderink Lab; Kavli institute of nanoscience Delft); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","3D bioprinting is usually implemented on flat surfaces, posing serious limitations in the fabrication of multilayered curved constructs. 4D bioprinting, combining 3D bioprinting with time-dependent stimuli-induced transformation, enables the fabrication of shape-changing constructs. Here, a 4D biofabrication method is reported for cartilage engineering based on the differential swelling of a smart multi-material system made from two hydrogel-based materials: hyaluronan and alginate. Two ink formulations are used: tyramine-functionalized hyaluronan (HAT, high-swelling) and alginate with HAT (AHAT, low-swelling). Both inks have similar elastic, shear-thinning, and printability behavior. The inks are 3D printed into a bilayered scaffold before triggering the shape-change by using liquid immersion as stimulus. In time (4D), the differential swelling between the two zones leads to the scaffold's self-bending. Different designs are made to tune the radius of curvature and shape. A bioprinted formulation of AHAT and human bone marrow cells demonstrates high cell viability. After 28 days in chondrogenic medium, the curvature is clearly present while cartilage-like matrix production is visible on histology. A proof-of-concept of the recently emerged technology of 4D bioprinting with a specific application for the design of curved structures potentially mimicking the curvature and multilayer cellular nature of native cartilage is demonstrated.","4D bioprinting; biofabrication; shape-change; smart bioinks; tissue engineering","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:99dc4a89-524a-4740-95f0-bf3af94012a9","http://resolver.tudelft.nl/uuid:99dc4a89-524a-4740-95f0-bf3af94012a9","An Interface Co-modification Strategy for Improving the Efficiency and Stability of CsPbI3Perovskite Solar Cells","Guan, Hui (Lanzhou University); Lei, Yutian (Lanzhou University); Wu, Qiyuan (Lanzhou University); Zhou, Xufeng (Liaocheng University); Wang, H. (TU Delft Photovoltaic Materials and Devices); Wang, Gang (Ningbo University); Li, Wenquan (Qinghai Normal University); Jin, Zhiwen (Lanzhou University); Lan, Wei (Lanzhou University)","","2022","Interface engineering is a simple and effective strategy for improving the photovoltaic performance and stability of perovskite solar cells (PSCs). Herein, an interface co-modification strategy is proposed, using [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and 2-fluoro-1,4-phenylenediammonium iodide (2FPPD) to modify the electron transport layer (ETL)/perovskite (PVK) and the PVK/hole transport layer (HTL) interfaces, respectively. A series of characterizations demonstrate that the PCBM&2FPPD interface co-modification strategy effectively enhances the extraction and transport efficiency of carriers at the interface, passivates surface defects, inhibits the nonradiative recombination of carriers, and simultaneously inhibits ion migration. Moreover, this strategy improves the crystallinity and surface hydrophobicity of PVK and optimizes the energy level alignment of PSCs. As a result, all photovoltaic parameters are improved after optimization, where the power conversion efficiency (PCE) of PSCs has increased from 17.01% to 18.36%. Meanwhile, the optimized PSCs show excellent environmental stability, which can be stably stored in air (RH = 10-20%) for about 800 h.","CsPbI; defect passivation; interface engineering; perovskite solar cell; photovoltaic performance; stability","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-04-27","","","Photovoltaic Materials and Devices","","",""
"uuid:f94bed19-590e-472a-b54f-4c6f668272c5","http://resolver.tudelft.nl/uuid:f94bed19-590e-472a-b54f-4c6f668272c5","An engineered non-oxidative glycolytic bypass based on Calvin-cycle enzymes enables anaerobic co-fermentation of glucose and sorbitol by Saccharomyces cerevisiae","van Aalst, A.C.A. (TU Delft BT/Industriele Microbiologie); Mans, R. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie)","","2022","Background: Saccharomyces cerevisiae is intensively used for industrial ethanol production. Its native fermentation pathway enables a maximum product yield of 2 mol of ethanol per mole of glucose. Based on conservation laws, supply of additional electrons could support even higher ethanol yields. However, this option is disallowed by the configuration of the native yeast metabolic network. To explore metabolic engineering strategies for eliminating this constraint, we studied alcoholic fermentation of sorbitol. Sorbitol cannot be fermented anaerobically by S. cerevisiae because its oxidation to pyruvate via glycolysis yields one more NADH than conversion of glucose. To enable re-oxidation of this additional NADH by alcoholic fermentation, sorbitol metabolism was studied in S. cerevisiae strains that functionally express heterologous genes for ribulose-1,5-bisphosphate carboxylase (RuBisCO) and phosphoribulokinase (PRK). Together with the yeast non-oxidative pentose-phosphate pathway, these Calvin-cycle enzymes enable a bypass of the oxidative reaction in yeast glycolysis. Results: Consistent with earlier reports, overproduction of the native sorbitol transporter Hxt15 and the NAD+-dependent sorbitol dehydrogenase Sor2 enabled aerobic, but not anaerobic growth of S. cerevisiae on sorbitol. In anaerobic, slow-growing chemostat cultures on glucose–sorbitol mixtures, functional expression of PRK-RuBisCO pathway genes enabled a 12-fold higher rate of sorbitol co-consumption than observed in a sorbitol-consuming reference strain. Consistent with the high Km for CO2 of the bacterial RuBisCO that was introduced in the engineered yeast strains, sorbitol consumption and increased ethanol formation depended on enrichment of the inlet gas with CO2. Prolonged chemostat cultivation on glucose–sorbitol mixtures led to loss of sorbitol co-fermentation. Whole-genome resequencing after prolonged cultivation suggested a trade-off between glucose-utilization and efficient fermentation of sorbitol via the PRK-RuBisCO pathway. Conclusions: Combination of the native sorbitol assimilation pathway of S. cerevisiae and an engineered PRK-RuBisCO pathway enabled RuBisCO-dependent, anaerobic co-fermentation of sorbitol and glucose. This study demonstrates the potential for increasing the flexibility of redox-cofactor metabolism in anaerobic S. cerevisiae cultures and, thereby, to extend substrate range and improve product yields in anaerobic yeast-based processes by enabling entry of additional electrons.","CO; Electrons; Ethanol; Fermentation; NADH; Redox engineering; Sorbitol; Yeast","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:17d38de3-f375-4fa5-b493-60e64e594480","http://resolver.tudelft.nl/uuid:17d38de3-f375-4fa5-b493-60e64e594480","Towards a multi-faceted framework for planning and evaluating innovation in Engineering Education","Engelbrecht, E. (TU Delft Teaching & Learning Services; TU Delft Spatial Planning and Strategy); Rooij, R.M. (TU Delft Spatial Planning and Strategy); Specht, M.M. (TU Delft Web Information Systems)","","2022","For universities, educational change at institutional level is a slow process [1], [2]. To keep up with societal and technological advancement, education innovation project leaders at universities need practical guidelines and procedures in place that will enable sustainable and scalable innovation that can meet the needs of industry as we transition from Industry 4.0 to Industry 5.0 [3]. To develop such guidelines and procedures, we need to conduct socially responsible, evidence-based educational research [4]. This paper is part of a larger study during which we will conceptualize the planning and evaluation of innovation in engineering education at the Delft University of Technology (TU Delft). From this conceptualization, a framework for planning and evaluation of education innovation will emerge. The data collection process will take place in six phases: (1) Exploration of the problem (2) feasibility studies; (3) conceptualization and development of the framework; (4) piloting of the framework and its associated processes; (5) field study; and lastly, (6) evaluation of the framework. This paper provides an initial overview of the literature, as well as an explanation of the proposed research methodology.","concept mapping; engineering education; Higher Education; Innovation; research methodology","en","journal article","","","","","","","","","","","Teaching & Learning Services","","",""
"uuid:e645b25f-716a-4fa2-8b91-6803ac781d0f","http://resolver.tudelft.nl/uuid:e645b25f-716a-4fa2-8b91-6803ac781d0f","Graph machine learning for design of high-octane fuels","Rittig, J. (Rheinisch-Westfälische Technische Hochschule); Ritzert, Martin (Aarhus University); Schweidtmann, A.M. (TU Delft ChemE/Product and Process Engineering); Winkler, Stefanie (Rheinisch-Westfälische Technische Hochschule); Weber, J.M. (TU Delft Pattern Recognition and Bioinformatics); Morsch, Philipp (Rheinisch-Westfälische Technische Hochschule); Heufer, Karl Alexander (Rheinisch-Westfälische Technische Hochschule); Grohe, Martin (Rheinisch-Westfälische Technische Hochschule); Mitsos, Alexander (Rheinisch-Westfälische Technische Hochschule; Forschungszentrum Jülich GmbH); Dahmen, Manuel (Forschungszentrum Jülich GmbH)","","2022","Fuels with high-knock resistance enable modern spark-ignition engines to achieve high efficiency and thus low CO2 emissions. Identification of molecules with desired autoignition properties indicated by a high research octane number and a high octane sensitivity is therefore of great practical relevance and can be supported by computer-aided molecular design (CAMD). Recent developments in the field of graph machine learning (graph-ML) provide novel, promising tools for CAMD. We propose a modular graph-ML CAMD framework that integrates generative graph-ML models with graph neural networks and optimization, enabling the design of molecules with desired ignition properties in a continuous molecular space. In particular, we explore the potential of Bayesian optimization and genetic algorithms in combination with generative graph-ML models. The graph-ML CAMD framework successfully identifies well-established high-octane components. It also suggests new candidates, one of which we experimentally investigate and use to illustrate the need for further autoignition training data.","computer-aided molecular design; fuel design; graph machine learning; graph neural networks; machine learning; optimization; renewable fuels; spark-ignition engines","en","journal article","","","","","","","","","","","ChemE/Product and Process Engineering","","",""
"uuid:ba7462dd-7541-452e-b809-59a31776dea1","http://resolver.tudelft.nl/uuid:ba7462dd-7541-452e-b809-59a31776dea1","When Flooding Is Not Catastrophic Woven Gas Diffusion Electrodes Enable Stable CO2Electrolysis","Baumgartner, L.M. (TU Delft ChemE/Transport Phenomena); Koopman, C.I. (TU Delft ChemE/Transport Phenomena); Forner-Cuenca, Antoni (Eindhoven University of Technology); Vermaas, D.A. (TU Delft ChemE/Transport Phenomena)","","2022","Electrochemical CO2 reduction has the potential to use excess renewable electricity to produce hydrocarbon chemicals and fuels. Gas diffusion electrodes (GDEs) allow overcoming the limitations of CO2 mass transfer but are sensitive to flooding from (hydrostatic) pressure differences, which inhibits upscaling. We investigate the effect of the flooding behavior on the CO2 reduction performance. Our study includes six commercial gas diffusion layer materials with different microstructures (carbon cloth and carbon paper) and thicknesses coated with a Ag catalyst and exposed to differential pressures corresponding to different flow regimes (gas breakthrough, flow-by, and liquid breakthrough). We show that physical electrowetting further limits the flow-by regime at commercially relevant current densities (≥200 mA cm-2), which reduces the Faradaic efficiency for CO (FECO) for most carbon papers. However, the carbon cloth GDE maintains its high CO2 reduction performance despite being flooded with the electrolyte due to its bimodal pore structure. Exposed to pressure differences equivalent to 100 cm height, the carbon cloth is able to sustain an average FECO of 69% at 200 mA cm-2 even when the liquid continuously breaks through. CO2 electrolyzers with carbon cloth GDEs are therefore promising for scale-up because they enable high CO2 reduction efficiency while tolerating a broad range of flow regimes.","COreduction; electrochemical engineering; electrochemistry; gas diffusion electrode; scale-up","en","journal article","","","","","","","","","","","ChemE/Transport Phenomena","","",""
"uuid:1ae9c61a-8825-4f19-aeb3-5a9bf3939ffe","http://resolver.tudelft.nl/uuid:1ae9c61a-8825-4f19-aeb3-5a9bf3939ffe","Analyzing and Controlling Construction Engineering Project Gray Rhino Risks with Innovative MCDM Methods: Interference Fuzzy Analytical Network Process and Decision-Making Trial and Evaluation Laboratory","Guo, Jeen (Chongqing University); Xiang, Pengcheng (Chongqing University); Li, Y. (TU Delft Design & Construction Management)","","2022","Construction engineering projects are costly and require large amounts of labor, physical, and financial resources. The failure of a construction engineering project typically brings huge losses. Previous studies have focused on the identification of risks, but insufficient attention has been given to strategic resource allocation for risk management after risk identification. Statistics show that most construction engineering project failures are caused by common risks. Common risks are called gray rhino risks. This metaphor illustrates that many risks are obvious but dangerous. This study was motivated by the challenge of efficiently managing gray rhino risks with limited inputs. The literature suggests that gray rhino risks are abundant in construction engineering projects and that there are mutual eliciting relationships between them, which make it difficult for the manager to devote enough resources to the prevention of key risks. Considerable resources are wasted on unimportant risks, resulting in key risk occurrence and failure of construction engineering projects. Therefore, this study describes an innovative multi-criteria decision making (MCDM) technique for ranking risks based on the strength of the eliciting relationships between them. This study used the fuzzy technique and created an interference fuzzy analytical network process (IF-ANP) method. By employing the IF-ANP alongside a decision-making trial and evaluation laboratory (DEMATEL) approach, the subjectivity can be effectively reduced and the accuracy improved during expert risk evaluation for construction engineering projects. IF-ANP was used to quantify eliciting relationships between risks and DEMATEL was used to rank risks based on the IF-ANP result. An empirical study was done to meticulously rank five risks that were selected from the gray rhino risks in the Chengdu–Chongqing Middle Line High-speed Railway construction engineering project. They are capital chain rupture, decision failure, policy and legal risk, economic downturn, and stakeholder conflict. The results showed that the policy and legal risk was the source of other risks, and that these other risks were symptoms rather than the disease.","MCDM; IF-ANP and DEMATEL; gray rhino risks; construction engineering project","en","journal article","","","","","","","","","","","Design & Construction Management","","",""
"uuid:087ee728-f3ed-43a4-81f2-e99c5ca542bd","http://resolver.tudelft.nl/uuid:087ee728-f3ed-43a4-81f2-e99c5ca542bd","A processing chain for estimating crop biophysical parameters using temporal Sentinel-1 synthetic aperture radar data in cloud computing framework","Mandal, Dipankar (Indian Institute of Technology Bombay; Kansas State University); Kumar, V. (TU Delft Mathematical Geodesy and Positioning); Lopez-Sanchez, Juan M. (Universitat d'Alacant); Rao, Y. S. (Indian Institute of Technology Bombay); McNairn, Heather (Ottawa Research and Development Centre); Bhattacharya, Avik (Indian Institute of Technology Bombay); Mitchell, Scott (Carleton University)","","2022","Biophysical parameters are descriptors of crop growth and production estimates. Retrieval of these biophysical parameters from synthetic aperture radar sensors at operational scales is highly interesting given the increase in access to data from radar missions. Vegetation backscattering can be simulated using the water cloud model (WCM). Crop biophysical parameters are obtained by inverting this model. However, the inversion problem is ill-posed, and existing methods, which include the lookup table (LUT) and iterative search algorithms, are often computationally intensive and lack good generalization capacity. This might make retrieval of the biophysical parameters computationally intensive for large study areas. In addition, the new generation of operational missions, which are often associated with a large volume of data, poses a challenge for estimating crop parameters. In this work, we use the cloud computing potentials of the Google Earth Engine (GEE) to demonstrate a unified processing pipeline for WCM inversion. The processing pipeline (GEE4Bio) uses Sentinel-1 radar measurements for WCM inversion and subsequently produces crop biophysical maps. Inversion is achieved by employing Random Forest regression, which is trained with radar backscatter measurements at Vertical transmit and vertical receive (VV) and Vertical transmit and horizontal receive (VH) channels. The model is trained and validated with independent calibration and validation datasets consisting of ground measurements for five major crops over the Joint Experiment for Crop Assessment and Monitoring–Carman test site in Canada. The inversion accuracies indicate strong correlation coefficients (r) of 0.83 and 0.87, with the estimated and in situ measured plant area index and wet biomass, respectively, with low root mean square error values. The GEE4Bio processing chain produced crop inventory maps with a reasonable time and apprehended the variability in plant growth across the test site.","Cloud computing; Crop; Google Earth Engine; Model inversion; PAI; Sentinel-1","en","book chapter","Elsevier","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Mathematical Geodesy and Positioning","","",""
"uuid:a60de7d8-f9af-48e8-bd07-2e302bf86517","http://resolver.tudelft.nl/uuid:a60de7d8-f9af-48e8-bd07-2e302bf86517","Framework of visualising and analysing urban transformation features responding to Covid 19 pandemic","Chu, L. (TU Delft Web Information Systems); Nelen, Jeroen (Student TU Delft); Höller, L. (TU Delft Spatial Planning and Strategy); Lasch, Hülya (HafenCity University Hamburg); Schubert, Dirk (HafenCity University Hamburg); Hein, C.M. (TU Delft History, Form & Aesthetics); Lofi, C. (TU Delft Web Information Systems)","","2022","Long-term exposure to ambient air pollution is one of the main public health concerns worldwide. Exposure to air pollution is highly related to a range of diseases including respiratory and cardiovascular diseases, such as lung cancers, asthma, diabetes, irregular heartbeat, stroke and obesity [1-3]. The outbreak of the pathogenic agent of coronavirus disease 19 (Covid-19) has led to a large number of deaths worldwide, and previous studies have pointed out how the long-term exposure to air pollution may have an impact on its high death rate [4]. Moreover, the hospitalization rate and infected population numbers are central indicators for lock-down policy-making, indicating whether the local medical system is able to handle the increasing infected population number through its available intensive care facilities. In fact, predicting hospitalization is vital for authorities and policymakers. We hereby hypothesize that high air pollutants concentration leads to a rise in the hospitalization rate under the influence of Covid-19 outbreaks. We attempt to predict such hospitalization numbers for past data by means of a task-specific optimized machine learning model, after we integrate social, economic, cultural, and other environmental features in future with an ongoing project we are conducting. While such a prediction model cannot directly be used for predicting the future development of the pandemic, analysing it still gives valuable insights on the influence of various environmental features had on it in the past.Air pollution is a mixture of a large number of chemical compounds such as CO2, CO, NOx, SO2, O3, heavy metals, and respirable particulate matter (PM2.5 and PM10); the main sources of such pollutants are identified as vehicle traffic, heating systems, and industrial plants [5]. Previous studies focused on the relationships between the variables of pandemic with the air pollutants information. Among all the air pollutants, NO2 and respirable articulate matter are highly related to the pandemic variables [6-8]. In our research, we extract the air pollutants information (CO, NO2, CH4, SO2) from the Sentinel-5P TROPOMI sensor, and integrate it with open-access data on Covid-19 features (mortality, infection rate, intensive care rate, etc). The air pollutant data is processed from the Sentinel-5P data catalog provided in Google Earth Engine. We therefore aim to ascertain the relationships between hospitalization and air pollutants concentration with the incidence of Covid-19. In particular, our ultimate research purpose is to develop a machine learning model to uncover the relationships between a mixture of features derived from air pollutants and Covid-19 related information, at municipality scales in Germany and the Netherlands. The relationships provide important clues on understanding how air pollution may affect on hospitalization rate and other features of Covid-19, through the evidence of potential low hospitalization or low mortality with better air quality. The output will deliver key information regarding public health effects and control of emission in Germany and the Netherlands.
Specifically, on a temporal scale, we aggregated daily Covid-19 data and four air pollutant measures into weekly measures. On a spatial scale, the air pollutants were aggregated based on each municipality in Germany and the Netherlands to match the Covid-19 features. A choice of machine learning models were trained and evaluated on historical data (from March of 2020 to Oct of 2021), using features comprising weekly hospitalizations, death rate, and infected rate, tropospheric NO2 concentration, CO, SO2, CH4 concentrations. In addition, a post-processing analysis using machine-learning explainability methodologies was carried out to mine potential relationships between hospitalization attributes and specific air pollution concentration features. By processing municipalities as separate spatial entities, the results are intended to highlight hospitalization disparities and pollutants’ effect diversities among different geographic areas.
By highlighting the relationships between air pollutant concentrations and incidence of Covid-19 with the hospitalization rate, and illustrating the hospitalization disparities among municipalities, our results provide key information regarding policymaking on urban emission control and public health at municipality level. When integrating other Covid-related features, our models could offer support to policymakers on effective lock-down decisions and health system management.
Keywords: Air pollutant, Covid-19, supervised machine learning models, Google Earth Engine.
Reference
1. Bernstein, J.A., et al., Health effects of air pollution. Journal of allergy and clinical immunology, 2004. 114(5): p. 1116-1123.
2. Brunekreef, B. and S.T. Holgate, Air pollution and health. The lancet, 2002. 360(9341): p. 1233-1242.
3. Strak, M., et al., Long-term exposure to particulate matter, NO2 and the oxidative potential of particulates and diabetes prevalence in a large national health survey. Environment international, 2017. 108: p. 228-236.
4. Ogen, Y., Assessing nitrogen dioxide (NO2) levels as a contributing factor to coronavirus (COVID-19) fatality. Science of The Total Environment, 2020. 726: p. 138605.
5. Vineis, P., et al., Air pollution and risk of lung cancer in a prospective study in Europe. International Journal of Cancer, 2006. 119(1): p. 169-174.
6. Gautam, S., COVID-19: air pollution remains low as people stay at home. Air Quality, Atmosphere & Health, 2020. 13: p. 853-857.
7. Vîrghileanu, M., et al., Nitrogen Dioxide (NO2) Pollution monitoring with Sentinel-5P satellite imagery over Europe during the coronavirus pandemic outbreak. Remote Sensing, 2020. 12(21): p. 3575.
8. Omrani, H., et al., Spatio-temporal data on the air pollutant nitrogen dioxide derived from Sentinel satellite for France. Data in Brief, 2020. 28: p. 105089.","Air pollutant; Covid-19; supervised machine learning models; Google Earth Engine (GEE)","en","poster","","","","","","","","","","","Web Information Systems","","",""
"uuid:002fd175-87bf-4f59-9428-96c0a3d3f6f8","http://resolver.tudelft.nl/uuid:002fd175-87bf-4f59-9428-96c0a3d3f6f8","Droplet microfluidics for bioprocess engineering","Totlani, K. (TU Delft ChemE/Product and Process Engineering)","van Steijn, V. (promotor); van Gulik, W.M. (promotor); Kreutzer, M.T. (promotor); Delft University of Technology (degree granting institution)","2021","A crucial challenge during the initial stages of bioprocess development is that tools used to screen microorganisms and optimize cultivation conditions do not represent the environment imposed at industrial scale. Inside an industrial-scale bioreactor, microorganisms are often cultivated under fed-batch conditions, where nutrients are supplied during the culture. Additionally, microorganisms continuously keep crossing zones with low and high concentrations of substrate and dissolved oxygen. However, during initial bioprocess development, growth and productivity of microorganisms are evaluated under batch conditions due to the difficulty of dynamically controlling nutrient and dissolved oxygen concentrations in screening equipment such as micotiter plates. This inconsistency in cultivation conditions often leads to selection of strains that fail to perform at industrial scale. The difficulty in continuously supplying minute amounts of nutrients to microorganisms in microtiter plates and imposing dynamic dissolved oxygen levels throughout the cultivation experiment necessitates an alternative approach. Microfluidic technology holds the potential to address this inconsistency with fidelity by offering high-throughput experimentation and excellent control over the culture microenvironment. The central theme of this Ph.D. project is the design and development of droplet-based microfluidic technology, that enable studying microorganisms under such dynamically controlled cultivation conditions. As such, the outcomes from this Ph.D. project form a foundation step towards narrowing the gap between screening and industrial-scale use, with an eye to keeping the technology sufficiently simple to be adopted by the biotechnology and bioengineering community.","Bioprocess engineering; droplet microfluidics; droplet on-demand; fed-batch; nutrient-controlled growth; yeast; dissolved oxygen; droplet-based assays; lab-on-a-chip","en","doctoral thesis","","978-94-6421-522-9","","","","","","","","","ChemE/Product and Process Engineering","","",""
"uuid:db85753a-8d32-4a0b-b220-780fed198672","http://resolver.tudelft.nl/uuid:db85753a-8d32-4a0b-b220-780fed198672","Parameter estimation in single molecule microscopy","Thorsen, R.Ø. (TU Delft ImPhys/Computational Imaging)","Rieger, B. (promotor); Stallinga, S. (promotor); Delft University of Technology (degree granting institution)","2021","","photometry; aberrations; structured illumination; dipole emitters; point-spread-function engineering; polarization","en","doctoral thesis","","","","","","","","","","","ImPhys/Computational Imaging","","",""
"uuid:2f965fc6-c8df-4f4c-af20-702067901c91","http://resolver.tudelft.nl/uuid:2f965fc6-c8df-4f4c-af20-702067901c91","Energy Effectiveness and Operational Safety of Low-Powered Ocean-going Cargo Ship in Various (Heavy) Operating Conditions","Sui, Congbiao (TU Delft Ship Design, Production and Operations)","Hopman, J.J. (promotor); de Vos, P. (copromotor); Delft University of Technology (degree granting institution)","2021","The shipping industry, which remains the backbone of international merchandise trade, is striving to reduce its operational cost and more importantly its environment impact. New ships need meet the EEDI (Energy Efficiency Design Index) requirements of IMO (International Maritime Organization). However, the current EEDI is not able to accurately evaluate the real lifetime carbon emissions of the ship. Under the guidance of current EEDI regulation, the ship designers, owners and policymakers could be misled to adopt the configurations that are underperforming or even leading to an increase of CO2 emissions in reality. A technically easy and effective solution to meet the EEDI requirement is to lower the installed engine power and thus the ship design speed. However, reducing the installed engine power could lead to an underpowered ship, which could have insufficient power for propulsion and steering in adverse weather conditions.
The main research question addressed in this dissertation is:
What is the transport performance of ocean-going cargo ships with small EEDI when sailing in realistic operating conditions; are these ships safe when sailing in heavy operating conditions; and, how to improve both the transport performance and operational safety of ocean-going cargo ships by using the short-term applicable ship propulsion options?
The ship transport performance investigated in this dissertation includes the energy conversion performance, fuel consumption performance and emissions performance. The influences of the operational ship speed reduction, propulsion control, PTO (power-take-off)/PTI (power-take-in), and using LNG (liquefied natural gas) as the fuel as well as the combination of these measures on the ship transport performance have been systematically investigated.
The operational safety investigated in this dissertation includes both engine operational safety and ship operational safety. The engine dynamic behaviour during ship acceleration, deceleration, crash stop, and turning in normal sea condition have been investigated. The ship propulsion and manoeuvring performance when sailing in head sea, accelerating in head sea and turning to head sea in adverse sea conditions have been investigated. The influences of propeller pitch and PTO/PTI on the ship thrust limit and engine behaviour have also been investigated.
As a reflection of the research in this dissertation, suggestions on amendments of IMO’s current EEDI has been provided. The proposal for amending the current EEDI formula tries to make the EEDI calculation more realistic and representative when evaluating ship transport performance at the design stage. Moreover, it can also partly solve the other weakness of the current EEDI with respect to the issues of underpowered ships.","Ship propulsion system; hybrid propulsion; power take off/in; energy conversion effectiveness; diesel engine; mean value first principle engine model; engine dynamic behaviour; low-powered ship; ship operational safety; fuel consumption; emissions","en","doctoral thesis","","978-94-6421-410-9","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:ac6113f5-9777-49a3-b559-f14554ffc210","http://resolver.tudelft.nl/uuid:ac6113f5-9777-49a3-b559-f14554ffc210","To fold or not to fold?: An exploration of deployable porous biomaterials for the treatment of large bone defects","Bobbert, F.S.L. (TU Delft Biomaterials & Tissue Biomechanics)","Zadpoor, A.A. (promotor); Delft University of Technology (degree granting institution)","2021","Without our musculoskeletal system, which consists of bones, joints, and muscles, we would not be able to live. Our bones are responsible for the protection of our organs, the support of our body, and they enable our mobility. Therefore, it is important to keep them healthy. This is done by cells who repair small cracks and fractures caused by our daily activities through continuous remodeling of the skeleton. However, severe bone damage and defects can occur, for example, due to trauma (e.g., car accidents) and bone tumor resection. In this case, the defects are too large for the cells to repair and surgical intervention is required to support the bone regeneration process. Bone substitutes or porous biomaterials are used to fill these defects to help the cells to regenerate the bone. Bone substitutes require implantation via open surgery due to their large dimensions and rigidity. This causes great damage to the body, which results in a long recovery time for the patient and increases the risk of infections. To reduce the invasiveness of the implantation process, minimally invasive surgery (MIS) could be used. MIS techniques make it possible to perform surgical treatments through specific minimally invasive tools that are inserted into the body through small incisions. In order to make minimally invasive implantation possible, the dimensions of porous biomaterials should be reduced to fit through these small incisions. In addition, it has been demonstrated that the bone regeneration process can be optimized and infections could be prevented by applying precisely controlled nanopatterns to the surface of bone substitutes. However, surface patterning techniques can only be applied to flat surfaces. Therefore, it is not possible to apply surface patterns to the inner surfaces of three-dimensional porous structures, such as those fabricated through 3D printing techniques. To resolve","Bone tissue engineering; Deployable structures; Biomaterials; Origami; Kirigami","en","doctoral thesis","","978-94-6419-248-3","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b9241a98-34b9-4295-93e3-af8d4e796628","http://resolver.tudelft.nl/uuid:b9241a98-34b9-4295-93e3-af8d4e796628","Engineering of vitamin and cofactor synthesis in yeasts","Perli, T. (TU Delft BT/Industriele Microbiologie)","Pronk, J.T. (promotor); Daran, J.G. (promotor); Delft University of Technology (degree granting institution)","2021","The increase in world population together with an unsustainable and fossil fuel-based economy are at the root of the significant increase in the average global temperature since the pre-industrial era. Switching to a more sustainable and circular bio-based economy is one of the main pillars included in the Paris agreement aimed at reducing green-house gasses emissions in the next decades. Biotechnology promises to play a crucial role in this context by providing novel, more sustainable processes for the production of food, drugs, fuels and chemicals.","yeast; metabolic engineering; vitamin; cofactor","en","doctoral thesis","","978-94-6423-329-2","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:477df1e7-29fc-494b-af92-f5d63af87366","http://resolver.tudelft.nl/uuid:477df1e7-29fc-494b-af92-f5d63af87366","Tunable quantum interfaces between superconducting qubits and microwave photons induced by extreme driving","Ann, B. (TU Delft QN/Steele Lab)","Steele, G.A. (promotor); van der Sar, T. (copromotor); Delft University of Technology (degree granting institution)","2021","In this work, I investigate how to implement and quantify \emph{in-situ} tunable quantum interface between superconducting qubits and resonators using external transverse driving fields beyond the rotating wave approximation (RWA). When studying the system under the time-periodic driving field, we typically rely on RWA, a useful technique that significantly reduces the analytical difficulties in solving the dynamics with time-dependent Hamiltonian. Nonetheless, it does not correctly describe the systems' dynamics when the drive fields are excessively strong and far off-resonant. Especially in circuit QED platform, the RWA often breakdowns. Many studies before, however, mainly focus on the transition frequency shifts. How the RWA distorts the interaction rates between two systems has been rarely explored. I have performed quantitative studies over two different systems. One is the quantum Rabi model (QRM) where a two-level atom is dispersively coupled to a resonator mode. The other is dispersively coupled a transmon and resonator system, which is the same as the QRM except that the transmon replaces the two-level atom in QRM. In both cases, I have revealed that the RWA significantly mislead the sideband transition rates between two elements. In the latter case, I have performed the experiments, and the results nicely agree with the analytical and numerical calculations. In addition to these, I also have introduced a study where the tunable coupling between a transmon and resonator is used for non-invasive resonator probing.","Quantum engineering; Circuit quantum electrodynamics","en","doctoral thesis","","978-90-5934-481-3","","","","","","","","","QN/Steele Lab","","",""
"uuid:3c28e1fc-8b41-49eb-be8c-0c744604ac25","http://resolver.tudelft.nl/uuid:3c28e1fc-8b41-49eb-be8c-0c744604ac25","Factors regulating sediment fluxes over an engineered foredune and adjacent dune slack","Oude Vrielink, J.J. (University of Twente, Netherlands - Deltares, Netherlands - Arcadis, Netherlands); Eleveld, M.A. (Deltares, Netherlands); van Westen, B. (Deltares, Netherlands); Galiforni-Silva, F. (University of Twente, Netherlands - Christian-Albrechts-Universität zu Kiel, Germany); Wijnberg, K.M. (University of Twente, Netherlands)","","2021","This study aims to identify and understand the annual scale sediment transport patterns in a fully engineered dune-dune slack system that was created from seabed sediments for grey dune and moist dune slack habitat creation at the Delfland coast (the Netherlands). The annual morphological development was analysed using LiDAR elevation data. Daily aeolian sediment transport was simulated across the foredune and in the adjacent dune slack, using the numerical aeolian sediment transport model AeoLiS. All simulated transport events were combined to reveal how aeolian sediment transport behaves on an annual scale. Planting two continuous strips of marram grass along the top of the foredune induced rapid growth of the foredune, while limiting sediment supply to the dune slack. The armouring layer of shells that formed at the surface of the engineered topography, functioned as a supply-limiting factor and restricted the sediment entrainment and deflation of the dune slack. Therefore, the formation of a moist dune slack habitat may take longer for this engineered case than in a natural case with similar boundary conditions.","dune slack; Coastal sediment transport (subaqueous and aeolian); Nature-based solutions; Aeolian sediment transport; AeoLiS; engineered dunes; nature-based solutions; foredune","en","conference paper","","","","","","","","","","","","","",""
"uuid:6d8f6160-5e1c-4396-a6c2-0bc67c3858b9","http://resolver.tudelft.nl/uuid:6d8f6160-5e1c-4396-a6c2-0bc67c3858b9","The curious case of curvature: Geometric perspectives on biomaterial design","Callens, S.J.P. (TU Delft Biomaterials & Tissue Biomechanics)","Zadpoor, A.A. (promotor); Delft University of Technology (degree granting institution)","2021","The rapidly expanding field of tissue engineering presents enticing, yet demanding challenges for scientists and engineers across many different disciplines. The ultimate goal of tissue engineering is ambitious: to regenerate damaged or missing tissue in its full complexity, either in vitro or in situ, and restore organ function. In addition to cells and biochemical factors, biomaterial scaffolds form the other essential ingredient within the tissue engineering paradigm. These scaffolds support, guide, and stimulate neotissue formation and are rationally designed to meet the desired balance between mechanical, mass transport and biological properties necessary for regeneration and implantation.","bone tissue engineering; metabiomaterials; geometry; 4D printing","en","doctoral thesis","","978-94-6419-208-7","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:d7e16dc8-8892-4344-aba7-a754298ef8e2","http://resolver.tudelft.nl/uuid:d7e16dc8-8892-4344-aba7-a754298ef8e2","Emergent rotational dynamics and optical properties of metal–organic frameworks","Gonzalez Nelson, A.M. (TU Delft ChemE/Catalysis Engineering)","Kapteijn, F. (promotor); van der Veen, M.A. (promotor); Delft University of Technology (degree granting institution)","2021","Metal–organic frameworks (MOFs) are ordered arrays of polytopic organic ligands, commonly called linkers, which interconnect metal-based inorganic building units via coordination bonds. The highly precise assembly of well defined building blocks into extended 3-D networks, known as reticular chemistry, has allowed researchers in this field to produce tens of thousands of different frameworks. As an obvious consequence of their unprecedented porosity and tunability, these versatile materials are continuously studied with various potential applications in mind. An important portion of MOF research has been invested in the interaction between molecules and the framework, aiming for applications such as gas storage and separation, as well as catalysis, drug delivery, heat exchange, and water harvesting.
MOFs are considered soft or flexible materials, a characteristic that includes structural dynamics or large amplitude deformations. This flexibility can usually be attributed to the framework’s topology and the degrees of freedom of some of its bonds. However, the linkers themselves may also have degrees of freedom allowing independent molecular dynamics, in particular in the form of rotation. This type of dynamics is particularly common in MOFs because their porous architectures often provide enough space for the rotation of a molecular fragment to occur. It is this type of dynamics that this thesis is centered on, starting from the fact that, although it is an intriguing phenomenon that occurs in MOFs, it has remained relatively unexplored.
Nevertheless, the past four years have seen an increase in researchers’ interest in rotational dynamics in MOFs. This may be due to two main reasons: First, linker rotation influences MOF properties, not only when guest molecule interactions are involved, but also in optical and mechanical properties. Development of our knowledge on linker rotation is therefore essential for a more complete understanding of these materials’ properties and how they may be modified to enhance a specific trait. Second, the exploitation of linkers’ rotational freedom could potentially lead to important technological advances. The latter category includes various innovative ideas, such as the design of ferroelectric MOFs by means of controllable dipolar rotors, or the realization of crystalline molecular machines able to produce useful work.","metal-organic framework; molecular dynamics; Crystal engineering; Rotation behaviour","en","doctoral thesis","","978-94-6366-414-1","","","","","","","","","ChemE/Catalysis Engineering","","",""
"uuid:e7b360c1-fdb9-47c5-8f2f-486da3b44796","http://resolver.tudelft.nl/uuid:e7b360c1-fdb9-47c5-8f2f-486da3b44796","Strain hardening behaviour of PVA fibre reinforced geopolymer composites","Wang, Yi (University College London, UK); Zhang, Mingzhong (University College London, UK)","","2021","Strain hardening geopolymer composites (SHGC) as a tailored group of fibre reinforced geopolymer composites are featured by large tensile strain capacity with multiple micro-cracks. This paper experimentally investigates the strain hardening behaviour of SHGC in terms of flexural stress-deflection response, failure mode and cracking, flexural strength and toughening mechanisms. SHGC specimens were prepared using fly ash and slag with a weight ratio of 80:20 as the binder, a combination of NaOH and Na2SiO3 as the alkaline activator with the activator/binder ratio of 0.4. The effects of PVA fibre content (0, 1%, 1.5%, and 2%) and microsilica sand content (0, 10%, 20%, 30%, and 40%) on strain hardening behaviour of SHGC specimens were estimated. The toughening mechanisms (fibre bridging, rupture, and pull-out) and features of micro-cracks (number and width) distributed over the tensile side of specimens under four-point bending were characterised using digital microscope. Results indicate that all fibre reinforced specimens exhibited strain hardening behaviour with large deflection and multiple micro-cracks. The addition of PVA fibres up to 2% improved the strain hardening behaviour of SHGC and increased the flexural strength by 126% compared to SHGC specimen without fibre because of fibre bridging effect. The incorporation of microsilica sand up to 20% enhanced the flexural strength by 38.3% but further adding sand to 40% reduced the flexural strength of SHGC specimens. Overall, the SHGC specimen containing 2% PVA fibre and 20% micro-silica sand achieved the optimum strain hardening behaviour.","Toughness; Alkali-activated materials; Engineered geopolymer composites; Fibre reinforced concrete; Flexural behaviour","en","conference paper","","","","","","","","","","","","","",""
"uuid:2f633968-c018-44d4-a05c-0d513c86d8eb","http://resolver.tudelft.nl/uuid:2f633968-c018-44d4-a05c-0d513c86d8eb","In Pursuit of Success: Evaluating the Management of Engineering Projects, Cross-Sectoral Analysis of Project Management Efforts","Molaei, M.","Bakker, H.L.M. (promotor); Bosch-Rekveldt, M.G.C. (copromotor); Delft University of Technology (degree granting institution)","2021","Successful delivery of projects is the ultimate goal of many organisations. What is observed in practice, however, is that projects do not usually follow what is recommended in literature. Moreover, the dynamic nature of projects calls for continuous adjustments regarding the required project management practices contributing to performance. Therefore, this research aims at evaluating the current practice of managing engineering projects and investigating potential learning points across two main industry sectors: construction (including infrastructure) and process industry. The main output of this research is a model called “Nexcess model” that could help in improving project performance by providing practical recommendations. The model offers a space for interaction in which practitioners can understand the extent to which they can contribute positively to the performance by promoting an integrated approach.","Project management; project performance; engineering project; evaluation; cross-sector analysis","en","doctoral thesis","","978-94-6419-182-0","","","","","","2022-04-15","","","Integral Design & Management","","",""
"uuid:e5da9c8d-02ab-42e3-9480-9af6bd5a7d49","http://resolver.tudelft.nl/uuid:e5da9c8d-02ab-42e3-9480-9af6bd5a7d49","Data-Driven Software Engineering","Kovalenko, V.V. (TU Delft Software Engineering)","van Deursen, A. (promotor); Bacchelli, A. (promotor); Delft University of Technology (degree granting institution)","2021","Specialized tools, such as IDEs, issue trackers, and code review tools, are an indispensable part of the modern software engineering process. These tools are constantly evolving. Besides enabling tools to support a wider range of technologies and frameworks, we are learning to provide additional features in completely new ways. One prominent stream of innovation in software engineering tools is dedicated to utilizing historical data to enable data-driven features, such as defect prediction engines and recommender systems, which leverage records of prior activity to assist with decision making. Many data-driven features in software engineering tools initially get born out of the context of real-world tools as techniques devised and evaluated in synthetic settings by researchers. While convenient, synthetic evaluation of approaches that are ultimately aimed at bringing improvement to real world problems involves a number of simplifications and assumptions. In this dissertation, we highlight several aspects that, while vital for bringing innovative methods to software engineering tools, are often discarded in existing research. We closely explore several topics specific to artificial evaluation environments, such as simplifications in mining file modification histories, use of synthetic datasets for source code authorship attribution, and a gap between accuracy of reviewer recommendation models and their perception by users. Moreover, we make a case for sharing technical artifacts by converting data mining pipelines into reusable tools, and propose a novel approach to modeling expertise transfer from code modification by capturing individual contribution style of developers. Key contributions of this dissertation include a high-level model of the lifecycle of a data-driven software engineering technique, a discussion of dangerous assumptions and simplifications that are made on every step in this lifecycle, a demonstration of importance of a careful approach to mining software repositories, and a demonstration of serious misalignment between artificial evaluation and realistic environments for the problems of code reviewer recommendation and code authorship attribution. We conclude the dissertation by discussing underlying reasons for misalignment between research environments and real-world tools, and propose potential steps to narrow it down and ultimately accelerate innovation in software engineering tooling.","Data-Driven Software Engineering","en","doctoral thesis","","","","","","","","","","","Software Engineering","","",""
"uuid:9efdc813-e4a7-4a29-9023-1b95b498ca2a","http://resolver.tudelft.nl/uuid:9efdc813-e4a7-4a29-9023-1b95b498ca2a","Computational optical imaging based on helical point spread functions","Berlich, R. (TU Delft ImPhys/Computational Imaging)","Stallinga, S. (promotor); Pereira, S.F. (copromotor); Delft University of Technology (degree granting institution)","2021","Helical point spread functions (PSFs) provide a powerful computational imaging tool for modern optical imaging and sensing applications. However, their utilization is, so far, limited to a single field of application, i.e. super-resolution microscopy, which is due to multiple shortcomings in their current system implementation. A new computational imaging approach is developed in this thesis, which enables the utilization of helical PSFs and their unique advantages for applications in the area of machine vision. In particular, the approach can be used to acquire the three-dimensional distribution of a passively illuminated, extended scene in a single shot based on a compact, monocular camera setup. A novel image processing routine is established to overcome a major challenge of computational imaging using helical PSFs, i.e. the retrieval of the PSF rotation angle in the case of an extended object distribution. The hardware implementation of computational imaging setups that rely on helical PSFs is based on a combination of a conventional optical element, such as a microscope objective or a camera lens, and an additional, dedicated pupil mask. This mask is commonly realized using either a spatial light modulator or a lithographic element that features a structured surface profile. Two new fabrication schemes with different advantages are explored in this thesis. The first scheme utilizes wafer-scale optical lithography in combination with UV-replication in order to fabricate highly cost efficient phase elements. The second method is based on femto-second laser direct writing. It enables the inscription of the phase element directly inside a transparent optical element using a single fabrication step. Therefore, it facilitates a flexible realization of highly integrated PSF engineered optical systems. Current design concepts for pupil masks that generate helical PSFs only focus on doublehelix distributions that feature two, laterally separated irradiance peaks. Furthermore, a diffraction limited performance of the computational imaging system is assumed. A new design method that enables the generation of multi-order-helix PSFs with an arbitrary number of rotating peaks is developed in this thesis. A study of the influence of first order aberrations on the rotation angle of multi-order-helix PSFs is performed in order to assess their effect on the accuracy limits with respect to three-dimensional imaging. In this context, the superior aberration robustness of high-order-helix PSFs featuring three or more rotating spots is demonstrated. Whereas, on the one hand, the effect of aberrations on helical PSFs degrade the depth retrieval accuracy of three-dimensional imaging systems, their influence can be explored in order to obtain information on the system’s wavefront aberrations on the other hand. To this end, the computational imaging approach developed for three-dimensional imaging is extended and combined with a conventional phase diversity method. The novel approach enables a numerically efficient estimation of general wavefront aberrations based on the acquisition of an extended, unknown object scene. In summary, the research performed in this thesis provides the foundation to exploit the unique advantages of computational imaging systems based on helical PSFs for applications in the area of three-dimensional imaging and wavefront sensing.","Computational imaging; PSF engineering","en","doctoral thesis","","978-94-6416-444-2","","","","","","","","","ImPhys/Computational Imaging","","",""
"uuid:9db1a0c4-89ba-4f9b-b32a-47b7bca5b55e","http://resolver.tudelft.nl/uuid:9db1a0c4-89ba-4f9b-b32a-47b7bca5b55e","Location-Based Games For Social Interaction In Public Space","Fonseca, Xavier (TU Delft System Engineering)","Brazier, F.M. (promotor); Lukosch, S.G. (promotor); Helbing, D. (promotor); Delft University of Technology (degree granting institution)","2021","This thesis broadens current understanding of how location-based games can promote meaningful social interaction in citizens' own neighbourhoods. It investigates social cohesion and the role of social interaction to its promotion, delves into which requirements users have for playing in their neighbourhood and with its citizens, and takes a technical perspective into how this type of games should be designed to be successful at triggering interaction in public space. From this understanding, which stems from adolescents and adults from Rotterdam and The Hague, NL, a specific design and prototype of a location-based game is proposed and tested. This thesis addresses several gaps found in the current body of knowledge. On the one hand, meaningful interactions are person-dependent, can occur in various forms, and their impact on societies is not well understood. On the other hand, it is not well understood how to build location-based games for such aim: it is not known which requirements should be considered, attempts to build location-based games are often a product of in-house development not centred early on around users, no known guidelines exist for meaningful social interaction, and no consensus exists on what to consider when building location-based games from a technical perspective.
This thesis offers learnings on how to best design location-based games to promote interaction that matters to local communities. It firstly offers an overview of social cohesion and how multiple factors and actors have the power to influence local communities. It then argues that meaningful social interaction bears the power to break down stereotypes and prejudice, empowers people's agencies to act, has a positive impact on cohesion, emerges at people's own pace, and addresses conflict. From this, it dives into the preferences, needs and desires of adolescents and adults to better understand what sorts of interactions are meaningful to them. This thesis explores throughout several case studies the requirements that these target groups have, and advances gameplay dynamics and game activity types that location-based games should implement to be successful at inviting meaningful social interaction in public space. These case studies also research different sorts of interaction that each game activity type invites players to have, and elicit specific game ideas that are particularly tailored around perceived-to-be socially challenging neighbourhoods in The Netherlands. These case studies culminate in the recommendation of several guidelines to be used at different stages of the game design: gameplay requirements, guidelines for meaningful social interaction to occur in the studied groups, and the sorts of game activities that designers should include to invite specific forms of social interaction. This thesis also proposes a systems architecture with key architectural components, to drive consensus and inform on what to consider when building location-based games for this purpose from a technical perspective.
The lessons learned that are advanced in this thesis help practitioners design location-based games that are more tailored to what future players want to play, and help researchers understand what it means to design for meaningful social interaction in any public space around the world. Players have distinct preferences with regard to the ways they are exposed to their own neighbourhood, and the forms of interaction they would rather experience. Understanding this, and incorporating such preferences in game design, lead to gameplay experiences that can have a positive effect on societies, as they have the power to promote interaction and positive relationships in local communities. These gameplay experiences invite individuals to come together and have meaningful interactions in a playful way, (re)engage with their own neighbourhood, and be part of their local community.","Location-based Games; Serious Games; Software architecture; Requirements Engineering; Social Interaction; social cohesion; Meaningfulness; Public Space","en","doctoral thesis","","978-94-6421-198-6","","","","","","","","","System Engineering","","",""
"uuid:2566b982-377b-4f5a-9ca7-09e02b0396a4","http://resolver.tudelft.nl/uuid:2566b982-377b-4f5a-9ca7-09e02b0396a4","Inside the Matrix: CTI Frameworks as Partial Abstractions of Complex Threats","Oosthoek, K. (TU Delft Cyber Security); Dörr, C. (Hasso Plattner Institute)","","2021","The Cyber Threat Intelligence (CTI) field has evolved rapidly and most of its reporting is now fairly stan-dardized. Where the Cyber Kill Chain was its sole reference framework 5 years ago, today ATT&CK is the de facto standard for reporting adversary tactics, techniques and procedures (TTPs). CTI frameworks are effectively abstraction layers of malicious behavior and thus effective CTI dissemination hinges on their ability to accurately represent this behavior. We argue that this is an area with significant opportunity for improvement. The aforementioned models are attacker- and intrusion-centric, while much of the CTI reporting currently is artifact- and malware-centric. In other words, most analysis is performed using artifacts of adversary tools, while in-the-wild evidence of adversary techniques and procedures is limited or lacking. Applying an intrusion model to artifact-based analysis leads to information loss, affecting and potentially misleading CTI-based decision-making. Intelligence analysis naturally builds on imperfect information, but CTI frameworks should be oriented more towards this key premise. In this conceptual work we compare the intrusion-centric ATT&CK with Malware Behavior Catalog (MBC), which is malware-centric. We compare how their application affects reporting of analysis outcomes. For this we reverse a piece of APT malware, replicating how many CTI reports are produced. We find that compared to ATT&CK, the abstraction offered by MBC enhances the information density of our reporting. While currently in most industry malware reports ATT&CK is applied, our analysis shows that on these occasions using MBC, potentially in tandem with ATT&CK, improves reporting. With the daily amount of new malware samples only increasing, accurate behavior labeling is key to the success of CTI sharing and dissemination.","malware analysis; cyber threat intelligence; Mal-ware Behavior Catalog (MBC); ATT&CK; reverse engineering","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Cyber Security","","",""
"uuid:448302bd-00ad-4cb1-a788-b3549d7576ac","http://resolver.tudelft.nl/uuid:448302bd-00ad-4cb1-a788-b3549d7576ac","Bioprinting of a Zonal-Specific Cell Density Scaffold: A Biomimetic Approach for Cartilage Tissue Engineering","Dimaraki, A. (Student TU Delft); Diaz Payno, P.J. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Minneboo, M.B. (TU Delft Biomaterials & Tissue Biomechanics); Nouri Goushki, M. (TU Delft Biomaterials & Tissue Biomechanics); Hosseini, M. (TU Delft Biomaterials & Tissue Biomechanics; Azarbaijan Shahid Madani University); Kops, N. (Erasmus MC); Narcisi, R. (Erasmus MC); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","The treatment of articular cartilage defects remains a significant clinical challenge. This is partially due to current tissue engineering strategies failing to recapitulate native organization. Articular cartilage is a graded tissue with three layers exhibiting different cell densities: the superficial zone having the highest density and the deep zone having the lowest density. However, the introduction of cell gradients for cartilage tissue engineering, which could promote a more biomimetic environment, has not been widely explored. Here, we aimed to bioprint a scaffold with different zonal cell densities to mimic the organization of articular cartilage. The scaffold was bioprinted using an alginate-based bioink containing human articular chondrocytes. The scaffold design included three cell densities, one per zone: 20 × 106 (superficial), 10 × 106 (middle), and 5 × 106 (deep) cells/mL. The scaffold was cultured in a chondrogenic medium for 25 days and analyzed by live/dead assay and histology. The live/dead analysis showed the ability to generate a zonal cell density with high viability. Histological analysis revealed a smooth transition between the zones in terms of cell distribution and a higher sulphated glycosaminoglycan deposition in the highest cell density zone. These findings pave the way toward bioprinting complex zonal cartilage scaffolds as single units, thereby advancing the translation of cartilage tissue engineering into clinical practice.","bioprinting; biofabrication; tissue engineering; articular cartilage; human chondrocytes; cell density; cell gradient","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:ca726d07-4cf3-4180-997b-80772c2d7bd7","http://resolver.tudelft.nl/uuid:ca726d07-4cf3-4180-997b-80772c2d7bd7","Analytical Models to Determine In-Plane Damage Initiation and Force Capacity of Masonry Walls with Openings","Drougkas, A. (TU Delft Applied Mechanics); Esposito, R. (TU Delft Applied Mechanics); Messali, F. (TU Delft Applied Mechanics); Sarhosis, Vasilis (University of Leeds)","","2021","Masonry panels consisting of piers and spandrels in buildings are vulnerable to in-plane actions caused by seismicity and soil subsidence. Tectonic seismicity is a safety hazard for masonry structures, whereas low-magnitude induced seismicity can be detrimental to their durability due to the accumulation of light damage. This is particularly true in the case of unreinforced masonry. Therefore, the development of models for the accurate prediction of both damage initiation and force capacity for masonry elements and structures is necessary. In this study, a method was developed based on analytical modeling for the prediction of the damage initiation mode and capacity of stand-alone masonry piers; the model was then expanded through a modular approach to masonry walls with asymmetric openings. The models account for all potential damage and failure modes for in-plane loaded walls. The stand-alone piers model is applicable to all types of masonry construction. The model for walls with openings can be applied as is to simple buildings but can also be extended to more complex structures with simple modifications. Model results were compared with numerous experimental cases and exhibited very good accuracy.","Analytical modeling; Earthquake engineering; In-plane loading; Limit analysis; Masonry","en","journal article","","","","","","Accepted Author Manuscript","","","","","Applied Mechanics","","",""
"uuid:90a0ac28-a286-420d-bdec-6f6bf2a87b17","http://resolver.tudelft.nl/uuid:90a0ac28-a286-420d-bdec-6f6bf2a87b17","Breakdown of Engineering Projects' Success Criteria","Radujković, Mladen (International Doctoral Study in Project Management); Sjekavica Klepo, Mariela (Hrvatske Vode); Bosch-Rekveldt, M.G.C. (TU Delft Integral Design & Management)","","2021","This paper presents the findings from a study of the breakdown of project success criteria. An exploration of the evolution of studies on the success of engineering projects over decades was the basis for a project success definition proposal. Using a comprehensive literature review of success criteria for engineering projects, a list of 133 different success criteria was identified. Those criteria were analyzed to develop an integrated framework of project success criteria, describing its hierarchical decomposition. Such a breakdown structure could serve as a starting point when setting project success criteria for a specific project, because the importance of criteria will be context dependent. Practitioners or stakeholders could discuss and tailor it based on specific features of engineering projects or specific needs and interests. Generally, criteria have evolved from simple work-related factors to focusing more on the complex benefits of the projects. Such an evolving success definition has implications for further studies of project success and might contribute toward a long-term vision in which all projects will be delivered successfully.","Breakdown; Engineering projects; Success; Success criteria","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-02-26","","","Integral Design & Management","","",""
"uuid:a1244e8e-c3a9-484d-8b51-942e9cd35c67","http://resolver.tudelft.nl/uuid:a1244e8e-c3a9-484d-8b51-942e9cd35c67","Improving Test Case Generation for REST APIs Through Hierarchical Clustering","Stallenberg, D.M. (TU Delft Software Engineering); Olsthoorn, Mitchell (TU Delft Software Engineering); Panichella, A. (TU Delft Software Engineering)","","2021","With the ever-increasing use of web APIs in modern-day applications, it is becoming more important to test the system as a whole. In the last decade, tools and approaches have been proposed to automate the creation of system-level test cases for these APIs using evolutionary algorithms (EAs). One of the limiting factors of EAs is that the genetic operators (crossover and mutation) are fully randomized, potentially breaking promising patterns in the sequences of API requests discovered during the search. Breaking these patterns has a negative impact on the effectiveness of the test case generation process. To address this limitation, this paper proposes a new approach that uses agglomerative hierarchical clustering (AHC) to infer a linkage tree model, which captures, replicates, and preserves these patterns in new test cases. We evaluate our approach, called LT-MOSA, by performing an empirical study on 7 real-world benchmark applications w.r.t. branch coverage and real-fault detection capability. We also compare LT-MOSA with the two existing state-of-the-art white-box techniques (MIO, MOSA) for REST API testing. Our results show that LT-MOSA achieves a statistically significant increase in test target coverage (i.e., lines and branches) compared to MIO and MOSA in 4 and 5 out of 7 applications, respectively. Furthermore, LT-MOSA discovers 27 and 18 unique real-faults that are left undetected by MIO and MOSA, respectively.","System-level testing; Machine Learning; Test Case Generation; Search-based Software Engineering; Hierarchical clustering","en","conference paper","IEEE","","","","","","","","","","Software Engineering","","",""
"uuid:fb773461-fa1b-41e3-87da-028b5bff9d8a","http://resolver.tudelft.nl/uuid:fb773461-fa1b-41e3-87da-028b5bff9d8a","Learning Off-By-One Mistakes: An Empirical Study","Sellik, Hendrig (Student TU Delft); van Paridon, Onno (Adyen B.V.); Gousios, G. (TU Delft Software Engineering); Aniche, Maurício (TU Delft Software Engineering)","O'Conner, L. (editor)","2021","Mistakes in binary conditions are a source of error in many software systems. They happen when developers use, e.g., < or > instead of <= or >=. These boundary mistakes are hard to find and impose manual, labor-intensive work for software developers. While previous research has been proposing solutions to identify errors in boundary conditions, the problem remains open. In this paper, we explore the effectiveness of deep learning models in learning and predicting mistakes in boundary conditions. We train different models on approximately 1.6M examples with faults in different boundary conditions. We achieve a precision of 85% and a recall of 84% on a balanced dataset, but lower numbers in an imbalanced dataset. We also perform tests on 41 real-world boundary condition bugs found from GitHub, where the model shows only a modest performance. Finally, we test the model on a large-scale Java code base from Adyen, our industrial partner. The model reported 36 buggy methods, but none of them were confirmed by developers.","Boundary testing; Deep learning for software engineering; Machine learning for software engineering; Software testing","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Software Engineering","","",""
"uuid:7b76dd49-6809-4a32-9ca1-6196d2434017","http://resolver.tudelft.nl/uuid:7b76dd49-6809-4a32-9ca1-6196d2434017","From cyclic sand ratcheting to tilt accumulation of offshore monopiles: 3D FE modelling using SANISAND-MS","Liu, H. (Norwegian Geotechnical Institute); Kementzetzidis, E. (TU Delft Offshore Engineering); Abell, J. A. (Universidad de los Andes); Pisano, F. (TU Delft Geo-engineering)","","2021","Serviceability criteria for offshore monopiles include the estimation of long-term, permanent tilt under repeated operational loads. In the lack of well-established analysis methods, experimental and numerical research has been carried out in the last decade to support the fundamental understanding of monopile-soil interaction mechanisms, and the conception of engineering methods for monopile tilt predictions. With a focus on the case of monopiles in sand, this work shows how step-by-step/implicit, three-dimensional (3D) finite-element (FE) modelling can be fruitfully applied to the analysis of cyclic monopile-soil interaction and related soil deformation mechanisms. To achieve adequate simulation of cyclic sand ratcheting and densification around the pile, the recently proposed SANISAND-MS model is adopted. The link between local soil behaviour and global monopile response to cyclic loading is discussed through detailed analysis of model prediction. Overall, the results of numerical parametric studies confirm that the proposed 3D FE modelling framework can reproduce relevant experimental evidence about monopile-soil interaction, and support future improvement of engineering design methods.","constitutive relations; finite-element modelling; footings/foundations; offshore engineering; repeated loading","en","journal article","","","","","","Accepted author manuscript","","2022-03-08","","","Offshore Engineering","","",""
"uuid:a332cb52-8cb8-4080-ad7b-1d858e5d4243","http://resolver.tudelft.nl/uuid:a332cb52-8cb8-4080-ad7b-1d858e5d4243","The resurgence of business process re-engineering in public sector transformation efforts: exploring the systemic challenges and unintended consequences","Weerakkody, Vishanth (Bradford University); Janssen, M.F.W.H.A. (TU Delft Information and Communication Technology); El-Haddadeh, Ramzi (Qatar University)","","2021","The realisation of citizen-centric services in the public sector requires breaking traditional silos and transforming existing institutional structures and processes. Recent transformation efforts undertaken in government institutions have embraced business process re-engineering (BPR) concepts championed by the private sector over decades ago to facilitate such change. While public opinion continues to differ about these transformation efforts' success, there is little evidence to explain the influence of BPR on their success or failure. This paper explores BPR led public sector transformation efforts in two local authorities in Europe to evaluate the outcomes realised for both government and citizens. Empirical evidence reveals that while transformation efforts contributed towards improving efficiency and integrating processes across functions in the public sector, the institutional structures evolved into a collection of reshaped and newly formed siloes, which were distinctly focused on delivering a citizen-centric service.","BPR; Business process re-engineering; Citizen centric; Public sector; Silos; Transformation","en","journal article","","","","","","","","","","","Information and Communication Technology","","",""
"uuid:36b3c294-9c46-41e9-b6aa-e132fb8cf040","http://resolver.tudelft.nl/uuid:36b3c294-9c46-41e9-b6aa-e132fb8cf040","A mechanism for the increased wave-induced drift of floating marine litter","Calvert, R. (University of Oxford; University of Edinburgh); McAllister, M. L. (University of Oxford); Whittaker, C. (The University of Auckland); Raby, A. (Plymouth University); Borthwick, A. G.L. (University of Edinburgh); van den Bremer, T.S. (TU Delft Environmental Fluid Mechanics; University of Oxford)","","2021","Periodic water waves generate Stokes drift as manifest from the orbits of Lagrangian particles not fully closing. Stokes drift can contribute to the transport of floating marine litter, including plastic. Previously, marine litter objects have been considered to be perfect Lagrangian tracers, travelling with the Stokes drift of the waves. However, floating marine litter objects have large ranges of sizes and densities, which potentially result in different rates of transport by waves due to the non-Lagrangian behaviour of the objects. Through a combination of theory and experiments for idealised spherical objects in deep-water waves, we show that different objects are transported at different rates depending on their size and density, and that larger buoyant objects can have increased drift compared with Lagrangian tracers. We show that the mechanism for the increased drift observed in our experiments comprises the variable submergence and the corresponding dynamic buoyancy force components in a direction perpendicular to the local water surface. This leads to an amplification of the drift of these objects compared to the Stokes drift when averaged over the wave cycle. Using an expansion in wave steepness, we derive a closed-form approximation for this increased drift, which can be included in ocean-scale models of marine litter transport.","coastal engineering; ocean processes; surface gravity waves","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-09-18","","","Environmental Fluid Mechanics","","",""
"uuid:214cceb6-a7ba-4512-8cca-d49cd011111f","http://resolver.tudelft.nl/uuid:214cceb6-a7ba-4512-8cca-d49cd011111f","Bezwijken Grimburgwal: Leerpunten voor het Amsterdamse areaal","Korff, M. (TU Delft Geo-engineering); Hemel, M. (TU Delft Hydraulic Structures and Flood Risk); Esposito, R. (TU Delft Applied Mechanics)","","2021","In dit rapport is via een forensic engineering aanpak een eerste analyse gegeven (rapid assessment, RA) van het bezwijken van de Grimburgwal (GBW) op 1 september 2020. Het doel van het onderzoek is om te achterhalen welke lessen zijn te leren van het bezwijken van de Grimburgwal voor de overige kades in Amsterdam. De volgende onderzoeksvragen zijn in dit onderzoek beantwoord op basis van de in dit rapport gepresenteerde informatie en analyses. Hierbij dient te worden aangegeven dat veel duidelijk is geworden maar dat ook nog gegevens ontbreken. Verder zijn alleen analyses uitgevoerd die in deze fase van Rapid Assessment konden worden uitgevoerd. Op basis hiervan is de beantwoording van de onderzoeksvragen als volgt:
Beantwoording vraag 1: Welke faalmechanisme(n) hebben significant bijgedragen aan het bezwijken van de Grimburgwal?
De Grimburgwal kade is in september 2020 in verschillende fasen bezweken. Als eerste was er sprake van een horizontale vervorming van de kade en enige dagen voor bezwijken zijn gaten in het straatwerk aangetroffen. De kade is daarna via een verticale vervorming losgeraakt en uit het vlak richting de gracht gevallen. Hierbij is een sectie van circa 25 m geheel onder water verdwenen. Het bezwijken is aan het oostelijke deel begonnen. Het westelijke deel is als gevolg daarvan
meegetrokken en gekanteld.
Als belangrijkste faalmechanisme is opgetreden een horizontale buigvervorming van de houten paalfundering gevolgd door het breken van de houten palen. De vervorming is het gevolg van een lokaal diepere bodemligging van de gracht. Deze verklaring berust op de verwachting dat er in elk geval onder een gedeelte van de kade slechts twee palenrijen achter elkaar aanwezig waren dan wel effectief functioneerden. Dit is conform het bestek, de duikinspectie en is tevens aannemelijk gezien de zeer korte afstand van de kade tot het pand BG2. Door bestaande scheurvorming was de mogelijkheid tot herverdeling van de krachten langs de kade in langsrichting verminderd, waardoor de sterkere delen (met wèl drie palenrijen) niet meer in staat waren de belasting over te nemen. De analyses zijn uitgevoerd met als aanname een ongedegradeerde houtsterkte. De sterkte van het hout was nog niet vastgesteld bij publicatie van dit rapport.
Beantwoording vraag 2: Wat zijn de onderliggende oorzaken van deze mechanismen?
De oorzaak van de diepere bodemligging is in dit onderzoek niet onderzocht. Naar alle waarschijnlijkheid is het draaien van boten een logische oorzaak hiervoor, omdat de instorting precies nabij het draaipunt voor brug 201 heeft plaatsgevonden. Het is waargenomen dat de diepte van de gracht in de richting van de brug toeneemt en daarna weer afneemt. De herhaaldelijke aanvaringen hebben de kade verzwakt, wat mogelijk verklaart waarom deze precies op de plaats van de schade als eerste is gescheurd. Tevens is dit het smalste deel van de kade, met mogelijk slechts twee palenrijen. Er lijkt geen sprake van belangrijke mate van aantasting van het hout (op basis van inspecties). De trigger (het laatste duwtje) voor de instorting is waarschijnlijk het vernieuwen van het straatwerk geweest van (eerst mei en later) augustus 2020. Het straatwerk zorgt voor een extra belasting op de kade. Dit straatwerk was nodig als gevolg van de reeds opgetreden kadevervorming. De bijdrage van de rondwaterstroming en eventuele droogte/regen is niet bekend, doch kan een rol hebben gespeeld in combinatie met de al opgetreden vervorming en ontstane lekweg van achter de kade richting de gracht voor de vorming van de gaten in het straatwerk. De gebroken hemelwaterafvoer is zeer waarschijnlijk een gevolg en geen oorzaak van de instorting.
Beantwoording vraag 3: Op welke manier zijn de resultaten van dit onderzoek in te zetten voor beoordeling van de veiligheid en het nemen van maatregelen voor de overige kademuren in Amsterdam?
Uit deze Rapid Assessment is gebleken dat de geometrie van de kade een belangrijke bijdrage heeft gespeeld in de gevoeligheid van de kade voor ontgronding/verdieping van de gracht. Door de combinatie van een kade die mogelijk op twee palen en zeker deels op drie palen rust is een uitspraak over de representativiteit van deze kade niet met volledige zekerheid te doen. De kade had volgens afdeling monumenten van Amsterdam (MenA) sowieso een wat afwijkende opbouw en een kade(deel) met twee palen is zelfs sterk afwijkend van het gebruikelijke areaal. Op basis van de bij vraag 1 en 2 beschreven mechanismen en oorzaken die ook voor de kade met drie palen gelden, kan desondanks worden gesteld dat maatregelen die voor de Grimburgwal worden aanbevolen ook voor overige kades van toepassing zijn.
Uit deze Rapid Assessment is gebleken dat de geometrie van de kade een belangrijke bijdrage heeft gespeeld in de gevoeligheid van de kade voor ontgronding/verdieping van de gracht. Hieruit volgen de volgende mogelijke
maatregelen/vervolgacties:
- Controle of er (meer) kades met korte kespen / vloerconstructies zijn en slechts twee palenrijen. Deze zijn kwetsbaarder dan de constructies met meer rijen palen. Deze kades kunnen met voorrang worden getoetst en zonodig versterkt.
- Uitvoeren van een controle op de waterdiepte en ontgrondingen, vooral op routes van scheepvaart en bij kades met twee of drie palenrijen. Er kunnen dan maatregelen genomen worden bij een te grote waterdiepte/ontgronding.
- Locaties met aanvaarschades met voorrang te onderzoeken.
- Systematisch aandacht te besteden aan zettingen achter de kades en problemen met leidingen of riolering, omdat dit kan duiden op het horizontaal vervormen van de kade, al dan niet door een diepere bodemligging. Er kan bijvoorbeeld een registratie/meldingssysteem gebruikt worden voor het optreden van verzakkingen aan de kades/het straatwerk. Als er een opdracht tot herstraten wordt gegeven dient altijd EERST een analyse van de oorzaak van de verzakking te worden gemaakt die het gedrag van de kade meeneemt. Dit kan ook voorkomen dat herstraatwerk tot vergroting van de belasting
op de kade leidt.
- Uitvoeren van metingen (liefst horizontaal aan de kades maar ook verticaal) om de relatie van de vervorming met mogelijk falen te onderzoeken (numeriek of experimenteel). Analyse van de zakkingen van de kades met Insarmetingen
kan helpen om andere “hotspots” in kaart te brengen. Door middel van nadere analyses dient te worden vastgesteld welke grenswaarden een indicatie voor falen geven. Het effect van droogte op de zakkingen in de stad dient hierbij mede te worden onderzocht.
In het onderzoek van de GBW is gebleken dat er veel factoren mogelijk een bijdrage hebben geleverd aan het falen. Enkele daarvan konden niet worden uitgesloten maar zijn ook niet bevestigd. Dit geeft wel aan dat bepaalde zaken nog nader onderzocht kunnen worden. Aan de GBW was een oude kade aanwezig die de huidige kade kruiste nabij de locatie van bezwijken. Ook voor andere kades zijn dergelijke vervangingen gangbaar geweest. De exacte samenstelling van de kade op het punt van bezwijken (met twee of drie palen) is ook niet geheel zeker, ondanks diverse inspanningen hier duidelijkheid over te krijgen. Nader onderzoek naar de (invloed van de) opbouw van bestaande kades, zowel archeologisch als modelmatig wordt sterk aanbevolen.
Om voor de Grimburgwal de relatieve invloed van de verschillende factoren nog specifieker te onderscheiden zouden de volgende activiteiten kunnen worden uitgevoerd:
- Onderzoek op houten samples uit de restanten om deze te drogen en te wegen en tevens trekproeven te doen om de buigtreksterkte sterkteklasse vast te stellen. Ook de mechanische eigenschappen van de paal-kesp verbinding kan
worden onderzocht.
- Onderzoek naar de exacte opbouw van de fundering in de bezweken en aanpalende gedeeltes.
- (na bovenstaande) Niet lineair eindig elementen model in 3D van de gehele kade voor het analyseren van de geschetste bezwijkmechanismen uit de RA en daarna variëren met verschillende scenario’s zoals andere geometrieën
Het is in dit onderzoek goed mogelijk gebleken met verschillende ekenmethoden een indruk te krijgen van de stabiliteit van de kade. Doorontwikkeling en validatie van modellen voor gecombineerde berekening van de gehele constructie (vloer, metselwerk, palen) is nodig, omdat deze gecombineerde modellen geen gemeengoed zijn.
Structures and Materials started on edX. This MOOC generally attracts a mixture of young aviation enthusiasts (often students) and aviation professionals. Given the large interest MOOCs have received as the pandemic hit, we investigate how the new global context affected the motivation and the way learners interact with our course material. For this project, we will use learning analytics approaches to
analyse the log data available from the edX platform and the data from pre- and
post-course evaluations of two runs of the same MOOC (2019 and 2020).
With the insights gathered through this analysis, we wish to better understand our learners and adjust the learning design of the course to better suit their needs. Our paper will present the first insights of this analysis.","Methods; formats and essential elements for online/blended learning; Social aspects and communication in online/blended learning; MOOC; Lifelong Learning; Learning Analytics; Aerospace Engineering","en","conference paper","","","","","","","","","","Aerospace Structures & Materials","Web Information Systems","","",""
"uuid:4f5334e6-c7ee-490b-9eb8-d12e93913ab2","http://resolver.tudelft.nl/uuid:4f5334e6-c7ee-490b-9eb8-d12e93913ab2","Building with Nature & Beyond: Principles for Designing Nature Based Engineering Solutions","Slinger, J (TU Delft Policy Analysis)","","2021","This book is based upon the edX MOOCs Engineering: Building with Nature and Beyond Engineering: Building with Nature. The Engineering: Building with Nature MOOC explores the use of natural materials and ecological processes in achieving effective and sustainable hydraulic infrastructure designs, distilling Engineering and Ecological Design Principles. In the Beyond Engineering: Building with Nature course, the missing element of Social Design Principles is developed and taught.
Join us in exploring the interface between hydraulic engineering, nature and society!","Nature Based solutions; Transdisciplinary; Community based; Stakeholder inclusion; Integrated design; Social design principles; Building with Nature; Ecosystem based; Hydraulic engineering design principles; Ecological design principles; Game theory; Coalition building; Sustainable Ports in Africa; Co-design; Co-creation; Netherlands; Ecosystem Based Approach; Engineering with Nature","en","book","TU Delft OPEN Publishing","978-94-6366-458-5","","","","","","","","","Policy Analysis","","",""
"uuid:55ffc3f2-175b-407e-881f-2d288b863f26","http://resolver.tudelft.nl/uuid:55ffc3f2-175b-407e-881f-2d288b863f26","Pedagogies of integration in challenge based or interdisciplinary education","Klaassen, R.G. (TU Delft Teaching & Learning Services; 4TU.Centre for Engineering Education)","Heiss, Hans-Ulrich (editor); Jarvinen, Hannu-Matti (editor); Mayer, Annette (editor); Schulz, Alexandra (editor)","2021","Integration is key characteristic of Interdisciplinary learning and often also of Challenge based Education. The definition and operationalisation in Engineering Education is, however debated widely. In this study we explored the tacit knowledge of Engineering Lecturers in HE education by doing semi-structured interviews. It yields suggestions for operationalising integration, boundary conditions and a peak insight into the beliefs and match with theoretical literature.","Interdisciplinary learning; Engineering; integration; curriculum HE","en","conference paper","SEFI","","","","","","","","","","Teaching & Learning Services","","",""
"uuid:7ab6cdfc-249b-4cc3-921f-90e1916e5158","http://resolver.tudelft.nl/uuid:7ab6cdfc-249b-4cc3-921f-90e1916e5158","How Developers Engineer Test Cases: An Observational Study","Aniche, Maurício (TU Delft Software Engineering); Treude, Christoph (University of Adelaide); Zaidman, A.E. (TU Delft Software Engineering)","","2021","One of the main challenges that developers face when testing their systems lies in engineering test cases that are good enough to reveal bugs. And while our body of knowledge on software testing and automated test case generation is already quite significant, in practice, developers are still the ones responsible for engineering test cases manually. Therefore, understanding the developers' thought- and decision-making processes while engineering test cases is a fundamental step in making developers better at testing software. In this paper, we observe 13 developers thinking-aloud while testing different real-world open-source methods, and use these observations to explain how developers engineer test cases. We then challenge and augment our main findings by surveying 72 software developers on their testing practices. We discuss our results from three different angles. First, we propose a general framework that explains how developers reason about testing. Second, we propose and describe in detail the three different overarching strategies that developers apply when testing. Third, we compare and relate our observations with the existing body of knowledge and propose future studies that would advance our knowledge on the topic.","Codes; Computer bugs; developer testing; Documentation; Software; software engineering; software testing; Software testing; Task analysis; Tools","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-07-01","","","Software Engineering","","",""
"uuid:af0c53ce-37b8-47e3-bb74-095413694110","http://resolver.tudelft.nl/uuid:af0c53ce-37b8-47e3-bb74-095413694110","Towards All-Polymeric Cochlear Implant Micro-Electrode Arrays","Miralles-Abete, Alberto (Student TU Delft); French, P.J. (TU Delft Bio-Electronics)","","2021","This paper shows that PEDOT:PSS is an excellent material for all-polymeric cochlear implant micro-electrode arrays. Initial experiments have shown a high conductivity of 230 S/cm for PEDOT:PSS samples, which dramatically decreased to 0.48 S/cm after 3 hours of UV treatment. Electrical characterisation of PEDOT:PSS electrodes reveals that its maximum charge injection capacity is 15 times higher than that of platinum, the electrode material used in commercial cochlear implants. These experiments demonstrate that PEDOT:PSS is an excellent candidate material for cochlear implants, both as micro-electrode and insulating layer.","BioMedical Engineering; Cochlear Implants; Micro-Electrodes; PEDOT:PSS","en","conference paper","IEEE","","","","","","","","","","Bio-Electronics","","",""
"uuid:ee1569f6-cdb1-4336-9143-fbafe298dbe2","http://resolver.tudelft.nl/uuid:ee1569f6-cdb1-4336-9143-fbafe298dbe2","Asking Effective Questions: Awareness of Bias in Designerly Thinking","Price, R.A. (TU Delft Marketing and Consumer Research); Lloyd, P.A. (TU Delft Methodologie en Organisatie van Design)","Maier, A. (editor)","2021","The formulation of questions in processes of design is an activity affected by cognitive biases inherent to humans. Cognitive biases, developed through gaining experience, influence how decisions are made during problem solving. When an outcome is predictable, experience provides mental shortcuts or heuristics to enable the problem solver to act effectively. When an outcome is uncertain, cognitive biases can wrongfully project preconceptions, elevate self-interest, and undermine the problem solver’s greater ambitions for positive impact. Mitigating cognitive bias is thus vital for design problem solving under conditions of uncertainty. Designers explore uncertainty through an approach typified by human empathy, problem framing, and creativity. This chapter reveals the nature of asking effective questions within designerly thinking. This means understanding nuances of context, surfacing novel insights about how a system performs, and crucially working out how people within systems experience the world around them.","Bias; Complex systems; Designerly thinking; Effective questions; Engineering systems; Engineering systems design; Problem-solution co-evolution","en","book chapter","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Marketing and Consumer Research","","",""
"uuid:151331c8-5fc5-421e-9278-f3555b82f97c","http://resolver.tudelft.nl/uuid:151331c8-5fc5-421e-9278-f3555b82f97c","State-of-the-art review of inherent variability and uncertainty in geotechnical properties and models","","Ching, Jianye (editor); Schweckendiek, T. (editor)","2021","","Geotechnical engineering; Reliability; Uncertainty; Variability","en","book","ISSMGE Technical Committee 304","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:8125ec8e-aa74-44a4-9888-5509c827f50d","http://resolver.tudelft.nl/uuid:8125ec8e-aa74-44a4-9888-5509c827f50d","Atoms of Confusion in Java","Langhout, Chris (Student TU Delft); Aniche, Maurício (TU Delft Software Engineering)","O'Conner, L. (editor)","2021","Although writing code seems trivial at times, problems arise when humans misinterpret what the code actually does. One of the potential causes are ""atoms of confusion"", the smallest possible patterns of misinterpretable source code. Previous research has investigated the impact of atoms of confusion in C code. Results show that developers make significantly more mistakes in code where atoms are present.
In this paper, we replicate the work of Gopstein et al. to the Java language. After deriving a set of atoms of confusion for Java, we perform a two-phase experiment with 132 computer science students (i.e., novice developers).
Our results show that (i) participants are 2.7 up to 56 times more likely to make mistakes in code snippets affected by 7 out of the 14 studied atoms of confusion, and (2) when faced with both versions of the code snippets, participants perceived the version affected by the atom of confusion to be more confusing and/or less readable in 10 out of the 14 studied atoms of confusion.","atoms of confusion; empirical software engineering; program comprehension; software engineering","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Software Engineering","","",""
"uuid:c655ba14-0669-49d0-aadb-7649ca427e5a","http://resolver.tudelft.nl/uuid:c655ba14-0669-49d0-aadb-7649ca427e5a","Building with Nature as a cross-disciplinary approach: The role of hybrid contributions","van Bergen, J. (TU Delft Landscape Architecture); Nijhuis, S. (TU Delft Landscape Architecture); Brand, A.D. (TU Delft Projects); Hertogh, M.J.C.M. (TU Delft Integral Design & Management)","","2021","The incentive for this publication was to expand the realm of enquiry around the topic of Building with Nature (BwN), for two main reasons. First to gain an interdisciplinary, and therefore deeper, understanding of BwN as an object of study. Secondly, but no less important, is an understanding of how different forms of knowledge contribute to our learning regarding BwN. When we understand the contribution of several academic disciplines and knowledge from practice, we may eventually get to the point where we can identify how they can collaborate successfully to contribute to BwN as an interdisciplinary field.","Reflection; BwN; Building with Nature; nature-based solutions; coastal protection; adaptive planning and design; water managemen; natural processes; delta landscapes; ecological hydraulic engineering","en","journal article","","","","","","Vol. 7 (2021): Building with Nature perspectives: Cross-disciplinary BwN approaches in coastal regions. ISBN 978-94-6366-379-3","","","","","Landscape Architecture","","",""
"uuid:bdfb4f6e-ce37-471c-83aa-eb02cbfa5554","http://resolver.tudelft.nl/uuid:bdfb4f6e-ce37-471c-83aa-eb02cbfa5554","Editorial: Building with Nature perspectives","van Bergen, J. (TU Delft Landscape Architecture); Nijhuis, S. (TU Delft Landscape Architecture); Brand, A.D. (TU Delft Projects); Hertogh, M.J.C.M. (TU Delft Integral Design & Management)","","2021","This publication offers an overview of the latest cross-disciplinary developments in the field of Building with Nature (BwN) for the protection of coastal regions. The key philosophy of BwN is the employment of natural processes to serve societal goals, such as flood safety. The starting point is a systems-based approach, making interventions that employ the shaping forces of the natural system to perform measures by self-regulation. Initial pilots of this innovative approach originate from coastal engineering, with the Sand Motor along the coast of South Holland as one of the prime examples. From here, the BwN approach has evolved into a new generation of nature-based hydraulic solutions, such as mangrove forests, coastal reefs, and green dikes.","BwN; building with nature; Nature-based solutions; coastal protection; adaptive planning and design; Water management; natural processes; delta landscapes; ecological hydraulic engineering","en","contribution to periodical","","","","","","Vol. 7 (2021): Building with Nature perspectives: Cross-disciplinary BwN approaches in coastal regions. ISBN 978-94-6366-379-3","","","","","Landscape Architecture","","",""
"uuid:3ca04132-9156-4777-94c3-9b2d9c985029","http://resolver.tudelft.nl/uuid:3ca04132-9156-4777-94c3-9b2d9c985029","Systematic Mapping Study on the Machine Learning Lifecycle","Xie, Yuanhao (ING); Cruz, Luis (TU Delft Software Engineering); Heck, Petra (Fontys ICT); Rellermeyer, Jan S. (TU Delft Dataintensive Systems)","O'Conner, L. (editor)","2021","The development of artificial intelligence (AI) has made various industries eager to explore the benefits of AI. There is an increasing amount of research surrounding AI, most of which is centred on the development of new AI algorithms and techniques. However, the advent of AI is bringing an increasing set of practical problems related to AI model lifecycle management that need to be investigated. We address this gap by conducting a systematic mapping study on the lifecycle of AI model. Through quantitative research, we provide an overview of the field, identify research opportunities, and provide suggestions for future research. Our study yields 405 publications published from 2005 to 2020, mapped in 5 different main research topics, and 31 sub-topics. We observe that only a minority of publications focus on data management and model production problems, and that more studies should address the AI lifecycle from a holistic perspective.","AI lifecycle management; Artificial Intelligence; Software Engineering; Systematic mapping study","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-01-08","","","Software Engineering","","",""
"uuid:4470f6e1-6e3b-4112-86a3-dbe9a421aec3","http://resolver.tudelft.nl/uuid:4470f6e1-6e3b-4112-86a3-dbe9a421aec3","Data-Driven Extract Method Recommendations: A Study at ING","van der Leij, David (Student TU Delft; ING); Binda, J.R. (ING); van Dalen, Robbert (ING); Vallen, Pieter (ING); Luo, Yaping (Eindhoven University of Technology; ING); Aniche, Maurício (TU Delft Software Engineering)","Spinellis, Diomidis (editor)","2021","The sound identification of refactoring opportunities is still an open problem in software engineering. Recent studies have shown the effectiveness of machine learning models in recommending methods that should undergo different refactoring operations. In this work, we experiment with such approaches to identify methods that should undergo an Extract Method refactoring, in the context of ING, a large financial organization. More specifically, we (i) compare the code metrics distributions, which are used as features by the models, between open-source and ING systems, (ii) measure the accuracy of different machine learning models in recommending Extract Method refactorings, (iii) compare the recommendations given by the models with the opinions of ING experts. Our results show that the feature distributions of ING systems and open-source systems are somewhat different, that machine learning models can recommend Extract Method refactorings with high accuracy, and that experts tend to agree with most of the recommendations of the model.","Machine Learning for Software Engineering; Software Engineering; Software Refactoring","en","conference paper","","","","","","","","","","","Software Engineering","","",""
"uuid:462fb222-85ed-4b71-baf7-3ae9c2f69342","http://resolver.tudelft.nl/uuid:462fb222-85ed-4b71-baf7-3ae9c2f69342","Logging Practices with Mobile Analytics: An Empirical Study on Firebase","Harty, Julian (The Open University); Zhang, Haonan (Concordia University); Wei, Lili (The Hong Kong University of Science and Technology); Pascarella, L. (Università della Svizzera Italiana); Aniche, Maurício (TU Delft Software Engineering); Shang, Weiyi (Concordia University)","O'Conner, L. (editor)","2021","Software logs are of great value in both industrial and open-source projects. Mobile analytics logging enables developers to collect logs remotely from their apps running on end user devices at the cost of recording and transmitting logs across the Internet to a centralised infrastructure.This paper makes a first step in characterising logging practices with a widely adopted mobile analytics logging library, namely Firebase Analytics. We provide an empirical evaluation of the use of Firebase Analytics in 57 open-source Android applications by studying the evolution of code-bases to understand: a) the needs-in-common that push practitioners to adopt logging practices on mobile devices, and b) the differences in the ways developers use local and remote logging.Our results indicate mobile analytics logs are less pervasive and less maintained than traditional logging code. Based on our analysis, we believe logging using mobile analytics is more user centered compared to traditional logging, where the latter is mainly used to record information for debugging purposes.","empirical software engineering; logging engineering; mobile analytics; mobile software development; software monitoring","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Software Engineering","","",""
"uuid:d72dd34f-12dc-4546-9c59-3e9528163536","http://resolver.tudelft.nl/uuid:d72dd34f-12dc-4546-9c59-3e9528163536","AI lifecycle models need to be revised: An exploratory study in Fintech","Haakman, Mark (ING); Cruz, Luis (TU Delft Software Engineering); Huijgens, H.K.M. (ING); van Deursen, A. (TU Delft Software Technology)","","2021","Tech-leading organizations are embracing the forthcoming artificial intelligence revolution. Intelligent systems are replacing and cooperating with traditional software components. Thus, the same development processes and standards in software engineering ought to be complied in artificial intelligence systems. This study aims to understand the processes by which artificial intelligence-based systems are developed and how state-of-the-art lifecycle models fit the current needs of the industry. We conducted an exploratory case study at ING, a global bank with a strong European base. We interviewed 17 people with different roles and from different departments within the organization. We have found that the following stages have been overlooked by previous lifecycle models: data collection, feasibility study, documentation, model monitoring, and model risk assessment. Our work shows that the real challenges of applying Machine Learning go much beyond sophisticated learning algorithms – more focus is needed on the entire lifecycle. In particular, regardless of the existing development tools for Machine Learning, we observe that they are still not meeting the particularities of this field.","AI Engineering; AI lifecycle; SE4AI; Machine Learning; Case Study; Case study; AI engineering; Machine learning","en","journal article","","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:dddf4c7c-4a9c-46fe-926e-836e2bc9dbc7","http://resolver.tudelft.nl/uuid:dddf4c7c-4a9c-46fe-926e-836e2bc9dbc7","Experience Report on Soft and Project Skills Building through Repetition","Devroey, Xavier (TU Delft Software Engineering); Amrani, Moussa (University of Namur); Vanderose, Benoît (University of Namur)","Vescan, Andreea (editor); Serban, Camelia (editor); Henry, Julie (editor); Praphamontripong, Upsorn (editor)","2021","Acquiring soft and project skills during their studies is of paramount importance for computer science students to integrate large development teams after graduating. Project-oriented learning offers interesting opportunities for teachers to tutor students, and allows them to acquire and train those skills in addition to the core topics of the course. However, since most existing curricula require courses to be as independent as possible (for organizational reasons for instance), some topics are covered in different courses in slightly different ways. This repetition is interesting for understanding difficult notions appropriately, but may also hamper students' understanding when closely related concepts are embedded in different ways. We report here on our teaching approach: we propose a series of projects that share a common theme, in order to (i) provide a transversal understanding of common notions seen in separate courses, and (ii) introduce soft and project skills in a progressive way, enabling students to iteratively experience and learn skills that are necessary for professional life. We report on the results of interviews conducted with the students and extract valuable lessons for reproducing this approach in different curricula.","project skills; soft skills; software engineering education","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Software Engineering","","",""
"uuid:800ce38b-e77e-4562-b03a-4399a3ebbf36","http://resolver.tudelft.nl/uuid:800ce38b-e77e-4562-b03a-4399a3ebbf36","Evolutionary engineering reveals amino acid substitutions in Ato2 and Ato3 that allow improved growth of Saccharomyces cerevisiae on lactic acid","Baldi, N. (TU Delft BT/Industriele Microbiologie); de Valk, S.C. (TU Delft BT/Industriele Microbiologie); Sousa-Silva, Maria (University of Minho); Casal, Margarida (University of Minho); Soares-Silva, Isabel (University of Minho); Mans, R. (TU Delft BT/Industriele Microbiologie)","","2021","In Saccharomyces cerevisiae, the complete set of proteins involved in transport of lactic acid across the cell membrane has not been determined. In this study, we aimed to identify transport proteins not previously described to be involved in lactic acid transport via a combination of directed evolution, whole-genome resequencing and reverse engineering. Evolution of a strain lacking all known lactic acid transporters on lactate led to the discovery of mutated Ato2 and Ato3 as two novel lactic acid transport proteins. When compared to previously identified S. cerevisiae genes involved in lactic acid transport, expression of ATO3T284C was able to facilitate the highest growth rate (0.15 ± 0.01 h-1) on this carbon source. A comparison between (evolved) sequences and 3D models of the transport proteins showed that most of the identified mutations resulted in a widening of the narrowest hydrophobic constriction of the anion channel. We hypothesize that this observation, sometimes in combination with an increased binding affinity of lactic acid to the sites adjacent to this constriction, are responsible for the improved lactic acid transport in the evolved proteins.","carboxylic acids; evolutionary engineering; protein structure; reverse engineering; transport","en","journal article","","","","","","Accepted Author Manuscript","","2022-05-27","","","BT/Industriele Microbiologie","","",""
"uuid:b27927c9-7d50-4dfe-a750-59fe19920961","http://resolver.tudelft.nl/uuid:b27927c9-7d50-4dfe-a750-59fe19920961","Achieving a quantum smart workforce","Aiello, Clarice D. (University of California); Awschalom, D. D. (University of Chicago; Argonne National Laboratory); Bernien, Hannes (University of Chicago); Brower, Tina (Howard University); Brown, Kenneth R. (Duke University); Ross, R. S. (HRL Laboratories); Singh, M. (Colorado School of Mines); Steuerman, David W. (Kavli Foundation); Thijssen, J.M. (TU Delft QN/Thijssen Group; Kavli institute of nanoscience Delft)","","2021","Interest in building dedicated quantum information science and engineering (QISE) education programs has greatly expanded in recent years. These programs are inherently convergent, complex, often resource intensive and likely require collaboration with a broad variety of stakeholders. In order to address this combination of challenges, we have captured ideas from many members in the community. This manuscript not only addresses policy makers and funding agencies (both public and private and from the regional to the international level) but also contains needs identified by industry leaders and discusses the difficulties inherent in creating an inclusive QISE curriculum. We report on the status of eighteen post-secondary education programs in QISE and provide guidance for building new programs. Lastly, we encourage the development of a comprehensive strategic plan for quantum education and workforce development as a means to make the most of the ongoing substantial investments being made in QISE.","Education; Quantum engineering; Quantum information science; Workforce development","en","review","","","","","","","","","","","QN/Thijssen Group","","",""
"uuid:583f3d2b-a77f-4744-84bf-94f8c6fe180e","http://resolver.tudelft.nl/uuid:583f3d2b-a77f-4744-84bf-94f8c6fe180e","Observed Changes of a Mega Feeder Nourishment in a Coastal Cell: Five Years of Sand Engine Morphodynamics","Roest, Lambertus W.M. (TU Delft Coastal Engineering; Katholieke Universiteit Leuven); de Vries, S. (TU Delft Coastal Engineering); de Schipper, M.A. (TU Delft Coastal Engineering); Aarninkhof, S.G.J. (TU Delft Hydraulic Engineering)","","2021","Recently, mega feeder nourishments have been proposed as a new strategy to nourish sediment-starving beaches. This strategy involves the placement of a large, concentrated sediment volume at a single location along the coast. Wind, waves and currents act as the natural agents to spread the sediment alongshore over the course of years to decades. This article presents the morphological development of the first full-scale implementation of this strategy, examining the 20 × 106 m3“Sand Engine” feeder nourishment and its impact on adjacent coastal sections. The analysis is based on 37 high-resolution topographical surveys, executed in a 17 km coastal cell. These unique data describe the alongshore spreading in the first five years and the response at different elevations of the coastal profile. The analysis shows rapid transformation of the nourishment’s planform shape, changing rapidly into a smooth (Gaussian-like) shape which is gradually extending alongshore over time. Within five years, sediment has been distributed to a 5.8 km stretch of coast from the initial 2.2 km peninsula footprint. Changes in cross-shore and alongshore extent varied strongly over depth, with the strongest morphological response at the mean sea level (MSL) isobath and limited morphodynamic activity at deeper water, below −8 m MSL. This depth-dependent response has resulted in decreasing subtidal slopes in eroding areas, accretive areas contrastingly show a slope increment. These results yield important insights in nourished sediment mobility at different depths near the coast and distribution over a larger coastal cell. However, this single-design assessment cannot address the wide range of mega nourishment design parameters essential for morphological development of its coastal cell. This work suggests limiting cross-shore extent, since it is uncertain whether nourished sediment at deeper water will become active in the coastal system. A continuation of the current monitoring and future research might shed more light on this.","Cross-shore adjustment; Feeder nourishment; Mega nourishment; Nourishment design; Sand engine","en","journal article","","","","","","","","","","Hydraulic Engineering","Coastal Engineering","","",""
"uuid:15fe3466-7314-4d75-aa44-7778f2ba48d9","http://resolver.tudelft.nl/uuid:15fe3466-7314-4d75-aa44-7778f2ba48d9","Ethics education for engineers, creating open educational materials","Borghuis, V. A.J. (Eindhoven University of Technology); Veraart, R. (Wageningen University & Research); Marin, L. (TU Delft Ethics & Philosophy of Technology)","Heiss, Hans-Ulrich (editor); Jarvinen, Hannu-Matti (editor); Mayer, Annette (editor); Schulz, Alexandra (editor)","2021","We propose a workshop on creating Open Educational Materials for teaching ethics to engineering students, based on a project encouraging the reuse, creation and open publication of Case-Based Exercises within a community of ethics and philosophy of technology scholars in the Netherlands.","Engineering students; Ethics education; Open educational materials; Toolkit","en","conference paper","European Society for Engineering Education (SEFI)","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:dff09f59-39d7-4cbf-85d8-53d9649cacfc","http://resolver.tudelft.nl/uuid:dff09f59-39d7-4cbf-85d8-53d9649cacfc","The Relations between Ethical Reasoning and Moral Intuitions among Engineering Students in China","Clancy III, R.F. (TU Delft Ethics & Philosophy of Technology)","","2021","Empirical research in engineering ethics has tended to assess the ethical reasoning abilities of students in predominately WEIRD (Western Educated Industrialized Rich Democratic) countries. However, it is not clear that ethical judgments or behaviors are exclusively or primarily the result of ethical reasoning, or that conclusions based on WEIRD samples would be true of different populations. To address these issues, a study was conducted examining 1. the relation between ethical reasoning and moral intuitions among engineering students in China, and 2. the effects of ethics education on ethical reasoning and moral intuitions. To do so, engineering students at a US-Chinese educational institute in Shanghai, China completed the ESIT (Engineering and Science Issues Test) and MFQ (Moral Foundations Questionnaire) before and after a course on global engineering ethics. The ESIT uses two measures of ethical reasoning: The P score assesses the prevalence of postconventional reasoning, while the N2 score measures the amount of postconventional relative to preconventional reasoning. The MFQ assesses moral intuitions through the importance participants place on care, fairness, authority, loyalty, and sanctity in answering questions about right and wrong, and their relative levels of agreement regarding numerous statements with moral contents. Results indicate that 1. ethical reasoning is positively related to an emphasis on care and fairness 2. ethics education results in significantly higher levels of ethical reasoning, as well as a greater concern with fairness and loyalty. The educational and professional implications of these results are discussed, as well as shortcomings of the current study and directions for future work.","(Global) engineering ethics; China; Cross-cultural; Ethical reasoning; Moral foundations theory; Non-WEIRD","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:5640959a-52c3-4b29-8cde-1b8916ab0759","http://resolver.tudelft.nl/uuid:5640959a-52c3-4b29-8cde-1b8916ab0759","Multi-objective Test Case Selection Through Linkage Learning-Based Crossover","Olsthoorn, Mitchell (TU Delft Software Engineering); Panichella, A. (TU Delft Software Engineering)","O'Reilly, Una-May (editor); Devroey, Xavier (editor)","2021","Test Case Selection (TCS) aims to select a subset of the test suite to run for regression testing. The selection is typically based on past coverage and execution cost data. Researchers have successfully used multi-objective evolutionary algorithms (MOEAs), such as NSGA-II and its variants, to solve this problem. These MOEAs use traditional crossover operators to create new candidate solutions through genetic recombination. Recent studies in numerical optimization have shown that better recombinations can be made using machine learning, in particular linkage learning. Inspired by these recent advances in this field, we propose a new variant of NSGA-II, called L2-NSGA, that uses linkage learning to optimize test case selection. In particular, we use an unsupervised clustering algorithm to infer promising patterns among the solutions (subset of test suites). Then, these patterns are used in the next iterations of L2-NSGA to create solutions that preserve these inferred patterns. Our results show that our customizations make NSGA-II more effective for test case selection. The test suite sub-sets generated by L2-NSGA are less expensive and detect more faults than those generated by MOEAs used in the literature for regression testing.","Multi-objective optimization; Regression testing; Search-based software engineering; Test case selection","en","conference paper","","","","","","","","2022-09-01","","","Software Engineering","","",""
"uuid:b5eece97-0427-4415-aa21-0900183ae116","http://resolver.tudelft.nl/uuid:b5eece97-0427-4415-aa21-0900183ae116","A Systematic Comparison of Search-Based Approaches for LDA Hyperparameter Tuning","Panichella, A. (TU Delft Software Engineering)","","2021","Context: Latent Dirichlet Allocation (LDA) has been successfully used in the literature to extract topics from software documents and support developers in various software engineering tasks. While LDA has been mostly used with default settings, previous studies showed that default hyperparameter values generate sub-optimal topics from software documents. Objective: Recent studies applied meta-heuristic search (mostly evolutionary algorithms) to configure LDA in an unsupervised and automated fashion. However, previous work advocated for different meta-heuristics and surrogate metrics to optimize. The objective of this paper is to shed light on the influence of these two factors when tuning LDA for SE tasks. Method: We empirically evaluated and compared seven state-of-the-art meta-heuristics and three alternative surrogate metrics (i.e., fitness functions) to solve the problem of identifying duplicate bug reports with LDA. The benchmark consists of ten real-world and open-source projects from the Bench4BL} dataset. Results: Our results indicate that (1) meta-heuristics are mostly comparable to one another (except for random search and CMA-ES), and (2) the choice of the surrogate metric impacts the quality of the generated topics and the tuning overhead. Furthermore, calibrating LDA helps identify twice as many duplicates than untuned LDA when inspecting the top five past similar reports. Conclusion: No meta-heuristic and/or fitness function outperforms all the others, as advocated in prior studies. However, we can make recommendations for some combinations of meta-heuristics and fitness functions over others for practical use. Future work should focus on improving the surrogate metrics used to calibrate/tune LDA in an unsupervised fashion","Duplicate bug report; Hyperparameter optimization; Latent dirichlet allocation; Metaheuristic search; Search-based software engineering; Topic modeling","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:6e328f45-bfba-4bad-92f4-37fa9e74f3ab","http://resolver.tudelft.nl/uuid:6e328f45-bfba-4bad-92f4-37fa9e74f3ab","Interactive Black-Hole Visualization","Verbraeck, A.W. (TU Delft Computer Graphics and Visualisation); Eisemann, E. (TU Delft Computer Graphics and Visualisation)","","2021","We present an efficient algorithm for visualizing the effect of black holes on its distant surroundings as seen from an observer nearby in orbit. Our solution is GPU-based and builds upon a two-step approach, where we first derive an adaptive grid to map the 360-view around the observer to the distorted celestial sky, which can be directly reused for different camera orientations. Using a grid, we can rapidly trace rays back to the observer through the distorted spacetime, avoiding the heavy workload of standard tracing solutions at real-time rates. By using a novel interpolation technique we can also simulate an observer path by smoothly transitioning between multiple grids. Our approach accepts real star catalogues and environment maps of the celestial sky and generates the resulting black-hole deformations in real time.","Physical & Environmental Sciences; Engineering; Mathematics; Computer Graphics Techniques; Algorithms","en","journal article","","","","","","Accepted Author Manuscript","","","","","Computer Graphics and Visualisation","","",""
"uuid:af74b4d6-e828-4368-9c86-2d3d39bac94c","http://resolver.tudelft.nl/uuid:af74b4d6-e828-4368-9c86-2d3d39bac94c","Search-Based Software Re-Modularization: A Case Study at Adyen","Schröder, C.J. (Adyen B.V.); van der Feltz, Adriaan (Adyen B.V.); Panichella, A. (TU Delft Software Engineering); Aniche, Maurício (TU Delft Software Engineering)","O'Conner, L. (editor)","2021","Deciding what constitutes a single module, what classes belong to which module or the right set of modules for a specific software system has always been a challenging task. The problem is even harder in large-scale software systems composed of thousands of classes and hundreds of modules. Over the years, researchers have been proposing different techniques to support developers in re-modularizing their software systems. In particular, the search-based software re-modularization is an active research topic within the software engineering community for more than 20 years.
This paper describes our efforts in applying search-based software re-modularization approaches at Adyen, a large-scale payment company. Adyen's code base has 5.5M+ lines of code, split into around 70 different modules. We leveraged the existing body of knowledge in the field to devise our own search algorithm and applied it to our code base. Our results show that search-based approaches scale to large code bases as ours. Our algorithm can find solutions that improve the code base according to the metrics we optimize for, and developers see value in the recommendations. Based on our experiences, we then list a set of challenges and opportunities for future researchers, aiming at making search-based software re-modularization more efficient for large-scale software companies.","software engineering; search-based software engineering; software refactoring; software modularization","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Software Engineering","","",""
"uuid:4765f1b6-fdf1-4def-89af-2e3669c686fe","http://resolver.tudelft.nl/uuid:4765f1b6-fdf1-4def-89af-2e3669c686fe","Automatically Identifying Parameter Constraints in Complex Web APIs: A Case Study at Adyen","Grent, Henk (Adyen B.V.); Akimov, Aleksei (Adyen B.V.); Aniche, Maurício (TU Delft Software Engineering)","O'Conner, L. (editor)","2021","Web APIs may have constraints on parameters, such that not all parameters are either always required or always optional. Moreover, the presence or value of one parameter could cause another parameter to be required, or parameters could have restrictions on what kinds of values are valid. Having a clear overview of the constraints helps API consumers to integrate without the need for additional support and with fewer integration faults. We made use of existing documentation and code analysis approaches for identifying parameter constraints in complex web APIs. In this paper, we report our case study of several APIs at Adyen, a large-scale payment company that offers complex Web APIs to its customers. Our results show that the documentation- and code-based approach can identify 23% and 53% of the constraints respectively and, when combined, 68% of them. We also reflect on the current challenges that these approaches face. In particular, the absence of information that explicitly describes the constraints in the documentation (in the documentation analysis), and the engineering of a sound static code analyser that is sensitive to data-flow, maintains longer parameter references throughout the API's code, and that is able to symbolically execute the several libraries and frameworks used by the API (in the static analysis).","Parameter constraints inference; Software engineering; Web apis","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Software Engineering","","",""
"uuid:0bc0b71f-3b1c-442b-bc35-fc92397c3aee","http://resolver.tudelft.nl/uuid:0bc0b71f-3b1c-442b-bc35-fc92397c3aee","Game Engine-based Point Cloud Visualization and Perception for Situation Awareness of Crisis Indoor Environments","Liu, Zhenyu (Student TU Delft); Fu, Runnan (Student TU Delft); Wang, Linjun (Student TU Delft); Jin, Yuzhen (Student TU Delft); Papakostas, Theodoros (Student TU Delft); Mainelli, Xenia Una (Student TU Delft); Voûte, R.L. (TU Delft GIS Technologie; CGI Nederland B.V); Verbree, E. (TU Delft GIS Technologie)","Basiri, Anahid (editor); Gartner, Georg Gartner (editor); Huang, Haosheng (editor)","2021","Because unknown interior layouts can have serious consequences in time-sensitive situations, crisis response teams request many potential solutions for visualizing indoor environments in crisis scenarios. This research uses a game engine to directly visualize point cloud data input of indoor environments for generating clear interaction between the environment and viewers, to aid decision-making in high-stress moments. The prospective final product is an integration of game-oriented visualization and cartography, hosted within Unreal Engine 4 (UE4), allowing users to navigate throughout an indoor environment, and customizing certain interaction features. The UE4 project consists of 4 modules: data preprocessing, render style, functional module, and user interface. Finally, this research uses a single-floor indoor point cloud dataset collected from a building in Rotterdam, the Netherlands for the implementation.","Game Engine; Unreal Engine 4; 3D Visualization; Situation Awareness; Point Cloud; Indoor Environment; Crisis Scenario","en","conference paper","TU Wien","","","","","","","","","","GIS Technologie","","",""
"uuid:25972a32-390c-4b90-af8b-1cbfccb6a4b4","http://resolver.tudelft.nl/uuid:25972a32-390c-4b90-af8b-1cbfccb6a4b4","Design of Information-Intensive Systems Involving Cognitive Aspects: An Emerging Opportunity for Transdisciplinary Cooperation","Vroom, R.W. (TU Delft Mechatronic Systems Design); van der Vegte, Wilhelm Frederik (TU Delft Internet of Things)","Blessing, Lucienne (editor); Qureshi, Ahmed Jawad (editor); Gericke, Kilian (editor)","2021","With the rise of smart systems, ubiquitous computing and cyber-physical systems, information-intensiveness of products increases and users become challenged—possibly even overloaded—with expanding options and possible interactions. The number of possible variations of user-operation sequences can rapidly escalate and for designers it becomes difficult to foresee all possible outcomes,which might include unacceptable performance, failure, and even fatalities.With the objective to reduce the risk of unwanted cognitive effects and to realize a more symbiotic relationship between users and systems, we showhowtwo model-based theories from cognitive science, i.e., cognitive architectures and mental models, can be deployed in the design of these systems.We argue that the deployment of such models requires a transdisciplinary approach in which designers intensively cooperate with cognitive scientists and end users.","Cognitive engineering; Information-intensive systems; Mental models; Cognitive architectures; Transdisciplinary cooperation","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-07-05","","","Mechatronic Systems Design","","",""
"uuid:043c3099-b61a-41aa-8469-998854766824","http://resolver.tudelft.nl/uuid:043c3099-b61a-41aa-8469-998854766824","Development and Piezoelectric Properties of a Stack Units-Based Piezoelectric Device for Roadway Application","Li, Chenchen (Tongji University; Rheinisch-Westfälische Technische Hochschule); Yang, Fan (Tongji University); Liu, Pengfei (Rheinisch-Westfälische Technische Hochschule); Fu, Chaoliang (Rheinisch-Westfälische Technische Hochschule); Liu, Quan (Rheinisch-Westfälische Technische Hochschule); Zhao, Hongduo (Tongji University); Lin, P. (TU Delft Pavement Engineering)","","2021","To improve the energy harvesting efficiency of the piezoelectric device, a stack units-based structure was developed and verified. Factors such as stress distribution, load resistance, loads, and loading times influencing the piezoelectric properties were investigated using theoretical analysis and experimental tests. The results show that the unit number has a negative relationship with the generated energy and the stress distribution has no influence on the power generation of the piezoelectric unit array. However, with a small stress difference, units in a parallel connection can obtain high energy conversion efficiency. Additionally, loaded with the matched impedance of 275.0 kΩ at 10.0 kN and 10.0 Hz, the proposed device reached a maximum output power of 84.3 mW, which is enough to supply the low-power sensors. Moreover, the indoor load test illustrates that the electrical performance of the piezoelectric device was positively correlated with the simulated loads when loaded with matched resistance. Furthermore, the electrical property remained stable after the fatigue test of 100,000 cyclic loads. Subsequently, the field study confirmed that the developed piezoelectric device had novel piezoelectric properties with an open-circuit voltage of 190 V under an actual tire load, and the traffic parameters can be extracted from the voltage waveform","pavement engineering; energy harvesting; piezoelectric device; stacked piezoelectric unit; piezoelectric properties; roadway application","en","journal article","","","","","","","","","","","Pavement Engineering","","",""
"uuid:fadaa87f-1530-40a6-b244-25b88dae6b78","http://resolver.tudelft.nl/uuid:fadaa87f-1530-40a6-b244-25b88dae6b78","Tuning electron transfer by crystal facet engineering of BiVO4 for boosting visible-light driven photocatalytic reduction of bromate","Liu, Guoshuai (Jiangnan University); Zhu, Yukun (Qingdao University of Technology); Yan, Qun (Jiangnan University; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment); Wang, Han (Jiangnan University); Wu, Peng (Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment); Shen, Yaoliang (Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment); Doekhi-Bennani, Y. (TU Delft Sanitary Engineering)","","2021","Removal of bromate (BrO3−) has gained increasing attention in drinking water treatment process. Photocatalysis technology is an effective strategy for bromate removal. During the photocatalytic reduction of bromate process, the photo-generated electrons are reductive species toward bromate reduction and photo-generated holes responsible for water oxidation. In this study, the monoclinic bismuth vanadate (BiVO4) single crystal was developed as a visible photocatalyst for the effective removal of bromate. The as-synthesized BiVO4 photocatalyst with optimized {010} and {110} facets ratio could achieve almost 100% removal efficiency of BrO3− driven by visible light with a first-order kinetic constant of 0.0368 min−1. As demonstrated by the electron scavenger experiment and density functional theory (DFT) calculations, the exposed facets of BiVO4 should account for the high photocatalytic reduction efficiency. Under visible light illumination, the photo-generated electron and holes were spatially transferred to {010} facets and {110} facets, respectively. The BiVO4 single crystal photocatalyst may serve as an attractive photocatalyst by virtue of its response to the visible light, spatially charge transfer and separation as well as high photocatalytic activity, which will make the removal of BrO3− in water much easier, more economical and more sustainable.","Bismuth vanadate; Bromate; Crystal engineering; Photocatalysis","en","journal article","","","","","","Accepted Author Manuscript","","2023-01-13","","","Sanitary Engineering","","",""
"uuid:a555168c-f255-4ac0-abb5-e84217fcbff7","http://resolver.tudelft.nl/uuid:a555168c-f255-4ac0-abb5-e84217fcbff7","Traditional vs. Machine-learning methods for forecasting sandy shoreline evolution using historic satellite-derived shorelines","Calkoen, Floris (Deltares; Vrije Universiteit Amsterdam); Luijendijk, Arjen (TU Delft Coastal Engineering; Deltares); Rivero, Cristian Rodriguez (Vrije Universiteit Amsterdam); Kras, Etienne (Deltares); Baart, F. (Deltares)","","2021","Forecasting shoreline evolution for sandy coasts is important for sustainable coastal management, given the present-day increasing anthropogenic pressures and a changing future climate. Here, we evaluate eight different time-series forecasting methods for predicting future shorelines derived from historic satellite-derived shorelines. Analyzing more than 37,000 transects around the globe, we find that traditional forecast methods altogether with some of the evaluated probabilistic Machine Learning (ML) time-series forecast algorithms, outperform Ordinary Least Squares (OLS) predictions for the majority of the sites. When forecasting seven years ahead, we find that these algorithms generate better predictions than OLS for 54% of the transect sites, producing forecasts with, on average, 29% smaller Mean Squared Error (MSE). Importantly, this advantage is shown to exist over all considered forecast horizons, i.e., from 1 up to 11 years. Although the ML algorithms do not produce significantly better predictions than traditional time-series forecast methods, some proved to be significantly more efficient in terms of computation time. We further provide insight in how these ML algorithms can be improved so that they can be expected to outperform not only OLS regression, but also the traditional time-series forecast methods. These forecasting algorithms can be used by coastal engineers, managers, and scientists to generate future shoreline prediction at a global level and derive conclusions thereof.","Coastal engineering; Coastal oceanography; Data science; Deep learning; Forecasting shorelines; Machine learning; Sandy beaches; Shoreline-trajectories; Time-series forecasting","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:48629f4b-6d84-4dc9-ace5-85f889b77f81","http://resolver.tudelft.nl/uuid:48629f4b-6d84-4dc9-ace5-85f889b77f81","Workshop on open-access educational materials","Marin, L. (TU Delft Ethics & Philosophy of Technology); Borghuis, Tijn (Eindhoven University of Technology); Veraart, Roel (Wageningen University & Research); Naik, Tanishi (University of Waterloo)","Caron, Brandiff (editor); Schmitt, Ketra A. (editor); Pearl, Zach (editor); Dara, Rozita (editor); Love, Heather A. (editor)","2021","This workshop is targeted at anyone interested in teaching ethics to engineering students. It aims to introduce the participants to the 4TU. Centre for Ethics and Technology method of building up Case-Based Exercises by having them apply it to create a Case-Based Exercise of their own. Participants will work in small groups (break-out rooms), where each group will be asked to start building a Case-Based Exercise intended to be taught in an ethics/philosophy of technology course for engineering students using the toolkit.","case-based learning; Education; engineering; ethics; open-access; pedagogy","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-07-06","","","Ethics & Philosophy of Technology","","",""
"uuid:41314da3-336d-4627-abab-00453d5ba7af","http://resolver.tudelft.nl/uuid:41314da3-336d-4627-abab-00453d5ba7af","Teaching buckling of cylindrical shells through an effective laboratory demonstration","Gavioli, M. (TU Delft Aerospace Structures & Computational Mechanics); Bisagni, C. (TU Delft Aerospace Structures & Computational Mechanics)","","2021","A laboratory demonstration for a Stability of Structures course is presented, consisting in the buckling test of two cylindrical shells: a 3 D-printed and a composite cylinder. The learning outcomes have been formulated by comparing what can be learnt from theoretical lessons and buckling tests. The activity follows the Interactive Lecture Demonstration approach. Main results show that the activity helped students’ understanding of shell buckling and it increased their enthusiasm for the topic. This demonstration is easily implementable, and the presented step-by-step development methodology provides guidelines to develop similar activities for different engineering subjects.","engineering education; intended learning outcomes; pedagogical affordance; Shell buckling; structural stability","en","journal article","","","","","","","","","","","Aerospace Structures & Computational Mechanics","","",""
"uuid:eb1f57a4-a89f-4fbe-a887-07b0f2441b5e","http://resolver.tudelft.nl/uuid:eb1f57a4-a89f-4fbe-a887-07b0f2441b5e","Engineering Roles in Building with Nature Interdisciplinary Design: Educational Experiences","Klaassen, R.G. (TU Delft Teaching & Learning Services; 4TU.Centre for Engineering Education); Kothuis, B.L.M. (TU Delft Hydraulic Structures and Flood Risk); Slinger, J (TU Delft Policy Analysis; Rhodes University)","","2021","Building with Nature (BwN) infrastructure designs are characterised by disciplinary integration, non-linearity, diverse and fluid design requirements, and long-term time frames that balance the limitations of earth’s natural systems and the socio-technical systems created by humans. Differentiating roles in the engineering design process may offer strategies for better solutions. Four complementary engineering design roles were distinguished, namely: Specialists, System Integrators, Front-end Innovators, and Contextual Engineers. The key research question addressed in this paper asks, how can the introduction of engineering roles enhance interdisciplinary processes for BwN design? Three Building with Nature design workshops with international groups of students from multiple disciplines and various education levels provided the ideal context for investigating whether engineering roles enhance such interdisciplinary ways of working. Results indicate that the application of engineering roles in each of the three workshops indeed supported interdisciplinary design. A number of conditions for successful implementation within an authentic learning environment could be identified. The engineering roles sustain an early, divergent way of looking at the design problem and support the search for common ground across the diverse perspectives of the team members, each bringing different disciplinary backgrounds to the design table. The chapter closes with a discussion on the value of engineering design roles and their significance for the Building with Nature approach.","Interdisciplinary Education; Engineering Roles; Buidling with Nature; Engineering education","en","journal article","","","","","","","","","","","Teaching & Learning Services","","",""
"uuid:5f86a024-4935-4574-b162-0c1cb9cf0976","http://resolver.tudelft.nl/uuid:5f86a024-4935-4574-b162-0c1cb9cf0976","Game theoretic lane change strategy for cooperative vehicles under perfect information","Ladino, Andres (COSYS); Wang, M. (TU Delft Transport and Planning)","Li, Ruimin (editor); He, Zhengbing (editor)","2021","Lane change maneuvers are main causes of traffic turbulence at highway bottlenecks. We propose a dynamic game framework to derive the system optimum strategy for a network of cooperative vehicles interacting at a merging bottleneck. Cooperative vehicles on the highway mainline seek for optimal strategies (i.e., whether and when to perform courtesy lane change to facilitate the merging vehicle) to minimize their cost, while taking into account potential future interactions at the merging section while minimizing the distance traveled on the acceleration lane. An optimal strategy is found by minimizing the joint cost of all interacting vehicles while respecting behavioral and physical constraints. Numerical examples show the feasibility of the approach in capturing the nature of conflict and cooperation during the merging process, and demonstrate the benefits of sharing information and cooperative control for connected and automated vehicles.","road traffic control; roads; road vehicles; game theory; road safety; road traffic; traffic engineering computing","en","book chapter","Institution of Engineering and Technology","","","","","","","","","","Transport and Planning","","",""
"uuid:eff4e78f-4323-4ba1-ae60-43cf36257673","http://resolver.tudelft.nl/uuid:eff4e78f-4323-4ba1-ae60-43cf36257673","Hybrid Multi-level Crossover for Unit Test Case Generation","Olsthoorn, Mitchell (TU Delft Software Engineering); Derakhshanfar, P. (TU Delft Software Engineering); Panichella, A. (TU Delft Software Engineering)","O'Reilly, Una-May (editor); Devroey, Xavier (editor)","2021","State-of-the-art search-based approaches for test case generation work at test case level, where tests are represented as sequences of statements. These approaches make use of genetic operators (i.e., mutation and crossover) that create test variants by adding, altering, and removing statements from existing tests. While this encoding schema has been shown to be very effective for many-objective test case generation, the standard crossover operator (single-point) only alters the structure of the test cases but not the input data. In this paper, we argue that changing both the test case structure and the input data is necessary to increase the genetic variation and improve the search process. Hence, we propose a hybrid multi-level crossover (HMX) operator that combines the traditional test-level crossover with data-level recombination. The former evolves and alters the test case structures, while the latter evolves the input data using numeric and string-based recombinational operators. We evaluate our new crossover operator by performing an empirical study on more than 100 classes selected from open-source Java libraries for numerical operations and string manipulation. We compare HMX with the single-point crossover that is used in EvoSuite w.r.t structural coverage and fault detection capability. Our results show that HMX achieves a statistically significant increase in 30% of the classes up to 19% in structural coverage compared to the single-point crossover. Moreover, the fault detection capability improved up to 12% measured using strong mutation score.","Crossover operator; Empirical software engineering; Search-based software testing; Test case generation","en","conference paper","","","","","","","","","","","Software Engineering","","",""
"uuid:0f667fd0-bf2d-4d90-a685-5b9956b68ba0","http://resolver.tudelft.nl/uuid:0f667fd0-bf2d-4d90-a685-5b9956b68ba0","Challenges for the utilization of methane as a chemical feedstock","Franz, R.P.M. (TU Delft ChemE/Inorganic Systems Engineering); Uslamin, E. (TU Delft ChemE/Inorganic Systems Engineering; University of Tyumen, Tyumen); Pidko, E.A. (TU Delft ChemE/Algemeen; TU Delft ChemE/Inorganic Systems Engineering)","","2021","The abundance of methane has led to a strong interest to use methane as a feedstock in the chemical industry. One of the main challenges is the initial activation of the methane molecule. This has resulted in the development of several different approaches to utilize methane, some more developed than others. In this work the current status of the different approaches is discussed and the main issues for industrial utilization described. A special focus of this work is the status of catalyst development.","Catalysis engineering; Catalyst deactivation; Dry reforming; Heterogeneous catalysis; Methane activation; Methane halogenation; Methane upgrading; Methanol; Selective oxidation; Steam reforming","en","review","","","","","","","","2023-11-02","","","ChemE/Inorganic Systems Engineering","","",""
"uuid:7e298ebd-799c-4f8a-a312-13d6ebfb90f9","http://resolver.tudelft.nl/uuid:7e298ebd-799c-4f8a-a312-13d6ebfb90f9","Use of fine recycled concrete aggregates in concrete: A critical review","Nedeljković, Marija (TU Delft Materials and Environment; TNO); Visser, Jeanette (TNO); Šavija, B. (TU Delft Materials and Environment); Valcke, Siska (TNO); Schlangen, E. (TU Delft Materials and Environment)","","2021","This paper discusses the state-of-the-art of the fine recycled concrete aggregates (fRCA), focusing on their physical and chemical properties, engineering properties and durability of concretes with fRCA. Based on the systematic review of the published literature, it is impossible to deduce without any further research the guidelines and tools to introduce the widespread application of the fRCA in new concrete whilst keeping the cement contents at least the same or preferably lower. Namely, what is still missing is knowledge on key physico-chemical properties and their relation to the quality of the concrete mix and the concrete performance. This paper sets the foundations for better understanding the quality of fRCA obtained either from parent concrete specifically produced in the laboratory, with controlled crushing and sieving of the recycled aggregates or from field structures. By comparing properties of fRCA with properties of fine natural aggregates, the key limiting properties of fRCA are identified as the high water absorption of fRCA, moisture state of fRCA, agglomeration of particles and adhered mortar. As such, continuous quality of fRCA is hard to be obtained, even though they may be more continuous in terms of chemistry. Advanced characterization techniques and concrete technology tools are needed to account for limiting properties of fRCA in concrete mix design.","Concrete mix design; Durability; Engineering properties; Fine natural aggregates; Fine recycled concrete aggregates; Quality indicators","en","review","","","","","","","","","","","Materials and Environment","","",""
"uuid:eaf7648b-d661-4396-b11d-efdff943f8b9","http://resolver.tudelft.nl/uuid:eaf7648b-d661-4396-b11d-efdff943f8b9","A multinomial process tree for reliability assessment of machinery in autonomous ships","Abaei, M.M. (TU Delft Ship Design, Production and Operations); Hekkenberg, R.G. (TU Delft Ship Design, Production and Operations); BahooToroody, Ahmad (Aalto University)","","2021","Maritime Autonomous Surface Ships have received a significant amount of attention in recent projects. They promise a reduction in marine accidents and mitigation of human errors. Most of the ongoing research effort is directed toward autonomous navigation and cybersecurity. However, the importance of a machinery plant in the engine room that can operate reliably without human attendance is hardly investigated. To prevent failures in such systems and extend the interval between required human interventions, it is essential to improve their reliability. This paper aims to present a systematic approach to evaluate the reliability of an autonomous system under the influence of uncertain disruptions and to predict failure rates of unattended machinery plants. A Multinomial Process Tree is used to model failures in the main failure-sensitive components. Hierarchical Bayesian Inference is adopted to facilitate the prediction of frequencies of disruptive events and estimate the entire system's failure rate. The outcome of this research enables design strategies to improve the reliability of autonomous ships and prevent Fatal Technical Failure during the operation. This allows assessing whether a given machinery plant is sufficiently reliable to be used on unmanned ships. A case study is considered to demonstrate the application of the presented method.","Autonomous shipping; Bayesian inference; Machinery plant; Multinomial process tree; Reliability engineering","en","journal article","","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:a2f9a46b-b42f-4f69-977b-3fdc2afc13a2","http://resolver.tudelft.nl/uuid:a2f9a46b-b42f-4f69-977b-3fdc2afc13a2","Assessing sponge cities performance at city scale using remotely sensed LULC changes: Case study Nanjing","Liu, X. (TU Delft Hydraulic Structures and Flood Risk; Southeast University; IHE Delft Institute for Water Education); Fu, Dafang (Southeast University); Zevenbergen, C. (TU Delft Hydraulic Structures and Flood Risk; TU Delft Urban Design; IHE Delft Institute for Water Education); Busker, Tim (Vrije Universiteit Amsterdam); Yu, Meixiu (Hohai University)","","2021","As a result of high-density urbanization and climate change, both the frequency and intensity of extreme urban rainfall are increasing. Drainage systems are not designed to cope with this increase, and as a result, floods are becoming more common in cities, particularly in the rapidly growing cities of China. To better cope with more frequent and severe urban flooding and to improve the water quality of stormwater runoff, the Chinese government launched the national Sponge City Construction (SCC) program in 2014. The current SCC design standards and guidelines are based on static values (e.g., return periods, rainfall intensities, and volume capture ratio (VCR)). They do not fully acknowledge the large differences in climate conditions across the country and assume that the hydraulic conditions will not change over time. This stationary approach stems from the traditional engineering approach designed for grey infrastructure (following a “one size fits all” approach). The purpose of this study was to develop a methodology to assess the VCR baseline (before construction in the pre-development stage) and changes in VCR (difference between the VCR of the pre-and post-development stage). The VCR of the post-development stage is one of the required indicators of the Assessment Standard for Sponge Cities Effects to evaluate SCC projects. In this study, the VCR was derived from remote-sensing-based land use land cover (LULC) change analysis, applying an unsupervised classification algorithm on different Landsat images from 1985 to 2015. A visualization method (based upon Sankey chart, which depicts the flows and their proportions of components) and a novel and practical partitioning method for built-up regions were developed to visualize and quantify the states and change flows of LULC. On the basis of these findings, we proposed a new indicator, referred to as VCRa − L, in order to assess the changes in urban hydrology after SCC construction. This study employed the city of Nanjing as a case study and analyzed detailed information on how LULC changes over time of built-up areas. The surface area of the urban and built-up areas of Nanjing quadrupled from 11% in 1985 to 44% in 2015. In the same period, neither the entire city nor its subregions reached the VCR target of 80%. The proposed new methodology aims to support national, regional, and city governments to identify and prioritize where to invest and implement SCC measures more effectively in cities across China.","Built-up area partitioning method; Google earth engine; Land use change; Modified Sankey chart; Remote sensing; Sponge city construction; Volume capture ratio","en","journal article","","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:c098bf6f-b04d-4dea-a6c9-7b6bcc6447fb","http://resolver.tudelft.nl/uuid:c098bf6f-b04d-4dea-a6c9-7b6bcc6447fb","Eleven years of mangrove–mudflat dynamics on the mud volcano-induced prograding delta in east java, indonesia: Integrating uav and satellite imagery","Beselly, S.M. (TU Delft Coastal Engineering; IHE Delft Institute for Water Education; Brawijaya University); van der Wegen, Mick (IHE Delft Institute for Water Education; Deltares); Grueters, Uwe (Justus Liebig University Giessen); Reyns, J.A.H. (IHE Delft Institute for Water Education; Deltares); Dijkstra, Jasper (Deltares); Roelvink, D. (TU Delft Coastal Engineering; IHE Delft Institute for Water Education; Deltares)","","2021","This article presents a novel approach to explore mangrove dynamics on a prograding delta by integrating unmanned aerial vehicle (UAV) and satellite imagery. The Porong Delta in Indonesia has a unique geographical setting with rapid delta development and expansion of the mangrove belt. This is due to an unprecedented mud load from the LUSI mud volcanic eruption. The mangrove dynamics analysis combines UAV-based Structure from Motion (SfM) photogrammetry and 11 years (2009–2019) satellite imagery cloud computing analysis by Google Earth Engine (GEE). Our analysis shows unique, high-spatiotemporal-resolution mangrove extent maps. The SfM pho-togrammetry analysis leads to a 3D representation of the mangrove canopy and an estimate of mangrove biophysical properties with accurate height and individual position of the mangroves stand. GEE derived vegetation indices resulted in high (three-monthly) resolution mangrove coverage dynamics over 11 years (2009–2019), yielding a value of more than 98% for the overall, producer and consumer accuracy. Combining the satellite-derived age maps and the UAV-derived spatial tree structure allowed us to monitor the mangrove dynamics on a rapidly prograding delta along with its structural attributes. This analysis is of essential value to ecologists, coastal managers, and poli-cymakers.","Google Earth Engine; Mangroves; Remote sensing; SfM Photogrammetry; UAV","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:6b2bdd67-154a-4e58-b739-fd704c9d57d9","http://resolver.tudelft.nl/uuid:6b2bdd67-154a-4e58-b739-fd704c9d57d9","Engineering heterologous molybdenum-cofactor-biosynthesis and nitrate-assimilation pathways enables nitrate utilization by Saccharomyces cerevisiae","Perli, T. (TU Delft BT/Industriele Microbiologie); van der Vorm, Daan N.A. (Student TU Delft); Wassink, Mats (Student TU Delft); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2021","Metabolic capabilities of cells are not only defined by their repertoire of enzymes and metabolites, but also by availability of enzyme cofactors. The molybdenum cofactor (Moco) is widespread among eukaryotes but absent from the industrial yeast Saccharomyces cerevisiae. No less than 50 Moco-dependent enzymes covering over 30 catalytic activities have been described to date, introduction of a functional Moco synthesis pathway offers interesting options to further broaden the biocatalytic repertoire of S. cerevisiae. In this study, we identified seven Moco biosynthesis genes in the non-conventional yeast Ogataea parapolymorpha by SpyCas9-mediated mutational analysis and expressed them in S. cerevisiae. Functionality of the heterologously expressed Moco biosynthesis pathway in S. cerevisiae was assessed by co-expressing O. parapolymorpha nitrate-assimilation enzymes, including the Moco-dependent nitrate reductase. Following two-weeks of incubation, growth of the engineered S. cerevisiae strain was observed on nitrate as sole nitrogen source. Relative to the rationally engineered strain, the evolved derivatives showed increased copy numbers of the heterologous genes, increased levels of the encoded proteins and a 5-fold higher nitrate-reductase activity in cell extracts. Growth at nM molybdate concentrations was enabled by co-expression of a Chlamydomonas reinhardtii high-affinity molybdate transporter. In serial batch cultures on nitrate-containing medium, a non-engineered S. cerevisiae strain was rapidly outcompeted by the spoilage yeast Brettanomyces bruxellensis. In contrast, an engineered and evolved nitrate-assimilating S. cerevisiae strain persisted during 35 generations of co-cultivation. This result indicates that the ability of engineered strains to use nitrate may be applicable to improve competitiveness of baker's yeast in industrial processes upon contamination with spoilage yeasts.","Metabolic engineering; Molybdenum cofactor; Nitrate assimilation; Nitrate reductase; Saccharomyces cerevisiae","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:8abdbcdc-eb51-43f7-b5db-5a8169d7bdfa","http://resolver.tudelft.nl/uuid:8abdbcdc-eb51-43f7-b5db-5a8169d7bdfa","Accretion-erosion conversion in the subaqueous Yangtze Delta in response to fluvial sediment decline","Luan, Hua Long (East China Normal University; Changjiang River Scientific Research Institute (CRSRI)); Ding, Ping Xing (East China Normal University); Yang, Shi Lun (East China Normal University); Wang, Zhengbing (TU Delft Coastal Engineering; East China Normal University; Deltares)","","2021","Identifying the pattern of delta morphological change under decreasing sediment flux due to dam construction is essential for sustainable management in such densely populated coastal areas. In this study, we investigated the morphological processes of the Yangtze mouth bar and prodelta based on bathymetric data on a decadal-interannual scale (1958, 1978, 1997, 2002, 2007, 2010, 2013 and 2015). We found that strong accretion (205.1 Mm3 yr−1) occurred during 1958–1978, when a high sediment load (465 Mt yr−1) was supplied by the Yangtze. Afterwards, the net accumulation rate decreased to 31.9 Mm3 yr−1 in 1978–1997 and 114.6 Mm3 yr−1 in 1997–2002 as a result of riverine sediment loads decreasing to 390 Mt yr−1 and 314 Mt yr−1, respectively. Surprisingly, the net accumulation rate increased to 130.8 Mm3 yr−1 in 2002–2007, though the sediment load sharply decreased to 177 Mt yr−1. This anomaly was attributed to the construction of training walls within the mouth bar area, which induced significant accretion in groyne-sheltered areas and nearby regions. Along with a further decrease in sediment load, the entire study area converted to net erosion of −200.4 Mm3 yr−1 in 2007–2010 and −152.2 Mm3 yr−1 in 2010–2013. Stronger erosion in the former period was partly caused by intensive dredging activities in the mouth bar area. The critical sediment discharge for the Yangtze mouth bar and prodelta to retain net accretion was estimated to be ca. 218 Mt yr−1. If deducting the impacts of estuarine engineering projects on accretion/erosion during 1997–2010, the critical sediment discharge is adjusted to ca. 234 Mt yr−1. In combination with previously reported accretion-erosion conversion elsewhere in the Yangtze Delta, we inferred that most portion of the subaqueous delta has most likely converted from net accretion to net erosion in response to fluvial sediment decline, and the mouth bar area showed the latest conversion among portions of the delta. Integrated assessment and adaptive strategies are urgently required for the Yangtze Delta to survive the coming erosional stage.","Accretion-erosion conversion; Estuarine engineering projects; Fluvial sediment decline; Yangtze Delta","en","journal article","","","","","","Accepted author manuscript","","2023-03-13","","","Coastal Engineering","","",""
"uuid:468fd021-89bd-4e15-af21-f3d3e3671257","http://resolver.tudelft.nl/uuid:468fd021-89bd-4e15-af21-f3d3e3671257","Fracture evaluation of ultra-high-performance fiber reinforced concrete (UHPFRC)","Zhang, Youyou (Xi’an Jiaotong University); Xin, H. (TU Delft Concrete Structures; Xi’an Jiaotong University); Correia, José A.F.O. (INEGI)","","2021","The development of numerical simulation for Ultra-high-performance concrete (UHPC) and Ultra-high-performance fiber-reinforced concretes (UHPFRC) is fundamental for the design and construction of related structures. The simplified engineering stress-strain relationship and the input values are necessary in the finite element modeling. Four-linear curves and modified Kent–Park model were proposed to describe the engineering tensile and compressive stress-strain relationship, respectively. An attempt was made to simulate the fracture of UHPC and UHPFRC using concrete damaged plasticity model and element deletion strategies. The predicted tensile and compressive behaviors of UHPC and UHPFRC were successfully validated by the test results in the literature. For a better understanding of the mechanical behavior of UHPC and UHPFRC exposed to biaxial loadings, mixed-mode crack propagation simulation on the double-notched specimens exposed to combined shear-tensile and shear-compressive forces was discussed.","Engineering tensile and compressive stress-strain relationships; Mixed mode crack propagation; Ultra-high-performance concrete (UHPC); Ultra-high-performance fiber-reinforced concretes (UHPFRC)","en","journal article","","","","","","","","","","","Concrete Structures","","",""
"uuid:767cb230-cc1e-4c07-b16e-b05369a803ea","http://resolver.tudelft.nl/uuid:767cb230-cc1e-4c07-b16e-b05369a803ea","Nano-ghosts: Novel biomimetic nano-vesicles for the delivery of antisense oligonucleotides","Oieni, Jacopo (Technion); Lolli, Andrea (Erasmus MC); D'Atri, Domenico (Technion); Kops, Nicole (Erasmus MC); Yayon, Avner (Procore Ltd, Ness Ziona); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Machluf, Marcelle (Technion)","","2021","Antisense oligonucleotides (ASOs) carry an enormous therapeutic potential in different research areas, however, the lack of appropriate carriers for their delivery to the target tissues is hampering their clinical translation. The present study investigates the application of novel biomimetic nano-vesicles, Nano-Ghosts (NGs), for the delivery of ASOs to human mesenchymal stem cells (MSCs), using a microRNA inhibitor (antimiR) against miR-221 as proof-of-concept. The integration of this approach with a hyaluronic acid-fibrin (HA-FB) hydrogel scaffold is also studied, thus expanding the potential of NGs applications in regenerative medicine. The study shows robust antimiR encapsulation in the NGs using electroporation and the NGs ability to be internalized in MSCs and to deliver their cargo while avoiding endo-lysosomal degradation. This leads to rapid and strong knock-down of miR-221 in hMSCs in vitro, both in 2D and 3D hydrogel culture conditions (>90% and > 80% silencing efficiency, respectively). Finally, in vivo studies performed with an osteochondral defect model demonstrate the NGs ability to effectively deliver antimiR to endogenous cells. Altogether, these results prove that the NGs can operate as stand-alone system or as integrated platform in combination with scaffolds for the delivery of ASOs for a wide range of applications in drug delivery and regenerative medicine.","Antisense oligonucleotides; Drug delivery; microRNA; Nano-ghosts; Nanovesicles; Tissue engineering","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-09-16","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:dc3b82e4-52b9-47c2-9458-cd8c483f0831","http://resolver.tudelft.nl/uuid:dc3b82e4-52b9-47c2-9458-cd8c483f0831","Development of an adaptive CTM–RPIM method for modeling large deformation problems in geotechnical engineering","Li, Jianguo (University of Chinese Academy of Sciences; Chinese Academy of Sciences); Wang, Bin (University of Chinese Academy of Sciences; Chinese Academy of Sciences); Jiang, Quan (University of Chinese Academy of Sciences; Chinese Academy of Sciences); He, Benguo (Northeastern University); Zhang, Xue (University of Liverpool); Vardon, P.J. (TU Delft Geo-engineering)","","2021","In this paper, a meshfree method called adaptive CTM–RPIM is developed to model geotechnical problems with large deformation. The developed adaptive CTM–RPIM is a combination of the Cartesian transformation method (CTM), the radial point interpolation method (RPIM) and the alpha shape method. To reduce the requirement for meshes, the CTM is adopted to transform domain integrals into line integrals, and the RPIM is applied to construct interpolation functions. The alpha shape method, which is capable of capturing severe boundary evolution due to large deformations, is then introduced into the CTM–RPIM to form the adaptive CTM–RPIM. The accuracy of CTM–RPIM is first verified by considering a cantilever beam under small deformation, where the influence of key parameters on the simulation results is explored. Afterward, the ability of the adaptive CTM–RPIM to handle large deformation problems is demonstrated by simulating cantilever beams with large deformations for which analytical solutions are available. Finally, the ability of the proposed method to model the geotechnical large deformations is illustrated from both quasi-static and dynamic aspects, where a slope failure problem and a footing bearing capacity problem are modeled to evaluate the stability of geotechnical structures; and a 2-D soil collapse experiment using small aluminum bars is simulated to show the method capability in describing the soil flows. These benchmark examples demonstrate that the adaptive CTM–RPIM is a numerical method with broad application prospects for modeling large deformation problems in geotechnical engineering.","Alpha shape method; Cartesian transformation method; Geotechnical engineering; Large deformation; Radial point interpolation method","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-06-07","","","Geo-engineering","","",""
"uuid:5937e97f-0d98-42ad-81fa-6801001ae182","http://resolver.tudelft.nl/uuid:5937e97f-0d98-42ad-81fa-6801001ae182","Review and assessment of different perspectives of vehicle-pedestrian conflicts and crashes: Passive and active analysis approaches","Sheykhfard, A. (TU Delft Safety and Security Science; Babol Noshirvani University of Technology); Haghighi, Farshidreza (Babol Noshirvani University of Technology); Papadimitriou, E. (TU Delft Safety and Security Science); van Gelder, P.H.A.J.M. (TU Delft Safety and Security Science)","","2021","The importance of investigating pedestrian safety has been evaluated repeatedly in safety studies. The present study attempts to evaluate the various methods used by previous researchers in a hierarchical process, to determine the characteristics, advantages, and limitations of each method. Two general analysis approaches (passive and active) were taken into account to categorize 169 previous types of research. In the passive approach, the studied methods were those based on crash databases, questionnaires, and post-crash field observation data; while, in the active approach, the studied methods were those based on driving simulations and videography. The result of the passive approach reveals that road users' features and road characteristics (crash database studies), and error, lapses, intentional and unintentional violations (questionnaire studies) by them were among the most important causes of crashes and conflicts. Furthermore, road users’ distractions also reported a set of factors affecting the possibility of conflicts and crashes based on post-crash field observation studies. Also, results of the active approach showed that risky behaviors are the most important factor in threatening pedestrian safety such as unauthorized speeding, non-compliance with traffic law, unauthorized overtaking by drivers, and illegal crossing. Furthermore, risk perception and decision-making processes are the most important bond between the attitude and behavior of road users in dangerous driving situations. Examining studies through passive approach would lead to identifying the causes of crashes, recognizing the attitude of road users towards safety, and determining road users' behavioral patterns in certain situations, while the active approach has led to a more detailed understanding of behaviors and attitudes of road users. The inference of the findings obtained in this study will lead to a better understanding of the behavior of road users for studies on advanced driving assistance systems (ADAS).","Conflict; Crash; Naturalistic driving study; Pedestrian; Road safety; Traffic engineering","en","review","","","","","","","","","","","Safety and Security Science","","",""
"uuid:c4844fd6-d066-4541-b107-4021c8e1943f","http://resolver.tudelft.nl/uuid:c4844fd6-d066-4541-b107-4021c8e1943f","A study of graphical representations of uncertainty in LCA guide","Tensa, Melissa (Oregon State University); Wang, Jenna (Stanford University); Harris, Roscoe (Stanford University); Faludi, Jeremy (TU Delft Circular Product Design); DuPont, Bryony (Oregon State University)","","2021","This study user-tested different data visualizations for highly uncertain life cycle assessments (LCAs) to determine what best supported decision-making. Precise LCAs can only be performed once designs are finalized, due to the information necessary to complete them, but design changes in such late stages are costly. If designers could have environmental impact data earlier in the process, sustainable design choices could instead be built into the initial designs. We compiled LCAs for various product categories, finding the best means of visualizing the data for online and printable dissemination. Because this LCA data varied widely within each product category, it was necessary to display uncertainty and require users to acknowledge the uncertainty. Here, four different data visualizations were tested with engineering, design, and STEM students and professionals; both quantitative and qualitative analysis determined what visualizations were most favored and forced users to consider uncertainty. We hope that this research helps LCA data be more accessible to designers and engineers in the early phases of design, allowing those without the resources or ability to perform LCA to benefit from it and design more sustainably.","Design engineering; Sustainability; Visualisation","en","journal article","","","","","","","","","","","Circular Product Design","","",""
"uuid:9de5bb5c-73cf-455b-b211-693831ce8944","http://resolver.tudelft.nl/uuid:9de5bb5c-73cf-455b-b211-693831ce8944","Four Responsibility Gaps with Artificial Intelligence: Why they Matter and How to Address them","Santoni De Sio, F. (TU Delft Ethics & Philosophy of Technology); Mecacci, Giulio (Radboud Universiteit Nijmegen)","","2021","The notion of “responsibility gap” with artificial intelligence (AI) was originally introduced in the philosophical debate to indicate the concern that “learning automata” may make more difficult or impossible to attribute moral culpability to persons for untoward events. Building on literature in moral and legal philosophy, and ethics of technology, the paper proposes a broader and more comprehensive analysis of the responsibility gap. The responsibility gap, it is argued, is not one problem but a set of at least four interconnected problems – gaps in culpability, moral and public accountability, active responsibility—caused by different sources, some technical, other organisational, legal, ethical, and societal. Responsibility gaps may also happen with non-learning systems. The paper clarifies which aspect of AI may cause which gap in which form of responsibility, and why each of these gaps matter. It proposes a critical review of partial and non-satisfactory attempts to address the responsibility gap: those which present it as a new and intractable problem (“fatalism”), those which dismiss it as a false problem (“deflationism”), and those which reduce it to only one of its dimensions or sources and/or present it as a problem that can be solved by simply introducing new technical and/or legal tools (“solutionism”). The paper also outlines a more comprehensive approach to address the responsibility gaps with AI in their entirety, based on the idea of designing socio-technical systems for “meaningful human control"", that is systems aligned with the relevant human reasons and capacities.","AI and accountability; AI ethics; Engineer responsibility; Meaningful human control; Responsibility gap","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:bd76ab93-1563-4f36-92c5-37a4aaec7e2e","http://resolver.tudelft.nl/uuid:bd76ab93-1563-4f36-92c5-37a4aaec7e2e","Multi-objective evolutionary based feature selection supported by distributed multi-label classification and deep learning on image/video data","Karagoz, G. (TU Delft Data-Intensive Systems)","","2021","We live in an era in which a myriad of computer systems produce immense amounts of (raw) data every day. This big data must be processed efficiently to gain valuable and hidden knowledge. Complex processing pipelines need to be designed for filtering out irrelevant data, also for efficient data mining and machine learning methods must be used to discover useful correlations in the big data. The purpose of this PhD research is the implementation of multi-objective evolutionary-based dimensionality reduction on a high volume of image/video data with the support of distributed multi-label classification algorithms.","big data processing; dimensionality reduction; distributed machine learning; feature engineering; feature extraction","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Data-Intensive Systems","","",""
"uuid:2231beb8-c546-479a-b889-b7039a58dc86","http://resolver.tudelft.nl/uuid:2231beb8-c546-479a-b889-b7039a58dc86","A Simple and Fast Hole Detection Algorithm for Triangulated Surfaces","Vijai Kumar, S. (TU Delft Numerical Analysis); Vuik, Cornelis (TU Delft Numerical Analysis)","","2021","We present a simple and fast algorithm for computing the exact holes in discrete two-dimensional manifolds embedded in a threedimensional Euclidean space. We deal with the intentionally created ""through holes"" or ""tunnel holes"" in the geometry as opposed to missing triangles. The algorithm detects the holes in the geometry directly without any simplified geometry approximation. Discrete Gaussian curvature is used for approximating the local curvature flow in the geometry and for removing outliers from the collection of feature edges. We present an algorithm with varying degrees of flexibility. The algorithm is demonstrated separately for sheets and solid geometries. This article demonstrates the algorithm on triangulated surfaces. However, the algorithm and the underlying data structure are also applicable for surfaces with mixed polygons.","Computational geometry; Computer-aided design; Computer-aided engineering","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-08-31","","","Numerical Analysis","","",""
"uuid:8ea65686-58b4-499b-a407-4be40c83ace6","http://resolver.tudelft.nl/uuid:8ea65686-58b4-499b-a407-4be40c83ace6","Component sizing and energy management for SOFC-based ship power systems","Haseltalab, A. (TU Delft Transport Engineering and Logistics); van Biert, L. (TU Delft Ship Design, Production and Operations); Sapra, H.D. (TU Delft Ship Design, Production and Operations); Mestemaker, Benny (Royal IHC); Negenborn, R.R. (TU Delft Transport Engineering and Logistics)","","2021","The shipping industry is facing increasing demands to reduce its environmental footprints. This has resulted in adoption of new and more environmental friendly power sources and fuels for on-board power generation. One of these novel power sources is the Solid Oxide Fuel Cell (SOFC) which has a great potential to act as a power source, thanks to its high efficiency and capability to handle a wide variety of fuel types. However, SOFCs suffer from low transient capabilities and therefore have never been considered to be used as the main power source for maritime applications. In this paper, novel component sizing, energy and power management approaches are proposed to enable the use of SOFCs as the main on-board power source for the first time in the literature and integrate them into the liquefied natural gas fueled Power and Propulsion System (PPS) of vessels. The proposed component sizing approach determines the power ratings of the on-board sources (SOFC, gas engine and battery) considering size and weight limits, while the energy and power management approaches guarantee an optimal power split between different power sources and PPS stability while looking after battery aging. The results indicate that the combined proposed optimization-based approaches can yield up to 53% CO2 reduction and 21% higher fuel utilization efficiency compared to conventional diesel-electric vessels.","Battery; Energy management; Gas engine; Hybrid power generation; Power and propulsion systems; Solid oxide fuel cells","en","journal article","","","","","","","","","","","Transport Engineering and Logistics","","",""
"uuid:d55feeb5-4823-4589-901d-d3ffdef8389d","http://resolver.tudelft.nl/uuid:d55feeb5-4823-4589-901d-d3ffdef8389d","Novel oleate hydratases and potential biotechnological applications","Hagedoorn, P.L. (TU Delft BT/Biocatalysis); Hollmann, F. (TU Delft BT/Biocatalysis); Hanefeld, U. (TU Delft BT/Biocatalysis)","","2021","Oleate hydratase catalyses the addition of water to the CC double bond of oleic acid to produce (R)-10-hydroxystearic acid. The enzyme requires an FAD cofactor that functions to optimise the active site structure. A wide range of unsaturated fatty acids can be hydrated at the C10 and in some cases the C13 position. The substrate scope can be expanded using ‘decoy’ small carboxylic acids to convert small chain alkenes to secondary alcohols, albeit at low conversion rates. Systematic protein engineering and directed evolution to widen the substrate scope and increase the conversion rate is possible, supported by new high throughput screening assays that have been developed. Multi-enzyme cascades allow the formation of a wide range of products including keto-fatty acids, secondary alcohols, secondary amines and α,ω-dicarboxylic acids. Key points: • Phylogenetically distinct oleate hydratases may exhibit mechanistic differences. • Protein engineering to improve productivity and substrate scope is possible. • Multi-enzymatic cascades greatly widen the product portfolio.","10-hydroxystearic acid; Biocatalysis; Oleate hydratase; Protein engineering","en","review","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:b4cb7f7d-0c4f-40ba-944c-a4fe9e2d47cc","http://resolver.tudelft.nl/uuid:b4cb7f7d-0c4f-40ba-944c-a4fe9e2d47cc","Engineering the thermotolerant industrial yeast Kluyveromyces marxianus for anaerobic growth","Dekker, W.J.C. (TU Delft BT/Industriele Microbiologie); Ortiz Merino, R.A. (TU Delft BT/Industriele Microbiologie); Kaljouw, Astrid (Student TU Delft); Battjes, Julius (Student TU Delft); Wiering, Frank W. (Student TU Delft); Mooiman, C. (TU Delft BT/Bioprocess Engineering); de la Torre, P. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie)","","2021","Current large-scale, anaerobic industrial processes for ethanol production from renewable carbohydrates predominantly rely on the mesophilic yeast Saccharomyces cerevisiae. Use of thermotolerant, facultatively fermentative yeasts such as Kluyveromyces marxianus could confer significant economic benefits. However, in contrast to S. cerevisiae, these yeasts cannot grow in the absence of oxygen. Responses of K. marxianus and S. cerevisiae to different oxygen-limitation regimes were analyzed in chemostats. Genome and transcriptome analysis, physiological responses to sterol supplementation and sterol-uptake measurements identified absence of a functional sterol-uptake mechanism as a key factor underlying the oxygen requirement of K. marxianus. Heterologous expression of a squalene-tetrahymanol cyclase enabled oxygen-independent synthesis of the sterol surrogate tetrahymanol in K. marxianus. After a brief adaptation under oxygen-limited conditions, tetrahymanol-expressing K. marxianus strains grew anaerobically on glucose at temperatures of up to 45 °C. These results open up new directions in the development of thermotolerant yeast strains for anaerobic industrial applications.","Anaerobic metabolism; Ergosterol; Ethanol production; Metabolic engineering; Tetrahymanol; Thermotolerance; Yeast biotechnology","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:5bc70e77-4c7f-4895-9cba-376a462f6bb9","http://resolver.tudelft.nl/uuid:5bc70e77-4c7f-4895-9cba-376a462f6bb9","Optimization and Engineering of Fatty Acid Photodecarboxylase for Substrate Specificity","Santner, Paul (Aarhus University); Szabó, László Krisztián (Aarhus University); Chanquia, Santiago Nahuel (Aarhus University); Merrild, Aske Høj (Aarhus University); Hollmann, F. (TU Delft BT/Biocatalysis); Kara, S. (TU Delft BT/Biocatalysis; Aarhus University); Eser, Bekir Engin (Aarhus University)","","2021","Fatty acid photodecarboxylase (FAP) is one of the few photoenzymes in nature. The ability of FAP to convert fatty acids into alka(e)nes without the need for reducing equivalents put this enzyme into spotlight for biocatalytic applications. Although it has been discovered only a few years ago, many studies already emerged demonstrating its potential in areas from biofuel production and enzymatic kinetic resolution to being a critical component of multi-enzyme cascades. While there have been few protein engineering studies for modulating activity of FAP towards very short chain fatty acids, no study has yet addressed substrate selectivity within the medium to long chain fatty acid range, where FAP shows great promise for the synthesis of drop-in biofuels from ubiquitous fatty acids with chain lengths from C12 to C18. Here, after determining optimum expression and assay conditions for FAP, we screened 22 rationally designed mutant enzymes towards four naturally abundant fatty acid substrates; C12 : 0, C16 : 0, C18 : 0 and C18 : 1. Depending on the type of the exchanged amino acid, we observed selectivity shifts towards shorter or longer chains, compared to wild type enzyme. Notably, we obtained two groups of mutants; one group with high selectivity towards only C18 : 0, and another group that is selective towards C12 : 0 substrate. Moreover, we measured light and thermal stability of the wild type enzyme as well as the light stability of a mutant engineered for selectivity.","Biocatalysis; Drop-in Biofuels; Fatty Acid Photodecarboxylase; Photoenzyme; Protein Engineering","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-01-12","","","BT/Biocatalysis","","",""
"uuid:97c733bd-f8d9-4181-a94d-1131cb335332","http://resolver.tudelft.nl/uuid:97c733bd-f8d9-4181-a94d-1131cb335332","End to end process evaluation for additively manufactured liquid rocket engine thrust chambers","Kerstens, Fabio (Student TU Delft); Cervone, A. (TU Delft Space Systems Egineering); Gradl, P.R. (NASA Marshall Space Flight Center)","","2021","High performance liquid rocket engines require cooling to maintain structural integrity of the combustion chamber which is exposed to high thermal and environmental loads. For many systems, this is achieved by means of regenerative cooling, where a coolant flows through passages around the chamber wall whilst extracting heat from the wall. A novel production technique that is often considered for this is metal additive manufacturing (AM). The use of additive manufacturing opens up new opportunities for engine design, which can result in more competitive designs, from both a technical and economical perspective. This paper provides a detailed literature review on the current state-of-the-art, challenges, and opportunities for designing additively manufactured liquid rocket engines by means of laser powder bed fusion or powder-based and wire-based directed energy deposition (DED) techniques. A detailed, systematic explanation is provided on the steps involving the creation of additively manufactured thrusters including the process considerations, AM techniques and post-processing operations.","Additive manufacturing; Directed energy deposition; Liquid rocket engine; Powder bed fusion; Regenerative cooling; Thrust chamber","en","journal article","","","","","","","","2023-03-06","","","Space Systems Egineering","","",""
"uuid:cc6b0da6-1d5d-4a7a-8c46-9682e96902ef","http://resolver.tudelft.nl/uuid:cc6b0da6-1d5d-4a7a-8c46-9682e96902ef","Team design patterns for moral decisions in hybrid intelligent systems: A case study of bias mitigation","van Stijn, Jip J. (Vrije Universiteit Amsterdam); Neerincx, M.A. (TU Delft Interactive Intelligence; TNO); ten Teije, Annette (Vrije Universiteit Amsterdam); Vethman, Steven (TNO)","","2021","Increasing automation in the healthcare sector calls for a Hybrid Intelligence (HI) approach to closely study and design the collaboration of humans and autonomous machines. Ensuring that medical HI systems' decision-making is ethical is key. The use of Team Design Patterns (TDPs) can advance this goal by describing successful and reusable configurations of design problems in which decisions have a moral component and facilitating communication in multidisciplinary teams designing HI systems. For this research, TDPs were developed describing a set of solutions for a design problem in a medical HI system: mitigating harmful biases in machine learning algorithms. The Socio-Cognitive Engineering (SCE) methodology was employed, integrating operational demands, human factors knowledge, and a technological analysis into a set of TDPs. A survey was created to assess the usability of the patterns with regards to their understandability, effectiveness, and generalizability. Results showed that TDPs are a useful method to unambiguously describe solutions for diverse HI design problems with a moral component on varying abstraction levels, usable by a heterogeneous group of multidisciplinary researchers. Additionally, results indicated that the SCE approach and the developed questionnaire are suitable methods for creating and assessing TDPs.","Bias mitigation; Hybrid intelligence; Moral decision-making; Socio-cognitive engineering; Team design patterns; Value-sensitive design","en","journal article","","","","","","","","","","","Interactive Intelligence","","",""
"uuid:4eebfc78-4bf6-473a-a2e1-104c892e9df2","http://resolver.tudelft.nl/uuid:4eebfc78-4bf6-473a-a2e1-104c892e9df2","Establishing Platoons of Bidirectional Cooperative Vehicles with Engine Limits and Uncertain Dynamics","Baldi, S. (TU Delft Team Bart De Schutter; Southeast University); Liu, Di (Southeast University; Rijksuniversiteit Groningen); Jain, V. (TU Delft Intelligent Vehicles); Yu, Wenwu (Southeast University)","","2021","In adaptive platooning strategies proposed in literature to handle uncertain and nonidentical uncertain vehicle dynamics (uncertain heterogeneous platoons) two aspects requiring proper design are neglected: bidirectional interaction among vehicles which might lead to loss of string stability, and engine saturation constraints which might lead to loss of cohesiveness. This work proposes a novel adaptive platooning strategy handling these two crucial aspects. Specifically, bidirectional interaction is handled by designing bidirectional reference dynamics with proven string stability properties, to which the uncertain heterogeneous platoon should homogenize; engine constraints are handled via a proposed a mechanism that makes such reference dynamics 'not too demanding', by properly saturating their action. The saturation action will allow all vehicles in the platoon to not hit their engine limits, preserving cohesiveness. Simulations are conducted to validate the theoretical analysis and show the effectiveness of the method in retaining cohesiveness of the platoon.","bidirectional communication; Cooperative adaptive cruise control; engine constraints; heterogeneous platoon","en","journal article","","","","","","Accepted Author Manuscript","","","","","Team Bart De Schutter","","",""
"uuid:09fc312d-95d2-417e-804b-329f85c54785","http://resolver.tudelft.nl/uuid:09fc312d-95d2-417e-804b-329f85c54785","Contributing human and organizational factors to the collapse of the FC Twente stadium roof","Terwel, K.C. (TU Delft Applied Mechanics)","","2021","In 2011 the city of Enschede was shocked by the collapse of the roof of an extension for the FC Twente stadium. The structure collapsed during construction and two fatalities and nine injuries were recorded. The cantilevering steel roof structure was covered with corrugated steel sheets and stabilized by bracings. Investigation showed that the structure was already loaded with the finishing structure before it was completed and stabilized. Contributing influencing human and organizational factors to the incident were the tight schedule resulting in a flawed construction sequence. Furthermore, there was too little attention to the way of execution during design, unjustified trust between parties resulting in inadequate coordination, checking and allocation of responsibilities.","Causes of failure; Forensic engineering; Human and organizational factors","en","conference paper","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-03-24","","","Applied Mechanics","","",""
"uuid:f00f8aa8-6fd5-4b61-9505-318cfb8df0f3","http://resolver.tudelft.nl/uuid:f00f8aa8-6fd5-4b61-9505-318cfb8df0f3","Systems approaches to healthcare systems design and care delivery: An overview of the literature","Komashie, Alexander (University of Cambridge); Hinrichs-Krapels, S. (TU Delft Multi Actor Systems; TU Delft Policy Analysis); Clarkson, P.J. (TU Delft Applied Ergonomics and Design; University of Cambridge)","","2021","The healthcare sector is facing significant challenges that require a systems approach, resulting in a rapid growth in the application of systems approaches in healthcare since the beginning of the 21st century. Consequently, healthcare practitioners and policymakers now desire to understand the evidence-base for the approach, but little evidence of the kind desired exists. This paper is a first step in conducting a narrative review of the application of systems approaches in healthcare based on a systematic review of the academic and grey literature. First, the emergence of the approach in healthcare is explored. Second, specific examples of applications of systems approaches in healthcare are examined to identify any missing elements in current practice. Third, fourteen reviews of the approach in healthcare published in the last ten years are analysed. The results suggest that the use of the approach in healthcare will most likely continue to increase, however, significant work remains for the design and systems community to demonstrate the effectiveness of systems approaches, specifically in providing convincing measures of impact on patient and service outcomes.","Design engineering; Healthcare design; Healthcare quality improvement; Service design; Systems Engineering (SE)","en","journal article","","","","","","","","","","Multi Actor Systems","Policy Analysis","","",""
"uuid:d1cc1030-d97a-4cfc-8219-2596803e4a06","http://resolver.tudelft.nl/uuid:d1cc1030-d97a-4cfc-8219-2596803e4a06","Dynamic responses of the aero-engine rotor system to bird strike on fan blades at different rotational speeds","Wu, Bin (Tianjin University); Lin, Jiewei (Tianjin University); Hedayati, R. (TU Delft Novel Aerospace Materials); Zhang, Guichang (Civil Aviation University of China); Zhang, Junhong (Tianjin University; Tianjin Ren’ai College); Zhang, Lipeng (Tianjin University)","","2021","To study the effect of a bird striking engine fan on the rotor system, a low-pressure rotor system dynamic model based on a real aero-engine structure was established. Dynamic equations were derived considering the case of the bird strike force which transferred to the rotor system. The bird strike force was obtained from the bird strike process simulation in LS-DYNA, where a smoothed particle hydrodynamics (SPH) mallard model was constructed using a computed tomog-raphy (CT) scanner, and finite element method (FEM) was used to simulate the bird strike on an actual fan model. The dynamic equations were solved using the Newmark-β method. The effect of rotational speeds on the rotor system dynamics after bird strike was investigated and discussed. Results show that the maximum bird impact force can reach 104 kN at 3772 r/min. Impact time is only 0.06 s, but the bird strike on fan blades lead to a transient shock on the rotor system. Under the action of transient shocks, the rotor system displacement in the horizontal and vertical directions increase sharply, and the closer the mass point is to the fan, the more it is affected; the vibration amplitude at the fan will increase 15 times within 0.1 s of the bird strike and will gradually decrease with the effect of damping. The dynamics of the rotor system changes from a stable single periodic motion to a complex irregular quasi-periodic motion after a bird strike, and the strike force excites the first-order vibrational mode of the rotor system. This phenomenon occurs at all speeds when bird strikes occur. Bird strikes will cause resonance in the rotor system, which may cause damage to the engine. It was also seen that the bird strike force, and hence the effects on the rotor system, increases as the engine rotational speed increases; the peak force is larger and the number of peaks has increased. The impact force at 3772 r/min is 99.5 kN higher than at 836 r/min, and three additional peaks emerged. This effect is more reflected in the amplitude, and the overall vibration characteristics do not change. Combining the bird strike with the rotor dynamics calculation, the dynamic response of the aero-engine rotor system to bird strike is studied at different flight stages, which is of guiding significance for power evaluation of aero engines after bird strike.","Aero-engine rotor system; Bird strike; Dynamic responses; SPH","en","journal article","","","","","","","","","","","Novel Aerospace Materials","","",""
"uuid:c4715cd7-79cf-448d-9035-13f947789bc6","http://resolver.tudelft.nl/uuid:c4715cd7-79cf-448d-9035-13f947789bc6","Editorial: Perspectives of Chemicals Synthesis as a Green Alternative to Fossil Fuels","Puigjaner, Luis (Universitat Politecnica de Catalunya); Pérez-Fortes, Mar (TU Delft Energie and Industrie); Somoza-Tornos, Ana (Universitat Politecnica de Catalunya; University of Colorado); Espuña, Antonio (Universitat Politecnica de Catalunya)","","2021","","circular economy; economic competitiveness; green fuels; LCA; low carbon processes; process systems engineering; sustainable development","en","contribution to periodical","","","","","","","","","","","Energie and Industrie","","",""
"uuid:c0d56610-2c26-4700-88ba-d56f96a2619d","http://resolver.tudelft.nl/uuid:c0d56610-2c26-4700-88ba-d56f96a2619d","Satellite image processing for the coarse-scale investigation of sandy coastal areas","Latella, Melissa (Politecnico di Torino); Luijendijk, Arjen (TU Delft Coastal Engineering; Deltares); Moreno-Rodenas, Antonio M. (Deltares); Camporeale, Carlo (Politecnico di Torino)","","2021","In recent years, satellite imagery has shown its potential to support the sustainable management of land, water, and natural resources. In particular, it can provide key information about the properties and behavior of sandy beaches and the surrounding vegetation, improving the ecomor-phological understanding and modeling of coastal dynamics. Although satellite image processing usually demands high memory and computational resources, free online platforms such as Google Earth Engine (GEE) have recently enabled their users to leverage cloud-based tools and handle big satellite data. In this technical note, we describe an algorithm to classify the coastal land cover and retrieve relevant information from Sentinel-2 and Landsat image collections at specific times or in a multitemporal way: the extent of the beach and vegetation strips, the statistics of the grass cover, and the position of the shoreline and the vegetation–sand interface. Furthermore, we validate the algorithm through both quantitative and qualitative methods, demonstrating the goodness of the derived classification (accuracy of approximately 90%) and showing some examples about the use of the algorithm’s output to study coastal physical and ecological dynamics. Finally, we discuss the algorithm’s limitations and potentialities in light of its scaling for global analyses.","Beach monitoring; Coastal vegetation; Geomorphology; Google Earth Engine; Satellite images; Shoreline detection","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:0ed75e21-3bf2-496f-9cda-db936da231ab","http://resolver.tudelft.nl/uuid:0ed75e21-3bf2-496f-9cda-db936da231ab","Initiatives, experiences and best practices for teaching social and ecological responsibility in ethics education for science and engineering students","Børsen, Tom (Aalborg University); Serreau, Yann (Lineact Cesi, Arras); Reifschneider, Kiera (Arizona State University); Baier, André (Technical University of Berlin); Pinkelman, Rebecca (Technische Universität Darmstadt); Smetanina, Tatiana (Udmurt State University); Zandvoort, H. (TU Delft Ethics & Philosophy of Technology)","","2021","For the past 14 years the Social Ecological Responsibility in Science and Engineering Education (SERSEE) Network has discussed the challenging but necessary task of teaching social and ecological responsibility to science and engineering students. Identifying, sharing and developing best practices, pedagogical materials and tools as well as a strategy for promoting it at universities can aid and promote this endeavour. This paper presents the central concepts and pedagogical methods that have emerged during the informal network’s meetings, and compares these concepts and methods to trends in the research literature.","engineering education; Ethics; science education; social responsibility; sustainability","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:086bf9f2-595c-4a77-8a62-f2f228b67581","http://resolver.tudelft.nl/uuid:086bf9f2-595c-4a77-8a62-f2f228b67581","Asymmetric Cation-Olefin Monocyclization by Engineered Squalene–Hopene Cyclases","Eichenberger, Michael (Zurich University of Applied Science (ZHAW)); Hüppi, S.N. (TU Delft BT/Biocatalysis; Zurich University of Applied Science (ZHAW)); Patsch, David (Zurich University of Applied Science (ZHAW); Greifswald University); Aeberli, Natalie (Fragrances S & T, Kemptthal); Berweger, Raphael (Fragrances S & T, Kemptthal); Dossenbach, Sandro (Fragrances S & T, Kemptthal); Eichhorn, Eric (Fragrances S & T, Kemptthal); Flachsmann, Felix (Fragrances S & T, Kemptthal); Hortencio, Lucas (Fragrances S & T, Kemptthal)","","2021","Squalene–hopene cyclases (SHCs) have great potential for the industrial synthesis of enantiopure cyclic terpenoids. A limitation of SHC catalysis has been the enzymes’ strict (S)-enantioselectivity at the stereocenter formed after the first cyclization step. To gain enantio-complementary access to valuable monocyclic terpenoids, an SHC-wild-type library including 18 novel homologs was set up. A previously not described SHC (AciSHC) was found to synthesize small amounts of monocyclic (R)-γ-dihydroionone from (E/Z)-geranylacetone. Using enzyme and process optimization, the conversion to the desired product was increased to 79 %. Notably, analyzed AciSHC variants could finely differentiate between the geometric geranylacetone isomers: While the (Z)-isomer yielded the desired monocyclic (R)-γ-dihydroionone (>99 % ee), the (E)-isomer was converted to the (S,S)-bicyclic ether (>95 % ee). Applying the knowledge gained from the observed stereodivergent and enantioselective transformations to an additional SHC-substrate pair, access to the complementary (S)-γ-dihydroionone (>99.9 % ee) could be obtained.","chemoenzymatic synthesis; cyclization; protein engineering; squalene–hopene cyclases; substrate engineering","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:513e4f13-1627-455a-89fa-0e53e0133892","http://resolver.tudelft.nl/uuid:513e4f13-1627-455a-89fa-0e53e0133892","A Tailor-Made Deazaflavin-Mediated Recycling System for Artificial Nicotinamide Cofactor Biomimetics","Drenth, Jeroen (Rijksuniversiteit Groningen); Yang, Guang (Rijksuniversiteit Groningen); Paul, C.E. (TU Delft BT/Biocatalysis); Fraaije, Marco W. (University Medical Center Groningen; Rijksuniversiteit Groningen)","","2021","Nicotinamide adenine dinucleotide (NAD) and its 2′-phosphorylated form NADP are crucial cofactors for a large array of biocatalytically important redox enzymes. Their high cost and relatively poor stability, however, make them less attractive electron mediators for industrial processes. Nicotinamide cofactor biomimetics (NCBs) are easily synthesized, are inexpensive, and are also generally more stable than their natural counterparts. A bottleneck for the application of these artificial hydride carriers is the lack of efficient cofactor recycling methods. Therefore, we engineered the thermostable F420:NADPH oxidoreductase from Thermobifida fusca (Tfu-FNO), by structure-inspired site-directed mutagenesis, to accommodate the unnatural N1 substituents of eight NCBs. The extraordinarily low redox potential of the natural cofactor F420H2 was then exploited to reduce these NCBs. Wild-type enzyme had detectable activity toward all selected NCBs, with Km values in the millimolar range and kcat values ranging from 0.09 to 1.4 min-1. Saturation mutagenesis at positions Gly-29 and Pro-89 resulted in mutants with up to 139 times higher catalytic efficiencies. Mutant G29W showed a kcat value of 4.2 s-1 toward 1-benzyl-3-acetylpyridine (BAP+), which is similar to the kcat value for the natural substrate NADP+. The best Tfu-FNO variants for a specific NCB were then used for the recycling of catalytic amounts of these nicotinamides in conversion experiments with the thermostable ene-reductase from Thermus scotoductus (TsOYE). We were able to fully convert 10 mM ketoisophorone with BAP+ within 16 h, using F420 or its artificial biomimetic FOP (FO-2′-phosphate) as an efficient electron mediator and glucose-6-phosphate as an electron donor. The generated toolbox of thermostable and NCB-dependent Tfu-FNO variants offers powerful cofactor regeneration biocatalysts for the reduction of several artificial nicotinamide biomimetics at both ambient and high temperatures. In fact, to our knowledge, this enzymatic method seems to be the best-performing NCB-recycling system for BNAH and BAPH thus far.","artificial cofactors; deazaflavins; enzymatic recycling system; enzyme engineering; F; nicotinamide biomimetics; redox enzymology","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:7188640f-9407-4155-bf28-6d5f57024d68","http://resolver.tudelft.nl/uuid:7188640f-9407-4155-bf28-6d5f57024d68","Effect of Co-Solvents on the Crystallization and Phase Distribution of Mixed-Dimensional Perovskites","Caiazzo, Alessandro (Eindhoven University of Technology); Datta, Kunal (Eindhoven University of Technology); Jiang, Junke (Eindhoven University of Technology); Gelvez Rueda, M.C. (TU Delft ChemE/Opto-electronic Materials); Li, Junyu (Eindhoven University of Technology); Ollearo, Riccardo (Eindhoven University of Technology); Vicent-Luna, José Manuel (Eindhoven University of Technology); Tao, Shuxia (Eindhoven University of Technology); Grozema, F.C. (TU Delft ChemE/Opto-electronic Materials)","","2021","Solution-processed quasi-2D perovskites are promising for stable and efficient solar cells because of their superior environmental stability compared to 3D perovskites and tunable optoelectronic properties. Changing the number of inorganic layers (n) sandwiched between the organic spacers allows for tuning of the bandgap. However, narrowing the phase distribution around a specific n-value is a challenge. In-situ UV–vis–NIR absorption spectroscopy is used to time-resolve the crystallization dynamics of quasi-2D butylammonium-based (BA) perovskites with <n> = 4, processed from N,N-dimethylformamide (DMF) in the presence of different co-solvents. By combining with photoluminescence, transient absorption, and grazing-incidence wide-angle X-ray scattering, the crystallization is correlated to the distribution of phases with different n-values. Infrared spectroscopy and density functional theory reveal that the phase distribution correlates with perovskite precursor—co-solvent interaction energies and that stronger interactions shift the phase distribution towards smaller n-values. Careful tuning of the solvent/co-solvent ratio provides a more homogeneous phase distribution, with highly oriented perovskite crystals and suppressed formation of n = 1–2 phases, providing a power conversion efficiency for BA2MA3Pb4I13 solar cells that increases from 3.5% when processed from DMF to over 11% and 10% when processed from DMF/dimethyl sulfoxide and DMF/N-methyl-2-pyrrolidone mixtures, respectively.","crystallization; film formation; Ruddlesden-Popper perovskites; solar cells; solvent engineering","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:f9c9f014-5e5f-49df-bd77-586e21ba95d7","http://resolver.tudelft.nl/uuid:f9c9f014-5e5f-49df-bd77-586e21ba95d7","New insights into the failure mechanisms of horizontal plate anchors in clay during pull-out","Jalilvand, Soroosh (University College Dublin; Gavin and Doherty Geosolutions); Gavin, Kenneth (TU Delft Geo-engineering); Sivakumar, Vinayagamoothy (Queen's University Belfast); Gilbert, Robert B. (The University of Texas at Austin); Bradshaw, Aaron (University of Rhode Island)","","2021","Offshore wind developments are moving towards deep-water regions where energy is abundant, visual impact is minimised and the larger turbine sizes can make the energy production more cost-effective. One of the key challenges facing the industry is the development of reliable substructures. While fixed foundation systems are widely used for shallow-water (<60 m) developments, permanent anchors are seen as one of the most viable mooring solutions for floating structures in deep water. In the current study, the pull-out behaviour of square plate anchors in clay was investigated using large-displacement finite-element analysis. The anchor capacity and failure mechanism were considered for a range of embedment ratios and undrained shear strengths. Three distinct modes of anchor failure identified in previous studies were examined through the analysis of four descriptors including: the pull-out capacity of the anchor, the pull-out displacement required to mobilise this capacity, the energy absorbed by the anchor during pull-out and the variation of the pull-out capacity with respect to a normalised overburden pressure. The findings of the study are presented in the form of a series of charts that can aid design through understanding of the factors controlling the development of anchor failure modes, in addition to identifying the transition point between different failure mechanisms.","anchors & anchorages; finite-element modelling; offshore engineering","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-06-14","","","Geo-engineering","","",""
"uuid:c4f7bd33-9ae1-4277-925f-7d90e4f2b3ef","http://resolver.tudelft.nl/uuid:c4f7bd33-9ae1-4277-925f-7d90e4f2b3ef","Towards a synthetic biology toolset for metallocluster enzymes in biosynthetic pathways: What we know and what we need","Shomar, Helena (Université de Paris); Bokinsky, G.E. (TU Delft BN/Greg Bokinsky Lab; Kavli institute of nanoscience Delft)","","2021","Microbes are routinely engineered to synthesize high-value chemicals from renewable materials through synthetic biology and metabolic engineering. Microbial biosynthesis often relies on expression of heterologous biosynthetic pathways, i.e., enzymes transplanted from foreign organisms. Metallocluster enzymes are one of the most ubiquitous family of enzymes involved in natural product biosynthesis and are of great biotechnological importance. However, the functional expression of recombinant metallocluster enzymes in live cells is often challenging and represents a major bottleneck. The activity of metallocluster enzymes requires essential supporting pathways, involved in protein maturation, electron supply, and/or enzyme stability. Proper function of these supporting pathways involves specific protein–protein interactions that remain poorly characterized and are often overlooked by traditional synthetic biology approaches. Consequently, engineering approaches that focus on enzymatic expression and carbon flux alone often overlook the particular needs of metallocluster enzymes. This review highlights the biotechnological relevance of metallocluster enzymes and discusses novel synthetic biology strategies to advance their industrial application, with a particular focus on iron-sulfur cluster enzymes. Strategies to enable functional heterologous expression and enhance recombinant metallocluster enzyme activity in industrial hosts include: (1) optimizing specific maturation pathways; (2) improving catalytic stability; and (3) enhancing electron transfer. In addition, we suggest future directions for developing microbial cell factories that rely on metallocluster enzyme catalysis.","Electron transfer; Enzyme maturation; FeS cluster; Heterologous expres-sion; Metabolic engineering; Metallocluster enzymes; Microbial biosynthesis; Synthetic biology","en","review","","","","","","","","","","","BN/Greg Bokinsky Lab","","",""
"uuid:db9e3079-4090-425c-97a7-5bc9721e57f4","http://resolver.tudelft.nl/uuid:db9e3079-4090-425c-97a7-5bc9721e57f4","Lateral response of rigid monopiles subjected to cyclic loading: Centrifuge modelling","Li, Q. (TU Delft Geo-engineering); Askarinejad, A. (TU Delft Geo-engineering); Gavin, Kenneth (TU Delft Geo-engineering)","","2021","In this study, a total number of 20 centrifuge tests were carried out to investigate monopile behaviour under lateral cyclic loading. The instrumented model pile simulates an offshore wind turbine foundation with an embedment ratio of 5 installed in sand layers with two relative densities of 80% and 50%. The influence of the directional characteristic and amplitude of cyclic load on pile lateral behaviour was studied. The data analysis focused on the influence of cyclic load on the accumulation of lateral displacement and evolution of secant stiffness of the foundation system. The most damaging cyclic load type (which can cause the most accumulated pile displacement) is identified as two-way loading, and it was observed that cyclic load always increases the pile secant stiffness. A new model for the prediction of evolution of accumulated displacement and change in secant stiffness has been formulated. An example of the procedure developed is presented for a typical field monopile subjected to cyclic loading. Lastly, the performance of the new model is demonstrated and predicted results are compared with field test data.","dynamics; offshore engineering; piles & piling","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-06-16","","","Geo-engineering","","",""
"uuid:acb3b85e-eac1-429d-9ef4-292c3ff8a521","http://resolver.tudelft.nl/uuid:acb3b85e-eac1-429d-9ef4-292c3ff8a521","Mapping mangrove opportunities with open access data: A case study for Bangladesh","Gijón Mancheño, A. (TU Delft Hydraulic Structures and Flood Risk); Herman, P.M.J. (TU Delft Environmental Fluid Mechanics; Deltares); Jonkman, Sebastiaan N. (TU Delft Hydraulic Structures and Flood Risk); Kazi, Swarna (World Bank); Urrutia, Ignacio (World Bank); van Ledden, Mathijs (The World Bank)","","2021","Mangroves protect coastal areas against hazards like storms or cyclones by attenuating waves and currents, and by trapping floating debris during extreme events. Bangladesh is a very vulnerable country to floods and cyclones, and part of its coastal system is thus being upgraded to a higher safety standard. These upgrades include embankment reinforcement and mangrove afforestation schemes seawards of the embankments. To further strengthen the implementation of combined green–grey infrastructure in future programs, identifying potential mangrove development sites near the polder systems is a necessary first step. We thus developed a tool to systematically identify mangrove sites throughout the coastal area based on open access data. This method identi-fies potential sites for mangrove development based on their distance from existing mangrove patches and suggests the required technique to implement the vegetation depending on the rate of coastline change. Our method showed that approximately 600 km of the coastal stretches placed seawards of embankments are within 10 km of existing mangroves, and could thus be potential sites for mangrove establishment. Out of those 600 km, we identified 140 km of coastline where the land-wards polders are particularly vulnerable to flooding. The sites with highest restoration potential and priority are located in Galachipa, Hatiya, Bhola, Manpura, Khangona, and Boro Moheshkhali. More detailed data collection and local assessments are recommended prior to executing mangrove afforestation schemes. Nevertheless, this method could serve as a useful systematic tool for feasi-bility studies that identify mangrove opportunities in data-scarce areas and help to prioritize data collection at the sites of highest interest.","Building with nature; Hybrid engineering; Mangrove afforestation; Mangrove mapping; Vegetated fore-shores","en","journal article","","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:a0db2eb6-f978-41e6-b819-d192f81bc0f1","http://resolver.tudelft.nl/uuid:a0db2eb6-f978-41e6-b819-d192f81bc0f1","Water System Examples for Control Education","van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (TU Delft Team Bart De Schutter)","","2021","Management of water systems is becoming more and more complex; this creates opportunities for the application of control theory. These opportunities are the subject of a course on operational water management given to students of the water management department, Delft University of Technology, over the past 15 years. Traditional examples in control theory courses are taken from industry and do not easily map to water systems, so examples were developed that use water systems to illustrate control theory concepts. This provided the students with a link between control theory and water management practice.","Control education; other engineers; quantity management; Sampled data systems; Systems with delay; Teaching curricula developments for control; Water quality","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:90c5bb67-3f49-42ff-8f04-cb066a0d9881","http://resolver.tudelft.nl/uuid:90c5bb67-3f49-42ff-8f04-cb066a0d9881","Conservation Implications of Sabellaria spinulosa Reef Patches in a Dynamic Sandy-Bottom Environment","van der Reijden, Karin J. (University Medical Center Groningen); Koop, L. (TU Delft Aircraft Noise and Climate Effects); Mestdagh, S.M.F. (NIOZ Royal Netherlands Institute for Sea Research); Snellen, M. (TU Delft Aircraft Noise and Climate Effects; Deltares); Herman, P.M.J. (TU Delft Hydraulic Engineering; TU Delft Environmental Fluid Mechanics; Deltares); Olff, Han (University Medical Center Groningen); Govers, Laura L. (University Medical Center Groningen; NIOZ Royal Netherlands Institute for Sea Research)","","2021","Biogenic reefs form biodiversity hotspots and are key components of marine ecosystems, making them priority habitats for nature conservation. However, the conservation status of biogenic reefs generally depends on their size and stability. Dynamic, patchy reefs may therefore be excluded from protection. Here, we studied epibenthos and epifauna density, richness, and community composition of patchy, dynamic Sabellaria spinulosa (ross worm) reefs in the North Sea. This study was conducted by comparing boxcore (endobenthos) and video transect (epifauna) data from two research campaigns in 2017 and 2019 to the Brown Bank area on the Dutch Continental Shelf, where S. spinulosa reefs were first discovered in 2017. The Brown Bank area is characterized by dynamic, migratory bedforms at multiple scales which potentially affect biogenic reef stability. We showed that S. spinulosa habitats had a patchy distribution and alternated with habitats comprised of plain sand. Average S. spinulosa habitat patch size was 5.57 ± 0.99 m and 3.94 ± 0.22 m in 2017 and 2019, respectively (mean ± SE), which especially in 2019 closely resembled the small-scale megaripple bedforms. Contrary to the endobenthos communities that were unaffected by S. spinulosa, epifauna density and species richness were at least two times higher in S. spinulosa habitats compared to sandy habitats, resulting in different community compositions between the two habitat types. We showed that S. spinulosa persisted in the area for almost 2 years. Although the stability of individual patches remained unclear, we demonstrated that even patchy biogenic reefs may promote density and local biodiversity of mobile, epibenthic species, very likely as a result of increased habitat heterogeneity provided by reef habitat patches. This indicates that patchy biogenic reefs that occur in dynamic environments may also have high ecological value and their conservation status should be (re)considered to ensure their protection.","biogenic reefs; ecosystem engineering; habitat heterogeneity; marine management; megaripples; North Sea; patchiness; ross worm","en","journal article","","","","","","","","","","Hydraulic Engineering","Aircraft Noise and Climate Effects","","",""
"uuid:fed719c2-1cab-42c2-97a2-29739d0577d5","http://resolver.tudelft.nl/uuid:fed719c2-1cab-42c2-97a2-29739d0577d5","Oil Spaces: Exploring the Global Petroleumscape","","Hein, C.M. (editor)","2021","Oil Spaces traces petroleum’s impact through a range of territories from across the world, showing how industrially drilled petroleum and its refined products have played a major role in transforming the built environment in ways that are often not visible or recognized. Over the past century and a half, industrially drilled petroleum has powered factories, built cities, and sustained nation-states. It has fueled ways of life and visions of progress, modernity, and disaster.
In detailed international case studies, the contributors consider petroleum’s role in the built environment and the imagination. They study how petroleum and its infrastructure have served as a source of military conflict and political and economic power, inspiring efforts to create territories and reshape geographies and national boundaries. The authors trace ruptures and continuities between colonial and postcolonial frameworks, in locations as diverse as Sumatra, northeast China, Brazil, Nigeria, Tanzania, and Kuwait as well as heritage sites including former power stations in Italy and the port of Dunkirk, once a prime gateway through which petroleum entered Europe.
By revealing petroleum’s role in organizing and imagining space globally, this book takes up a key task in imagining the possibilities of a post-oil future. It will be invaluable reading to scholars and students of architectural and urban history, planning, and geography of sustainable urban environments.","Built Environment; Economics; Finance; Business & Industry; Engineering & Technology; Environment & Agriculture; Environment and Sustainability; Geography; Urban Studies","en","book","Routledge - Taylor & Francis Group","978-0-3678-1604-9","","","","","","","","","History, Form & Aesthetics","","",""
"uuid:3fda2b63-8f7e-4eb1-91e0-86023a418a60","http://resolver.tudelft.nl/uuid:3fda2b63-8f7e-4eb1-91e0-86023a418a60","The role of Dutch civil engineering in modern port planning in Japan (1870s–1890s)","Iwamoto, K. (National Institute for Land and Infrastructure Management); Hein, C.M. (TU Delft History, Form & Aesthetics)","","2021","In the mid-nineteenth century, civil engineering and technological innovation began to play a major role in the modernization and westernization of Japan. From the 1870s to the 1890s, Dutch civil engineers worked with Japanese practitioners on the design of Japanese ports, a key starting point for urban development. This article explores the role of port and port city planning by Dutch civil engineers on the development of Japanese engineering and planning practice following modern construction methods and technology. It explores the degree to which port and water planning proposals that were associated with foreign forces influenced the development of civil engineering-inspired urban planning practice in Japan. The article examines three case studies of port planning: Nobiru, Mikuni and Yokohama. It shows that comprehensive planning proposals by the Dutch engineers, who combined water management and the construction of port basins and breakwaters with city development, were only partially implemented because they were not aligned with Japanese natural and technical conditions. Instead, Japanese professionals stripped the proposals of the urban context and adopted engineering technology. The fascine mattress technique for breakwaters and imported steam dredging machines became key elements for the construction of basins and the maintenance of modern port function.","Civil engineering; Dutch engineers; fascine mattress; Port City planning; port planning; Urban Planning","en","journal article","","","","","","","","","","","History, Form & Aesthetics","","",""
"uuid:7f98f3d8-bebc-4927-8b5d-d70c84bfa04c","http://resolver.tudelft.nl/uuid:7f98f3d8-bebc-4927-8b5d-d70c84bfa04c","A virtual coach for low-literates to practice societal participation","Schouten, D.G.M. (TU Delft Interactive Intelligence)","Neerincx, M.A. (promotor); Cremers, A.H.M. (copromotor); Delft University of Technology (degree granting institution)","2020","This thesis presents the research, design, and evaluation of the learning support system VESSEL: Virtual Environment to Support the Societal participation Education of Low-literates. The project was started from the premise that people of low literacy in the Netherlands participate in society less often and less effectively than literate people do: Their lower ability to read, write, speak, and understand the Dutch language hampers their ability to independently be part of society. Our goal was to create learning support prototypes with a re-usable design rationale, aimed at helping these people of low literacy learn to improve their societal participation. To achieve this, low-literate learners participated throughout the entire design process, ensuring that we addressed their wants and needs with regard to learning and the perceived shortcomings of existing learning materials and kept in mind their skills and capabilities in order to ensure effective learning. Particularly, we investigated the possible ways that digital learning, Virtual Learning Environments (VLE), and Embodied Conversational Agents (ECA) could help fulfill the societal participation needs of this target group. We used the Socio-Cognitive Engineering (SCE) methodology to organize and structure this research, distinguishing the foundation, specification and evaluation of the VESSEL design. Two studies provided a grounded foundation for VESSEL, which was refined and worked out into three subsequent studies that provided the consequential design specifications and prototype evaluations (all prototypes have been tested with a human ’Wizard of Oz’ simulating VESSEL functionality).","Societal participation; Low-literacy; Virtual learning environment; Socio-Cognitive Engineering; Requirements engineering; Qualitative methods","en","doctoral thesis","","978-94-6423-079-6","","","","","","","","","Interactive Intelligence","","",""
"uuid:12393b11-a4c3-4697-8757-2b2dbc1291ec","http://resolver.tudelft.nl/uuid:12393b11-a4c3-4697-8757-2b2dbc1291ec","Combined gas engine-solid oxide fuel cell systems for marine power generation","Sapra, H.D. (TU Delft Ship Design, Production and Operations)","Hopman, J.J. (promotor); de Vos, P. (copromotor); Delft University of Technology (degree granting institution)","2020","Modern marine diesel engines operating on conventional marine fuels are unable to further reduce the adverse impact of ship emissions on the environment. Integration of a solid oxide fuel cell (SOFC) and internal combustion engine (ICE) equipped with an underwater exhaust (UWE) can provide the opportunity for mitigating ship emissions and improving energy efficiency. However, numerous integrated system variables such as fuel utilization, engine fuel composition, load-sharing etc. can significantly impact SOFC and ICE operation and, therefore, affect the feasibility and performance of the SOFC-ICE power plant. Moreover, presence of high and fluctuating back pressure due to an UWE can negatively impact engine operation and its performance limits. By investigating these challenges and more, the research presented in this dissertation aims to pave the way for the next generation of extremely efficient prime movers onboard ships, operating on alternative marine fuels, with ultra-low emissions.","Solid oxide fuel cells; Internal combustion engines; Underwater exhaust systems; Marine power generation; Alternative fuels; System integration; Combustion; Experiments andModelling and simulations","en","doctoral thesis","","978-94-6421-149-8","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:dfcd6e6b-cb63-4d64-98de-194b419d3cd3","http://resolver.tudelft.nl/uuid:dfcd6e6b-cb63-4d64-98de-194b419d3cd3","Selecting third-party libraries: The practitioners' perspective","Larios Vargas, E. (TU Delft Software Engineering; Software Improvement Group); Aniche, Maurício (TU Delft Software Engineering); Treude, Christoph (University of Adelaide); Bruntink, Magiel (Software Improvement Group); Gousios, G. (TU Delft Software Engineering)","Devanbu, Prem (editor); Cohen, Myra (editor); Zimmermann, Thomas (editor)","2020","The selection of third-party libraries is an essential element of virtually any software development project. However, deciding which libraries to choose is a challenging practical problem. Selecting the wrong library can severely impact a software project in terms of cost, time, and development effort, with the severity of the impact depending on the role of the library in the software architecture, among others. Despite the importance of following a careful library selection process, in practice, the selection of third-party libraries is still conducted in an ad-hoc manner, where dozens of factors play an influential role in the decision.
In this paper, we study the factors that influence the selection process of libraries, as perceived by industry developers. To that aim, we perform a cross-sectional interview study with 16 developers from 11 different businesses and survey 115 developers that are involved in the selection of libraries. We systematically devised a comprehensive set of 26 technical, human, and economic factors that developers take into consideration when selecting a software library. Eight of these factors are new to the literature. We explain each of these factors and how they play a role in the decision. Finally, we discuss the implications of our work to library maintainers, potential library users, package manager developers, and empirical software engineering researchers.","APIs; Empirical software engineering; Library adoption; Library selection; Software libraries","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Software Engineering","","",""
"uuid:33c7fc94-50cc-4b3f-be18-5439a9e29b43","http://resolver.tudelft.nl/uuid:33c7fc94-50cc-4b3f-be18-5439a9e29b43","Tightly Focused Spot Shaping and its Applications in Optical Imaging and Trapping","Meng, P. (TU Delft ImPhys/Optics)","Urbach, Paul (promotor); Pereira, S.F. (promotor); Delft University of Technology (degree granting institution)","2020","The Rayleigh criterion explains the diffraction limit and provides guidance for improving the performance of an imaging system namely by decreasing the wavelength of the illumination and/or increasing the aperture (NA) of the objective lens. If the wavelength and NA are set, is it possible to improve the spatial resolution further? This question motivates the research work of this thesis. Polarization is an important property of light and it can not be ignored in a tightly focusing system. It is demonstrated both theoretically and experimentally that radially polarized light can produce a sharper focal spot in a high NA focusing system because of the tight longitudinal field component. Based on this, in this thesis, we start our investigation on the unique focusing properties of the radially polarized beam with the vectorial diffraction theory. We show that the amplitude of the focal field can be shaped by engineering the pupil field of the radially polarized beam. The shaped focal spot is smaller than the unmodulated one, which can be used to improve the resolution of optical systems. Here, we consider a confocal scanning imaging system, offering several advantages over conventional widefield microscopy. In the simulation, longitudinal electric dipoles are regarded as the objects to make the full use of the optimized longitudinal component. An experimental proof is also given, showing that higher spatial resolution can be achieved when the modulated radially polarized light is applied in the confocal imaging set-up as compared to the non-modulated case. Radially polarized light can be obtained with a liquid crystal based polarization convertor, starting with a linearly polarized beam. Amplitude modulation of the pupil such as the annular pupil field and the designed pupil field where the amplitude increases gradually with the radius can be realized with a spatial light modulator (SLM). The substrate is essential for supporting the sample to be imaged. Usually, the material of the substrate is glass. In the near field, when the object interacts with the light field, it may produce evanescent waves which decays very quickly and has little influence on the imaging. However, the evanescent wave carries higher spatial frequency than the propagating wave. A well designed substrate with a thin TiOኼ layer on top can enhance the evanescent wave in the near field. The enhanced field transfers to a propagating wave with the help of the object deposited on the substrate and it can be detected in the far field. The principle can be explained with a dipole model, and simulated using nanospheres. It is demonstrated that the designed structure helps to improve the imaging quality including contrast and resolution. In addition, such sample model can be combined with other imaging techniques, e.g. confocal scanning microscopy, widefield imaging system, etc. Besides amplitude and polarization, focal fields can also be shaped in phase. Unlike the specific radially or azimuthally polarized vector beam, the cylindrical vector beam is a more general form. The focusing properties and the spin-orbit interacitions of cylindrical vector vortex beams in high NA focusing systems are theoretically studied. An absorptive nanosphere can be trapped at the hot-spot of the focused field, even when the field has its axial symmetry broken. The analysis on the influence of parameters such as the initial phase of the vortex beam, the topological charge, or the size and the material of the trapping sphere on the interplay between spin and angular momentum may be helpful for optical trapping, particle transport and super-resolution.","super-resolution imaging; pupil engineering; optical trapping; angular momenta","en","doctoral thesis","","978-94-6416-164-9","","","","","","","","","ImPhys/Optics","","",""
"uuid:446183ec-7974-46d9-a23b-bdcd0ffcde00","http://resolver.tudelft.nl/uuid:446183ec-7974-46d9-a23b-bdcd0ffcde00","Systematic Design Methodology for Prognostic and Health Management Systems to Support Aircraft Predictive Maintenance","Li, R. (TU Delft Air Transport & Operations)","Hoekstra, J.M. (promotor); Verhagen, W.J.C. (copromotor); Delft University of Technology (degree granting institution)","2020","With the rapid development in the past century, the air transport network has become one of the most important infrastructure networks for both the domestic and global economy. Within an airline, the maintenance area is responsible for planning and executing all preventive actions required to meet safety standards including maintenance tasks, etc. for each aircraft, demanding skilled jobs, e.g., aircraft mechanics, avionics systems experts, electricians, cabin experts. Aircraft maintenance concerns the maintenance, repair, and overhaul (MRO), inspection or modification to retain an aircraft and its aircraft systems, components and structures in an airworthy condition. A variety of strategies are available to guide determination, planning, and execution of appropriate maintenance actions for given capital assets. These include Condition-Based Maintenance (CBM), where the detection of an abnormal condition directly triggers a maintenance task, and predictive maintenance, where the optimal maintenance interval is predicted based on condition, time, usage or loads.","Aircraft Predictive Maintenance; Prognostic and Health Management; DesignMethodology; System Engineering; Remaining useful life","en","doctoral thesis","","978-94-6366-318-2","","","","","","","","","Air Transport & Operations","","",""
"uuid:11fc3020-2e13-4825-92ca-d4c9f7fd6815","http://resolver.tudelft.nl/uuid:11fc3020-2e13-4825-92ca-d4c9f7fd6815","Rational Design of Afterglow and Storage Phosphors","Lyu, T. (TU Delft RST/Luminescence Materials)","Dorenbos, P. (promotor); Delft University of Technology (degree granting institution)","2020","In this thesis, we have studied two types of charge carrier capturing and detrapping processes: (a) electron capturing and electron liberation; (b) hole
capturing and hole liberation. Both the (a) and (b) processes can be utilized for the rational design of afterglow and storage phosphors in different compounds.","afterglow; storage phosphor; charge carrier trapping processes; trap depth engineering; lanthanides; energy storage; Bi2+; Bi3+","en","doctoral thesis","","978-94-6380-906-1","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:4b1516b7-184a-4854-95fe-12bf052d4402","http://resolver.tudelft.nl/uuid:4b1516b7-184a-4854-95fe-12bf052d4402","A specialised delivery system for stratospheric sulphate aerosols: design and operation","Janssens, M. (Student TU Delft); de Vries, I. E. (Stockholm University); Hulshoff, S.J. (TU Delft Aerodynamics)","","2020","Temporary stratospheric aerosol injection (SAI) using sulphate compounds could help to mitigate some of the adverse and irreversible impacts of global warming. Among the risks and uncertainties of SAI, the development of a delivery system presents an appreciable technical challenge. Early studies indicate that specialised aircraft appear the most feasible (McClelan et al., Aurora Flight Sciences, 2010; Smith and Wagner, Environ Res Lett 13(12), 2018). Yet, their technical design characteristics, financial cost of deployment, and emissions have yet to be studied in detail. Therefore, these topics are examined in this two- part study. This first part outlines a set of injection scenarios and proposes a detailed, feasible aircraft design. Part 2 considers the resulting financial cost and equivalent CO2 emissions spanned by the scenarios and aircraft. Our injection scenarios comprise the direct injection of H2SO4 vapour over a range of possible dispersion rates and an SO2 injection scenario for comparison. To accommodate the extreme demands of delivering large payloads to high altitudes, a coupled optimisation procedure is used to design the system. This results in an unmanned aircraft configuration featuring a large, slender, strut-braced wing and four custom turbofan engines. The aircraft is designed to carry high-temperature H2SO4, which is evaporated prior to injection into a single outboard engine plume. Optimised flight profiles are produced for each injection scenario, all involving an initial climb to an outgoing dispersion leg at 20 km altitude, followed by a return dispersion leg at a higher altitude of 20.5 km. All the scenarios considered are found to be technologically and logistically attainable. However, the results demonstrate that achieving high engine plume dispersion rates is of principal importance for containing the scale of SAI delivery systems based on direct H2SO4 injection, and to keep these competitive with systems based on SO2 injection.","Climate engineering; Solar geoengineering; Solar radiation management; Specialised aircraft; Stratospheric sulphate aerosol injection; Technological implementation","en","journal article","","","","","","","","","","","Aerodynamics","","",""
"uuid:d9dfd7ba-7a5b-48d1-927f-fb73248b7a93","http://resolver.tudelft.nl/uuid:d9dfd7ba-7a5b-48d1-927f-fb73248b7a93","A Miniaturized EHT Platform for Accurate Measurements of Tissue Contractile Properties","Dostanic, M. (TU Delft Electronic Components, Technology and Materials); Stein, Jeroen (Leiden University Medical Center); Windt, Laura (Leiden University Medical Center); van Meer, Berend (Leiden University Medical Center); Bellin, Milena (Leiden University Medical Center; Università degli Studi di Padova); Orlova, Valeria (Leiden University Medical Center); Mastrangeli, Massimo (TU Delft Electronic Components, Technology and Materials); Mummery, Christine (Leiden University Medical Center); Sarro, Pasqualina M (TU Delft Electronic Components, Technology and Materials)","","2020","We present a wafer-scale fabricated, PDMS-based platform for culturing miniaturized engineered heart tissues (EHTs) which allows highly accurate measurements of the contractile properties of these tissues. The design of the platform is an anisometrically downscaled version of the Heart-Dyno system, consisting of two elastic micropillars inside an elliptic microwell with volume ranging from 3 down to 1μL which supports EHT formation. Size downscaling facilitates fabrication of the platform and makes it compatible with accurate and highly reproducible batch wafer-scale processing; furthermore, downscaling reduces the cost of cell cultures and increases assay throughput. After fabrication, the devices were characterized by nanoindentation to assess the mechanical properties of the pillars and transferred to 96-well plates for cell seeding. Regardless the size of the platform, cell seeding resulted in successful formation of EHTs and all tissues were functionally active (i.e. showed cyclic contractions). The precise characterization of the stiffness of the micropillars enabled accurate measurements of the contractile forces exerted by the cardiac tissues through optical tracking of micropillar displacement. The miniature EHT platforms described in this paper represent a proper microenvironment for culturing and studying EHTs.","Engineered heart tissue; microfabrication; nanoindentation; organs-on-chip; pluripotent stem cells","en","journal article","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:375bf549-f2a2-49a7-8d3d-a4489a579f4c","http://resolver.tudelft.nl/uuid:375bf549-f2a2-49a7-8d3d-a4489a579f4c","The Adoption of JavaScript Linters in Practice: A Case Study on ESLint","Tómasdóttir, Kristín (Student TU Delft); Aniche, Maurício (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology)","","2020","A linter is a static analysis tool that warns software developers about possible code errors or violations to coding standards. By using such a tool, errors can be surfaced early in the development process when they are cheaper to fix. For a linter to be successful, it is important to understand the needs and challenges of developers when using a linter. In this paper, we examine developers' perceptions on JavaScript linters. We study why and how developers use linters along with the challenges they face while using such tools. For this purpose we perform a case study on ESLint, the most popular JavaScript linter. We collect data with three different methods where we interviewed 15 developers from well-known open source projects, analyzed over 9,500 ESLint configuration files, and surveyed 337 developers from the JavaScript community. Our results provide practitioners with reasons for using linters in their JavaScript projects as well as several configuration strategies and their advantages. We also provide a list of linter rules that are often enabled and disabled, which can be interpreted as the most important rules to reason about when configuring linters. Finally, we propose several feature suggestions for tool makers and future work for researchers.","ASATs; Static analysis tools; empirical software engineering; eslint; javascript linters; linters","en","journal article","","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:ba9de40f-4981-43d1-adcb-b9a2f3224444","http://resolver.tudelft.nl/uuid:ba9de40f-4981-43d1-adcb-b9a2f3224444","Investigating Severity Thresholds for Test Smells","Spadini, D. (TU Delft Software Engineering); Schvarcbacher, Martin (Universiteit van Amsterdam); Oprescu, Ana (Universiteit van Amsterdam); Bruntink, Magiel (Software Improvement Group); Bacchelli, A. (TU Delft Software Engineering)","","2020","Test smells are poor design decisions implemented in test code, which can have an impact on the effectiveness and maintainability of unit tests. Even though test smell detection tools exist, how to rank the severity of the detected smells is an open research topic. In this work, we aim at investigating the severity rating for four test smells and investigate their perceived impact on test suite maintainability by the developers. To accomplish this, we first analyzed some 1,500 open-source projects to elicit severity thresholds for commonly found test smells. Then, we conducted a study with developers to evaluate our thresholds. We found that (1) current detection rules for certain test smells are considered as too strict by the developers and (2) our newly defined severity thresholds are in line with the participants' perception of how test smells have an impact on the maintainability of a test suite. Preprint [https://doi.org/10.5281/zenodo.3744281], data and material [https://doi.org/10.5281/zenodo.3611111].","Empirical Software Engineering; Software Testing; Test Smells","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Software Engineering","","",""
"uuid:f103447a-46a2-4653-91a2-a943e1b9c089","http://resolver.tudelft.nl/uuid:f103447a-46a2-4653-91a2-a943e1b9c089","Bar pattern and sediment sorting in a channel contraction/expansion area: Application to the Loire River at Bréhémont (France)","Cordier, Florian (Laboratoire d’Hydraulique Saint-Venant; EDF R&D LNHE - Laboratoire National d’Hydraulique et Environnement); Tassi, Pablo (Laboratoire d’Hydraulique Saint-Venant; EDF R&D LNHE - Laboratoire National d’Hydraulique et Environnement); Claude, Nicolas (EDF R&D LNHE - Laboratoire National d’Hydraulique et Environnement); Crosato, A. (TU Delft Environmental Fluid Mechanics; IHE Delft Institute for Water Education); Rodrigues, Stéphane (UMR CNRS 7324 CITERES & Ecole Polytechnique de l’Université de Tours (Polytech Tours)); Pham Van Bang, Damien (INRS-ETE, Quebec)","","2020","Bars are large sediment deposits alternating with deeper areas that arise from alluvial river bed instability and forcing. The present study aimed at investigating the combined influence of flow and longitudinal width variations on the co-evolution between bar pattern and sediment sorting in a sandy-gravel river reach. To this goal, a fully non-linear 2D numerical model was developed to reproduce the morphodynamic behavior of bars in a reach of the Loire River consisting in a typical channel expansion/contraction. Numerical results showed that varying water discharge promoted a competition between low and high bar modes: i.e., from alternate to multiple bar patterns. Low bar modes were associated with coarse sediment over bar tops and fine sediment in pools, and this sorting pattern was inverted for higher bar modes. Surface sediment was coarser and the degree of sediment sorting was greater after periods of low than high flow. Due to high sediment mobility, sediment sorting did not significantly modify bar morphodynamics.","Alluvial bar; Fluvial engineering; Fluvial morphodynamics; Heterogeneous sediment; Numerical modeling; Sediment transport","en","journal article","","","","","","Accepted author manuscript","","2022-05-03","","","Environmental Fluid Mechanics","","",""
"uuid:5c5c8932-5857-4b94-8702-d1dd0fa417b6","http://resolver.tudelft.nl/uuid:5c5c8932-5857-4b94-8702-d1dd0fa417b6","Simulation-based education involving online and on-campus models in different European universities","Campos, Neila (Universitat Oberta de Catalunya, Barcelona); Nogal Macho, M. (TU Delft Integral Design & Management); Caliz, Cristina (Euncet Business School, Terrassa); Juan, Angel A. (Universitat Oberta de Catalunya, Barcelona)","","2020","Simulation-based education (SE) refers to the use of simulation software, tools, and serious games to enrich the teaching and learning processes. Advances in both computer hardware and software allow for employing innovative methodologies that make use of SE tools to enhance the learning experience. Moreover, thanks to the globalisation of e-learning practices, these educational experiences can be made available to students from different geographical regions and universities, which promotes the development of international and inter-university cooperation in education. This paper provides a review of recent works in the SE subject, with a focus on the areas of engineering, science, and management. It also discusses some experiences in SE involving different European universities and learning models. Finally, it also points out open challenges as well as noticeable trends.","E-learning; Engineering education; Higher education; Simulation-based education","en","journal article","","","","","","","","","","","Integral Design & Management","","",""
"uuid:680dd908-1669-4411-9032-b3514399a0b9","http://resolver.tudelft.nl/uuid:680dd908-1669-4411-9032-b3514399a0b9","Understanding the Working Time of Developers in IT Companies in China and the United States","Zhang, Jiayun (Fudan University); Chen, Yang (Fudan University); Gong, Qingyuan (Fudan University); Ding, Aaron Yi (TU Delft Information and Communication Technology); Xiao, Yu (Aalto University); Wang, Xin (Fudan University); Hui, Pan (The Hong Kong University of Science and Technology)","","2020","We identified three temporal patterns shown in commit activities among Chinese and American companies and found that Chinese businesses are more likely to follow long work hours than American ones. We also conducted a survey on the trends of, reasons for, and results of overtime work. Our study could provide references for developers to choose workplaces and for companies to make regulations.","China; Companies; GitHub; IT company; Moon; overtime; Rhythm; Social network services; Software; Software engineering; Time-frequency analysis; United States; working time of developers","en","journal article","","","","","","","","","","","Information and Communication Technology","","",""
"uuid:1afe535c-0689-42ab-b3de-94c985eeb37d","http://resolver.tudelft.nl/uuid:1afe535c-0689-42ab-b3de-94c985eeb37d","Optimisation of Complex Geometry High-Rise Buildings based on Wind Load Analysis","Estrado, Erron (Student TU Delft); Turrin, M. (TU Delft Design Informatics); Eigenraam, P. (TU Delft Structural Design & Mechanics)","Chronis, Angelos (editor); Wurzer, Gabriel (editor); Lorenz, Wolfgang E. (editor); Herr, Christiane M. (editor); Pont, Ulrich (editor); Cupkova, Dana (editor); Wainer, Gabriel (editor)","2020","Wind analysis for the structure of buildings is a challenging process. The increasing strength and frequency of wind events due to climate change only add higher demands. In addition, high-rise buildings are growing in number and include many of unconventional shape. Current methods used in practice for calculating structural wind response either do not account for these geometries, such as the Eurocode or are prohibitively time-consuming and expensive, such as physical wind tunnel tests and complex Computational Fluid Dynamics simulations. As such, wind loads are usually only considered towards the end of design. This paper presents the development of a computational method to analyse the effect of wind on the structural behaviour of a 3D building model and optimise the external geometry to reduce those effects at an early design phase. It combines Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA), and an Optimisation algorithm. This allows it to be used in an early design stage for performance-based design exploration in complement to the more traditional late-stage methods outlined above. The method was implemented into a rapid and easy to use computational tool by combining existing plugins in Grasshopper into a single script that can be used in practice on complex shaped parametric high-rise building models. After developing the method and testing the timeliness and precision of the CFD, and FEA portions on case study buildings, the tool was able to output an optimal geometry as well as a database of improved geometric options with their corresponding performance for the wind loading allowing
for performance-based decision-making in the early design phase.","Computational Fluid Dynamics; Optimisation; Finite Element Analysis; Wind engineering; Parametric design; Computational design","en","conference paper","Society for Computer Simulation International (SCS)","","","","","","","","","","Design Informatics","","",""
"uuid:8cc98eeb-92e7-4939-a9c0-03bb050d3a56","http://resolver.tudelft.nl/uuid:8cc98eeb-92e7-4939-a9c0-03bb050d3a56","An integrated review of river bars for engineering, management and transdisciplinary research","Crosato, A. (TU Delft Environmental Fluid Mechanics; IHE Delft Institute for Water Education); Mosselman, E. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Deltares)","","2020","River training and river restoration often imply modifying the patterns and dimensions of bars, channels, and pools. Research since the 1980s has greatly advanced and matured our knowledge on the formation and behavior of river bars, thanks to field work, laboratory experiments, theoretical analyses, and numerical modelling by several research groups. However, this knowledge is not easily accessible to design engineers, river managers, and ecologists who need to apply it. This is mainly due to confusing differences in terminology as well as to difficult mathematical theories. Moreover, existing scientific publications generally focus on specific aspects, so an overall review of the findings and their applications is still lacking. In many cases, the knowledge achieved so far would allow minimizing hard engineering interventions and thus obtaining more natural rivers. We present an integrated review of the major findings of river bar studies. Our aim is to provide accessible state-of-the-art knowledge for nature-based bar management and successful river training and river restoration. To this end we review the results from analytical, numerical, experimental, and field studies, explain the background of bar theories, and discuss applications in river engineering and river restoration","Bar theory; River bars; River engineering; River restoration; River training","en","review","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:769d5ddc-550c-4800-ae42-9368cd64ea8a","http://resolver.tudelft.nl/uuid:769d5ddc-550c-4800-ae42-9368cd64ea8a","Natural architectures for tissue engineering and regenerative medicine","Honig, Floris (Universiteit Maastricht); Vermeulen, Steven (Universiteit Maastricht; Eindhoven University of Technology); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); de Boer, Jan (Eindhoven University of Technology); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics)","","2020","The ability to control the interactions between functional biomaterials and biological systems is of great importance for tissue engineering and regenerative medicine. However, the underlying mechanisms defining the interplay between biomaterial properties and the human body are complex. Therefore, a key challenge is to design biomaterials that mimic the in vivo microenvironment. Over millions of years, nature has produced a wide variety of biological materials optimised for distinct functions, ranging from the extracellular matrix (ECM) for structural and biochemical support of cells to the holy lotus with special wettability for self-cleaning effects. Many of these systems found in biology possess unique surface properties recognised to regulate cell behaviour. Integration of such natural surface properties in biomaterials can bring about novel cell responses in vitro and provide greater insights into the processes occurring at the cell-biomaterial interface. Using natural surfaces as templates for bioinspired design can stimulate progress in the field of regenerative medicine, tissue engineering and biomaterials science. This literature review aims to combine the state-of-the-art knowledge in natural and nature-inspired surfaces, with an emphasis on material properties known to affect cell behaviour.","(bio) materials; Biomimicry; Natural and nature-inspired surfaces; Regenerative medicine; Surface-cell interactions; Tissue engineering","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:51d85957-38e9-410d-9ad5-2f7b9fcddca3","http://resolver.tudelft.nl/uuid:51d85957-38e9-410d-9ad5-2f7b9fcddca3","Field experiments at three sites to investigate the effects of age on steel piles driven in sand","Carroll, R. (Norwegian Geotechnical Institute); Carotenuto, P. (Norwegian Geotechnical Institute); Dano, C. (Université Grenoble Alpes); Salama, I. (Université Grenoble Alpes); Silva, M. (Universidad Técnica Federico Santa María); Rimoy, S. (University of Dar Es Salaam); Gavin, Kenneth (TU Delft Geo-engineering); Jardine, R. (Imperial College London)","","2020","This paper investigates the influences that steel type, in situ soil properties, water table depth, pile diameter, roughness and driving procedures have on the ageing behaviour of piles driven in sand. Tension tests have been performed on 51 open-ended steel micro-piles, with 48 to 60 mm outside diameter, driven at well-established research sites at Larvik in Norway, Dunkirk in France and Blessington in Ireland to better understand the processes that control axial capacity set-up trends in the field. Mild steel, stainless and galvanised steel micro-piles were driven and left to age undisturbed for periods of between 2 h and 696 days before being subjected to first-time axial tension load tests. In addition to reporting and interpreting these experiments, further investigations of the sites' geotechnical profiles are reported, including new piezocone and seismic cone penetration soundings as well as laboratory tests. Integration with earlier ageing studies at the same sites with larger (340 to 508 mm outside diameter) open-ended steel piles driven to 7 to 20 m embedments and experiments that varied the piles' initial surface roughness shows that corrosion, pile scale, roughness, the bonding of soil particles and the driving process can all be highly significant. New insights are gained into the mechanisms that control the axial capacity of piles driven in sand.","model tests; offshore engineering; piles & piling; sands; time dependence","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-11-18","","","Geo-engineering","","",""
"uuid:1041ebe7-231c-49ce-ba9a-0e5c060c9953","http://resolver.tudelft.nl/uuid:1041ebe7-231c-49ce-ba9a-0e5c060c9953","Design and Experimental Evaluation of a Minimal, Innocuous Watermarking Strategy to Distinguish Near-Identical DNA and RNA Sequences","Boonekamp, F.J. (TU Delft BT/Industriele Microbiologie); Dashko, S. (TU Delft BT/Industriele Microbiologie); Duiker, Donna (Student TU Delft); Gehrmann, T. (Westerdijk Institute); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); den Ridder, M.J. (TU Delft OLD BT/Cell Systems Engineering); Pabst, Martin (TU Delft OLD BT/Cell Systems Engineering); Robert, Vincent (Westerdijk Institute); Abeel, T.E.P.M.F. (TU Delft Pattern Recognition and Bioinformatics); Postma, E.D. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Daran-Lapujade, P.A.S. (TU Delft BT/Industriele Microbiologie)","","2020","The construction of powerful cell factories requires intensive and extensive remodelling of microbial genomes. Considering the rapidly increasing number of these synthetic biology endeavors, there is an increasing need for DNA watermarking strategies that enable the discrimination between synthetic and native gene copies. While it is well documented that codon usage can affect translation, and most likely mRNA stability in eukaryotes, remarkably few quantitative studies explore the impact of watermarking on transcription, protein expression, and physiology in the popular model and industrial yeast Saccharomyces cerevisiae. The present study, using S. cerevisiae as eukaryotic paradigm, designed, implemented, and experimentally validated a systematic strategy to watermark DNA with minimal alteration of yeast physiology. The 13 genes encoding proteins involved in the major pathway for sugar utilization (i.e., glycolysis and alcoholic fermentation) were simultaneously watermarked in a yeast strain using the previously published pathway swapping strategy. Carefully swapping codons of these naturally codon optimized, highly expressed genes, did not affect yeast physiology and did not alter transcript abundance, protein abundance, and protein activity besides a mild effect on Gpm1. The markerQuant bioinformatics method could reliably discriminate native from watermarked genes and transcripts. Furthermore, presence of watermarks enabled selective CRISPR/Cas genome editing, specifically targeting the native gene copy while leaving the synthetic, watermarked variant intact. This study offers a validated strategy to simply watermark genes in S. cerevisiae.","differential RNA expression analysis; DNA and RNA watermarks; genome engineering; glycolysis; pathway swapping; Saccharomyces cerevisiae","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:477d2241-8d3f-4e9a-8882-a41a5aa47bb0","http://resolver.tudelft.nl/uuid:477d2241-8d3f-4e9a-8882-a41a5aa47bb0","Adaptive Laboratory Evolution and Reverse Engineering of Single-Vitamin Prototrophies in Saccharomyces cerevisiae","Perli, T. (TU Delft BT/Industriele Microbiologie); Moonen, Dewi P.I. (Student TU Delft); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2020","Quantitative physiological studies on Saccharomyces cerevisiae commonly use synthetic media (SM) that contain a set of water-soluble growth factors that, based on their roles in human nutrition, are referred to as B vitamins. Previous work demonstrated that in S. cerevisiae CEN. PK113-7D, requirements for biotin were eliminated by laboratory evolution. In the present study, this laboratory strain was shown to exhibit suboptimal specific growth rates when either inositol, nicotinic acid, pyridoxine, pantothenic acid, para-aminobenzoic acid (pABA), or thiamine was omitted from SM. Subsequently, this strain was evolved in parallel serial-transfer experiments for fast aerobic growth on glucose in the absence of individual B vitamins. In all evolution lines, specific growth rates reached at least 90% of the growth rate observed in SM supplemented with a complete B vitamin mixture. Fast growth was already observed after a few transfers on SM without myo-inositol, nicotinic acid, or pABA. Reaching similar results in SM lacking thiamine, pyridoxine, or pantothenate required more than 300 generations of selective growth. The genomes of evolved single-colony isolates were resequenced, and for each B vitamin, a subset of non-synonymous mutations associated with fast vitamin-independent growth was selected. These mutations were introduced in a non-evolved reference strain using CRISPR/Cas9-based genome editing. For each B vitamin, the introduction of a small number of mutations sufficed to achieve a substantially increased specific growth rate in non-supplemented SM that represented at least 87% of the specific growth rate observed in fully supplemented complete SM.","adaptive mutations; evolutionary engineering; media; nutritional requirements; prototrophy; reverse genetic analysis; Saccharomyces cerevisiae; vitamin biosynthesis","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:d0a69735-325f-48b0-aace-c6ff855e0ab7","http://resolver.tudelft.nl/uuid:d0a69735-325f-48b0-aace-c6ff855e0ab7","Exploiting the Diversity of Saccharomycotina Yeasts To Engineer Biotin-Independent Growth of Saccharomyces cerevisiae","Wronska, A.K. (TU Delft BT/Industriele Microbiologie); Haak, Meinske P. (Student TU Delft); Geraats, Ellen (Student TU Delft); Bruins Slot, Eva (Student TU Delft); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2020","Biotin, an important cofactor for carboxylases, is essential for all kingdoms of life. Since native biotin synthesis does not always suffice for fast growth and product formation, microbial cultivation in research and industry often requires supplementation of biotin. De novo biotin biosynthesis in yeasts is not fully understood, which hinders attempts to optimize the pathway in these industrially relevant microorganisms. Previous work based on laboratory evolution of Saccharomyces cerevisiae for biotin prototrophy identified Bio1, whose catalytic function remains unresolved, as a bottleneck in biotin synthesis. This study aimed at eliminating this bottleneck in the S. cerevisiae laboratory strain CEN.PK113-7D. A screening of 35 Saccharomycotina yeasts identified six species that grew fast without biotin supplementation. Overexpression of the S. cerevisiaeBIO1 (ScBIO1) ortholog isolated from one of these biotin prototrophs, Cyberlindnera fabianii, enabled fast growth of strain CEN.PK113-7D in biotin-free medium. Similar results were obtained by single overexpression of C. fabianii BIO1 (CfBIO1) in other laboratory and industrial S. cerevisiae strains. However, biotin prototrophy was restricted to aerobic conditions, probably reflecting the involvement of oxygen in the reaction catalyzed by the putative oxidoreductase CfBio1. In aerobic cultures on biotin-free medium, S. cerevisiae strains expressing CfBio1 showed a decreased susceptibility to contamination by biotin-auxotrophic S. cerevisiae This study illustrates how the vast Saccharomycotina genomic resources may be used to improve physiological characteristics of industrially relevant S. cerevisiaeIMPORTANCE The reported metabolic engineering strategy to enable optimal growth in the absence of biotin is of direct relevance for large-scale industrial applications of S. cerevisiae Important benefits of biotin prototrophy include cost reduction during the preparation of chemically defined industrial growth media as well as a lower susceptibility of biotin-prototrophic strains to contamination by auxotrophic microorganisms. The observed oxygen dependency of biotin synthesis by the engineered strains is relevant for further studies on the elucidation of fungal biotin biosynthesis pathways.","BIO1; biotin; Cyberlindnera fabianii; de novo synthesis; fungal biotin synthesis; metabolic engineering; oxygen requirement; oxygen-requiring enzyme; prototrophy; Saccharomyces cerevisiae; Saccharomycotina; vitamin B7","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:bc4d2ca5-591a-4157-8e4e-ded4b4e69ad5","http://resolver.tudelft.nl/uuid:bc4d2ca5-591a-4157-8e4e-ded4b4e69ad5","Reverse Engineering of existing reinforced concrete slab bridges","Harrewijn, T.L. (Student TU Delft; Royal HaskoningDHV); Vergoossen, R.P.H. (TU Delft Integral Design & Management; Royal HaskoningDHV); Lantsoght, E.O.L. (TU Delft Concrete Structures; Universidad San Francisco de Quito)","","2020","Most bridges in the Dutch infrastructure are built before 1985 and have experienced increasing traffic intensities and loads. On the other hand, the structural (design) codes have changed over the years. A frequently faced problem in practice is that the original design calculations and technical drawings of a large percentage of the existing bridge stock are unknown or lost. Therefore, the current capacity of the bridge is unknown. The currently used method to map the reinforcement dimensions and amounts in an existing bridge is by (X-ray) scanning. As an alternative, this work proposes Reverse Engineering of the existing bridges, by redoing (a correct) former bridge design with a known design year and load class as a starting point. Consequently, the Reverse Engineered bridge design can be assessed according to the current Eurocodes. A parametric study reveals different capacity margins in former structural bridge design than expected beforehand. Bending moment seems to be the governing failure mode where the main focus in literature laid on shear failure.","Reverse Engineering; existing bridges; former bridge design; capacity margin; assessment; parametric study; reinforced concrete","en","conference paper","","","","","","Accepted Author Manuscript","","2021-03-03","","","Integral Design & Management","","",""
"uuid:ff3c1dd4-3945-4b5f-90f0-d9954555a6c5","http://resolver.tudelft.nl/uuid:ff3c1dd4-3945-4b5f-90f0-d9954555a6c5","Before Responsible Innovation: Teaching Anticipation as a Competency for Engineers","Stone, T.W. (TU Delft Ethics & Philosophy of Technology; 4TU.Centre for Engineering Education); van Grunsven, J.B. (TU Delft Ethics & Philosophy of Technology; 4TU.Centre for Engineering Education); Marin, L. (TU Delft Ethics & Philosophy of Technology; 4TU.Centre for Engineering Education)","van der Veen, Jan (editor); van Hattum-Janssen, Natascha (editor); Järvinen, Hannu-Matti (editor); de Laet, Tinne (editor); ten Dam, Ineke (editor)","2020","This paper focuses on engineering ethics education utilizing Responsible Innovation (RI). As a forward-looking approach aiming to embed ethics within innovation practices, RI strives to align technology development with societal values. However, when teaching the concepts and methods of RI, we face two intertwined challenges. First, RI presupposes we can estimate the consequences of an innovation or design intervention, while evidence shows it is nearly impossible to fully predict the consequences of new technologies. RI acknowledges this by replacing an ambition to predict with a call to anticipate innovation-consequences. However, without a robust account of anticipation this merely kicks the can down the road. Second, RI seems to suggest that we know what is meant by a specific value (e.g., privacy, sustainability) and its relation to a specific technology. While such knowledge is key to an anticipatory perspective, values are often treated superficially and a historically in RI literature. To address these challenges, we argue that RI-focused education – and engineering ethics generally – should be fostering historically informed anticipation as a core competency. To do so, we will define and characterize a set of interrelated virtues essential for engaging in historically informed anticipation: moral sensitivity (an ability to identify values at stake), epistemic humility (an awareness of the limits of one’s understanding), and moral imagination (an ability to envision new perspectives and solutions). We suggest this can be cultivated via a novel teaching method that involves an in-depth historically informed normative analysis of a value technology dynamic (called a value-genealogy of technology).","Engineering ethics; Responsible Innovation; Anticipation; Virtue ethics","en","conference paper","SEFI","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:4f9ce0a5-5bf5-4b0d-8f71-967a5898998c","http://resolver.tudelft.nl/uuid:4f9ce0a5-5bf5-4b0d-8f71-967a5898998c","Finding the land, planting first seeds: lead user research in early stage design for intelligent ecosystems","Pannunzio, V. (TU Delft Methodologie en Organisatie van Design); Kleinsmann, M.S. (TU Delft Methodologie en Organisatie van Design); Falcão Duarte, C. (TU Delft Methodologie en Organisatie van Design); Snelders, H.M.J.J. (TU Delft Methodologie en Organisatie van Design)","","2020","This contribution explores the potential of lead user research for early-stage designing for intelligent ecosystems through a literature review and a single case study concerning a lead user research initiative on blood pressure monitoring. The results suggest advantages of executing lead user research in early-stage designing for intelligent ecosystems from the points of view envisioning broad initial ecosystem boundaries, developing first intelligence components, and overcoming research challenges related to technical issues.","healthcare design; open innovation; systems engineering (SE)","en","conference paper","Cambridge University Press","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:62e79abf-23d4-4944-84b6-d1de20dd96ae","http://resolver.tudelft.nl/uuid:62e79abf-23d4-4944-84b6-d1de20dd96ae","Structural analysis of Heinz Isler’s bubble shell","Eigenraam, P. (TU Delft Structural Design & Mechanics); Borgart, A. (TU Delft Structural Design & Mechanics); Chilton, John (University of Nottingham); Li, Qingpeng (Nanjing University)","","2020","This paper presents a detailed structural analysis of a bubble shell engineered by Heinz Isler. Through 3D scanning the geometry of this shell structure has become available to the authors. Structural analysis has not been possible before since the geometry of the shell was not available. The bubble shell was Isler’s most built type of shell. In the paperfirst the process of reverse engineering the geometry of the shell is described. Second, the effect of pre-stress in the edge beams is described. Third, the load distribution throughout the shell and the membrane behaviour relative to bending behaviour is assessed.","Finite element analysis; Heinz Isler; Physical models; Pre-stress; Reverse engineering; Shell behaviour; Shell structures; Structural analysis","en","journal article","","","","","","Accepted Author Manuscript","","2022-02-21","","","Structural Design & Mechanics","","",""
"uuid:5474f7e4-1a1c-4950-a63d-6960b847ba94","http://resolver.tudelft.nl/uuid:5474f7e4-1a1c-4950-a63d-6960b847ba94","OffSide: Learning to Identify Mistakes in Boundary Conditions","Arnar Briem, Jón (Student TU Delft); Smit, Jordi (Student TU Delft); Sellik, Hendrig (Student TU Delft); Rapoport, Pavel (Student TU Delft); Gousios, G. (TU Delft Software Engineering); Aniche, Maurício (TU Delft Software Engineering)","","2020","Mistakes in boundary conditions are the cause of many bugs in software. These mistakes happen when, e.g., developers make use of '<' or '>' in cases where they should have used '<=' or '>='. Mistakes in boundary conditions are often hard to find and manually detecting them might be very time-consuming for developers. While researchers have been proposing techniques to cope with mistakes in the boundaries for a long time, the automated detection of such bugs still remains a challenge. We conjecture that, for a tool to be able to precisely identify mistakes in boundary conditions, it should be able to capture the overall context of the source code under analysis. In this work, we propose a deep learning model that learn mistakes in boundary conditions and, later, is able to identify them in unseen code snippets. We train and test a model on over 1.5 million code snippets, with and without mistakes in different boundary conditions. Our model shows an accuracy from 55% up to 87%. The model is also able to detect 24 out of 41 real-world bugs; however, with a high false positive rate. The existing state-of-the-practice linter tools are not able to detect any of the bugs. We hope this paper can pave the road towards deep learning models that will be able to support developers in detecting mistakes in boundary conditions.","boundary testing; deep learning for software testing; machine learning for software engineering; machine learning for software testing; software engineering; software testing","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Software Engineering","","",""
"uuid:8224f2f6-c1d9-48c4-88ac-9e3399f9363a","http://resolver.tudelft.nl/uuid:8224f2f6-c1d9-48c4-88ac-9e3399f9363a","Coastal engineers embrace nature: Characterizing the metamorphosis in hydraulic engineering in terms of four continua","Slinger, J (TU Delft Policy Analysis; Rhodes University); Vreugdenhil, H.S.I. (TU Delft Policy Analysis; Deltares)","","2020","Hydraulic engineering infrastructures, such as reservoirs, dikes, breakwaters, and inlet closures, have significantly impacted ecosystem functioning over the last two centuries. Currently, nature-based solutions are receiving increasing attention in hydraulic engineering projects and research programs. However, there is a lack of reflection on the concomitant, fundamental changes occurring in the field of hydraulic engineering, and coastal engineering in particular, and what this could mean for sustainability. In this article, we signal the shift from conventional to ecosystem-based hydraulic engineering design and characterize this in terms of four continua: (i) the degree of inclusion of ecological knowledge, (ii) the extent to which the full infrastructural lifecycle is addressed, (iii) the complexity of the actor arena taken into account, and (iv) the resulting form of the infrastructural artefact. We support our arguments with two carefully selected, iconic examples from the Netherlands and indicate how the stretching ideals of ecosystem-based engineering could engender further shifts towards sustainability.","Building with Nature; Coastal and river engineering; Critical reflection; Ecosystem-based design; Impacts on nature and society; Infrastructure lifecycle; Multi-actor systems; Multifunctional flood defense; Nature-based solutions","en","journal article","","","","","","","","","","","Policy Analysis","","",""
"uuid:526b7c55-6ccb-46d8-bb79-2ccb084b62e2","http://resolver.tudelft.nl/uuid:526b7c55-6ccb-46d8-bb79-2ccb084b62e2","Teaching a hands-on course during corona lockdown: from problems to opportunities","Hut, R.W. (TU Delft Water Resources); Pols, C.F.J. (TU Delft ImPhys/Practicum support); Verschuur, D.J. (TU Delft ImPhys/Computational Imaging)","","2020","Teaching a hands- and minds-on course, in which feedback is essential in order to learn, is difficult, especially in times of COVID-19 where student progression cannot be monitored directly. During the lockdown period, the workshops of an undergraduate Design Engineering course had to be transferred to the home situation, which required a redesign of this course by the staff. It also provided new opportunities for students to adapt to this situation, which required extra creativity and problem-solving skills. The adapted workshops revealed conditions that enhance maker education. However, providing timely feedback required a substantial amount of time not anticipated for. We also report that short instruction videos seem to work much better than longer lectures or tedious materials. As we practice what we preach, we will evaluate the course and apply our design knowledge acquired over the years.","Design engineering; COVID-19; practical work","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:4340b55e-5eef-4e6a-97c3-d68da6861667","http://resolver.tudelft.nl/uuid:4340b55e-5eef-4e6a-97c3-d68da6861667","Studies on River Training","Mosselman, E. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)","","2020","This editorial regards a Special Issue of Water on river training. It introduces five papers in a framework of history, fundamentals, case studies and future. Four papers result from decades of experience with innovation, planning, design and implementation of river training works on rivers in Colombia, the Rhine branches in the Netherlands and the Brahmaputra-Jamuna River in Bangladesh. A fifth paper reviews the state-of-the-art in predicting and influencing the formation and behavior of river bars. The editorial argues that the future lies in more flexible river training, using a mix of innovative permanent structures and recurrent interventions such as dredging, sediment nourishment, vegetation management and low-cost temporary structures.","Brahmaputra-Jamuna River; Morphodynamics; Rhine River; River engineering; Riverbank erosion; Riverbank protection; Submerged vanes","en","contribution to periodical","","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:3585b229-84a0-4c26-b52f-e18c7a79782d","http://resolver.tudelft.nl/uuid:3585b229-84a0-4c26-b52f-e18c7a79782d","Questions for Data Scientists in Software Engineering: A Replication","Huijgens, H.K.M. (TU Delft Software Engineering); Rastogi, A. (TU Delft Software Engineering); Mulders, E.A. (TU Delft Electrical Engineering, Mathematics and Computer Science); Gousios, G. (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology)","Devanbu, Prem (editor); Cohen, Myra (editor); Zimmermann, Thomas (editor)","2020","In 2014, a Microsoft study investigated the sort of questions that data science applied to software engineering should answer. This resulted in 145 questions that developers considered relevant for data scientists to answer, thus providing a research agenda to the community. Fast forward to five years, no further studies investigated whether the questions from the software engineers at Microsoft hold for other software companies, including software-intensive companies with different primary focus (to which we refer as software-defined enterprises). Furthermore, it is not evident that the problems identified five years ago are still applicable, given the technological advances in software engineering. This paper presents a study at ING, a software-defined enterprise in banking in which over 15,000 IT staff provides in-house software solutions. This paper presents a comprehensive guide of questions for data scientists selected from the previous study at Microsoft along with our current work at ING. We replicated the original Microsoft study at ING, looking for questions that impact both software companies and software-defined enterprises and continue to impact software engineering. We also add new questions that emerged from differences in the context of the two companies and the five years gap in between. Our results show that software engineering questions for data scientists in the software-defined enterprise are largely similar to the software company, albeit with exceptions. We hope that the software engineering research community builds on the new list of questions to create a useful body of knowledge.","Data Science; Software Analytics; Software Engineering","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","Software Engineering","","",""
"uuid:f35ac84f-1fa3-43f9-9fb0-cc78546a4787","http://resolver.tudelft.nl/uuid:f35ac84f-1fa3-43f9-9fb0-cc78546a4787","Inertial sensors—applications and challenges in a nutshell","Seel, Thomas (Technical University of Berlin); Kok, M. (TU Delft Team Jan-Willem van Wingerden); McGinnis, Ryan S. (University of Vermont)","","2020","This editorial provides a concise introduction to the methods and applications of inertial sensors. We briefly describe the main characteristics of inertial sensors and highlight the broad range of applications as well as the methodological challenges. Finally, for the reader’s guidance, we give a succinct overview of the papers included in this special issue.","Accelerometers; Body area networks; Error modeling and calibration; Gyroscopes; Inertial motion tracking; Inertial sensors in health care and sports engineering; Inertial sensors in robotics and manufacturing; Inertial sensors in vehicle motion estimation and control; Localization and mapping; Machine learning applied to inertial sensor data; Magnetometers; Sensor fusion","en","contribution to periodical","","","","","","","","","","","Team Jan-Willem van Wingerden","","",""
"uuid:b5faf44a-ff52-4146-a2c2-ece485682ff0","http://resolver.tudelft.nl/uuid:b5faf44a-ff52-4146-a2c2-ece485682ff0","Testing the Validity and Reliability of an Instrument Measuring Engineering Students' Perceptions of Transversal Competency Levels","Leandro Cruz, M. (TU Delft Novel Aerospace Materials); van den Bogaard, M.E.D. (TU Delft Science Education and Communication); Saunders-Smits, Gillian (TU Delft Aerospace Structures & Materials); Groen, W.A. (TU Delft Aerospace Structures & Materials)","","2020","Contribution: This study reports on a reliable and valid instrument that measures engineering students' perceptions of their competency levels. A better understanding of students' needs in engineering curricula will support the development of engineering students' transversal competencies. Background: Prior research has investigated how engineering students perceive competency levels in transversal competencies. However, limitations in the competency definition, psychometric properties, and generalizability were found. Research questions: 1) What is the reliability and validity of the competency level instrument? and 2) what are the transversal competency level perceptions of engineering Bachelor and Master students? Methodology: A questionnaire consisting of 36 transversal competencies was designed based on an existing industry model and administered to 1087 engineering Bachelor and Master students from the University of Technology, The Netherlands. Validity and reliability were tested through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) and Cronbach's alpha. Findings: EFA resulted in five scales with reliable Cronbach's alpha values. CFA demonstrated a good model fit for the five-factor model with 25 items. Students perceived they are most competent in teamwork and lifelong learning competencies and less competent in entrepreneurial competencies.","Competency level measurement; engineering education; reliability; student perception; survey; transversal competencies and validity","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-05-01","","Aerospace Structures & Materials","Novel Aerospace Materials","","",""
"uuid:23ef0c4e-8466-4536-bed6-c02943a0298e","http://resolver.tudelft.nl/uuid:23ef0c4e-8466-4536-bed6-c02943a0298e","Ethical reflection or critical thinking? Overlapping competencies in engineering ethics education","Marin, L. (TU Delft Ethics & Philosophy of Technology)","van der Veen, Jan (editor); van Hattum-Janssen, Natascha (editor); Järvinen, Hannu-Matti (editor)","2020","Ethical reflection is considered to be an important competency for engineering ethics education. However it has no clear definition, which makes it difficult to effectively incorporate it into engineering ethics education. This paper proposes an operationalisation of ethical reflection into four learning goals which can help educators explicitly and systematically assess ethical reflection when using case-based exercises in the engineering ethics classroom. The four components were adapted from established educational approaches for critical thinking and then expanded to apply to normative propositions, the specific domain of ethical reflection.","Critical Thinking; case-based exercises; Engineering ethics; ethical reflection","en","conference paper","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:81f88b60-fcb4-434f-8948-2082c2350454","http://resolver.tudelft.nl/uuid:81f88b60-fcb4-434f-8948-2082c2350454","A product development approach advisor for navigating common design methods, processes, and environments","Stewart, Shelby (Stevens Institute of Technology); Giambalvo, Jack (Stevens Institute of Technology); Vance, Julia (Stevens Institute of Technology); Faludi, Jeremy (TU Delft Circular Product Design); Hoffenson, Steven (Stevens Institute of Technology)","","2020","Many different product development approaches are taught and used in engineering and management disciplines. These formalized design methods, processes, and environments differ in the types of projects for which they are relevant, the project components they include, and the support they provide users. This paper details a review of sixteen well-established product development approaches, the development of a decision support system to help designers and managers navigate these approaches, and the administration of a survey to gather subjective assessments and feedback from design experts. The included approaches—design thinking, systems thinking, total quality management, agile development, waterfall process, engineering design, spiral model, vee model, axiomatic design, value-driven design, decision-based design, lean manufacturing, six sigma, theory of constraints, scrum, and extreme programming—are categorized based on six criteria: complexity, guidance, phase, hardware or software applicability, values, and users. A decision support system referred to as the Product Development Approach Advisor (PD Advisor) is developed to aid designers in navigating these approaches and selecting an appropriate approach based on specific project needs. Next, a survey is conducted with design experts to gather feedback on the support system and the categorization of approaches and criteria. The survey results are compared to the original classification of approaches by the authors to validate and provide feedback on the PD Advisor. The findings highlight the value and limitations of the PD Advisor for product development practice and education, as well as the opportunities for future work.","Decision support system; Design methods; Design processes; Engineering design; Product development","en","journal article","","","","","","","","","","","Circular Product Design","","",""
"uuid:b7669039-da5e-407b-a6de-147bd140cea5","http://resolver.tudelft.nl/uuid:b7669039-da5e-407b-a6de-147bd140cea5","New data analysis methods for instrumented medium-scale monopile field tests","Burd, Harvey J. (University of Oxford); Beuckelaers, William J.A.P. (University of Oxford; Jan De Nul Group); Byrne, Byron W. (University of Oxford); Gavin, Kenneth (TU Delft Geo-engineering); Houlsby, Guy T. (University of Oxford); Igoe, David J.P. (Trinity College Dublin; University College Dublin); Jardine, Richard J. (Imperial College London); Martin, Christopher M. (University of Oxford); McAdam, Ross A. (University of Oxford)","","2020","The PISA Joint Industry Research Project was concerned with the development of improved design methods for monopile foundations in offshore wind applications. PISA involved large-scale pile tests in overconsolidated glacial till at Cowden, north-east England, and in dense, normally consolidated marine sand at Dunkirk, northern France. This paper describes the experimental set-up for pile testing, with unique features of load-application mechanisms and built-in fibre optic strain gauges. New procedures are described for the interpretation of pile loading data, and specifically for providing precise interpretation of pile displacements.","design; field instrumentation; model tests; offshore engineering; piles AND piling; soil/structure interaction","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:e8a32c88-32c5-4302-9621-b97028842392","http://resolver.tudelft.nl/uuid:e8a32c88-32c5-4302-9621-b97028842392","Modular impulsive green-monopropellant propulsion system for micro/nano satellites high-thrust orbital maneuvers (MIMPS-G)","Nosseir, A.E.S. (University of Pisa; Student TU Delft); Cervone, A. (TU Delft Space Systems Egineering); Pasini, A (University of Pisa)","","2020","Innovation in small-satellite modern space missions and applications require propulsion capabilities to enable active operations in orbit, such as formation flying, rendezvous operations, orbital altitude & inclination changes, and orbital transfers,– generally, operations demanding high-thrust impulsive maneuvers. In addition, Green-monopropellants are current state-of-the-art of liquid propellants for small satellites space propulsion due to their safety, stability, storability, relative design simplicity, and high performance. These facts were the motive behind the design of the Modular Impulsive Propulsion System– namely MIMPS-G – that utilizes Green-monopropellants and is a prospect solution for micro- and nano- spacecraft, particularly CubeSats, requiring a modular propulsion system for high-thrust impulsive orbital maneuvers. The baseline design is a standard 1U that can be expanded depending on the spacecraft size, required thrust level, and mission’s ΔV requirements. System analysis and preliminary design of MIMPS-G are discussed, and system architecture is presented. Different pressurization-systems are investigated – conventional and unconventional relative to small-satellites – emphasizing on autogenous-pressurization system utilizing micro electric pump, since the choice of the pressurization-system will further affect the propulsion system overall performance, onboard power consumption, and the spacecraft size optimization. A tradeoff study with regards to the performance and characteristics of suitable monopropellants, to be utilized by MIMPS-G, is carried out to give insights for system design and architecture possibilities, as well as future studies concerned with monopropellant propulsion systems for various classes of space propulsion. Finally, candidate propulsion system utilizing a 0.5 N thruster – designated as MIMPS-G500mN – is introduced elaborating system’s architecture, analysis, design, and CAD models. MIMPS-G500mN offers total impulse 퐼푡표푡 ≅ 850 to 1350 N.s per 1U or >3000 푁.푠 per 2U expanded-layout depending on used propellant, which makes the latter a modular expandable propulsion system suitable for Lunar missions. Comparative results of the propulsion system properties using different monopropellants are tabulated – focusing on alternatives for the highly stable Hydroxyl-ammonium nitrate (HAN-) based monopropellant AF-M315E, that is the state-of-art of green-monopropellants.","Liquid Rocket Engine; CubeSat; Small-satellites; Green-propellant; Monopropellant; Micro Electric Pump-feed; Multimode Propulsion System","en","conference paper","IAF/AIAA","","","","","Virtual/online event due to COVID-19 accepted author manuscript","","2021-01-01","","","Space Systems Egineering","","",""
"uuid:6dae743a-7b3c-42a0-9ec8-9fddc8b7d250","http://resolver.tudelft.nl/uuid:6dae743a-7b3c-42a0-9ec8-9fddc8b7d250","Autonomous multifunctional vehicle with integrated bio-inspired SMA actuated grasper","Changoski, Vasko (SS Cyril and Methodius University); Domazetovska, Simona (SS Cyril and Methodius University); Anachkova, Maja (SS Cyril and Methodius University); Jovanova, J. (TU Delft Transport Engineering and Logistics)","","2020","The space exploration activities are merging new technologies in order to develop systems challenged to achieve capabilities for high mission experience. Inspired by the numerous applications in space exploration, with the integration of shape memory alloys (SMAs), a 3D printed continuous All Terrain Grasper Transport (AT-GT) vehicle with implemented multi-locomotion grasper was created. In order to reduce failure of the mechanical system, the vehicle is equipped with SMA suspension and SMA tensioner of a pulley system with adaptable height able to achieve movement on a given trajectory and adjust to any terrain. SMA actuators provide controllable actuation based on the simplicity of their design and the shape memory effect. By using the advantages of the origami engineering, soft robotics and smart material implementation, a bio-inspired autonomous grasper was integrated on the AT-GT, capable of leaving the vehicle, grabbing an object and bringing it back to the vehicle. The concept development, the analytical models and the prototype including the benefits of the combined work of the vehicle and the grasper are presented.","Bio-inspired vehicle; Grasper; Multi-locomotion; Origami engineering; Smart materials actuation","en","conference paper","ASME","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-05-04","","","Transport Engineering and Logistics","","",""
"uuid:cc9f7491-0b07-4cca-9db4-340bf33837ac","http://resolver.tudelft.nl/uuid:cc9f7491-0b07-4cca-9db4-340bf33837ac","Current challenges and future opportunities of phage therapy","Pires, Diana P. (University of Minho); Martins Costa, A.R. (TU Delft BN/Stan Brouns Lab; Kavli institute of nanoscience Delft); Pinto, Graça (University of Minho); Meneses, Luciana (University of Minho); Azeredo, Joana (University of Minho)","","2020","Antibiotic resistance is a major public health challenge worldwide, whose implications for global health might be devastating if novel antibacterial strategies are not quickly developed. As natural predators of bacteria, (bacterio)phages may play an essential role in escaping such a dreadful future. The rising problem of antibiotic resistance has revived the interest in phage therapy and important developments have been achieved over the last years. But where do we stand today and what can we expect from phage therapy in the future? This is the question we set to answer in this review. Here, we scour the outcomes of human phage therapy clinical trials and case reports, and address the major barriers that stand in the way of using phages in clinical settings. We particularly address the potential of phage resistance to hinder phage therapy and discuss future avenues to explore the full capacity of phage therapy.","clinical trials; One-Health; phage cocktails; phage engineering; phage resistance; regulatory framework","en","review","","","","","","Accepted Author Manuscript","","2021-05-30","","","BN/Stan Brouns Lab","","",""
"uuid:fa8152bf-5d7d-408b-8e45-b611af7862fc","http://resolver.tudelft.nl/uuid:fa8152bf-5d7d-408b-8e45-b611af7862fc","The Effectiveness of Supervised Machine Learning Algorithms in Predicting Software Refactoring","Aniche, Maurício (TU Delft Software Engineering); Maziero, Erick (Universidade Federal de Lavras); Durelli, Rafael (Universidade Federal de Lavras); Durelli, Vinicius (Federal University of São João del-Rei)","","2020","Refactoring is the process of changing the internal structure of software to improve its quality without modifying its external behavior. Empirical studies have repeatedly shown that refactoring has a positive impact on the understandability and maintainability of software systems. However, before carrying out refactoring activities, developers need to identify refactoring opportunities. Currently, refactoring opportunity identification heavily relies on developers' expertise and intuition. In this paper, we investigate the effectiveness of machine learning algorithms in predicting software refactorings. More specifically, we train six different machine learning algorithms (i.e., Logistic Regression, Naive Bayes, Support Vector Machine, Decision Trees, Random Forest, and Neural Network) with a dataset comprising over two million refactorings from 11,149 real-world projects from the Apache, F-Droid, and GitHub ecosystems. The resulting models predict 20 different refactorings at class, method, and variable-levels with an accuracy often higher than 90 percent. Our results show that (i) Random Forests are the best models for predicting software refactoring, (ii) process and ownership metrics seem to play a crucial role in the creation of better models, and (iii) models generalize well in different contexts.","software refactoring; machine learning for software engineering; refactoring recommendation","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:c4b417ab-a88e-47e1-abf1-d4cad9daebf2","http://resolver.tudelft.nl/uuid:c4b417ab-a88e-47e1-abf1-d4cad9daebf2","Haptics: Science, Technology, Applications: 12th International Conference, EuroHaptics 2020, Leiden, The Netherlands, September 6–9, 2020, Proceedings","","Nisky, Ilana (editor); Hartcher-O'Brien, J. (editor); Wiertlewski, M. (editor); Smeets, Jeroen B J (editor)","2020","This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020.
The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility.
4 (RE = Y, Lu) with high charge carrier storage capacity","Lyu, T. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2020","Guided by vacuum referred binding energy (VRBE) diagrams, both the trapping and detrapping processes of electrons and holes are explored in the bismuth and lanthanide-doped LiRE(Si,Ge)O4 (RE = Y, Lu) family of compounds. The Tm3+ electron trap has been combined with the deep hole traps of Ln3+ (Ln = Ce, Tb, or Pr) or Bi3+ in LiLuSiO4. During the thermoluminescence readout, the electrons released from Tm2+ recombine with holes at Ln4+ and Bi4+ to produce typical Ln3+ 4f-4f or 5d-4f emission and Bi3+ A-band emission. The electron trap depth of lanthanide ions can be tuned by the choice of Ln3+ (Ln = Tm or Sm), and for fixed pair of Ln3+ and/or Bi3+ dopants like in LiLu1−xYxSiO4:0.01Ce3+,0.01Ln3+ and LiLu1−xYxSiO4:0.01Bi3+,0.01Sm3+ solid solutions, by adjusting x, resulting in the engineering of the VRBE at the conduction band bottom. The thermoluminescence (TL) intensity of the optimized LiLu0.5Y0.5SiO4:0.01Ce3+, 0.005Sm3+ is about 8.5 times higher than that of the commercial X-ray BaFBr(I):Eu2+ storage phosphor. By combining deep Eu3+ or Bi3+ electron traps with Ln3+ (Ln = Tb or Pr) or Bi3+, Ln3+ and Bi3+ appear to act as less deep hole capturing centres in LiLuSiO4. Here the recombination is achieved through hole liberation rather than the more commonly reported electron liberation. The holes are released from Ln4+ and Bi4+ to recombine with electrons at Eu2+ or Bi2+ to give characteristic Eu3+ 4f-4f and Bi3+ A-band emissions. The tailoring of Ln3+ and Bi3+ hole trap depths by crystal composition modulation is discussed in LiLu1−xYxSiO4 and LiLu0.25Y0.75Si1−yGeyO4:0.01Bi3+ solid solutions. The TL intensity of the optimized LiLu0.25Y0.75SiO4:0.01Bi3+ is ~4.4 times higher than that of the commercial BaFBr(I):Eu2+. Proof-of-concept information storage will be demonstrated with X-ray or UV-light charged LiLu0.5Y0.5SiO4:0.01Ce3+,0.01Sm3+ and LiLu0.25Y0.75SiO4:0.01Bi3+ phosphors dispersed in silicone gel imaging plates.","Bismuth; Energy conversion; Energy storage; Hole liberation; Trap engineering","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:b5701a38-aa2a-45f9-9357-44088e039af6","http://resolver.tudelft.nl/uuid:b5701a38-aa2a-45f9-9357-44088e039af6","Engineering Saccharomyces cerevisiae for Succinic Acid Production From Glycerol and Carbon Dioxide","Xiberras, Joeline (Jacobs University Bremen); Klein, Mathias (Jacobs University Bremen); de Hulster, A.F. (TU Delft BT/Industriele Microbiologie); Mans, R. (TU Delft BT/Industriele Microbiologie); Nevoigt, Elke (Jacobs University Bremen)","","2020","Previously, our lab replaced the endogenous FAD-dependent pathway for glycerol catabolism in S. cerevisiae by the synthetic NAD-dependent dihydroxyacetone (DHA) pathway. The respective modifications allow the full exploitation of glycerol’s higher reducing power (compared to sugars) for the production of the platform chemical succinic acid (SA) via a reductive, carbon dioxide fixing and redox-neutral pathway in a production host robust for organic acid production. Expression cassettes for three enzymes converting oxaloacetate to SA in the cytosol (“SA module”) were integrated into the genome of UBR2CBS-DHA, an optimized CEN.PK derivative. Together with the additional expression of the heterologous dicarboxylic acid transporter DCT-02 from Aspergillus niger, a maximum SA titer of 10.7 g/L and a yield of 0.22 ± 0.01 g/g glycerol was achieved in shake flask (batch) cultures. Characterization of the constructed strain under controlled conditions in a bioreactor supplying additional carbon dioxide revealed that the carbon balance was closed to 96%. Interestingly, the results of the current study indicate that the artificial “SA module” and endogenous pathways contribute to the SA production in a highly synergistic manner.","biodiesel; glycerol; metabolic engineering; NADH; succinic acid","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:eb9e1ea6-e094-4d47-8250-c57678d8f86a","http://resolver.tudelft.nl/uuid:eb9e1ea6-e094-4d47-8250-c57678d8f86a","Hydrogen-natural gas combustion in a marine lean-burn SI engine: A comparitive analysis of Seiliger and double Wiebe function-based zero–dimensional modelling","Sapra, H.D. (TU Delft Ship Design, Production and Operations); Godjevac, M. (Allseas Engineering); de Vos, P. (TU Delft Ship Design, Production and Operations); Van Sluijs, Wim (Pon Power Nederland); Linden, Youri (Student TU Delft); Visser, K. (TU Delft Ship Design, Production and Operations)","","2020","With increasingly stringent emission regulations, marine natural gas engines need to improve their performance. Various proven advantages of hydrogen-natural gas (H-NG) blends make them a promising enhanced fuel solution. Although modelling of H-NG combustion has been investigated before, mostly using CFD models, the literature on the modelling capabilities of Seiliger-based and Wiebe-based zero-dimensional (0-D) models is limited for H-NG combustion. Especially for the application of marine lean-burn spark-ignited (SI) engines. Therefore, the aim of this paper is to compare the capabilities of Seiliger-based and double Wiebe function-based 0-D models to capture H-NG combustion in a marine SI engine for different H-NG fuel blends, engine leaning (lean-burn operation) and engine loads. In this work, measurements on a turbocharged, SI marine natural gas engine were used to develop a heat release rate model, which was subsequently used as a basis for the Seiliger and double Wiebe function-based H-NG combustion characterization models. Results from the two combustion modelling approaches were compared for different H-NG fuel blends, engine leaning (lean-burn operation) and engine loads. The modelling results were also compared against engine measurements for different experimental conditions. This paper shows that the Seiliger modelling approach can be used to define different physical phenomenon in H-NG combustion, while accurately capturing the effects of hydrogen addition and engine leaning on the H-NG combustion process at varying engine loads. This research also found that the variations in late burn phase present in lean-burn NG and H-NG combustion can be captured using the double-Wiebe modelling approach, however, clear trends of the Wiebe combustion parameters for varying fuel blends and engine loads could not be identified to accurately capture the H-NG combustion process. Furthermore, Wiebe-based modelling approach produced larger errors in the estimations of work output and combustion heat for all test conditions.","Hydrogen-natural gas; Lean-burn combustion; Marine SI engine; Seiliger model; Wiebe model","en","journal article","","","","","","Accepted Author Manuscript","","2022-02-09","","","Ship Design, Production and Operations","","",""
"uuid:9f375f76-40ea-4e99-ae0e-6cd6000171a7","http://resolver.tudelft.nl/uuid:9f375f76-40ea-4e99-ae0e-6cd6000171a7","Ground response during offshore pile driving in a sandy slope","Lamens, Pascale (Royal Boskalis Westminster; Student TU Delft); Askarinejad, A. (TU Delft Geo-engineering); Sluijsmans, Robbin W. (Royal Boskalis Westminster); Feddema, Antoine (Volker Infra)","","2020","This paper presents an analysis of field measurements obtained during pile installation tests in a submerged sandy slope. The field test was performed in 2016 as part of the construction of a new sea lock in the Netherlands. Ground vibrations and excess pore pressures were to be limited in order to prevent damage to neighbouring locks and maintain slope stability. Geophones and piezometers were installed in the slope, at depth, and at various lateral distances from the pile axis. In the analysis, focus is placed on the installation of a tubular steel pile, which was subjected to both vibratory and impact driving. An assessment is made of some factors, such as driving equipment and pile tip penetration depth, affecting both the magnitude of ground vibration and its spatial and temporal characteristics. A similar analysis is conducted of the pore pressure measurements, with particular attention paid to the part of driving carried out in a homogeneous sand layer. Measured vibrations and excess pore pressures are compared to established attenuation relationships and published data, respectively. An approach is suggested in which the test results and interpretation may be used in assessing the potential implications of excess pore pressure development in the sand layer for slope stability.","Field instrumentation; Full-scale tests; Liquefaction; Offshore engineering; Piles & piling; Vibration","en","journal article","","","","","","Accepted Author Manuscript","","2020-09-10","","","Geo-engineering","","",""
"uuid:d51c74b9-83ab-4c6a-9267-04c1494730b1","http://resolver.tudelft.nl/uuid:d51c74b9-83ab-4c6a-9267-04c1494730b1","Total magnetic force on a ferrofluid droplet in microgravity","Romero-Calvo, Álvaro (University of Colorado; University of Seville); Cano-Gómez, Gabriel (University of Seville); Hermans, T.H.J. (TU Delft Physical and Space Geodesy); Parrilla Benítez, Lidia (University of Seville); Herrada Gutiérrez, Miguel Ángel (University of Seville); Castro-Hernández, Elena (University of Seville)","","2020","The formulation of the total force exerted by magnetic fields on ferrofluids has historically been a subject of intense debate and controversy. Although the theoretical foundations of this problem can now be considered to be well established, significant confusion still remains regarding the implementation of the associated expressions. However, the development of future applications in low-gravity environments is highly dependent on the correct modeling of this force. This paper presents a contextualized analysis of different proposed calculation procedures and validation in a space-like environment. Kinematic measurements of the movement of a ferrofluid droplet subjected to an inhomogeneous magnetic field in microgravity are compared with numerical predictions from a simplified physical model. Theoretical results are consistent with the assumptions of the model and show an excellent agreement with the experiment. The Kelvin force predictions are included in the discussion to exemplify how an incomplete modeling of the magnetic force leads to significant errors in the absence of gravity.","Ferrofluids; Magnetic mass transfer; Microgravity; Space engineering; Total magnetic force","en","journal article","","","","","","Accepted Author Manuscript","","2022-04-30","","","Physical and Space Geodesy","","",""
"uuid:3f922664-a402-449d-98de-bc201b38fa8e","http://resolver.tudelft.nl/uuid:3f922664-a402-449d-98de-bc201b38fa8e","Rubber-Oil Distillation Bottoms Blends as a New Recycling Solution for Bitumen Extension","Tarsi, G. (University of Bologna); Sangiorgi, C. (University of Bologna); Varveri, Aikaterini (TU Delft Pavement Engineering); Oliviero Rossi, C. (University of Calabria)","Raab, C. (editor)","2020","Environmental protection is also pursued by promoting the saving of oil reserves and the proper management of waste through a circular economy. Following this objective, the present study encourages the use of recycled and by-product materials for the production of bituminous binders. The powdered rubber (R) from end-of-life tyres and the re-refined engine oil bottom (REOB), i.e. the by-product of refining mineral waste oils, were used to replace a certain amount of standard bitumen. The experimental program aims to characterize the interaction between R and REOB in order to use them as virgin bitumen extenders. The multiple variables of the production process that may affect the R-REOB blends and in turn the binders’ final properties were evaluated. The R-REOB mixes were prepared by varying the type of REOB, the R content and the mixing temperature. The rheological analysis was performed by means of dynamic shear rheometer (DSR) tests with the aim to define the variables that strongly influence the response of the R-REOB compound. As a result of this preliminary study, the second phase will focus on extended bitumens that will be prepared considering some of the studied extenders.","Extended bitumen; Re-refined engine oil bottom; Rheology; Waste rubber","en","book chapter","SpringerOpen","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-12-20","","","Pavement Engineering","","",""
"uuid:a7a92e66-6189-4717-82d6-0ea9a3ad4d6e","http://resolver.tudelft.nl/uuid:a7a92e66-6189-4717-82d6-0ea9a3ad4d6e","Improving Industrially Relevant Phenotypic Traits by Engineering Chromosome Copy Number in Saccharomyces pastorianus","Gorter de Vries, A.R. (TU Delft BT/Industriele Microbiologie); Knibbe, E. (TU Delft BT/Industriele Microbiologie); van Roosmalen, Roderick (Student TU Delft); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); de la Torre, P. (TU Delft BT/Industriele Microbiologie); O’Herne, Stephanie F. (Student TU Delft); Vijverberg, Pascal A. (Student TU Delft); el Masoudi, Anissa (Student TU Delft); Brouwers, N. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2020","The lager-brewing yeast Saccharomyces pastorianus is a hybrid between S. cerevisiae and S. eubayanus with an exceptional degree of aneuploidy. While chromosome copy number variation (CCNV) is present in many industrial Saccharomyces strains and has been linked to various industrially-relevant traits, its impact on the brewing performance of S. pastorianus remains elusive. Here we attempt to delete single copies of chromosomes which are relevant for the production of off-flavor compound diacetyl by centromere silencing. However, the engineered strains display CNV of multiple non-targeted chromosomes. We attribute this unintended CCNV to inherent instability and to a mutagenic effect of electroporation and of centromere-silencing. Regardless, the resulting strains displayed large phenotypic diversity. By growing centromere-silenced cells in repeated sequential batches in medium containing 10% ethanol, mutants with increased ethanol tolerance were obtained. By using CCNV mutagenesis by exposure to the mitotic inhibitor MBC, selection in the same set-up yielded even more tolerant mutants that would not classify as genetically modified organisms. These results show that CCNV of alloaneuploid S. pastorianus genomes is highly unstable, and that CCNV mutagenesis can generate broad diversity. Coupled to effective selection or screening, CCNV mutagenesis presents a potent tool for strain improvement.","chromosome copy number stability; chromosome missegregation; lager beer brewing; Saccharomyces pastorianus; strain engineering","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:b9065219-7841-442d-8ea0-0d3473607254","http://resolver.tudelft.nl/uuid:b9065219-7841-442d-8ea0-0d3473607254","Development of spectral-phenological features for deep learning to understand Spartina alterniflora invasion","Tian, Jinyan (Capital Normal University); Wang, Le (University at Buffalo, State University of New York); Yin, Dameng (University at Buffalo, State University of New York); Li, Xiaojuan (Capital Normal University); Diao, Chunyuan (University of Illinois at Urbana-Champaign); Gong, Huili (Capital Normal University); Shi, Chen (Capital Normal University); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Ge, Yong (Chinese Academy of Sciences)","","2020","Invasive Spartina alterniflora (S. alterniflora), a native riparian species in the U.S. Gulf of Mexico, has led to serious degradation to the ecosystem and biodiversity as well as economic losses since it was introduced to China in 1979. Although multi-temporal remote sensing offers unique capability to monitor S. alterniflora over large areas and long time periods, three major hurdle exist: (1) in the coastal zone where S. alterniflora occupies, frequent cloud coverage reduces the number of available images that can be used; (2) prominent spectral variations exist within the S. alterniflora due to phonological variations; (3) poor spectral separability between S. alterniflora and its co-dominant native species is often presented in the territories where S. alterniflora intruded in. To articulate these questions, we proposed a new pixel-based phenological feature composite method (Ppf-CM) based on Google Earth Engine. The Ppf-CM method was brainstormed to battle the aforementioned three hurdles as the basic unit for extracting phonological feature is individual pixel in lieu of an entire image scene. With the Ppf-CM-derived phenological feature as inputs, we took a step further to investigate the performance of the latest deep learning method as opposed to that of the conventional support vector machine (SVM); Lastly, we strive to understand how S. alterniflora has changed its spatial distribution in the Beibu Gulf of China from 1995 to 2017. As a result, we found (1) the developed Ppf-CM method can mitigate the phonological variation and augment the spectral separability between S. alterniflora and the background species regardless of the significant cloud coverage in the study area; (2) deep learning, compared to SVM, presented better potentials for incorporating the new phenological features generated from the Ppf-CM method; and (3) for the first time, we discovered a S. alterniflora invasion outbreak occurred during 1996–2001.","Cloudy coastal zone; Deep learning; Google earth engine; Invasive species; Phenology; Remote sensing big data","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:7d162d6b-2b0b-438d-8ba4-94d26bff0a44","http://resolver.tudelft.nl/uuid:7d162d6b-2b0b-438d-8ba4-94d26bff0a44","Disposal and recycle economic assessment for aircraft and engine end of life solution evaluation","Zhao, X. (TU Delft Air Transport & Operations; Northwestern Polytechnical University); Verhagen, W.J.C. (TU Delft Air Transport & Operations; Royal Melbourne Institute of Technology University); Curran, R. (TU Delft Air Transport & Operations)","","2020","The present study proposes an economic indicator to support the evaluation of aircraft End of Life (EoL) strategies in view of the increasing demand with regards to aircraft decommissioning. This indicator can be used to evaluate the economic performance and to facilitate the trade-off studies among different strategies. First, Disposal and Recycle (D&R) scenarios related to stakeholders are investigated to identify the core concepts for the economic evaluation. Next, we extracted the aircraft D&R process from various real-life practices. In order to obtain the economic measure for the engineering process, a method of estimating the D&R cost and values are developed by integrating product, process and cost properties. This analysis is demonstrated on an averaged data set and two EoL aircraft cases. In addition, sensitivity analysis is performed to evaluate the impact of the D&R cost, residual value, and salvage value. Results show that the disassembly and dismantling of an aircraft engine possesses relatively more economic gains than that for the aircraft. The main factors influencing the proposed D&R economic indicator are the salvage value and D&R cost for economically efficient D&R cases. In addition, delaying the disposal and recycle process for EoL aircraft can lead to economically unfavorable solutions. The economic indicator combined with the evaluation methods is widely applicable for evaluations of engineering products EoL solutions, and implies a significant contribution of this research to decision making for such complex systems in terms sustainable policy.","Aircraft and aircraft engine Life Cycle Analysis (LCA); Aircraft disposal and recycle process; Disposal and recycle economic indicator; End of Life (EoL); Engineering cost and value analysis","en","journal article","","","","","","","","","","","Air Transport & Operations","","",""
"uuid:3e9e3694-f877-4711-8267-af7942018195","http://resolver.tudelft.nl/uuid:3e9e3694-f877-4711-8267-af7942018195","Prediction of acoustic noise and vibration of a 24/16 traction switched reluctance machine","Liang, Jianbin (McMaster University); Jiang, James W. (McMaster University); Callegaro, Alan Dorneles (McMaster University); Bilgin, Berker (McMaster University); Dong, J. (TU Delft DC systems, Energy conversion & Storage); Reeves, Debbie (MSC Software Corporation); Emadi, Ali (McMaster University)","","2020","This study presents a numerical modelling approach for the prediction of vibration and acoustic noise for a 24/16 traction switched reluctance machine (SRM). The numerical modelling includes the simulation of electromagnetic force in JMAG, the calculation of natural frequencies and the simulation of vibration and acoustic noise in ACTRAN. Considerations in the modelling of geometries, meshing and contacts of the 24/16 SRM are discussed to ensure the accuracy of the numerical simulation. Two-dimensional fast Fourier transform (FFT) is applied to the radial nodal force at the stator pole tip to analyse the dominant harmonics. FFT is also applied to the simulated surface displacement of the housing and the sound pressure at 2000 rpm to analyse their dominant frequency components. The dominant harmonics for the vibration and acoustic noise at 2000 rpm are confirmed. The numerical modelling method presented in this study can also be applied to the other SRMs and electric machines to predict the vibration behaviour and the radiated acoustic noise.","acoustic noise; traction motor drives; finite element analysis; machine control; fast Fourier transforms; stators; electromagnetic forces; automotive engineering; vibrations; reluctance motor drives; reluctance machines; reluctance machine; numerical modelling approach; 24; 16 SRM; numerical simulation; dominant harmonics; simulated surface displacement; numerical modelling method; vibration behaviour; radiated acoustic noise","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-10-01","","","DC systems, Energy conversion & Storage","","",""
"uuid:09455a90-5ad8-4677-965a-6316b91beb4a","http://resolver.tudelft.nl/uuid:09455a90-5ad8-4677-965a-6316b91beb4a","On the nature based flood defence dilemma and its resolution: A game theory based analysis","Janssen, S.K.H. (TU Delft Policy Analysis; Deltares); Vreugdenhil, H.S.I. (TU Delft Policy Analysis; Deltares); Hermans, L.M. (TU Delft Policy Analysis; IHE Delft Institute for Water Education); Slinger, J (TU Delft Policy Analysis; Rhodes University)","","2020","Nature-based flood defence is an innovative design alternative for achieving protection against flooding. Despite significant advancements in science, models and concepts, routine implementation beyond pilot projects remains limited. To better understand why, we have looked into the complexities of nature-based flood defence implementation and its resolutions, modelling decision-making situations using game theory in three nature-based flood defence cases: The Markermeer Dikes, the Afsluitdijk Dam and the Sand Engine. We observe that nature-based flood defence games are of a multi-level and nested nature. While the decision of whether to employ a nature-based flood defence is seemingly made at the project level, this can only happen when it is coherent with the institutional context that is determined at the policy level. A social dilemma is apparent: while a multi-functional nature-based solution is attractive to a coalition of actors, it is not the most beneficial option for individual actors. Hence, they are faced with the dilemma of opting for their maximum benefit or opting for the greater societal benefit which is less favorable to them. This social dilemma can be tackled by making ‘smart moves’, as inspired by the Sand Engine case. The nested nature of the problem requires structural change in the institutional context to enable favourable conditions for nature-based flood defence implementations.","Building with Nature; Implementation; Multi-level decision making; Sand Engine, Afsluitdijk, Markermeerdam; Social dilemma","en","journal article","","","","","","","","","","","Policy Analysis","","",""
"uuid:6ba6ff08-8e31-4b08-84dd-4ff32925a1a5","http://resolver.tudelft.nl/uuid:6ba6ff08-8e31-4b08-84dd-4ff32925a1a5","A single van der pol wake oscillator model for coupled cross-flow and in-line vortex-induced vibrations","Qu, Y. (TU Delft Offshore Engineering; Shanghai Jiao Tong University); Metrikine, A. (TU Delft Offshore Engineering; TU Delft Engineering Structures)","","2020","In this study a new wake oscillator model is proposed to describe the coupled cross-flow and in-line vortex-induced vibrations of an elastically supported rigid cylinder. Different from many other studies where two wake oscillators have been applied, the current model uses only one wake oscillator coupled to both cross-flow and in-line motions. The new model is based on the van der Pol oscillator with the classic acceleration coupling between the wake and cross-flow motion, while the in-line motion is coupled with the wake variable in a nonlinear manner. The predictions of this new model are compared with the existing experimental data and shown to be in good agreement. In addition to the conventional lock-in range that corresponds to reduced velocities between 5 and 8, another lock-in is predicted around reduced velocity of 2.5 due to the in-line vibration. Most importantly, the new model is proved to be able to predict the appearance of the ‘super-upper’ branch at small mass ratios without changing the tuning parameters. The limitations of the model associated with unrealistic predictions of free vibrations with very small mass ratios and those of forced in-line vibrations at high frequencies are also discussed along with a possible remedy.","Coupled cross-flow and in-line vibration; Fluid-structure interaction journal: ocean engineering; Vortex-induced vibration; Wake oscillator model","en","journal article","","","","","","Accepted Author Manuscript","","2021-12-30","","Engineering Structures","Offshore Engineering","","",""
"uuid:10a47179-6f2c-46ed-88d2-a985d772c7b3","http://resolver.tudelft.nl/uuid:10a47179-6f2c-46ed-88d2-a985d772c7b3","Data driven modeling of the reactive oxygen species stimulated by photon energy in light therapies","Dong, Jianfei (Chinese Academy of Sciences); Wang, T. (TU Delft Electronic Components, Technology and Materials; Chinese Academy of Sciences)","","2020","Light therapies can be used to treat fungal infections. A general mechanism is attributed to the generation of cytotoxic reactive oxygen species (ROS) due to light stimulation. The effectiveness of these therapies has been widely studied in the literature via conducting biological experiments, where fungi are exposed to light with various wavelengths and power. However, despite the large amount of work reporting the experimental results, few efforts have been given to build a mathematical model that describes the amount of generated ROS as a function of the photon energy and power of the stimulating light. The lack of such a model still hinders the optimization of the light doses. In this work, we propose a novel modeling method based on experimental data, so as to establish a mathematical relationship between the ROS concentration and the stimulating photon energy and light fluence (energy density). The anti-fungal experiments were performed on Candida {}albicans (C. {}albicans) using four LED light sources with different wavelengths ranging from 385nm to 450nm. Both the viability of the fungi and the ROS concentration therein were measured during the experiments. High fitting accuracy has been achieved by the model, which therefore demonstrates the effectiveness of the proposed modeling techniques.","Biomedical engineering; data driven modeling; light therapy; light-emitting diodes; parameter estimation","en","journal article","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:9ce542e1-b79e-435a-b964-ce87290c5e50","http://resolver.tudelft.nl/uuid:9ce542e1-b79e-435a-b964-ce87290c5e50","Addressing the challenges of climate change risks and adaptation in coastal areas: A review","Toimil, Alexandra (University of Cantabria); Losada, Iñigo J. (University of Cantabria); Nicholls, Robert J. (University of Southampton); Dalrymple, Robert A. (Northwestern University); Stive, M.J.F. (TU Delft Coastal Engineering)","","2020","Climate change is and will continue altering the world's coasts, which are the most densely populated and economically active areas on earth and home for highly valuable ecosystems. While there is considerable relevant research, in the authors' experience this problem remains challenging for coastal engineering. This paper reviews important challenges in this respect and identifies three key actions to address them: (a) refocusing traditional practice towards more climate-aware approaches; (b) developing more comprehensive risk frameworks that include the multi-dimensionality and non-stationarity of their components and consideration of uncertainty; and (c) building bridges between risk assessment and adaptation theory and practice. We conclude that the way forward includes numerous activities including increased observations; the attribution of coastal impacts to their drivers; enhanced climate projections and their integration into impact models; more impact assessments at the local scale; dynamic projections of spatially-distributed exposure and vulnerability; and the exploration of inherently adaptive options. Given the complexity of the possible solutions, more practical guidance is required.","Adaptation; Climate change; Coastal engineering; Non-stationarity; Risk; Uncertainty","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-05-25","","","Coastal Engineering","","",""
"uuid:e6675426-bcc7-4311-b081-4dc7093733ec","http://resolver.tudelft.nl/uuid:e6675426-bcc7-4311-b081-4dc7093733ec","Mapping and quantifying the human-environment interactions in middle Egypt using machine learning and satellite data fusion techniques","Delgado Blasco, José Manuel (TU Delft Mathematical Geodesy and Positioning; Katholieke Universiteit Leuven); Cian, Fabio (Ca' Foscari University Venice; The World Bank); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning); Verstraeten, Gert (Katholieke Universiteit Leuven)","","2020","Population growth in rural areas of Egypt is rapidly transforming the landscape. New cities are appearing in desert areas while existing cities and villages within the Nile floodplain are growing and pushing agricultural areas into the desert. To enable control and planning of the urban transformation, these rapid changes need to be mapped with high precision and frequency. Urban detection in rural areas in optical remote sensing is problematic when urban structures are built using the same materials as their surroundings. To overcome this limitation, we propose a multi-temporal classification approach based on satellite data fusion and artificial neural networks. We applied the proposed methodology to data of the Egyptian regions of El-Minya and part of Asyut governorates collected from 1998 until 2015. The produced multi-temporal land cover maps capture the evolution of the area and improve the urban detection of the European Space Agency (ESA) Climate Change Initiative Sentinel-2 Prototype Land Cover 20 m map of Africa and the Global Human Settlements Layer from the Joint Research Center (JRC). The extension of urban and agricultural areas increased over 65 km2 and 200 km2, respectively, during the entire period, with an accelerated increase analysed during the last period (2010-2015). Finally, we identified the trends in urban population density as well as the relationship between farmed and built-up land.","AI4EO; Egypt; Google earth engine; Land reclamation; Landscape dynamics; Machine learning; Multi-temporal land cover mapping; Satellite data fusion; Urban growth","en","journal article","","","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:9dad0363-d170-47d6-9704-3adfe5e1573a","http://resolver.tudelft.nl/uuid:9dad0363-d170-47d6-9704-3adfe5e1573a","Experimental assessment of the flow resistance of coastal wooden fences","Dào, H.T. (TU Delft Coastal Engineering; Hanoi University); Hofland, Bas (TU Delft Hydraulic Structures and Flood Risk); Stive, M.J.F. (TU Delft Coastal Engineering); Mai, Tri (National University of Civil Engineering)","","2020","Wooden fences are applied as a nature-based solution to support mangrove restoration along mangrove coasts in general and the Mekong Delta coast in particular. The simple structure uses vertical bamboo poles as a frame to store horizontal bamboo and tree branches (brushwood). Fence resistance is quantitatively determined by the drag coefficient exerted by the fence material on the flow; however, the behaviour of drag is predictable only when the arrangement of the cylinders is homogeneous. Therefore, for more arbitrary arrangements, the Darcy-Forchheimer equations need to be considered. In this study, the law of fluid flow was applied by forcing a constant flow of water through the fence material and measuring the loss of hydraulic pressure over a fence thickness. Fences, mainly using bamboo sticks, were installed with model-scale and full-scale diameters applying two main arrangements, inhomogeneous and staggered. Our empirical findings led to several conclusions. The bulk drag coefficient (CD) is influenced by the flow regime represented by Reynolds number. The drag coefficient decreases with the increase of the porosity, which strongly depends on fence arrangements. Finally, the Forchheimer coefficients can be linked to the drag coefficient through a related porosity parameter at high turbulent conditions. The staggered arrangement is well-predicted by the Ergun-relations for the Darcy-Forchheimer coefficients when an inhomogeneous arrangement with equal porosity and diameter leads to a large drag and flow resistance.","Coastal engineering; Hydraulic gradient; Mekong Delta; Nature-based solutions; Physical experiments; Porous structures","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:1031e57f-0d9c-4d49-b766-e3a6b05045b4","http://resolver.tudelft.nl/uuid:1031e57f-0d9c-4d49-b766-e3a6b05045b4","Sub-nanoscale Surface Engineering of TiO2Nanoparticles by Molecular Layer Deposition of Poly(ethylene terephthalate) for Suppressing Photoactivity and Enhancing Dispersibility","La Zara, D. (TU Delft ChemE/Product and Process Engineering); Bailey, Maximilian R. (ETH Zürich; Student TU Delft); Hagedoorn, P.L. (TU Delft BT/Biocatalysis); Benz, D. (TU Delft ChemE/Product and Process Engineering); Quayle, Michael J. (AstraZeneca); Folestad, Staffan (AstraZeneca); van Ommen, J.R. (TU Delft ChemE/Product and Process Engineering)","","2020","In this work, we report molecular layer deposition (MLD) of ultrathin poly(ethylene terephthalate) (PET) films on gram-scale batches of ultrafine particles for the first time. TiO2 P25 nanoparticles (NPs) are coated up to 50 cycles in an atmospheric-pressure fluidized-bed reactor at 150 °C using terephthaloyl chloride and ethylene glycol as precursors. Ex-situ diffuse reflectance infrared Fourier transform spectroscopy, thermogravimetric analysis, and transmission electron microscopy show the linear growth at 0.05 nm/cycle of uniform and conformal PET films, which are unattainable with conventional wet-phase approaches. The sub-nanoscale and nanoscale PET films not only suppress the photocatalytic activity of TiO2 NPs by hindering the access of water and reactant molecules to the TiO2 surface but also improve the dispersibility of TiO2 NPs in both organic and aqueous media. Still, the bulk optical properties, electronic structure, and surface area of TiO2 are essentially unaffected by the MLD process. This study demonstrates the industrial relevance of MLD to simultaneously suppress the photoactivity and enhance the dispersibility of commercial TiO2 P25 nanopowders, which is crucial for their use for example as UV-screening agents in sunscreens and as white pigments in paints. Moreover, by rapidly modifying the surface properties of particles in a controlled manner at the sub-nanometer scale, particle MLD can serve many other applications ranging from nanofluids to emulsions to polymer nanocomposites.","improved dispersion; inorganic-organic nanocomposite; molecular layer deposition; organic coating; polyethylene terephthalate; sub-nanoscale; suppressed photoactivity; surface engineering; TiO","en","journal article","","","","","","","","","","","ChemE/Product and Process Engineering","","",""
"uuid:6f3413d4-f813-4680-8e0e-1c21451caf26","http://resolver.tudelft.nl/uuid:6f3413d4-f813-4680-8e0e-1c21451caf26","Applying Non-canonical Redox Cofactors in Fermentation Processes","Weusthuis, Ruud A. (Wageningen University & Research); Folch, Pauline L. (Wageningen University & Research); Pozo-Rodríguez, Ana (Wageningen University & Research); Paul, C.E. (TU Delft BT/Biocatalysis)","","2020","Fermentation processes are used to sustainably produce chemicals and as such contribute to the transition to a circular economy. The maximum theoretical yield of a conversion can only be approached if all electrons present in the substrate end up in the product. Control over the electrons is therefore crucial. However, electron transfer via redox cofactors results in a diffuse distribution of electrons over metabolism. To overcome this challenge, we propose to apply non-canonical redox cofactors (NRCs) in metabolic networks: cofactors that channel electrons exclusively from substrate to product, forming orthogonal circuits for electron transfer.","Biotechnology; Metabolic Engineering; Microbiology","en","review","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:e6ca80f4-9c53-4ebd-97d6-11162221a0fc","http://resolver.tudelft.nl/uuid:e6ca80f4-9c53-4ebd-97d6-11162221a0fc","Direct Water Injection in Catholyte-Free Zero-Gap Carbon Dioxide Electrolyzers","De Mot, Bert (Universiteit Antwerpen); Ramdin, M. (TU Delft Engineering Thermodynamics); Hereijgers, Jonas (Universiteit Antwerpen); Vlugt, T.J.H. (TU Delft Engineering Thermodynamics); Breugelmans, Tom (Universiteit Antwerpen; Flemish Institute for Technological Research)","","2020","A zero-gap flow electrolyzer with a tin-coated gas diffusion electrode as the cathode was used to convert humidified gaseous CO2 to formate. The influence of humidification, flow pattern and the type of membrane on the faradaic efficiency (FE), product concentration, and salt precipitation were investigated. We demonstrated that water management in the gas diffusion electrode was crucial to avoid flooding and (bi)carbonate precipitation, to uphold a high FE and formate concentration. Direct water injection was validated as a novel approach for water management. At 100 mA/cm2, direct water injection in combination with an interdigitated flow channel resulted in a FE of 80 % and a formate concentration of 65.4+/−0.3 g/l without salt precipitation for a prolonged CO2 electrolysis of 1 h. The use of bipolar membranes in the zero-gap configuration mainly produced hydrogen. These results are important for the design of commercial scale CO2 electrolyzers.","Electrochemical Engineering, CO Reduction; Electrochemistry; Environmental Chemistry; Formate; Reactor Engineering","en","journal article","","","","","","Accepted Author Manuscript","","2021-09-07","","","Engineering Thermodynamics","","",""
"uuid:41ab79c7-ead4-416a-8931-3f86bf638a00","http://resolver.tudelft.nl/uuid:41ab79c7-ead4-416a-8931-3f86bf638a00","Using scaffolding to formalize digital coach support for low-literate learners","Schouten, D.G.M. (TU Delft Interactive Intelligence); Massink, Pim (Universiteit Utrecht); Donker, Stella F. (Universiteit Utrecht); Neerincx, M.A. (TU Delft Interactive Intelligence)","","2020","In this study, we attempt to specify the cognitive support behavior of a previously designed embodied conversational agent coach that provides learning support to low-literates. Three knowledge gaps are identified in the existing work: an incomplete specification of the behaviors that make up ‘support,’ an incomplete specification of how this support can be personalized, and unclear speech recognition rules. We use the socio-cognitive engineering method to update our foundation of knowledge with new online banking exercises, low-level scaffolding and user modeling theory, and speech recognition. We then refine the design of our coach agent by creating comprehensive cognitive support rules that adapt support based on learner needs (the ‘Generalized’ approach) and attune the coach’s support delay to user performance in previous exercises (the ‘Individualized’ approach). A prototype is evaluated in a 3-week within- and between-subjects experiment. Results show that the specified cognitive support is effective: Learners complete all exercises, interact meaningfully with the coach, and improve their online banking self-efficacy. Counter to hypotheses, the Individualized approach does not improve on the Generalized approach. Whether this indicates suboptimal operationalization or a deeper problem with the Individualized approach remains as future work.","Design research; Embodied conversational agent; Requirements engineering; Scaffolding; User modeling; Virtual learning environment","en","journal article","","","","","","","","","","","Interactive Intelligence","","",""
"uuid:636090e4-e7db-406a-bfae-979d8d23c449","http://resolver.tudelft.nl/uuid:636090e4-e7db-406a-bfae-979d8d23c449","Predicting by-product gradients of baker’s yeast production at industrial scale: A practical simulation approach","Hajian, Christopher Sarkizi Shams (University of Stuttgart); Haringa, C. (DSM); Noorman, H.J. (TU Delft BT/Bioprocess Engineering; DSM); Takors, Ralf (University of Stuttgart)","","2020","Scaling up bioprocesses is one of the most crucial steps in the commercialization of bioproducts. While it is known that concentration and shear rate gradients occur at larger scales, it is often too risky, if feasible at all, to conduct validation experiments at such scales. Using computational fluid dynamics equipped with mechanistic biochemical engineering knowledge of the process, it is possible to simulate such gradients. In this work, concentration profiles for the by-products of baker’s yeast production are investigated. By applying a mechanistic black-box model, concentration heterogeneities for oxygen, glucose, ethanol, and carbon dioxide are evaluated. The results suggest that, although at low concentrations, ethanol is consumed in more than 90% of the tank volume, which prevents cell starvation, even when glucose is virtually depleted. Moreover, long exposure to high dissolved carbon dioxide levels is predicted. Two biomass concentrations, i.e., 10 and 25 g/L, are considered where, in the former, ethanol production is solely because of overflow metabolism while, in the latter, 10% of the ethanol formation is due to dissolved oxygen limitation. This method facilitates the prediction of the living conditions of the microorganism and its utilization to address the limitations via change of strain or bioreactor design or operation conditions. The outcome can also be of value to design a representative scale-down reactor to facilitate strain studies.","Bioprocess engineering; Bioreactor; Computational fluid dynamics; Concentration gradients; Digital twin; Mechanistic kinetic model; Saccharomyces cerevisiae; Scale-down; Scale-up","en","journal article","","","","","","","","","","","BT/Bioprocess Engineering","","",""
"uuid:2506bbc7-ef18-4ac4-82f2-4311b5f3fcf5","http://resolver.tudelft.nl/uuid:2506bbc7-ef18-4ac4-82f2-4311b5f3fcf5","PISA design model for monopiles for offshore wind turbines: Application to a stiff glacial clay till","Byrne, Byron W. (University of Oxford); Houlsby, Guy T. (University of Oxford); Burd, Harvey J. (University of Oxford); Gavin, Kenneth (TU Delft Geo-engineering); Igoe, David J.P. (Trinity College Dublin); Jardine, Richard J. (Imperial College London); Martin, Christopher M. (University of Oxford); McAdam, Ross A. (University of Oxford); Potts, David M. (Imperial College London)","","2020","Offshore wind turbines in shallow coastal waters are typically supported on monopile foundations. Although three-dimensional (3D) finite-element methods are available for the design of monopiles in this context, much of the routine design work is currently conducted using simplified one-dimensional (1D) models based on the p-y method. The p-y method was originally developed for the relatively large embedded length-to-diameter ratio (L/D) piles that are typically employed in offshore oil and gas structures. Concerns exist, however, that this analysis approach may not be appropriate for monopiles with the relatively low values of L/D that are typically adopted for offshore wind turbine structures. This paper describes a new 1D design model for monopile foundations; the model is specifically formulated for offshore wind turbine applications, although the general approach could be adopted for other applications. The model draws on the conventional p-y approach, but extends it to include additional components of soil reaction that act on the pile. The 1D model is calibrated using a set of bespoke 3D finite-element analyses of monopile performance, for pile characteristics and loading conditions that span a predefined design space. The calibrated 1D model provides results that match those obtained from the 3D finite-element calibration analysis, but at a fraction of the computational cost. Moreover, within the calibration space, the 1D model is capable of delivering high-fidelity computations of monopile performance that can be used directly for design purposes. This 1D modelling approach is demonstrated for monopiles installed in a stiff, overconsolidated glacial clay till with a typical North Sea strength and stiffness profile. Although the current form of the model has been developed for homogeneous soil and monotonic loading, it forms a basis from which extensions for soil layering and cyclic loading can be developed. The general approach can be applied to other foundation and soil-structure interaction problems, in which bespoke calibration of a simplified model can lead to more efficient design.","design; limit state design/analysis; numerical modelling; offshore engineering; piles & piling; soil/structure interaction","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:8d558fc7-62b4-49e3-a1e4-87a4c77b42d2","http://resolver.tudelft.nl/uuid:8d558fc7-62b4-49e3-a1e4-87a4c77b42d2","Finite-element modelling of laterally loaded piles in a stiff glacial clay till at Cowden","Zdravkovic, Lidija (Imperial College London); Taborda, David M.G. (Imperial College London); Potts, David M. (Imperial College London); Abadias, David (Arup); Burd, Harvey J. (University of Oxford); Byrne, Byron W. (University of Oxford); Gavin, Kenneth (TU Delft Geo-engineering); Houlsby, Guy T. (University of Oxford); Jardine, Richard J. (University of Oxford)","","2020","The PISA project was a combined field testing/numerical modelling study with the aim of developing improved design procedures for large-diameter piles subjected to lateral loading. This paper describes the development of a three-dimensional finite-element model for the medium-scale pile tests that were conducted in Cowden till as part of the PISA work. The paper places particular emphasis on the consistent interpretation of the soil data determined from the available field and laboratory information. An enhanced version of the modified Cam clay model was employed in the numerical analyses, featuring a non-linear Hvorslev surface, a generalised shape for the yield and plastic potential surfaces in the deviatoric plane and a non-linear formulation for the elastic shear modulus. Three-dimensional finite-element analyses were performed prior to the field tests. Excellent agreement between the measured and simulated behaviour for a range of pile geometries was observed, demonstrating the accuracy of the numerical model and the adequacy of the calibration process for the constitutive model. The developed numerical model confirmed the premise of the PISA design method that site-specific ground characterisation and advanced numerical modelling can directly facilitate the development of additional soil reaction curves for use in new design models for laterally loaded piles in a stiff clay till.","full-scale tests; model tests; offshore engineering; piles AND piling; soil/structure interaction","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:aa901a18-b2fd-4d0d-b46e-695c0996df13","http://resolver.tudelft.nl/uuid:aa901a18-b2fd-4d0d-b46e-695c0996df13","Monotonic laterally loaded pile testing in a dense marine sand at Dunkirk","McAdam, Ross A. (University of Oxford); Byrne, Byron W. (University of Oxford); Houlsby, Guy T. (Trinity College Dublin); Beuckelaers, William J.A.P. (University of Oxford); Burd, Harvey J. (University of Oxford); Gavin, Kenneth (TU Delft Geo-engineering); Igoe, David J.P. (Trinity College Dublin); Jardine, Richard J. (Imperial College London); Martin, Christopher M. (University of Oxford)","","2020","The results obtained from a field testing campaign on laterally loaded monopiles, conducted at a dense sand site in Dunkirk, northern France are described. These tests formed part of the PISA project on the development of improved design methods for monopile foundations for offshore wind turbines. Results obtained from monotonic loading tests on piles of three different diameters (0·273 m, 0·762 m and 2·0 m) are presented. The piles had length-to-diameter ratios (L/D) of between 3 and 10. The tests consisted principally of the application of monotonic loads, incorporating periods of held constant load to investigate creep effects. The influence of loading rate was also investigated. Data are presented on the overall load-displacement behaviour of each of the test piles. Measured data on bending moments and inclinations induced in the piles are also provided. Inferences are made for the displacements in the embedded length of the piles. These field data will support the development of a new one-dimensional modelling approach for the design of monopile foundations for offshore wind turbines. They also form a unique database of field measurements in a dense sand, from lateral loading of piles at a vertical distance above the ground surface.","full-scale tests; model tests; offshore engineering; piles AND piling; soil/structure interaction","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:f729422c-22ee-4554-a6da-8e125de09338","http://resolver.tudelft.nl/uuid:f729422c-22ee-4554-a6da-8e125de09338","PISA design model for monopiles for offshore wind turbines: Application to a marine sand","Burd, Harvey J. (University of Oxford); Taborda, David M.G. (Imperial College London); Zdravkovic, Lidija (Imperial College London); Abadie, Christelle N. (University of Cambridge); Byrne, Byron W. (University of Oxford); Houlsby, Guy T. (University of Oxford); Gavin, Kenneth (TU Delft Geo-engineering); Igoe, David J.P. (Trinity College Dublin); Jardine, Richard J. (Imperial College London)","","2020","This paper describes a one-dimensional (1D) computational model for the analysis and design of laterally loaded monopile foundations for offshore wind turbine applications. The model represents the monopile as an embedded beam and specially formulated functions, referred to as soil reaction curves, are employed to represent the various components of soil reaction that are assumed to act on the pile. This design model was an outcome of a recently completed joint industry research project - known as PISA - on the development of new procedures for the design of monopile foundations for offshore wind applications. The overall framework of the model, and an application to a stiff glacial clay till soil, is described in a companion paper by Byrne and co-workers; the current paper describes an alternative formulation that has been developed for soil reaction curves that are applicable to monopiles installed at offshore homogeneous sand sites, for drained loading. The 1D model is calibrated using data from a set of three-dimensional finite-element analyses, conducted over a calibration space comprising pile geometries, loading configurations and soil relative densities that span typical design values. The performance of the model is demonstrated by the analysis of example design cases. The current form of the model is applicable to homogeneous soil and monotonic loading, although extensions to soil layering and cyclic loading are possible.","design; limit state design/analysis; numerical modelling; offshore engineering; piles AND piling; soil/structure interaction","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:76fa65e3-2ae3-4b49-9d4c-11c725fc99e0","http://resolver.tudelft.nl/uuid:76fa65e3-2ae3-4b49-9d4c-11c725fc99e0","Innovative Tissue-Engineered Strategies for Osteochondral Defect Repair and Regeneration: Current Progress and Challenges","Zhou, Liangbin (Chinese University of Hong Kong); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Malda, Jos (Universiteit Utrecht); Stoddart, Martin J. (AO Research Institute Davos, Davos); Lai, Yuxiao (Chinese Academy of Sciences); Richards, R. Geoff (AO Research Institute Davos, Davos); Ki-wai Ho, Kevin (Chinese University of Hong Kong); Qin, Ling (Chinese University of Hong Kong; Chinese Academy of Sciences)","","2020","Clinical treatments for the repair of osteochondral defects (OCD) are merely palliative, not completely curative, and thus enormously unfulfilled challenges. With the in-depth studies of biology, medicine, materials, and engineering technology, the conception of OCD repair and regeneration should be renewed. During the past decades, many innovative tissue-engineered approaches for repairing and regenerating damaged osteochondral units have been widely explored. Various scaffold-free and scaffold-based strategies, such as monophasic, biphasic, and currently fabricated multiphasic and gradient architectures have been proposed and evaluated. Meanwhile, progenitor cells and tissue-specific cells have also been intensively investigated in vivo as well as ex vivo. Concerning bioactive factors and drugs, they have been combined with scaffolds and/or living cells, and even released in a spatiotemporally controlled manner. Although tremendous progress has been achieved, further research and development (R&D) is needed to convert preclinical outcomes into clinical applications. Here, the osteochondral unit structure, its defect classifications, and diagnosis are summarized. Commonly used clinical reparative techniques, tissue-engineered strategies, emerging 3D-bioprinting technologies, and the status of their clinical applications are discussed. Existing challenges to translation are also discussed and potential solutions for future R&D directions are proposed.","clinical applications; osteochondral defect repair and regeneration; scaffolds; tissue-engineered strategies","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-04-26","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:89644699-74d2-4bfc-a87c-1f1efe97aaf5","http://resolver.tudelft.nl/uuid:89644699-74d2-4bfc-a87c-1f1efe97aaf5","Monotonic laterally loaded pile testing in a stiff glacial clay till at Cowden","Byrne, Byron W. (University of Oxford); McAdam, Ross A. (University of Oxford); Burd, Harvey J. (University of Oxford); Beuckelaers, William J.A.P. (University of Oxford); Gavin, Kenneth (TU Delft Geo-engineering); Houlsby, Guy T. (University of Oxford); Igoe, David J.P. (Trinity College Dublin); Jardine, Richard J. (Imperial College London); Martin, Christopher M. (University of Oxford)","","2020","This paper describes the results obtained from a field testing campaign on laterally loaded monopiles conducted at Cowden, UK, where the soil consists principally of a heavily overconsolidated glacial till. These tests formed part of the PISA project on the development of improved design methods for monopile foundations for offshore wind turbines. Results obtained for monotonic loading tests on piles of three different diameters (0·273 m, 0·762 m and 2·0 m) are presented. The piles had length-to-diameter ratios (L/D) of between 3 and 10. The tests included the application of monotonic loading incorporating periods of constant load to investigate creep effects, and investigations on the influence of loading rate. Data are presented on measured bending moments and inclinations induced in the piles. Inferred data on lateral displacements of the embedded section of the piles are determined using an optimised structural model. These field data support the development of a new one-dimensional modelling approach for the design of monopile foundations for offshore wind turbines. They also form a unique database of field measurements in an overconsolidated clay, from lateral loading of piles at a vertical distance above the ground surface.","full-scale tests; model tests; offshore engineering; piles AND piling; soil/structure interaction","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:205cb887-23c7-4cf4-82d9-2618ff335b86","http://resolver.tudelft.nl/uuid:205cb887-23c7-4cf4-82d9-2618ff335b86","Process intensification education contributes to sustainable development goals. Part 2","Fernandez Rivas, David (University of Twente); Boffito, Daria C. (Polytechnique Montreal); Faria-Albanese, Jimmy (University of Twente); Glassey, Jarka (Newcastle University); Afraz, Nona (Otto-von-Guericke University); Akse, Henk (Process Intensification Network); Boodhoo, Kamelia V.K. (Newcastle University); Bos, Rene (Universiteit Gent); Cantin, Judith (Polytechnique Montreal); (Emily) Chiang, Yi Wai (University of Guelph); Commenge, Jean Marc (Lorraine University); Dubois, Jean Luc (Corporate R&D); Galli, Federico (Polytechnique Montreal); de Mussy, Jean Paul Gueneau (Katholieke Universiteit Leuven); Harmsen, Jan (Harmsen Consultancy BV); Kalra, Siddharth (Student TU Delft); Keil, Frerich J. (Hamburg University of Technology); Morales-Menendez, Ruben (Tecnologico de Monterrey); Navarro-Brull, Francisco J. (Universitat d'Alacant); Noël, Timothy (Eindhoven University of Technology); Ogden, Kim (University of Arizona); Patience, Gregory S. (Polytechnique Montreal); Reay, David (Newcastle University); Santos, Rafael M. (University of Guelph); Smith-Schoettker, Ashley (RAPID Manufacturing Institute); Stankiewicz, A.I. (TU Delft Intensified Reaction and Separation Systems); van den Berg, Henk (University of Twente); van Gerven, Tom (Katholieke Universiteit Leuven); van Gestel, Jeroen (Universiteit Utrecht); van der Stelt, Michiel (Universiteit Utrecht); van de Ven, Mark (Rijksinstituut voor Volksgezondheid en Milieu (RIVM)); Weber, R. S. (Pacific Northwest National Laboratory)","","2020","Achieving the United Nations sustainable development goals requires industry and society to develop tools and processes that work at all scales, enabling goods delivery, services, and technology to large conglomerates and remote regions. Process Intensification (PI) is a technological advance that promises to deliver means to reach these goals, but higher education has yet to totally embrace the program. Here, we present practical examples on how to better teach the principles of PI in the context of the Bloom’s taxonomy and summarise the current industrial use and the future demands for PI, as a continuation of the topics discussed in Part 1. In the appendices, we provide details on the existing PI courses around the world, as well as teaching activities that are showcased during these courses to aid students’ lifelong learning. The increasing number of successful commercial cases of PI highlight the importance of PI education for both students in academia and industrial staff.","Chemical engineering; Education challenge; Entrepreneurship; Industry challenge; Pedagogy; Process design; Process intensification; Sustainability","en","journal article","","","","","","","","","","","Intensified Reaction and Separation Systems","","",""
"uuid:47ebf984-0d3a-4892-b6c9-6fc9b335a6ab","http://resolver.tudelft.nl/uuid:47ebf984-0d3a-4892-b6c9-6fc9b335a6ab","The open design education approach: An integrative teaching and learning concept for management and engineering","Binnekamp, R. (TU Delft Real Estate Management); Wolfert, A.R.M. (TU Delft Integral Design & Management); Kammouh, O. (TU Delft Integral Design & Management); Nogal Macho, M. (TU Delft Integral Design & Management)","Cardoso, Alberto (editor); Alves, Gustavo R. (editor); Restivo, Teresa (editor)","2020","Construction Management and Engineering students need to acquire managing skills for solving real-world problems that are complex, rarely straightforward and lack 'one right answer'. For this, they need to become 'open designers', capable to be reflective, integrative and creative in- and on action with dynamic and new situations. In this paper, the so-called Open Design Learning Circle (ODLC) will be proposed as an innovative educational concept in which engineering-, management- and pedagogic sciences are integrated. Within this concept the students 'dialogue' with: 1) an objective open glass box model covering engineering products and management processes (outer) and, 2) their subjective open human threefold, reflecting their personal learning (inner). The integration of both human and model dialogues is essential for the emergence of new knowledge and creative insights for open designs, which is essentially distinct from more traditional learning concepts. To enable this emergence, a self-chosen system of interest is the 'experiential vehicle' that forms the basis for a self-created textbook and model. Thereby, the ODLC forms the fundamental basis for creating 'open and persistent learners'. In this paper, it also will be shown how the ODLC can be operationalized into a learning cycle and how it has been implemented in an example course on systems engineering management within the MSc Construction Management Engineering curriculum at the TU Delft. Finally, some preliminary student findings and next steps for further research are discussed.","Co-creating and co-sensing; Co-reflecting; Construction Management and Engineering; Experiential Learning; Integrative Education; Management Process/Engineering Product/Learning Person; Open Design Learning Circle/ Cycle; Problem Solving; System of Interest","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-12-25","","","Real Estate Management","","",""
"uuid:af5a053c-7be2-4e53-8e22-014f3cdbcc2e","http://resolver.tudelft.nl/uuid:af5a053c-7be2-4e53-8e22-014f3cdbcc2e","Mechanical behavior of printed strain hardening cementitious composites","Chaves Figueiredo, S. (TU Delft Materials and Environment); Romero Rodriguez, C. (TU Delft Materials and Environment); Ahmed, Zeeshan Y. (Eindhoven University of Technology); Bos, Derk H. (Eindhoven University of Technology); Xu, Y. (TU Delft Materials and Environment); Salet, Theo M. (Eindhoven University of Technology); Copuroglu, Oguzhan (TU Delft Materials and Environment); Schlangen, E. (TU Delft Materials and Environment); Bos, Freek P. (Eindhoven University of Technology)","","2020","Extrusion based additive manufacturing of cementitious materials has demonstrated strong potential to become widely used in the construction industry. However, the use of this technique in practice is conditioned by a feasible solution to implement reinforcement in such automated process. One of the most successful ductile materials in civil engineering, strain hardening cementitious composites (SHCC) have a high potential to be employed for three-dimensional printing. The match between the tailored brittle matrix and ductility of the fibres enables these composites to develop multiple cracks when loaded under tension. Using previously developed mixtures, this study investigates the physical and mechanical performance of printed SHCC. The anisotropic behavior of the materials is explored by means of mechanical tests in several directions and micro computed tomography tests. The results demonstrated a composite showing strain hardening behavior in two directions explained by the fibre orientation found in the printed elements. Moreover, the printing technique used also has guaranteed an enhanced bond in between the printed layers.","3D printing; Engineered cementitious composites (ECC); Fibre reinforcement; Strain hardening cementitious composites (SHCC)","en","journal article","","","","","","","","","","","Materials and Environment","","",""
"uuid:d02d715c-50fe-4cce-b0ed-539216a6557e","http://resolver.tudelft.nl/uuid:d02d715c-50fe-4cce-b0ed-539216a6557e","Interdisciplinary engineering education: A review of vision, teaching, and support","Van den Beemt, Antoine (Eindhoven University of Technology); MacLeod, Miles (University of Twente); Van der Veen, Jan (University of Twente); Van de Ven, Anne (Eindhoven University of Technology); van Baalen, Sophie (University of Twente); Klaassen, R.G. (TU Delft Teaching & Learning Services); Boon, Mieke (University of Twente)","","2020","Background: Societal challenges that call for a new type of engineer suggest the need for the implementation of interdisciplinary engineering education (IEE). The aim of IEE is to train engineering students to bring together expertise from different disciplines in a single context. This review synthesizes IEE research with a focus on characterizing vision, teaching practices, and support. Purpose: We aim to show how IEE is conceptualized, implemented, and facilitated in higher engineering education at the levels of curricula and courses. This aim leads to two research questions:. What aspects of vision, teaching, and support have emerged as topics of interest in empirical studies of IEE?. What points of attention regarding vision, teaching, and support can be identified in empirical studies of IEE as supporting or challenging IEE?. Scope/Method: Ninety-nine studies published between 2005 and 2016 were included in a qualitative analysis across studies. The procedure included formulation of research questions, searching and screening of studies according to inclusion/exclusion criteria, description of study characteristics, appraisal, and synthesis of results. Conclusions: Challenges exist for identifying clear learning goals and assessments for interdisciplinary education in engineering (vision). Most pedagogy for interdisciplinary learning is designed to promote collaborative teamwork requiring organization and team management. Our review suggests that developing interdisciplinary skills, knowledge, and values needs sound pedagogy and teaming experiences that provide students with authentic ways of engaging in interdisciplinary practice (teaching). Furthermore, there is a limited understanding of what resources hinder the development of engineering programs designed to support interdisciplinarity (support).","engineering curriculum; higher education; interdisciplinary; teaching and learning","en","review","","","","","","","","","","","Teaching & Learning Services","","",""
"uuid:76478b8c-a5e2-465b-8a83-48b49fa3853c","http://resolver.tudelft.nl/uuid:76478b8c-a5e2-465b-8a83-48b49fa3853c","Reply to Lanari, R., et al. comment on “pre-collapse space geodetic observations of critical infrastructure: The morandi bridge, Genoa, Italy” by Milillo et al. (2019)","Milillo, Pietro (University of California; Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Giardina, Giorgia (TU Delft Geo-engineering); Perissin, Daniele (Raser Limited); Milillo, Giovanni (Italian Space Agency); Coletta, Alessandro (Raser Limited); Terranova, Carlo (Geoportale Nazionale)","","2020","We would like to thank our colleagues for their comment, as we believe that this discussion further highlights the importance of innovative research in the emerging field of InSAR applications to civil engineering structures. We discuss the statement from Lanari et al. (2020): “Our analysis shows that, although both the SBAS and the TomoSAR analyses allow achieving denser coherent pixel maps relevant to the Morandi bridge, nothing of the pre-collapse large displacements reported in Milillo et al. (2019) appears in our results”. In this reply we argue that (1) they cannot detect the pre-collapse movements because they use standard approaches and (2) the signals of interest become observable by changing the point of view.","Bridge engineering; Critical infrastructure monitoring; Synthetic aperture radar interferometry (InSAR)","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:18df757e-e803-4f6c-8b91-acec76a7bf4f","http://resolver.tudelft.nl/uuid:18df757e-e803-4f6c-8b91-acec76a7bf4f","Flood damage cost estimation in 3D based on an indicator modelling framework","Elfouly, Mostafa (Technische Universität München); Labetski, A. (TU Delft Urban Data Science)","","2020","Flooding and other natural disasters pose risks to cities and residential homes, and these are set to increase in the face of climate change. Single-family residential buildings are of particular interest because they are difficult to insure and often highlight wealth discrepancies in society in the wake of natural disasters. Calculating building replacement cost based on a specific natural disaster is of interest to municipalities and city planners who are working to prepare their cities for potential future costs of recovery. There are models designed by flood modellers, and there are models designed by city planners. This paper presents a novel Indicator Modelling Framework (IMF) by bringing together a model from the flooding domain (HAZUS) and a model from the geospatial application domain (e.g. CityGML) and weaving them together. The weaving process automatically calculates the building replacement cost for buildings based on a flood scenario as well as generates domain-specific metadata. The weaving process capitalizes on the strengths of both models, and future work will focus on weaving between models in other domains.","CityGML; General Indicator Model; Indicator Modelling Framework; flood modelling; metadata; model-driven engineering","en","journal article","","","","","","","","","","","Urban Data Science","","",""
"uuid:05286e97-a862-4ba1-a54f-31b1175d1c8f","http://resolver.tudelft.nl/uuid:05286e97-a862-4ba1-a54f-31b1175d1c8f","3D printing on-water sports boards with bio-inspired core designs","Soltani, Aref (Nottingham Trent University; Isfahan University of Technology); Noroozi, Reza (Nottingham Trent University; University of Tehran); Bodaghi, Mahdi (Nottingham Trent University); Zolfagharian, Ali (Deakin University); Hedayati, R. (TU Delft Novel Aerospace Materials)","","2020","Modeling and analyzing the sports equipment for injury prevention, reduction in cost, and performance enhancement have gained considerable attention in the sports engineering community. In this regard, the structure study of on-water sports board (surfboard, kiteboard, and skimboard) is vital due to its close relation with environmental and human health as well as performance and safety of the board. The aim of this paper is to advance the on-water sports board through various bio-inspired core structure designs such as honeycomb, spiderweb, pinecone, and carbon atom configuration fabricated by three-dimensional (3D) printing technology. Fused deposition modeling was employed to fabricate complex structures from polylactic acid (PLA) materials. A 3D-printed sample board with a uniform honeycomb structure was designed, 3D printed, and tested under three-point bending conditions. A geometrically linear analytical method was developed for the honeycomb core structure using the energy method and considering the equivalent section for honeycombs. A geometrically non-linear finite element method based on the ABAQUS software was also employed to simulate the boards with various core designs. Experiments were conducted to verify the analytical and numerical results. After validation, various patterns were simulated, and it was found that bio-inspired functionally graded honeycomb structure had the best bending performance. Due to the absence of similar designs and results in the literature, this paper is expected to advance the state of the art of on-water sports boards and provide designers with structures that could enhance the performance of sports equipment.","3D printing; Bio-inspired design; FEM; Kiteboard; Sports engineering; Surfboard","en","journal article","","","","","","","","","","","Novel Aerospace Materials","","",""
"uuid:93b461c6-4ce1-4f05-9394-59741bb11b0c","http://resolver.tudelft.nl/uuid:93b461c6-4ce1-4f05-9394-59741bb11b0c","A Pioneering Career in Catalysis: Manfred T. Reetz","Acevedo-Rocha, Carlos G. (Biosyntia ApS, Copenhagen); Hollmann, F. (TU Delft BT/Biocatalysis); Sanchis, Joaquin (Monash University); Sun, Zhoutong (Chinese Academy of Sciences)","","2020","In this invited Account, we highlight the enormous scientific breadth of our mentor Professor Manfred T. Reetz. It stretches from the development of organometallic reagents and transition metal catalysts to the adventurous idea of directed evolution of chemo-, stereo-, and regioselective enzymes, which he considered to be most important. We hope to show that Reetz did not consider these research areas to be totally unrelated realms, and attempt to reveal his transdisciplinary way of thinking about methodology development. Since biocatalysis has become crucial for chemical synthesis, we mainly focus on Reetz's contributions in this area. Some personal reflections from some of his former co-workers are also included, which reveal the stimulating atmosphere in the Reetz group in terms of science, career advice, and the importance of ethical considerations.","biocatalysis; directed evolution; protein engineering; regioselectivity; saturation mutagenesis; stereoselectivity","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:1281ce36-7afc-43d9-ad83-b69c60fbd49a","http://resolver.tudelft.nl/uuid:1281ce36-7afc-43d9-ad83-b69c60fbd49a","Search-Based Crash Reproduction and Its Impact on Debugging","Soltani, M. (TU Delft Software Engineering); Panichella, A. (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology)","","2020","Software systems fail. These failures are often reported to issue tracking systems, where they are prioritized and assigned to responsible developers to be investigated. When developers debug software, they need to reproduce the reported failure in order to verify whether their fix actually prevents the failure from happening again. Since manually reproducing each failure could be a complex task, several automated techniques have been proposed to tackle this problem. Despite showing advancements in this area, the proposed techniques showed various types of limitations. In this paper, we present EvoCrash, a new approach to automated crash reproduction based on a novel evolutionary algorithm, called Guided Genetic Algorithm (GGA). We report on our empirical study on using EvoCrash to reproduce 54 real-world crashes, as well as the results of a controlled experiment, involving human participants, to assess the impact of EvoCrash tests in debugging. Based on our results, EvoCrash outperforms state-of-the-art techniques in crash reproduction and uncovers failures that are undetected by classical coverage-based unit test generation tools. In addition, we observed that using EvoCrash helps developers provide fixes more often and take less time when debugging, compared to developers debugging and fixing code without using EvoCrash tests.","Search-Based Software Testing; Genetic Algorithms; Automated Crash Reproduction; Empirical Software Engineering; empirical software engineering; Search-based software testing; genetic algorithms; automated crash reproduction","en","journal article","","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:a66b84b9-6c66-4c9c-a2e1-87163244ae07","http://resolver.tudelft.nl/uuid:a66b84b9-6c66-4c9c-a2e1-87163244ae07","The effect of hydrodynamics on the interaction between floating structures and flexible ice floes: A study based on potential theory","Keijdener, C. (TU Delft Offshore Engineering)","Hendrikse, H. (promotor); Metrikine, A. (promotor); Delft University of Technology (degree granting institution)","2019","The Arctic presents a great opportunity for two major industries. First, since the region is expected to contain a significant amount of hydrocarbon reserves, it is very attractive for the oil and gas industry. Second, the receding extent of sea ice is making the region more accessible for shipping and, therefore, an opportunity is emerging for the shipping industry. In order to exploit both economic opportunities in a safe and sustainable manner, a thorough understanding of the interaction between ice and floating structures is needed. The most common method for studying ice-floater interaction (IFI) is via numerical modeling, which the fluid is a major component of. As fluid-ice interaction is challenging to model, a wide range of simplified and sophisticated models are employed to meet the challenge. A literature study was performed on the usage of fluid models employed in IFI and it was found that they can be divided into four categories: hydrostatic models, models based on potential flow, models based on Reynolds-averaged Navier–Stokes or a similarly advanced method, and effective fluid models. The hydrostatic models are by far the most prevalent despite only accounting for buoyancy. Most IFI models that account for hydrodynamics make use of potential theory. These models account for fluid flow and surface waves, which together alter the dynamic behavior of floating ice, resulting in hydroelastic effects. The surface-wave-based coupling between ice and floater has not been studied before and there are still open questions regarding the effects of hydroelasticity on the bending failure of ice. The advanced fluid models are a recent trend in IFI and, consequently, most of those are still under development. These models are very promising and may be the future of IFI modeling. Finally, the effective models avoid the practical issues associated with hydrodynamic models in terms of development and calculation time by capturing hydrodynamics in an effective manner, employing, for instance, added mass and damping coefficients. While several studies investigated the efficacy of these models, currently no satisfactory effective fluid model exists. The main goal of this thesis is to further the understanding of how hydrodynamics affects the interaction between ice and a sloping structure and to assess whether it is possible to create an effective model that can replicate the observed effects. The full scope encompasses three smaller studies. First, the surface-wave-based coupling between an elastic ice sheet and nearby floater structure is investigated. This interaction has not been studied before and the solution method that is developed for this problem is also used in the subsequent two studies. Second, a thorough study of the effects of hydrodynamics on the interaction between a sloping structure and level ice is accomplished. This study resulted in the identification of the parameter range wherein hydrostatic models are valid, which is essential given that they constitute the majority of all models. In addition, this study improved the understanding of the effects of hydrodynamics by means of investigating the importance of various components such as the rotational inertia of the ice, axial compression, and the nonlinear hydrodynamic pressure. Furthermore, the relation was analyzed between the temporal development of the contact force and the velocity dependence of the breaking length. Lastly, based on the findings of the second study, an attempt was made to develop an effective fluid model for ice-slope interaction. The efficacy of this model was studied in this thesis for a range of parameters. The main findings of the three studies are summarized next. In the first part of this thesis, the interaction is investigated between an ice floe and a floater through surface waves. This problem is considered first as the Green's functions that are derived for this problem are required for the subsequent studies on ice-slope interaction. The floater is modeled in-plane as a thin rigid body that floats on the surface of a fluid layer of finite depth. On one side of the floater, an ice floe is present which is modeled as a semi-infinite Kirchhoff-Love plate. The floater is excited by external loads and the resulting motions generate waves. Those waves hitting the ice edge are partly transmitted into the ice floe and partly reflected back towards the floater. The reflected waves exert pressure on the floater, altering its response. The resulting motions of the floater were analyzed, revealing several interesting facts. The study showed that below a certain onset frequency, the waves are almost fully transmitted into the ice floe and, consequently, the response of the floater is unaffected by the presence of the ice. The susceptibility of a floater to the waves reflected by a nearby ice floe can thus be estimated by checking how much of its open water response occurs above or below the onset frequency. The onset frequency is sensitive to changes of the ice thickness and insensitive to changes of the Young's modulus and water depth. Above the onset frequency, the waves reflected by the ice have a pronounced effect on the response of the floater. In certain frequency ranges, quasi-standing waves occur within the gap between ice floe and floater. Within these frequency ranges, the response of the floater is significantly altered. Depending on the phasing between the reflected waves and the floater's motions, resonance or anti-resonance can occur which can greatly amplify or reduce the floater's motions when compared to the case when no ice is present. Even when there is no gap between ice and floater, the amplitude of the floater can still be amplified and its natural frequency somewhat increased. The second study of this thesis focuses on the effect of hydrodynamics on the bending failure of an elastic ice floe due to the interaction with a downward-sloping floater, i.e. the effects of hydrodynamics on ice-slope interaction (ISI). A novel, semi-analytical in-plane ISI model is proposed that is based on potential theory in conjunction with the nonlinear Bernoulli equation to describe the fluid pressure. The ice is modeled as a semi-infinite Kirchhoff-Love plate. The predictions of the hydrodynamic model are compared with those of a hydrostatic ISI model, thereby obtaining a quantitative measure of the effect of hydrodynamics on ISI. The comparison revealed several interesting facts. First, the importance of several components of the model was investigated to determine which ones are essential for ISI. It was found that the contribution of the rotational inertia of the ice, axial compression and the nonlinear hydrodynamic pressure is insignificant. Being able to ignore the last two components greatly simplifies the modeling of ISI as it removes all sources of spatial nonlinearity. The terms that were found to be essential for ISI, listed in the order of importance, are: bending of the ice floe, linear hydrodynamic pressure, hydrostatic pressure and the inertia of the ice floe. The contribution of the fluid's inertia is on average four to ten times bigger than that of the inertia of the ice. The study also demonstrated that the effect of wave radiation on ISI is minimal. Second, the relation between the temporal development of the contact force and the velocity-dependence of the breaking length was studied. The study showed that the breaking length has two regimes which are separated by a transition velocity. When the ice velocity is below the transition velocity, the ice fails during the initial impact. Alternatively, when the ice velocity is above the transition velocity, the ice floe survives the impact and fails with a breaking length that is close to the static breaking length. The transition velocity of the hydrodynamic model is much lower than the transition velocity of the hydrostatic model, 0.0725 m/s compared to 0.275 m/s. This major difference in transition velocity is the primary reason for the limited applicability of the hydrostatic model. The results show that the hydrostatic model should not be used when the ice velocity is higher than 0.6 times the transition velocity of the hydrodynamic model as its predictions will deviate significantly, with errors ranging from 30% to 100%. This upper bound corresponds to values between 0.02 m/s and 0.1 m/s for the parameters considered. Lastly, this study underlined the stochastic nature of the breaking length of the ice floe. When the floe fails, a relatively large segment of the floe is, in fact, close to failure. A defect in the ice can locally amplify the stresses, causing the ice to fail at the defect rather than at the location predicted by a homogeneous model. This can cause the breaking length to vary by 10% to 30%. The last part of this thesis builds on the knowledge gained in part two by attempting to create a simple effective fluid model (EFM) that captures the effects of hydrodynamics on ISI as observed in part two. Based on the observations, an EFM is proposed that uses frequency-independent added mass and damping coefficients. This EFM was added to the hydrostatic model, thereby obtaining an ISI model that contains all four essential components of the ISI model. The resulting effective ISI model is very simple and, consequently, its implementation is trivial compared to a true hydrodynamic model such as the one proposed in part two. Its simplicity should help to improve the adoption of hydrodynamics in ISI. The performance of the effective ISI model is assessed. Investigated are the velocity-dependent breaking length, the maximum contact force that occurred during the interaction, and the contact force as a function of time. The predictions of the effective model are far more accurate than those of the hydrostatic model. The coefficients of the EFM were found to be relatively insensitive to changes in the parameters, allowing the effective model to be used for a fairly broad range of parameters.","Hydrodynamics; Hydroelasticity; Ice engineering; Level ice; Bending failure","en","doctoral thesis","","978-94-6384-070-5","","","","","","","","","Offshore Engineering","","",""
"uuid:8111cd63-34b0-4084-a452-94a4a911eea5","http://resolver.tudelft.nl/uuid:8111cd63-34b0-4084-a452-94a4a911eea5","New dynamic-inflow engineering models based on linear and nonlinear actuator disc vortex models","Yu, W. (TU Delft Wind Energy); De Tavernier, D. (TU Delft Wind Energy); Ferreira, Carlos (TU Delft Wind Energy); van Kuik, G.A.M. (TU Delft Wind Energy); Schepers, J.G. (TU Delft Wind Energy; ECN Solar Energy)","","2019","Two new engineering models are presented for the aerodynamic induction of a wind turbine under dynamic thrust. The models are developed using the differential form of Duhamel integrals of indicial responses of actuator disc type vortex models. The time constants of the indicial functions are obtained by the indicial responses of a linear and a nonlinear actuator disc model. The new dynamic-inflow engineering models are verified against the results of a Computational Fluid Dynamics (CFD) model and compared against the dynamic-inflow engineering models of Pitt-Peters, Øye, and Energy Research Center of the Netherlands (ECN), for several load cases. Comparisons of all models show that two time constants are necessary to predict the dynamic induction. The amplitude and phase delay of the velocity distribution shows a strong radial dependency. Verifying the models against results from the CFD model shows that the model based on the linear actuator disc vortex model predicts a similar performance as the Øye model. The model based on the nonlinear actuator disc vortex model predicts the dynamic induction better than the other models concerning both phase delay and amplitude, especially at high load.","actuator disc; CFD; dynamic inflow; engineering model; vortex model","en","journal article","","","","","","","","","","","Wind Energy","","",""
"uuid:e5d0498b-6186-4605-b759-5868fbb0a102","http://resolver.tudelft.nl/uuid:e5d0498b-6186-4605-b759-5868fbb0a102","Testing Industrial-Scale Coral Restoration Techniques: Harvesting and Culturing Wild Coral-Spawn Slicks","Doropoulos, Christopher (Oceans and Atmosphere); Vons, F.J. (TU Delft Civil Engineering & Geosciences; Van Oord Dredging and Marine Contractors B.V.); Elzinga, Jesper (Van Oord Dredging and Marine Contractors B.V.); ter Hofstede, Remment (Van Oord Dredging and Marine Contractors B.V.); Salee, Kinam (Oceans and Atmosphere); van Koningsveld, M. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Van Oord Dredging and Marine Contractors B.V.); Babcock, Russell C. (Oceans and Atmosphere)","","2019","Accelerating the recovery of marine coastal ecosystems is a global challenge that has been attempted on many systems around the world. Restoration efforts have shown varying levels of success at localized-scales, but developing techniques for large-scale application are still in their nascent stage for many systems. For seagrass meadows and marsh plants, large-scale successes have been realized by distributing seeds from moving boats or planes, respectively. Similarly for coral reefs, the harvesting, culturing and releasing of wild coral-spawn slicks to targeted reefs is anticipated to achieve cost-efficient, large-scale restoration of coral communities with low-impact technology. Yet, operational protocols for full-scale application still require development by practitioners. In this study we conducted a field trial to evaluate the actual feasibility of harvesting wild coral-spawn slicks for large-scale restoration activities, incorporating technologies used in oil spill remediation, dredging operations, and land-based aquaculture. Testing the potential for scalability to commercial vessels, our trial focused on concentrating and collecting wild coral-spawn slicks for culturing until settlement competency using an experimental 50,000 L aquaculture facility built on a tugboat. Five objectives were set and all were achieved successfully, with only one requiring further optimization. Overall, this restoration approach allows for long-distance translocation of genetically diverse coral assemblages, and may be combined with other larval conditioning techniques that are being developed to increase the resistance to stress and survival of coral recruits. Most importantly, it is fully scalable to produce billions of coral larvae for delivery to target reefs, with negligible impact to source populations.","aquaculture; coral reef restoration; coral-spawn slick; eco-engineering; Great Barrier Reef; harvest; marine invertebrate larvae; reseeding","en","journal article","","","","","","","","","Civil Engineering & Geosciences","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:97f9e334-435e-4361-9700-b00f7e2f487e","http://resolver.tudelft.nl/uuid:97f9e334-435e-4361-9700-b00f7e2f487e","A platform-based OEM-supplier collaboration ecosystem development","Biahmou, Alain (EDAG AG); Majić, Tomislava (Croatian Academy of Sciences and Arts in Diaspora and Homeland (HAZUDD)); Stjepandić, Josip (PROSTEP AG); Wognum, Nel (TU Delft Air Transport & Operations)","Hiekata, Kazuo (editor); Moser, Brian (editor); Inoue, Masato (editor); Stjepandic, Josip (editor); Wognum, Nel (editor)","2019","Innovative products and services are key success factors for the manufacturing industry. Development of such products and services usually takes place in partnerships in which the original equipment manufacturer (OEM) distributes the development of new products to many locations in several countries across the world. Suppliers, especially first-tier suppliers (FTSs) are involved in the development process as early as possible, because they have knowledge that is strategically important for developing the new product and services. Historically, the OEM-supplier relationship is characterized by a sequential interaction whereby the OEM gives product and production requirements to the supplier and the supplier delivers his product or service to the OEM. However, collaboration between FTS and OEM is essential to fruitfully use the knowledge of the FTS, anticipate potential downstream errors, and reduce costs and risks. The paper presents recent developments in this part of the supply chain with particular attention to the design of a shared platforms, which is part of an OEM-supplier ecosystem. The development process of such an ecosystem can be seen as a transdisciplinary engineering process, because not only IT engineers are needed to build such a platform-base ecosystem but also people with knowledge of supply chain organization and coordination, especially in product development processes.","Data exchange; Ecosystem; Engineering collaboration; PLM; Supplier integration; Supply chain collaboration","en","conference paper","IOS Press","","","","","","","","","","Air Transport & Operations","","",""
"uuid:1de25f4d-c0cb-42d6-9685-d75b300c0aad","http://resolver.tudelft.nl/uuid:1de25f4d-c0cb-42d6-9685-d75b300c0aad","The situated Design Rationale: of a social robot for child's disease self-management","Looije, R. (TU Delft Interactive Intelligence)","Neerincx, M.A. (promotor); Hindriks, K.V. (promotor); Delft University of Technology (degree granting institution)","2019","A young boy with type 1 Diabetes Mellitus is supported by a social robot on the road to self-management. The robot has knowledge on the goals that the boy needs to reach, as discussed with his health care professional. The robot also knows the boy’s activity options and preferences. It suggests activities based on this knowledge, but also encourages the boy to try new approaches. For parents, such a social robot means that they can be less teacher and more parent and for the health care professionals it means they can focus on the emotional aspects instead of the knowledge aspects during visits.
Finally, the boy sees the robot as something that is fun and a peer in contrast to someone/something with a higher authority. The robot supports relatedness and a feeling of competence, the different activities provide a feeling of autonomy, and less budding of the parents reduces stress for the whole family. This all supports that the boy sees diabetesas his own responsibility and feels that he has enough competence and autonomy to take care of diabetes himself. In support of this vision we look in this thesis at the design and evaluation of a social robot.","Social robot; Cognitive engineering; Design rationale; Diabetes; Children","en","doctoral thesis","","978-94-6366-157-7","","","","","","","","","Interactive Intelligence","","",""
"uuid:af94d535-1853-4a6c-8b3f-77c98a52346a","http://resolver.tudelft.nl/uuid:af94d535-1853-4a6c-8b3f-77c98a52346a","Open Aircraft Performance Modeling: Based on an Analysis of Aircraft Surveillance Data","Sun, Junzi (TU Delft Control & Simulation)","Hoekstra, J.M. (promotor); Ellerbroek, Joost (copromotor); Delft University of Technology (degree granting institution)","2019","A large number of stakeholders exist in the modern air traffic management ecosystem. Air transportation studies benefit from collaboration and the sharing of knowledge and findings between these different players. However, not all parties have equal access to information. Due to the lack of open-source tools and models, it is not always possible to undertake comparative studies and to repeat experiments. The barriers to accessing proprietary tools and models create major limitations in the field of air traffic management research. This dissertation investigates the methods necessary to construct an aircraft performance model based on open data, which can be used freely and redistributed without restrictions. The primary data source presented in this dissertation is aircraft surveillance data that can be intercepted openly with little to no restriction in most regions of the world. The eleven chapters in this dissertation follow the sequence of open data, open models, and performance estimations. This order corresponds to the three main parts of the dissertation. In the first part of the dissertation, open surveillance data is explored. Methods are developed to decode and process this data. Extraction of information is also made possible thanks to machine learning algorithms. The second part of the dissertation examines the main components of the open aircraft performance model. Models related to kinematics, thrust, drag polar, fuel flow, and weather are investigated. The third part of the dissertation looks into the possibility of using surveillance data to estimate aircraft performance parameters, for example, aircraft turn performance, aircraft mass, and thrust settings, for individual flights. With the goal of making future air traffic management studies more transparent, comparable, and reproducible, the models and tools proposed in this dissertation are fully open. The final aircraft performance model, OpenAP, proposed in this dissertation has proven to be an efficient open alternative to current closed-source models.","Aircraft Performance; Air Traffic Management; ADS-B; Drag Polar; Dynamic Model; Engine Fuel Flow; Kinematic Model; Meteo-Particle; Mode-S; Open Data; State Estimation; Thrust","en","doctoral thesis","","978-94-6384-030-9","","","","","","2019-12-09","","","Control & Simulation","","",""
"uuid:c8e9b17b-89ea-4faf-b55c-767c1ae070ef","http://resolver.tudelft.nl/uuid:c8e9b17b-89ea-4faf-b55c-767c1ae070ef","20th International Symposium on Aviation Psychology (ISAP 2019)","","Wright State University, Dayton, Ohio, USA (organizer); Air Force Research Laboratory, Wright-Patterson Air Force Base, USA (organizer); Delft University of Technology, Delft, The Netherlands (organizer); Tsang, P.S. (editor); Vidulich, M.A. (editor); van Paassen, M.M. (editor)","2019","The International Symposium on Aviation Psychology is convened for the purposes of: presenting the latest research on human performance problems and opportunities within aviation systems; envisioning design solutions that best utilize human capabilities for creating safe and efficient aviation systems; and bringing together scientists, research sponsors, and operators in an effort to bridge the gap between research and application. Although the symposium is aerospace oriented, we welcome anyone with basic or applied interests in any domain to the extent that generalizations from or to the aviation domain are relevant.","Training; Accident Investigation; Air Traffic Control; Automation; Aviation Psychology; Cognitive Systems Engineering; Decision Making; Display Design; Fatigue; General Aviation; Human Factors; Human-Automation Interaction; Human-Machine Teaming; Multisensory Interaction; Neuroergonomics; Pilot Training; Safety; Selection; Teams","","conference","Delft University of Technology | Wright State University","","","","","","","","","","","","",""
"uuid:609b6589-64bb-4e03-ad53-b04024b281eb","http://resolver.tudelft.nl/uuid:609b6589-64bb-4e03-ad53-b04024b281eb","Producing high-value chemicals in Escherichia coli through synthetic biology and metabolic Engineering","Shomar Monges, H. (TU Delft BN/Greg Bokinsky Lab)","Dogterom, A.M. (promotor); Bokinsky, G.E. (copromotor); Delft University of Technology (degree granting institution)","2019","For millennia, humans have used microbes to produce industrial products of social and economical value through fermentation processes. In recent years, the application of engineering principles to microbiology have dramatically expanded our ability to modify and optimize microbes for the production of a wide variety of commercial products from renewable feedstocks: food and commodity chemicals, to biofuels and fine chemicals such as pharmaceuticals, fragrances, cosmetics or dyes. The use of microbial bioprocesses for the production of natural products represents an attractive and sustainable alternative to current industrial production methods, which mainly rely on chemical synthesis and/ or extraction from native producers. Advanced biomanufacturing technologies would not only provide sustainable economic benefits (by reducing the monetary cost of production of useful chemicals), but also offer social and environmental benefits. Synthetic biology has allowed engineering the production of many industrial compounds within microbes that do not naturally produce them – this is called “heterologous microbial biosynthesis”. In addition to replacing current manufacturing processes, heterologous microbial biosynthesis likely offers the only viable platform to produce certain natural products at industrial scales. Indeed, many relevant compounds cannot be viably manufactured through chemical synthesis, and/or are produced at undetectable/insufficient levels in native organisms. However, many heterologous bioprocesses remain in their infancy to fully enable an economically viable delivery of relevant natural products to the market. In order to build and sustain the promise of a bioeconomy for the 21st century, metabolic engineering is under pressure to continue to provide largescale, sustainable and cost-competitive bioprocesses that meet global needs. In this thesis, we focus on the development of microbial strains to accelerate the microbial production of 2 different families of high-value compounds of prominent biotechnological relevance within the established microbial chassis Escherichia coli: antibiotics and isoprenoids. The fight against antimicrobial resistance is considered one of the greatest public health challenges of the 21st century. Recent technologies have uncovered new antibiotics that, if harnessed, might help alleviate this crisis. However, most of these new antibiotic compounds are far too complex for economical chemical synthesis, and are naturally produced by unculturable and/or genetically intractable microbes. Developing new heterologous microbial platforms for antibiotic production may be an efficient solution for harnessing the clinical potential of these molecules and their commercialization. Isoprenoids represent one of the largest families of natural compounds (over 50,000 molecules) with an incredible number of practical uses, and of great commercial value: from high-value compounds such as many pharmaceuticals, fragrances and flavors, to commodity chemicals such as solvents, rubber or advanced biofuels. We focus in particular on relevant obstacles associated with the development of proof-of-principle strains for the laboratory-scale production of these high-value chemicals.","Synthetic biology; metabolic engineering; biomanufacturing; antibiotics; carbapenems; ironsulfur cluster enzymes; metalloenzymes","en","doctoral thesis","","978-90-8593-386-1","","","","","","","","","BN/Greg Bokinsky Lab","","",""
"uuid:ea1b4101-0e55-4abe-9539-ae5d81cf9f65","http://resolver.tudelft.nl/uuid:ea1b4101-0e55-4abe-9539-ae5d81cf9f65","A guideline for selecting MDAO workflows with an application in offshore wind energy","Sanchez Perez Moreno, S. (TU Delft Wind Energy)","van Bussel, G.J.W. (promotor); Zaaijer, M B (copromotor); Delft University of Technology (degree granting institution)","2019","A system is a set of interconnected components whose individual behaviour and interactions determine the overall performance of the set. Wind farms are amongst the most complex systems deployed worldwide, based on their uncertainty, heterogeneity and complexity. Moreover, many technical and social disciplines may simultaneously describe the performance of a complex system such as wind farms.","Offshore wind farm design; systems engineering; MDAO workflows","en","doctoral thesis","","978-94-6366-138-6","","","","","","","","","Wind Energy","","",""
"uuid:b36407d1-b5ff-4825-9318-f36124f08e7b","http://resolver.tudelft.nl/uuid:b36407d1-b5ff-4825-9318-f36124f08e7b","Pragmatic software testing education","Aniche, Maurício (TU Delft Software Engineering); Hermans, F.F.J. (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology)","","2019","Software testing is an important topic in software engineering education, and yet highly challenging from an educational perspective: students are required to learn several testing techniques, to be able to distinguish the right technique to apply, to evaluate the quality of their test suites, and to write maintainable test code. In this paper, we describe how we have been adding a pragmatic perspective to our software testing course, and explore students' common mistakes, hard topics to learn, favourite learning activities, and challenges they face. To that aim, we analyze the feedback reports that our team of Teaching Assistants gave to the 230 students of our 2016-2017 software testing course at Delft University of Technology. We also survey 84 students and seven of our teaching assistants on their perceptions. Our results help educators not only to propose pragmatic software testing courses in their faculties, but also bring understanding on the challenges that software testing students face when taking software testing courses.","Computer science education; Software engineering education; Software testing education","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:d12efaac-4ef6-459e-ac79-103f7c24f526","http://resolver.tudelft.nl/uuid:d12efaac-4ef6-459e-ac79-103f7c24f526","Discovering Community Patterns in Open-Source: A Systematic Approach and Its Evaluation","Tamburri, Damian A. (Eindhoven University of Technology); Palomba, F. (University of Zürich); Serebrenik, Alexander (Eindhoven University of Technology); Zaidman, A.E. (TU Delft Software Engineering)","","2019","“There can be no vulnerability without risk; there can be no community without vulnerability; there can be no peace, and ultimately no life, without community.” - [M. Scott Peck]
The open-source phenomenon has reached the point in which it is virtually impossible to find large applications that do not rely on it. Such grand adoption may turn into a risk if the community regulatory aspects behind open-source work (e.g., contribution guidelines or release schemas) are left implicit and their effect untracked. We advocate the explicit study and automated support of such aspects and propose Yoshi (Y ielding O pen-S ource H ealth I nformation), a tool able to map open-source communities onto community patterns, sets of known organisational and social structure types and characteristics with measurable core attributes. This mapping is beneficial since it allows, for example, (a) further investigation of community health measuring established characteristics from organisations research, (b) reuse of pattern-specific best-practices from the same literature, and (c) diagnosis of organisational anti-patterns specific to open-source, if any. We evaluate the tool in a quantitative empirical study involving 25 open-source communities from GitHub, finding that the tool offers a valuable basis to monitor key community traits behind open-source development and may form an effective combination with web-portals such as OpenHub or Bitergia. We made the proposed tool open source and publicly available.","Community patterns; Community types; Empirical software engineering; Open source systems and community analysis","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:05f40c8a-c7a5-436b-963b-a82346ca8bc7","http://resolver.tudelft.nl/uuid:05f40c8a-c7a5-436b-963b-a82346ca8bc7","Does reviewer recommendation help developers?","Kovalenko, V.V. (TU Delft Software Engineering); Tintarev, N. (TU Delft Web Information Systems); Pasynkov, Evgeny (JetBrains); Bird, Christian (Microsoft Research); Bacchelli, A. (University of Zürich)","","2019","Selecting reviewers for code changes is a critical step for an efficient code review process. Recent studies propose automated reviewer recommendation algorithms to support developers in this task. However, the evaluation of recommendation algorithms, when done apart from their target systems and users (i.e., code review tools and change authors), leaves out important aspects: perception of recommendations, influence of recommendations on human choices, and their effect on user experience. This study is the first to evaluate a reviewer recommender in vivo. We compare historical reviewers and recommendations for over 21,000 code reviews performed with a deployed recommender in a company environment and set out to measure the influence of recommendations on users' choices, along with other performance metrics. Having found no evidence of influence, we turn to the users of the recommender. Through interviews and a survey we find that, though perceived as relevant, reviewer recommendations rarely provide additional value for the respondents. We confirm this finding with a larger study at another company. The confirmation of this finding brings up a case for more user-centric approaches to designing and evaluating the recommenders. Finally, we investigate information needs of developers during reviewer selection and discuss promising directions for the next generation of reviewer recommendation tools. Preprint: https://doi.org/10.5281/zenodo.1404814.","Code review; empirical software engineering; reviewer recommendation","en","journal article","","","","","","This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication.","","","","","Software Engineering","","",""
"uuid:40c6d9d9-5d3e-48f9-ba7b-dea21d6af1ce","http://resolver.tudelft.nl/uuid:40c6d9d9-5d3e-48f9-ba7b-dea21d6af1ce","Fine-grained just-in-time defect prediction","Pascarella, L. (TU Delft Software Engineering); Palomba, F. (University of Zürich); Bacchelli, A. (University of Zürich)","","2019","Defect prediction models focus on identifying defect-prone code elements, for example to allow practitioners to allocate testing resources on specific subsystems and to provide assistance during code reviews. While the research community has been highly active in proposing metrics and methods to predict defects on long-term periods (i.e.,at release time), a recent trend is represented by the so-called short-term defect prediction (i.e.,at commit-level). Indeed, this strategy represents an effective alternative in terms of effort required to inspect files likely affected by defects. Nevertheless, the granularity considered by such models might be still too coarse. Indeed, existing commit-level models highlight an entire commit as defective even in cases where only specific files actually contain defects. In this paper, we first investigate to what extent commits are partially defective; then, we propose a novel fine-grained just-in-time defect prediction model to predict the specific files, contained in a commit, that are defective. Finally, we evaluate our model in terms of (i) performance and (ii) the extent to which it decreases the effort required to diagnose a defect. Our study highlights that: (1) defective commits are frequently composed of a mixture of defective and non-defective files, (2) our fine-grained model can accurately predict defective files with an AUC-ROC up to 82% and (3) our model would allow practitioners to save inspection efforts with respect to standard just-in-time techniques.","Empirical Software Engineering; Just-in-time defect prediction; Mining software repositories","en","journal article","","","","","","","","2021-01-16","","","Software Engineering","","",""
"uuid:51cc4168-767d-49e0-85c7-23b330deb944","http://resolver.tudelft.nl/uuid:51cc4168-767d-49e0-85c7-23b330deb944","Expert judgement based maintenance decision support method for structures with a long service-life","Ter Berg, C.J.A. (Student TU Delft); Leontaris, G. (TU Delft Integral Design & Management); van den Boomen, M. (TU Delft Integral Design & Management); Spaan, M.T.J. (TU Delft Algorithmics); Wolfert, A.R.M. (TU Delft Integral Design & Management)","","2019","The optimal moment at which maintenance activities should be performed on structures with long service-life to guarantee the required quality of service is hard to define, due to uncertainties in their deterioration processes. Most of the developed methods and concepts use historical data to predict the deterioration process with deterministic values as a result. Some researchers recognise that probabilistic deterioration models are required for life-cycle models but in practice, however, historical data are often scarce. Moreover, the available data often only inform about a short period of time, while maintenance strategies, technologies, materials and external circumstances change over time. Therefore, the required probabilistic deterioration models cannot be retrieved and remain unproven in life-cycle modelling so far. Hence, this article introduces an expert judgement based Condition Over Time Assessment method that quantifies the uncertainty regarding the period that is required for structural assets to deteriorate to a given condition. The proposed method utilises Cooke’s classical model, which makes use of knowledge and experience of experts, who are weighed according to their performance in judging uncertainty, to assess this period. A bridge-based experiment shows that the proposed method has the potential to provide a means to effectively plan maintenance.","Deterioration modelling; engineering asset management; expert judgement; maintenance interval; uncertainty quantification","en","journal article","","","","","","","","","","","Integral Design & Management","","",""
"uuid:fb65f714-1771-4446-9114-73ee302d5693","http://resolver.tudelft.nl/uuid:fb65f714-1771-4446-9114-73ee302d5693","Current Challenges in Practical Object-Oriented Software Design","Aniche, Maurício (TU Delft Software Engineering); Yoder, Joseph W. (The Refactory); Kon, Fabio (Universidade de São Paulo)","Kellenberger, P. (editor)","2019","According to the extensive 50-year-old body of knowledge in object-oriented programming and design, good software designs are, among other characteristics, lowly coupled, highly cohesive, extensible, comprehensible, and not fragile. However, with the increased complexity and heterogeneity of contemporary software, this might not be enough. This paper discusses the practical challenges of object-oriented design in modern software development. We focus on three main challenges: (1) how technologies, frameworks, and architectures pressure developers to make design decisions that they would not take in an ideal scenario, (2) the complexity of current real-world problems require developers to devise not only a single, but several models for the same problem that live and interact together, and (3) how existing quality assessment techniques for object-oriented design should go beyond high-level metrics. Finally, we propose an agenda for future research that should be tackled by both scientists and practitioners soon. This paper is a call for arms for more reality-oriented research on the object-oriented software design field.","Class design; Domain modeling; Object oriented design; Object oriented programming; Software architecture; Software design; Software engineering","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Software Engineering","","",""
"uuid:6fcaa1db-7e3a-4546-8329-1cc69901df7e","http://resolver.tudelft.nl/uuid:6fcaa1db-7e3a-4546-8329-1cc69901df7e","Lessons learned from developing mbeddr: a case study in language engineering with MPS","Völter, Markus (Itemis AG); Kolb, Bernd (Itemis AG); Szabo, T. (TU Delft Programming Languages; Itemis AG); Ratiu, Daniel (Siemens AG); van Deursen, A. (TU Delft Software Technology)","","2019","Language workbenches are touted as a promising technology to engineer languages for use in a wide range of domains, from programming to science to business. However, not many real-world case studies exist that evaluate the suitability of language workbench technology for this task. This paper contains such a case study. In particular, we evaluate the development of mbeddr, a collection of integrated languages and language extensions built with the Jetbrains MPS language workbench. mbeddr consists of 81 languages, with their IDE support, 34 of them C extensions. The mbeddr languages use a wide variety of notations---textual, tabular, symbolic and graphical---and the C extensions are modular; new extensions can be added without changing the existing implementation of C. mbeddr's development has spanned 10 person-years so far, and the tool is used in practice and continues to be developed. This makes mbeddr a meaningful case study of non-trivial size and complexity. The evaluation is centered around five research questions: language modularity, notational freedom and projectional editing, mechanisms for managing complexity, performance and scalability issues and the consequences for the development process. We draw generally positive conclusions; language engineering with MPS is ready for real-world use. However, we also identify a number of areas for improvement in the state of the art in language engineering in general, and in MPS in particular.","Language engineering; Language extension; Language workbenches; Domain-specific language; Case study; Languages; Experimentation","en","journal article","","","","","","","","2019-03-01","","Software Technology","Programming Languages","","",""
"uuid:f292940d-8ab0-49a2-a5ba-289ee50bb85f","http://resolver.tudelft.nl/uuid:f292940d-8ab0-49a2-a5ba-289ee50bb85f","Implementation of non-trivial boundary conditions in MPM for geotechnical applications","Remmerswaal, G. (TU Delft Geo-engineering); Bolognin, M. (TU Delft Hydraulic Structures and Flood Risk); Vardon, P.J. (TU Delft Geo-engineering); Hicks, M.A. (TU Delft Geo-engineering); Rohe, A. (Deltares)","","2019","This paper describes current work on the implementation of non-trivial boundary conditions (BCs) for improving the general applicability of the Material Point Method (MPM) to geotechnical boundary values problems. It summarises novel boundary treatments (non-trivial BCs) in MPM for (i) flow conditions, as well as (ii) the application of a surface traction on a moving boundary for solid materials. Both treatments are required, for example, to estimate the consequence of slope failure in geotechnical engineering. the flow condition BCs have been used to stimulate a subcritical flow and the surface traction BC has been applied on top of aslope leading to failure. Both examples show that these new treatments are useful in solving practical problems.","Boundary conditions; Geotechnical engineering practice; Material Point Method; Slope Stability","en","conference paper","","","","","","","","","","","Geo-engineering","","",""
"uuid:68b47b23-50d9-4b38-9e8b-40b791958492","http://resolver.tudelft.nl/uuid:68b47b23-50d9-4b38-9e8b-40b791958492","Modelling the cyclic ratcheting of sands through memory-enhanced bounding surface plasticity","Liu, H. (TU Delft Geo-engineering); Abell, J. A. (Universidad de los Andes); Diambra, A. (University of Bristol); Pisano, F. (TU Delft Geo-engineering)","","2019","The modelling and simulation of cyclic sand ratcheting is tackled by means of a plasticity model formulated within the well-known critical state, bounding surface SANISAND framework. For this purpose, a third locus – termed the ‘memory surface’ – is cast into the constitutive formulation, so as to phenomenologically capture micro-mechanical, fabric-related processes directly relevant to the cyclic response. The predictive capability of the model under numerous loading cycles (‘high-cyclic’ loading) is explored with focus on drained loading conditions, and validated against experimental test results from the literature – including triaxial, simple shear and cyclic loading by oedometer test. The model proves capable of reproducing the transition from ratcheting to shakedown response, in combination with a single set of soil parameters for different initial, boundary and loading conditions. This work contributes to the analysis of soil–structure interaction under high-cyclic loading events, such as those induced by environmental and/or traffic loads.","constitutive relations; numerical modelling; offshore engineering; plasticity; sands; stiffness","en","journal article","","","","","","Accepted Author Manuscript","","2019-10-10","","","Geo-engineering","","",""
"uuid:193d2d6a-9429-49e5-958f-f7ef1900a974","http://resolver.tudelft.nl/uuid:193d2d6a-9429-49e5-958f-f7ef1900a974","Quantitative Modeling of the Effect of Oil on Foam for Enhanced Oil Recovery","Tang, J. (TU Delft Reservoir Engineering); Ansari, Mohammed N. (Student TU Delft); Rossen, W.R. (TU Delft Reservoir Engineering)","","2019","The effectiveness of foam for mobility control in the presence of oil is key to foam enhanced oil recovery (EOR). A fundamental property of foam EOR is the existence of two steady-state flow regimes: the high-quality regime and the low-quality regime. Experimental studies have sought to understand the effect of oil on foam through its effect on these two regimes. Here, we explore the effect of oil on the two flow regimes for one widely used foam model. The STARS (CMG 2015) foam model includes two algorithms for the effect of oil on foam: In the “wet-foam” model, oil changes the mobility of full-strength foam in the low-quality regime, and in the “dry-out” model, oil alters the limiting water saturation around which foam collapses. We examine their effects as represented in each model on the two flow regimes using a Corey relative permeability function for oil. Specifically, we plot the pressure-gradient contours that define the two flow regimes as a function of superficial velocities of water, gas, and oil, and show how oil shifts behavior in the regimes. The wet-foam model shifts behavior in the low-quality regime with no direct effect on the high-quality regime. The dry-out model shifts behavior in the high-quality regime but not the low-quality regime. At fixed superficial velocities, both models predict multiple steady states at some injection conditions. We perform a stability analysis of these states using a simple 1D simulator with and without incorporating capillary diffusion. The steady state attained after injection depends on the initial state. In some cases, it appears that the steady state at the intermediate pressure gradient is inherently unstable, as represented in the model. In some cases, the introduction of capillary diffusion is required to attain a uniform steady state in the medium. The existence of multiple steady states, with the intermediate one being unstable, is reminiscent of catastrophe theory and of studies of foam generation without oil.","Energy Engineering and Power Technology; Geotechnical Engineering and Engineering Geology","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-07-28","","","Reservoir Engineering","","",""
"uuid:3002d98e-485b-4828-9a47-46f92bc8e815","http://resolver.tudelft.nl/uuid:3002d98e-485b-4828-9a47-46f92bc8e815","Empowering through reflection: participatory design of change in agricultural chains in Indonesia by local stakeholders","Kusnandar, K. (TU Delft System Engineering); van Kooten, O. (Wageningen University & Research); Brazier, F.M. (TU Delft System Engineering)","","2019","Participation of local actors has shown to be of significant importance to the uptake of new approaches to agricultural initiatives in developing countries. This paper proposes a new approach to empower local chain actors to work together to understand their own and others’ challenges, to pursue common understanding of their situations and challenges, and to then co-create solutions. Reflection on each other’s position is crucial to this process, and is core to the participatory approach designed to this purpose. Agricultural chains are the focus of a case study in Indonesia involving both farmers and wholesalers in the chain. Results show that the approach has led to new forms of collaboration between farmers, and between farmers and wholesalers, increasing market potential.","Food Science & Technology; Engineering & Technology; Design; Collaborative Design; Rural Development; OA-Fund TU Delft; empowerment; co-creation; reflection; developing countries; participatory; agricultural chains","en","journal article","","","","","","","","","","","System Engineering","","",""
"uuid:19fe83c4-a4ee-4602-9c6d-2c374b917459","http://resolver.tudelft.nl/uuid:19fe83c4-a4ee-4602-9c6d-2c374b917459","Joint faulting behaviour of innovative short concrete slabs","Pradena, Mauricio (University of Concepcion); Houben, L.J.M. (TU Delft Pavement Engineering)","","2019","Pavements are one of the largest assets of a city and their functional condition (ride quality) is priority for their clients. In jointed plain concrete pavements (JPCPs), the presence of joint faulting (JF) reduces the ride quality. Today, short slabs are available as a cost-effective JPCP innovation. The objective of this paper is to analyse the JF behaviour of JPCPs with short slabs. For this, a deterioration model to predict it and trends of JF observed in short slabs of Chile and the United States are considered. The HDM-4 model always yields lower JF per joint in short slabs than in traditional ones. However, real-world short slabs show not only lower JF per joint (that the modelled JF), but also that more joints do not necessarily mean more JF per length of pavement that affect the ride quality. One of the relevant explanatory factors for it is the radical reduction of crack width at joints, which produces a fundamental increase of the load transfer efficiency. To maintain favourable behaviour observed in the field it is recommended to assure joint activation and to provide adequate stiffness of the layers below the short slabs.","Highways; Municipal; Pavement design; Public service engineering; Roads","en","journal article","","","","","","","","2019-08-23","","","Pavement Engineering","","",""
"uuid:c7c25b81-835a-4059-b30e-d0a9d49a959b","http://resolver.tudelft.nl/uuid:c7c25b81-835a-4059-b30e-d0a9d49a959b","A CFD approach for the flotation analysis of pipelines in liquefied sand (Une approche CFD pour l’étude de la flottation des pipelines dans les sables liquéfiés)","Pisano, F. (TU Delft Geo-engineering); Cremonesi, Massimiliano (Politecnico di Milano); Bortolotto, F. (Polytecnico di Milano); Della Vecchia, Gabriele (Politecnico di Milano)","Sigursteinsson, Haraldur (editor); Erlingsson, Sigurður (editor); Bessason, Bjarni (editor)","2019","Submarine buried pipelines may often interact with shallow layers of loose sand that are particularly prone to liquefaction. When liquefaction is triggered by environmental loading and/or mechanical vibrations, the soil tends to behave as a viscous solid-fluid mixture and the pipeline to undergo either flotation or sinking. While a few indications can be found in the literature on the triggering condition for flotation/sinking, no conclusive methods are available to estimate the displacement of the pipe when liquefaction cannot be avoided. This preliminary work shows that combining in numerical simulations fluid and soil mechanics may successfully serve such a goal. The proposed modelling approach is compared to the results of small-scale pipe flotation tests, with emphasis on existing knowledge gaps and indications for future research on the subject.","Consolidation; Finite element modelling; Liquefaction; Offshore engineering; Pipes & pipelines","en","conference paper","Icelandic Geotechnical Society (IGS)","","","","","Accepted Author Manuscript","","","","","Geo-engineering","","",""
"uuid:040b57df-e74a-4850-acf8-7f73730d7d47","http://resolver.tudelft.nl/uuid:040b57df-e74a-4850-acf8-7f73730d7d47","Grand Research Challenges for Sustainable Industrial Biotechnology","Straathof, Adrie J.J. (TU Delft BT/Bioprocess Engineering); Wahl, S.A. (TU Delft OLD BT/Cell Systems Engineering); Benjamin, Kirsten R. (Amyris Inc); Takors, Ralf (University of Stuttgart); Wierckx, Nick (Forschungszentrum Jülich GmbH); Noorman, H.J. (TU Delft BT/Bioprocess Engineering; DSM)","","2019","Future manufacturing will focus on new, improved products as well as on new and enhanced production methods. Recent biotechnological and scientific advances, such as CRISPR/Cas and various omic technologies, pave the way to exciting novel biotechnological research, development, and commercialization of new sustainable products. Rigorous mathematical descriptions of microbial cells and consortia thereof will enable deeper biological understanding and lead to powerful in silico cellular models. Biological engineering, namely model-based design together with synthetic biology, will accelerate the construction of robust and high-performing microorganisms. Using these organisms, and ambitions towards zero-concepts with respect to emissions and excess resources in bioprocess engineering, industrial biotechnology is expected to become highly integrated into sustainable generations of technology systems.","bio-based production; biological engineering; bioprocess engineering; industrial fermentation; systems biotechnology","en","review","","","","","","Accepted Author Manuscript","","2020-05-01","","","BT/Bioprocess Engineering","","",""
"uuid:4ce60caa-58a6-4721-86c0-bd80525443a3","http://resolver.tudelft.nl/uuid:4ce60caa-58a6-4721-86c0-bd80525443a3","Three Approaches to Design Engineering in the Health Domain: A Systemic Perspective","Pannunzio, V. (TU Delft Methodologie en Organisatie van Design); Kleinsmann, M.S. (TU Delft Methodologie en Organisatie van Design); Snelders, H.M.J.J. (TU Delft Methodologie en Organisatie van Design)","Schaub, Petra Badke (editor); Kleinsmann, Maaike (editor)","2019","This paper proposes a categorization of existing approaches to healthcare-related engineering design based on systems thinking principles. Three existing approaches to healthcare-related engineering design are isolated which contribute differently to health systems fundamental purposes and interconnections. The three approaches are labeled as 'silent', 'overt', and 'convergent' health design. Each approach is defined and illustrated through an example. Following, practical advantages and disadvantages of each approach are discussed. A reflection is offered on the expected relevance of the convergent health design approach for present and future societal challenges in the health domain, and specifically on the recently growing field of e-health. Finally, open methodological challenges related to convergent health design are outlined and characterized as opportunities for future research.","Biomedical design; E-Health; Participatory design; Systems Engineering (SE); Systems thinking","en","conference paper","Cambridge University Press","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:3ad6a756-4dfd-40a5-a888-c382be3f21db","http://resolver.tudelft.nl/uuid:3ad6a756-4dfd-40a5-a888-c382be3f21db","Star Tag: a superhuman sport to promote physical activity","Numan, Nels (Student TU Delft); Kolster, Ayla (Student TU Delft); Hoogerwerf, Niels (Student TU Delft); Kreynen, Bernd (Student TU Delft); Romeijnders, Jeanique (Student TU Delft); Heinsohn Huala, Tomas (Student TU Delft); Ziliotto Salamon, N. (TU Delft Computer Graphics and Visualisation); Balint, J.T. (TU Delft Computer Graphics and Visualisation); Lukosch, S.G. (TU Delft System Engineering); Bidarra, Rafael (TU Delft Computer Graphics and Visualisation)","","2019","Superhuman sports (SHS) is a field where technological augmentations of human abilities and environment are combined to play a new and exciting sport. SHS make use of artificial senses or virtual reality to create a new experience that involves physical fitness and skills. Star Tag aims to combine these aspects with an engaging audience experience. This augmented reality game uses the Microsoft HoloLens, making it possible to move through a mixed reality space effectively. Star Tag is a competitive multiplayer game where players need to conquer all planets from their opponent to win the game. Players need to move around in a physical space from virtual planet to virtual planet in order to navigate the game-space and reach the planets. The audience is involved with the game via their phones, through which they can support the players. Through playtesting and conducting a survey, the results show that Star Tag is a superhuman sport that motivates people to be physically active.","Human-centered computing; Mixed / augmented reality Human-centered computing; User studies Human-centered computing; User interface design Software and its engineering; Interactive games","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","","","","Computer Graphics and Visualisation","","",""
"uuid:753be0b5-6011-410f-92f4-45b7e0b94b62","http://resolver.tudelft.nl/uuid:753be0b5-6011-410f-92f4-45b7e0b94b62","Superhuman sports in mixed reality: The multi-player game League of Lasers","Miedema, Nico Arjen (Student TU Delft); Vermeer, Jop (Student TU Delft); Lukosch, S.G. (TU Delft System Engineering); Bidarra, Rafael (TU Delft Computer Graphics and Visualisation)","","2019","In recent years, many promising developments have taken place around augmented, virtual and mixed-reality technology. One could wonder whether these technologies can be combined to yield a mix of video games and sports, involving physical activities previously deemed impossible: creating a superhuman sport. This work investigates how mixed-reality can be used to create a fun, intuitive and engaging superhuman sport. To this end, the game League of Lasers was developed, in which two teams compete in a mix between football and Pong, using the physical movement of the players as main means to interact within mixed-reality. An evaluation of League of Lasers with a user study with 32 participants showed that League of Lasers is perceived as a fun and immersive skill-based game.","Human-centered computing; Mixed / augmented reality Human-centered computing; User studies Human-centered computing; User interface design Software and its engineering; Interactive games","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-02-15","","","System Engineering","","",""
"uuid:c3386b2b-85aa-4107-8a9f-a4c136f13dd7","http://resolver.tudelft.nl/uuid:c3386b2b-85aa-4107-8a9f-a4c136f13dd7","The Effect of Soil-Vegetation-Atmosphere Interaction on Slope Stability: A Numerical Study","Jamalinia, E. (TU Delft Geo-engineering); Vardon, P.J. (TU Delft Geo-engineering); Steele-Dunne, S.C. (TU Delft Water Resources)","","2019","The stability of a dike is influenced strongly by its water content, by way of changes in effective stress and weight. While flow through porous media is relatively well understood, water flux in and out of a dike through a vegetated surface is not as well understood. This paper presents a numerical study of the soil-vegetation-atmosphere interaction and discusses how it influences the stability of dikes covered with grass. A crop model was used to simulate vegetation growth and infiltration in response to meteorological forcing. The PLAXIS finite-element method model was used to simulate the impact of this infiltration on hydromechanical behaviour and dike stability. Results from a 4-year analysis indicated a strong correlation between root zone water content (WC rz) and factor of safety, although the relationship is not unique. The leaf area index (LAI) was also found to have a strong, lagged correlation with the water flux into the dike. This suggests that monitoring LAI could be a useful tool to identify vulnerable locations along dikes. It is therefore proposed that vegetation and root zone water content could be used as an indication to detect vulnerable dikes in the early stage.","Slope Stability; Vegetation; Seepage; Geotechnical engineering; Slopes-stabilization","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-03-02","","","Geo-engineering","","",""
"uuid:88f9c01f-eae2-4514-b49b-c3a388eeda53","http://resolver.tudelft.nl/uuid:88f9c01f-eae2-4514-b49b-c3a388eeda53","Monitoring-aware IDEs","Winter, J. (Adyen B.V.); Aniche, Maurício (TU Delft Software Engineering); Cito, Jürgen (Massachusetts Institute of Technology); van Deursen, A. (TU Delft Software Technology)","","2019","Engineering modern large-scale software requires software developers to not solely focus on writing code, but also to continuously examine monitoring data to reason about the dynamic behavior of their systems. These additional monitoring responsibilities for developers have only emerged recently, in the light of DevOps culture. Interestingly, software development activities happen mainly in the IDE, while reasoning about production monitoring happens in separate monitoring tools. We propose an approach that integrates monitoring signals into the development environment and workflow. We conjecture that an IDE with such capability improves the performance of developers as time spent continuously context switching from development to monitoring would be eliminated. This paper takes a first step towards understanding the benefits of a possible monitoring-aware IDE. We implemented a prototype of a monitoring-aware IDE, connected to the monitoring systems of Adyen, a large-scale payment company that performs intense monitoring in their software systems. Given our results, we firmly believe that monitoring-aware IDEs can play an essential role in improving how developers perform monitoring.","software engineering; devops; systems monitoring; runtime monitoring; integrated development environment; ide","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:70acc8f1-6e5d-4fcf-acbd-c6bacec61b06","http://resolver.tudelft.nl/uuid:70acc8f1-6e5d-4fcf-acbd-c6bacec61b06","JCOMIX: a Search-based Tool to Detect XML Injection Vulnerabilities inWeb Applications: A search-based tool to detect XML injection vulnerabilities in web applications","Stallenberg, Dimitri Michel (Student TU Delft); Panichella, A. (TU Delft Software Engineering)","Apel, Sven (editor); Dumas, Marlon (editor); Russo, Alessandra (editor); Pfahl, Dietmar (editor)","2019","Input sanitization and validation of user inputs are well-established protection mechanisms for microservice architectures against XML injection attacks (XMLi). The effectiveness of the protection mechanisms strongly depends on the quality of the sanitization and validation rule sets (e.g., regular expressions) and, therefore, security analysts have to test them thoroughly. In this demo, we introduce JCOMIX, a penetration testing tool that generates XMLi attacks (test cases) exposing XML vulnerabilities in front-end web applications. JCOMIX implements various search algorithms, including random search (traditional fuzzing), genetic algorithms (GAs), and the more recent co-operative, co-evolutionary algorithm designed explicitly for the XMLi testing (COMIX). We also show the results of an empirical study showing the effectiveness of JCOMIX in testing an open-source front-end web application.","Search-based Software Engineering; Security Testing; Test Case Generation; XML injection","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Software Engineering","","",""
"uuid:e79aac89-295c-413b-9ca1-1140ddd3db14","http://resolver.tudelft.nl/uuid:e79aac89-295c-413b-9ca1-1140ddd3db14","An Empirical Catalog of Code Smells for the Presentation Layer of Android Apps","Goularte Carvalho, Suelen (Universidade de São Paulo); Aniche, Maurício (TU Delft Software Engineering); Veríssimo, Júlio (Federal University of Lavras); Durelli, Rafael (Universidade Federal de Lavras); Gerosa, Marco Aurélio (Northern Arizona University)","","2019","Software developers, including those of the Android mobile platform, constantly seek to improve their applications’ maintainability and evolvability. Code smells are commonly used for this purpose, as they indicate symptoms of design problems. However, although the literature presents a variety of code smells, such as God Class and Long Method, characteristics that are specific to the underlying technologies are not taken into account. The presentation layer of an Android app, for example, implements specific architectural decisions from the Android platform itself (such as the use of Activities, Fragments, and Listeners) as well as deal with and integrate different types of resources (such as layouts and images). Through a three-step study involving 246 Android developers, we investigated code smells that developers perceive for this part of Android apps. We devised 20 specific code smells and collected the developers’ perceptions of their frequency and importance. We also implemented a tool that identifies the proposed code smells and studied their prevalence in 619 open-source Android apps. Our findings suggest that: 1) developers perceive smells specific to the presentation layer of Android apps; 2) developers consider these smells to be of high importance and frequency; and 3) the proposed smells occur in real-world Android apps. Our domain-specific smells can be leveraged by developers, researchers, and tool developers for searching potentially problematic pieces of code.","Android mobile applications; Code smells; Empirical software engineering; Software maintenance and evolution","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:c6f884dd-1556-4408-99d8-98d8d6230c90","http://resolver.tudelft.nl/uuid:c6f884dd-1556-4408-99d8-98d8d6230c90","Contributing human and organizational factors for the failure of balconies in Maastricht","Terwel, K.C. (TU Delft Applied Mechanics)","","2019","In 2003 five balconies of an apartment building in Maastricht, the Netherlands, collapsed, resulting in two fatalities. The building was just completed.
Forensic investigations showed that detailing of the reinforcement in the precast concrete slabs of the balconies was questionable. Several design changes hampered clear force flow through the structural elements. Inappropriate design fixes were made after discovery of some cracks that could not avoid failure of a lower concrete ridge, resulting in a progressive collapse of the 5 balconies.
Profound investigation of this case showed various human and organizational factors, that might have contributed to the failure. A complex process, with several design changes and many involved parties increased the probability of failure. Furthermore, insufficient communication, inadequate checking and inadequate follow up to warnings were present.
This paper will give insight in technical causes of the failure and of contributing human and organizational factors. These underlying factors will be systematically studied, by using a theoretical framework.","Forensic structural engineering; Human; Organizational factors; Structural failure","en","conference paper","","","","","","Accepted Author Manuscript","","","","","Applied Mechanics","","",""
"uuid:d94688bb-fa94-4cea-b723-8754b28e8bc0","http://resolver.tudelft.nl/uuid:d94688bb-fa94-4cea-b723-8754b28e8bc0","Operational range of a ferrofluid pocket bearing","Boots, Jelle (Student TU Delft); Spronck, J.W. (TU Delft Mechatronic Systems Design); van Ostayen, R.A.J. (TU Delft Mechatronic Systems Design); Lampaert, S.G.E. (TU Delft Mechatronic Systems Design)","","2019","Ferrofluid pocket bearings are interesting for fast and precise positioning systems thank to the absence of stick-slip, the low viscous friction and their cost-effective nature. However, the characteristics of the bearing change due to over(de)compression since air escapes out of the enclosed pocket. This article presents an experimentally validated model that includes the air mass inside the pocket in the calculation of the equilibrium position of the ferrofluid bearing. Moreover, a simple and efficient way to obtain the operational range of the bearing is presented and a sensitivity analysis was performed. The sensitivity analysis showed that ferrofluid pocket bearings are always self-aligning and that the tilt stiffness increases when the fly height decreases or the tilt angle increases.","Precision engineering; FEM modelling; mathematical modelling; hydrostatic bearing; magnetics; sensitivity analysis","en","journal article","","","","","","","","","","","Mechatronic Systems Design","","",""
"uuid:486540dc-4554-4313-999e-c4c7b1d6c0f4","http://resolver.tudelft.nl/uuid:486540dc-4554-4313-999e-c4c7b1d6c0f4","Communication Activity Implementation over 3 Engineering Universities: Values and Challenges","Leandro Cruz, M. (TU Delft Novel Aerospace Materials); Carthy, D (Technological University Dublin); Craps, S. (Katholieke Universiteit Leuven)","","2019","The urgency to stimulate transversal competencies is evident and acknowledged by accreditation commissions and institutions. For this reason, higher engineering education has developed practices and implemented in the engineering curricula elements that stimulate these competencies. However, educators find difficulties in developing and implementing them due to lack of time or experience, space in the degrees, or lack of institution support. This study describes a communication activity created and implemented over three engineering education institutions as part of a European knowledge alliance project and presents the values and challenges experienced by the universities after its implementation. Students carried out a short questionnaire at the end of the activity and the data from the three institutions were compared. The findings of this study showed that students perceived that this communication activity helped them to understand the importance of communication skills, and because of its nature of plug and play it was easily transferable to the three universities. This study provides educators with a new educational practice easy to implement and effective to stimulate student reflection on their communication skills.","Curriculum elements; engineering education; communication skills; values; challenges","en","conference paper","","","","","","","","","","","Novel Aerospace Materials","","",""
"uuid:6c7fb1f6-f472-4923-99f1-3ec81a00daec","http://resolver.tudelft.nl/uuid:6c7fb1f6-f472-4923-99f1-3ec81a00daec","Experimental investigation of the wave-induced motion of and force distribution along a flexible stem","Jacobsen, Niels G. (Deltares); Bakker, Wout (Deltares; EcoFlows); Uijttewaal, W.S.J. (TU Delft Environmental Fluid Mechanics); Uittenbogaard, Rob (Deltares)","","2019","The work presents an experimental investigation into the motion of and hydrodynamic forces along a single flexible stem in regular waves. The experiment covers a large range in relevant non-dimensional parameters: the drag-to-stiffness ratio, the inertia-to-stiffness ratio, the Keulegan-Carpenter number and the Reynolds number. The two first parameters relate to the response of the stem in waves and thus account for material properties, while the two last parameters are relevant for hydrodynamic forces on the stem. The displacement of the stem was captured with a digital video camera and the displacement along the stem was captured for every 2.5 mm at 25 Hz. This unique laboratory data set allowed for the following analyses: (i) Determination of the relevant non-dimensional parameter to predict the stem motion and shape. (ii) A direct comparison between the measured force for mimics of two lengths (0.15 m and 0.30 m) illustrating the force reduction potential for flexible mimics. (iii) Direct evaluation of the average force coefficients (drag) and (inertia) for the flexible stems. (iv) The distributed external hydrodynamic loading and the internal shear forces were estimated from the laboratory experiments. The distribution of the shear force helped to understand the breakage mechanisms of flexible stems. (v) A linkage between phase lags and internal shear forces was suggested. The data set is considered valuable as validation material for numerical models of stem motion in waves.","coastal engineering; wave-structure interactions","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-04-18","","","Environmental Fluid Mechanics","","",""
"uuid:cbb482a0-6443-49a5-aef9-05cafe0f74be","http://resolver.tudelft.nl/uuid:cbb482a0-6443-49a5-aef9-05cafe0f74be","Transparency in Responsible Design: Avoiding Engineering Overconfidence and Supporting Societal Acceptance","Vermaas, P.E. (TU Delft Ethics & Philosophy of Technology)","","2019","In this contribution it is argued that in responsible design engineers should be transparent towards stakeholders about the goals they intend to realise with their designs. The emergence of responsible design in, e.g., value-sensitive design, design for values, social design, nudging and positive design, is to be welcomed. It has however the weakness of overconfidence which may lead engineers to suspend earlier commitments to society as given in engineering codes of conduct and ethics, and practices of seeking informed consent and taking blame. It is argued that these earlier commitments lead to the requirement that engineers should be transparent about the goals in responsible designs. Providing this transparency support moreover the societal acceptance of responsible design since it positions engineers doing responsible design as subscribing to values such as respect, honesty and trust. I illustrate the argument with a case of social design and a case of nudging.","Communication; Engineering codes of conduct; Ethics; Social responsibility; Transparancy","en","conference paper","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:dbf9a46d-e7db-4de8-95c1-9586ed538e40","http://resolver.tudelft.nl/uuid:dbf9a46d-e7db-4de8-95c1-9586ed538e40","Forensic Analysis of Levee Failures: The Breitenhagen Case","Kool, J.J. (TU Delft Hydraulic Structures and Flood Risk); Kanning, W. (TU Delft Hydraulic Structures and Flood Risk); Heyer, Torsten (Technische Universität Dresden); Jommi, C. (TU Delft Geo-engineering); Jonkman, Sebastiaan N. (TU Delft Hydraulic Structures and Flood Risk)","","2019","Forensic analysis of past failures is valuable to improve our understanding of levee behavior. In this article a new systematic approach of forensic analysis for levee failures is proposed and applied to the Breitenhagen levee breach that occurred along the river Saale in Germany in 2013. The purpose of this study is to identify the cause of the breach based on the proposed approach, even though limited data is available. Based on the information prior, during and after the breach of the levee, a slope stability model is developed for the entire event. First, results from this model are obtained based on the expected values of the uncertain parameters and the best estimates of the situation. Uncertainty of the model is included in the calculation subsequently by defining possible failure scenarios. The most likely failure scenarios are derived from the data and included into the model so that it is possible to eliminate or validate all possible causes by means of a sensitivity calculation. It is concluded that the levee breach is likely caused by locally weak soil conditions, unexpected high water pressures due to a connection between a pond and the aquifer and unexpected saturation of the levee. These conditions are associated with the occurrence of a previous breach at this location.","forensic engineering; slope instability; hindcasting; river levee; levee breach","en","journal article","","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:92cdc60b-cd02-48f7-abc0-50d8b72bcd4f","http://resolver.tudelft.nl/uuid:92cdc60b-cd02-48f7-abc0-50d8b72bcd4f","Socio-Cognitive Engineering of a Robotic Partner for Child's Diabetes Self-Management","Neerincx, M.A. (TU Delft Interactive Intelligence; TNO); van Vught, Willeke (TNO); Blanson Henkemans, O.A. (TNO); Oleari, Elettra (Ospedale San Raffaele); Broekens, D.J. (TU Delft Interactive Intelligence); Rijgersberg, R.M. (TU Delft Interactive Intelligence); Kaptein, F.C.A. (TU Delft Interactive Intelligence); Demiris, Yiannis (Imperial College London); Kiefer, Bernd (German Research Centre for Artificial Intelligence (DFKI)); Fumagalli, Diego (Mixel); Bierman, Bert (Produxi)","","2019","Social or humanoid robots do hardly show up in “the wild,” aiming at pervasive and enduring human benefits such as child health. This paper presents a socio-cognitive engineering (SCE) methodology that guides the ongoing research & development for an evolving, longer-lasting human-robot partnership in practice. The SCE methodology has been applied in a large European project to develop a robotic partner that supports the daily diabetes management processes of children, aged between 7 and 14 years (i.e., Personal Assistant for a healthy Lifestyle, PAL). Four partnership functions were identified and worked out (joint objectives, agreements, experience sharing, and feedback & explanation) together with a common knowledge-base and interaction design for child's prolonged disease self-management. In an iterative refinement process of three cycles, these functions, knowledge base and interactions were built, integrated, tested, refined, and extended so that the PAL robot could more and more act as an effective partner for diabetes management. The SCE methodology helped to integrate into the human-agent/robot system: (a) theories, models, and methods from different scientific disciplines, (b) technologies from different fields, (c) varying diabetes management practices, and (d) last but not least, the diverse individual and context-dependent needs of the patients and caregivers. The resulting robotic partner proved to support the children on the three basic needs of the Self-Determination Theory: autonomy, competence, and relatedness. This paper presents the R&D methodology and the human-robot partnership framework for prolonged “blended” care of children with a chronic disease (children could use it up to 6 months; the robot in the hospitals and diabetes camps, and its avatar at home). It represents a new type of human-agent/robot systems with an evolving collective intelligence. The underlying ontology and design rationale can be used as foundation for further developments of long-duration human-robot partnerships “in the wild.”","child-robot interaction; conversational agent; t, human-robot partnership; socio-cognitive engineering; diabetes management; personal health; , pervasive lifestyle support","en","journal article","","","","","","","","","","","Interactive Intelligence","","",""
"uuid:9fc4a63c-57bf-4a80-aca2-48f5a8fb08a3","http://resolver.tudelft.nl/uuid:9fc4a63c-57bf-4a80-aca2-48f5a8fb08a3","Tracing Back Log Data to its Log Statement: From Research to Practice","Schipper, Daan (Adyen B.V.); Aniche, Maurício (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology)","","2019","Logs are widely used as a source of information to understand the activity of computer systems and to monitor their health and stability. However, most log analysis techniques require the link between the log messages in the raw log file and the log statements in the source code that produce them. Several solutions have been proposed to solve this non-trivial challenge, of which the approach based on static analysis reaches the highest accuracy. We, at Adyen, implemented the state-of-the-art research on log parsing in our logging environment and evaluated their accuracy and performance. Our results show that, with some adaptation, the current static analysis techniques are highly efficient and performant. In other words, ready for use.","software engineering; runtime monitoring; log parsing","en","conference paper","IEEE","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:7404c04d-29ea-43d0-b586-1e7f934d95f4","http://resolver.tudelft.nl/uuid:7404c04d-29ea-43d0-b586-1e7f934d95f4","Students as Future Workers: Cross-border Multidisciplinary Learning Labs in Higher Education","Admiraal, Wilfried (Universiteit Leiden); Post, Lysanne (Universiteit Leiden); Guo, Pengyue (Universiteit Leiden); Saab, Nadira (Universiteit Leiden); Makinen, Sari (Haaga-Helia University of Applied Sciences); Rainio, Ohto (Haaga-Helia University of Applied Sciences); Vuori, Johanna (Haaga-Helia University of Applied Sciences); Kortuem, G.W. (TU Delft Internet of Things); Bourgeois, J. (TU Delft Internet of Things); Danford, Gerard (Haaga-Helia University of Applied Sciences)","","2019","One promising way to cope with changing requirements from the labor market in the domain of Science, Technology, Engineering and Mathematics (STEM), but also to keep the field up to date, to start innovations and to advance the STEM domain as such is the use of student labs. In these labs, students work together in small groups imitating professional practice of design and technology workers. More insights are needed in what competences student labs in the STEM domain address and what the implications would be for the design of student labs. A review of empirical studies on student labs and additional literature indicate that five generic competences are addressed in most student labs: Collaboration, communication, problem solving, critical thinking, and creativity. In order to effectively enhanced these competences, student labs should be designed as authentic productive learning environments based on three design principles: 1) Realistic, complex task situations, 2) Multidisciplinarity, and 3) Social interaction. IoT Rapid Proto Labs are examples of such a student labs, in which cross-border multidisciplinary teams of students, teachers (coaches), and practitioners jointly develop solutions to challenging IoT applications (Internet-connected objects), add value for enterprises, and strengthen the employability, creativity and career prospects of students.","Student labs; Authentic learning; Science, Technology, Engineering and Mathematics (STEM); Higher education","en","journal article","","","","","","","","","","","Internet of Things","","",""
"uuid:dd2e521f-22bb-4b77-9167-c8d2ff5abc69","http://resolver.tudelft.nl/uuid:dd2e521f-22bb-4b77-9167-c8d2ff5abc69","Engineered 3D Polymer and Hydrogel Microenvironments for Cell Culture Applications","Fan, D. (TU Delft Micro and Nano Engineering); Staufer, U. (TU Delft Micro and Nano Engineering); Accardo, A. (TU Delft Micro and Nano Engineering)","","2019","The realization of biomimetic microenvironments for cell biology applications such as organ-on-chip, in vitro drug screening, and tissue engineering is one of the most fascinating research areas in the field of bioengineering. The continuous evolution of additive manufacturing techniques provides the tools to engineer these architectures at different scales. Moreover, it is now possible to tailor their biomechanical and topological properties while taking inspiration from the characteristics of the extracellular matrix, the three-dimensional scaffold in which cells proliferate, migrate, and differentiate. In such context, there is therefore a continuous quest for synthetic and nature-derived composite materials that must hold biocompatible, biodegradable, bioactive features and also be compatible with the envisioned fabrication strategy. The structure of the current review is intended to provide to both micro-engineers and cell biologists a comparative overview of the characteristics, advantages, and drawbacks of the major 3D printing techniques, the most promising biomaterials candidates, and the trade-offs that must be considered in order to replicate the properties of natural microenvironments.","3D microenvironment; additive manufacturing; biomaterials; cell culture; tissue engineering; polymer; hydrogel","en","journal article","","","","","","","","","","","Micro and Nano Engineering","","",""
"uuid:aedcd0ea-32ce-4ad4-b641-4133ab1c36f0","http://resolver.tudelft.nl/uuid:aedcd0ea-32ce-4ad4-b641-4133ab1c36f0","Do as i Do, Not as i Say: Do Contribution Guidelines Match the GitHub Contribution Process?","Elazhary, Omar (University of Victoria); Storey, Margaret-Anne (University of Victoria); Ernst, Neil (University of Victoria); Zaidman, A.E. (TU Delft Software Engineering)","","2019","Developer contribution guidelines are used in social coding sites like GitHub to explain and shape the process a project expects contributors to follow. They set standards for all participants and 'save time and hassle caused by improperly created pull requests or issues that have to be rejected and re-submitted' (GitHub). Yet, we lack a systematic understanding of the content of a typical contribution guideline, as well as the extent to which these guidelines are followed in practice. Additionally, understanding how guidelines may impact projects that use Continuous Integration as part of the contribution process is of particular interest. To address this knowledge gap, we conducted a mixed-methods study of 53 GitHub projects with explicit contribution guidelines and coded the guidelines to extract key themes. We then created a process model using GitHub activity data (e.g., commit, new issue, new pull request) to compare the actual activity with the prescribed contribution guidelines. We show that approximately 68% of these projects diverge significantly from the expected process.","automation; code contributions; software engineering","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-07-01","","","Software Engineering","","",""
"uuid:b796b095-cf8b-40c7-92d5-5abfa991e807","http://resolver.tudelft.nl/uuid:b796b095-cf8b-40c7-92d5-5abfa991e807","Search-based multi-vulnerability Testing of XML injections in web applications","Jan, Sadeeq (University of Luxembourg; University of Engineering and Technology, Peshawar); Panichella, A. (TU Delft Software Engineering; University of Luxembourg); Arcuri, Andrea (Kristiania University College); Briand, Lionel (University of Luxembourg)","","2019","Modern web applications often interact with internal web services, which are not directly accessible to users. However, malicious user inputs can be used to exploit security vulnerabilities in web services through the application front-ends. Therefore, testing techniques have been proposed to reveal security flaws in the interactions with back-end web services, e.g., XML Injections (XMLi). Given a potentially malicious message between a web application and web services, search-based techniques have been used to find input data to mislead the web application into sending such a message, possibly compromising the target web service. However, state-of-the-art techniques focus on (search for) one single malicious message at a time. Since, in practice, there can be many different kinds of malicious messages, with only a few of them which can possibly be generated by a given front-end, searching for one single message at a time is ineffective and may not scale. To overcome these limitations, we propose a novel co-evolutionary algorithm (COMIX) that is tailored to our problem and uncover multiple vulnerabilities at the same time. Our experiments show that COMIX outperforms a single-target search approach for XMLi and other multi-target search algorithms originally defined for white-box unit testing.","Code injection vulnerabilities; Search-based software engineering; Security testing","en","journal article","","","","","","","","2020-04-13","","","Software Engineering","","",""
"uuid:93a846b7-0f39-4d28-883b-24b829cadbed","http://resolver.tudelft.nl/uuid:93a846b7-0f39-4d28-883b-24b829cadbed","Evaluation of competency methods in engineering education: A systematic review","Leandro Cruz, M. (TU Delft Novel Aerospace Materials); Saunders-Smits, Gillian (TU Delft Aerospace Structures & Materials); Groen, W.A. (TU Delft Aerospace Structures & Materials)","","2019","The purpose of this systematic review is to evaluate the state-of-the-art of competency measurement methods with an aim to inform the creation of reliable and valid measures of student mastery of competencies in communication, lifelong learning, innovation/creativity and teamwork in engineering education. We identified 99 studies published in three databases over the last 17 years. For each study, purpose, corresponding methods, criteria used to establish competencies, and validity and reliability properties were evaluated. This analysis identified several measurement methods of which questionnaires and rubrics were the most used. Many measurement methods were found to lack competency definitions and evidence of validity and reliability. These show a clear need for establishing professional standards when measuring mastery of competencies. Therefore, in this paper, we propose guidelines for the design of reliable and valid measurement methods to be used by educators and researchers.","Transversal competencies; competency measurement; competency assessment; systematic review; engineering education","en","review","","","","","","","","","","Aerospace Structures & Materials","Novel Aerospace Materials","","",""
"uuid:88bd1e06-b898-4948-aa28-b56d5b8ab60f","http://resolver.tudelft.nl/uuid:88bd1e06-b898-4948-aa28-b56d5b8ab60f","Transversal Competency Level of Engineering Graduates Dictated by European Industry","Leandro Cruz, M. (TU Delft Novel Aerospace Materials); Saunders-Smits, Gillian (TU Delft Aerospace Structures & Materials)","","2019","The importance of which transversal competencies, a collective term for non-technical competencies such as problem-solving and communication skills, are required for student success in the labor market has been studied. There is no doubt that students need transversal competencies for professional practice. However, little is known about the specific competency level that graduates should hold after completion of their Bachelor or Master in Engineering. To investigate graduates’ competency levels, this article reports on the design, development, and results of an industry questionnaire, which studies the perception of industry representatives in Europe of the competency levels that Bachelor and Master engineering graduates should hold after graduation. A total of 28 representatives who work in the engineering industry and who recruit or work with recently graduated engineers responded. Industry representatives were given a list of 36 competencies and were asked to select the most important competencies and the competency level they perceive students should have after completion of their Bachelor and Master degree for each. Significant differences were found between the required competency levels for Bachelor and Master graduates. Industry representatives perceived that Master graduates require mostly advance level (as opposed to a lower level for bachelor graduates) for competencies such as risk tolerance, problem-solving, listening skills, writing skills, interdisciplinary thinking, strengths/weaknesses awareness, and actively seeking learning. These findings were unaffected by years of work experience of the industry respondents or their company size. The findings of this study help higher education institutions, employers and lecturers to stimulate the development of competencies required by industry. More specifically, they will be used as a starting point for developing and implementing curriculum elements aimed at enhancing competency levels of students at a Dutch university of technology and its European partners in the European project funding this research.","Transversal competency level; preparing for practice; engineering education, questionnaire; Preparing for practice; Questionnaire; Engineering education","en","conference paper","","","","","","","","","","Aerospace Structures & Materials","Novel Aerospace Materials","","",""
"uuid:2c43a743-dfcb-41b2-a027-de732df4482b","http://resolver.tudelft.nl/uuid:2c43a743-dfcb-41b2-a027-de732df4482b","An adaptive approach to longitudinal platooning with heterogeneous vehicle saturations","Tao, T. (TU Delft Team Bart De Schutter); Jain, V. (Student TU Delft); Baldi, S. (TU Delft Team Bart De Schutter; Southeast University)","","2019","Adaptive CACC strategies have been recently proposed to stabilize a platoon with non-identical and uncertain vehicle dynamics (heterogeneous platoon). This work proposes a method to augment such strategies with a mechanism coping with saturation constraints (i.e. engine constraints). In fact, in a platoon of heterogeneous vehicles, engine constraints might lead to loss of cohesiveness. The proposed mechanism is based on making the reference dynamics (i.e the dynamics to which the platoon should homogenize) ‘not too demanding’, by applying a properly designed saturation action. Such saturation action will allow all vehicles in the platoon not to hit their engine bounds. Cohesiveness will then be achieved at the price of losing some performance, which is in line with the state of art studies on this topic. Simulations on a platoon of 5 vehicles are conducted to validate the theoretical analysis.","Cooperative adaptive cruise control; engine constraints; heterogeneous platoon; model reference adaptive control","en","journal article","","","","","","","","","","","Team Bart De Schutter","","",""
"uuid:b80e37bc-ac7d-4942-9d76-3b5b78532ced","http://resolver.tudelft.nl/uuid:b80e37bc-ac7d-4942-9d76-3b5b78532ced","Flights are ten a sail - Re-use and commonality in the design and system engineering of small spacecraft solar sail missions with modular hardware for responsive and adaptive exploration","Grundmann, Jan Thimo (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Bauer, Waldemar (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Boden, Ralf (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Ceriotti, Matteo (University of Glasgow); Chand, Suditi (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Heiligers, M.J. (TU Delft Astrodynamics & Space Missions); Vergaaij, Merel (University of Glasgow); Viavattene, Giulia (University of Glasgow); Wolff, Friederike (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR))","","2019","The exploration of small solar system bodies started with fast fly-bys of opportunity on the sidelines of missions to the planets. The tiny new worlds seen turned out to be so intriguing and different from all else (and each other) that dedicated sample-return and in-situ analysis missions were developed and launched. Through these, highly efficient low-thrust propulsion expanded from commercial use into mainstream and flagship science missions, there in combination with gravity assists propulsion. In parallel, the growth of small spacecraft solutions accelerated in numbers as well as individual spacecraft capabilities. The on-going missions OSIRIS-REX (NASA) or HAYABUSA2 (JAXA) with its landers MINERVA-II and MASCOT, and the upcoming NEASCOUT mission are examples of this synergy of trends. The continuation of these and other related devlopments towards a propellant-less and highly efficient class of spacecraft for solar system exploration emerges in the form of small spacecraft solar sails designed for carefree handling and equipped with carried landers and application modules. These address the needs of all asteroid user communities - planetary science, planetary defence, and in-situ resource utilization - as well as other fields of solar system science and applications such as space weather warning and solar observations. Already the DLR-ESTEC GOSSAMER Roadmap for Solar Sailing initiated studies of missions uniquely feasible with solar sails such as Displaced L1 (DL1) space weather advance warning and monitoring and Solar Polar Orbiter (SPO) delivery, which demonstrate the capabilities of near-term solar sails to reach any kind of orbit in the inner solar system. This enables Multiple Near-Earth Asteroid (NEA) rendezvous missions (MNR), from Earth-coorbital to extremely inclined and even retrograde target orbits. For these mission types using separable payloads, design concepts can be derived from the separable Boom Sail Deployment Units characteristic of DLR GOSSAMER solar sail technology, nanolanders like MASCOT, or microlanders like the JAXA-DLR Jupiter Trojan Asteroid Lander for the OKEANOS mission which can shuttle from the sail to the targets visited and enable multiple NEA sample-return missions. These nanospacecraft scale components are an ideal match creating solar sails in micro-spacecraft format whose launch configurations are compatible with secondary payload platforms such as ESPA and ASAP. The DLR GOSSAMER solar sail technology builds on the experience gained in the development of deployable membrane structures leading up to the successful ground deployment test of a (20 m)2 solar sail at DLR Cologne in 1999 and in the 20 years since.","Multiple NEA rendezvous; Responsive space; Small solar system body characterisation; Small spacecraft asteroid lander; Small spacecraft solar sail; System engineering","en","journal article","","","","","","","","","","","Astrodynamics & Space Missions","","",""
"uuid:01c8ad26-467c-4cef-bf69-8d1167eac7bd","http://resolver.tudelft.nl/uuid:01c8ad26-467c-4cef-bf69-8d1167eac7bd","Sustainable delta landscapes need smarter port city regions","Meyer, Han (TU Delft Urban Design)","","2019","Economic and spatial developments of port cities have large impacts on the quality of the natural environment, the safety of people living in the urbanized areas and the fresh water supply for drinking water and agriculture. Creating a proper balance among these different aspects, makes it necessary to provide new concepts and instruments at the regional scale. During the last two centuries, port city development has been defined by the paradigm of the primacy of economic development, which had to be supported and facilitated by engineering and urban planning. Following this paradigm, dynamic and ecologically rich deltas have been transformed into artificial landscapes, resulting in ecological decay, increasing flood risk in urban areas and increasing salinization of surface and groundwater. Because of climate change, these problems in port city regions are increasing exponentially. This paper argues that new approaches should be developed in port city regions, combining ecological repair of delta landscapes by ‘building-with-nature’ methods of hydraulic engineering, with a transition of port city regions related to energy transition and the rise of a circular economy. We need a new paradigm, resulting in an integrated, holistic approach of port city regions, and with governance structures which are able to implement this holistic approach. This paper shows the essence and urgency of this new paradigm, as well as the glimpses of the start of a new approach, illustrated by the developments in two delta regions, which are the home bases of two of the largest port complexes of the world: the Mississippi river delta with the ports of New Orleans, and the Rhine-Meuse-Scheldt delta with Rotterdam and Antwerp. The new paradigm is only possible when the governance system will change at the global, national, regional and local levels.","Dynamic delta landscapes; Port city regions; Building with nature; Design as engine of change","en","journal article","","","","","","Special Issue “Governance in Port City Regions”","","","","","Urban Design","","",""
"uuid:5eb8e7b9-3d61-4c15-8c74-61a1c904d11d","http://resolver.tudelft.nl/uuid:5eb8e7b9-3d61-4c15-8c74-61a1c904d11d","Developing modelling and simulation standards for including the cyber domain in military training and exercises","Boltjes, Bert (TNO); Maathuis, E.C. (TU Delft Information and Communication Technology); van den Berg, Tom (TNO); Gouweleeuw, Rudi (TNO)","","2019","As cyber operations are evolving to become a major military enabler, cyber activities and their resulting effects should also be represented in simulation environments. Currently much effort is being put into creating simulation environments to enable the simulation of cyber operations at the technical (network) level. At this level the focus is on detection and exploitation of vulnerabilities on the offensive side and on prevention, detection and mitigation of malicious intrusions on the defensive side. Simulations at this level facilitate training of and competition between cyber technicians. Typical examples are so-called “Capture-the-flag” events. However, cyber operations also have an important impact at the tactical, operational and strategical level, but so far little effort has been put into integration of cyber operations and their effects at these levels. What there is, is mainly limited to degrading some of the tactical data communication or switching off C2 systems or simulators. A standard approach is required to integrate offensive and defensive cyber activities and their resulting effects in simulation environments in a timely, efficient, interoperable, and cost-effective manner. A first requirement for a standard approach is to describe the elements of systems that can be affected by cyber operations, their characteristics, the way they interact, offensive and defensive cyber activities and the effects they can have on operational capabilities. For this purpose, taxonomies and ontologies for cyber operations have been described in the literature, but they only cover elements of cyber operations (tailored to specific attacks, threats, vulnerabilities et cetera). All these attempts serve a specific research purpose and there is limited or no coherence between them. With only one exception that we know of, the research results have, beside papers, not been available for further development. Open sources and standards are lacking which hinders further development of interoperable products for introducing cyber operations in modelling and simulation for training and experimentation as they do exist for Land, Sea, Air, and Space. An ontology for the cyber domain is – however – important to the development of (re-usable) simulation conceptual models, simulation scenarios and simulation data exchange models. An ontology provides amongst others consistent naming, meaning, relations and interactions of the various elements used in the different models. TNO Defence Research is strongly involved in many standardisation activities for modelling and simulation in the military domain. In addition, as part of a doctoral research project (Technical University Delft, TNO Defence Research, and Netherlands Defence Academy (NLDA)) aimed at assessing the effects of cyber operations in support of targeting decision making that avoids collateral damage. In this context computational ontologies have been developed to describe cyber operations and to represent and reason around the necessary knowledge to assess the effects of cyber operations. These ontologies can be regarded as a (knowledge-based) simulation environment resulting from empirical research and design studies in the military cyber domain. This paper describes a development method, focussed on the construction of a cyber operations ontology for training and exercises, and the initial steps toward a cyber simulation data exchange model.","Computational ontology; Cyber; Cyber domain engineering; Cyber effects; Cyber reference FOM","en","conference paper","Simulation Interoperability Standards Organization","","","","","","","","","","Information and Communication Technology","","",""
"uuid:e4d1fe47-bd79-4c67-ae4c-fd1b102560fe","http://resolver.tudelft.nl/uuid:e4d1fe47-bd79-4c67-ae4c-fd1b102560fe","Identifying ecosystem-based alternatives for the design of a seaports marine infrastructure: The case of tema port expansion in Ghana","de Boer, W.P. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Deltares); Slinger, J (TU Delft Policy Analysis; Rhodes University); wa Kangeri, Arno K. (Wageningen University & Research); Vreugdenhil, H.S.I. (TU Delft Policy Analysis; Deltares); Taneja, P. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Addo, Kwasi Appeaning (University of Ghana); Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)","","2019","Long-term sustainable port development requires accounting for the intrinsic values of ecosystems. However, in practice, ecosystem considerations often only enter the planning and design process of ports when required by an Environmental Impact Assessment. At this late stage, most of the design is already fixed and opportunities to minimize and restore ecosystem impacts are limited. In this paper, we adopt a large-scale, ecosystem perspective on port development with the aim to identify ecosystem-based design alternatives earlier and throughout the planning and design of a port's marine infrastructure. We present a framework, termed the 'ecosystem-based port design hierarchy' (EPDH), to identify ecosystem-based alternatives at four hierarchical design levels: 1) alternatives to port developments, 2) port site selection, 3) port layout design, and 4) design of structures and materials. In applying the EPDH framework retrospectively to a case study of port expansion in Tema, Ghana, we establish that ecosystem considerations played only a limited role in identifying and evaluating alternatives at all four design levels in the case study, whereas more eco-friendly alternatives in terms of port layouts, structures, and materials are identified using the EPDH framework. This reveals that opportunities for ecosystem-friendly port designs may have been missed and demonstrates the need for and the potential added value of our framework. The framework can assist practitioners in earlier and wider identification of ecosystem-based alternatives for a port's marine infrastructure in future seaport developments and, hence, represents an important step towards more sustainable port designs.","Coastal environment; Ecosystem-based management; Environmental impacts; Nature-based engineering; Port design; Sustainable ports","en","journal article","","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:dcdcdbb0-e8b0-4ed8-b6a0-1a95bedccbd5","http://resolver.tudelft.nl/uuid:dcdcdbb0-e8b0-4ed8-b6a0-1a95bedccbd5","Combining unmergeables: A methodological framework for axiomatic fusion of qualitative design theories","Horvath, I. (TU Delft Cyber-Physical Systems)","","2019","The proposed methodological framework concerns axiomatic theory fusion (ATF) of non-additive engineering design theories. ATF includes seven steps: (i) semantic discretization of the composite theories, (ii) deriving epistemological entities by logical/semantic analysis, (iii) establishing and representation of relations among all relevant epistemological entities, (iv) combining the inter-theoretical epistemological entities of the component theories, (v) deriving propositions based on the combined set of epistemological entities, (vi) transcription of the epistemological entities and propositions into a textual/visual theory description, and (vii) validation of the resultant theory in application contexts. The proposed framework makes ATF an effective, content independent methodology for fusing component theories, no matter if they are descriptive, explanatory, predictive or controlling in nature. ATF methodology requires professional comprehension and rigor from the researchers. It is necessary to justify the logical correctness and practical validity of the target theory in the specific application context.","Axiomatic theory fusion; Design theory; Postulates; Propositions; Research methodologies and methods; Systems Engineering (SE)","en","journal article","","","","","","","","","","","Cyber-Physical Systems","","",""
"uuid:054b4a4e-4419-4976-a38d-7662378c0f68","http://resolver.tudelft.nl/uuid:054b4a4e-4419-4976-a38d-7662378c0f68","The Quasi-Equilibrium Longitudinal Profile in Backwater Reaches of the Engineered Alluvial River: A Space-Marching Method","Arkesteijn, L. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Blom, A. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Czapiga, Matthew J. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Chavarrias Borras, V. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Deltares); Labeur, R.J. (TU Delft Environmental Fluid Mechanics)","","2019","An engineered alluvial river (i.e., a fixed-width channel) has constrained planform but is free to adjust channel slope and bed surface texture. These features are subject to controls: the hydrograph, sediment flux, and downstream base level. If the controls are sustained (or change slowly relative to the timescale of channel response), the channel ultimately achieves an equilibrium (or quasi-equilibrium) state. For brevity, we use the term “quasi-equilibrium” as a shorthand for both states. This quasi-equilibrium state is characterized by quasi-static and dynamic components, which define the characteristic timescale at which the dynamics of bed level average out. Although analytical models of quasi-equilibrium channel geometry in quasi-normal flow segments exist, rapid methods for determining the quasi-equilibrium geometry in backwater-dominated segments are still lacking. We show that, irrespective of its dynamics, the bed slope of a backwater or quasi-normal flow segment can be approximated as quasi-static (i.e., the static slope approximation). This approximation enables us to derive a rapid numerical space-marching solution of the quasi-static component for quasi-equilibrium channel geometry in both backwater and quasi-normal flow segments. A space-marching method means that the solution is found by stepping through space without the necessity of computing the transient phase. An additional numerical time stepping model describes the dynamic component of the quasi-equilibrium channel geometry. Tests of the two models against a backwater-Exner model confirm their validity. Our analysis validates previous studies in showing that the flow duration curve determines the quasi-static equilibrium profile, whereas the flow rate sequence governs the dynamic fluctuations.","backwater reach; engineered river; equilibrium channel geometry; modeling; river morphodynamics","en","journal article","","","","","","","","2020-04-23","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:2187c2ee-7966-440b-aad9-1163f837ecf9","http://resolver.tudelft.nl/uuid:2187c2ee-7966-440b-aad9-1163f837ecf9","Alarm compliance in healthcare: Design considerations for actionable alarms (in intensive care units)","Sanz Segura, R. (Universidad de Zaragoza); Manchado Pérez, Eduardo (Universidad de Zaragoza); Ozcan Vieira, E. (TU Delft Design Aesthetics)","","2019","Intensive care units are technologically advanced environments that are designed to safeguard the patient while their vitals are stabilized for further treatment. Audible and visual alarms are part of the healthcare ecology. However, these alarms are so many that clinicians suffer from a syndrome called 'alarm fatigue' and often do not comply with the task alarm is conveying. Measuring compliance with rules in the workspace and determining the success of a system belongs to the field of ergonomics and is based on data collected through task observations and scoring. In this paper, we will explore compliance with critical alarms by not only from their potential success or failure perspective but also from the perspectives of the clinician capacity, needs, and motivations to comply with alarms in critical environments. We will finally, reflect on further possible design strategies to increase compliance in critical care that are beyond following rules per se but through intrinsic motivation.","Audible alarms; Compliance; Decision making; Design engineering; Design practice","en","conference paper","Cambridge University Press","","","","","","","","","","Design Aesthetics","","",""
"uuid:b22f1754-d42a-4016-b631-c51c803f486e","http://resolver.tudelft.nl/uuid:b22f1754-d42a-4016-b631-c51c803f486e","An Empirical Study into the Success of Listed Smart Contracts in Ethereum","Hartel, P.H. (TU Delft Cyber Security; Singapore University of Technology and Design); Homoliak, I. (Singapore University of Technology and Design; Brno University of Technology); Reijsbergen, Daniël (Singapore University of Technology and Design)","","2019","Since it takes time and effort to put a new product or service on the market, one would like to predict whether it will be a success. In general this is not possible, but it is possible to follow best practices in order to maximize the chance of success. A smart contract is intended to encode business logic and is therefore at the heart of every new business on the Ethereum blockchain. We have investigated how to measure the success of smart contracts, and whether successful smart contracts have characteristics that less successful smart contracts lack. The appearance of a smart contract on a listing website such as Etherscan or StateoftheDapps is such a characteristic. In this paper, we present a three-pronged analysis of the relative success of listed smart contracts. First, we have used statistical analysis on the publicly visible transaction history of the Ethereum blockchain to determine that listed contracts are significantly more successful than their unlisted counterparts. Next, we have conducted a survey among more than 200 developers via an anonymous online survey about their experience with the listing process. A significant majority of respondents do not believe that listing a contract itself contributes to its success, but they believe that the extra attention that is typically paid in tandem with the listing process does contribute. Finally, based on the respondents' answers, we have drafted 10 recommendations for developers and validated them by submitting them to an international panel of experts.","blockchain; business success; computers and information processing; ethereum; new product development; product development; recommendations for developers; smart contracts; social implications of technology; Software engineering; technology social factors","en","journal article","","","","","","","","","","","Cyber Security","","",""
"uuid:0f765890-43f9-4117-ad97-1e44b9cc0f40","http://resolver.tudelft.nl/uuid:0f765890-43f9-4117-ad97-1e44b9cc0f40","Large Tunability of Strain in WO3 Single-Crystal Microresonators Controlled by Exposure to H2 Gas","Manca, N. (TU Delft QN/Caviglia Lab; Kavli institute of nanoscience Delft; University of Genova; CNR-SPIN Genova); Mattoni, G. (TU Delft QN/Caviglia Lab; Kavli institute of nanoscience Delft); Pelassa, Marco (University of Genova); Venstra, W.J. (TU Delft QN/Afdelingsbureau; Kavli institute of nanoscience Delft; Quantified Air BV); van der Zant, H.S.J. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft); Caviglia, A. (TU Delft QN/Caviglia Lab; Kavli institute of nanoscience Delft)","","2019","Strain engineering is one of the most effective approaches to manipulate the physical state of materials, control their electronic properties, and enable crucial functionalities. Because of their rich phase diagrams arising from competing ground states, quantum materials are an ideal playground for on-demand material control and can be used to develop emergent technologies, such as adaptive electronics or neuromorphic computing. It was recently suggested that complex oxides could bring unprecedented functionalities to the field of nanomechanics, but the possibility of precisely controlling the stress state of materials is so far lacking. Here, we demonstrate the wide and reversible manipulation of the stress state of single-crystal WO3 by strain engineering controlled by catalytic hydrogenation. Progressive incorporation of hydrogen in freestanding ultrathin structures determines large variations of their mechanical resonance frequencies, inducing static deformation. Our results demonstrate hydrogen doping as a new paradigm to reversibly manipulate the mechanical properties of nanodevices based on materials control.","chemical strain; hydrogen doping; microelectromechanical systems; oxide MEMS; strain engineering; transition metal oxides; tungsten trioxide","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-04-30","","","QN/Caviglia Lab","","",""
"uuid:058e48b7-3c40-4cd4-baf1-7fef19cfedef","http://resolver.tudelft.nl/uuid:058e48b7-3c40-4cd4-baf1-7fef19cfedef","Towards optimisation of geothermal heat recovery: An example from the West Netherlands Basin","Willems, C. J.L. (University of Glasgow); Nick, H.M. (TU Delft Reservoir Engineering; Technical University of Denmark)","","2019","The Netherlands experienced the fastest European expansion of geothermal energy exploitation in the past decade. The first Dutch geothermal sites proved that Hot Sedimentary Aquifers exploitation can play an important role in a future low-carbon energy mix. In this study, we estimate that with the expansion rate of the past four years, geothermal heat production from Lower Cretaceous Hot Sedimentary Aquifers could cover up to 20% of the heat demand in the province of Zuid-Holland by 2050. Although this is a significant amount, we show in this study that only 1% of the potentially recoverable heat will be recovered by 2050. This is because of inefficient doublet deployment on a ‘first-come, first served’ basis with operational parameters that focus on objectives of small decentralised heat grid demands. Instead, similar to the common-practise approach in the hydrocarbon industry, a regional coordinated ‘masterplan’ approach could be used to increase heat recovery. Utilising numerical simulations for flow and heat transfer in the subsurface, we showed that the heat recovery efficiency could be increased by tens of percentages with such coordinated doublet deployment. Based on calculations of the Levelized Costs Of Heat for both deployment strategies, we also show that current financial support schemes do not favour heat recovery optimisation. This study emphasises that although Hot Sedimentary Aquifer resources have the potential to cover a significant part of our energy demand, a radical change in financial support schemes and legislation are required to unlock their true potential.","Direct-use; Geothermal field-development; Hot Sedimentary Aquifers; Low-carbon heat; Low-enthalpy; Recovery factor; Reservoir engineering","en","journal article","","","","","","","","","","","Reservoir Engineering","","",""
"uuid:4ec52f19-3b24-44f0-9d85-e9497c7004aa","http://resolver.tudelft.nl/uuid:4ec52f19-3b24-44f0-9d85-e9497c7004aa","Toward developing a yeast cell factory for the production of prenylated flavonoids","Levisson, Mark (Wageningen University & Research); Araya-Cloutier, Carla (Wageningen University & Research); De Bruijn, Wouter J.C. (Wageningen University & Research); Van Der Heide, Menno (Wageningen University & Research); Salvador López, José Manuel (Wageningen University & Research); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Vincken, Jean Paul (Wageningen University & Research); Beekwilder, Jules (Wageningen University & Research)","","2019","Prenylated flavonoids possess a wide variety of biological activities, including estrogenic, antioxidant, antimicrobial, and anticancer activities. Hence, they have potential applications in food products, medicines, or supplements with health-promoting activities. However, the low abundance of prenylated flavonoids in nature is limiting their exploitation. Therefore, we investigated the prospect of producing prenylated flavonoids in the yeast Saccharomyces cerevisiae. As a proof of concept, we focused on the production of the potent phytoestrogen 8-prenylnaringenin. Introduction of the flavonoid prenyltransferase SfFPT from Sophora flavescens in naringenin-producing yeast strains resulted in de novo production of 8-prenylnaringenin. We generated several strains with increased production of the intermediate precursor naringenin, which finally resulted in a production of 0.12 mg L -1 (0.35 μM) 8-prenylnaringenin under shake flask conditions. A number of bottlenecks in prenylated flavonoid production were identified and are discussed.","8-prenylnaringenin; de novo; metabolic engineering; naringenin; prenylated flavonoids; Saccharomyces cerevisiae","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:4ba433d3-d245-43ca-ab13-b05a71542163","http://resolver.tudelft.nl/uuid:4ba433d3-d245-43ca-ab13-b05a71542163","Past, Present and Future of Behaviourally Adaptive Engineered Systems","Horvath, I. (TU Delft Cyber-Physical Systems); Suárez Rivero, José Pablo (University of Las Palmas de Gran Canaria); Hernández Castellano, Pedro Manuel (University of Las Palmas de Gran Canaria)","","2019","","adaptive systems; behavioural adaptation; enabling resources; Engineering systems; self-adaptation","en","review","","","","","","Extended editorial Accepted Author Manuscript","","","","","Cyber-Physical Systems","","",""
"uuid:a9269d54-e8b3-4336-ac99-fb4b4cb933ba","http://resolver.tudelft.nl/uuid:a9269d54-e8b3-4336-ac99-fb4b4cb933ba","Fabrication and Design of Wood-Based High-Performance Composites","Frey, Marion (ETH Zürich; Swiss Federal Laboratories for Materials Science and Technology (Empa)); Zirkelbach, Meri (Lucerne University of Applied Sciences and Arts); Dransfeld, C.A. (TU Delft Aerospace Manufacturing Technologies); Faude, Eric (ETH Zürich); Trachsel, Etienne (ETH Zürich); Hannus, Mikael (Stora Enso Oyj); Burgert, Ingo (ETH Zürich; Swiss Federal Laboratories for Materials Science and Technology (Empa)); Keplinger, Tobias (ETH Zürich; Swiss Federal Laboratories for Materials Science and Technology (Empa))","","2019","Delignified densified wood is a new promising and sustainable material that possesses the potential to replace synthetic materials, such as glass fiber reinforced composites, due to its excellent mechanical properties. Delignified wood, however, is rather fragile in a wet state, which makes handling and shaping challenging. Here we present two fabrication processes, closed-mold densification and vacuum densification, to produce high-performance cellulose composites based on delignified wood, including an assessment of their advantages and limitations. Further, we suggest strategies for how the composites can be re-used or decomposed at the end-of-life cycle. Closed-mold densification has the advantage that no elaborate lab equipment is needed. Simple screw clamps or a press can be used for densification. We recommend this method for small parts with simple geometries and large radii of curvature. Vacuum densification in an open-mold process is suitable for larger objects and complex geometries, including small radii of curvature. Compared to the closed-mold process, the open-mold vacuum approach only needs the manufacture of a single mold cavity.","Bio-based; Cellulose scaffold; Delignified densified wood; Design; Engineering; Issue 153; Natural fiber composite; Recyclable; Vacuum forming; Wet shaping","en","journal article","","","","","","","","","","","Aerospace Manufacturing Technologies","","",""
"uuid:e3c7086f-1800-493b-b9de-4c3f15a4b1db","http://resolver.tudelft.nl/uuid:e3c7086f-1800-493b-b9de-4c3f15a4b1db","Maintaining Tropical Beaches with Seagrass and Algae: A Promising Alternative to Engineering Solutions","James, Rebecca K. (Universiteit Utrecht); Pietrzak, J.D. (TU Delft Environmental Fluid Mechanics); Candy, A.S. (TU Delft Environmental Fluid Mechanics); Katsman, C.A. (TU Delft Environmental Fluid Mechanics); van der Boog, C.G. (TU Delft Environmental Fluid Mechanics); Riva, R.E.M. (TU Delft Physical and Space Geodesy); Slobbe, D.C. (TU Delft Physical and Space Geodesy); Klees, R. (TU Delft Physical and Space Geodesy)","","2019","Tropical beaches provide coastal flood protection, income from tourism, and habitat for flagship species. They urgently need protection from erosion, which is being exacerbated by changing climate and coastal development. Traditional coastal engineering solutions are expensive, provide unstable temporary solutions, and often disrupt natural sediment transport. Instead, natural foreshore stabilization and nourishment may provide a sustainable and resilient long-term solution. Field flume and ecosystem process measurements, along with data from the literature, show that sediment stabilization by seagrass in combination with sediment-producing calcifying algae in the foreshore form an effective mechanism for maintaining tropical beaches worldwide. The long-term efficacy of this type of nature-based beach management is shown at a large scale by comparing vegetated and unvegetated coastal profiles. We argue that preserving and restoring vegetated beach foreshore ecosystems offers a viable, self-sustaining alternative to traditional engineering solutions, increasing the resilience of coastal areas to climate change.","coastal erosion; coastal management; coastal protection; ecosystem services; nature-based engineering","en","journal article","","","","","","","","2020-02-01","","","Environmental Fluid Mechanics","","",""
"uuid:a3603e0f-8d87-4735-9876-50cc7aebf1f8","http://resolver.tudelft.nl/uuid:a3603e0f-8d87-4735-9876-50cc7aebf1f8","A Systematic Comparison of Search Algorithms for Topic Modelling—A Study on Duplicate Bug Report Identification","Panichella, A. (TU Delft Software Engineering)","Nejati, Shiva (editor); Gay, Gregory (editor)","2019","Latent Dirichlet Allocation (LDA) has been used to support many software engineering tasks. Previous studies showed that default settings lead to sub-optimal topic modeling with a dramatic impact on the performance of such approaches in terms of precision and recall. For this reason, researchers used search algorithms (e.g., genetic algorithms) to automatically configure topic models in an unsupervised fashion. While previous work showed the ability of individual search algorithms in finding near-optimal configurations, it is not clear to what extent the choice of the meta-heuristic matters for SE tasks. In this paper, we present a systematic comparison of five different meta-heuristics to configure LDA in the context of duplicate bug reports identification. The results show that (1) no master algorithm outperforms the others for all software projects, (2) random search and PSO are the least effective meta-heuristics. Finally, the running time strongly depends on the computational complexity of LDA while the internal complexity of the search algorithms plays a negligible role.","Duplicate Bug Report; Evolutionary Algorithms; Latent Dirichlet Allocation; Search-based Software Engineering; Topic modeling","en","conference paper","Springer","","","","","","","","","","Software Engineering","","",""
"uuid:49ea0f83-bd25-46aa-8095-2ffc659e7b0d","http://resolver.tudelft.nl/uuid:49ea0f83-bd25-46aa-8095-2ffc659e7b0d","Increasing the load capacity of planar ferrofluid bearings by the addition of ferromagnetic material","Boots, A. S.T. (Student TU Delft); Krijgsman, L. E. (Student TU Delft); de Ruiter, B. J.M. (Student TU Delft); Lampaert, S.G.E. (TU Delft Mechatronic Systems Design); Spronck, J.W. (TU Delft Mechatronic Systems Design)","","2019","Ferrofluid pocket bearings are a type of bearing that are able to carry a load using an air pocket encapsulated by a ferrofluid seal. Previously designed ferrofluid bearings show the great potential of the stick-slip-free and low viscous friction bearings, however until now the load capacity is limited. In this article a method is presented to increase the load capacity in a simple and cost effective way by the addition of ferromagnetic material around the magnet. First, a mathematical model of the bearing is presented and is validated by experiments using an axially magnetized ring magnet surrounded by two steel rings. The model is used to optimize the dimensions of the added ferromagnetic material for maximum load capacity. Depending on the fly height, the load capacity has been increased by a factor three to four by the addition of steel rings to the ferrofluid pocket bearing configuration.","Hydrostatic bearing; Magnetics; Mathematical modelling; Optimization; Precision engineering","en","journal article","","","","","","","","","","","Mechatronic Systems Design","","",""
"uuid:b303a253-3e41-49bf-9029-91fcd9a51236","http://resolver.tudelft.nl/uuid:b303a253-3e41-49bf-9029-91fcd9a51236","Modeling the electrochemical conversion of carbon dioxide to formic acid or formate at elevated pressures","Morrison, A.R.T. (TU Delft Large Scale Energy Storage); van Beusekom, Vincent (Student TU Delft); Ramdin, M. (TU Delft Engineering Thermodynamics); van den Broeke, L.J.P. (TU Delft Engineering Thermodynamics); Vlugt, T.J.H. (TU Delft Engineering Thermodynamics); de Jong, W. (TU Delft Large Scale Energy Storage)","","2019","In this work a model of an elevated pressure CO2 electrolyzer producing primarily formate or formic acid is presented. It consists of three parts: A model of the bulk electrolyte, the diffusion layer, and the electrode surface. Data from the literature was used to validate both the bulk portion of the model, as well as the overall model. Results from the literature were further explored and explained by reference to the model and faradaic efficiency is predicted very well (R-Square of 0.99 for the fitted data, and 0.98 for the non-fitted data). The primary effect of increasing the pressure on a CO2 electrolyzer is seen to be increasing the maximum attainable partial current density, while the faradaic efficiency and specific energy of formation plateau at pressures above 10-20 bar, at 95% and of 3.7 kWh/kg, respectively. Unlike the efficiencies, the profitability of running a reactor increases with pressure, following a similar trend as partial current density, showing the importance of this quantity as a performance metric of a CO2 electrolyzer. In general this work shows the utility of a model of this sort in the design, evaluation and operation of CO2 electrolyzers.","Electrochemical Engineering; Energy Conversion; Industrial Electrolysis; CO2 electroreduction; High Pressure Electrolyzer; Simulation","en","journal article","","","","","","","","","","","Large Scale Energy Storage","","",""
"uuid:74600a91-e647-4249-8c9f-042c5543f2e5","http://resolver.tudelft.nl/uuid:74600a91-e647-4249-8c9f-042c5543f2e5","Dynamic response of an offshore structure interacting with an ice floe failing in crushing","Hendrikse, H. (TU Delft Hydraulic Engineering; TU Delft Offshore Engineering; Norwegian University of Science and Technology (NTNU)); Nord, Torodd S. (Norwegian University of Science and Technology (NTNU))","","2019","Interaction of sea or lake ice with vertically sided offshore structures may result in severe structural vibrations commonly referred to as ice-induced vibrations. With the surge in offshore wind developments in sub-arctic regions this problem has received increased attention over the last decade, whereas traditionally the topic has been mainly associated with lighthouses and structures for hydrocarbon extraction. It is important for the safe design of these offshore structures to have the ability to predict the interaction between ice and structure in an expected scenario. A model for simulation of the interaction between a drifting ice floe and a vertically sided offshore structure is presented. The nonlinear speed dependent ductile and brittle deformation and local crushing of ice are considered phenomenologically. A one-dimensional sea ice dynamics model is applied to incorporate the effects of floe size, wind and current. The structure is modelled by incorporating its modal properties obtained from a general-purpose finite element software package. Alternatively, the model can be coupled to in-house design software for fully coupled simulations. Examples of application of the model to simulate dynamic ice-structure interaction are provided. Simulation results are validated with public data from forced vibration experiments, small-scale intermittent crushing and frequency lock-in, and full-scale interaction with the Norströmsgrund lighthouse. Effects of floe size and environmental driving forces on the development of ice-induced vibrations in full-scale are studied. It is shown that sustained frequency lock-in vibrations of the structure can only develop for very specific combinations of environmental driving forces and ice floe size. In all other cases, the ice floe slows down and comes to a stop, or accelerates to a drift speed which exceeds the range where frequency lock-in develops. This results in only a few cycles of vibration per interaction event, such as observed for the Norströmsgrund lighthouse in the Baltic Sea.","Continuous brittle crushing; Frequency lock-in; Ice engineering; Ice-induced vibrations; Intermittent crushing","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-08-09","","Hydraulic Engineering","Offshore Engineering","","",""
"uuid:20df38e2-9534-4b25-90b4-315ab1a8197d","http://resolver.tudelft.nl/uuid:20df38e2-9534-4b25-90b4-315ab1a8197d","Applying aluminum-organic matter precipitates to reduce soil permeability in-situ: A field and modeling study","Zhou, Jianchao (TU Delft Geo-engineering); Laumann, S.J. (TU Delft Geo-engineering; Tauw); Heimovaara, T.J. (TU Delft Geoscience and Engineering)","","2019","Using naturally occurring processes to modify the engineering properties of the subsurface has received increasing attention from industry and research communities as they aid in the development of cost-effective, robust and sustainable engineering technologies. In line with this trend, we propose to use precipitates of aluminum (Al) and organic matter (OM) to reduce soil permeability in-situ. This process is inspired by podzolization: a soil stratification process where a layer with low permeability is developed at depth via the precipitation of metal-OM complexes. In this study, the concept of applying Al-OM precipitates for in-situ soil permeability reduction was for the first time applied in the field. The aim of the field experiment was to create a cylindrical flow barrier in a sand layer at depth. In order to design and engineer the field application, we performed a series of scenario analyses with a site-specific 3D reactive transport model. This led to an in-situ engineering approach where a flow barrier was created by separate injection of Al and OM using a combined injection/extraction strategy. During the field application, the local variation of soil conditions required significant modifications to the design. Further scenario analyses with the model were conducted to adapt the original design and to understand the consequences of these modifications. The results show that a cylindrical flow barrier was created after an injection period of 8 days. The precipitation of Al-OM is a highly localized process, where large amount of precipitates is formed in the close vicinity of the injection filter screens. Evaluation of pumping tests that were performed after the injection activities revealed that the permeability of the treated sand was reduced to 2% of its original value. This first full-scale field test demonstrates that applying Al-OM precipitates is a suitable bio-based engineering tool to reduce soil permeability in-situ.","Bio-based engineering; Flow barrier; In-situ permeability reduction; Metal-organic matter complexation; Reactive transport modeling","en","journal article","","","","","","","","","","Geoscience and Engineering","Geo-engineering","","",""
"uuid:740fd430-d6d2-412a-a857-6858352214e2","http://resolver.tudelft.nl/uuid:740fd430-d6d2-412a-a857-6858352214e2","Engineering the direct deposition of Si nanoparticles for improved performance in Li-ion batteries","Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Borsa, Dana M. (Meyer Burger (Netherlands)); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2019","In our efforts to address the issues of Si based anodes for Li ion batteries, such as limited active mass loading, rapid capacity degradation and low scalability in manufacturing, we reported a scalable, high mass loading, and additive-free Si nanoparticles (NP) deposition based electrode, but the achieved capacity and cycle life were still limited. In order to improve the reversible capacity and cycling stability of this Si NP deposition electrode, in this work, we have investigated various substrates for Si deposition, including carbon paper (CP), preheated CP and stainless steel felt/mesh (SSF/SSM), and their influences on the electrochemical Li-ion storage performance of the Si NP electrodes. Meanwhile, protective encapsulations of amorphous carbon or silicon nitride on Si NP has been performed and the capabilities of these coatings in improving the cycling stability of Si NP electrodes have been researched. It is found that a carbon-coated Si NP deposition on an SSM substrate achieves an extraordinary cycling stability in electrochemical Li-ion storage for 500 cycles with an average capacity loss of 0.09% per cycle, showing significantly improved commercial viability of Si NP deposition based electrodes in high-energy-density Li-ion batteries.","Batteries - Lithium; Energy Storage; Silicon; Electrode engineering; Lithium-ion batteries; Silicon nanoparticles deposition","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:691980a6-c288-433e-9091-f84dac2b6d96","http://resolver.tudelft.nl/uuid:691980a6-c288-433e-9091-f84dac2b6d96","Designing thermally stimulated 1.06 mu m Nd3+ emission for the second bio-imaging window demonstrated by energy transfer from Bi3+ in La-, Gd-, Y-, and LuPO4","Lyu, T. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2019","We report a general methodology to the rational design of thermally stimulated short-wave infrared (SWIR) luminescence between ∼900 and 1700 nm by a new combination of using efficient energy transfer from Bi 3+ to Nd 3+ and an adjustable hole trap depth via valence band engineering. Predictions from a vacuum referred binding energy (VRBE) diagram are combined with the data from optical spectroscopy and thermoluminescence to show the design concept by using bismuth and lanthanide doped rare earth ortho-phosphates as model examples. Nd 3+ with its characteristic 4 F 3/2 → 4 I j (j = 9/2, 11/2, 13/2) emission in the SWIR range is first selected as the emitting centre. The energy transfer (ET) processes from Bi 3+ or Tb 3+ recombination centres to Nd 3+ are then discussed. Photoluminescence results show that the energy transfer efficiency of Bi 3+ → Nd 3+ appears to be much higher than of Tb 3+ → Nd 3+ . To exploit this ET, thermally stimulated Bi 3+ A-band emission can then be designed by using Bi 3+ as a ∼2.7 eV deep electron trap in YPO 4 . By combining Bi 3+ with Tb 3+ , Pr 3+ , or Bi 3+ itself, the holes trapped at Tb 4+ , Pr 4+ , or Bi 4+ will release earlier than the electrons captured at Bi 2+ . On recombination with Bi 2+ , Bi 3+ in its excited state is formed generating Bi 3+ A-band emission. Due to the ET of Bi 3+ → Nd 3+ 1.06 μm Nd 3+ emission appears in YPO 4 . Herein, the thermally stimulated Nd 3+ SWIR emission is achieved by hole release rather than the more commonly reported electron release. The temperature when thermally stimulated Nd 3+ SWIR emission appears can further be engineered by changing the Tb 3+ or Pr 3+ hole trap depth in Y 1−x Lu x PO 4 by adjusting x. Such valence band engineering approach can also be applied to other compounds like La 1−x Gd x PO 4 and Gd 1−x La x AlO 3 solid solutions. Our work opens the avenue to motivate scientists to explore novel SWIR afterglow phosphors in a design way instead of by trial and error approach.","Afterglow; Bismuth; Energy transfer; Hole release; Valence band engineering","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:0e97ceea-d37c-4e85-93ef-20ae0ef9931c","http://resolver.tudelft.nl/uuid:0e97ceea-d37c-4e85-93ef-20ae0ef9931c","Mechanical characterization of a unidirectional pultruded composite lamina using micromechanics and numerical homogenization","Xin, H. (TU Delft Steel & Composite Structures; Tongji University); Mosallam, Ayman (University of California); Liu, Yuqing (Tongji University); Veljkovic, M. (TU Delft Steel & Composite Structures); He, Jun (Changsha University of Science and Technology)","","2019","In this paper, analytical and numerical homogenization methods are proposed to effectively simulate the macroscopic characteristics of a pultruded composite lamina. A continuum damage model was implemented via user material subroutine to model fiber failure, while the Mohr-Coulomb plastic criterion is employed to model matrix damage. In order to simulate the damage of the fiber-matrix interface, the relationship between traction and displacement is established. The proposed theoretical and numerical models were verified by tensile, compressive, and shear test results. The outcomes of this study indicated that both theoretical, numerical prediction values agree well with experimental verification results confirming the validity of the proposed methodology in providing a reliable reference for structural design of pultruded fiber reinforced polymeric (FRP) composite structures.","Engineering constants; Micro-mechanic analysis; Mohr-Coulomb plastic criterion; Numerical homogenization; Pultruded unidirectional GFRP lamina","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-11-06","","","Steel & Composite Structures","","",""
"uuid:905c7c21-d772-48cb-878c-901027d910de","http://resolver.tudelft.nl/uuid:905c7c21-d772-48cb-878c-901027d910de","Distant non-obvious mutations influence the activity of a hyperthermophilic Pyrococcus furiosus phosphoglucose isomerase","Subramanian, Kalyanasundaram (Wageningen University & Research); Mitusińska, Karolina (Silesian University of Technology); Raedts, John (Wageningen University & Research); Almourfi, Feras (National Center of Genome Technology, King Abdulaziz City); Joosten, Henk Jan (Bio-Prodict, Nijmegen); Hendriks, Sjon (Wageningen University & Research); Sedelnikova, Svetlana E. (University of Sheffield); Kengen, Servé W.M. (Wageningen University & Research); Hagen, W.R. (TU Delft BT/Biocatalysis)","","2019","The cupin-type phosphoglucose isomerase (PfPGI) from the hyperthermophilic archaeon Pyrococcus furiosus catalyzes the reversible isomerization of glucose-6-phosphate to fructose-6-phosphate. We investigated PfPGI using protein-engineering bioinformatics tools to select functionally-important residues based on correlated mutation analyses. A pair of amino acids in the periphery of PfPGI was found to be the dominant co-evolving mutation. The position of these selected residues was found to be non-obvious to conventional protein engineering methods. We designed a small smart library of variants by substituting the co-evolved pair and screened their biochemical activity, which revealed their functional relevance. Four mutants were further selected from the library for purification, measurement of their specific activity, crystal structure determination, and metal cofactor coordination analysis. Though the mutant structures and metal cofactor coordination were strikingly similar, variations in their activity correlated with their fine-tuned dynamics and solvent access regulation. Alternative, small smart libraries for enzyme optimization are suggested by our approach, which is able to identify non-obvious yet beneficial mutations.","Comulator; Cupin phosphoglucose isomerase; Protein engineering; Pyrococcus furiosus; Solvent access","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:80870370-1dd0-4b5b-ba37-75b328189b26","http://resolver.tudelft.nl/uuid:80870370-1dd0-4b5b-ba37-75b328189b26","HRO and RE: A pragmatic perspective","Haavik, Torgeir K. (Norwegian University of Science and Technology (NTNU)); Antonsen, Stian (SINTEF Technology and Society); Rosness, Ragnar (SINTEF Technology and Society); Hale, A.R. (TU Delft Safety and Security Science; HASTAM)","","2019","This special issue invites to a debate to elaborate on differences and similarities between the perspectives of High Reliability Organisation (HRO) and Resilience Engineering (RE). Such a debate may be conducted along both essentialistic and pragmatic lines, and we suggest that the latter approach is potentially more interesting and fruitful than the first. We use the technique of feeding off controversies and expand on what might at first look merely like a polemic disagreement, a question of wording, namely the definition of safety as a dynamic non-event. This elaboration is used as a projector onto a canvas where a number of distinguishing themes between HRO and RE are outlined more clearly; symmetry, normativity, addressee and origin are keywords that show how HRO and RE are different, and why they cannot simply be combined into one grand theory of everything. Other concrete results from these investigations include a review of applications of HRO and RE in health research, an elaboration of the distinction between Safety I and Safety II, and a nuancing of how we may understand and study successful operations. We suggest a research agenda that combines the scopes and methods of HRO and RE, possibly in combination with other theoretical approaches. We also call for a more lively discussion on central themes of HRO and RE, not for fighting over definitions and proving who is right, but with the aim of producing knowledge that makes a difference regardless of theoretical stance.","Controversies; Dynamic events; Dynamic non-events; High Reliability Organisation (HRO); Pragmatism; Resilience Engineering (RE)","en","journal article","","","","","","","","","","","Safety and Security Science","","",""
"uuid:3cd67344-4539-4463-b4cf-2a5b5410b65f","http://resolver.tudelft.nl/uuid:3cd67344-4539-4463-b4cf-2a5b5410b65f","Modelling and evaluation of PEM hydrogen technologies for frequency ancillary services in future multi-energy sustainable power systems","Alshehri, Feras (Student TU Delft); Garcia Suarez, V. (TU Delft Intelligent Electrical Power Grids); Rueda, José L. (TU Delft Intelligent Electrical Power Grids); Perilla Guerra, A.D. (TU Delft Intelligent Electrical Power Grids); van der Meijden, M.A.M.M. (TU Delft Intelligent Electrical Power Grids; TenneT TSO B.V.)","","2019","This paper examines the prospect of PEM (Proton Exchange Membrane) electrolyzers and fuel cells to partake in European electrical ancillary services markets. First, the current framework of ancillary services is reviewed and discussed, emphasizing the ongoing European harmonization plans for future frequency balancing markets. Next, the technical characteristics of PEM hydrogen technologies and their potential uses within the electrical power system are discussed to evaluate their adequacy to the requirements of ancillary services markets. Last, a case study based on a realistic representation of the transmission grid in the north of the Netherlands for the year 2030 is presented. The main goal of this case study is to ascertain the effectiveness of PEM electrolyzers and fuel cells for the provision of primary frequency reserves. Dynamic generic models suitable for grid simulations are developed for both technologies, including the required controllers to enable participation in ancillary services markets. The obtained results show that PEM hydrogen technologies can improve the frequency response when compared to the procurement with synchronous generators of the same reserve value. Moreover, the fast dynamics of PEM electrolyzers and fuel cells can help mitigate the negative effects attributed to the reduction of inertia in the system.","Electrical engineering","en","journal article","","","","","","","","","","","Intelligent Electrical Power Grids","","",""
"uuid:a9d0a01d-3147-4632-b6cd-892f8ede1033","http://resolver.tudelft.nl/uuid:a9d0a01d-3147-4632-b6cd-892f8ede1033","Sulfate-reducing bacteria that produce exopolymers thrive in the calcifying zone of a hypersaline cyanobacterial mat","Spring, Stefan (Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures); Sorokin, Dimitry Y. (TU Delft BT/Environmental Biotechnology; Winogradsky Institute of Microbiology); Verbarg, Susanne (Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures); Rohde, Manfred (Helmholtz Centre for Infection Research (HZI)); Woyke, Tanja (Joint Genome Institute); Kyrpides, Nikos C. (Joint Genome Institute)","","2019","Calcifying microbial mats in hypersaline environments are important model systems for the study of the earliest ecosystems on Earth that started to appear more than three billion years ago and have been preserved in the fossil record as laminated lithified structures known as stromatolites. It is believed that sulfate-reducing bacteria play a pivotal role in the lithification process by increasing the saturation index of calcium minerals within the mat. Strain L21-Syr-ABT was isolated from anoxic samples of a several centimeters-thick microbialite-forming cyanobacterial mat of a hypersaline lake on the Kiritimati Atoll (Kiribati, Central Pacific). The novel isolate was assigned to the family Desulfovibrionaceae within the Deltaproteobacteria. Available 16S rRNA-based population surveys obtained from discrete layers of the mat indicate that the occurrence of a species-level clade represented by strain L21-Syr-ABT is restricted to a specific layer of the suboxic zone, which is characterized by the presence of aragonitic spherulites. To elucidate a possible function of this sulfate-reducing bacterium in the mineral formation within the mat a comprehensive phenotypic characterization was combined with the results of a comparative genome analysis. Among the determined traits of strain L21-Syr-ABT, several features were identified that could play a role in the precipitation of calcium carbonate: (i) the potential deacetylation of polysaccharides and consumption of substrates such as lactate and sulfate could mobilize free calcium; (ii) under conditions that favor the utilization of formate and hydrogen, the alkalinity engine within the mat is stimulated, thereby increasing the availability of carbonate; (iii) the production of extracellular polysaccharides could provide nucleation sites for calcium mineralization. In addition, our data suggest the proposal of the novel species and genus Desulfohalovibrio reitneri represented by the type strain L21-Syr-ABT (=DSM 26903T = JCM 18662T).","Alkalinity engine; Biofilm; Lithification; Stromatolites; Sulfate reduction","en","journal article","","","","","","","","","","","BT/Environmental Biotechnology","","",""
"uuid:e8d20dc4-5539-42fc-bb47-28345872fd1b","http://resolver.tudelft.nl/uuid:e8d20dc4-5539-42fc-bb47-28345872fd1b","Biological parts for Kluyveromyces marxianus synthetic biology","Rajkumar, Arun S. (University College Cork); Varela, Javier A. (University College Cork); Jürgens, H. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Morrissey, John P.","","2019","Kluyveromyces marxianus is a non-conventional yeast whose physiology and metabolism lends itself to diverse biotechnological applications. While the wild-type yeast is already in use for producing fragrances and fermented products, the lack of standardised tools for its genetic and metabolic engineering prevent it from being used as a next-generation cell factory for bio-based chemicals. In this paper, we bring together and characterise a set of native K. marxianus parts for the expression of multiple genes for metabolic engineering and synthetic biology. All parts are cloned and stored according to the MoClo/Yeast Tool Kit standard for quick sharing and rapid construction. Using available genomic and transcriptomic data, we have selected promoters and terminators to fine-tune constitutive and inducible gene expression. The collection includes a number of known centromeres and autonomously replication sequences (ARS). We also provide a number of chromosomal integration sites selected for efficiency or visible phenotypes for rapid screening. Finally, we provide a single-plasmid CRISPR/Cas9 platform for genome engineering and facilitated gene targeting, and rationally create auxotrophic strains to expand the common range of selection markers available to K. marxianus. The curated and characterised tools we have provided in this kit will serve as a base to efficiently build next-generation cell factories from this alternative yeast. Plasmids containing all parts are available at Addgene for public distribution.","Genome engineering; Kluyveromyces; Metabolic engineering; Synthetic biology; Yeast","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:92e53881-f20e-4432-9106-7fe5541d8d93","http://resolver.tudelft.nl/uuid:92e53881-f20e-4432-9106-7fe5541d8d93","Connecting central carbon and aromatic amino acid metabolisms to improve de novo 2-phenylethanol production in Saccharomyces cerevisiae","Else-Hassing, J. (TU Delft BT/Industriele Microbiologie); de Groot, P.A. (TU Delft BT/Industriele Microbiologie); Marquenie, Vita R. (Student TU Delft); Pronk, J.T. (TU Delft BT/Biotechnologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2019","The organic compound 2-phenylethanol (2PE) has a pleasant floral scent and is intensively used in the cosmetic and food industries. Microbial production of 2PE by phenylalanine bioconversion or de novo biosynthesis from sugar offer sustainable, reliable and natural production processes compared to chemical synthesis. Despite the ability of Saccharomyces cerevisiae to naturally synthesize 2PE, de novo synthesis in high concentration and yield remains a metabolic engineering challenge. Here, we demonstrate that improving phosphoenolpyruvate supply by expressing pyruvate kinase variants and eliminating the formation of p-hydroxy-phenylethanol without creating tyrosine auxotrophy significantly contributed to improve 2PE production in S. cerevisiae. In combination with the engineering of the aromatic amino acid biosynthesis and Ehrlich pathway, these mutations enabled better connection between glycolysis and pentose phosphate pathway optimizing carbon flux towards 2PE. However, attempts to further connect these two parts of central carbon metabolism by redirecting fructose-6P towards erythrose-4P by expressing a phosphoketolase-phosphotransacetylase pathway did not result in improved performance. The best performing strains were capable of producing 13mM of 2PE at a yield of 0.113 mol mol-1, which represents the highest yield for de novo produced 2PE in S. cerevisiae and other yeast species.","2-Phenylethanol; Aromatic amino acid pathway engineering; de novo biosynthesis; Prephenate dehydrogenase downregulation; Pyruvate kinase; Saccharomyces cerevisiae","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:f038eaaa-71c2-4816-9c78-fc2c03ba2110","http://resolver.tudelft.nl/uuid:f038eaaa-71c2-4816-9c78-fc2c03ba2110","Transdisciplinary systems engineering: Implications, challenges and research agenda","Wognum, Nel (TU Delft Air Transport & Operations); Bil, Cees (Royal Melbourne Institute of Technology University); Elgh, Fredrik (Jönköping University); Peruzzini, Margherita (Università Degli Studi di Modena e Reggio Emilia); Stjepandić, Josip (PROSTEP AG); Verhagen, W.J.C. (TU Delft Air Transport & Operations)","","2019","Transdisciplinary processes have been the subject of research since several decades already. Transdisciplinary processes are aimed at solving ill-defined and socially relevant problems. Many researchers have studied transdisciplinary processes and have tried to understand the essentials of transdisciplinarity. Many engineering problems can be characterised as ill-defined and socially relevant, too. Although transdisciplinary engineering cannot widely be found in the literature yet, a transdisciplinary approach is deemed relevant for many engineering problems. With this paper we aim to present an overview of the literature on research into transdisciplinary processes and investigate the relevance of a transdisciplinary approach in engineering domains. After a brief description of past research on transdisciplinarity, implications for engineering research, engineering practice, and engineering education are identified. In all three areas, the current situation is described, while challenges are identified that still exist. The paper ends with a research agenda for transdisciplinary engineering.","Engineering education; Industry 4.0; Project-based learning; Social relevance; Transdisciplinary collaboration; Transdisciplinary engineering; Transdisciplinary processes; Transdisciplinary research; Transdisciplinary systems","en","journal article","","","","","","","","2020-04-01","","","Air Transport & Operations","","",""
"uuid:b2946104-2092-42bb-a1ee-3b085d110466","http://resolver.tudelft.nl/uuid:b2946104-2092-42bb-a1ee-3b085d110466","An Empirical Evaluation of Feedback-Driven Software Development","Beller, M.M. (TU Delft Software Engineering)","Zaidman, A.E. (promotor); van Deursen, A. (promotor); Gousios, G. (copromotor); Delft University of Technology (degree granting institution)","2018","Software developers today crave for feedback, be it from their peers in the form of code review, static analysis tools like their compiler, or the local or remote execution of their tests in the Continuous Integration (CI) environment. With the advent of social coding sites such as GitHub and tight integration of CI services such as Travis CI, software development practices have fundamentally changed. Despite a highly alternated software engineering landscape, however, we still lack a suitable holistic description of contemporary software development practices. Existing descriptions such as the V-model are either too coarse-grained to describe an individual contributor’s workflow, or only regard a subpart of the development process, like Test-Driven Development (TDD). In addition, most existing models are pre- rather than de-scriptive. By contrast, in this thesis, we perform a series of empirical studies to characterize the individual constituents of Feedback-Driven Development (FDD): we study the prevalence and evolution of Automatic Static Analysis Tools (ASATs), we explain the “Last Line Effect,” a phenomenon at the boundary between ASATs and code review, we observe local testing patterns in the Integrated Development Environment (IDE) of developers, compare them to remote testing on the CI server, and, finally, should these quality assurance techniques have failed, we examine how developers debug faults. We then compile this empirical evidence into a model of how today’s software developers work. Our results show that developers employ the different techniques in FDD to best achieve their current task in the most efficient way, often knowingly taking shortcuts to get the job done. While this is efficient in the short term, it also bears risks, namely that prevention and introspection activities fall short: developers might not configure or combine ASATs to their full benefit, they might have wrong perceptions about the amount of time spent on quality-control, quality-related activities such as testing could become an after-thought, and learning about debugging techniques falls short. A relatively rigid, tool-enforced FDD process could help developers in not committing some of these mistakes. Our thesis culminates in the finding that feedback loops are the characterizing criterion of contemporary software development. Our model is flexible enough to accommodate a broad band of modern workflows, despite large variances in how projects use and configure parts of FDD.","Feedback-Driven Development (FDD); Developer Testing; Software Engineering; Continuous Integration","en","doctoral thesis","","978-94-6380-065-5","","","","","","","","","Software Engineering","","",""
"uuid:954b775c-7b59-49cc-837f-55d50e88ed1b","http://resolver.tudelft.nl/uuid:954b775c-7b59-49cc-837f-55d50e88ed1b","Catalytic performance of a class III Old yellow enzyme and its cysteine variants","Scholtissek, Anika (University of Technology Bergakademie Freiberg); Gädke, Eric (University of Technology Bergakademie Freiberg; Ruhr-Universität Bochum); Paul, C.E. (TU Delft BT/Biocatalysis; Wageningen University & Research); Westphal, Adrie H. (Wageningen University & Research); Van Berkel, Willem J.H. (Wageningen University & Research); Tischler, Dirk (Ruhr-Universität Bochum)","","2018","Class III old yellow enzymes (OYEs) contain a conserved cysteine in their active sites. To address the role of this cysteine in OYE-mediated asymmetric synthesis, we have studied the biocatalytic properties of OYERo2a from Rhodococcus opacus 1CP (WT) as well as its engineered variants C25A, C25S and C25G. OYERo2a in its redox resting state (oxidized form) is irreversibly inactivated by N-methylmaleimide. As anticipated, inactivation does not occur with the Cys variants. Steady-state kinetics with this maleimide substrate revealed that C25S and C25G doubled the turnover frequency (kcat) while showing increased KM values compared to WT, and that C25A performed more similar to WT. Applying the substrate 2-cyclohexen-1-one, the Cys variants were less active and less efficient than WT. OYERo2a and its Cys variants showed different activities with NADPH, the natural reductant. The variants did bind NADPH less well but kcat was significantly increased. The most efficient variant was C25G. Replacement of NADPH with the cost-effective synthetic cofactor 1-benzyl-1,4-dihydronicotinamide (BNAH) drastically changed the catalytic behavior. Again C25G was most active and showed a similar efficiency as WT. Biocatalysis experiments showed that OYERo2a, C25S, and C25G converted N-phenyl-2-methylmaleimide equally well (81-84%) with an enantiomeric excess (ee) of more than 99% for the R-product. With cyclic ketones, the highest conversion (89%) and ee (>99%) was observed for the reaction of WT with R-carvone. A remarkable poor conversion of cyclic ketones occurred with C25G. In summary, we established that the generation of a cysteine-free enzyme and cofactor optimization allows the development of more robust class III OYEs.","Actinobacteria; Biocatalysis; Cysteine modification; Ene reductase; Flavoprotein; Inactivation; Protein engineering; Rhodococcus opacus 1CP","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:fdc2b0f4-a106-4245-8600-35c3622d6f33","http://resolver.tudelft.nl/uuid:fdc2b0f4-a106-4245-8600-35c3622d6f33","Pipe failure modelling for water distribution networks using boosted decision trees","Winkler, Daniel (University of Innsbruck); Haltmeier, Markus (University of Innsbruck); Kleidorfer, Manfred (University of Innsbruck); Rauch, Wolfgang (University of Innsbruck); Tscheikner-Gratl, F. (TU Delft Integral Design & Management; TU Delft Sanitary Engineering)","","2018","Pipe failure modelling is an important tool for strategic rehabilitation planning of urban water distribution infrastructure. Rehabilitation predictions are mostly based on existing network data and historical failure records, both of varying quality. This paper presents a framework for the extraction and processing of such data to use it for training of decision tree-based machine learning methods. The performance of trained models for predicting pipe failures is evaluated for simple as well as more advanced, ensemble-based, decision tree methods. Bootstrap aggregation and boosting techniques are used to improve the accuracy of the models. The models are trained on 50% of the available data and their performance is evaluated using confusion matrices and receiver operating characteristic curves. While all models show very good performance, the boosted decision tree approach using random undersampling turns out to have the best performance and thus is applied to a real world case study. The applicability of decision tree methods for practical rehabilitation planning is demonstrated for the pipe network of a medium sized city.","decision support systems; Deterioration; environmental engineering; rehabilitation; statistical models; water supply","en","journal article","","","","","","","","","","","Integral Design & Management","","",""
"uuid:f8cb0602-d19d-48ac-bc5a-46e3c48ea4c1","http://resolver.tudelft.nl/uuid:f8cb0602-d19d-48ac-bc5a-46e3c48ea4c1","Information engineering for supporting situation awareness of nautical traffic management operators","van Doorn, E.C. (TU Delft Cyber-Physical Systems)","Horvath, I. (promotor); Rusak, Z. (copromotor); Delft University of Technology (degree granting institution)","2018","The main challenge of operators working with complex information systems is to gain sufficient situation awareness (SA). In this research project, we developed an analysis scheme to support a holistic study of SA. This analysis scheme was complemented with a method to process cognitive task analysis and observational research data to identify deficiencies of systems in supporting SA. This approach was applied in nautical traffic management practice. In total we identified 30 deficiencies, of which 23 were related to how the system interfaces support human information processing. The commonly applied user-centered design method was insufficient to overcome the identified deficiencies. User-centered design therefore was complemented with information engineering (IE) methods for analyzing relationships between information elements and for specifying UI design. Application of different IE methods resulted in the development of three UI concepts; a coherent, an integrated and a context-dependent adaptable UI. The generated UI concepts were tested using a nautical traffic management workplace simulator. Usability testing showed that the proposed IE approach had a positive effect on the effectiveness, efficiency and user satisfaction. Evaluation of the impact of the UI prototypes showed that the application of a graph theory based IE approach had positive effects on operators’ speed of gaining SA, speed of communication with priority stakeholders, and the likeliness that operators executed necessary actions in the required order. Application of semantic networks resulted in a UI which provided better support of answering questions of skippers related to future states of the traffic management environment.","situation awareness; traffic management; Information engineering; User Interfaces and Human Computer Interaction; Research Through Design","en","doctoral thesis","","978-94-6186-929-6","","","","","","","","","Cyber-Physical Systems","","",""
"uuid:e6e484ec-ae0b-4355-a837-460b4b93484e","http://resolver.tudelft.nl/uuid:e6e484ec-ae0b-4355-a837-460b4b93484e","Engineering de novo anthocyanin production in Saccharomyces cerevisiae","Levisson, Mark (Wageningen University & Research); Patinios, Constantinos (Wageningen University & Research); Hein, Sascha (Centro Ricerca e Innovazione); de Groot, P.A. (TU Delft Applied Sciences); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Martens, Stefan (Centro Ricerca e Innovazione); Hall, Robert D. (Wageningen University & Research); Beekwilder, Jules (Wageningen University & Research)","","2018","Background: Anthocyanins are polyphenolic pigments which provide pink to blue colours in fruits and flowers. There is an increasing demand for anthocyanins, as food colorants and as health-promoting substances. Plant production of anthocyanins is often seasonal and cannot always meet demand due to low productivity and the complexity of the plant extracts. Therefore, a system of on-demand supply is useful. While a number of other (simpler) plant polyphenols have been successfully produced in the yeast Saccharomyces cerevisiae, production of anthocyanins has not yet been reported. Results: Saccharomyces cerevisiae was engineered to produce pelargonidin 3-O-glucoside starting from glucose. Specific anthocyanin biosynthetic genes from Arabidopsis thaliana and Gerbera hybrida were introduced in a S. cerevisiae strain producing naringenin, the flavonoid precursor of anthocyanins. Upon culturing, pelargonidin and its 3-O-glucoside were detected inside the yeast cells, albeit at low concentrations. A number of related intermediates and side-products were much more abundant and were secreted into the culture medium. To optimize titers of pelargonidin 3-O-glucoside further, biosynthetic genes were stably integrated into the yeast genome, and formation of a major side-product, phloretic acid, was prevented by engineering the yeast chassis. Further engineering, by removing two glucosidases which are known to degrade pelargonidin 3-O-glucoside, did not result in higher yields of glycosylated pelargonidin. In aerated, pH controlled batch reactors, intracellular pelargonidin accumulation reached 0.01 μmol/gCDW, while kaempferol and dihydrokaempferol were effectively exported to reach extracellular concentration of 20 μM [5 mg/L] and 150 μM [44 mg/L], respectively. Conclusion: The results reported in this study demonstrate the proof-of-concept that S. cerevisiae is capable of de novo production of the anthocyanin pelargonidin 3-O-glucoside. Furthermore, while current conversion efficiencies are low, a number of clear bottlenecks have already been identified which, when overcome, have huge potential to enhance anthocyanin production efficiency. These results bode very well for the development of fermentation-based production systems for specific and individual anthocyanin molecules. Such systems have both great scientific value for identifying and characterising anthocyanin decorating enzymes as well as significant commercial potential for the production of, on-demand, pure bioactive compounds to be used in the food, health and even pharma industries.","Anthocyanin; Flavonoids; Metabolic engineering; Natural products; Pelargonidin; Plant secondary metabolites; Saccharomyces cerevisiae","en","journal article","","","","","","","","","Applied Sciences","","BT/Industriele Microbiologie","","",""
"uuid:bc9f6b58-98f8-4eeb-ac89-49c3ba70e2a1","http://resolver.tudelft.nl/uuid:bc9f6b58-98f8-4eeb-ac89-49c3ba70e2a1","Pareto-based maintenance decisions for regional railways with uncertain weld conditions using the Hilbert spectrum of axle box acceleration","Nunez, Alfredo (TU Delft Railway Engineering); Jamshidi, A. (TU Delft Railway Engineering); Wang, H. (TU Delft Railway Engineering)","","2018","This paper presents a Pareto-based maintenance decision system for rail welds in a regional railway network. Weld health condition data are collected using a train in operation. A Hilbert spectrum-based approach is used for data processing to detect and assess the weld quality based on multiple registered dynamic responses in the axle box acceleration measurements. The assessment of the welds is stochastic in nature and variant over time, so a set of robust and predictive key performance indicators is defined to capture the weld degradation dynamics during a given maintenance period. Using a scenario-based approach, two objective functions are defined, performance and the number of weld replacements. Evolutionary multi-objective optimization is employed to optimize the objective functions so that the trade-offs between performance and cost support decision-making for railway network maintenance. The results of the proposed methodology show that the infrastructure manager can localize field inspections and maintenance efforts on the area with the most critical welds. To showcase the capability of the proposed methodology, measurements from a regional railway network in Transylvania, Romania are employed.","Acceleration; Acceleration measurements; Axles; Degradation; Evolutionary multi-objective optimization; Maintenance; Maintenance engineering; Rail transportation; Rails; Railway infrastructure; Welding","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-12-15","","","Railway Engineering","","",""
"uuid:44dda417-a658-47d3-998b-48c082c9e989","http://resolver.tudelft.nl/uuid:44dda417-a658-47d3-998b-48c082c9e989","A tensor approach to linear parameter varying system identification","Gunes, Bilal (TU Delft Team Jan-Willem van Wingerden)","van Wingerden, J.W. (promotor); Verhaegen, M.H.G. (promotor); Delft University of Technology (degree granting institution)","2018","","tensor; LPV; identification; data-driven; wind; turbine; statistics; subspace; optimization; tensor decompositions; multi-linear algebra; SVD; MLSVD; HOSVD; tensor trains; tensor networks; polyadic; engineering; wind energy","en","doctoral thesis","","","","","","","","","","","Team Jan-Willem van Wingerden","","",""
"uuid:0e3a2402-585c-41b1-81cf-a35753076dfc","http://resolver.tudelft.nl/uuid:0e3a2402-585c-41b1-81cf-a35753076dfc","The wake of an unsteady actuator disc","Yu, W. (TU Delft Wind Energy)","van Kuik, G.A.M. (promotor); Ferreira, Carlos (copromotor); Delft University of Technology (degree granting institution)","2018","Blade Element Momentum (BEM) is the most important aerodynamic analysis method for wind turbines. BEM is derived assuming stationary conditions, which limits its ability to model the unsteady aerodynamic effects. This becomes increasingly relevant for the flexible blades of current large-scale turbines, and the employment of passive and active aerodynamic control strategies, such as yaw, pitch control and smart rotor control. Currently, sub-models are included to consider the unsteady aerodynamic effects for wind turbine design. Previous research developed several dynamic-inflow engineering models to be integrated into BEM, to account for the unsteady flow acceleration. However, their applicability for unsteady load and the relative performance between the models are not fully known. The development of the dynamic wake of an actuator disc under unsteady load needs further understanding, to improve the engineering prediction of dynamic-inflow effect. This research aims to evaluate the accuracy of BEM with current dynamic-inflow engineering models; to further understand the dynamic wake flow-field of an actuator disc undergoing unsteady load; to improve current dynamic-inflow engineering models for wind turbine design using numerical and experimental approaches. A free wake vortex ring (FWVR) model is firstly developed. The accuracy of BEM with current dynamic-inflow engineering models of Pitt-Peters, Øye and ECN in predicting the induction of an actuator disc with unsteady load is verified using the developed FWVR model. The wake flow response of an actuator disc undergoing unsteady loads is studied experimentally by using a disc model with variable porosity. The unsteady load is generated by a ramp type variation of porosity of the disc, at several reduced times of the ramp motion. The wake development of an actuator disc undergoing the same unsteady load tested in the experiments is further studied using the FWVR model. The steady actuator-disc model is extended to unsteady load. Results from this linear actuator-disc model are compared with those from the FWVR model. Finally, a new engineering model is developed using the differential form of the Duhamel’s integrals of indicial response of the actuator-disc type vortex-models. The time constants of the indicial functions are obtained by the indicial responses of a linear and a nonlinear actuator-disc model, respectively. The work provides more insights into the wake development of an unsteady actuator disc. The experimental results create a database for validation of unsteady numerical models, in prediction of the dynamic induction in the near wake of an actuator disc or a rotor. The limitation of current dynamic-inflow engineering models are evaluated and discussed. The new engineering model, which is developed based on the indicial response of the nonlinear actuator-disc model, can better predict the dynamic-inflow effects, especially for the radial distribution of the dynamic-inflow effect.","dynamic inflow; actuator disc; free wake vortex ring; unsteady load; engineering model","en","doctoral thesis","","978-94-6366-020-4","","","","","","","","","Wind Energy","","",""
"uuid:3acfe30a-1c01-4851-b491-ca20b3b459ce","http://resolver.tudelft.nl/uuid:3acfe30a-1c01-4851-b491-ca20b3b459ce","Data assimilation in the minerals industry: Real-time updating of spatial models using online production data","Wambeke, T. (TU Delft Resource Engineering)","Jansen, J.D. (promotor); Benndorf, J. (promotor); Delft University of Technology (degree granting institution)","2018","Declining ore grades, extraction at greater depths and longer hauling distances put pressure on maturing mines. Not enough new mines will be commissioned on time to compensate for the resulting shortages. Ore-body replacement rates are relatively low due to a reduced appetite for exploration. Development times are generally increasing and most new projects are remote, possibly pushing costs further upwards.
To reverse these trends, the industry must collect, analyse and act on information to extract and process material more productively (i.e. maximize resource efficiency). This paradigm shift, driven by digital innovations, aims to (partly) eliminate the external variability that has made mining unique. The external variability results from the nature of the resource being mined. This type of variability can only be controlled if the resource base is sufficiently characterized and understood.
Recent developments in sensor technology enable the online characterization of raw material characteristics and equipment performance. To date, such measurements are mainly utilized in forward loops for downstream process control. A backward integration of sensor information into the resource model does not yet occur. Obviously, such a backward integration would significantly contribute to the progressive characterization of the resource base.
This dissertation presents a practical updating algorithm to continuously assimilate recently acquired data into an already existing resource model. The updating algorithm addresses the following practical considerations. (a) At each point in time, the latest solution implicitly accounts for all previously integrated data (sequential approach). During the next update, the already existing resource model is further adjusted to honour the newly obtained observations as well. (b) Due to the nature of a mining operation, it is nearly impossible to formulate closed-form analytical expressions de- scribing the relationship between observations and resource blocks. Rather, the relevant relationships are merely inferred from the inputs (the resource model realizations) and outputs (distribution of predicted observations) of a forward simulator. (c) The updating algorithm is able to assimilate noisy observations made on a blend of material originating from multiple sources and locations. Differences in scale of support are dealt with automatically.
The developed algorithm integrates concepts from several existing (geo)statistical techniques. Co-Kriging approaches for example are designed to integrate both direct and indirect measurements and are well capable to handle differences in accuracy and sampling volume. However, they do fail to extract information from blended measurements and can not sequentially incorporate new observations into an already existing resource model. To overcome the latter issue, the co-Kriging equations are merged into a sequential linear estimator. Existing resource models can now be improved using a weighted sum of differences between observations and model-based predictions (forward simulator output). The covariances, necessary to compute the weights, are empirically derived from two sets of Monte Carlo samples (another sta- tistical technique); the resource model realizations (input forward simulator) and the observation realizations (output forward simulator). This approach removes the need to formulate analytical functions modelling spatial correlations, blending and difference in scale of support.
The resulting mathematical framework bears some resemblances to that of a dy- namic filter (Ensemble Kalman filter), used in other research areas, althoughthe under- lying philosophy differs significantly. Weather forecasting and reservoir modelling, for example, consider dynamic systems repetitively sampled at the same locations. Each observation characterizes a volume surrounding the sample locations. Mineral resource modelling, on the other hand, focuses on static systems gradually sampled at different locations. Each observation is characteristic for a blend of material originating from multiple sources and locations. Each part of the material stream is sampled only once, the moment it passes the sensor.
Various options are implemented around the mathematical framework to either reduce computation time, memory requirements or numerical inaccuracies. (a) A Gaussian anamorphosis is included to deal with suboptimal conditions related to non- Gaussian distributions. The algorithm structure ensures that the sensor precision (mea- surement error) can be defined on its original units and does not need to be translated into a normal score equivalent. (b) An interconnected parallel updating sequence (double helix) can be configured to avoid a covariance collapse (filter inbreeding). This occurs as degrees of freedom are lost over time due to the empirical calculation of the covariances. (c) A neighbourhood option is implemented to constrain computation time and memory requirements. Different neighborhoods need to be considered simul- taneously as material streams are blended. (d) Two covariance correction options are implemented to further inhibit the propagation of statistical sampling errors originating from the empirical computation of covariances.
A case specific forward simulator is built and run parallel to the more generally applicable updating code. The forward simulator is used to translate resource model realizations (input) into observation realizations (output). Empirical covariances are subsequently lifted from both realization sets and mathematically describe the link between sensor observations and individual blocks in the model. This numerical inference avoids the cumbersome task of formulating, linearising and inverting an analytical forward observation model. The application of a forward simulator further ensures that the distribution of the Monte Carlo samples already reflect the support of the concerned random values. As a result, the necessary covariances, derived from these Monte Carlo samples, inherently account for differences in scale of support.
A synthetic experiment is conducted to showcase that the algorithm is capable of assimilating inaccurate observations, made on blended material streams, into an already existing resource model. The experiment is executed in an artificial environment, representing a mining environment with two extraction points of unequal production rate. A visual inspection of cross-sections shows that the model converges towards the ”true but unknown reality”. Global assessment statistics quantitatively confirm this observation. Local assessment statistics further indicate that the global improvements mainly result from correcting local estimation biases.
Another 125 artificial experiments are conducted to study the effects of variations in measurement volume, blending ratio and sensor precision. The experiments investigate whether and how the resource model and the predicted observations improve over time. Based on the outcome, recommendations are formulated to optimally design and operate a monitoring system.
This work further describes the pilot testing of the updating algorithm at the Tropi- cana Gold Mine (Australia). The pilot aims to evaluate whether the updating algorithm can automatically reconcile ball mill performance data against the spatial Work Index estimates of the GeoMet model. The focus here lies on the ball mill since it usually is the single largest energy consumer at the mine site. The spatial Work Index estimates are used to predict a ball mill’s throughput. In order to maximize mill throughput and optimize energy utilization, it is important to get the Work Index estimates right. At the Tropicana Gold Mine, Work Index estimates, derived from X-Ray Fluorescence and Hyperspectral scanning of grade control samples, are used to construct spatial GeoMetallurgical models (GeoMet). Inaccuracies in the block estimates exist due to limited calibration between grade control derived and laboratory Work Index values. To improve the calibration, the updating algorithm was tested at the mine during a pilot study. Deviations between predicted and actual mill performance are monitored and used to locally improve the Work Index estimates in the GeoMet model. While assim- ilating about a week of mill performance data, the spatial GeoMet model converged towards a previously unknown reality. The updating algorithm improved the spatial Work Index estimates, resulting in a real-time reconciliation of already extracted blocks and a recalibration of future scheduled blocks. The case study shows that historic and future production estimates improve on average by about 72% and 26%.","Geostatistics; Data Assimilation; geometallurgy; resource engineering; mining; Discrete event simulation; material tracking","en","doctoral thesis","","978-94-6186-904-3","","","","","","","","","Resource Engineering","","",""
"uuid:f8fa946a-0178-40e7-bf9c-b91962698481","http://resolver.tudelft.nl/uuid:f8fa946a-0178-40e7-bf9c-b91962698481","Evidence-Based Software Portfolio Management","Huijgens, H.K.M. (TU Delft Software Engineering)","van Deursen, A. (promotor); van Solingen, D.M. (promotor); Delft University of Technology (degree granting institution)","2018","Based on the large amounts spent by software companies to develop new and existing software systems, we argue that an evidence-based approach that focuses on a software portfolio as a whole should be in place to support decision-making. We developed EBSPM as an evidence-based, practical model to support software companies to actively steer at optimization of their software delivery portfolio. We evaluated the model in case studies and surveys in industry, to demonstrate its strengths and limitations in practice. This lead to the following results:
• We analyzed - from a portfolio point of view - the characteristics of best performers and worst performers, in a dataset of 352 software projects, resulting in 7 success factors and 9 failure factors.
• We found that a release process that performs above average on cost and duration, satisfies stakeholders through fast response and direct value, even when the reliability and availability of the actual system are weak.
• A statistical, evidence-based pricing approach for software engineering, as a single instrument, can be used in the subject companies to create cost transparency and performance management.
• We found significant differences between the EBSPM-repository and an ISBSG-subset. Practitioners and researchers alike should be cautious when drawing conclusions from a single repository.
• We found that a focus on shortening overall project duration and improving communication and team collaboration on intermediate progress is likely to have a positive impact on stakeholder satisfaction and perceived value.
Based on the findings, we conclude that it is wise for software companies to collect and analyze their own historic software portfolio data because cross-company large differences in performance are found. We obtained a better understanding of the differences and equalities between effort and cost of software deliveries. Additionally, we studied the effects of pricing of software deliveries, giving us a better insight into ways to support decision-making. Based on the results of ongoing research, we expect that automation of the measurement and analysis process, based on statistics to calculate strong relationships, is a direction in which the analysis of software portfolio (software analytics) is the to develop strongly in the coming years.
Here the morphological development of the Sand Engine mega feeder nourishment and the adjacent coastal sections is presented. This study is based on 37 high-resolution topographical surveys, spanning a coastal cell of 17 km alongshore. These data are explored to examine the alongshore spreading in the first five years after construction in 2011, as well as the response at different depth contours in the coastal profile.
The analysis shows that the highly concentrated nourishment supplies sediment to a stretch of coast that is several times the initial length of the nourishment, as the size of the Sand Engine peninsula increased from 2.2 to 5.8km alongshore. The plan-form shape of the peninsula is found to gradually extend alongshore, while reducing in cross-shore extent. This behaviour is found to vary strongly with depth contours. The strongest response was found around the mean sea level iso-bath in contrast to the deeper parts and Aeolian parts of the Sand Engine. This variability in response over depth results in different profile slope development in accretive and erosive areas. In coastal sections which are eroding the sub-tidal slope decreases, while accretive profiles experience a profile slope increment over time. The cross shore extent of the morphologic response shows limited morphodynamic activity below the -8m NAP depth contour and confirms earlier assessments of closure depth at this coast.
The current findings at the Sand Engine imply that mega feeder nourishments can be beneficial to the sediment budget of a larger coastal cell. However, volumes that are deposited around or below the depth of closure (around 15 % for the Sand Engine) may react on much longer time-scales than intended. Therefore, the feeding characteristics of mega feeder nourishments on time-scales of years should be assessed using the nourished volumes above the depth of closure rather than the total volume.","Sand Engine; Sand Motor; Delfland; Sediment transport","en","abstract","","","","","","Abstract to the presentation given at the NCK days 2018.","","","","","Coastal Engineering","","",""
"uuid:510bd39f-407d-4bb6-958e-dea363c5e2a8","http://resolver.tudelft.nl/uuid:510bd39f-407d-4bb6-958e-dea363c5e2a8","Planetary-scale surface water detection from space","Donchyts, G. (TU Delft Water Resources; Deltares)","van de Giesen, N.C. (promotor); Delft University of Technology (degree granting institution)","2018","This thesis studies automated methods of surface water detection from satellite imagery. Multiple existing methods are explored, discussed, and some new algorithms are introduced to allowvery accurate detection of surface water and surfacewater changes. Themethods range in applicability from the local level to global, and from detecting high-frequency changes to low-frequency changes. Their trade-offs regarding the accuracy and applicability of the surface water detection methods are also discussed.
Several applications are presented to test the introduced methods. One of the studies focuses on a long-term global surface water change detection over the past 30 years at 30m resolution. The other application looks at the generation of a permanent surface water mask for Murray-Darling River Basin in Australia. Additionally, an in-depth validation for a small reservoir in California, USA is presented, to demonstrate performance of the new methods.
The algorithms discussed in the thesis were applied and tested to process both passive optical multispectral and active Synthetic Aperture Radar (SAR) satellite data. Combining data fromall freely available satellite sensors requires harmonizations of the satellite data, but also, significant computing resources. In this thesis, Google Earth Engine parallel processing platformwas used to performmost of the experiments.
We will see, thatwhen studying surface water dynamics, the best results can be achieved by combining discriminative and generative methods of surface water detection. This way, the surface water can also be detected from satellite images where surface water is only partially visible.
In the thesis, top-of-atmosphere reflectance images are used to detect surface water. The atmospheric correction is not required when dynamic local thresholding methods are used to detect surface water.","surface water observation; satellite imagery; unsupervised classification; NDWI; landsat; sentinel; SRTM; google earth engine","en","doctoral thesis","","978-94-6233-862-3","","","","","","","","","Water Resources","","",""
"uuid:a56fedf2-4bc0-495e-8d31-95cdd4de213e","http://resolver.tudelft.nl/uuid:a56fedf2-4bc0-495e-8d31-95cdd4de213e","Blending technological, cognitive and social enablers to develop an immersive virtual learning environment for construction engineering education","Keenaghan, G.N. (TU Delft Cyber-Physical Systems)","Horvath, I. (promotor); Delft University of Technology (degree granting institution)","2018","The conceptual framework of the proposed novel system was to provide a stimulating learning experience for dislocated digital learners, who are seen as individuals with different perceptions and expectations. In addition to functionally integrate technological, cognitive and social enablers, the system was required to encapsulate what can be called the principles of cyber psychology. This research was not specifically about using game theories as a means of providing motivation and engagement. It was more about using technological enablers such as game engine software development kits and compatible 3D modelling software to blend with cognitive and social enablers as a conceptual design framework to develop web-based stimulated-learning systems.","Web-based learning system; technological enablers; cognitive enablers; social enablers; dis-located learners; co-located learners; 3D modelling software; game engine software; virtual environments; augmented environments; virtual learning environments","en","doctoral thesis","","978-94-6186-857-2","","","","","","","","","Cyber-Physical Systems","","",""
"uuid:549794c9-ff18-4bff-b8a5-6c41eaed5f21","http://resolver.tudelft.nl/uuid:549794c9-ff18-4bff-b8a5-6c41eaed5f21","Cross-shore stratified tidal flow seaward of a mega-nourishment","Meirelles, Saulo (TU Delft Coastal Engineering); Henriquez, M. (TU Delft Coastal Engineering); Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics); Luijendijk, Arjen (TU Delft Coastal Engineering; Deltares); Pietrzak, J.D. (TU Delft Environmental Fluid Mechanics); Horner-Devine, Alexander R. (University of Washington); Souza, Alejandro J. (National Oceanography Center); Stive, M.J.F. (TU Delft Coastal Engineering)","","2018","The Sand Engine is a 21.5 million m3 experimental mega-nourishment project that was built in 2011 along the Dutch coast. This intervention created a discontinuity in the previous straight sandy coastline, altering the local hydrodynamics in a region that is influenced by the buoyant plume generated by the Rhine River. This work investigates the response of the cross-shore stratified tidal flow to the coastal protrusion created by the Sand Engine emplacement by using a 13 h velocity and density survey. Observations document the development of strong baroclinic-induced cross-shore exchange currents dictated by the intrusion of the river plume fronts as well as the classic tidal straining which are found to extend further into the nearshore (from 12 to 6m depth), otherwise believed to be a mixed zone. Estimates of the centrifugal acceleration directly after construction of the Sand Engine showed that the curvature effects were approximately 2 times stronger, suggesting that the Sand Engine might have played a role in controlling the cross-shore exchange currents during the first three years after the completion of the nourishment. Presently, the curvature effects are minute.","Baroclinic forcing; Centrifugal acceleration; Cross-shore exchange currents; Sand Engine","en","journal article","","","","","","","","2019-12-22","","","Coastal Engineering","","",""
"uuid:c901c0bb-a5ac-426b-af55-6644c731df38","http://resolver.tudelft.nl/uuid:c901c0bb-a5ac-426b-af55-6644c731df38","From Learners to Earners: Enabling MOOC Learners to Apply Their Skills and Earn Money in an Online Market Place","Chen, G. (TU Delft Web Information Systems); Davis, D.J. (TU Delft Web Information Systems); Krause, Markus (University of California); Aivaloglou, E.A. (TU Delft Software Engineering); Hauff, C. (TU Delft Web Information Systems); Houben, G.J.P.M. (TU Delft Web Information Systems)","","2018","Massive Open Online Courses (MOOCs) aim to educate the world. More often than not, however, MOOCs fall short of this goal — a majority of learners are already highly educated (with a Bachelor degree or more) and come from specific parts of the (developed) world. Learners from developing countries without a higher degree are underrepresented, though desired, in MOOCs. One reason for those learners to drop out of a course can be found in their financial realities and the subsequent limited amount of time they can dedicate to a course besides earning a living. If we could pay learners to take a MOOC, this hurdle would largely disappear. With MOOCS, this leads to the following fundamental challenge: How can learners be paid at scale? Ultimately, we envision a recommendation engine that recommends tasks from online market places such as Upwork or witmart to learners, that are relevant to the course content of the MOOC. In this manner, the learners learn and earn money. To investigate the feasibility of this vision, in this paper we explored to what extent (1) online market places contain tasks relevant to a specific MOOC, and (2) learners are able to solve real-world tasks correctly and with sufficient quality. Finally, based on our experimental design, we were also able to investigate the impact of real-world bonus tasks in a MOOC on the general learner population.","Data analysis; Uncertainty; Monitoring; Process control; Education; Engines; Sociology","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-12-01","","","Web Information Systems","","",""
"uuid:6c4dd1d7-2bc1-4770-b8cb-d52360532b72","http://resolver.tudelft.nl/uuid:6c4dd1d7-2bc1-4770-b8cb-d52360532b72","On the anatomy of social engineering attacks: A literature-based dissection of successful attacks","Bullée, Jan Willem Hendrik (University of Twente); Montoya, Lorena (University of Twente); Pieters, W. (TU Delft Safety and Security Science); Junger, M. (University of Twente); Hartel, P.H. (TU Delft Cyber Security)","","2018","The aim of this study was to explore the extent to which persuasion principles are used in successful social engineering attacks. Seventy-four scenarios were extracted from 4 books on social engineering (written by social engineers) and analysed. Each scenario was split into attack steps, containing single interactions between offender and target. For each attack step, persuasion principles were identified. The main findings are that (a) persuasion principles are often used in social engineering attacks, (b) authority (1 of the 6 persuasion principles) is used considerably more often than others, and (c) single-principle attack steps occur more often than multiple-principle ones. The social engineers identified in the scenarios more often used persuasion principles compared to other social influences. The scenario analysis illustrates how to exploit the human element in security. The findings support the view that security mechanisms should include not only technical but also social countermeasures.","Deception; Information security; Literature study; Persuasion; Social engineering","en","journal article","","","","","","","","","","","Safety and Security Science","","",""
"uuid:cb2eb4bb-b829-442c-b2ca-8fa77da04f8e","http://resolver.tudelft.nl/uuid:cb2eb4bb-b829-442c-b2ca-8fa77da04f8e","Physical Location of Smart Key Activators: A Building Security Penetration Test","Bullée, Jan Willem (University of Twente); Montoya Morales, A.L. (University of Twente); Junger, M. (University of Twente); Hartel, P.H. (TU Delft Cyber Security)","","2018","Purpose – When security managers choose to deploy a smart lock activation system, the number of units needed and their location needs to be established. This study presents the results of a penetration test involving smart locks in the context of building security. We investigated how the amount of effort an employee has to invest in complying with a security policy (i.e. walk from the office to the smart key activator) influences vulnerability. In particular, the attractiveness of a no-effort alternative (i.e. someone else walking from your office to the key activators to perform a task on your behalf) was evaluated. The contribution of this study relates to showing how experimental psychology can be used to determine the cost-benefit analysis (CBA) of physical building security measures.
Design/methodology/approach – Twenty-seven different ‘offenders’ visited the offices of 116 employees. Using a script, each offender introduced a problem, provided a solution and asked the employee to hand over their office key.
Findings – A total of 58.6% of the employees handed over their keys to a stranger; no difference was found between female and male employees. The likelihood of handing over the keys for employees close to a key activator was similar to that of those who were further away.Research limitations/implications – The results suggest that installing additional key activators is not conducive to reducing the building’s security vulnerability associated with the handing over of keys to strangers.
Originality/value – No research seems to have investigated the distribution of smart key activators in the context of a physical penetration test. This research highlights the need to raise awareness of social engineering and of the vulnerabilities introduced via smart locks (and other smart systems).","Building layout; Building Management; Distance decay; Smart key; Security; Social engineering","en","journal article","","","","","","Accepted Author Manuscript","","","","","Cyber Security","","",""
"uuid:b2cfe194-e0f8-4e0c-a0e0-9cd9793a31d8","http://resolver.tudelft.nl/uuid:b2cfe194-e0f8-4e0c-a0e0-9cd9793a31d8","Advancing disaster risk reduction through the integration of science, design, and policy into eco-engineering and several global resource management processes","Whelchel, Adam W. (The Nature Conservancy); Reguero, Borja G. (University of California); van Wesenbeeck, B (TU Delft Coastal Engineering; Deltares); Renaud, Fabrice G. (United Nations University)","","2018","By the later part of the 21st Century, our planet will be faced with compelling climatic circumstances requiring tradeoffs to maintain viable environmental conditions and standards of living. The prognosis for people near coastlines and waterways is particularly dire without decisive actions that capitalize on shared strengths such as ecosystems. One clear opportunity is the regenerative services and co-benefits of natural infrastructure that reduce the impacts of environmental disasters as magnified by climatic change. Certainly, nature-based solutions are increasingly being viewed as critical actions to reduce societal risk. However, to advance the use of natural infrastructure through eco-engineering, there is a need to clarify the science regarding risk reduction effectiveness, develop agreeable principles, standards, and designs, and grow a demonstration site network responsive to circumstances faced by communities around the globe. In addition, there is a need to consider the legal, policy, and regulatory obstacles and opportunities for natural infrastructure within local to national contexts (i.e., science-based building codes, architectural design criteria, incentive policies, etc.). Ultimately, the integration of science, designs, and policy coupled with installation within several global resource management processes versus global resource frames (IWRM, ICZM, etc.) will help establish eco-engineering standards. Supportive coastal, river, and urban examples from around the world are used to illustrate the current state of knowledge, model this integration of science, design, and policy, serve as initial ""benchmark site"", and finally help define guiding principles for the emerging field of eco-engineering.","Community resilience building; Disaster risk reduction; Eco-engineering; Floodplain by design; Integrated coastal zone management; Integrated water resource management","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-08-22","","","Coastal Engineering","","",""
"uuid:b8a30627-98d6-4a4c-9107-98e20199c512","http://resolver.tudelft.nl/uuid:b8a30627-98d6-4a4c-9107-98e20199c512","Classifying code comments in Java Mobile Applications","Pascarella, L. (TU Delft Software Engineering)","","2018","Developers adopt code comments for different reasons such as document source codes or change program flows. Due to a variety of use scenarios, code comments may impact on readability and maintainability. In this study, we investigate how developers of 5 open-source mobile applications use code comments to document
their projects. Additionally, we evaluate the performance of two machine learning models to automatically classify code comments. Initial results show marginal differences between desktop and mobile applications.","Software and its engineering; Maintaining software","en","conference paper","","","","","","Acknowledgments: European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642954","","","","","Software Engineering","","",""
"uuid:b5151d16-80a9-4dde-821a-3f691ac8abbe","http://resolver.tudelft.nl/uuid:b5151d16-80a9-4dde-821a-3f691ac8abbe","A topology of shared control systems: Finding common ground in diversity","Abbink, D.A. (TU Delft Human-Robot Interaction); Carlson, Tom (University College London (UCL)); Mulder, M. (TU Delft Human-Robot Interaction); de Winter, J.C.F. (TU Delft Biomechatronics & Human-Machine Control); Aminravan, Farzad (University of British Columbia); Gibo, T.L. (TU Delft Biomechatronics & Human-Machine Control); Boer, E.R. (TU Delft Human-Robot Interaction)","","2018","Shared control is an increasingly popular approach to facilitate control and communication between humans and intelligent machines. However, there is little consensus in guidelines for design and evaluation of shared control, or even in a definition of what constitutes shared control. This lack of consensus complicates cross fertilization of shared control research between different application domains. This paper provides a definition for shared control in context with previous definitions, and a set of general axioms for design and evaluation of shared control solutions. The utility of the definition and axioms are demonstrated by applying them to four application domains: automotive, robot-assisted surgery, brain–machine interfaces, and learning. Literature is discussed for each of these four domains in light of the proposed definition and axioms. Finally, to facilitate design choices for other applications, we propose a hierarchical framework for shared control that links the shared control literature with traded control, co-operative control, and other human–automation interaction methods. Future work should reveal the generalizability and utility of the proposed shared control framework in designing useful, safe, and comfortable interaction between humans and intelligent machines.","Automation; Automotive engineering; Control systems; Human-automation interaction; machine interaction; robot interaction (HRI); Mobile robots; Robot sensing systems; shared control; supervisory control; Task analysis; traded control cooperation","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-11-01","","","Human-Robot Interaction","","",""
"uuid:dcec56b3-b647-4021-8d3d-50a0e4944bca","http://resolver.tudelft.nl/uuid:dcec56b3-b647-4021-8d3d-50a0e4944bca","Push-off forces in elite short-track speed skating","van der Kruk, E. (TU Delft Biomechatronics & Human-Machine Control); Reijne, M.M. (TU Delft Biomechatronics & Human-Machine Control); de Laat, Bjorn (Dutch National Speed Skating Federation); Veeger, H.E.J. (TU Delft Biomechatronics & Human-Machine Control; Vrije Universiteit Amsterdam)","","2018","This study performed an analysis of the push-off forces of elite-short-track speed skaters using a new designed instrumented short-track speed skate with the aim to improve short-track skating performance. Four different skating strokes were distinguished for short-track speed skaters at speed. The strokes differed in stroke time, force level in both normal and lateral directions, and the centre of pressure (COP) on the blade. Within the homogeneous group of male elite speed skaters (N = 6), diversity of execution of the force patterns in the four phases of skating was evident, while skating at the same velocities. The male participants (N = 6) with a better personal record (PR) kept the COP more to the rear of their blades while hanging into the curve (r = 0.82, p < 0.05), leaving the curve (r = 0.86, p < 0.05), and entering the straight (r = 0.76, p < 0.10). Furthermore, the male skaters with a better PR showed a trend of a lower lateral peak force while entering the curve (r = 0.74, p < 0.10). Females showed a trend towards applying higher body weight normalised lateral forces than the males, while skating at imposed lower velocities.","Engineering; force measurement; performance; techniques","en","journal article","","","","","","","","","","","Biomechatronics & Human-Machine Control","","",""
"uuid:3211c46e-107a-4c22-a575-17782e418f94","http://resolver.tudelft.nl/uuid:3211c46e-107a-4c22-a575-17782e418f94","Lifetime comparison of power semiconductors in three-level converters for 10MW wind turbine systems","Shipurkar, U. (TU Delft DC systems, Energy conversion & Storage); Lyrakis, E. (TU Delft Delft Energy Initiative); Ma, Ke (Shanghai Jiao Tong University); Polinder, H. (TU Delft Transport Engineering and Logistics); Ferreira, Jan Abraham (TU Delft ESE Programmes)","","2018","The power electronic converter, especially the power semiconductor, is a major contributor to the failure rates of the wind turbine drivetrain. As the temperature is a major driving factor behind the failure mechanisms of these power semiconductors the choice of topology and switching strategy can have a significant effect on the reliability of the converter. This paper presents a detailed comparison of several three level converter topologies and switching strategies on the basis of loss distribution, thermal, and lifetime performance. This investigation is done through simulations on a 10MW direct drive permanent magnet drivetrain. The study shows that over-rating in the form of using overrated topologies, or the use of overrated components can result in large gains in lifetime expectancy and quantifies these gains. It concludes that the improvements offered by overrated topologies and overrated components are comparable and that use of the overrated topologies do not offer a significant advantage over the use of topologies with overrated components.","Direct Drive PM Generator; Failure analysis; Lifetime Estimation; Maintenance engineering; Multilevel Converter; Power electronics; Reliability; Semiconductor Device Relaibility; Switches; Topology; Wind Energy; Wind turbines","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-11-07","","","DC systems, Energy conversion & Storage","","",""
"uuid:53742f37-9217-4d39-a87c-17051a8e8f28","http://resolver.tudelft.nl/uuid:53742f37-9217-4d39-a87c-17051a8e8f28","The Scent of a Smell: An Extensive Comparison between Textual and Structural Smells","Palomba, F. (TU Delft Software Engineering); Panichella, A. (University of Luxembourg); Zaidman, A.E. (TU Delft Software Engineering); Oliveto, Rocco (University of Molise); De Lucia, Andrea (University of Salerno)","","2018","Code smells are symptoms of poor design or implementation choices that have a negative effect on several aspects of software maintenance and evolution, such as program comprehension or change- and fault-proneness. This is why researchers have spent a lot of effort on devising methods that help developers to automatically detect them in source code. Almost all the techniques presented in literature are based on the analysis of structural properties extracted from source code, although alternative sources of information (e.g., textual analysis) for code smell detection have also been recently investigated. Nevertheless, some studies have indicated that code smells detected by existing tools based on the analysis of structural properties are generally ignored (and thus not refactored) by the developers. In this paper, we aim at understanding whether code smells detected using textual analysis are perceived and refactored by developers in the same or different way than code smells detected through structural analysis. To this aim, we set up two different experiments. We have first carried out a software repository mining study to analyze how developers act on textually or structurally detected code smells. Subsequently, we have conducted a user study with industrial developers and quality experts in order to qualitatively analyze how they perceive code smells identified using the two different sources of information. Results indicate that textually detected code smells are easier to identify and for this reason they are considered easier to refactor with respect to code smells detected using structural properties. On the other hand, the latter are often perceived as more severe, but more difficult to exactly identify and remove.","Code Smells; Data mining; Detectors; Empirical Study; Large scale integration; Maintenance engineering; Mining Software Repositories; Software systems; Tools","en","journal article","","","","","","Accepted Author Manuscript","","","","","Software Engineering","","",""
"uuid:01a3730c-0f96-45ca-9800-eb11df492b82","http://resolver.tudelft.nl/uuid:01a3730c-0f96-45ca-9800-eb11df492b82","A design-based vision on future roles in engineering","Klaassen, R.G. (TU Delft Teaching & Learning Services); van Dijk, M.B. (TU Delft Design Aesthetics); Hoope, Roald; Ceulemans, D.S. (TU Delft Project Administration); Kamp, A. (TU Delft Education Management); Jacobs, M.A.F.M. (TU Delft Science Education and Communication); van der Sanden, M.C.A. (TU Delft Science Education and Communication)","Bean, Casey (editor); Bennedsen, Jens (editor); Edström, Kristina (editor); Hugo, Ron (editor); Röslof, Janne (editor); Songer, Robert (editor); Yamamoto, Tomohito (editor)","2018","In this paper, we present a vision on how engineers can play different roles in future society 2030. First we predicted how society in the Netherlands (in relation to Europe and the rest of the world) is going to develop and how future engineers will behave, act and take their position in this future world. We used the ‘Vision in Design’ methodology to unravel the complexity of future society step-by-step and to understand the diversity of engineer(ing)-behaviour: 260 relevant future conditions for 2030 were derived from 10 interviews with visionaries in society, experts in the field of engineering education and from literature search. Clustering these factors into ten driving forces helped us to discover three independent determining dimensions, defining eight possible engineer-behaviours in 2030. As a result of this rich contextual research, these eight roles are further illustrated with accompanying skills and pathways to support role development. The vision and roles have been developed in co-creation and validated in a series of workshops with a wide variety of people within and beyond academia and within the professional world of engineering.","Engineering education; Vision in Design; Engineering Roles; Higher Education; Behaviour; CDIO Standards 1(Context)","en","conference paper","CDIO","","","","","","","","","","Teaching & Learning Services","","",""
"uuid:92d33cac-9374-4bc2-bc09-21a738fb0174","http://resolver.tudelft.nl/uuid:92d33cac-9374-4bc2-bc09-21a738fb0174","Visualizing 17 years of CDIO influence via bibliometric data analysis","Meikleham, Alexandra (University of Calgary); Hugo, Ron (University of Calgary); Kamp, A. (TU Delft Education Management); Malmqvist, Johan (University of Gothenburg)","Bean, Casey (editor); Bennedsen, Jens (editor); Edström, Kristina (editor); Hugo, Ron (editor); Röslof, Janne (editor); Songer, Robert (editor); Yamamoto, Tomohito (editor)","2018","visualizing multi-dimensional indicators of influence in communities of practice (Youtie & Shapira, 2008). Such an approach has been used to map emerging fields of research such as synthetic biology and nanotechnology (Shapira, Kwon, & Youtie, 2017; Youtie & Shapira, 2008). Using this approach, one can track citation and social network data over time to develop a deeper understanding of the influence of the CDIO initiative on engineering education publications since its inception (i.e., the past 17 years). In this paper, bibliometric data analysiswill be used to examine how publications on the CDIO Initiative have evolved. Visualizations are presented using an open-source visualization tool, VOSViewer, and used to understand geographic distribution and co-authorship. A word frequency and co-occurrence analysis has been used to analyze title and abstract data over the same time period. Geographic author network analysis reveals continued growth in regional collaborations over the past seventeen years. Co-authorship by author name reveals a core community of researchers, which has diverged over time into dispersed collaboration groups. Word co-occurrence analysis of title and abstract data from Scopus reveals that design-implement and project-based learning activities have been the central topic of CDIO-related engineering education literature over this time period. An analysis of the terms “faculty competence” and “learning assessment” indicates that these topics are comparatively under-served in the literature, representing fertile research topics for practitioners. The benefit of this research is to provide insight to past development areas and opportunities for growth in the CDIO Initiative.","CDIO framework; Engineering education; technological innovation; product innovation","en","conference paper","CDIO","","","","","","","","","","Education Management","","",""
"uuid:797864cd-050e-4a30-b269-3602f51b579a","http://resolver.tudelft.nl/uuid:797864cd-050e-4a30-b269-3602f51b579a","Morphodynamic impacts of large-scale engineering projects in the Yangtze River delta","Luan, Hualong (East China Normal University; Changjiang River Scientific Research Institute (CRSRI)); Ding, P (East China Normal University); Wang, Zhengbing (TU Delft Coastal Engineering; East China Normal University; Deltares); Yang, S.L. (East China Normal University); Lu, Jin You (Changjiang River Scientific Research Institute (CRSRI))","","2018","Morphodynamics of world's river deltas are increasingly affected by human activities, which are of great ecological, economic and social implications. However, impacts of human interventions in deltaic regions are insufficiently
understood, especially superimposed upon diminishing sediment supplies. This study uses the heavily interfered Yangtze River delta as an example to address this issue. The morphodynamic impacts of the Deepwater Navigation Channel Project (DNCP) during 1997–2013 are investigated through process-based
modeling approach (Delft3D) and bathymetric data analysis. The DNCP was implemented in the mouth bar area of the Yangtze River delta including the twin dikes and 19 groynes with the total length of 132.0 km. Hydrodynamic simulations indicate that the training walls resulted in weaker tidal flow and longer slack period at the East Hengsha Shoal (EHS) and stronger tidal flow at the subaqueous delta. Thus, the EHS is characterized as a sediment accumulation zone after the completion of the training walls. Subsequently, morphological
modeling shows enhanced accretion at the EHS and enhanced erosion at the subaqueous delta when the training walls are taken into account. Numerical experiments further demonstrate that the above changes are mainly attributed to the seaward half of the northern training walls constructed in 2002–2005. This is probably the reason for the observed accretion peak of the EHS in 2002–2007 and the gradual increase in the erosion rate of the subaqueous delta after 2002. The schematized paths of sediment transport after the DNCP indicate that
sediment eroded from the subaqueous delta serves as an important source for accretion of the mouth bar area. It is suggested that siltation promoting projects within the mouth bar area increased shallow shoal accretion and aggravated erosion at the subaqueous delta. With the overall erosion of the Yangtze River delta due to river sediment reduction, large-scale estuarine engineering projects substantially increase the complicacy of its morphodynamic pattern, which merits close attention for sustainable delta management.","Morphodynamics; Estuarine engineering projects; Process-based modeling; Yangtze river delta","en","journal article","","","","","","","","2020-09-03","","","Coastal Engineering","","",""
"uuid:27702436-f7d8-4cc9-ad09-ebb3f9020d01","http://resolver.tudelft.nl/uuid:27702436-f7d8-4cc9-ad09-ebb3f9020d01","The CDIO framework and new perspectives on technological innovation","Smulders, F.E.H.M. (TU Delft OLD Management and Organisation); Kamp, A. (TU Delft Education Management; 4TU.Centre for Engineering Education); Fortin, Clement (Skolkovo Institute of Science and Technology)","Bean, Casey (editor); Bennedsen, Jens (editor); Edström, Kristina (editor); Hugo, Ron (editor); Röslof, Janne (editor); Songer, Robert (editor); Yamamoto, Tomohito (editor)","2018","Technological innovation happens on a daily basis all around us. Yet, in our educational programs there is rarely any attention paid to what this is and how this unfolds over time in real life. This is not at all surprising, since there is not one unified and widely accepted body of knowledge on technological innovation that is grounded enough, meaning, knowledge based on research of technological innovation practice. The CDIO-framework is implicitly addressing innovation from the perspective of existing technological knowledge and therefore is not yet equipped enough for the purpose of tech-innovation. This paper therefore aims to initiate a discussion on what technological innovation is and how this could fit within the CDIO-framework. We will provide a definition of technological innovation based on innovation theoretical framework which reaches its readiness when practice is able to apply the new technology to design, engineer, build, maintain and dispose the objects that apply that particular technology. This lens will be used to analyze a well-documented case that
reports on the development of a new structural aircraft material that is now widely used in the Airbus A380, hence a technological innovation. It will be shown in this paper that the research activities that support the development of the new technology, follow the logic of innovating as a generic and natural phenomenon. The paper ends by proposing a possible path to bring the subject of technological innovation within the confines of our educational curricula, without too much cutting on the subjects that we are teaching. Its base comes from the idea that what we are teaching today is the result of a technological innovation process of yesterday.","CDIO framework; Engineering education; technological innovation; product innovation","en","conference paper","CDIO","","","","","","","","","","OLD Management and Organisation","","",""
"uuid:bec7a8f0-a1eb-47d1-a208-07788b01a140","http://resolver.tudelft.nl/uuid:bec7a8f0-a1eb-47d1-a208-07788b01a140","Propeller-engine interaction in a dynamic model scale environment","Huijgens, L.J.G. (TU Delft Ship Design, Production and Operations); Vrijdag, A. (TU Delft Ship Design, Production and Operations); Hopman, J.J. (TU Delft Ship Design, Production and Operations)","Chung, Jin S. (editor); Hyun, Beom-Soo (editor); Matskevitch, Dmitri (editor); Wang, Alan M. (editor)","2018","Regulatory demands on ship designs, such as emission and manoeuvrability requirements, are becoming increasingly stringent, raising the need for advanced methods to predict and assess dynamic propulsion plant behaviour of a new design. At present, model scale experiments and numerical simulations are not able to predict this behaviour in full detail. To fill the resulting knowledge gap, this paper proposes to further develop existing scale model tests into so-called dynamic model basin tests. These tests aim to predict dynamic behaviour of the ship propulsion plant in complex, dynamic environments in more detail, leading to improved propulsion systems and controls and ultimately, lower emissions, lower fuel consumption and increased manoeuvrability.","ship model; propulsion; propeller-engine interaction; towing tank; model basin; Hardware In the Loop","en","conference paper","International Society of Offshore and Polar Engineers (ISOPE)","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-03-01","","","Ship Design, Production and Operations","","",""
"uuid:e0e9c4e7-79a8-4da2-b34c-c1b31e66a958","http://resolver.tudelft.nl/uuid:e0e9c4e7-79a8-4da2-b34c-c1b31e66a958","A new generation of sloshing pressure sensors","Schreier, S. (TU Delft Ship Hydromechanics and Structures); Poelma, C. (TU Delft Multi Phase Systems)","Chung, Jin S. (editor); Hyun, Beom-Soo (editor); Matskevitch, Dmitri (editor); Wang, Alan M. (editor)","2018","Sloshing impacts are highly dynamic and localized events. One problem in the measurement of sloshing impact pressures is the limited spatial resolution that can be achieved with current sensors. To overcome this hurdle a project was started to develop new sensors that allow to increase the spatial resolution of pressure measurements by a factor 5 compared to current test setups in sloshing experiments. The sensors were based on commercially available MEMS devices, which are suitable for measurements with liquid media. The main application of these devices are static pressure measurements. Therefore a qualification program for the new sensors for sloshing applications was started. First static and dynamic measurements in air gave promising results and encourage to continue this development with future tests in water.","ship model; propulsion; propeller-engine interaction; towing tank; model basin; Hardware In the Loop","en","conference paper","International Society of Offshore and Polar Engineers (ISOPE)","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-01-01","","","Ship Hydromechanics and Structures","","",""
"uuid:5000e635-e70a-42f0-bc8a-b5aefc1ef856","http://resolver.tudelft.nl/uuid:5000e635-e70a-42f0-bc8a-b5aefc1ef856","A condition-based maintenance methodology for rails in regional railway networks using evolutionary multiobjective optimization: Case study line Braşov to Zărneşti in Romania","Nunez, Alfredo (TU Delft Railway Engineering); Jamshidi, A. (TU Delft Railway Engineering); Wang, H. (TU Delft Railway Engineering); Hendriks, J.M. (TU Delft Railway Engineering); Ramirez Fonseca, I. (TU Delft Railway Engineering); Moraal, J. (TU Delft Railway Engineering); Dollevoet, R.P.B.J. (TU Delft Railway Engineering); Li, Z. (TU Delft Railway Engineering)","Vellasco, M. (editor); Estevez, P. (editor); Yen, Gary G. (editor)","2018","In this paper, we propose a methodology based on signal processing and evolutionary multiobjective optimization to facilitate the maintenance decision making of infra-managers in regional railways. Using a train in operation (with passengers onboard), we capture the condition of the rails using Axle Box Acceleration measurements. Then, using Hilbert-Huang Transform, the locations where the major risks are detected and ssessed with a degradation model. Finally,
evolutionary multiobjective optimization is employed to solve the maintenance decision problem, and to facilitate the visualization of the trade-offs between number of interventions and performance. Real-life measurements from the track from Braşov to Zărneşti in Romania are included to show the methodology.","Multiobjective optimization; acceleration measurements; Railway Engineering; ARMOEA; KPIs","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-01-13","","","Railway Engineering","","",""
"uuid:7bae2f3d-1471-4a96-93b8-d75e6d335d62","http://resolver.tudelft.nl/uuid:7bae2f3d-1471-4a96-93b8-d75e6d335d62","Lumen maintenance prediction for LEDs: New insights","Jacobs, B. (Philips Lighting Research); van Driel, W.D. (TU Delft Electronic Components, Technology and Materials; Philips Lighting Research); Schuld, M. (Consultants in Quantitative Methods (CQM))","","2018","Commercial claims for LED-based products in terms of lumen maintenance are fully based on TM-21 extrapolations using LM-80 data. We presented an approach based on statistical data analytics, following the work from Yu & Tseng, at EuroSimE2015. Since then, more LM80 test data came available both for High Power (HP) and Mid Power (MP) LEDs. In this paper, we will present the results of further investigations, where we have taken the work from Meeker into account. This is needed as some commercial claims are based on 10 years of warranty and some service bids provide periods of 20 to 25 years of operation.","Light emitting diodes; Degradation; Mathematical model; Maintenance engineering; Temperature measurement; Life estimation; IEC Standards","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-05-28","","","Electronic Components, Technology and Materials","","",""
"uuid:38b81178-299d-4cd2-8f68-2a1aeab7af19","http://resolver.tudelft.nl/uuid:38b81178-299d-4cd2-8f68-2a1aeab7af19","Testing Autonomous Cars for Feature Interaction Failures using Many-Objective Search","Abdessalem, Raja Ben (University of Luxembourg); Panichella, A. (TU Delft Software Engineering; University of Luxembourg); Nejati, Shiva (University of Luxembourg); Briand, Lionel C. (University of Luxembourg); Stifter, Thomas (IEE S.A.)","","2018","Complex systems such as autonomous cars are typically built as a composition of features that are independent units of functionality. Features tend to interact and impact one another’s behavior in unknown ways. A challenge is to detect and manage feature interactions, in particular, those that violate system requirements, hence leading to failures. In this paper, we propose a technique to detect feature interaction failures by casting this problem into a search-based test generation problem. We define a set of hybrid test objectives (distance functions) that combine traditional coverage-based heuristics with new heuristics specifically aimed at revealing feature interaction failures. We develop a new search-based test generation algorithm, called FITEST, that is guided by our hybrid test objectives. FITEST extends recently proposed many-objective evolutionary algorithms to reduce the time required to compute fitness values. We evaluate our approach using two versions of an industrial self-driving system. Our results show that our hybrid test objectives are able to identify more than twice as many feature interaction failures as two baseline test objectives used in the software testing literature (i.e., coverage-based and failure-based test objectives). Further, the feedback from domain experts indicates that the detected feature interaction failures represent real faults in their systems that were not previously identified based on analysis of the system features and their requirements.","Software testing and debugging; Search-based software engineering; Autonomous Cars; Many-Objective Search","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Software Engineering","","",""
"uuid:764af36d-be50-40c2-9838-704d95b95250","http://resolver.tudelft.nl/uuid:764af36d-be50-40c2-9838-704d95b95250","Enhancing eco-engineering of coastal infrastructure with eco-design: Moving from mitigation to integration","Pioch, S. (CNRS/Université de Montpellier II); Relini, G. (dell'Ambiente e della Vita (DISTAV)); Souche, J. C. (INRA Institut National de La Recherche Agronomique); Stive, M.J.F. (TU Delft Coastal Engineering); De Monbrison, D. (B.R.L. Ingénierie Co.); Nassif, S. (University of New York in Prague); Simard, F. (IUCN Global Marine and Polar Programme); Allemand, D. (Centre Scientifique de Monaco); Saussol, P. (IESE Business School); Spieler, R. (Nova Southeastern University); Kilfoyle, K. (Nova Southeastern University)","","2018","Eco-design aims to enhance eco-engineering practices of coastal infrastructure projects in support of ecological functions before these projects are developed and implemented. The principle is to integrate eco-engineering concepts in the early phases of project design. Although ecological losses are inherent in any construction project, the goal of eco-design is to introduce environmental considerations upfront during technical design choices, and not just afterwards when evaluating the need for reduction or compensatory mitigation. It seeks to reduce the negative impacts of marine infrastructure by introducing a new reflexive civil engineering approach. It requires a valuation of nature with the aim of reducing impacts by incorporating intelligent design and habitat-centered construction. The principle advocated in this paper is to design coastal infrastructures, at micro- to macro-biological scales, using a combination of fine and large scale physical and chemical modifications to hard substrates, within the scope of civil engineering requirements. To this end, we provide a brief introduction to the factors involved in concrete-biota interactions and propose several recommendations as a basis to integrate ecology into civil engineering projects, specifically addressed to concrete.","Coastal civil engineering; Eco-design; Eco-engineering; Ecological integration; Ecological restoration; Environmental impact assessment","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-12-06","","","Coastal Engineering","","",""
"uuid:7f2b9ac4-8390-4c78-b327-4de830111087","http://resolver.tudelft.nl/uuid:7f2b9ac4-8390-4c78-b327-4de830111087","Bone tissue engineering via growth factor delivery: from scaffolds to complex matrices","De Witte, Tinke (Student TU Delft; The University of Texas at Austin); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Peppas, Nicholas (The University of Texas at Austin)","","2018","In recent years, bone tissue engineering has emerged as a promising solution to the limitations of current gold standard treatment options for bone related-disorders such as bone grafts. Bone tissue engineering provides a scaffold design that mimics the extracellular matrix, providing an architecture that guides the natural bone regeneration process. During this period, a new generation of bone tissue engineering scaffolds has been designed and characterized that explores the incorporation of signaling molecules in order to enhance cell recruitment and ingress into the scaffold, as well as osteogenic differentiation and angiogenesis, each of which is crucial to successful bone regeneration. Here, we outline and critically analyze key characteristics of successful bone tissue engineering scaffolds. We also explore candidate materials used to fabricate these scaffolds. Different growth factors involved in the highly coordinated process of bone repair are discussed, and the key requirements of a growth factor delivery system are described. Finally, we concentrate on an analysis of scaffold-based growth factor delivery strategies found in the recent literature. In particular, the incorporation of two-phase systems consisting of growth factor-loaded nanoparticles embedded into scaffolds shows great promise, both by providing sustained release over a therapeutically relevant timeframe and the potential to sequentially deliver multiple growth factors.","scaffolds; bone growth; tissue engineering; growth factor delivery","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:4bc8187a-519e-4692-a245-da42dc8199d7","http://resolver.tudelft.nl/uuid:4bc8187a-519e-4692-a245-da42dc8199d7","Laboratory evolution of a glucose-phosphorylation-deficient, arabinose-fermenting S. cerevisiae strain reveals mutations in GAL2 that enable glucose-insensitive l-arabinose uptake","Verhoeven, M.D. (TU Delft BT/Industriele Microbiologie); Bracher, J.M. (TU Delft BT/Industriele Microbiologie); Nijland, Jeroen G. (Rijksuniversiteit Groningen); Bouwknegt, J. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Driessen, Arnold J.M. (Rijksuniversiteit Groningen)","","2018","Cas9-assisted genome editing was used to construct an engineered glucose-phosphorylation-negative S. cerevisiae strain, expressing the Lactobacillus plantaruml-arabinose pathway and the Penicillium chrysogenum transporter PcAraT. This strain, which showed a growth rate of 0.26 h−1 on l-arabinose in aerobic batch cultures, was subsequently evolved for anaerobic growth on l-arabinose in the presence of d-glucose and d-xylose. In four strains isolated from two independent evolution experiments the galactose-transporter gene GAL2 had been duplicated, with all alleles encoding Gal2N376T or Gal2N376I substitutions. In one strain, a single GAL2 allele additionally encoded a Gal2T89I substitution, which was subsequently also detected in the independently evolved strain IMS0010. In 14C-sugar-transport assays, Gal2N376S, Gal2N376T and Gal2N376I substitutions showed a much lower glucose sensitivity of l-arabinose transport and a much higher Km for d-glucose transport than wild-type Gal2. Introduction of the Gal2N376I substitution in a non-evolved strain enabled growth on l-arabinose in the presence of d-glucose. Gal2N376T, T89I and Gal2T89I variants showed a lower Km for l-arabinose and a higher Km for d-glucose than wild-type Gal2, while reverting Gal2N376T, T89I to Gal2N376 in an evolved strain negatively affected anaerobic growth on l-arabinose. This study indicates that optimal conversion of mixed-sugar feedstocks may require complex ‘transporter landscapes’, consisting of sugar transporters with complementary kinetic and regulatory properties.","yeast; pentose fermentation; l-arabinose; transporter engineering; laboratory evolution; bioethanol; gene duplication","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:bc4c39d6-3c8b-437a-8709-eb3b9a47170b","http://resolver.tudelft.nl/uuid:bc4c39d6-3c8b-437a-8709-eb3b9a47170b","Laboratory evolution for forced glucose-xylose co-consumption enables identification of mutations that improve mixed-sugar fermentation by xylose-fermenting Saccharomyces cerevisiae","Papapetridis, I. (TU Delft BT/Industriele Microbiologie); Verhoeven, M.D. (TU Delft BT/Industriele Microbiologie); Wiersma, S.J. (TU Delft BT/Industriele Microbiologie); Goudriaan, M.; van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie)","","2018","Simultaneous fermentation of glucose and xylose can contribute to improved productivity and robustness of yeast-based processes for bioethanol production from lignocellulosic hydrolysates. This study explores a novel laboratory evolution strategy for identifying mutations that contribute to simultaneous utilisation of these sugars in batch cultures of Saccharomyces cerevisiae. To force simultaneous utilisation of xylose and glucose, the genes encoding glucose-6-phosphate isomerase (PGI1) and ribulose-5-phosphate epimerase (RPE1) were deleted in a xylose-isomerase-based xylose-fermenting strain with a modified oxidative pentose-phosphate pathway. Laboratory evolution of this strain in serial batch cultures on glucose–xylose mixtures yielded mutants that rapidly co-consumed the two sugars. Whole-genome sequencing of evolved strains identified mutations in HXK2, RSP5 and GAL83, whose introduction into a non-evolved xylose-fermenting S. cerevisiae strain improved co-consumption of xylose and glucose under aerobic and anaerobic conditions. Combined deletion of HXK2 and introduction of a GAL83G673T allele yielded a strain with a 2.5-fold higher xylose and glucose co-consumption ratio than its xylose-fermenting parental strain. These two modifications decreased the time required for full sugar conversion in anaerobic bioreactor batch cultures, grown on 20 g L−1 glucose and 10 g L−1 xylose, by over 24 h. This study demonstrates that laboratory evolution and genome resequencing of microbial strains engineered for forced co-consumption is a powerful approach for studying and improving simultaneous conversion of mixed substrates.","biofuels; yeast; industrial biotechnology; Redox engineering; fermentation; pentoses","en","journal article","","","","","","","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:4d6512c4-3a2c-4095-b941-913e73df2497","http://resolver.tudelft.nl/uuid:4d6512c4-3a2c-4095-b941-913e73df2497","Fermentation of glucose-xylose-arabinose mixtures by a synthetic consortium of single-sugar-fermenting Saccharomyces cerevisiae strains","Verhoeven, M.D. (TU Delft BT/Industriele Microbiologie); de Valk, S.C. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Biotechnologie)","","2018","D-Glucose, D-xylose and L-arabinose are major sugars in lignocellulosic hydrolysates. This study explores fermentation of glucose-xylose-arabinose mixtures by a consortium of three ‘specialist’ Saccharomyces cerevisiae strains. A D-glucose- and L-arabinose-tolerant xylose specialist was constructed by eliminating hexose phosphorylation in an engineered xylose-fermenting strain and subsequent laboratory evolution. A resulting strain anaerobically grew and fermented D-xylose in the presence of 20 g L-1 of D-glucose and L-arabinose. A synthetic consortium that additionally comprised a similarly obtained arabinose specialist and a pentose-non-fermenting laboratory strain, rapidly and simultaneously converted D-glucose and L-arabinose in anaerobic batch cultures on three-sugar mixtures. However, performance of the xylose specialist was strongly impaired in these mixed cultures. After prolonged cultivation of the consortium on three-sugar mixtures, the time required for complete sugar conversion approached that of a previously constructed and evolved ‘generalist’ strain. In contrast to the generalist strain, whose fermentation kinetics deteriorated during prolonged repeated-batch cultivation on a mixture of 20 g L-1 D-glucose, 10 g L-1 D-xylose and 5 g L-1 L-arabinose, the evolved consortium showed stable fermentation kinetics. Understanding the interactions between specialist strains is a key challenge in further exploring the applicability of this synthetic consortium approach for industrial fermentation of lignocellulosic hydrolysates.","bioethanol; mixed-culture fermentationt; evolutionary engineering; pentose fermentation; Yeast","en","journal article","","","","","","Accepted Author Manuscript","","","","BT/Biotechnologie","BT/Industriele Microbiologie","","",""
"uuid:d8b594fe-f6d8-412a-83b7-cba8870f6cc9","http://resolver.tudelft.nl/uuid:d8b594fe-f6d8-412a-83b7-cba8870f6cc9","An Exploratory Study on Faults in Web API Integration in a Large-Scale Payment Company","Aué, J. (Adyen B.V.); Aniche, Maurício (TU Delft Software Engineering); Lobbezoo, Maikel (Adyen B.V.); van Deursen, A. (TU Delft Software Technology)","","2018","Service-oriented architectures are more popular than ever, and increasingly companies and organizations depend on services offered through Web APIs. The capabilities and complexity of Web APIs differ from service to service, and therefore the impact of API errors varies. API problem cases related to Adyen's payment service were found to have direct considerable impact on API consumer applications. With more than 60,000 daily API errors, the potential impact is enormous. In an effort to reduce the impact of API related problems, we analyze 2.43 million API error responses to identify the underlying faults. We quantify the occurrence of faults in terms of the frequency and impacted API consumers. We also challenge our quantitative results by means of a survey with 40 API consumers. Our results show that 1) faults in API integration can be grouped into 11 general causes: invalid user input, missing user input, expired request data, invalid request data, missing request data, insufficient permissions, double processing, configuration, missing server data, internal and third party, 2) most faults can be attributed to the invalid or missing request data, and most API consumers seem to be impacted by faults caused by invalid request data and third party integration; and 3) insufficient guidance on certain aspects of the integration and on how to recover from errors is an important challenge to developers.","web engineering; web API integration; webservices","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:f83c0000-e209-48ff-9673-e8edeaf900cf","http://resolver.tudelft.nl/uuid:f83c0000-e209-48ff-9673-e8edeaf900cf","On the accuracy of automated shoreline detection derived from satellite imagery: A case study of the Sand Motor mega-scale nourishment","Hagenaars, Gerben (Deltares); de Vries, S. (TU Delft Coastal Engineering); Luijendijk, Arjen (TU Delft Coastal Engineering; Deltares); de Boer, W.P. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Deltares); Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics)","","2018","Measured trends and variability in shoreline position are used by coastal managers, scientists and engineers to understand and monitor coastal systems. This paper presents a new and generic method for automated shoreline detection from the largely unexplored collection of publicly available satellite imagery. The position of the obtained Satellite Derived Shoreline (SDS) is tested for accuracy for 143 images against high resolution in-situ data along a coastal stretch near the Sand Motor, a well-documented mega-scale nourishment along the Dutch coast. In this assessment, we quantify the effects of potential inaccuracy drivers such as the presence of clouds and wave-induced foam. The overall aim of this study is to verify whether the SDS is suitable to study structural coastline trends for coastal engineering practice.
In the ideal case of a cloud free satellite image without the presence of waves, with limited morphological changes between the time of image acquisition and the date of the in-situ measurement, the accuracy of the SDS is with subpixel precision (smaller than 10–30 m, depending on the satellite mission) and depends on intertidal beach slope and image pixel resolution. For the highest resolution images we find an average offset of 1 m between the SDS position and the in-situ shoreline in the considered domain. The accuracy deteriorates in the presence of clouds and/or waves on the image, satellite sensor corrections and georeferencing errors. The case study showed that especially the presence of clouds can lead to a considerable seaward offset of the SDS of multiple pixels (e.g. order 200 m). Wave-induced foam results in seaward offsets in the order of 40 m.
These effects can largely be overcome by creating composite images, which results in a continuous dataset with subpixel precision (10–30 m, depending on the satellite mission). This implies that structural trends can be detected for coastlines that have changed with at least the pixel resolution within the considered timespan.
Given the accuracy of composite images along the Sand Motor in combination with the worldwide availability of public satellite imagery covering the last decades, this technique can potentially be applied at other locations with large (structural) coastline trends.
In this study, we first replicate previous research on method- level bug prediction on different systems/timespans. Afterwards, we reflect on the evaluation strategy and propose a more realistic one. Key results of our study show that the performance of the method-level bug prediction model is similar to what previously reported also for different systems/timespans, when evaluated with the same strategy. However—when evaluated with a more realistic strategy—all the models show a dramatic drop in performance exhibiting results close to that of a random classifier. Our replication and negative results indicate that method-level bug prediction is still an open challenge.","empirical software engineering; bug prediction; replication; negative results","en","conference paper","IEEE","","","","","","","","","","Software Engineering","","",""
"uuid:1072ecd5-2d36-4ce2-935b-4141daccd345","http://resolver.tudelft.nl/uuid:1072ecd5-2d36-4ce2-935b-4141daccd345","Mesoscopic physical removal of material using sliding nano-diamond contacts","Celano, Umberto (IMEC-Solliance); Hsia, Feng Chun (IMEC-Solliance; National Cheng Kung University); Vanhaeren, Danielle (IMEC-Solliance); Paredis, Kristof (IMEC-Solliance); Nordling, Torbjörn E.M. (National Cheng Kung University); Buijnsters, J.G. (TU Delft Micro and Nano Engineering); Hantschel, Thomas (IMEC-Solliance); Vandervorst, Wilfried (IMEC-Solliance; Katholieke Universiteit Leuven)","","2018","Wear mechanisms including fracture and plastic deformation at the nanoscale are central to understand sliding contacts. Recently, the combination of tip-induced material erosion with the sensing capability of secondary imaging modes of AFM, has enabled a slice-and-view tomographic technique named AFM tomography or Scalpel SPM. However, the elusive laws governing nanoscale wear and the large quantity of atoms involved in the tip-sample contact, require a dedicated mesoscale description to understand and model the tip-induced material removal. Here, we study nanosized sliding contacts made of diamond in the regime whereby thousands of nm3 are removed. We explore the fundamentals of high-pressure tip-induced material removal for various materials. Changes in the load force are systematically combined with AFM and SEM to increase the understanding and the process controllability. The nonlinear variation of the removal rate with the load force is interpreted as a combination of two contact regimes each dominating in a particular force range. By using the gradual transition between the two regimes, (1) the experimental rate of material eroded on each tip passage is modeled, (2) a controllable removal rate below 5 nm/scan for all the materials is demonstrated, thus opening to future development of 3D tomographic AFM.","Characterization and analytical techniques; Electrical and electronic engineering","en","journal article","","","","","","","","","","","Micro and Nano Engineering","","",""
"uuid:22797037-9127-4926-9fe0-2af9d8a68dfb","http://resolver.tudelft.nl/uuid:22797037-9127-4926-9fe0-2af9d8a68dfb","Performance assessment of a multi-fuel hybrid engine for future aircraft","Yin, F. (TU Delft Aircraft Noise and Climate Effects); Gangoli Rao, A. (TU Delft Flight Performance and Propulsion); Bhat, Abhishek (Honeywell International Inc.); Chen, Min (Beihang University)","","2018","This paper presents the performance assessment of a novel turbofan engine using two energy sources: Liquid Natural Gas (LNG) and kerosene, called Multi-Fuel Hybrid Engine (MFHE). The MFHE is a new engine concept consisting of several novel features, such as a contra-rotating fan to sustain distortion caused by boundary layer ingestion, a sequential dual-combustion system to facilitate “Energy Mix” in aviation and a Cryogenic Bleed Air Cooling System (CBACS) to cool the turbine cooling air. The MFHE has been envisaged as a propulsion system for a long-range Multi-Fuel Blended Wing Body (MFBWB) aircraft. In this research, we study the uninstalled characteristics of the MFHE covering three aspects: 1) the effects of CBACS on the High Pressure Turbine (HPT) cooling air requirement and its consequence on the engine cycle efficiency; 2) the cycle optimization of the MFHE; 3) the performance of the MFHE at a mission level. An integrated model framework consisting of an engine performance model, a sophisticated turbine-cooling model, and a CBACS model is used. The parametric analysis shows that using CBACS can reduce the bleed air temperature significantly (up to 400 K), thereby decreasing the HPT cooling air by more than 40%. Simultaneously, the LNG temperature increases by more than 200 K. The hybrid engine alone reduces the CO2 emission by about 27% and the energy consumption by 12% compared to the current state-of-the-art turbofan engine. Furthermore, the mission analysis indicates a reduction in NOx emission by 80% and CO2 emission by 50% when compared to the baseline aircraft B-777 200ER.
human interventions in these areas aim to prevent the lowlands from drowning.
This booklet shows the process and results of aeolis-gap the border developed during the elective course Landscape Architecture ON Site, offered by TU Delft MSc Landscape Architecture. As part of the research program related to coastal defence, the group developed an architectural intervention in the dune landscape to accelerate the growth of dunes.
The Wadden islands have been barrier islands for the Netherlands for hundreds of years but due to the rising sea level they are under great pressure. Therefore, the Oerol Festival at Terschelling is a great platform to experiment and understand this concept and interweaving it with art. Landscape, art and science come together in this project. The design process is based on experiences of the place, experiments, prototyping results of theoretical and landscape studies, workshops and brainstorm sessions.","oerol; Design Exploration; Dune growth; curation; Landscape Architecture; Coastal Engineering","en","book","TU Delft, Landscape Architecture","","","","","","","","","","Landscape Architecture","","",""
"uuid:eb4aa829-f855-48d3-8ee4-9909e72356b8","http://resolver.tudelft.nl/uuid:eb4aa829-f855-48d3-8ee4-9909e72356b8","2-Deoxy-d-ribose-5-phosphate aldolase (DERA): applications and modifications","Haridas, M. (TU Delft ChemE/Product and Process Engineering); Abdelraheem, E.M.M. (TU Delft BT/Biocatalysis; Sohag University); Hanefeld, U. (TU Delft BT/Biotechnologie)","","2018","© 2018, The Author(s). 2-Deoxy-d-ribose-5-phosphate aldolase (DERA) is a class I aldolase that offers access to several building blocks for organic synthesis. It catalyzes the stereoselective C–C bond formation between acetaldehyde and numerous other aldehydes. However, the practical application of DERA as a biocatalyst is limited by its poor tolerance towards industrially relevant concentrations of aldehydes, in particular acetaldehyde. Therefore, the development of proper experimental conditions, including protein engineering and/or immobilization on appropriate supports, is required. The present review is aimed to provide a brief overview of DERA, its history, and progress made in understanding the functioning of the enzyme. Furthermore, the current understanding regarding aldehyde resistance of DERA and the various optimizations carried out to modify this property are discussed.","Aldol reaction; Aldolase; C–C bond; DERA; Immobilization; Protein engineering","en","journal article","","","","","","","","","","BT/Biotechnologie","ChemE/Product and Process Engineering","","",""
"uuid:a653e382-3be1-465a-84e3-5415a7967464","http://resolver.tudelft.nl/uuid:a653e382-3be1-465a-84e3-5415a7967464","Mock objects for testing java systems: Why and how developers use them, and how they evolve","Spadini, D. (TU Delft Software Engineering; Software Improvement Group); Aniche, Maurício (TU Delft Software Engineering); Bruntink, Magiel (Software Improvement Group); Bacchelli, A. (University of Zürich)","","2018","When testing software artifacts that have several dependencies, one has the possibility of either instantiating these dependencies or using mock objects to simulate the dependencies’ expected behavior. Even though recent quantitative studies showed that mock objects are widely used both in open source and proprietary projects, scientific knowledge is still lacking on how and why practitioners use mocks. An empirical understanding of the situations where developers have (and have not) been applying mocks, as well as the impact of such decisions in terms of coupling and software evolution can be used to help practitioners adapt and improve their future usage. To this aim, we study the usage of mock objects in three OSS projects and one industrial system. More specifically, we manually analyze more than 2,000 mock usages. We then discuss our findings with developers from these systems, and identify practices, rationales, and challenges. These results are supported by a structured survey with more than 100 professionals. Finally, we manually analyze how the usage of mock objects in test code evolve over time as well as the impact of their usage on the coupling between test and production code. Our study reveals that the usage of mocks is highly dependent on the responsibility and the architectural concern of the class. Developers report to frequently mock dependencies that make testing difficult (e.g., infrastructure-related dependencies) and to not mock classes that encapsulate domain concepts/rules of the system. Among the key challenges, developers report that maintaining the behavior of the mock compatible with the behavior of original class is hard and that mocking increases the coupling between the test and the production code. Their perceptions are confirmed by our data, as we observed that mocks mostly exist since the very first version of the test class, and that they tend to stay there for its whole lifetime, and that changes in production code often force the test code to also change.","Software testing; Mocking practices; Mockito; Empirical Software Engineering","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:43d98112-660b-45f7-96e6-194f493e12db","http://resolver.tudelft.nl/uuid:43d98112-660b-45f7-96e6-194f493e12db","Active learning in redesigning mathematics courses for engineering students","Cabo, A.J. (TU Delft Statistics; 4TU.Centre for Engineering Education); Klaassen, R.G. (TU Delft Teaching & Learning Services; 4TU.Centre for Engineering Education)","Bean, Casey (editor); Bennedsen, Jens (editor); Edström, Kristina (editor); Hugo, Ron (editor); Röslof, Janne (editor); Songer, Robert (editor); Yamamoto, Tomohito (editor)","2018","“Prepare, Participate, Practice”: active learning in designing basic maths courses for engineering students at TU Delft works! The PRoject Innovation Mathematics Education (PRIME) at Delft University of Technology (TU Delft) is all about redesigning mathematics courses for engineers. This paper describes the process of developing, implementing, evaluating and implementing again of three basic courses at TU Delft using a blended learning approach developed by a growing team of teachers from the mathematics department. Our findings suggest that the approach taken enhances students’ learning performance in maths education. The main results show that students have a more active learning experience compared to the traditional setup of these courses, leading to more engagement, more interaction and better results. An important role is played by meaningful examples taken from the engineering faculty where the students are studying, showing students from that faculty what role the mathematics play in their field of interest. This is also used to develop their skills in mathematical modelling.","Engineering education; blended learning; mathematics; team-based development; active learning; CDIO- Standards: 1, 2, 8, 9, 10, 11, 12","en","conference paper","CDIO","","","","","","","","","","Statistics","","",""
"uuid:3a20412c-0592-4831-942b-53d60b9ffc88","http://resolver.tudelft.nl/uuid:3a20412c-0592-4831-942b-53d60b9ffc88","轨道不平顺概率模型","Xu, L. (TU Delft Railway Engineering; Southwest Jiaotong University); Zhai, Wan Ming (Southwest Jiaotong University)","","2018","To efficiently select track irregularity random samples for satisfying the ergodicity requirements of excitation sources in stochastic dynamics and reliability analysis in vehicle-track system, the weak-stationarity and similarity spectral of track irregularities were introduced to propose a track irregularity probabilistic model. Using the discrete probability integration and statistical approaches, the massively measured track irregularity time histories were divided into multiple time-domain sequences. The statistical power spectral density distribution of each sequence was calculated by the spectral analysis method. Then, using the matrix-based method, the set representation of the power spectral density function of track irregularities was obtained. It was assumed that the power spectral densities could be linearly accumulated at different frequencies, allowing the probabilities of entire spectra line to be obtained using the power spectral density probability distribution of a single frequency. The representative track irregularity spectra were selected through the commonly random simulation methods, and the track random irregularities were inversely simulated. The height and direction track irregularities of high-speed railway about 269 km were measured. Based on the vehicle-track coupled dynamics theory, the calculation results between the track irregularity probabilistic model and track irregularity stochastic model was compared from the aspects of the simulated amplitude of track irregularity and the probability density distribution for dynamic response in the vehicle-track system to verify the validity and high efficacy of the track irregularity probabilistic model. Calculation result shows that when taking the track random irregularities caused by the two models as excitation sources, the difference of the obtained probability entropies of vehicle-track system dynamic response between the two models is less than 2%. Both models can accurately express the excitation characteristics of track irregularities. The stochastic and probabilistic models need 131 and 33 random samples, respectively, to guarantee the consistent probability density distributions between the simulation and measurement, and the probabilistic model has higher computation efficiency. Under the presented computational condition, the wheel-rail forces and car body accelerations are 38-152 kN and -0.042g-0.043g, respectively, and are respectively less than the limits of wheel-rail forces (170 kN) and car body accelerations (0.25g) in Code for High Speed Railway Design (TB 10621-2014). The track irregularity status of the investigated high-speed line is sufficient to guarantee the running safety and riding comfort of the vehicle.","Probabilistic model; Railway engineering; Random vibration; Stochastic model; Track irregularity; Vehicle-track coupled dynamics","zh","journal article","","","","","","","","","","","Railway Engineering","","",""
"uuid:f3f8bf94-63ce-4318-967c-23f17eb6cfc9","http://resolver.tudelft.nl/uuid:f3f8bf94-63ce-4318-967c-23f17eb6cfc9","Pilot study boot camp: professional engineering roles experienced in a week","Leandro Cruz, M. (TU Delft Novel Aerospace Materials); Saunders-Smits, Gillian (TU Delft Aerospace Structures & Materials)","","2018","Engineering education has recognised that engineering graduates require transversal competencies like communication, teamwork and problem-solving alongside technical competencies. The importance of transversal competencies has grown and curriculum elements have been implemented to stimulate these competencies. However, a gap still exists between what education provides and practice requires. To reduce this gap and increase engineering student’s employability, lecturers need to expose students to transversal competencies and allow them to practice them throughout the curriculum. For the purpose to stimulate the development of students’ transversal competencies necessary to engineering careers, a week-long style boot camp course was designed and implemented at the Delft University of Technology. In this study, a pre and post-questionnaire and a reflection were administered to students to evaluate the transversal competencies encountered and acquired by the students during the course, their engineering role awareness and course efficacy. Findings revealed that students improve in their transversal competencies including presentation skills, interdisciplinary thinking, innovation and creativity, and professional engineering role knowledge during the course. However, improvements in the attracting of students to the course and specification of the assignment need to be addressed for the next run of this course scheduled for next year. Lecturers are encouraged to implement authentic learning experiences like this, as these experiences provide students with awareness and practice of the engineering roles and stimulate students’ transversal competency development necessary to be successful in those roles.","One-week course; Boot camp; Professional Engineering Roles; Pilot Study; Transversal Competencies","en","conference paper","","","","","","","","","","Aerospace Structures & Materials","Novel Aerospace Materials","","",""
"uuid:4d89db6e-d617-49c0-aa26-506b905632b3","http://resolver.tudelft.nl/uuid:4d89db6e-d617-49c0-aa26-506b905632b3","Designing context-aware systems: A method for understanding and analysing context in practice","van Engelenburg, S.H. (TU Delft Information and Communication Technology); Janssen, M.F.W.H.A. (TU Delft Information and Communication Technology); Klievink, A.J. (TU Delft Organisation & Governance)","","2018","Context-aware systems are systems that have the ability to sense and adapt to the environment. To operate in large-scale multi-stakeholder environments, systems often require context awareness. The context elements that systems in such environments should take into account are becoming ever more complex and go beyond elements like geographic location. In addition, these environments are themselves so complex that it is hard to determine what parts of them belong to the relevant context of a context-aware system. However, insight into what belongs to this context is needed to establish what the design of a context-aware system should be to meet its goal. The ambiguity of what belongs to context in these complex organizational environments causes the design process to become either inefficient or less effective. In this paper, we provide a method to identify what elements of the environment are relevant context and to then base the design on this insight. The proposed method consists of three steps: 1) getting insight into context, 2) determining what components are needed to sense and adapt to context, and 3) determining the rules for how the system should adapt in different situations. To reduce ambiguity by organizations, the method requires a more specified definition of context than the ones in current literature, which we also provide in this paper. In addition to reducing ambiguity, the highly structured way in which the components and rules are derived from insight into context provides a way to further deal with the high complexity of the context. The method was applied for the development of a context-aware system for business-to-government (B2G) information sharing in the container shipping domain. Information sharing in this domain is highly complex, as legislation, many stakeholders, and a mix of cooperation and competition result in a highly complex environment. The development of this B2G information sharing system thus provides an example of how the method can be used to develop a context-aware system in a highly complex environment.","Context; Context Awareness; Context elements; Design; Requirements Engineering; Business-to-government information sharing","en","journal article","","","","","","","","","","","Information and Communication Technology","","",""
"uuid:7e2f0498-f4e3-49e3-8c91-23c0118a3f1b","http://resolver.tudelft.nl/uuid:7e2f0498-f4e3-49e3-8c91-23c0118a3f1b","Can disc diffusion susceptibility tests assess the antimicrobial activity of engineered nanoparticles?","Kourmouli, A. (TU Delft ChemE/Materials for Energy Conversion and Storage; University of the Aegean); Valenti, M. (TU Delft ChemE/Materials for Energy Conversion and Storage); van Rijn, E. (TU Delft RID/KEWO/Stralingsbeschermingseenheid; Kavli institute of nanoscience Delft); Beaumont, H.J.E. (TU Delft BN/Bertus Beaumont Lab; Kavli institute of nanoscience Delft); Kalantzi, Olga Ioanna (University of the Aegean); Schmidt-Ott, A. (TU Delft ChemE/Materials for Energy Conversion and Storage); Biskos, G. (TU Delft Atmospheric Remote Sensing; TU Delft Energie and Industrie; The Cyprus Institute)","","2018","The use of disc diffusion susceptibility tests to determine the antibacterial activity of engineered nanoparticles (ENPs) is questionable because their low diffusivity practically prevents them from penetrating through the culture media. In this study, we investigate the ability of such a test, namely the Kirby-Bauer disc diffusion test, to determine the antimicrobial activity of Au and Ag ENPs having diameters from 10 to 40 nm on Escherichia coli cultures. As anticipated, the tests did not show any antibacterial effects of Au nanoparticles (NPs) as a result of their negligible diffusivity through the culture media. Ag NPs on the other hand exhibited a strong antimicrobial activity that was independent of their size. Considering that Ag, in contrast to Au, dissolves upon oxidation and dilution in aqueous solutions, the apparent antibacterial behavior of Ag NPs is attributed to the ions they release. The Kirby-Bauer method, and other similar tests, can therefore be employed to probe the antimicrobial activity of ENPs related to their ability to release ions rather than to their unique size-dependent properties. [Figure not available: see fulltext.].","Aerosol-based nanoparticle synthesis; Antimicrobial activity; Disc diffusion method; Engineered nanoparticles; Gold nanoparticles; Silver nanoparticles","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:5d8eca55-fd54-4a14-8be2-7f95c3c26fdd","http://resolver.tudelft.nl/uuid:5d8eca55-fd54-4a14-8be2-7f95c3c26fdd","Varieties of responsibility: two problems of responsible innovation","van de Poel, I.R. (TU Delft Values Technology and Innovation); Sand, M. (TU Delft Ethics & Philosophy of Technology)","","2018","The notion of responsible innovation suggests that innovators carry additional responsibilities (to society, stakeholders, users) beyond those commonly suggested. In this paper, we will discuss the meaning of these novel responsibilities focusing on two philosophical problems of attributing such responsibilities to innovators. The first is the allocation of responsibilities to innovators. Innovation is a process that involves a multiplicity of agents and unpredictable, far-reaching causal chains from innovation to social impacts, which creates great uncertainty. A second problem is constituted by possible trade-offs between different kinds of responsibility. It is evident that attributing backward-looking responsibility for product failures diminishes the willingness to learn about such defects and to take forward-looking responsibility. We will argue that these problems can be overcome by elaborating what it is exactly that innovators are responsible for. In this manner, we will distinguish more clearly between holding responsible and taking responsibility. This opens a space for ‘supererogatory’ responsibilities. Second, we will argue that both innovation processes and outcomes can be objects of innovators’ responsibility. Third, we will analyze different kinds of responsibility (blameworthiness, accountability, liability, obligation and virtue) and show that the functions of their attribution are not necessarily contradictory. Based on this conceptual refinement, we will argue that accountability, responsibility-as-virtue and the willingness to take responsibility are crucial for responsible innovation.","Accountability; Engineering; Ethics; Responsibility; Responsible innovation; Technology; Virtue","en","journal article","","","","","","","","","","Values Technology and Innovation","Ethics & Philosophy of Technology","","",""
"uuid:50a18940-f444-4b67-8214-3c434e3aca33","http://resolver.tudelft.nl/uuid:50a18940-f444-4b67-8214-3c434e3aca33","Multi-component vapor-liquid equilibrium model for LES of high-pressure fuel injection and application to ECN Spray A","Matheis, Jan (Technische Universität München); Hickel, S. (TU Delft Aerodynamics)","","2018","We present and evaluate a two-phase model for Eulerian large-eddy simulations (LES) of liquid-fuel injection and mixing at high pressure. The model is based on cubic equations of state and vapor-liquid equilibrium calculations and can represent the coexistence of supercritical states and multi-component subcritical two-phase states via a homogeneous mixture approach. Well-resolved LES results for the Spray A benchmark case of the Engine Combustion Network (ECN) and three additional operating conditions are found to agree very well with available experimental data. We also address well-known numerical challenges of trans- and supercritical fluid mixing and compare a fully conservative formulation to a quasi-conservative formulation of the governing equations. Our results prove physical and numerical consistency of both methods on fine grids and demonstrate the effects of energy conservation errors associated with the quasi-conservative formulation on typical LES grids.","Diesel fuel injection; Engine Combustion Network (ECN) Spray A; Large Eddy Simulation (LES); Supercritical; Transcritical; Vapor-liquid equilibrium (VLE)","en","journal article","","","","","","","","","","","Aerodynamics","","",""
"uuid:113d8e73-d8f4-4825-92f0-6950a582af0b","http://resolver.tudelft.nl/uuid:113d8e73-d8f4-4825-92f0-6950a582af0b","The Penicillium chrysogenum transporter PcAraT enables high-affinity, glucose-insensitive l-arabinose transport in Saccharomyces cerevisiae","Bracher, J.M. (TU Delft BT/Industriele Microbiologie); Verhoeven, M.D. (TU Delft BT/Industriele Microbiologie); Wisselink, H. Wouter (Isobionics); Crimi, B. (TU Delft BT/Industriele Microbiologie; UMR9002-CNRS-UM); Nijland, Jeroen G. (Rijksuniversiteit Groningen); Driessen, Arnold J.M. (Rijksuniversiteit Groningen); Klaassen, Paul (DSM); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie; AlbaNova University Center); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Industriele Microbiologie)","","2018","Background: l-Arabinose occurs at economically relevant levels in lignocellulosic hydrolysates. Its low-affinity uptake via the Saccharomyces cerevisiae Gal2 galactose transporter is inhibited by d-glucose. Especially at low concentrations of l-arabinose, uptake is an important rate-controlling step in the complete conversion of these feedstocks by engineered pentose-metabolizing S. cerevisiae strains. Results: Chemostat-based transcriptome analysis yielded 16 putative sugar transporter genes in the filamentous fungus Penicillium chrysogenum whose transcript levels were at least threefold higher in l-arabinose-limited cultures than in d-glucose-limited and ethanol-limited cultures. Of five genes, that encoded putative transport proteins and showed an over 30-fold higher transcript level in l-arabinose-grown cultures compared to d-glucose-grown cultures, only one (Pc20g01790) restored growth on l-arabinose upon expression in an engineered l-arabinose-fermenting S. cerevisiae strain in which the endogenous l-arabinose transporter, GAL2, had been deleted. Sugar transport assays indicated that this fungal transporter, designated as PcAraT, is a high-affinity (K m = 0.13 mM), high-specificity l-arabinose-proton symporter that does not transport d-xylose or d-glucose. An l-arabinose-metabolizing S. cerevisiae strain in which GAL2 was replaced by PcaraT showed 450-fold lower residual substrate concentrations in l-arabinose-limited chemostat cultures than a congenic strain in which l-arabinose import depended on Gal2 (4.2 × 10-3 and 1.8 g L-1, respectively). Inhibition of l-arabinose transport by the most abundant sugars in hydrolysates, d-glucose and d-xylose was far less pronounced than observed with Gal2. Expression of PcAraT in a hexose-phosphorylation-deficient, l-arabinose-metabolizing S. cerevisiae strain enabled growth in media supplemented with both 20 g L-1 l-arabinose and 20 g L-1 d-glucose, which completely inhibited growth of a congenic strain in the same condition that depended on l-arabinose transport via Gal2. Conclusion: Its high affinity and specificity for l-arabinose, combined with limited sensitivity to inhibition by d-glucose and d-xylose, make PcAraT a valuable transporter for application in metabolic engineering strategies aimed at engineering S. cerevisiae strains for efficient conversion of lignocellulosic hydrolysates.","l-Arabinose transporter; Metabolic engineering; Penicillium; Proton symport; Second-generation bioethanol; Sugar transport; Transcriptome; Yeast","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:6c333b21-139c-4569-9e87-a9a40b703b92","http://resolver.tudelft.nl/uuid:6c333b21-139c-4569-9e87-a9a40b703b92","Perspectives for the microbial production of methyl propionate integrated with product recovery","Pereira, Joana P.C. (TU Delft BT/Bioprocess Engineering); van der Wielen, L.A.M. (TU Delft BT/Bioprocess Engineering); Straathof, Adrie J.J. (TU Delft BT/Bioprocess Engineering)","","2018","A new approach was studied for bio-based production of methyl propionate, a precursor of methyl methacrylate. Recombinant E. coli cells were used to perform a cascade reaction in which 2-butanol is reduced to butanone using alcohol dehydrogenase, and butanone is oxidized to methyl propionate and ethyl acetate using a Baeyer-Villiger monooxygenase (BVMO). Product was removed by in situ stripping. The conversion was in line with a model comprising product formation and stripping kinetics. The maximum conversion rates were 1.14 g-butanone/(L h), 0.11 g-ethyl acetate/(L h), and 0.09 g-methyl propionate/(L h). The enzyme regioselectivity towards methyl propionate was 43% of total ester. Starting from biomass-based production of 2-butanol, full-scale ester production with conventional product purification was calculated to be competitive with petrochemical production if the monooxygenase activity and regioselectivity are enhanced, and the costs of bio-based 2-butanol are minimized.","Biomaterials; Bioprocess engineering; Integrated product recovery; Modeling","en","journal article","","","","","","Accepted Author Manuscript","","2020-05-01","","","BT/Bioprocess Engineering","","",""
"uuid:69e5b965-a6e8-4e7c-8579-00026bc80683","http://resolver.tudelft.nl/uuid:69e5b965-a6e8-4e7c-8579-00026bc80683","Exploiting Bacteriophage Proteomes: The Hidden Biotechnological Potential","Santos, Sílvio B. (University of Minho); Costa, Ana Rita (University of Minho); Carvalho, Carla (University of Minho; International Iberian Nanotechnology Laboratory); Luzia de Nobrega, F. (TU Delft BN/Stan Brouns Lab; University of Minho; Kavli institute of nanoscience Delft); Azeredo, Joana (University of Minho)","","2018","Bacteriophages encode many distinct proteins for the successful infection of a bacterial host. Each protein plays a specific role in the phage replication cycle, from host recognition, through takeover of the host machinery, and up to cell lysis for progeny release. As the roles of these proteins are being revealed, more biotechnological applications can be anticipated. Phage-encoded proteins are now being explored for the control, detection, and typing of bacteria; as vehicles for drug delivery; and for vaccine development. In this review, we discuss how engineering approaches can be used to improve the natural properties of these proteins and set forth the most innovative applications that demonstrate the unlimited biotechnological potential held by phage-encoded proteins.","anti-CRISPR; bacteria control and detection; bacteriolytic activity; genetic engineering; host specificity; Phage-encoded proteins","en","journal article","","","","","","Accepted Author Manuscript","","2019-08-15","","","BN/Stan Brouns Lab","","",""
"uuid:1b317889-e0f7-4eb8-8695-b04258586de7","http://resolver.tudelft.nl/uuid:1b317889-e0f7-4eb8-8695-b04258586de7","Roadmap for design of surgical equipment for safe surgery worldwide","Oosting, R.M. (TU Delft Medical Instruments & Bio-Inspired Technology); Dankelman, J. (TU Delft Medical Instruments & Bio-Inspired Technology); Wauben, L.S.G.L. (Rotterdam University of Applied Sciences); Madete, J. (Jomo Kenyatta University of Agriculture and Technology); Groen, R. S. (Johns Hopkins University)","Perkins, Ed (editor); Figueira, Silvia (editor)","2018","Safe and affordable surgery is not accessible for five billion people when they need it. Multiple surgical capacity studies have shown that hospitals in low-And-middle income countries do not have complete coverage of basic surgical equipment such as, theatre lights, anesthesia machines and electro surgical units. Currently, almost all equipment is designed and manufactured with a main focus on the context in high income countries. The context in low-And-middle income countries in which surgical equipment is used, differs from high income countries, especially in terms of financial resources and access to maintenance, spare parts and consumables. The aim of this study is to present a roadmap for design of surgical equipment for worldwide use. The roadmap consists of four phases: before the start of a design project a clear need for certain surgical equipment should be identified (Phase 0). During Phase 1 the context should be researched thoroughly by determining the barriers encountered by patients to surgical care, the structure of the health care system and if the aspects required for safe surgery are in place. In Phase 2 the implementation strategy and design requirements should be determined and in phase 3 prototyping starts in close interaction with local end-users. We believe that designers should strive for design that is of the same quality and complies with the same safety regulations as equipment designed for HICs. In this way user and patient safety can be assured in any setting worldwide. And we advocate for surgical equipment that fits the context optimally and that will be applicable in comparable settings globally.","biomedical engineering; design; Low-And-Middle Income Countries (LMICs); Surgery; surgical equipment","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-07-07","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:35e229bf-db38-4347-91d7-7cc43ddd5f8f","http://resolver.tudelft.nl/uuid:35e229bf-db38-4347-91d7-7cc43ddd5f8f","In-plane friction behaviour of a ferrofluid bearing","Lampaert, S.G.E. (TU Delft Mechatronic Systems Design); Fellinger, B. J. (Student TU Delft); Spronck, J.W. (TU Delft Mechatronic Systems Design); van Ostayen, R.A.J. (TU Delft Mechatronic Systems Design)","","2018","Ferrofluid bearings have been demonstrated to be very interesting for precision positioning systems. The friction of these bearings is free of stick-slip which results in an increase of precision. More knowledge on the friction behaviour of these bearings is important for there application in precision positioning systems. This paper demonstrates that the friction of a ferrofluid bearing can be modelled by a viscous damper model and provides a basic model to predict the friction behaviour of a bearing design. The model consists of a summation of a Couette flow with a Poiseuille flow such that there is no net fluid transport under the bearing pads. The model is experimentally validated on a six degrees of freedom stage using ferrofluid bearings. A stiffness in the form of a closed-loop control gain is introduced in the system to create a resonance peak at the desired frequency. The damping coefficient can be identified from the peak height of the resonance, since the peak height is the ratio of total energy to dissipated energy in the system. The results show that the newly derived model can be used to make an estimate of the damping coefficient for small(∼1mm) stroke translations. Furthermore, the model shows that the load capacity of a ferrofluid pocket bearing is affected during sliding.","Fluid dynamics; Magnetics; Modelling; Precision engineering; Viscous damping","en","journal article","","","","","","","","","","","Mechatronic Systems Design","","",""
"uuid:f07ad4ca-7b48-4aff-bf82-7c1553049564","http://resolver.tudelft.nl/uuid:f07ad4ca-7b48-4aff-bf82-7c1553049564","Cross-Cultural Engineering: The role of Dutch civil engineering in modern port planning in Japan (1870s-1890s)","Iwamoto, K. (TU Delft OLD History of Architecture & Urban Planning; Kyoto University); Hein, C.M. (TU Delft History, Form & Aesthetics)","","2018","This is particularly true for the Japanese case, where civil engineering has played a major role in the country’s modernization and westernization since the mid-19th century. The design and engineering of Japanese ports from the 1870s to 1890s is a case in point. This contribution explores the degree to which civil engineering engaged with port city design by studying investigative reports, design drawings and survey maps established by Dutch civil engineers in collaboration with Japanese practitioners. It identifies three types of cross-cultural engineering. 1. Building a new port: Some Dutch engineers proposed complex projects combining water management and port basins, jetties with urban form, but these were only partially implemented. 2. Improvement of Port Functions: The Japanese engineers were particularly receptive for the design of breakwaters, the practice of dredging and the construction of basins; notably the technique of breakwaters became a staple in textbook and spread through Japan. 3: Development of the Port. The engineers developed a complete vision for a new port, but diverse reasons hindered realization, including natural features that disturbed the construction of the port. These three types stand as examples of the intricacies of cross cultural engineering in engineering and planning.","Cross-cultural Engineering; Civil Engineering; Port Planning; Dutch Engineers","en","conference paper","Delft University of Technology","","","","","","","","","","OLD History of Architecture & Urban Planning","","",""
"uuid:b2753a94-bd0b-49a6-a18b-885cc4ed6650","http://resolver.tudelft.nl/uuid:b2753a94-bd0b-49a6-a18b-885cc4ed6650","A CRISPR/Cas9-based exploration into the elusive mechanism for lactate export in Saccharomyces cerevisiae","Mans, R. (TU Delft BT/Industriele Microbiologie); Else-Hassing, J. (TU Delft BT/Industriele Microbiologie); Wijsman, M. (TU Delft BT/Industriele Microbiologie); Giezekamp, Annabel (Student TU Delft); Pronk, J.T. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie; KTH Royal Institute of Technology)","","2017","CRISPR/Cas9-based genome editing allows rapid, simultaneous modification of multiple genetic loci in Saccharomyces cerevisiae. Here, this technique was used in a functional analysis study aimed at identifying the hitherto unknown mechanism of lactate export in this yeast. First, an S. cerevisiae strain was constructed with deletions in 25 genes encoding transport proteins, including the complete aqua(glycero)porin family and all known carboxylic acid transporters. The 25-deletion strain was then transformed with an expression cassette for Lactobacillus casei lactate dehydrogenase (LcLDH). In anaerobic, glucose-grown batch cultures this strain exhibited a lower specific growth rate (0.15 vs. 0.25 h-1) and biomass-specific lactate production rate (0.7 vs. 2.4 mmol g biomass-1 h-1) than an LcLDH-expressing reference strain. However, a comparison of the two strains in anaerobic glucose-limited chemostat cultures (dilution rate 0.10 h-1) showed identical lactate production rates. These results indicate that, although deletion of the 25 transporter genes affected the maximum specific growth rate, it did not impact lactate export rates when analysed at a fixed specific growth rate. The 25-deletion strain provides a first step towards a 'minimal transportome' yeast platform, which can be applied for functional analysis of specific (heterologous) transport proteins as well as for evaluation of metabolic engineering strategies.","Carboxylic acid; Cas9; CRISPR; Diffusion; Genome editing; Metabolic engineering","en","journal article","","","","","","","","2018-11-14","","","BT/Industriele Microbiologie","","",""
"uuid:7f631f4e-3ffa-42fc-9ed1-c98af583ea28","http://resolver.tudelft.nl/uuid:7f631f4e-3ffa-42fc-9ed1-c98af583ea28","Synthesis and evaluation of porous titanium scaffolds prepared with the space holder method for bone tissue engineering","Arifvianto, B. (TU Delft Biomaterials & Tissue Biomechanics)","van der Helm, F.C.T. (promotor); Zhou, J. (copromotor); Delft University of Technology (degree granting institution)","2017","Loss of function and impaired life quality as a result of large bone defects remain a serious problem in the society. Basically, the bone tissue has the capability of healing by itself when fractured. However, impaired healing may occur, leading to delayed union or even non-union when a bone segment is excised above a critical size. In recent years, bone tissue engineering has received increasing attention in the biomedical research community as an alternative approach to bone defect reconstruction. With this approach, damaged bone tissue can be repaired and remodelled with new bone cells at the defect site. For this purpose, a synthetic porous material, namely scaffold, is needed to act as a template to facilitate cellular activities, such as the migration
and proliferation of osteoblasts and mesenchymal cells, as well as the transport of nutrients and oxygen required for vascularization during bone tissue development at the defect site. Currently, titanium is considered to be a preferred biomaterial for bone tissue engineering scaffolds owing to its excellent biocompatibility and mechanical properties. So far, the space holder method has been preferably used for the fabrication of titanium scaffolds with high porosity and open, interconnected pores for bone tissue engineering. Despite a large number of studies on the scaffold fabrication with this method, the mechanisms involved and the way to control the porous structure of scaffolds during fabrication have not yet been fully understood.","synthesis; evaluation; titanium scaffold; space holder method; bone tissue engineering","en","doctoral thesis","","978-94-6186-851-0","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:f2076a63-f6e3-4333-aa97-49b9bebc20f9","http://resolver.tudelft.nl/uuid:f2076a63-f6e3-4333-aa97-49b9bebc20f9","Change analysis of laser scans of laboratory rock slopes subject to wave attack testing","Shen, Y. (TU Delft Optical and Laser Remote Sensing; Hohai University); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing); Hofland, Bas (TU Delft Hydraulic Structures and Flood Risk); Kramer, R.","","2017","For better understanding how coastal structures with gentle slopes behave during high energy events, a wave attack experiment representing a storm of 3000 waves was performed in a flume facility. Two setups with different steepness of slope were compared under the same conditions. In order to quantify changes in the rock slopes after the wave attack, a terrestrial laser scanner was used to obtain 3D coordinates of the rock surface before and after each experiment. Next, through a series of processing steps, the point clouds were converted to a suitable 2D raster for change analysis. This allowed to estimate detailed and quantitative change information. The results indicate that the area around the artificial coast line, defined as the intersection between sloped surface and wave surface, is most strongly affected by wave attacks. As the distances from the sloped surface to the waves are shorter, changes for the mildly sloped surface, slope 1 (1: 10), are distributed over a larger area compared to the changes for the more steeply sloped surface, slope 2 (1: 5). The results of this experiment show that terrestrial laser scanning is an effective and feasible method for change analysis of rock slopes in a laboratory setting. Most striking results from a process point of view is that the transport direction of the rocks change between the two different slopes: from seaward transport for the steeper slope to landward transport for the milder slope.","Breakwater; Change Analysis; Coastal Engineering; TLS; Water Flume; Wave Attack","en","conference paper","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:41369284-f0ea-4057-adf3-26826893cf85","http://resolver.tudelft.nl/uuid:41369284-f0ea-4057-adf3-26826893cf85","The effects of perceived value and stakeholder satisfaction on software project impact","Huijgens, H.K.M. (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology); van Solingen, D.M. (TU Delft Software Engineering)","","2017","Context: In this paper we present a multiple case study on the insights of software organizations into stakeholder satisfaction and (perceived) value of their software projects. Our study is based on the notion that quantifying and qualifying project size, cost, duration, defects, and estimation accuracy needs to be done in relation with stakeholder satisfaction and perceived value. Objectives: We contrast project metrics such as cost, duration, number of defects and estimation accuracy with stakeholder satisfaction and perceived value. Method: In order to find out whether our approach is practically feasible in an industrial setting, we performed two case studies; one in a Belgian telecom company and the other in a Dutch software company. Results: In this study we evaluate 22 software projects that were delivered during one release in the Belgian telecom company, and 4 additional large software releases (representing an extension of 174% in project size) that were delivered in a Dutch software company. Eighty-three (83) key stakeholders of two companies provide stakeholder satisfaction and perceived value measurements in 133 completed surveys. Conclusions: We conclude that a focus on shortening overall project duration, and improving communication and team collaboration on intermediate progress is likely to have a positive impact on stakeholder satisfaction and perceived value. Our study does not provide any evidence that steering on costs helped to improve these. As an answer to our research question - how do stakeholder satisfaction and perceived value relate to cost, duration, defects, size and estimation accuracy of software projects? - we found five take-away-messages.","Cost duration index; Evidence-based software engineering; Perceived value; Software economics; Stakeholder satisfaction","en","journal article","","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:8cb1a309-0454-459c-a1f5-0d43b2dfd5fb","http://resolver.tudelft.nl/uuid:8cb1a309-0454-459c-a1f5-0d43b2dfd5fb","Laboratory evolution of a biotin-requiring Saccharomyces cerevisiae strain for full biotin prototrophy and identification of causal mutations","Bracher, J.M. (TU Delft BT/Industriele Microbiologie); de Hulster, A.F. (TU Delft BT/Industriele Microbiologie); Koster, C.C. (TU Delft BT/Industriele Microbiologie); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Industriele Microbiologie)","","2017","Biotin prototrophy is a rare, incompletely understood, and industrially relevant characteristic of Saccharomyces cerevisiae strains. The genome of the haploid laboratory strain CEN.PK113-7D contains a full complement of biotin biosynthesis genes, but its growth in biotin-free synthetic medium is extremely slow (specific growth rate [μ] ≈ 0.01 h-1). Four independent evolution experiments in repeated batch cultures and accelerostats yielded strains whose growth rates (μ ≤ 0.36 h-1) in biotin-free and biotin-supplemented media were similar. Whole-genome resequencing of these evolved strains revealed up to 40-fold amplification of BIO1, which encodes pimeloyl-coenzyme A (CoA) synthetase. The additional copies of BIO1 were found on different chromosomes, and its amplification coincided with substantial chromosomal rearrangements. A key role of this gene amplification was confirmed by overexpression of BIO1 in strain CEN.PK113-7D, which enabled growth in biotin-free medium (μ= 0.15 h-1). Mutations in the membrane transporter genes TPO1 and/or PDR12 were found in several of the evolved strains. Deletion of TPO1 and PDR12 in a BIO1-overexpressing strain increased its specific growth rate to 0.25 h-1. The effects of null mutations in these genes, which have not been previously associated with biotin metabolism, were nonadditive. This study demonstrates that S. cerevisiae strains that carry the basic genetic information for biotin synthesis can be evolved for full biotin prototrophy and identifies new targets for engineering biotin prototrophy into laboratory and industrial strains of this yeast.","Adaptive laboratory evolution; Biotin; Prototrophy; Reverse metabolic engineering; Saccharomyces cerevisiae; Vitamin biosynthesis; Whole-genome sequencing","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:8cfb6f84-21c5-4a94-8b9d-fb66835c7ce8","http://resolver.tudelft.nl/uuid:8cfb6f84-21c5-4a94-8b9d-fb66835c7ce8","Structural evaluation of multifunctional flood defenses using generic element types","Voorendt, M.Z. (TU Delft Hydraulic Structures and Flood Risk); Vrijling, J.K. (TU Delft Hydraulic Structures and Flood Risk); Voortman, HG (ARCADIS Nederland)","Wallendorf, Louise (editor); Cox, Daniel (editor)","2017","A lack of appropriate guidelines for the design and assessment hampers the development of multifunctional flood defenses like parking garages in quays and houses in dikes. The aim of the present paper, therefore, is to gain insight in the structural performance of multifunctional flood defenses and to provide a tool to evaluate design alternatives. For this purpose we have developed a generic method to determine the function of structural elements regarding flood
protection. A study of diverse multifunctional flood defenses showed that the derived structural element types are indeed generic. We then applied the method to a real case, which showed that it factually provides more clarity and insight in the advantages and disadvantages of adding functions to flood defenses. This method will therefore advance the design and application of
multifunctional flood defenses.","flood defences; coastal protection; engineering design","en","conference paper","ASCE - COPRI","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:31ec6c27-2f53-4322-ac2f-2852d58dfa05","http://resolver.tudelft.nl/uuid:31ec6c27-2f53-4322-ac2f-2852d58dfa05","Design principles of multifunctional flood defences","Voorendt, M.Z. (TU Delft Hydraulic Structures and Flood Risk)","Vrijling, J.K. (promotor); Delft University of Technology (degree granting institution)","2017","Multifunctional flood defences are structures that primarily protect land from being covered by water and simultaneously serve other purposes. The present dissertation focuses on the combination of flood protection with functions that are fulfilled by means of buildings and objects, with a high degree of structural integration. This can typically be found in the urban context, where the combination of long-term flood protection and spatial quality is considered crucial for the viability of cities along rivers and seas.
The design of multifunctional flood defences is more complicated than of plain flood defences, as two incompatible design cultures are involved: spatial design and hydraulic engineering. Moreover, the structural composition of multifunctional flood defences is more complex and more diverse than of plain flood defences. Therefore, an overall, integrated, design method was developed that maintains the strengths of both existing approaches, but avoids their weaknesses. In addition, a method is proposed for the design phase of verifying the flood protection function. The methods were validated by design teams of students and by additional case studies.","flood defences; multidisciplinary design; hydraulic engineering; integrated design","en","doctoral thesis","","978-94-028-0678-6","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:36a09c51-586a-487f-a175-1113d072745c","http://resolver.tudelft.nl/uuid:36a09c51-586a-487f-a175-1113d072745c","Bounds for Cooperative Locality Using Generalized Hamming Weights","Abdel-Ghaffar, Khaled A.S. (University of California); Weber, J.H. (TU Delft Discrete Mathematics and Optimization)","","2017","The Cadambe-Mazumdar bound gives a necessary condition for a code to have a certain locality in case of a single erasure in terms of length, dimension, and Hamming distance of the code and of certain shortened codes. The bound has been generalized by Rawat, Mazumdar, and Vishwanath to recover multiple erasures in a cooperative repair scenario. In this paper, the generalized Hamming weights of the code and its shortened codes, which include the Hamming distance as one component, are incorporated to obtain bounds on locality to recover a single
erasure or multiple erasures cooperatively. The new bounds give sharper necessary conditions than existing bounds.","Maintenance engineering; Linear codes; Hamming distance; Hamming weight; Generators; Electronic mail","en","conference paper","IEEE","","","","","","","","","","Discrete Mathematics and Optimization","","",""
"uuid:72090752-81c2-44c1-a068-d329785f24fd","http://resolver.tudelft.nl/uuid:72090752-81c2-44c1-a068-d329785f24fd","Industrial relevance of chromosomal copy number variation in Saccharomyces yeasts","Gorter de Vries, A.R. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2017","Chromosomal copy number variation (CCNV) plays a key role in evolution and health of eukaryotes. The unicellular yeast Saccharomyces cerevisiae is an important model for studying the generation, physiological impact, and evolutionary significance of CCNV. Fundamental studies of this yeast have contributed to an extensive set of methods for analyzing and introducing CCNV. Moreover, these studies provided insight into the balance between negative and positive impacts of CCNV in evolutionary contexts. A growing body of evidence indicates that CCNV not only frequently occurs in industrial strains of Saccharomyces yeasts but also is a key contributor to the diversity of industrially relevant traits. This notion is further supported by the frequent involvement of CCNV in industrially relevant traits acquired during evolutionary engineering. This review describes recent developments in genome sequencing and genome editing techniques and discusses how these offer opportunities to unravel contributions of CCNV in industrial Saccharomyces strains as well as to rationally engineer yeast chromosomal copy numbers and karyotypes.","Aneuploidy; Evolutionary adaptation; Fermentation; Genome engineering; Industrial yeast; Industrial yeast fermentation; Strain improvement","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:114e6a7c-0e74-4d64-a031-210aa78c49e9","http://resolver.tudelft.nl/uuid:114e6a7c-0e74-4d64-a031-210aa78c49e9","Als de duinen breken: Once the Dunes Breach","Stive, M.J.F. (TU Delft Coastal Engineering)","","2017","Uittree rede","Duinen; Zandige kust; Zandmotor; Afscheidsrede; Dunes; Sandy Coast; Sand Engine; Valedictory address","en","public lecture","","","","","","Afscheidsrede, Uitgesproken bij het afscheid van het ambt van hoogleraar Kustwaterbouwkunde aan de Technische Universiteit Delft","","","","","Coastal Engineering","","",""
"uuid:1b0c2406-1097-4bb6-9f73-231580bb721c","http://resolver.tudelft.nl/uuid:1b0c2406-1097-4bb6-9f73-231580bb721c","Metabolic engineering strategies for optimizing acetate reduction, ethanol yield and osmotolerance in Saccharomyces cerevisiae","Papapetridis, I. (TU Delft BT/Industriele Microbiologie); van Dijk, M. (TU Delft BT/Industriele Microbiologie); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Industriele Microbiologie)","","2017","Background: Glycerol, whose formation contributes to cellular redox balancing and osmoregulation in Saccharomyces cerevisiae, is an important by-product of yeast-based bioethanol production. Replacing the glycerol pathway by an engineered pathway for NAD+-dependent acetate reduction has been shown to improve ethanol yields and contribute to detoxification of acetate-containing media. However, the osmosensitivity of glycerol non-producing strains limits their applicability in high-osmolarity industrial processes. This study explores engineering strategies for minimizing glycerol production by acetate-reducing strains, while retaining osmotolerance. Results: GPD2 encodes one of two S. cerevisiae isoenzymes of NAD+-dependent glycerol-3-phosphate dehydrogenase (G3PDH). Its deletion in an acetate-reducing strain yielded a fourfold lower glycerol production in anaerobic, low-osmolarity cultures but hardly affected glycerol production at high osmolarity. Replacement of both native G3PDHs by an archaeal NADP+-preferring enzyme, combined with deletion of ALD6, yielded an acetate-reducing strain the phenotype of which resembled that of a glycerol-negative gpd1Δ gpd2Δ strain in low-osmolarity cultures. This strain grew anaerobically at high osmolarity (1 mol L-1 glucose), while consuming acetate and producing virtually no extracellular glycerol. Its ethanol yield in high-osmolarity cultures was 13% higher than that of an acetate-reducing strain expressing the native glycerol pathway. Conclusions: Deletion of GPD2 provides an attractive strategy for improving product yields of acetate-reducing S. cerevisiae strains in low, but not in high-osmolarity media. Replacement of the native yeast G3PDHs by a heterologous NADP+-preferring enzyme, combined with deletion of ALD6, virtually eliminated glycerol production in high-osmolarity cultures while enabling efficient reduction of acetate to ethanol. After further optimization of growth kinetics, this strategy for uncoupling the roles of glycerol formation in redox homeostasis and osmotolerance can be applicable for improving performance of industrial strains in high-gravity acetate-containing processes.","Acetic acid; Bioethanol; NADH; NADPH; Osmotic stress; Redox engineering; Yeast","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:4f34f992-ea2b-45a0-afd7-8a257550b300","http://resolver.tudelft.nl/uuid:4f34f992-ea2b-45a0-afd7-8a257550b300","Diesel A-M (A-Modular) Model Proposed: Expanding the Diesel A model for advanced turbocharging capabilities","Loonstijn, M.A. (TU Delft Ship Design, Production and Operations)","","2017","The Diesel A model has been developed with the idea of looking at overall engine cycle performance in a larger system. As such, the goal has always been to provide an acceptable prediction of the engine performance without sacrificing the computational performance of the model. The simplest form of the Diesel A model has only a single integrator that is used to estimate the charge pressure based on the available heat at the end of the closed cylinder process. This method has recently been improved by adding a more realistic estimation for the charge pressure through the Buchi equation. This has proved
to be an improvement but has also created a new problem: the need for a second integrator to close an algebraic loop in the model. This second integrator represents the time delay of the outlet receiver building up pressure but it has no direct physical derivation. Furthermore this method is still not suitable for advanced turbocharging strategies, and thus an improvement is proposed in this report.","Diesel Engine; Mean value model; Turbocharger","en","report","Delft University of Technology","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:39ffac87-c07b-42ae-b706-f3afe69ba21b","http://resolver.tudelft.nl/uuid:39ffac87-c07b-42ae-b706-f3afe69ba21b","A theory of thermodynamics for nanoscale quantum systems","Ng, N.H.Y. (TU Delft Quantum Information and Software)","Wehner, S.D.C. (promotor); Delft University of Technology (degree granting institution)","2017","Thermodynamics is one of the main pillars of theoretical physics, and it has a special appeal of having wide applicability to a large variety of different physical systems. However, many assumptions in thermodynamics apply only to systems which are bulk material, i.e. consisting a large number of microscopic classical particles. Due to the advancement of designing nanoscale engines, especially in the light of devices that are used today in the processing of quantum information, is thermodynamics still applicable? Can we refine the core principles of thermodynamics to suit such nanoscale quantum systems as well? The central aim of this thesis is to construct a theory of thermodynamics that holds for nanoscale quantum systems, even those as small and simple as a single qubit. We do this by starting out from the core basics of quantum theory: unitary dynamics on closed quantum systems. We adapt a resource theoretic approach inspired by quantum information theory, which defines the quantum states and operations allowed to be used in a thermodynamic evolution. With this framework that naturally adopts the first law as an energy preserving condition, we show the refinement of both the zeroeth and second law of thermodynamics. The zeroeth law explains the physical significance of the Gibbs thermal state. On the other hand, we show that the second law sees refinement in the quantum nanoregime: instead of having the free energy as the sole quantity dictating the possibility of a thermodynamic state transition, we derive a family of generalized free energies that also constitute necessary conditions for a transition to occur. Moreover, these conditions become sufficient for states which are block-diagonal in the energy eigenbasis. In this thesis, we also brought our approach of thermodynamics to the next step: we apply our findings on the second laws, in order to analyze the maximum achievable efficiency for quantum heat engines. In classical thermodynamics, the Carnot efficiency has been long known as the theoretical maximum which does not depend on the specific structure of the thermal baths used, but only on its temperature. With the additional free energies we discover, we show that although quantum heat engines may achieve the Carnot efficiency, such an achievability is no longer independent of the Hamiltonians of the thermal baths. In other words, we find additional restrictions that surface in the study of quantum nanoscale heat engines, which are a direct consequence of the generalized second laws. This has provided us with a deeper understanding into the fundamental limitations of how efficient devices can be made in the realm of microscopic quantum systems.","quantum thermodynamics; quantum information theory; resource theories; single-shot work extraction; quantum heat engines","en","doctoral thesis","","978-94-6295-588-2","","","","","","","","","Quantum Information and Software","","",""
"uuid:6e798054-211f-4396-8a76-eeaf41aba53e","http://resolver.tudelft.nl/uuid:6e798054-211f-4396-8a76-eeaf41aba53e","A Methodical Approach on Conceptual Structural Design","Horikx, M.P. (TU Delft Integral Design & Management)","van der Horst, A.Q.C. (promotor); de Ridder, H.A.J. (promotor); Delft University of Technology (degree granting institution)","2017","The subject of this academic research thesis is a methodical approach on the complex problem-solving process of structural conceptual design.
For this relatively unexplored problem, an exploratory research is conducted by systematically zooming in from the whole to the part and from coarse to fine. The so explored methodical approach on conceptual structural design leads to a controlled build-up of insight into the behaviour of the structure and supports the actual successive design decisions during the conceptual design phase.","Structural engineering; Conceptual design; Control","en","doctoral thesis","","978-94-6186-763-6","","","","","","","","","Integral Design & Management","","",""
"uuid:78cb82a1-8417-42e2-bd21-43ce333780c0","http://resolver.tudelft.nl/uuid:78cb82a1-8417-42e2-bd21-43ce333780c0","Spreadsheet testing in practice","Roy, S. (TU Delft Software Engineering); Hermans, F.F.J. (TU Delft Software Engineering); van Deursen, A. (TU Delft Software Technology)","Pinzger, Martin (editor); Bavota, Gabriele (editor); Marcus, Andrian (editor)","2017","Despite being popular end-user tools, spreadsheets suffer from the vulnerability of error-proneness. In software engineering, testing has been proposed as a way to address errors. It is important therefore to know whether spreadsheet users also test, or how do they test and to what extent, especially since most spreadsheet users do not have the training, or experience, of software engineering principles. Towards this end, we conduct a two-phase mixed methods study. First, a qualitative phase, in which we interview 12 spreadsheet users, and second, a quantitative phase, in which we conduct an online survey completed by 72 users. The outcome of the interviews, organized into four different categories, consists of an overview of test practices, perceptions of spreadsheet users about testing, a set of preventive measures for avoiding errors, and an overview of maintenance practices for ensuring correctness of spreadsheets over time. The survey adds to the findings by providing quantitative estimates indicating that ensuring correctness is an important concern, and a major fraction of users do test their spreadsheets. However, their techniques are largely manual and lack formalism. Tools and automated supports are rarely used.","Testing; Interviews; Software engineering; Manuals; Encoding; Training; Software","en","conference paper","IEEE","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:0df3296c-9a60-4243-b677-30507c5b38ea","http://resolver.tudelft.nl/uuid:0df3296c-9a60-4243-b677-30507c5b38ea","SPAD imagers for super resolution localization microscopy enable analysis of fast fluorophore blinking","Antolović, I.M. (TU Delft (OLD)Applied Quantum Architectures); Burri, S. (Swiss Federal Institute of Technology); Bruschini, Claudio (Swiss Federal Institute of Technology); Hoebe, Ron A. (Universiteit van Amsterdam); Charbon-Iwasaki-Charbon, E. (TU Delft (OLD)Applied Quantum Architectures; TU Delft OLD QCD/Charbon Lab; Swiss Federal Institute of Technology)","","2017","sCMOS imagers are currently utilized (replacing EMCCD imagers) to increase the acquisition speed in super resolution localization microscopy. Single-photon avalanche diode (SPAD) imagers feature frame rates per bit depth comparable to or higher than sCMOS imagers, while generating microsecond 1-bit-frames without readout noise, thus paving the way to in-depth time-resolved image analysis. High timing resolution can also be exploited to explore fluorescent dye blinking and other photophysical properties, which can be used for dye optimization. We present the methodology for the blinking analysis of fluorescent dyes on experimental data. Furthermore, the recent use of microlenses has enabled a substantial increase of SPAD imager overall sensitivity (12-fold in our case), reaching satisfactory values for sensitivity-critical applications. This has allowed us to record the first super resolution localization microscopy results obtained with a SPAD imager, with a localization uncertainty of 20 nm and a resolution of 80 nm.","Electrical and electronic engineering; Imaging and sensing; Super-resolution microscopy","en","journal article","","","","","","","","","","","(OLD)Applied Quantum Architectures","","",""
"uuid:325ebcfb-f920-400c-8ef6-21b2305b6920","http://resolver.tudelft.nl/uuid:325ebcfb-f920-400c-8ef6-21b2305b6920","Ice-induced vibrations of vertically sided offshore structures","Hendrikse, H. (TU Delft Applied Mechanics)","Metrikine, A. (promotor); Loset, Sveinung (promotor); Delft University of Technology (degree granting institution)","2017","Offshore developments in ice-covered waters, such as the Arctic Ocean or Baltic Sea, have received increasing attention from the petroleum and wind power industries over the past decade. Sustainable developments in such waters can contribute to a balanced energy future provided that the deployed offshore structures are designed to be safe. The potential development of ice-induced vibrations has to be considered in the design of bottom founded offshore structures with a vertically sided waterline cross-section subject to ice. These vibrations, originating from dynamic interaction between the ice and structure, can result in high global peak loads and significantly contribute to the fatigue of structures. A governing theory which can explain the development of ice-induced vibrations has not yet been defined, despite several decades of research. As a consequence the tools required for detailed design of structures subject to ice-induced vibrations are not yet available. The main objective of this study is to define a physical mechanism which can explain the development of ice-induced vibrations and is consistent with existing experimental and full-scale observations. A literature study and new experiments in the large ice-basin at HSVA in Hamburg have resulted in the identification of key features of the interaction process. A new theory has been proposed, namely that the variations in the contact area between the intact ice and structure govern ice-induced vibrations. These variations result from the velocity dependent deformation and failure behaviour of the ice. Based on the theory a phenomenological model for the prediction of ice-induced vibrations has been developed of which the predictions have been shown to be consistent with experimental observations. Additionally, the limiting effect of ice buckling on ice-induced vibrations has been studied and practical application of the model illustrated on the basis of simulation examples.","Ice-induced vibrations; ice engineering; offshore structures","en","doctoral thesis","","978-94-6186-746-9","","","","","","","","","Applied Mechanics","","",""
"uuid:73276743-0520-4d3f-92fa-befcfc0a3bcf","http://resolver.tudelft.nl/uuid:73276743-0520-4d3f-92fa-befcfc0a3bcf","The influence of tip shape on bending force during needle insertion","van de Berg, N.J. (TU Delft Medical Instruments & Bio-Inspired Technology); de Jong, T.L. (TU Delft Medical Instruments & Bio-Inspired Technology); van Gerwen, D.J. (TU Delft Medical Instruments & Bio-Inspired Technology); Dankelman, J. (TU Delft Medical Instruments & Bio-Inspired Technology); van den Dobbelsteen, J.J. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2017","Steering of needles involves the planning and timely modifying of instrument-tissue force interactions to allow for controlled deflections during the insertion in tissue. In this work, the effect of tip shape on these forces was studied using 10 mm diameter needle tips. Six different tips were selected, including beveled and conical versions, with or without pre-bend or pre-curve. A six-degree-of-freedom force/torque sensor measured the loads during indentations in tissue simulants. The increased insertion (axial) and bending (radial) forces with insertion depth-the force-displacement slopes-were analyzed. Results showed that the ratio between radial and axial forces was not always proportional. This means that the tip load does not have a constant orientation, as is often assumed in mechanics-based steering models. For all tip types, the tip-load assumed a more radial orientation with increased axial load. This effect was larger for straight tips than for pre-bent or pre-curved tips. In addition, the force-displacement slopes were consistently higher for (1) increased tip angles, and for (2) beveled tips compared to conical tips. Needles with a bent or curved tip allow for an increased bending force and a decreased variability of the tip load vector orientation.","Biomedical engineering; Scientific data","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:a49a086e-2566-4505-99ed-5c99307f1e45","http://resolver.tudelft.nl/uuid:a49a086e-2566-4505-99ed-5c99307f1e45","Mean value modelling of diesel engine combustion based on parameterized finite stage cylinder process","Sui, Congbiao (TU Delft Ship Design, Production and Operations; Harbin Engineering University); Song, Enzhe (Harbin Engineering University); Stapersma, D. (TU Delft Ship Design, Production and Operations); Ding, Y. (Harbin Engineering University)","","2017","Mean value diesel engine models are widely used since they focus on the main engine performance and can operate on a time scale that is longer than one revolution, and as a consequence use time steps that are much longer than crank-angle models. Mean Value First Principle (MVFP) models are not primarily intended for engine development but are used for systems studies that are become more important for engine users. In this paper two new variants of Seiliger processes, which characterize the engine in-cylinder process with finite stages are investigated, in particular their ability to correctly model the heat release by a finite number of combustion parameters. MAN 4L20/27 engine measurements are used and conclusions were drawn which Seiliger variant should be used and how to model the combustion shape for more engines. Then expressions to calculate the combustion parameters have been obtained by using a multivariable regression fitting method. The mean value diesel engine model has been corrected and applied to the simulation of a ship propulsion system which contains a modern MAN 18V32/40 diesel engine in its preliminary design stage and the simulation results have shown the capability of the integration of MVFP model into a larger system.","Combustion parameter; Combustion process; Diesel engine; Mean value model; Modelling","en","journal article","","","","","","Accepted Author Manuscript","","2019-05-15","","","Ship Design, Production and Operations","","",""
"uuid:c597758c-7b7e-4924-91a0-52d5b9badd57","http://resolver.tudelft.nl/uuid:c597758c-7b7e-4924-91a0-52d5b9badd57","Experimental and simulation-based investigations of marine diesel engine performance against static back pressure","Sapra, H.D. (TU Delft Ship Design, Production and Operations); Godjevac, M. (TU Delft Ship Design, Production and Operations); Visser, K. (TU Delft Ship Design, Production and Operations); Stapersma, D. (TU Delft Ship Design, Production and Operations); Dijkstra, Chris (Netherlands Defence Academy)","","2017","After-treatment technologies are adopted in automobiles and ships to meet strict emission regulations, which increase exhaust back pressure. Furthermore, underwater exhaust systems are employed on board ships to save space, and reduce noise and pollution on working decks. However, water at exhaust outlet creates a flow resistance for the exhaust gases, which adds to the back pressure. High back pressure reduces the operating limits of an engine, increases fuel consumption, and can lead to exhaust smoke. While the effects of back pressure were recognized earlier, there is a lack of experimentally validated research on the performance limits of a turbocharged, marine diesel engine against high back pressure for the entire operating window. The focus of this research is to provide a comprehensive understanding of back pressure effects on marine diesel engine performance, and to identify limits of acceptable back pressure along with methods to tackle high back pressure. In this work, a pulse turbocharged, medium speed, diesel engine was tested at different loads and engine speeds; against different values of static back pressure. Additionally, mean value model simulations could be validated and were used to compare the performance of a pulse and constant pressure turbocharged engine against high back pressures of 1 meter water-column (mWC), and for two different values of valve overlap. Using the validated simulation model, the conceptual basis for the engine smoke limit as well as for thermal overloading is investigated. A methodology applying the conceptual basis to define boundaries of acceptable back pressures has been presented in this paper. A combination of pulse turbocharger systems and small valve overlap showed to significantly improve back pressure handling capabilities of engines.","Back pressure; Engine experiments; Marine diesel engine performance; Mean value engine model; Thermal overloading; Underwater exhaust system","en","journal article","","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:34a0114b-5e39-4b52-9940-3a7e9f5a2982","http://resolver.tudelft.nl/uuid:34a0114b-5e39-4b52-9940-3a7e9f5a2982","Long term coastline monitoring derived from satellite imagery","Hagenaars, G.S. (Deltares); Luijendijk, Arjen (TU Delft Coastal Engineering; Deltares); de Vries, S. (TU Delft Coastal Engineering); de Boer, W.P. (Deltares)","Aagaard, T. (editor); Deigaard, R. (editor); Fuhrman, D. (editor)","2017","","satellite imagery; Google Earth Engine; coastline dynamics; coastal monitoring; positional accuracy; Dutch coast","en","conference paper","","","","","","","","","","","Coastal Engineering","","",""
"uuid:2938565f-4340-4d94-b9a1-2bd38aec5028","http://resolver.tudelft.nl/uuid:2938565f-4340-4d94-b9a1-2bd38aec5028","Information engineering for developing and testing coherent, integrated and context-dependent user interfaces","van Doorn, E.C. (TU Delft Cyber-Physical Systems); Horvath, I. (TU Delft Cyber-Physical Systems); Rusak, Z. (TU Delft Cyber-Physical Systems)","","2017","There has been an increase in the amount and complexity of traffic on Dutch inland waterways. Traffic management shifted from local traffic control to corridor traffic management. Due to these changes, operators in nautical traffic management centers experience difficulty to gain and maintain sufficient situation awareness. In our previous research, three groups of deficiencies of current situation awareness support have been identified. To overcome these deficiencies, a theoretical framework for information engineering user interface concepts was developed and used for designing three interface concepts. A coherent, an integrated and a context-dependent adaptable user interface were designed and implemented as testable prototypes. To support the process of information engineering, we combined user-centered design techniques with the formalism of set theory, directed graphs and semantic networks. From a methodological point of view, these proved to be useful both in conceptualization and implementation of the concepts. The usability of these concepts was tested in a simulator environment. The results show that the implemented prototypes represent an important improvement compared to the traditional interface solutions currently used by nautical traffic management operators. However, it was recognized that the coherent user interface implementation still suffered from a number of deficiencies. The context-dependent adaptable user interface was evaluated most positively.","Coherent; Concept development; Context-dependent adaptable; Deficiencies; Directed graph; Information engineering; Integrated; Semantic network; Set theory; Situation awareness; Usability testing; User interface","en","journal article","","","","","","","","","","","Cyber-Physical Systems","","",""
"uuid:7223f124-6816-4af2-8e2f-7eb7fea48896","http://resolver.tudelft.nl/uuid:7223f124-6816-4af2-8e2f-7eb7fea48896","Prospective techno-economic and environmental assessment of carbon capture at a refinery and CO2 utilisation in polyol synthesis","Fernandez Dacosta, C. (Universiteit Utrecht); Van Der Spek, Mijndert (Universiteit Utrecht); Hung, Christine Roxanne (Norwegian University of Science and Technology (NTNU)); Oregionni, Gabriel David (Norwegian University of Science and Technology (NTNU)); Skagestad, Ragnhild (Tel-Tek); Parihar, Prashant (Bharat Petroleum Corporation Limited); Gokak, D. T. (Bharat Petroleum Corporation Limited); Strømman, Anders Hammer (Norwegian University of Science and Technology (NTNU)); Ramirez, Andrea (TU Delft Energie and Industrie; Universiteit Utrecht)","","2017","CO2 utilisation is gaining interest as a potential element towards a sustainable economy. CO2 can be used as feedstock in the synthesis of fuels, chemicals and polymers. This study presents a prospective assessment of carbon capture from a hydrogen unit at a refinery, where the CO2 is either stored, or partly stored and partly utilised for polyols production. A methodology integrating technical, economic and environmental models with uncertainty analysis is used to assess the performance of carbon capture and storage or utilisation at the refinery. Results show that only 10% of the CO2 captured from an industrial hydrogen unit can be utilised in a commercial-scale polyol plant. This option has limited potential for large scale CO2 mitigation from industrial sources. However, CO2 capture from a hydrogen unit and its utilisation for the synthesis of polyols provides an interesting alternative from an economic perspective. The costs of CO2-based polyol are estimated at 1200 €/t polyol, 16% lower than those of conventional polyol. Furthermore, the costs of storing the remaining CO2 are offset by the benefits of cheaper polyol production. Therefore, the combination of CO2 capture and partial utilisation provides an improved business case over capture and storage alone. The environmental assessment shows that the climate change potential of this CO2 utilisation system is 23% lower compared to a reference case in which no CO2 is captured at the refinery. Five other environmental impact categories included in this study present slightly better performance for the utilisation case than for the reference case.","Abbreviations BEC bare erected cost; CC climate change; CCS carbon capture and storage; CCS/U carbon capture storage and utilisation; CCU carbon capture and utilisation; CCUS carbon capture utilization and storage; cPC cyclic propylene carbonate; DMC double metal cyanide; EDD environmental due diligence; EDDiCCUT Environmental Due Diligence of novel CO Capture and Utilization Technologies; EPCC engineering, procurement and construction costs; FD fossil depletion; FE freshwater eutrophication; FU functional unit; G glycerol; HP high pressure; HT human toxicity; LCA life cycle assessment; LCI life cycle inventory; LCOE levelised cost of electricity; LCOP levelised cost of product; LHV lower heating value; LP low pressure; MDEA methyl diethanolamine; MPG monopropylene glycol; NMVOC non-methane volatile organic carbon; PBP payback period; PEC purchased equipment costs; PMF particulate matter formation; PO propylene oxide; POF photochemical oxidant formation; PP polyether polyol; PPC polyethercarbonate polyol; PSA pressure swing adsorption; PU polyurethane; R&D research & development; REF reference case; SA system area; TA terrestrial acidification; WGS water gas shift","en","journal article","","","","","","","","","","","Energie and Industrie","","",""
"uuid:fedfd363-9894-4d65-ac47-75a40a0ccca9","http://resolver.tudelft.nl/uuid:fedfd363-9894-4d65-ac47-75a40a0ccca9","Safe-by-Design: from Safety to Responsibility","van de Poel, I.R. (TU Delft Values Technology and Innovation); Robaey, Z.H. (TU Delft BT/Biotechnology and Society)","","2017","Safe-by-design (SbD) aims at addressing safety issues already during the R&D and design phases of new technologies. SbD has increasingly become popular in the last few years for addressing the risks of emerging technologies like nanotechnology and synthetic biology. We ask to what extent SbD approaches can deal with uncertainty, in particular with indeterminacy, i.e., the fact that the actual safety of a technology depends on the behavior of actors in the value chain like users and operators. We argue that while indeterminacy may be approached by designing out users as much as possible in attaining safety, this is often not a good strategy. It will not only make it more difficult to deal with unexpected risks; it also misses out on the resources that users (and others) can bring for achieving safety, and it is undemocratic. We argue that rather than directly designing for safety, it is better to design for the responsibility for safety, i.e., designers should think where the responsibility for safety is best situated and design technologies accordingly. We propose some heuristics that can be used in deciding how to share and distribute responsibility for safety through design.","Design; Ethics; Indeterminacy; Nanotechnology; Responsibility; Risk; Safe-by-design; Safety; Safety engineering; SbD; Synthetic biology; Uncertainty; Users","en","journal article","","","","","","","","","","Values Technology and Innovation","BT/Biotechnology and Society","","",""
"uuid:4259e93c-e80b-4176-bd35-328140e1fe4e","http://resolver.tudelft.nl/uuid:4259e93c-e80b-4176-bd35-328140e1fe4e","The effects of curriculum overhaul: investigating the students’ experience","van den Bogaard, M.E.D. (Universiteit Leiden); Klaassen, R.G. (TU Delft OLD E&SS education center FOCUS; 4TU.Centre for Engineering Education)","","2017","In this study, the final part of an overarching project on curriculum design and implementation executed at Delft University of Technology is presented. The last step in this research is to establish how the students perceive their new curricula. To that end a survey was developed using standardized questions on self-determination, motivation, self-efficacy, engineering education attributes, doability and study load of the programme. In addition, measures of student progress were collected in a programme for Architecture and the Built Environment and electrical Engineering. Relationships between the variables were established, but the relationship with progress was not strong. There were significant differences between the programmes, some of which may have a relationship with the way the curriculum was designed.","Curriculum Development, Engineering Education; Engineering education","en","conference paper","Universidad de los andes","","","","","","","","","","OLD E&SS education center FOCUS","","",""
"uuid:531dd12c-6fe5-48c9-8c4e-bfef44088b3c","http://resolver.tudelft.nl/uuid:531dd12c-6fe5-48c9-8c4e-bfef44088b3c","The Dawning of the Ethics of Environmental Robots","Robbins-van Wynsberghe, A.L. (TU Delft Ethics & Philosophy of Technology); Donhauser, Justin (University of Western Ontario)","","2017","Environmental scientists and engineers have been exploring research and monitoring applications of robotics, as well as exploring ways of integrating robotics into ecosystems to aid in responses to accelerating environmental, climatic, and biodiversity changes. These emerging applications of robots and other autonomous technologies present novel ethical and practical challenges. Yet, the critical applications of robots for environmental research, engineering, protection and remediation have received next to no attention in the ethics of robotics literature to date. This paper seeks to fill that void, and promote the study of environmental robotics. It provides key resources for further critical examination of the issues environmental robots present by explaining and differentiating the sorts of environmental robotics that exist to date and identifying unique conceptual, ethical, and practical issues they present.","Ecological robots; Environmental engineering; Environmental robotics; Ethics and technology; Robot ethics","en","journal article","","","","","","","","","","","Ethics & Philosophy of Technology","","",""
"uuid:2930a97d-3139-4455-a60c-bbdc8622d374","http://resolver.tudelft.nl/uuid:2930a97d-3139-4455-a60c-bbdc8622d374","Preparing to be unprepared: Training for resilience","Passenier, D (Vrije Universiteit Amsterdam); Pool, D.M. (TU Delft Control & Simulation); Rankin, A (Linköping University); Sharpanskykh, Alexei (TU Delft Air Transport & Operations)","","2017","Training methods for operators working under high pressure and in dynamic, unpredictable settings could benefit from a focus on resilience. In such settings, formal training often focuses on procedural conformity to train for particular scenarios, but resilient performance taps into a wider experience base and often more tacit skills. In this paper, we formulate a research agenda to develop useful theoretical insights about training for resilience. Our discussion follows recent developments on organizational routines, which suggest that sources of inertia and conformity, such as strict procedural training, can also enable operators’ resourcefulness. Drawing from our diverse research experiences, we discuss the training needs for 1) developing or attenuating techniques for flexible procedural use, grounded in a rich qualitative understanding of practical experience; 2) the possibility to train skills that are more broadly applicable than specific training scenarios through simulation training methods; and 3) the development of training programs based on knowledge of “work-as-done” through Agent Based Modelling and Simulation methodologies and behavioral theories.","Resilience Engineering; Training; Unexpected Events; Aviation","en","conference paper","Resilience Engineering Association","","","","","","","","","","Control & Simulation","","",""
"uuid:8528597b-6a7c-4309-9a54-39c49a589ca9","http://resolver.tudelft.nl/uuid:8528597b-6a7c-4309-9a54-39c49a589ca9","Crumpling-based soft metamaterials: The effects of sheet pore size and porosity","Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics; Politecnico di Milano); Habibi, M. (Wageningen University & Research); Janbaz, S. (TU Delft Biomaterials & Tissue Biomechanics); Vergani, L. (Politecnico di Milano); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","Crumpled-based materials are relatively easy to fabricate and show robust mechanical properties for practical applications, including meta-biomaterials design aimed for improved tissue regeneration. For such requests, however, the structure needs to be porous. We introduce a crumpled holey thin sheet as a robust bio-metamaterial and measure the mechanical response of a crumpled holey thin Mylar sheet as a function of the hole size and hole area fraction. We also study the formation of patterns of crease lines and ridges. The area fraction largely dominated the crumpling mechanism. We also show, the crumpling exponents slightly increases with increasing the hole area fraction and the total perimeter of the holes. Finally, hole edges were found to limit and guide the propagation of crease lines and ridges.","Biomedical engineering; Materials for devices; Soft materials; Structural materials; OA-Fund TU Delft","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b88303a7-fbde-4ed4-af58-d9ab9a8e772b","http://resolver.tudelft.nl/uuid:b88303a7-fbde-4ed4-af58-d9ab9a8e772b","Review of techniques to achieve optical surface cleanliness and their potential application to surgical endoscopes","Kreeft (student), Davey; Arkenbout, E.A. (TU Delft Medical Instruments & Bio-Inspired Technology); Henselmans, P.W.J. (TU Delft Medical Instruments & Bio-Inspired Technology); Van Furth, Wouter R. (Leiden University Medical Center); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2017","A clear visualization of the operative field is of critical importance in endoscopic surgery. During surgery the endoscope lens can get fouled by body fluids (eg, blood), ground substance, rinsing fluid, bone dust, or smoke plumes, resulting in visual impairment. As a result, surgeons spend part of the procedure on intermittent cleaning of the endoscope lens. Current cleaning methods that rely on manual wiping or a lens irrigation system are still far from ideal, leading to longer procedure times, dirtying of the surgical site, and reduced visual acuity, potentially reducing patient safety. With the goal of finding a solution to these issues, a literature review was conducted to identify and categorize existing techniques capable of achieving optically clean surfaces, and to show which techniques can potentially be implemented in surgical practice. The review found that the most promising method for achieving surface cleanliness consists of a hybrid solution, namely, that of a hydrophilic or hydrophobic coating on the endoscope lens and the use of the existing lens irrigation system.","biomedical engineering; flexible endoscopy; gynecologic laparoscopy; interventional endoscopy; neurosurgery; NOTES; SILS; single-site surgery","en","review","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:1b0841b5-f6a6-4750-8490-0e83e8347c10","http://resolver.tudelft.nl/uuid:1b0841b5-f6a6-4750-8490-0e83e8347c10","A Fully Automated Chain from MDAO Problem Formulation to Workflow Execution","van Gent, I. (TU Delft Flight Performance and Propulsion); Lombardi, R. (NOESIS Solutions); la Rocca, G. (TU Delft Flight Performance and Propulsion); d'Ippolito, R (NOESIS Solutions)","","2017","In this paper, a methodology to connect the multidisciplinary design analysis and optimization (MDAO) problem formulation tool KADMOS and the commercial Process Integration and Design Optimization (PIDO) platform Optimus is presented. This capability has been developed in the context of the EU project AGILE. The aim of this development is to create a combined environment that gives the MDAO design team the ability to define and formalize an MDAO
problem and directly execute it with ease, without the need of the otherwise needed manual operations typically required to define the workflow in the PIDO system. The combination of problem formulation and PIDO platform execution have been tested on a small analytical MDAO problem to demonstrate its viability. Furthermore, a realistic aerostructural MDAO system of industrial relevance was also used to demonstrate the scalability of the approach for a bigger and more complex MDAO system. Results indicate that a fully automated chain is indeed possible which will make it easier for design teams to define, execute and compare different MDAO problem definitions and architectures in the time usually necessary to implement one MDAO system. Future work will focus on extending the proven capabilities of the automated chain to a wider variety of design problems and MDAO architectures.","MDO; MDAO; Design automation; PIDO; Systems Engineering; KADMOS; CMDOWS; Optimus","en","conference paper","","","","","","","","","","","Flight Performance and Propulsion","","",""
"uuid:a60e28a9-723e-4044-8677-4782f89719dd","http://resolver.tudelft.nl/uuid:a60e28a9-723e-4044-8677-4782f89719dd","The influence of freeze–thaw cycles on the shear strength of illite clay","Steiner, A.; Vardon, P.J. (TU Delft Geo-engineering); Broere, W. (TU Delft Geo-engineering)","","2017","Geo-energy infrastructure, such as ground source heat systems (thermo-active structures), induce thermal cycles that can result in changes of the bearing capacity of soil by changing, for example, the void ratio, soil structure, unit weight and hydraulic conductivity. The influence of repeated freeze/thaw (FT) cycles and different freezing rates on the shear strength of a frost susceptible Illite clay was investigated. Samples were subjected to between 1 and 20 FT cycles, and the shear strength of the thawed material was determined using undrained unconsolidated triaxial tests. After the shear strength decrease due to the first FT cycle, a transitory shear strength recovery occurred between 1 and 3 freezing cycles, followed by a shear strength decrease between 3 and 7 FT cycles, which then approached an equilibrium value. CT scans showed ice lenses increased in size moving away from the freezing surface, and more uniform ice distribution with increasing FT cycles. Changing the freezing rate yielded differences in the formation and structure of ice lenses perpendicular to the freezing direction. The observed failure plane typically coincides with the plane of the largest ice lens due to formation of a slurry layer after thawing.","geotechnical engineering strength; testing of materials thermal effects","en","journal article","","","","","","","","2019-02-10","","","Geo-engineering","","",""
"uuid:df47a578-cc35-4f7c-ba5e-927aad945659","http://resolver.tudelft.nl/uuid:df47a578-cc35-4f7c-ba5e-927aad945659","Thermoluminescence as a Research Tool to Investigate Luminescence Mechanisms","bos, A.J.J. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2017","Thermally stimulated luminescence (TSL) is known as a technique used in radiation dosimetry and dating. However, since the luminescence is very sensitive to the defects in a solid, it can also be used in material research. In this review, it is shown how TSL can be used as a research tool to investigate luminescent characteristics and underlying luminescent mechanisms. First, some basic characteristics and a theoretical background of the phenomenon are given. Next, methods and difficulties in extracting trapping parameters are addressed. Then, the instrumentation needed to measure the luminescence, both as a function of temperature and wavelength, is described. Finally, a series of very diverse examples is given to illustrate how TSL has been used in the determination of energy levels of defects, in the research of persistent luminescence phosphors, and in phenomena like band gap engineering, tunnelling, photosynthesis, and thermal quenching. It is concluded that in the field of luminescence spectroscopy, thermally stimulated luminescence has proven to be an experimental technique with unique properties to study defects in solids.","thermoluminescence; trap depth; energy level; rare earth ions; persistent luminescence; band gap engineering; tunnelling; photosynthesis; thermal quenching","en","journal article","","","","","","","","","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:4c154930-d6ec-493b-9800-5e9551fa6c49","http://resolver.tudelft.nl/uuid:4c154930-d6ec-493b-9800-5e9551fa6c49","Equilibrium running principle analysis on an adaptive cycle engine","Zheng, Junchao (Beihang University); Tang, Hailong (Beihang University); Chen, Min (Beihang University); Yin, F. (TU Delft Aircraft Noise and Climate Effects)","","2017","As an evolutional concept of variable cycle engine, the adaptive cycle engine draws widely attention with high expectations. It combines a variable geometry schedule and component matching principles to demonstrate its advantages such as avoiding severe inlet spillage drag and the wide variable cycle characteristics. Thus, this paper aims at equilibrium running principle analysis on an adaptive cycle engine at variable operating modes, deriving the equilibrium running equations of an adaptive cycle engine for the first time, and exploring the physical essence of components matching principle on the basis of a newly developed nonlinear component-based adaptive cycle engine performance model. It uncovers the physical essence of components matching relationships and provides mathematical derivation of equilibrium running principles which lay theoretical foundation of the variable geometries modulation schedule and overall performance optimization on an adaptive cycle engine.","Adaptive cycle engine; Components matching principle; Variable cycle engine; Overall performance","en","journal article","","","","","","","","","","","Aircraft Noise and Climate Effects","","",""
"uuid:76ccfb2d-0e95-44f2-9705-7d65de752446","http://resolver.tudelft.nl/uuid:76ccfb2d-0e95-44f2-9705-7d65de752446","Optimal control of EGR system in gasoline engine based on Gaussian process","Zarghami, M. (Ecole de Technologie Superieure (ETS)); Hassan HosseinNia, S. (TU Delft Mechatronic Systems Design); Babazadeh, M. (University of Zanjan)","","2017","The contribution described in this paper is concentrated on the integration of exhaust gas recirculation (EGR) system into the process of combustion in an optimal manner. In practice, deriving a state-space model of this actuator is an energetic task as a result of involving some uncertain chemical reactions. To alleviate the effect of unobserved phenomena, which does not seem to be easy in modeling, an improved Gaussian Process (GP) is represented for identifying such dynamics. In this approach, practical modification in general formulation of GP is provided based on proportional feedback gain adjustment. Afterwards, the obtained model is considered for design of optimal model-based control strategy. The whole aim is focused on achieving a green economically gasoline engine by optimizing the trend of fuel consumption. Eventually, simulation results illustrate the effectiveness of proposed structure in EGR systems.","Automotive engineering; Diesel engines; Fractional control; EGR valve; Gaussian Process","en","journal article","","","","","","","","","","","Mechatronic Systems Design","","",""
"uuid:6feb309b-c3a3-4495-99c2-1dd4468efb84","http://resolver.tudelft.nl/uuid:6feb309b-c3a3-4495-99c2-1dd4468efb84","Evolutionary engineering in chemostat cultures for improved maltotriose fermentation kinetics in saccharomyces pastorianus lager brewing yeast","Brickwedde, A. (TU Delft BT/Industriele Microbiologie); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Geertman, Jan Maarten A. (Heineken Supply Chain); Magalhães, Frederico (VTT Technical Research Center of Finland); Kuijpers, Niels G.A. (Heineken Supply Chain); Gibson, Brian (VTT Technical Research Center of Finland); Pronk, J.T. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie)","","2017","The lager brewing yeast Saccharomyces pastorianus, an interspecies hybrid of S. eubayanus and S. cerevisiae, ferments maltotriose, maltose, sucrose, glucose and fructose in wort to ethanol and carbon dioxide. Complete and timely conversion (""attenuation"") of maltotriose by industrial S. pastorianus strains is a key requirement for process intensification. This study explores a new evolutionary engineering strategy for improving maltotriose fermentation kinetics. Prolonged carbon-limited, anaerobic chemostat cultivation of the reference strain S. pastorianus CBS1483 on a maltotriose-enriched sugar mixture was used to select for spontaneous mutants with improved affinity for maltotriose. Evolved populations exhibited an up to 5-fold lower residual maltotriose concentration and a higher ethanol concentration than the parental strain. Uptake studies with 14C-labeled sugars revealed an up to 4.75-fold higher transport capacity for maltotriose in evolved strains. In laboratory batch cultures on wort, evolved strains showed improved attenuation and higher ethanol concentrations. These improvements were also observed in pilot fermentations at 1,000-L scale with high-gravity wort. Although the evolved strain exhibited multiple chromosomal copy number changes, analysis of beer made from pilot fermentations showed no negative effects on flavor compound profiles. These results demonstrate the potential of evolutionary engineering for strain improvement of hybrid, alloploid brewing strains.","Brewing; Chemostat; Evolutionary engineering; Maltose; Maltotriose consumption rate; Sacchromyces pastorianus; Transport; OA-Fund TU Delft","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:da98a321-fc15-4df8-bd83-e7d16ea1420a","http://resolver.tudelft.nl/uuid:da98a321-fc15-4df8-bd83-e7d16ea1420a","Elimination of sucrose transport and hydrolysis in Saccharomyces cerevisiae: a platform strain for engineering sucrose metabolism","Marques, W.L. (TU Delft BT/Industriele Microbiologie; University of Campinas); Mans, R. (TU Delft BT/Industriele Microbiologie); Marella, Eko Roy (Student TU Delft); Cordeiro, Rosa Lorizolla (University of Campinas); van den Broek, M.A. (TU Delft BT/Industriele Microbiologie); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Industriele Microbiologie); Gombert, Andreas K. (University of Campinas); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie)","","2017","Many relevant options to improve efficacy and kinetics of sucrose metabolism in Saccharomyces cerevisiae and, thereby, the economics of sucrose-based processes remain to be investigated. An essential first step is to identify all native sucrose-hydrolysing enzymes and sucrose transporters in this yeast, including those that can be activated by suppressor mutations in sucrose-negative strains. A strain in which all known sucrose-transporter genes (MAL11, MAL21, MAL31, MPH2, MPH3) were deleted did not grow on sucrose after 2 months of incubation. In contrast, a strain with deletions in genes encoding sucrose-hydrolysing enzymes (SUC2, MAL12, MAL22, MAL32) still grew on sucrose. Its specific growth rate increased from 0.08 to 0.25 h-1 after sequential batch cultivation. This increase was accompanied by a 3-fold increase of in vitro sucrose-hydrolysis and isomaltase activities, as well as by a 3- to 5-fold upregulation of the isomaltase-encoding genes IMA1 and IMA5. One-step Cas9-mediated deletion of all isomaltase-encoding genes (IMA1-5) completely abolished sucrose hydrolysis. Even after 2 months of incubation, the resulting strain did not grow on sucrose. This sucrose-negative strain can be used as a platform to test metabolic engineering strategies and for fundamental studies into sucrose hydrolysis or transport.","Disaccharide; Isomaltase; Laboratory evolution; Multiple gene deletion; Real-time PCR; Reverse engineering","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:78cbe7f1-c6dc-424d-9aea-92da3f263caf","http://resolver.tudelft.nl/uuid:78cbe7f1-c6dc-424d-9aea-92da3f263caf","Contributing human and organizational factors for damage of Bos and Lommer plaza in Amsterdam","Terwel, K.C. (TU Delft Applied Mechanics)","","2017","The Bos & Lommer plaza complex in Amsterdam was completed in 2004. This complex consisted of apartments, shops and a parking for over 500 cars. In 2006, an 11 ton truck was positioned on the plaza deck and caused structural damage. Part of the load bearing structure had failed and the apartments were evacuated, until the deck was strutted. Forensic investigations showed that detailing of the reinforcement was questionable and the amount of reinforcement was insufficient, or deviated from drawings. The whole complex was evacuated until measures were taken. Subsequently, investigations of the shops and apartments above the parking showed that the design of a 1 m thick transfer floor might have been erroneous. Profound investigation of this case showed various human and organizational factors, that might have contributed to the failure. The stacking of various functions resulted in a complex load bearing structure. The building process was complex with over 50 subcontractors. The safety culture was not well developed, given heavily economizing on costs and very tight planning, fragmentation and no clear final responsibility. Risk analysis and checking procedures were lacking. Communication and collaboration could have been improved. This paper will give insight in technical causes of the failure and in underlying contributing factors. These underlying factors will be systematically studied, by using a theoretical framework.","Forensic Structural Engineering; Failures; Human and organizational factors","en","conference paper","","","","","","","","2018-10-01","","","Applied Mechanics","","",""
"uuid:ccedae52-2933-4189-a121-10b1b4d8ab03","http://resolver.tudelft.nl/uuid:ccedae52-2933-4189-a121-10b1b4d8ab03","Saccharomyces cerevisiae strains tor second-generation ethanol production: from academie exploration to industrial implementation","Jansen, Mickel L.A. (DSM); Bracher, J.M. (TU Delft BT/Industriele Microbiologie); Papapetridis, I. (TU Delft BT/Industriele Microbiologie); Verhoeven, M.D. (TU Delft BT/Industriele Microbiologie); de Bruijn, J.A. (DSM); de Waal, P. (DSM); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie; AlbaNova University Center); Klaassen, P (DSM); Pronk, J.T. (TU Delft BT/Industriele Microbiologie)","","2017","The recent start-up of several full-scale ‘second generation’ ethanol plants marks a major milestone in the development of Saccharomyces cerevisiae strains for fermentation of lignocellulosic hydrolysates of agricultural residues and energy crops. After a discussion of the challenges that these novel industrial contexts impose on yeast strains, this minireview describes key metabolic engineering strategies that have been developed to address these challenges. Additionally, it outlines how proof-of-concept studies, often developed in academic settings, can be used for the development of robust strain platforms that meet the requirements for industrial application. Fermentation performance of current engineered industrial S. cerevisiae strains is no longer a bottleneck in efforts to achieve the projected outputs of the first large-scale second-generation ethanol plants. Academic and industrial yeast research will continue to strengthen the economic value position of second-generation ethanol production by further improving fermentation kinetics, product yield and cellular robustness under process conditions.","biofuels; metabolic engineering; ndustrial fermentation; yeast biotechnology; pentose fermentation; biomass hydrolysates","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:e8d991bd-7463-4a7b-b574-86efbd42db62","http://resolver.tudelft.nl/uuid:e8d991bd-7463-4a7b-b574-86efbd42db62","Investigation of Olympus TJF‐Q180V Scopes at UMC Utrecht regarding contamination found after cleaning and disinfection: Reporting, Conclusions and Suggestions","Loeve, A.J. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2017","In 2015, a multi-resistant Klebsiella pneumonia bacteria (“MR Klebsiella”) was found in two Olympus video duodenoscopes of the type TJF-Q180V in the Utrecht University Medical Center (“UMC Utrecht”) after the culturing of flush samples (sterile physiological saline), which were sent through the suction and biopsy channels. This report describes the extensive, and finally destructive investigation of the contaminated scopes that was conducted to reveal the potential causes of the persistent contamination. It appeared that improper maintenance by an external endoscope maintenance company was a major factor.","Forensic Engineering; Investigation; ERCP-scopes; Patient safety; Inspection; Health-care safety; Endoscopy; Infection; Medical technology; Medical device design","mul","report","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:587f54ef-8372-430e-8927-3b6cccda94a3","http://resolver.tudelft.nl/uuid:587f54ef-8372-430e-8927-3b6cccda94a3","More than just a Green Facade: The sound absorption properties of a vertical garden with and without plants","Davis, Michael (Pontificia Universidad Católica del Ecuador); Tenpierik, M.J. (TU Delft Building Physics); Ramirez, Francisco (Pontificia Universidad Católica del Ecuador); Perez, Maria Elena","","2017","Up to 44% of EU residents are exposed to noise levels that are detrimental to health. In this context, vertical gardens could play an important role in architectural acoustics, where the main absorber material is the substrate soil. Plants have a beneficial effect for higher frequencies when planted in a large density. In this paper a vertical garden design developed at the Pontificia Universidad Catolica of Ecuador (PUCE) was tested for interior acoustic design. The modules solely with substrate and planted with ferns were tested. The objective was to ascertain and explain the random incidence sound absorption coefficient of vertical garden modules. 50 modules making up a total floor area of 10.125 m2 were used for the measurements. Six different configurations were measured: connected versus dispersed and directly on the floor versus with an air cavity of 5 and 10 cm. Furthermore, each configuration was tested with modules solely filled with substrate and with substrate filled modules with densely planted ferns. The weighted random incidence sound absorption coefficient of the modules densely planted with ferns equals 1.00. This applied to all different configurations tested. The sound absorption coefficient in the lower frequencies (100-315 Hz), mid frequencies (400e1250 Hz) and high frequencies (1600-5000 Hz) was 0.59-0.80, 1.00 and 1.00 respectively. This makes this type of building technology highly suitable for applications where sound needs to be attenuated, paving the way for applying vertical garden systems as a design tool for improving the acoustics of indoor spaces or urban squares.","Vertical gardens; Acoustics; Architecture; Sound engineering; Sustainable design; Urban ecology","en","journal article","","","","","","Accepted Author Manuscript","","2019-01-11","","","Building Physics","","",""
"uuid:0a023bf1-b4ea-4bb9-b63f-3e7880625e28","http://resolver.tudelft.nl/uuid:0a023bf1-b4ea-4bb9-b63f-3e7880625e28","Proceedings of the PowerSkin Conference: January 19th 2017, Munich","","Auer, Thomas (editor); Knaack, U. (editor); Schneider, Jens (editor)","2017","The Building Skin has evolved enormously over the past decades. Energy performance and environmental quality of buildings are significantly determined by the building envelope. The façade has experienced a change in its role as an adaptive climate control system that leverages the synergies between form, material, mechanical and energy systems in an integrated design.
The PowerSkin Conference aims to address the role of building skins to accomplish a carbon neutral building stock. Topics such as building operation, embodied energy, energy generation and storage in context of façades, structure and environment are considered.
Three main themes will be showcased in presentations of recent scientific research and developments as well as projects related to building skins from the
perspectives of material, technology and design:
Environment – Façades or elements of façades which aim for the provision of highly comfortable surroundings where environmental control strategies as well as energy generation and/or storage are integral part of an active skin.
Façade Design – The building envelope as an interface for the interaction between indoor and outdoor environment. This topic is focused on function and energy performance, technical development and material properties.
Façade Engineering – New concepts, accomplished projects, and visions for the interaction between building structure, envelope and energy technologies.","Environment; Façade Design; Façade Engineering","en","book","TU Delft OPEN Publishing","978-94-92516-29-9","","","","","","","","","Design of Constrution","","",""
"uuid:e373d4cc-67ed-4532-aa8f-bfc70af7771c","http://resolver.tudelft.nl/uuid:e373d4cc-67ed-4532-aa8f-bfc70af7771c","Strategic competences for concrete action towards sustainability: An oxymoron? Engineering education for a sustainable future","Mulder, K.F. (TU Delft Environmental Technology and Design; The Hague University of Applied Sciences)","","2017","In the current discourses on sustainable development, one can discern two main intellectual cultures: an analytic one focusing on measuring problems and prioritizing measures, (Life Cycle Analysis (LCA), Mass Flow Analysis (MFA), etc.) and; a policy/management one, focusing on long term change, change incentives, and stakeholder management (Transitions/niches, Environmental economy, Cleaner production).These cultures do not often interact and interactions are often negative. However, both cultures are required to work towards sustainability solutions: problems should be thoroughly identified and quantified, options for large change should be guideposts for action, and incentives should be created, stakeholders should be enabled to participate and their values and interests should be included in the change process. The paper deals especially with engineering education. Successful technological change processes should be supported by engineers who have acquired strategic competences. An important barrier towards training academics with these competences is the strong disciplinarism of higher education. Raising engineering students in strong disciplinary paradigms is probably responsible for their diminishing public engagement over the course of their studies. Strategic competences are crucial to keep students engaged and train them to implement long term sustainable solutions.","Engineering culture; Engineering education; Interdisciplinarity; Paradigm; Strategic competences; Transitions","en","journal article","","","","","","","","","","","Environmental Technology and Design","","",""
"uuid:c751c1b3-06de-463e-971f-db9948f1c17a","http://resolver.tudelft.nl/uuid:c751c1b3-06de-463e-971f-db9948f1c17a","Model-based systems engineering to design collaborative robotics applications","Hernández, Carlos (TU Delft Robot Dynamics); Fernandez-Sanchez, Jose Luis (Universidad Politécnica de Madrid)","Rassa, Bob (editor); Carbone, Paolo (editor)","2017","Novel robot technologies are becoming available to automate more complex tasks, more flexibly, and collaborating with humans. Methods and tools are needed in the automation and robotics industry to develop and integrate this new breed of robotic systems. In this paper, the ISE&PPOOA methodology for Model-Based Systems Engineering is applied for the development of robotic systems. The methodology is described through its application to reengineer a state-of-the-art collaborative robot application. The challenges that robotic systems present to model-based systems engineering are discussed, together with the benefits of MBSE methodologies.","Service robots; Collaboration; Safety; Systems engineering and theory; Collision avoidance; Computer architecture","en","conference paper","IEEE","","","","","Accepted Author Manuscript","","","","","Robot Dynamics","","",""
"uuid:b5cd3624-59af-4b65-864f-d26220c9f281","http://resolver.tudelft.nl/uuid:b5cd3624-59af-4b65-864f-d26220c9f281","Surpassing the Carnot efficiency by extracting imperfect work","Ng, N.H.Y. (TU Delft Quantum Information and Software; TU Delft QuTech Advanced Research Centre; National University of Singapore); Woods, M.P. (TU Delft QID/Wehner Group; TU Delft QuTech Advanced Research Centre; University College London (UCL)); Wehner, S.D.C. (TU Delft Quantum Internet Division; TU Delft Quantum Information and Software; TU Delft QuTech Advanced Research Centre; National University of Singapore)","","2017","A suitable way of quantifying work for microscopic quantum systems has been constantly debated in the field of quantum thermodynamics. One natural approach is to measure the average increase in energy of an ancillary system, called the battery, after a work extraction protocol. The quality of energy extracted is usually argued to be good by quantifying higher moments of the energy distribution, or by restricting the amount of entropy to be low. This limits the amount of heat contribution to the energy extracted, but does not completely prevent it. We show that the definition of 'work' is crucial. If one allows for a definition of work that tolerates a non-negligible entropy increase in the battery, then a small scale heat engine can possibly exceed the Carnot efficiency. This can be done without using any additional resources such as coherence or correlations, and furthermore can be achieved even when one of the heat baths is finite in size.","quantum heat engines; quantum thermodynamics; single-shot work extraction; thermodynamic resource theories","en","journal article","","","","","","","","","","Quantum Internet Division","Quantum Information and Software","","",""
"uuid:efb45c8d-e8a2-4840-8aa5-a6fd5f4999f0","http://resolver.tudelft.nl/uuid:efb45c8d-e8a2-4840-8aa5-a6fd5f4999f0","Toward Bio-based geo- & Civil Engineering for a Sustainable Society","Jonkers, H.M. (TU Delft Materials and Environment)","","2017","The since 2010 running research program 'Bio-Based Geo & Civil Engineering for a Sustainable Society (BioGeoCivil)', funded by the Dutch technology foundation STW, aims to develop novel bio-based construction materials that can be used in Civil- and Geo-engineering constructions to enhance the sustainability performance of the sector. Rationale is that the sector produces still today excess amounts of waste in all life cycle phases of a construction, from building to use phase as well as end-of-life phase. Aim of the program is to mimic nature as 'building' processes in nature do not produce any waste as all elements, also residual material. is considered a high grade resource. In order to substantially improve the sustainability profile of the sector, upgrading of secondary- or byproducts must be achieved to allow functional performance similar to primary materials and resources. The challenge of the six currently running projects within the BioGeoCivil program is therefore not only to mimic nature but also to include bio-based materials or processes in civil- or geo-engineering applications which result, in comparison to traditional building products, in drastically improved performance both on sustainability and durability level. The six projects comprise: 1. Fungal biofilms (coating) for wood protection, 2. Bacteria-based repair and performance improvements of aged concrete structures, 3. Bacteria-based ground stabilization to mitigate liquefaction and piping of granular sediments, 4. Engineering of bacterial biofilms on buildings and infrastructure as a basis for natural protection, 5. Lift up Lowlands: upgrading of natural materials (bio-remediation of sludge) for sustainable lift up of low lying polder areas, and 6. Towards the development of carbon dioxide neutral renewable cement.","Bio-based processes; cement; civil- and geo-engineering; concrete; soil","en","journal article","","","","","","","","","","","Materials and Environment","","",""
"uuid:08d5dfea-2dfb-46ad-ab44-afb137e12800","http://resolver.tudelft.nl/uuid:08d5dfea-2dfb-46ad-ab44-afb137e12800","Estimation of the dynamic response of a slender suspension bridge using measured acceleration data","Petersen, Øyvind Wiig (Norwegian University of Science and Technology (NTNU)); Øiseth, Ole (Norwegian University of Science and Technology (NTNU)); Lourens, E. (TU Delft Offshore Engineering)","Vestroni, Fabrizio (editor); Gattulli, Vincenzo (editor); Romeo, Francesco (editor)","2017","Suspension bridges with very long spans and slender designs are susceptible to large-amplitude dynamic excitation. Monitoring systems installed on bridges can provide measurement data (e.g. accelerations) and therewith valuable information on the true dynamic behaviour. This pilot study examines the possible use of recently developed methods for real-time response estimation at unmeasured locations. The methodology for response estimation is tested in a case study on the Hardanger Bridge, a 1310 m long suspension bridge in Norway, which has a network of twenty accelerometers. Two techniques, a joint input-state estimation algorithm (JIS) and a dual Kalman filter (DKF), are used to estimate the full-field dynamic response using data measured at the bridge and a reduced order structural model. The results show that the DKF is able to estimate accelerations fairly accurately. The JIS estimate, however, suffer from ill-conditioning and consequently show severe errors. Possible reasons for this ill-conditioning are briefly discussed.","response estimation; structural monitoring; suspension bridge; wind engineering","en","conference paper","Elsevier","","","","","","","","","","Offshore Engineering","","",""
"uuid:561ca1ec-3dfe-4768-955a-51a938b473d3","http://resolver.tudelft.nl/uuid:561ca1ec-3dfe-4768-955a-51a938b473d3","Application of a second-order implicit material point method","Burg, M (Plaxis); Lim, L.J. (Plaxis); Brinkgreve, R.B.J. (TU Delft Geo-engineering; Plaxis)","Rohe, Alexander (editor); Soga, Kenichi (editor); Teunissen, Hans (editor); Zuada Coelho, Bruno (editor)","2017","In this work, we present the application of a newly developed implicit second-order Material Point Method (MPM) on offshore geotechnical applications. The presented second-order MPM uses a special set of piecewise quadratic shape functions to circumvent the well-known issue of producing zero nodal mass contributions. To mitigate the effect of the standard MPM to produce highly oscillating stresses across cell interfaces, we have carried over our ideas obtained from the derivation of the second-order MPM to the Dual Domain Material Point (DDMP) Method, too. The resulting second-order DDMP Method produces a smoother stress distribution across the entire computational domain while being able to profit from the improved convergence rates of second-order finite elements. In a numerical example from geotechnical engineering applications, we illustrate the practical application of our enhanced Material Point and DDMP Methods by simulating a cone penetration.","material point method; DDMP; large deformations; particle-in-cell method; offshore geotechnical engineering","en","conference paper","Elsevier","","","","","","","","","","Geo-engineering","","",""
"uuid:2ca107b4-202d-4638-a044-d45649b89275","http://resolver.tudelft.nl/uuid:2ca107b4-202d-4638-a044-d45649b89275","Automatic 3D Routing for the Physical Design of Electrical Wiring Interconnection Systems for Aircraft","Zhu, Z. (TU Delft Flight Performance and Propulsion)","la Rocca, G. (promotor); van Tooren, Michel (promotor); Delft University of Technology (degree granting institution)","2016","Harness 3D routing is one of the most challenging steps in the design of aircraft Electrical Wiring Interconnection System (EWIS), due to the intrinsic complexity of the EWIS, the increasing number of applying design constraints, and its dependency on the design changes of the airframe and installed systems. The current routing process employed by EWIS design is largely based on the manual work of expert engineers, partially supported by conventional CAD systems. As a result, the routing process is quite inefficient, error prone and unable to deliver optimal solutions. Although many harness components are selected from catalogues and the design process is largely repetitive and rule based, it has been found that none or very limited automation solutions, which can significantly decrease the workload of engineers and increase their efficiency, are currently available. In this research, an innovative approach is proposed to solve the 3D routing automation as an optimization problem. Knowledge Based Engineering (KBE) and optimization methods are proposed to achieve the minimum cost routing solutions that satisfy all relevant design rules and constraints.
The basic idea is to achieve the optimal EWIS routing solutions by optimizing the position of the harnesses clamping points, which are used as way-points to route the harnesses inside the aircraft digital mock-up. The challenge to solve this optimization problem is that the number and initial value of design variables, namely the number and position of clamping points, are not known a priori. In order to handle this challenge, a two-step, hybrid optimization strategy has been devised. The first step, called Initialization, uses a road map based path finding method to generate a preliminary harness definition, including the required number and preliminary position of its clamping points. The second step, called Refinement, uses a conventional optimization method to move the position of the clamps and refine the preliminary harness definition aiming for the minimum cost and the satisfaction of all the design constraints. This approach has been implemented into a KBE application and tested on several routing cases. The results demonstrate that the proposed method is capable of handling cases of representative geometric complexity and design constraints and delivering proper 3D harness models in full automation.
The conventional approach of increasing Bypass Ratio (BPR), Overall Pressure Ratio (OPR), and Turbine Inlet Temperature (TIT) to improve the cycle efficiency, and thereby reducing the fossil fuel consumption and the associated emissions is unlikely to meet the ACARE goals. Moreover, the high OPR and TIT aggravate the NOx emissions for a given combustion technique. A novel multi-fuel hybrid engine for a Multi-Fuel Blended Wing Body (MFBWB) aircraft conceived in the “Advanced Hybrid Engine for Aircraft Development (AHEAD)” project brings to light promising solutions in this regard.
The multi-fuel hybrid engine is a turbofan engine with the following added components: a Contra-Rotating Fans (CRF) system, two sequential combustors burning different fuels simultaneously, and a Cryogenic Bleed Air Cooling System (CBACS). The CRF can sustain the non-uniform flow ingested from the boundary layer of the airframe. The first combustor is the main combustor, where the Liquid Hydrogen (LH2) or the Liquid Natural Gas (LNG) is burnt to reduce CO2. The second combustor, Interstage Turbine Burner (ITB), is located between the high pressure and the low pressure turbine burning kerosene or biofuel in a Flameless Combustion (FC) mode. With the thermal energy provided by different fuel sources, the volume required to store cryogenic fuels is less; meanwhile, the FC technique is beneficial to reduce NOx. By introducing the CBACS, LH2 or LNG is used as a coolant to cool down the bleed air.
According to fuel combinations, the hybrid engine is classified as LNG-kerosene version and LH2-kerosene version, where kerosene might be replaced by biofuel. By defining an “ITB energy fraction” as the ratio of the energy input of the ITB to the overall energy consumed, the fuel flow rates of two combustors are controlled. Using the developed model framework, the characteristics of the hybrid engine are studied and summarized in the following three aspects:
Potentials of the ITB engine cycle:
The sequential combustor configuration of the hybrid engine forms a reheat cycle. By distributing the energy into two combustors, the heat addition to each combustor decreases; therefore, the TIT is lower. Consequently, the turbine cooling air and the associated loss in the turbine efficiency reduces. Moreover, the NOx produced from the upstream combustor dissociates again in the ITB, which helps to lower the overall NOx emissions. These remarkable features are appreciable when the OPR and BPR are forced to continuously increase, which causes a substantial increase in the TIT of a classical engine. A turbine with very high inlet temperature has to be cooled substantially. Eventually, the gain in cycle efficiency might be canceled by the loss in the turbine efficiency. Moreover, when the TIT is increased beyond 1800 K, the NOx exhibits an exponential increase. Hence following the evolution of the engine technology, the reheat cycle would be an option for the next step.
Characteristics of the multi-fuel hybrid engine:
The features of the hybrid engine have been explored from various aspects. The isobaric heat capacity of the combustion products from LNG and LH2 is higher than that from kerosene, which is beneficial to the thermal efficiency. Using LNG and LH2 as a coolant, the bleed air temperature reduces substantially (maximum by more than 500 K), thereby, the turbine cooling air mass flow rate decreases by half. Moreover, the increase in fuel temperature is favourable to enhance the thermal efficiency. The hybrid engine has been optimized at cruise considering various ITB energy fractions. The optimized engine cycle is verified at critical operating points. The assessment of the standalone engine performance with baseline engines shows that the LH2-kerosene hybrid engine is superior to the LNG-kerosene hybrid engine in terms of the cycle efficiency and the CO2 reduction. However, the mission analysis shows conflicting results. Due to the stronger installation effect, the MFBWB together with the LH2-kerosene hybrid engine scores lower, implying that the LNG-kerosene BWB would have the least climate impact.
Operating strategy of the multi-fuel hybrid engine:
The operating strategy of the hybrid combustion system has been developed to enhance the steady state performance of the hybrid engine. The analysis exhibits that using an ITB is beneficial for the high pressure spool speed, the HPC exit temperature, and the HPT inlet temperature. However, the LPC surge margin and LPT inlet temperature conflict their limits as the ITB energy fraction increases. For the various thrust requirements at Sea Level Static (SLS) standard condition, a fuel control schedule together with a variable bleed valve schedule is proposed. Moreover, another fuel control strategy is suggested for the flat rating at SLS.
Within the cases we analyzed, MCR in Chromium addresses security issues at a rate of 1% of reviewers’ comments. Chromium code reviews mostly tend to miss language-specific issues (e.g., C++ issues and buffer overflows) and domain-specific ones (e.g., such as Cross-Site Scripting); when code reviews address issues, mostly they address those that pertain to the latter type. Initial evidence points to reviews conducted by more than 2 reviewers being more successful at finding security issues.","Code review; Empirical software engineering; Mining software repositories; Modern code review; Security flaw; Software security","en","conference paper","IEEE","","","","","Acknowledgments: European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642954","","","","","Software Engineering","","",""
"uuid:d784840c-2d6a-4cdf-b193-3ad58a54077c","http://resolver.tudelft.nl/uuid:d784840c-2d6a-4cdf-b193-3ad58a54077c","Safety: A system state or property?","Stoop, J.A.A.M. (Kindunos Safety Consultancy)","","2016","Safety is frequently addressed as an emergent property of complex and dynamic systems. This contribution advocates the validity and importance of incorporating intrinsic technological hazards and systemic interrelations from a multi-actor perspective in the early phases of design and development. This perspective creates inherent properties in various system states, which may manifest themselves as emergent properties during operations. These safety properties are based on their business models, selectively focusing on primary system components such as infrastructure, vehicles or traffic management. Experiences with major aviation and railway projects highlight the potential of engineering design approaches such as multidisciplinary design optimization, value engineering and vectorial state/space modelling. Such an approach has high change potential for a specific category of high energy density complex socio-technical systems","safety; systems engineering design; emergent properties; railways; aviation","en","journal article","","","","","","","","","","","","","",""
"uuid:ac50143e-5ccb-49a5-bb9d-7cb9a93bb30e","http://resolver.tudelft.nl/uuid:ac50143e-5ccb-49a5-bb9d-7cb9a93bb30e","Reverse engineering of free form shell structures: From point cloud to finite element model","Eigenraam, P. (TU Delft Structural Design & Mechanics); Borgart, A. (TU Delft Structural Design & Mechanics)","","2016","Many free form shell structures that have been designed and build in previous decades are fascinating structures. We can learn from these structures by analysing them and studying their structural behaviour. However, in some cases the geometry of these structures is not available; most notably the shapes of shell structures designed and build by Heinz Isler, who has built over 1400 shells. The geometry of many of his scale models and build structures have been obtained by the authors by making use of 3D laser scanners which create point clouds.
This paper presents a method for reverse engineering of free form shell structures from point cloud to finite element model. Since shape and force interact, special attention is given to the geometric accuracy. Every model must be sufficiently accurate. The method has been applied to data obtained by scanning Isler’s shells. Important aspects that influence the quality of the resulting finite element model are described.","Reverse engineering; shell structures; point cloud; finite element analysis; mesh","en","journal article","","","","","","","","","","","Structural Design & Mechanics","","",""
"uuid:4fd2f0f1-5d00-4978-8f9c-27a773e093c1","http://resolver.tudelft.nl/uuid:4fd2f0f1-5d00-4978-8f9c-27a773e093c1","Dialogue hydraulic engineering and spatial design","Voorendt, M.Z. (TU Delft Hydraulic Structures and Flood Risk)","Nillesen, Anne Loes (editor); Kothuis, Baukje (editor); Meyer, Han (editor); Palmboom, Frits (editor)","2016","In practice, the disciplines of landscape architecture/urbanism and hydraulic engineering have become more specialized during the last decades, gradually growing apart. The gap between governance and ecology seems to have become even larger. This leads to discussions about who should take the lead in a design; and, if the design approach is not fully integrated, this can lead to sub-optimal systems. This could lead to less societal acceptance of the solution, as well as to inefficient use of financial resources. Recent initiatives at the Delft University of Technology aim to bridge this gap.","engineering design; spatial design; flood risk","en","book chapter","","","","","","","","","","","Hydraulic Structures and Flood Risk","","",""
"uuid:298e937a-7b26-4948-9ca6-30c68a3ac3a8","http://resolver.tudelft.nl/uuid:298e937a-7b26-4948-9ca6-30c68a3ac3a8","Ethics and the UN Sustainable Development Goals: The Case for Comprehensive Engineering: Commentary on “Using Student Engagement to Relocate Ethics to the Core of the Engineering Curriculum”","van den Hoven, M.J. (TU Delft Values Technology and Innovation)","","2016","In the twenty-first century, the urgent problems the world is facing (the UN Sustainable Development Goals) are increasingly related to vast and intricate ‘systems of systems’, which comprise both socio-technical and eco-systems. In order for engineers to adequately and responsibly respond to these problems, they cannot focus on only one technical or any other aspect in isolation, but must adopt a wider and multidisciplinary perspective of these systems, including an ethical and social perspective. Engineering curricula should therefore focus on what we call ‘comprehensive engineering’. Comprehensive engineering implies ethical coherence, consilience of scientific disciplines, and cooperation between parties.","Comprehensive engineering; Engineering ethics; Global systems science; Responsible research and innovation; Sustainable development; Sustainable development goals","en","journal article","","","","","","","","","","Values Technology and Innovation","","","",""
"uuid:d24f1865-380d-414a-bbc9-1a36f8beb699","http://resolver.tudelft.nl/uuid:d24f1865-380d-414a-bbc9-1a36f8beb699","Smart reading aid for detecting problems with reading fluency and comprehension","Rusak, Z. (TU Delft Cyber-Physical Systems); van de Water, Niels (External organisation); Horvath, I. (TU Delft Cyber-Physical Systems); de Smit, A. (TU Delft Technical Support); van der Vegte, Wilhelm Frederik (TU Delft Cyber-Physical Systems)","","2016","Brain signal and eye tracking technology have been intensively applied in cognitive science in order to study reading, listening and learning processes. Though promising results have been found in laboratory experiments, there are no smart reading aids that are capable to estimate difficulty during normal reading. This paper presents a new concept that aims to tackle this challenge. Based on a literature study and an experiment, we have identified several indicators for characterizing word processing difficulty by interpreting electroencelography (EEG) and electrooculography (EOG) signals. We have defined a computational model based on fuzzy set theory, which estimates the probability of word processing and comprehension difficulty during normal reading. The paper also presents a concept and functional prototype of a smart reading aid, which is used to demonstrate the feasibility of our solution. The results of our research proves that it is possible to implement a smart reading aid that is capable to detect reading difficulty in real time. We show that the most reliable indicators are related to eye movement (i.e. fixation and regression), while brain signals are less dependable sources for indicating word processing difficulty during continuous reading.","Engineering prototypes; Brain; Electroencephalography; Fuzzy set theory; Probability; Signals","en","conference paper","ASME","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2017-02-21","","","Cyber-Physical Systems","","",""
"uuid:1402a506-c044-4155-8f98-2ab46af16502","http://resolver.tudelft.nl/uuid:1402a506-c044-4155-8f98-2ab46af16502","Hands on Workshop on Teaching Forensic Engineering Teaching Students Critical Thinking by Investigative mindset","Saunders-Smits, Gillian (TU Delft Aerospace Structures & Computational Mechanics); Schuurman, M.J. (TU Delft Structural Integrity & Composites); Rans, C.D. (TU Delft Structural Integrity & Composites)","","2016","When teaching Engineering to students it is important that we not only teach about
how to engineer new things but also look at the failures and performance problems
from an engineering point-of-view. The field that studies this part of engineering is
known as Forensic Engineering. The American Society of Civil Engineers defines this
field as: “The application of engineering principles to the investigation of failures or
other performance problems. Forensic engineering also involves testimony on the
findings of these investigations before a court of law or other judicial forum, when
required","Forensic Engineering Education; Aerospace Engineering Education; Learning-by-Doing; Critical Thinking","en","conference paper","","","","","","","","","","","Aerospace Structures & Computational Mechanics","","",""
"uuid:adf65660-eee4-4a27-a21d-240601c83062","http://resolver.tudelft.nl/uuid:adf65660-eee4-4a27-a21d-240601c83062","Potential of Hardware-in-the-Loop simulation in the towing tank","Vrijdag, A. (TU Delft Ship Design, Production and Operations)","Farr, S. (editor); Zande, J. (editor); Kirkwood, B. (editor)","2016","Traditionally, model scale tests of ships are carried out without taking into account the dynamics of the shipboard systems that are involved in the operation under consideration. An example of this is the way that model scale free sailing tests in waves are carried out. The ship model is mounted with an electric motor, shaft and propeller and subsequently tests are carried out with constant propeller speed. In some cases constant shaft torque or constant power are employed. However, neither of these options reflects realistic behaviour of the drive system, because in waves and during manoeuvres the propeller speed, torque and power are in fact variable and their dynamic behaviour is governed by the drive train characteristics. The question arises to what extent, and in which cases, the dynamics of the shipboard systems affect the overall system behaviour. In this paper the application of Hardware-in-the-Loop (HIL) simulation in a ship model basin or towing tank is explored as a means to answering that question. The ambition is to develop an instrumented model scale ship of which the components of the drive train and its control are included by means of a correctly scaled time domain computer simulation model of the propulsion system. This simulation model is to run on a real-time processor which, via IO cards, provides electric power to an electric motor on-board the instrumented model scale ship, which in turn drives one or multiple shafts and propulsors. In this paper the role of scale effects on the test set-up is discussed. It is also shown that, in order to simulate realistic drive train dynamics in waves and during manoeuvres, it must be ensured that the combination of partial simulated drive train on the one hand and electric motor dynamics plus shaft and propeller inertia on the other hand should, as a total, represent the real dynamics of the drive train system.","Computational modeling; Marine vehicles; Propellers; Torque; Shafts; Engines","en","conference paper","IEEE","","","","","Accepted Author Manuscript","","","","","Ship Design, Production and Operations","","",""
"uuid:b672f050-af2a-4b94-88e3-eedcf73878ea","http://resolver.tudelft.nl/uuid:b672f050-af2a-4b94-88e3-eedcf73878ea","Forensic Structural Engineering in education","Terwel, K.C. (TU Delft Steel & Composite Structures; Coenraedt B.V.); Hordijk, D.A. (TU Delft Steel & Composite Structures; Adviesbureau ir. J.G. Hageman)","","2016","Forensic Structural Engineering is the professional practice of determining the cause(s) of a structural failure, often with the aim to lay out a technical basis to identify the responsible parties for a failure. Although Forensic Structural Engineering is given as course at several universities in USA and UK, at many institutions it is no common practice to include it in the civil engineering curricula. At TU Delft a graduate course has been initiated for building and structural engineering students, starting from September 2015. The course needs to meet a two-fold aim: 1. To understand and explain important structural failure mechanisms in various materials 2. To come up with design measures to avoid these problems This paper describes how this course was successfully implemented in the civil engineering curriculum.","Forensic Structural Engineering; Education; Blended learning; Failures","en","conference paper","","","","","","","","","","","Steel & Composite Structures","","",""
"uuid:1ed22666-83f5-42e9-815c-2cd80358dc44","http://resolver.tudelft.nl/uuid:1ed22666-83f5-42e9-815c-2cd80358dc44","The relation between well spacing and Net Present Value in fluvial Hot Sedimentary Aquifer geothermal doublets: a West Netherlands Basin case study","Willems, C.J.L. (TU Delft Reservoir Engineering); Goense, T. (TU Delft Reservoir Engineering); Nick, H.M. (TU Delft Reservoir Engineering); Bruhn, D.F. (TU Delft Reservoir Engineering)","","2016","This paper analyzes the relation between well spacing and Net Present Value of a Hot Sedimentary Aquifer geothermal doublet. First, a sensitivity analysis is carried out to evaluate the effect of uncertainty of geological and production parameters on the Net present Value. Second a finite-element approach is utilized to study the effect of fluvial facies architecture on geothermal energy production. For this purpose detailed fluvial facies architecture models are created utilizing a process-based facies modelling approach. These models and reservoir properties are based on a geological dataset of the Lower Cretaceous Nieuwerkerk Formation in the West Netherlands Basin (WNB). Results of the sensitivity analysis show that a 10% variation in well spacing from a 1000m base case scenario could vary the NPV by 10%. The minimal required well spacing is dependent on the reservoir thickness, flow rate and the allowed production temperature drop. The simulations results show that the theoretical advantage of a reduction in well spacing could be balanced by a poor well connectivity between the wells because of the characteristic of fluvial reservoir architecture.","Hot Sedimentary Aquifers; Net Present Value; West Netherlands Basin; Direct Use; Reservoir Engineering","en","conference paper","","","","","","","","","","","Reservoir Engineering","","",""
"uuid:d34b83ec-74b1-4176-bdba-035724f5b69a","http://resolver.tudelft.nl/uuid:d34b83ec-74b1-4176-bdba-035724f5b69a","Realizing Steady Supply to a Treatment Plant from Multiple Sources","van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (Aronwis)","","2016","In sewer systems sewage from different areas is often treated in a shared Waste Water Treatment Plant (WWTP). Currently the flows from different areas are usually determined by needs local to that area. During dry weather this may result in large variations in the flow into the WWTP. There are two reasons why this may be undesirable. Due to design peculiarities of some WWTP’s this may disrupt the treatment process and necessitate the use of additional energy and chemicals. In other cases areas are connected to the same pressurized transport pipe line, so energy costs may be higher when multiple stations use the line at the same time. Due to the daily variation in the sewage flow from domestic and light industrial sources, limits on temporary in system storage and due to limitations on the range of discharges the pumps can deliver, minimizing the flow variations can be a complex problem. Under the assumption of a periodic inflow sufficient conditions for the existence of a solution are given. The conditions imply the existence of a repeatable pattern of a length less than a day.","Environmental engineering; Waste treatment; Scheduling algorithms","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:92957dc5-3acf-4bff-a82d-18a4a8aed70d","http://resolver.tudelft.nl/uuid:92957dc5-3acf-4bff-a82d-18a4a8aed70d","Landslide susceptibility assessment for engineered slopes using statistical and deterministic approaches","Martinović, Karlo (Gavin and Doherty Geosolutions; University College Dublin); Gavin, Kenneth (TU Delft Geo-engineering; Gavin and Doherty Geosolutions); Reale, Cormac (University College Dublin)","","2016","Landslides cause hundreds of deaths and billions euros of damage to infrastructure and the environment each year. In order to predict the locations most susceptible to landslides, the field of landslide hazard assessment has gone through a massive development in the last twenty years by introducing a wealth of statistical and geotechnical landslide susceptibility models.
However, these efforts have been largely restricted to landslides occurring in natural terrain even though landslides occurring on geotechnical assets on transportation networks can result in even greater consequences. Current risk assessment approaches for earthworks on large transportation networks still largely take form of subjective risk matrices with inputs gathered by visual walkover surveys using data stored in an asset database.
This paper shows the application of two distinctive objective landslide susceptibility approaches on a case study of Irish rail. The first is a ‘statistical’, or ‘data-driven’ approach uses logistic regression as a statistical tool to establish the influence of slope-describing variables that have led to landslide occurrence. This approach draws the data from the asset database containing records of slope variables, and the adjoining landslide register. The same asset database is used as a basis for the second, ‘geotechnical’ or ‘deterministic’ approach. In this approach, geometrical and geotechnical properties of each slope are used to carry out probabilistic slope stability analysis, resulting in probability of failure for each slope.
Both approaches result in susceptibility zoning for earthwork assets across the network, effectively ranking them in the criticality terms. This study compares the requirements, applicability and outcomes of each approach, and discuss the methods needed for developing each of them into hazard and risk assessments.","Landslide susceptibility; Engineered slopes; Risk assessment; Transport network","en","conference paper","","","","","","","","","","","Geo-engineering","","",""
"uuid:23dcf3a7-2002-4078-bd2e-254758304dd7","http://resolver.tudelft.nl/uuid:23dcf3a7-2002-4078-bd2e-254758304dd7","Replacement of the initial steps of ethanol metabolism in Saccharomyces cerevisiae by ATP-independent acetylating acetaldehyde dehydrogenase","Kozak, B.U. (TU Delft BT/Industriele Microbiologie); Rossum, Harmen M. (TU Delft BT/Industriele Microbiologie); Niemeijer, M.S. (TU Delft BT/Industriele Microbiologie); van Dijk, M. (TU Delft BT/Industriele Microbiologie); Benjamin, Kirsten (Amyris Inc); Wu, Liang (DSM); Daran, J.G. (TU Delft BT/Industriele Microbiologie); Pronk, J.T. (TU Delft BT/Industriele Microbiologie); van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie)","","2016","In Saccharomyces cerevisiae ethanol dissimilation is initiated by its oxidation and activation to cytosolic acetyl-CoA. The associated consumption of ATP strongly limits yields of biomass and acetyl-CoA-derived products. Here, we explore the implementation of an ATP-independent pathway for acetyl-CoA synthesis from ethanol that, in theory, enables biomass yield on ethanol that is up to 40% higher. To this end, all native yeast acetaldehyde dehydrogenases (ALDs) were replaced by heterologous acetylating acetaldehyde dehydrogenase (A-ALD). Engineered Ald- strains expressing different A-ALDs did not immediately grow on ethanol, but serial transfer in ethanol-grown batch cultures yielded growth rates of up to 70% of the wild-type value. Mutations in ACS1 were identified in all independently evolved strains and deletion of ACS1 enabled slow growth of non-evolved Ald- A-ALD strains on ethanol. Acquired mutations in A-ALD genes improved affinity-Vmax/Km for acetaldehyde. One of five evolved strains showed a significant 5% increase of its biomass yield in ethanol-limited chemostat cultures. Increased production of acetaldehyde and other by-products was identified as possible cause for lower than theoretically predicted biomass yields. This study proves that the native yeast pathway for conversion of ethanol to acetyl-CoA can be replaced by an engineered pathway with the potential to improve biomass and product yields.","Acetyl-CoA; Energetics; Evolutionary engineering; Intracellular metabolites; Precursor supply; Yeast","en","journal article","","","","","","","","","","","BT/Industriele Microbiologie","","",""
"uuid:6e75d8f5-04d2-4ce9-92de-331562df6a54","http://resolver.tudelft.nl/uuid:6e75d8f5-04d2-4ce9-92de-331562df6a54","Conical shell edge disturbance: An engineer's derivation","Blaauwendraad, J. (TU Delft Applied Mechanics); Hoefakker, JH (TU Delft Applied Mechanics)","","2016","Because a rigorous bending theory for thin shells of revolution is complicated, attempts have been made for reliable approximations of the edge disturbance problem under axisymmetric loading. A well-known one was published by Geckeler [1, 2], who obtained his approximation by mathematical considerations. He started from kinematic, constitutive and equilibrium equations for the rotationally symmetric thin shell without approximations. Herein he introduced mathematical simplifications. Each time when derivatives of a function of different orders appeared, he just kept the highest order derivative and neglected all lower ones. This is permitted if the function varies rapidly, as is the case for edge disturbances. Here we will present Geckeler's result in an alternate way, which illustrates the physical background of his mathematical approximation. Said in another way, we offer a derivation in the language of structural engineers.","Edge disturbance zone; Engineer's approach; Rotationally symmetric shell","en","journal article","","","","","","","","","","","Applied Mechanics","","",""
"uuid:635375e0-bf26-4958-b110-53b539fc5e7c","http://resolver.tudelft.nl/uuid:635375e0-bf26-4958-b110-53b539fc5e7c","Ontology Engineering for the Design and Implementation of Personal Pervasive Lifestyle Support","van Bekkum, Michael A. (TNO); Krieger, Hans-Ulrich (German Research Centre for Artificial Intelligence (DFKI)); Neerincx, M.A. (TNO); Kaptein, F.C.A. (TU Delft Interactive Intelligence); Kiefer, Bernd (German Research Centre for Artificial Intelligence (DFKI)); Rijgersberg, R.M. (TU Delft Interactive Intelligence); Racioppa, Stefania (German Research Centre for Artificial Intelligence (DFKI))","Martin, Michael (editor); Cuquet, Marti (editor); Folmer, Erwin (editor)","2016","The PAL project1 is developing an embodied conversational agent (robot and its avatar), and applications for child-agent activities that help children from 8 to 14 years old to acquire the required knowledge, skills, and attitude for adequate diabetes selfmanagement. Formal and informal caregivers can use the PAL system to enhance their supportive role for this self-management learning process. We are developing a common ontology (i) to support normative behavior in a flexible way, (ii) to establish mutual understanding in the human-agent system, (iii) to integrate and utilize knowledge from the application and scientific domains, and (iv) to produce sensible human-agent dialogues. The common ontology is constructed by relating and integrating partly existing separate ontologies that are specific to certain contexts or domains. This paper presents the general vision, approach, and state of the art.","Common ontology; DIT++ standard; Embodied conversational agent; HFC inference engine; Human-agent dialogue; Ontology engineering","en","conference paper","","","","","","","","","","","Interactive Intelligence","","",""
"uuid:5daf2fe6-5750-4bb1-acb7-fca95415a129","http://resolver.tudelft.nl/uuid:5daf2fe6-5750-4bb1-acb7-fca95415a129","Pupil engineering to create sheets, lines, and multiple spots at the focal region","Konijnenberg, A.P.; Pereira, S.F.","","2015","In this paper we present several algorithms to find pupil functions which give focal fields with different desirable properties, such as a laterally elongated spot, a focal sheet, a spot with increased axial resolution, a lateral array of closely packed spots, and a lateral array of widely spaced diffraction-limited spots. All the algorithms work by writing the pupil function as a linear combination of appropriate basis functions, for which the coefficients are optimized. The focal field can be calculated repeatedly efficiently, since focal fields of each of the basis functions are precalculated. For each of the desired focal fields, the specific details of the algorithm are explained, simulation results are presented, and the results are compared to those in other publications.","focal field shaping; pupil engineering; SLM","en","journal article","IOP Publishing","","","","","","","","Applied Sciences","ImPhys/Imaging Physics","","","",""
"uuid:bd704806-913e-4319-8744-9cfc44f85fd5","http://resolver.tudelft.nl/uuid:bd704806-913e-4319-8744-9cfc44f85fd5","Socio-technical security metrics","Gollmann, D.; Herley, C.; Koenig, V.; Pieters, W.; Sasse, M.A.","","2015","Report from Dagstuhl seminar 14491. This report documents the program and the outcomes of Dagstuhl Seminar 14491 “Socio-Technical Security Metrics”. In the domain of safety, metrics inform many decisions, from the height of new dikes to the design of nuclear plants. We can state, for example, that the dikes should be high enough to guarantee that a particular area will flood at most once every 1000 years. Even when considering the limitations of such numbers, they are useful in guiding policy. Metrics for the security of information systems have not reached the same maturity level. This is partly due to the nature of security risk, in which an adaptive attacker rather than nature causes the threat events. Moreover, whereas the human factor may complicate safety and security procedures alike, in security this “weakest link” may be actively exploited by an attacker, such as in phishing or social engineering. In order to measure security at the level of socio-technical systems, one therefore needs to compare online hacking against such social manipulations, since the attacker may simply take the easiest path. In this seminar, we searched for suitable metrics that allow us to estimate information security risk in a socio-technical context, as well as the costs and effectiveness of countermeasures. Working groups addressed different topics, including security as a science, testing and evaluation, social dynamics, models and economics. The working groups focused on three main questions: what are we interested in, how to measure it, and what to do with the metrics.","Security risk management; security metrics; socio-technical security; social engineering; multi-step attacks; return on security investment","en","journal article","Schloss Dagstuhl - Leibniz-Zentrum für Informatik","","","","","","","","Technology, Policy and Management","Values Technology and Innovation","","","",""
"uuid:393d1946-65ac-4e11-be2b-886916f1eaeb","http://resolver.tudelft.nl/uuid:393d1946-65ac-4e11-be2b-886916f1eaeb","Growth-rate dependency of de novo resveratrol production in chemostat cultures of an engineered Saccharomyces cerevisiae strain","Vos, T.; De la Torre Cortes, P.; Van Gulik, W.M.; Pronk, J.T.; Daran-Lapujade, P.A.S.","","2015","Introduction: Saccharomyces cerevisiae has become a popular host for production of non-native compounds. The metabolic pathways involved generally require a net input of energy. To maximize the ATP yield on sugar in S. cerevisiae, industrial cultivation is typically performed in aerobic, sugar-limited fed-batch reactors which, due to constraints in oxygen transfer and cooling capacities, have to be operated at low specific growth rates. Because intracellular levels of key metabolites are growth-rate dependent, slow growth can significantly affect biomass-specific productivity. Using an engineered Saccharomyces cerevisiae strain expressing a heterologous pathway for resveratrol production as a model energy-requiring product, the impact of specific growth rate on yeast physiology and productivity was investigated in aerobic, glucose-limited chemostat cultures. Results: Stoichiometric analysis revealed that de novo resveratrol production from glucose requires 13 moles of ATP per mole of produced resveratrol. The biomass-specific production rate of resveratrol showed a strong positive correlation with the specific growth rate. At low growth rates a substantial fraction of the carbon source was invested in cellular maintenance-energy requirements (e.g. 27 % at 0.03 h?1). This distribution of resources was unaffected by resveratrol production. Formation of the by-products coumaric, phloretic and cinnamic acid had no detectable effect on maintenance energy requirement and yeast physiology in chemostat. Expression of the heterologous pathway led to marked differences in transcript levels in the resveratrol-producing strain, including increased expression levels of genes involved in pathways for precursor supply (e.g. ARO7 and ARO9 involved in phenylalanine biosynthesis). The observed strong differential expression of many glucose-responsive genes in the resveratrol producer as compared to a congenic reference strain could be explained from higher residual glucose concentrations and higher relative growth rates in cultures of the resveratrol producer. Conclusions: De novo resveratrol production by engineered S. cerevisiae is an energy demanding process. Resveratrol production by an engineered strain exhibited a strong correlation with specific growth rate. Since industrial production in fed-batch reactors typically involves low specific growth rates, this study emphasizes the need for uncoupling growth and product formation via energy-requiring pathways.","metabolic engineering; maintenance energy; anabolic products; qp; continuous culture; yeast; synthetic biology","en","journal article","BioMed Central","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:2512f403-521a-47af-8fba-bc433509e2ca","http://resolver.tudelft.nl/uuid:2512f403-521a-47af-8fba-bc433509e2ca","DynSem: A DSL for Dynamic Semantics Specification","Vergu, V.; Neron, P.; Visser, E.","","2015","The formal definition the semantics of a programming language and its implementation are typically separately defined, with the risk of divergence such that properties of the formal semantics are not properties of the implementation. In this paper, we present DynSem, a domain-specific language for the specification of the dynamic semantics of programming languages that aims at supporting both formal reasoning and efficient interpretation. DynSem supports the specification of the operational semantics of a language by means of statically typed conditional term reduction rules. DynSem supports concise specification of reduction rules by providing implicit build and match coercions based on reduction arrows and implicit term constructors. DynSem supports modular specification by adopting implicit propagation of semantic components from I-MSOS, which allows omitting propagation of components such as environments and stores from rules that do not affect those. DynSem supports the declaration of native operators for delegation of aspects of the semantics to an external definition or implementation. DynSem supports the definition of auxiliary meta-functions, which can be expressed using regular reduction rules and are subject to semantic component propagation. DynSem specifications are executable through automatic generation of a Java-based AST interpreter.","programming languages; dynamic semantics; reduction semantics; semantics engineering; IDE; interpreters; modularity","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:f4900d74-d24a-4533-9f41-3891558c4bfd","http://resolver.tudelft.nl/uuid:f4900d74-d24a-4533-9f41-3891558c4bfd","Using C Language Extensions for Developing Embedded Software: A Case Study","Voelter, M.; Van Deursen, A.; Kolb, B.; Eberle, S.","","2015","We report on an industrial case study on developing the embedded software for a smart meter using the C programming language and domain-specific extensions of C such as components, physical units, state machines, registers and interrupts. We find that the extensions help significantly with managing the complexity of the software. They improve testability mainly by supporting hardware-independent testing, as illustrated by low integration efforts. The extensions also do not incur significant overhead regarding memory consumption and performance. Our case study relies on mbeddr, an extensible version of C. mbeddr, in turn, builds on the MPS language workbench which supports modular extension of languages and IDEs","embedded software; language engineering; language extension; domain-specific language; case study","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:fe933714-a265-42b8-98d1-6809ac8ad105","http://resolver.tudelft.nl/uuid:fe933714-a265-42b8-98d1-6809ac8ad105","The 'Delft design method' for hydraulic engineers","Voorendt, M.Z.","","2015","This report intends to stimulate the discussion about enhancing and tuning the application of the traditional method for engineering design projects for educational purposes at Delft University of Technology - and possibly for the engineering practice as well. It aims at creating awareness of putting the design activities in a logical order and in applying the main design phases more consciously. It also attempts to enhance an integrated approach. The proposed improvements are not fundamental in the sense that they change themain design process, but they rather streamline the application of the method. I intend to incorporate feedback in a next version of this text, which will be available to anyone who is interested.","design method; hydraulic engineering","en","report","TU Delft, department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:3ff51afd-2c2e-4758-bc8b-ce256f2d252b","http://resolver.tudelft.nl/uuid:3ff51afd-2c2e-4758-bc8b-ce256f2d252b","Pupil engineering to create sheets, lines, and multiple spots at the focal region","Konijnenberg, A.P.; Pereira, S.F.","","2015","In this paper we present several algorithms to find pupil functions which give focal fields with different desirable properties, such as a laterally elongated spot, a focal sheet, a spot with increased axial resolution, a lateral array of closely packed spots, and a lateral array of widely spaced diffraction-limited spots. All the algorithms work by writing the pupil function as a linear combination of appropriate basis functions, for which the coefficients are optimized. The focal field can be calculated repeatedly efficiently, since focal fields of each of the basis functions are precalculated. For each of the desired focal fields, the specific details of the algorithm are explained, simulation results are presented, and the results are compared to those in other publications.","focal field shaping; pupil engineering; SLM","en","journal article","IOP Publishing","","","","","","","","Applied Sciences","ImPhys/Imaging Physics","","","",""
"uuid:d3fc86e3-5217-4bc7-a22a-9720937529c5","http://resolver.tudelft.nl/uuid:d3fc86e3-5217-4bc7-a22a-9720937529c5","Design of information-intensive systems involving cognitive aspects: An emerging opportunity for transdisciplinary cooperation","Vroom, R.W.; Van der Vegte, W.F.","","2015","With the rise of smart systems, ubiquitous computing and cyber-physical systems, information-intensiveness of products increases and users become challenged – possibly even overloaded – with expanding options and possible interactions. The number of possible variations of user-operation sequences can rapidly escalate and for designers it becomes difficult to foresee all possible outcomes, which might include unacceptable performance, failure, and even fatalities. With the objective to reduce the risk of unwanted cognitive effects and to realize a more symbiotic relationship between users and systems, we show how two model-based theories from cognitive science, i.e., cognitive architectures and mental models, can be deployed in the design of these systems. We argue that the deployment of such models requires a transdisciplinary approach in which designers intensively cooperate with cognitive scientists and end users.","cognitive engineering; information-intensive systems; mental models; cognitive architectures; transdisciplinary cooperation","en","book chapter","Springer International Publishing","","","","","","","2018-12-31","Industrial Design Engineering","Design Engineering","","","",""
"uuid:cae3d017-792c-49e6-afca-68b31a1ebf07","http://resolver.tudelft.nl/uuid:cae3d017-792c-49e6-afca-68b31a1ebf07","Engineering precursor supply in Saccharomyces cerevisiae: New strategies for cytosolic acetyl-CoA formation","Kozak, B.U.","Pronk, J.T. (promotor)","2015","Metabolic engineering – the improvement and addition, by genetic modification, of industrially relevant properties of microorganisms with respect to catalysis, transport and regulatory functions – is a well-established method for development of more cost-effective and ‘green’ industrial processes. Rapid depletion of oil reserves and a growing demand for sustainable, environmentally friendly processes provide incentives for efficient exploitation of new, renewable resources for the production of transport fuels and bulk chemicals. The narrow profit margins that are typical for such commodity products, impose a need to optimize processes in terms of kinetics of product formation and, especially, yield of product on feedstock. Metabolic engineering of microorganisms, with its continuously expanding toolbox, allows researchers to address the challenges involved in the development of biotechnological processes that can compete with petrochemical production. Due to its robustness in industrial fermentation processes and fast developments in yeast synthetic biology, Saccharomyces cerevisiae (a.k.a. baker’s yeast) has become one of the most popular metabolic engineering platforms in modern biotechnology. As a result, this microorganism, after having been used for ages in the production of alcoholic beverages and bread, is now recognized as multi-purpose microbial ‘workhorse’ with numerous industrial applications. Production of many natural and heterologous compounds with genetically modified strains of S. cerevisiae is under investigation or has already been implemented in industry. Many of those biochemicals, for example n-butanol, isoprenoids, lipids, flavonoids and 3-hydroxypropionic acid, require acetyl coenzyme A (acetyl-CoA) as a key precursor. The metabolism of this compound in S. cerevisiae cells is compartmentalised. The mitochondrial route, responsible for a substantial flux towards acetyl-CoA during respiratory growth on sugars, involves conversion of mitochondrial pyruvate into acetyl-CoA in the reaction catalysed by the pyruvate dehydrogenase complex. Since, in S. cerevisiae, acetyl-CoA cannot be exported from the mitochondria, another pathway is required to cover biosynthetic requirements for acetyl-CoA in the cytosolic compartment. This so-called ‘pyruvate dehydrogenase bypass’ requires the concerted activity of pyruvate decarboxylase, acetaldehyde dehydrogenase and acetyl-CoA synthetase. The latter two reactions are also required for growth on the C2-compounds – acetate (only acetyl-CoA synthetase) and ethanol. When ethanol is used as a carbon source, it is first converted to acetaldehyde in the reaction catalysed by alcohol dehydrogenases and further to acetyl-CoA, which is used to cover all biosynthetic and energetic requirements of ethanol-grown cells. Heterologous, acetyl-CoA-dependent product pathways expressed in the cytosol of S. cerevisiae exclusively depend on the cytosolic route for provision of this precursor. As a result, several previous metabolic engineering studies have been devoted to improving the synthesis of the cytosolic acetyl-CoA. Although successful in increasing the availability of this compound, by improving the capacity of the native route or by introduction of the heterologous pathways of cytosolic acetyl-CoA synthesis, those studies primarily focused on the kinetic parameters, while the energetic aspects of cytosolic acetyl-CoA synthesis received little attention. The maximum yield of biomass or of any other industrially relevant product on a substrate depends on the energy (ATP) cost of the biochemical pathways used for precursor and product formation. The synthesis of cytosolic acetyl-CoA in S. cerevisiae involves hydrolysis of ATP to AMP and pyrophosphate (PP i ) in the reaction catalysed by acetyl-CoA synthetase (ACS). The subsequent hydrolysis of PP i to inorganic phosphate (P i ) makes the energetic cost of cytosolic acetyl-CoA synthesis equivalent to hydrolysis of 2 ATP to 2 ADP and 2 P i . This ATP expenditure has a profound impact on the maximum yields of acetyl-CoA-dependent products that can be achieved in engineered yeast strains and, therefore, negatively influences the economy of the production process. Especially in the case of bulk chemicals and bio-fuels, this single ATP-consuming reaction can become cost-prohibitive. This thesis explores metabolic engineering strategies to address this key challenge in yeast biotechnology. After general introduction to metabolic engineering and S. cerevisiae, Chapter 1 describes the strategies that have hitherto been explored to increase the availability of cytosolic acetyl-CoA. Moreover, this Chapter discusses other pathways of cytosolic acetyl-CoA synthesis that occur in nature, some of which do not require an input of ATP and could therefore, upon expression in S. cerevisiae, lead to increase of maximum yields of acetyl-CoA-dependent products on substrate in engineered yeast strains. In S. cerevisiae, cytosolic acetyl-CoA synthesis and growth strictly depend on functional expression of either the Acs1 or Acs2 isoenzyme of acetyl-CoA synthetase (ACS). Before the research described in this thesis, viable S. cerevisiae strains in which both ACS1 and ACS2 had been deleted, had not been described in the literature. In addition to its anabolic and, under certain conditions, catabolic roles, cytosolic acetyl-CoA also plays key role in cellular regulation via acetylation of proteins, including histones. Chapter 2 explores the feasibility of replacing the native S. cerevisiae pathway for cytosolic acetyl-CoA synthesis by two alternative, ATP-independent pathways, and investigates their impact on growth and energetics of the engineered yeast strains. To this end, the native route of cytosolic acetyl-CoA synthesis was replaced by either an acetylating acetaldehyde dehydrogenase (A-ALD) or a pyruvate-formate lyase (PFL). Acetylating acetaldehyde dehydrogenase catalyses direct, ATP-independent oxidation of acetaldehyde to acetyl-CoA, while pyruvate-formate lyase converts cytosolic pyruvate into equimolar amounts of acetyl-CoA and formate. After evaluating the expression of different genes encoding acetylating acetaldehyde dehydrogenase and pyruvate-formate lyase, acs1? acs2? S. cerevisiae strains were constructed in which A-ALD or PFL functionally replaced ACS. In case of the A-ALD-dependent strains, also all acetaldehyde dehydrogenases were deleted, which resulted in complete replacement of the two-step conversion of acetaldehyde to acetyl-CoA, by a one-step reaction catalysed by A-ALD. The A-ALD-dependent strains showed aerobic growth rates of up to 79% of the reference strain, while anaerobic growth rates of PFL-dependent S. cerevisiae reached up to 73% of the growth rate of the reference strain. Physiological characterisation of the fastest growing A-ALD- and PFL-dependent strains was performed in glucose-limited chemostat cultures. Unexpectedly, the measured biomass yields on glucose of A-ALD- and PFL-dependent strains were 14% and 15% lower than those of the reference strain, respectively. Weak-acid uncoupling by formate, the formation of which was stoichiometrically coupled to growth of PFL-dependent strain, offers a plausible explanation for the reduced biomass yield of this strain. In A-ALD-dependent strain, the reduced biomass yield of the A-ALD-dependent strain was attributed to toxic effects of the acetaldehyde, which was present at higher levels in cultures of the engineered strain than in cultures of the reference strain. Changes in the synthesis of cytosolic acetyl-CoA might affect histone acetylation as well as central metabolism via acetylation of non-histone proteins and direct participation of this compound in key reactions. However, transcriptome analysis of A-ALD- and PFL-dependent strains revealed only small sets of genes with altered expression levels relative to the reference strain. Combined with their high growth rates, these observations suggested that these strains did not suffer from major limitations in acetyl-CoA provision. This conclusion was further supported by the minor differences in intracellular metabolite levels of an A-ALD-dependent strain relative to the control strain. Intracellular acetyl-CoA concentrations, which reflect the combination of mitochondrial and nucleocytosolic pools, were also not significantly different between A-ALD-dependent strain and the reference strain, which may suggest that intracellular concentrations of acetyl-CoA are subject to strong homeostatic regulations. Higher intracellular lysine concentrations in A-ALD-dependent strain might even be indicative for increased availability of cytosolic acetyl-CoA. The research presented in Chapter 2 demonstrated, for the first time, that the native pathway for cytosolic acetyl-CoA synthesis in S. cerevisiae can be entirely replaced by heterologous, ATP-independent pathways. During respiratory growth of S. cerevisiae on glucose, cytosolic acetyl-CoA is required to cover biosynthetic requirements of the cell, including the biosynthesis of lysine and of lipids. However, these biosynthetic fluxes are relatively small compared to the overall rate of ATP turnover and, therefore, have a relatively small impact on growth energetics (calculated impact on biomass yield in aerobic, glucose-limited cultures < 0.5%). A fundamentally different situation arises when ethanol is used as a carbon source and acetyl-CoA synthetase is the starting point for all biosynthetic and dissimilatory pathways in growing yeast cells. Under these conditions, saving of the 2 ATP required for synthesis of each molecule of cytosolic acetyl-CoA, should theoretically enable an increase of the biomass yield from 0.57 g/g ethanol for the native route up to 0.80 g/g ethanol for an ATP-independent pathway. Such a dramatic increase in the energetic efficiency of ethanol utilization could be highly relevant for industry, as it should result in higher yield on ethanol of any acetyl-CoA-dependent product. Therefore, Chapter 3 focuses on yeast strains in which the native pathway for acetyl-CoA synthesis was replaced by A-ALD. The A-ALD-dependent strains, however, did not show immediate growth on media with ethanol as the sole carbon source. Prolonged incubation, followed by long-term laboratory evolution experiments, yielded A-ALD-dependent yeast strains that were able to grow on ethanol with specific growth rates up to 0.11 h ?1 . Reverse engineering studies showed that mutations in ACS1, the gene that encodes one of the S. cerevisiae cytosolic acetyl-CoA synthetases, were essential for growth on ethanol of the A-ALD-dependent strains. Acquired mutations in A-ALD genes improved V MAX /K M for acetaldehyde of the encoded enzymes, but were not essential for growth on ethanol. Although the reverse engineered strains grew on ethanol, their growth rates were lower than the growth rates of the evolved strains. Further analysis of the growth of these strains suggested a limited availability of mitochondrial acetyl-CoA during growth of the A-ALD-dependent strains on ethanol. Out of five evolved strains tested in ethanol-limited chemostat cultures, only one evolved strain showed a 5% increase in the biomass yield on ethanol compared to the reference strain, which was far below the 40% theoretical prediction. Increased production of acetaldehyde and other byproducts was identified as possible cause for these suboptimal biomass yields. This study in Chapter 3 proves that the native yeast pathway for conversion of ethanol to acetyl-CoA can be replaced by an engineered pathway that has the potential to strongly improve biomass and product yields. Based on metabolic and evolutionary engineering, whole-genome resequencing, reverse engineering and physiological analysis of evolved strains, we identify intracellular acetaldehyde levels and provision of intramitochondrial acetyl-CoA as key targets for further optimization of ethanol conversion by eukaryotic cell factories. Pyruvate dehydrogenase (PDH) is a huge, multisubunit enzyme complex whose size is comparable to that of a ribosome. The PDH complex catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA which, in many organisms, is the key reaction at the interface of glycolysis and tricarboxylic acid cycle (TCA). In eukaryotes, the PDH complex occurs exclusively in the mitochondrial matrix and, therefore, cannot contribute to provision of cytosolic acetyl-CoA in S. cerevisiae. In Chapter 4, the challenge of the expression of a functional, heterologous PDH complex in the yeast cytosol is taken up. In order to determine if a heterologous PDH complex can replace the native route of cytosolic acetyl-CoA formation in S. cerevisiae, the PDH complex from the bacterium Enteroccocus faecalis was selected to be expressed in yeast. Three factors contributed to selecting the PDH complex from E. faecalis for this study: (i) bacterial PDH subunits presumably lack mitochondrial localization sequences; (ii) E. faecalis PDH is relatively insensitive to high NADH/NAD + ratios in comparison to other bacterial PDH’s; and (iii) in vitro experiments indicate that purified subunits of the E. faecalis PDH can self-assemble into a functional complex. All known PDH complexes require four cofactors for their activity: FAD + , NAD + , thiamine pyrophosphate (TPP) and lipoic acid. In S. cerevisiae, lipoic acid is synthesized and covalently attached to the PDH complex in the mitochondria. Therefore, cytosolic expression of a bacterial PDH complex was likely to require co-expression of proteins that catalyze lipoylation of PDH, as well as addition of lipoate to the media. The expression of genes encoding the four subunits of the E. faecalis PDH complex, together with two lipoate ligases from E. faecalis in the cytosol of S. cerevisiae, combined with deletion of ACS1 and ACS2, enabled growth of an acs1? acs2? strain of S. cerevisiae on glucose. The strict dependency of growth on the addition of lipoic acid confirmed the in vivo activity of the heterologous PDH complex. The aerobic growth rate on glucose of the obtained strain (0.36 h ?1 ) was comparable to the growth rate of the reference strain (0.42 h ?1 ) and independent of the concentration of lipoic acid in the range of 20 ng mL ?1 to 1000 ng mL ?1 . The Acs ? yeast strain expressing the bacterial PDH complex also showed a near-wild-type growth rate under anaerobic conditions (0.30 h ?1 and 0.33 h ?1 for engineered and wild-type strain, respectively). Functioning of the E. faecalis PDH complex in anaerobic yeast cultures indicates that it can also be applied in the design and construction of anaerobic product pathways. Enzyme activity assays indicated that, in an engineered strain, PDH from E. faecalis yielded higher specific activity (53 nmol min ?1 mg protein ?1 ) than the activity of the mitochondrial PDH of S. cerevisiae (12 nmol min ?1 mg protein ?1 ). The cytosolic localization of the heterologously expressed E. faecalis PDH complex in the yeast cytosol was confirmed by subcellular fractionation, combined with enzyme activity assay and mass-spectrometry-based proteomics. While the specific activities of the PDH in the mitochondrial fractions of engineered strain and the wild-type strain were not significantly different, the specific activity of PDH measured in the cytosolic fraction of Acs ? strain expressing PDH of E. faecalis was 32-fold higher than that of the wild-type strain. The cytosolic localization of the four subunits of the E. faecalis PDH complex, as well as of the two lipoate ligases of E. faecalis in the cytosol of S. cerevisiae was further confirmed by mass spectrometry-based proteome analysis of the cytosolic fraction. In E. faecalis, PDH occurs as a protein complex consisting of 210 subunits. Gel filtration of a cytosolic fraction, combined with enzyme activity measurements and proteomics analysis, demonstrated that E. faecalis PDH was present in the cytosol of S. cerevisiae as a complex with a size, a specific activity, and a relative abundance of the E1, E2, and E3 subunits comparable to those reported for native E. faecalis PDH. Chemostat-based physiological characterization in glucose-limited chemostat cultures showed comparable biomass yields and rates of sugar dissimilation for the Acs ? strain expressing PDH and a reference strain. These results, together with the absence of strong differences in the transcriptome of engineered and native strains, indicated that replacement of the cytosolic acetyl-CoA synthesis with PDH complex from E. faecalis did not lead to significant disturbances of the physiology of S. cerevisiae. The research described in this thesis demonstrates that complete replacement of the native route of cytosolic acetyl-CoA formation in S. cerevisiae with heterologous ATP-independent pathways can result in viable yeast strains. Moreover, it delivers proof of concept that implementation of the ATP-independent pathways may result in increased biomass yield on substrate. These strategies appear to be particularly suited for improving the product yield on sugar of any compound, produced in S. cerevisiae, that uses cytosolic acetyl-CoA as a precursor. Therefore, the results presented in this thesis provide metabolic engineers with new strategies to optimize the performance of Saccharomyces cerevisiae as a ‘cell factory’ for sustainable production of fuels and chemicals.","Saccharomyces cerevisiae; acetyl-CoA; metabolic engineering","en","doctoral thesis","","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:02c9ef29-4afa-4cd6-8240-25d4aaa9b06f","http://resolver.tudelft.nl/uuid:02c9ef29-4afa-4cd6-8240-25d4aaa9b06f","Preliminary Assessment of Debris Flow Hazard in a Catchment under Extreme Condition","Gao, L.; Zhang, L.M.; Chen, H.X.","","2015","Due to hilly terrain and frequent heavy rainstorms, debris flow is one of the most common and catastrophic hazards in Hong Kong. To mitigate the debris flow risk, prediction of the magnitude and consequence of debris flow is essential. The objective of this paper is to simulate debris flow hazards in a study area in Hong Kong. Assessment of the surface geology is firstly conducted to ascertain the source materials. The physical parameters of the loose materials such as size, location, and soil type are investigated. The volume, sediment concentration and resistance parameters for debris flows are subsequently evaluated and adopted as the input for the debris flow simulation. Numerical debris flow simulation is then conducted according to the established parameters. The maximum flow depth and maximum flow velocity are calculated by solving the continuity equation, the momentum equation and a friction slope equation. Based on the simulation results, a debris flow hazard map as a function of both the maximum flow depth and the maximum flow velocity is finally produced.","Debris flow; hazard assessment; engineering geology; deposition","en","conference paper","","","","","","","","","","","","","",""
"uuid:64a32897-a5d3-4e23-bc75-2b88c0768fc3","http://resolver.tudelft.nl/uuid:64a32897-a5d3-4e23-bc75-2b88c0768fc3","Limit State Imprecise Interval Analysis in Geotechnical Engineering","Marques, S.H.; Beer, M.; Gomes, A.T.; Henriques, A.A.","","2015","The first applications of nonprobabilistic interval analysis in geotechnical engineering have been recently explored. In fact, the solution of practical problems in this field often requires judgement based on limited data and interval analysis has become a research area formally motivated by input information characterised by imprecision. Whenever no information apart from bounds is available, intervals may be considered in the form of a model noted that they are among the most widely used analytical tools to describe uncertainty by using nonprobabilistic approaches. However, the application of a pure interval analysis to engineering problems may lead to large overestimation due to the dependency phenomenon and meaningful results are only obtained when a decision is based on threshold values. A mixed approach that admits imprecise information as well as probabilistic information is therefore desirable. In this paper the conventional probabilistic approach to uncertainty is extended to include imprecise information in the form of intervals. For demonstration, results are provided for a strip spread foundation designed by the Eurocode 7 methodology, wherein the shear strength parameters of the foundation soil are implemented as intervals and then combined with other uncertain parameters in the form of bounded random variables under dependence. A limit state imprecise interval analysis for safety assessment is then presented in the format of a sensitivity analysis.","geotechnical engineering; uncertainty; imprecise interval analysis","en","conference paper","","","","","","","","","","","","","",""
"uuid:a8b3b02b-5ebe-4782-93be-c640a07c3816","http://resolver.tudelft.nl/uuid:a8b3b02b-5ebe-4782-93be-c640a07c3816","Limit State Imprecise Probabilistic Analysis in Geotechnical Engineering","Marques, S.H.; Beer, M.; Gomes, A.T.; Henriques, A.A.","","2015","The treatment of imprecision attracted continuous interest since the origin of probability as the science of uncertainty. As a matter of fact, probability has been developed to deal with uncertainty and the first argument supporting precise rather than imprecise probability counts on the nature of ordinary measurements. Starting from only a few papers wherein imprecise probability has been explored as a marginal alternative to precise probability, a number of devoted works appeared with intensified frequency in the second half of the 20th century. From first developments, imprecise probability emerged in the field of engineering by different approaches. The key feature consists in the identification of probability bounds for scenarios of interest with extended application in model validation, provided the ingredients for a systematic investigation of sensitivities. In this way, regardless of the increased interest in probabilistic methods within the geotechnical engineering community, unresolved issues may comprehend a discrepancy in reliability studies regarding the frequency of failure whereas enough tests are very seldom available for a definite choice of the best statistical model. A mixed approach that admits imprecise information as well as probabilistic information is therefore desirable. In this paper the conventional probabilistic approach to uncertainty is extended to include imprecise information in the form of intervals. For demonstration, results are provided for a strip spread foundation designed by the Eurocode 7 methodology, wherein the shear strength parameters of the foundation soil are implemented as intervals and then combined with other uncertain parameters in the form of random variables under dependence.","geotechnical engineering; uncertainty; imprecise probabilistic analysis","en","conference paper","","","","","","","","","","","","","",""
"uuid:0a18a5e5-7109-4fab-97fb-b2a99d9f3726","http://resolver.tudelft.nl/uuid:0a18a5e5-7109-4fab-97fb-b2a99d9f3726","An Integrated Knowledge Based Engineering Mechatronics Modeling Approach to Support the Design of Unstable and Unmanned Aircraft","Tian, F.N.","Veldhuis, L.L.M. (promotor)","2015","The commercial transport aircraft industry is currently developing new “more electric aircraft” (MEA) designs in which various conventional mechanical, hydraulic and pneumatic power systems are replaced with electrically-based power systems. Their objective is to improve the overall flight performance by reducing the aircraft weight and by a lower overall energy requirement for the systems. The vision for the future is to ultimately replace all systems with electrical systems and even to replace a part of the fuel used as primary source of energy for the propulsion system by an electrical power supply and thereby to achieve either a hybrid electric aircraft (HEA) or even all electric aircraft (AEA) if permitted by future developments in battery technology. In recent years, many small scale electric aircraft were developed to demonstrate the AEA concept. It has been determined that although the MEA, HEA and AEA concepts reduce the overall complexity of the aircraft, it significantly increases the complexity of electrical and electronic systems (E/E systems) and their integration into the aircraft, introducing a new challenge for the aircraft design industry. Two specific categories of aircraft, currently in operation, face the same challenge. These categories are; (1) unmanned aerial vehicles (UAVs), which by nature have more electrical and electronic systems (E/E systems) on-board and require an automatic flight control system due to the absence of a pilot and (2) aircraft which are inherently unstable and therefore require automatic flight control systems for stabilization. These two aircraft categories can be classified as typical mechatronic products. E/E systems have a significant impact on the overall flight performance, directly determine the flying qualities of aircraft, and are critical for safety. Thus, these systems should be developed synchronously with the other traditional engineering domains such as aerodynamics, structures and propulsion. However, several challenges need to be overcome before this can be achieved effectively. Three specific challenges are identified and addressed in the current research study: The development of high fidelity multiphysics simulation models for analysis and development of the E/E systems is a complex, time consuming and multidisciplinary task that requires a large amount of manual work from simulation experts; The design of consistent automatic flight control systems for use throughout the entire flight envelope and for all aircraft weight and c.g. combinations is labor intensive and requires the availability of high fidelity multiphysics simulation models in the early design phases; The development of control software components is prone to errors due to inconsistencies between the description of the top level physical configuration, the control architecture and the associated software components. Traditional aircraft design methods which are largely dominated by the mechanical engineering domains are not suitable to synchronously design complex integrated E/E systems. Moreover, the conventional design process, which is sequential to a large extent, cannot support concurrent engineering requirements. Therefore, novel methods and tools to support the development of the E/E systems on-board aircraft are needed. The overall objective of this research study is to reduce the development time of aircraft with a high level of integrated E/E systems by automating the design process of the flight control systems, by creating more consistent control software through the entire design envelope. Besides a reduction in development time this will also improve the quality of the final (mechatronic) product. The three challenges described above will be tackled in particular. The novel methods and tools are based on the knowledge based engineering (KBE) approach. The KBE approach is highly suitable because it cannot only automate non-creative, repetitive design tasks done for example by simulation experts but also support for multidisciplinary design, analysis and optimization (MDAO). Compared to other existing KBE systems, the proposed system integrates the flight control system design with the physical design in three specific areas. First, in order to ensure a consistent design representation, the concept of a multiphysics information model (MIM) is proposed in order to integrate the design knowledge present from multiple engineering domains. The proposed MIM (a KBE system) defines objects with attributes to represent various aspects of physical entities (e.g., mass, inertia, geometry, material properties). Moreover, it uses functions to capture non-physical information, such as the control architecture, relevant test maneuvers, simulation procedures, etc. The problem of system coupling and interactions between disciplines involved are taken into account by the proposed KBE system in a knowledge acquisition process. Next, depending on the requirements, the proposed KBE system extracts necessary knowledge from the MIM which is needed for the development of a multiphysics simulation model, which is composed of a physical plant, flight control systems including the embedded control software and simulation configurations. By capturing the expertise of simulation experts, the proposed KBE system is able to automatically instantiate the multiphysics simulation models. This multiphysics simulation model can be used to evaluate the flight control systems in operation practice throughout the flight envelope, for example when performing maneuvers. Altogether, the MIM enables rapid development of high fidelity multiphysics simulation models for analysis and development of the flight control systems. Second, in order to evaluate the inherent flying qualities of unstable aircraft in a simulation environment, an automatic flight control system is required. For this purpose, model based inversion control is applied. This method has the advantage that tuning is not required. The techniques, processes and knowledge required to develop a model based control system based on the (nonlinear) multiphysics simulation model are captured by the KBE system. Model based inversion control has its disadvantages when implemented on real-life aircraft. For the final design solution developed by the framework, which will enter the detailed design phase and which will ultimately be produced, other control methods and architectures can be developed, more appropriate for a real-life situation. Such a control system will only have to be tuned and developed once in contrast to the thousands of designs evaluated in an MDO framework. This application of model based inversion control is considered new. Third, in order to avoid errors in the embedded control software as a result of manual programming activities, the dependencies of parameters in the software on physical parameters of an evolving design and the high complexity (thousands of lines of code), control software components of flight control systems should ideally be developed in an automated fashion. The proposed KBE system has the ability to generate consistent control software components. The system extracts the variable definitions and values from physical configurations and control architecture from the information model to specify the variables in the software components. In addition, the system divides software components into basic elements and writes them into strings, which can, in principle, be any computer language. When the top level configuration and control architecture changes, the proposed KBE system can operate the basic elements in specific order and automatically create new software components by capturing the expertise from software engineers. Summarizing, because both the geometry model and multiphysics simulation model including flight control system are obtained from one source, the MIM links the physical modeling and control system design with the development of software components with respect to data and topology structure. A multirotor UAV configuration is used as test case to demonstrate the novel methods and tools described above. This is an inherently unstable configuration with a wide range of applications. A computational framework is developed which enables the conceptual/preliminary design and optimization of this typical mechatronic product. The proposed KBE system automatically creates thirty thousand designs of multirotor UAVs with different topologies and then evaluates each solution by automatically simulating five test maneuvers and by checking twenty-two constraints. Results show that the proposed KBE system can automatically generate multiphysics simulation models to support the multidisciplinary analyses not restricted to the mechanical domain but also applicable for evaluation of flight control systems and other domains. Even though different design solutions can have a highly different topology, automatic flight control systems based on the model inversion control method are created automatically for each design solution, enabling the evaluation of the inherent flying qualities of the unstable aircraft configuration. Furthermore, within the framework, design processes are automatically completed from the initial definition of top-level aircraft requirements, to the design and optimization, and finally down to selecting feasible solutions. The approach demonstrated leads to: a reduction in manual work, improved quality of the final solution, and consistent control system and software components. Key to the MIM concept is that it focuses on capturing the intrinsic properties of physical systems by the KBE approach and a specific format of representation is avoided. Although the current research study focuses on the software of the flight control systems in particular, the concept of the MIM can in principle be applied to design the complete E/E system, including hardware components, as well as other multiphysics systems.","multiphysics simulation model; electronic control system; knowledge based engineering; unmanned aerial vehicle; multidisciplinary design optimization","en","doctoral thesis","","","","","","","","2015-09-24","Aerospace Engineering","Aerospace Engineering","","","",""
"uuid:cc231be1-662c-4b1f-a1ca-8be22c0c4177","http://resolver.tudelft.nl/uuid:cc231be1-662c-4b1f-a1ca-8be22c0c4177","Double-curved precast concrete elements: Research into technical viability of the flexible mould method","Schipper, H.R.","Vambersky, J.N.J.A. (promotor); Van Breugel, K. (promotor)","2015","The production of precast, concrete elements with complex, double-curved geometry is expensive due to the high costcosts of the necessary moulds and the limited possibilities for mould reuse. Currently, CNC-milled foam moulds are the solution applied mostly in projects, offering good aesthetic performance, but also resulting in waste of material, relatively low production speed and fairly high costs per element. The flexible mould method aims to offer an economic alternative for this state of art technology by allowing repeated reuse of the same mould, and if necessary, reuse in adapted shape. A patent and literature review and comparison of state-of-art formwork methods reveals that, although the idea of a flexible formwork already dates from the mid-20th century, in building industry it has not yet found widespread application, and is still experimental to a large extent. In other industries, such as aerospace and automotive, flexible moulds are occasionally used for rapid prototyping purposes, mostly for the forming of thin metal sheets. The understanding of the flexible mould principle in terms of mechanics is still in development. In combination with concrete, the flexible mould has been industrially applied only on occasion. Deliberately imposed deformation of concrete after casting allows the use of only one single-sided flexible mould, but - being a method quite alien to normal precast concrete production - has hardly been investigated. Therefore, models are needed both for the flexible layer as well as it's use in combination with concrete. By analysing a number of architectural cases in terms of geometrical aspects, more information is gathered about building size, element thickness, curvature radius and number and type of elements. This information is used to define the type of shapes for which the flexible mould method would be suitable. Through the last 80 years, the shape of curved architecture has changed; whereas the early famous shell designers such as Isler and Torroja aimed for structurally optimized and material-efficient shapes, nowadays these shapes have mostly made place for free-form curves, in which parametric design or sculptural influences are leading. For larger projects, several hundreds to even thousands of uniquely curved elements are manufactured, varying in curvature radius in a range between 0.75 m and 45 m. Furthermore the contours and edge position can vary from element to element. Prediction of each element's edge position is non-trivial for the flexible mould method, especially not for elements with strong curvature. The deformation process can be described mathematically by analysing thecurvature parameters. An important and meaningful parameter is the Gaussian curvature. Depending on the change in Gaussian curvature, the imposed deformation of the mould surface and the concrete results in certain amounts of bending action (B) and in-plane surface stretching (S). Bending tensile strains in the still plastic concrete can be in the range of 25 to 50 for an element with 50 mm thickness, which is far more than the values normally encountered in concrete after casting. The application of in-plane shear deformation appears to be helpful to deform the mould from flat to double-curved. The exact positioning of the element edges can be determined from this in-plane shear deformation. The shape of the mould, in the present research, is controlled by a grid of actuators - extendible support points that follow the intended architectural shape. As mould surface, a thin rubber layer can be used, that, however, has to be supported by a material that is capable of carrying the weight of the concrete without visible deflection between the actuators. Various solutions are investigated for this support material, of which the strip mould offers the most accurate results and predictability. As said, the concrete in this method is deliberately deformed after casting in an open, single-sided mould. This requires control over both the fluidity and strain capacity of the fresh concrete: if the concrete is too fluid, it will flow out of the mould after deformation due to the slope of the mould, if it is already too stiff, cracks may occur. Various experiments are conducted to investigate the viability of the principle as well as the parameters that influence the risk of either flow or cracking. It appears that the use of a self-compacting concrete with thixotropic properties reduces both the risks: as a result of quick stabilisation after casting, the yield strength build-up will prevent flow once the mould is deformed and put at a certain slope. Thanks to it's plastic strain capacity, this type of concrete will be able to undergo the imposed deformation without cracking. An important measure to prevent this cracking is the curing of the concrete directly after casting and a deformation that takes place before initial setting time. Thin steel rebar, glass-fibre textiles or mixed fibres are all applicable as reinforcement, the latter two giving the best results. For the measurement of yield strength development of the concrete mixture before and after casting, various methods are investigated. Literature research and experiments demonstrate that, once the rheological behaviour of a mixture has been determined with a viscometer accompanied with slump (flow) tests, the correct moment of deformation of the flexible mould can later be determined from repeated slump (flow) tests with sufficient reliability. However, as soon as the mixture constituents will be adapted, new viscometer measurements have to be carried out again. The flexible mould method has been successfully tested on single- and double-curved precast concrete elements with a radius down to 1.50 m and an element thickness up to 50 mm. Until this moment, the maximum element size tested was approximately 2 x 1 m2, but larger elements are expected to be feasible. An integrated design-to-production process is required: due to the complex geometry and the impact of this geometry on all aspects of the manufacturing, all parties involved should cooperate to make the use of this method possible. Computational skills are needed to determine design parameters and control the manufacturing process. Several new questions were identified during the research, but at this moment, implementation of the flexible mould method in an industrial environment in cooperation with a concrete product manufacturer is the best way to determine the priorities for further research. From the full research it is concluded that the flexible mould method is viable for the production of double-curved concrete elements.","concrete; precast; double-curved; doubly curved; curved; panels; cladding; elements; rheology; thixotropy; complex geometry; architecture; structural engineering; building; fabrication; CNC; mould; mold; file-to-factory; production; gaussian curvature; panelisation; panelization; beton; dubbelgekromd; prefab; geprefabriceerd; architectuur","en","doctoral thesis","","","","","","","","2015-08-14","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:f023941f-a79f-493c-9131-46934ce1746b","http://resolver.tudelft.nl/uuid:f023941f-a79f-493c-9131-46934ce1746b","Reflections on the role of energy network companies in the energy transition","Steenhuisen, B.M.; De Bruijne, M.L.C.","","2015","Background Energy network companies are commonly attributed the public task to help society in becoming greener in the domain of energy. This extra public task has high costs and comes with high uncertainties. It may also compete with existing public tasks of network companies. When network companies are involved in local green initiatives, they encounter dilemmas and need to arrange trade-offs among multiple public values. It may also compete with existing tasks of network companies. Therefore, these network companies can face dilemmas when involved in local green initiatives. The aim of this paper is to reflect on the role of energy network companies in the face of these dilemmas. What is the role of energy network companies in coping with conflicting public values when helping local initiatives that create a greener energy system? Methods We answer this question via an essay that reflects on existing research in the Dutch energy sector. Our answer is derived from the fields of law, politics, policy, economics and engineering about the role of network companies. Results and discussion We argue that these five perspectives leave the role of energy network companies in the energy transition under-articulated. Our additional answer is based on our own empirical research that focuses on how network companies currently deal with dilemmas between multiple public tasks. Conclusion We provide an analytical framework that enables a way of understanding the role of network companies in the struggle with dilemmas and raise several points of discussion to that might refocus efforts of researchers and practitioners to elucidate the role of network companies.","energy network companies; energy transition; law; politics; policy; economics; engineering; OA-Fund TU Delft","en","journal article","BioMed Central","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:cef646ea-ee6e-475a-a2a8-4c6b1f46f62a","http://resolver.tudelft.nl/uuid:cef646ea-ee6e-475a-a2a8-4c6b1f46f62a","Adaptive User Feedback for IR-Based Traceability Recovery","Panichella, A. (TU Delft Software Engineering); De Lucia, Andrea (University of Salerno); Zaidman, A.E. (TU Delft Software Engineering)","","2015","Trace ability recovery allows software engineers to understand the interconnections among software artefacts and, thus, it provides an important support to software maintenance activities. In the last decade, Information Retrieval (IR) has been widely adopted as core technology of semi-automatic tools to extract trace ability links between artefacts according to their textual information. However, a widely known problem of IR-based methods is that some artefacts may share more words with non-related artefacts than with related ones. To overcome this problem, enhancing strategies have been proposed in literature. One of these strategies is relevance feedback, which allows to modify the textual similarity according to information about links classified by the users. Even though this technique is widely used for natural language documents, previous work has demonstrated that relevance feedback is not always useful for software artefacts. In this paper, we propose an adaptive version of relevance feedback that, unlike the standard version, considers the characteristics of both (i) the software artefacts and (ii) the previously classified links for deciding whether and how to apply the feedback. An empirical evaluation conducted on three systems suggests that the adaptive relevance feedback outperforms both a pure IR-based method and the standard feedback.","Empirical Software Engineering; Information Retrieval; Software Traceability; User Feedback Analysis","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","","","","","","Software Engineering","","",""
"uuid:94f68c74-67c5-454e-87b6-a1f42cddf3d0","http://resolver.tudelft.nl/uuid:94f68c74-67c5-454e-87b6-a1f42cddf3d0","Combination of bone morphogenetic protein-2 plasmid DNA with chemokine CXCL12 creates an additive effect on bone formation onset and volume","Wegman, F.C.M. (TU Delft Transport and Planning; University Medical Center Utrecht); Poldervaart, M. T. (University Medical Center Utrecht); van der Helm, Y. J. (University Medical Center Utrecht); Oner, F. C. (University Medical Center Utrecht); Dhert, W. J. (Universiteit Utrecht); Alblas, J. (University Medical Center Utrecht)","","2015","Bone morphogenetic protein-2 (BMP-2) gene delivery has shown to induce bone formation in vivo in cell-based tissue engineering. In addition, the chemoattractant stromal cell-derived factor-1α (SDF-1α, also known as CXCL12) is known to recruit multipotent stromal cells towards its release site where it enhances vascularisation and possibly contributes to osteogenic differentiation. To investigate potential cooperative behaviour for bone formation, we investigated combined release of BMP-2 and SDF-1α on ectopic bone formation in mice. Multipotent stromal cellseeded and cell-free constructs with BMP-2 plasmid DNA and /or SDF-1α loaded onto gelatin microparticles, were implanted subcutaneously in mice for a period of 6 weeks. Histological analysis and histomorphometry revealed that the onset of bone formation and the formed bone volume were both enhanced by the combination of BMP-2 and SDF-1α compared to controls in cell-seeded constructs. Samples without seeded multipotent stromal cells failed to induce any bone formation. We conclude that the addition of stromal cellderived factor-1α to a cell-seeded alginate based bone morphogenetic protein-2 plasmid DNA construct has an additive effect on bone formation and can be considered a promising combination for bone regeneration.","Animal model; Bone; Bone morphogenetic protein-2; Controlled release; Gene therapy; Multipotent stromal cells; Stromal cell-derived factor-1α; Tissue engineering","en","journal article","","","","","","","","","","","Transport and Planning","","",""
"uuid:492dc4f3-9345-439e-9268-7c27c57e110b","http://resolver.tudelft.nl/uuid:492dc4f3-9345-439e-9268-7c27c57e110b","Basal Reinforced Piled Embankments","Van Eekelen, S.J.M.","Van Tol, A.F. (promotor); Bezuijen, A. (promotor)","2015","A basal reinforced piled embankment consists of a reinforced embankment on a pile foundation. The reinforcement consists of one or more horizontal layers of geosynthetic reinforcement (GR) installed at the base of the embankment. The design of the GR is the subject of this thesis. A basal reinforced piled embankment can be used for the construction of a road or a railway when a traditional construction method would require too much construction time, affect vulnerable objects nearby or give too much residual settlement, making frequent maintenance necessary. The GR strain needs to be calculated to design the GR. Multiplying this GR strain by the GR stiffness gives the tensile force, which needs to be smaller than the long-term GR tensile strength. The GR strain is calculated in two steps. Calculation step 1 divides the load – the weight of the embankment fill, road construction and traffic load – into two load parts. One part (load part A) is transferred to the piles directly. This part is relatively large because a load tends to be transferred to the stiffer parts of a construction. This mechanism is known as ‘arching’. The second, residual load part (B+C) rests on the GR (B) and the underlying subsoil (C). Calculation step 2 determines the GR strain on the basis of the result of step 1. Only the GR strips between each pair of adjacent piles are considered: they are loaded by B+C and may or may not be supported by the subsoil. The GR strain can be calculated if the distribution of load part B+C on the GR strip, the amount of subsoil support and the GR stiffness are known. An implicit result of this calculation step is the further division of load part B+C into parts B and C. Several methods for the GR design are available, all with their own models for calculation steps 1 and 2. The methods give results that differ immensely. The Dutch CUR226 (2010) and the German EBGEO (2010) adopted Zaeske’s method (2001). However, measurements that were published later (Van Duijnen et al., 2010; Van Eekelen et al., 2015a) showed that this method could be calculating much higher GR strains than those measured in practice, leading to heavier and more expensive designs than necessary. The objective of the present study was to establish a clearer picture of load distribution in a basal reinforced piled embankment and, on that basis, to develop and validate an analytical design model for the geosynthetic reinforcement in a piled embankment. The results were described in five papers published in the international scientific journal ‘Geotextiles and Geomembranes’. Those journal papers can be found in Chapters 2, 3, 4, 5 and Appendix A of this thesis (Van Eekelen et al., 2012a, 2012b, 2013, 2015a and 2011 respectively). Chapter 2 presents a series of twelve 3D experiments that were carried out at the Deltares laboratory. The scaled model tests were carried out under high surcharge loads to achieve stress situations comparable with those in practice. A unique feature of these tests was that load parts A, B and C could be measured separately, making it possible to compare the measurements with calculation steps 1 and 2 separately. In these tests (static load, laboratory scale), smooth relationships were obtained between the net load on the fill (surcharge load minus subsoil support) and several measured parameters such as load distribution and deformation. Consolidation of the subsoil resulted in an increase in arching (more A) and more tensile force in the GR (more B and more GR strain). The measured response to consolidation depends on the fill’s friction angle. A higher friction angle results in more arching during consolidation. One of the major conclusions based on the test series was that the load on a GR strip is approximately distributed as an inverse triangle, with the lowest pressure in the centre and higher pressure close to the piles. This conclusion was the basis for the remainder of this doctorate study and the development of the new calculation model. Chapter 3 considers calculation step 2. This chapter starts by comparing the measurements in the experiments with the calculation results of step 2 of the Zaeske (2001) model, which uses a triangular load distribution on the GR strip and considers the support of the subsoil underneath the GR strip only. It was found that Zaeske’s model calculates GR strains that are larger than the measured GR strains (approximately a factor of two for GR strains larger than 1%). Chapter 3 continues with the suggestion of two modifications to Zaeske’s step 2. Firstly, the load distribution is changed from a triangular to an inverse triangular load distribution. Secondly, the subsoil support is extended from the support by the subsoil underneath the GR strip to the subsoil underneath the entire GR between the piles. The new step 2 model with these modifications produces a much better fit with field measurements than Zaeske’s model. Chapter 4 considers calculation step 1, the arching. Additional tests were conducted for this purpose, varying factors such as the fill height. This chapter gives an overview of the existing arching models and introduces a new model. This Concentric Arches model (CA model) is an adaptation and extension of the models of Hewlett and Randolph (1988), and Zaeske (2001), which have been adopted in several European design guidelines. Some countries use piled embankments without GR. Introducing GR changes the load distribution considerably. A major part of the load is then exerted on the piles and the residual load is mainly exerted on the GR strips between the piles, with the load being distributed approximately as an inverse triangle. Chapter 4 explains the development of the load distribution as a result of continuing GR deflection; new small arches grow within the older larger ones. Smaller arches exert less load on their subsurface. This idea is related to the concentric arches of the new model, which gives an almost perfect description of the observed load distribution in the limit state situation. Furthermore, the new model describes the influence of the fill strength and embankment height correctly. Chapter 5 compares the existing, and the newly introduced, design models with measurements from seven full-scale projects and four series of scaled model experiments. Two of these seven field projects were conducted in the Netherlands and they were carried out in part for this doctorate research. One of the four experimental series – the one presented in Chapters 2 and 4 – was conducted specifically for the present research. The other measurements were reported earlier in the literature. The calculations were carried out using mean, best-guess values for the material properties. The calculation results from the CA model match the measurements much better than the results of the arching models of Hewlett and Randolph (1988), and of Zaeske (2001). The results of the CA model are also the closest match with the results of the 3D numerical calculations, as described in Van der Peet and Van Eekelen (2014). These authors also show that the new CA model responds better to changes in the fill friction angle than any of the other models considered. When there is no subsoil support, or almost no subsoil support, the inverse triangular load distribution on the GR strips between adjacent piles gives the best match with the measurements. When there is significant subsoil support, the load distribution is approximately uniform. This difference between the situation with or without subsoil support is understandable when one considers that most load is attracted to the construction parts that move least. In the cases with limited subsoil support, the load distribution that gives the minimum GR strain should be used to find the best match with the measurements. The GR strain calculated with Zaeske’s model is on average 2.46 times the measured GR strain. The GR strain calculated with the new model is on average 1.06 times the measured GR strain. The calculated GR strain is therefore almost a perfect match with the measured GR strain. The new Dutch CUR226 (2015) has therefore adopted the model proposed in this thesis.","piled embankments; geosynthetics; arching; Concentric Arches model; geosynthetic reinforcement; geo-engineering; geotechniques; road construction; infrastructure; design guideline","en","doctoral thesis","","","","","","","","2015-06-24","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:af1dcff9-1617-4835-a3a0-0469e1581337","http://resolver.tudelft.nl/uuid:af1dcff9-1617-4835-a3a0-0469e1581337","Essential validation methods for E. coli strains created by chromosome engineering","Krishnan, S.T.; Moolman, M.C.; Van Laar, T.; Meyer, A.S.; Dekker, N.H.","","2015","Background Chromosome engineering encompasses a collection of homologous recombination-based techniques that are employed to modify the genome of a model organism in a controlled fashion. Such techniques are widely used in both fundamental and industrial research to introduce multiple insertions in the same Escherichia coli strain. To date, ?-Red recombination (also known as recombineering) and P1 phage transduction are the most successfully implemented chromosome engineering techniques in E. coli. However, due to errors that can occur during the strain creation process, reliable validation methods are essential upon alteration of a strain’s chromosome. Results and discussion Polymerase chain reaction (PCR)-based methods and DNA sequence analysis are rapid and powerful methods to verify successful integration of DNA sequences into a chromosome. Even though these verification methods are necessary, they may not be sufficient in detecting all errors, imposing the requirement of additional validation methods. For example, as extraneous insertions may occur during recombineering, we highlight the use of Southern blotting to detect their presence. These unwanted mutations can be removed via transducing the region of interest into the wild type chromosome using P1 phages. However, in doing so one must verify that both the P1 lysate and the strains utilized are free from contamination with temperate phages, as these can lysogenize inside a cell as a large plasmid. Thus, we illustrate various methods to probe for temperate phage contamination, including cross-streak agar and Evans Blue-Uranine (EBU) plate assays, whereby the latter is a newly reported technique for this purpose in E. coli. Lastly, we discuss methodologies for detecting defects in cell growth and shape characteristics, which should be employed as an additional check. Conclusion The simple, yet crucial validation techniques discussed here can be used to reliably verify any chromosomally engineered E. coli strains for errors such as non-specific insertions in the chromosome, temperate phage contamination, and defects in growth and cell shape. While techniques such as PCR and DNA sequence verification should standardly be performed, we illustrate the necessity of performing these additional assays. The discussed techniques are highly generic and can be easily applied to any type of chromosome engineering.","chromosome engineering; Escherichia coli; recombineering; P1 phage transduction; strain validation; EBU plate assay; growth curve analysis; cell shape analysis; OA-Fund TU Delft","en","journal article","BioMed Central","","","","","","","","Applied Sciences","BN/Bionanoscience","","","",""
"uuid:addb5f6f-b76c-44d9-bc57-6e69e747014b","http://resolver.tudelft.nl/uuid:addb5f6f-b76c-44d9-bc57-6e69e747014b","Gender and Diversity in Engineering MOOCs, a first Appraisal","Ihsen, S.; Jeanrenaud, Y.; De Vries, P.; Hennis, T.A.","","2015","","online learning; MOOCs; gender and diversity; engineering education","en","conference paper","","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:09326701-94ee-4493-8c5a-2d96f9abc300","http://resolver.tudelft.nl/uuid:09326701-94ee-4493-8c5a-2d96f9abc300","The long-term response of rivers to engineering works and climate change","De Vriend, H.J.","","2015","Rivers respond to changes in their geometry or their controls in various ways and at a wide range of space and time scales. The response consists of changes in properties such as cross-sectional shape and area, slope, planform pattern, bed roughness and bed sediment composition. Usually, attention for the morphological impact of engineering works focuses on short-term effects. The usually much slower, but also much more persistent large-scale response is often ignored, or countermeasures are ineffective. In many cases this has led to extra maintenance costs, in some even to hazardous situations or disaster. This paper refreshes and extends long-existing but seemingly forgotten knowledge on large-scale river behaviour. It gives examples of impacts of engineering works, climate change and sea level rise, discusses potential countermeasures and gives a number of general conclusions on the large-scale morphological behaviour of lowland rivers.","floods & floodworks; hydraulics & hydrodynamics; river engineering","en","journal article","ICE Publishing","","","","","","","2016-06-17","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:d2798239-a5cc-482a-bb1e-7b1b87ab5697","http://resolver.tudelft.nl/uuid:d2798239-a5cc-482a-bb1e-7b1b87ab5697","A novel capsule-based selfrecovery system with a chloride ion trigger","Xiong, W.; Tang, J.; Zhu, G.; Han, N.; Schlangen, E.; Dong, B.; Wang, X.; Xing, F.","","2015","Steel is prone to corrosion induced by chloride ions, which is a serious threat to reinforced concrete structures, especially in marine environments. In this work, we report a novel capsule-based selfrecovery system that utilizes chloride ions as a trigger. These capsules, which are functionalized via a smart response to chloride ions, are fabricated using a silver alginate hydrogel that disintegrates upon contact with chloride ions, and thereby releases the activated core materials. The experimental results show that the smart capsules respond to a very low concentration of chloride ions (0.1 wt%). Therefore, we believe that this novel capsule-based self-recovery system will exhibit a promising prospect for self-healing or corrosion inhibition applications.","civil engineering; characterization and analytical techniques","en","journal article","Nature Publishing Group","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:945e15a0-faaa-48c7-8178-694c16be36f1","http://resolver.tudelft.nl/uuid:945e15a0-faaa-48c7-8178-694c16be36f1","Dynsem: A DSL for dynamic semantics specification","Vergu, V.A. (TU Delft Programming Languages); Neron, P.J.M. (TU Delft Software Engineering); Visser, Eelco (TU Delft Programming Languages)","","2015","The formal semantics of a programming language and its implementation are typically separately defined, with the risk of divergence such that properties of the formal semantics are not properties of the implementation. In this paper, we present DynSem, a domain-specific language for the specification of the dynamic semantics of programming languages that aims at supporting both formal reasoning and efficient interpretation. DynSem supports the specification of the operational semantics of a language by means of statically typed conditional term reduction rules. DynSem supports concise specification of reduction rules by providing implicit build and match coercions based on reduction arrows and implicit term constructors. DynSem supports modular specification by adopting implicit propagation of semantic components from I-MSOS, which allows omitting propagation of components such as environments and stores from rules that do not affect those. DynSem supports the declaration of native operators for delegation of aspects of the semantics to an external definition or implementation. DynSem supports the definition of auxiliary meta-functions, which can be expressed using regular reduction rules and are subject to semantic component propagation. DynSem specifications are executable through automatic generation of a Java-based AST interpreter.","Dynamic semantics; IDE; Interpreters; Modularity; Programming languages; Reduction semantics; Semantics engineering","en","conference paper","Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing","","","","","","","","","","Programming Languages","","",""
"uuid:3f41bd79-a6d6-46f1-8227-94f018a44f51","http://resolver.tudelft.nl/uuid:3f41bd79-a6d6-46f1-8227-94f018a44f51","Selection and development of innovative design alternatives: Ethical, social and uncertainty issues","Jacobs, J.F.","Osseweijer, P. (promotor); Van de Poel, I.R. (promotor)","2015","Innovative engineering design shapes the development of novel technologies and is ethically as well as socially relevant, because it affects what kind of possibilities and consequences will arise. A major challenge in engineering design work on innovative technologies is the multitude of uncertainties in the form of known unknowns, unknown unknowns, complexities, and ambiguities. The evaluation and generation of design concepts are general and essential parts of the design process in which value-laden considerations play a role. In order to contribute to the adequate dealing with social and ethical issues in innovative engineering design practice, this study has focused on the selection of the ‘best’ design concept taking into account ethical and social issues in the early design stages and the development of ethically and socially acceptable design concepts which are ‘robust’ with respect to relevant uncertainties. In the current literature little to no attention has been given to the way ethical and social issues can be addressed in innovative engineering design, therefore, an exploratory research approach has been employed to investigate this unexplored area. In a critical methodological analysis on frequently applied selection tools, it was found that the information availability in innovative design is the main limitation for calculative decision making methods that aim to support judgement formation. The faced uncertainties in engineering design restrict the tools in such a way that they produce incoherent outcomes, if used to choose a winning design concept. In the subsequent exploratory ethnographic studies the practical application of these selection tools was investigated. The results show that the design engineers use decision tools to support their value-laden judgement formation, but that the tool does not prescribe or describe the selection, so avoiding the identified methodological limitations of this kind of tools. In order to consider value-laden design criteria in the evaluation process, design engineers would be assisted by clear performance measures. The results indicate that current index methods, like the Fire and Explosion Index, do not provide adequate measures that are directly applicable in the selection of the ‘best’ design concept. Still they provide a good starting point to build upon, if practical considerations of innovative engineering design are taken into account. In a critical literature study, it was investigated what kind of valued laden aspects play a role in the development of design alternatives in the innovative field of nanotechnology. This literature study grounds the investigation into the development of design concepts that are robust with respect to the uncertainties that surround innovative design work. It indicates that approaches for robust and innovative engineering design work require plasticity towards specific applications and time scales of possible effects. Subsequent exploratory ethical inquiry indicates that existing approaches to address social and ethical issues, such as the Twelve Principles of Green Chemistry, can be adapted to new and innovative areas of engineering by abstraction and successive tailoring to the specific application. Design engineers can further be supported in the development of robust designs by approaches that allow for the evaluation of moral acceptability of design concepts under uncertainty. In this thesis it is shown that the moral acceptability can be evaluated by conceptualising the application of the designed artefact as a social experiment that needs to meet four normative conditions (absence of alternatives, controllability, informed involvement, continuous re-evaluation), and that such an evaluation is fruitful for innovative engineering design. All in all, it is concluded that design engineers can deal with social and ethical issues under uncertainty that is typical of innovative design by forming design judgement with the help of proper selection tools and development approaches in order to design a robust artefact that is adaptable in its configuration, flexible in its functioning, resilient to design assumptions, and resistant to changing circumstances.","Engineering Design; Selection Method; Arrows Impossibility Theorem; Decision Matrix; Conceptual Design; Innovative Engineering; Design for Values; Nanotechnology; Safety and Sustainability; Societal Experiment; Titanium Dioxide; Fire and Explosion Index","en","doctoral thesis","","","","","","","","2015-05-01","Applied Sciences / Technology, Policy and Management","Biotechnology / Values, Technology and Innovation","","","",""
"uuid:f1153242-f22b-472a-8c62-7bdda9433126","http://resolver.tudelft.nl/uuid:f1153242-f22b-472a-8c62-7bdda9433126","Modified bond model for shear in slabs under concentrated loads","Lantsoght, E.O.L.; Van der Veen, C.; De Boer, A.","","2015","Slabs subjected to concentrated loads close to supports, as occurring for truck loads on slab bridges, are less studied than beams in shear or slab-column connections in punching. To predict the shear capacity for this case, the Bond Model for concentric punching shear was studied initially. Modifications to this model resulted in the Modified Bond Model, which takes into account the enhanced capacity from the direct transfer of the load to the support, is able to deal with moment sign changes as occurring near continuous supports, and can take into account the reduction in capacity, resulting from the geometry when the load is placed close to the edge. The model is then compared to the results of experiments on slabs subjected to concentrated loads close to supports. As compared to the Eurocode and the ACI code, the Modified Bond Model leads to a significantly better prediction of the experimental results. The Modified Bond Model is one of the few models available to describe the shear capacity of slabs subjected to concentrated loads close to supports and can be used for design and assessment.","bridge engineering; concentrated loads; design; punching; shear; slabs","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:021a36a7-f7ce-406f-9e62-605e8de8ec6f","http://resolver.tudelft.nl/uuid:021a36a7-f7ce-406f-9e62-605e8de8ec6f","Integrated Coastal Management in the Province Ca Mau - Vietnam","Stoop, B.; Bouziotas, D.; Hanssen, J.L.J.; Dunnewolt, J.; Postma, M.G.","Groenewold, S.A. (contributor); Stive, M.J.F. (contributor); Giesen van de, N.C. (contributor)","2015","The province of Ca Mau is the southernmost part of Vietnam and the Mekong Delta. The water system of Ca Mau faces multiple challenges, both in its coastal zone and in its inland regions. the coastal zone in the province. In view of this, this study presents an integrated approach for combined coastal and inland water management in Ca Mau, under the scope of climate and socio-economic change. Firstly, an extensive literature study is performed on the current status of both the coastal zone and the inland water system. The objective of this study is to identify measures that contribute to a realization of a sustainable, durable environment that satisfies the protection and the socioeconomic needs of the inhabitants in the province of Ca Mau, in which coastal engineering, (inland) water management and land use can be integrated. In order to reach that identification, a holistic analytical approach that couples water engineering knowledge, systems modeling, horizon scanning and strategic analysis needs to be used; a second objective of this study is to formulate the right set of tools for this task and demonstrate their use, so that they can be adapted in a larger context in the future, beyond this study, both within Ca Mau but also in cross-provincial studies.","Coastal engineering; Watermanagement; Integration","en","report","","","","","","","","","Civil Engineering and Geosciences","","","","","9.1036, 10.0900"
"uuid:15505481-89e1-491c-848b-953291833c40","http://resolver.tudelft.nl/uuid:15505481-89e1-491c-848b-953291833c40","Flowscapes: Designing infrastructure as landscape","Nijhuis, S.; Jauslin, D.T.; Van der Hoeven, F.D.","","2015","Social, cultural and technological developments of our society are demanding a fundamental review of the planning and design of its landscapes and infrastructures, in particular in relation to environmental issues and sustainability. Transportation, green and water infrastructures are important agents that facilitate processes that shape the built environment and its contemporary landscapes. With movement and flows at the core, these landscape infrastructures facilitate aesthetic, functional, social and ecological relationships between natural and human systems, here interpreted as Flowscapes. Flowscapes explores infrastructure as a type of landscape and landscape as a type of infrastructure. The hybridisation of the two concepts seeks to redefine infrastructure beyond its strictly utilitarian definition, while allowing spatial design to gain operative force in territorial transformation processes. This academic publication aims to provide multiple perspectives on the subject from design-related disciplines such as architecture, urban planning and design, landscape architecture and civil engineering. It is a reflection of a multidisciplinary colloquium on landscape infrastructures held at the Faculty of Architecture and the Built Environment, Delft University of Technology, preparing grounds for in-depth discussions and future collaborations. The authors explore concepts, methods and techniques for design-related research of landscape infrastructures. Their main objective is to engage environmental and societal issues by means of integrative and design-oriented approaches. Through focusing on multidisciplinary design-related research of landscape infrastructures they provide important clues for the development of spatial armatures that can guide urban and rural development and have cultural and civic significance.","landscape infrastructure; design research; landscape architecture; urban design; architecture; civil engineering; green infrastructure; water infrastructure; transport infrastructure; infrastructural urbanism","en","book","TU Delft","","","","","","","","Architecture and The Built Environment","Urbanism","","","",""
"uuid:ea52472f-6bad-4ab0-8ca6-ebf445e41f2d","http://resolver.tudelft.nl/uuid:ea52472f-6bad-4ab0-8ca6-ebf445e41f2d","What preconceptions and attitudes about engineering are prevalent amongst upper secondary school pupils? An international study","Koycu, U.; De Vries, M.J.","","2015","n the Netherlands, as well as in many other countries, there is an increasing interest in implementing education about engineering as a part of general education at the upper secondary school level. In order to know what pupils at that level think about engineering, a study has been done to investigate their attitude towards and their concept of engineering. This study was done not only in the Netherlands but also in 39 other countries. In the preparation of the study, pupils were asked to draw concept maps of what they thought engineering was about. In the quantitative main part of the study, pupils were asked to respond to 33 Likert-type attitude items and 32 concept-items of the same type. A factor analysis was done in order to reveal the dimensions in the pupils’ attitude and concept. In contrast to studies carried out amongst students in lower secondary school levels, a fairly clear concept about engineering was found. The gender differences relating to engineering, found in lower secondary education, were not found in upper secondary education. The prevalent attitude of students towards engineering indicated a fairly positive image of engineering.","attitudes; concepts; engineering; upper secondary school","en","journal article","Springer","","","","","","","","Applied Sciences","","","","",""
"uuid:b6dcf405-1591-4202-b744-f833cef4541d","http://resolver.tudelft.nl/uuid:b6dcf405-1591-4202-b744-f833cef4541d","Porous Network Concrete: A bio-inspired building component to make concrete structures self-healing","Sangadji, S.","Schlangen, E. (promotor)","2015","The high energy consumption, its corresponding emission of CO2 and financial losses due to premature failure are the pressing sustainability issues which must be tackled by the concrete infrastructure industry. Enhancement of concrete materials and durability of structures (designing new infrastructures for longer service life) is one solution to overcome the dilemma. Concrete is a quasi-brittle material with properties that are high in compression but weak in tension, therefor concrete is prone to cracking. In the case that a continuous network of cracks is formed, the permeability of concrete will increase and the reinforcement bars may be open to the ambient atmosphere. This opening provides easy means for aggressive substances to enter into concrete and reach rebars which may start to corrode. Further cracks may threaten the tightness of the retaining structures, e.g. liquid containing structures tank wall, aqueducts, underground spaces, tunnels, etc., which undergo tensile forces. In these cases cracks may facilitate the flow of fluid – liquid or gas – into and out of the structures which considerably alters its serviceability, leads to unhealthy environments within a structure, and diminishes its functionality. In case the container or reservoir contains waste, highly toxic materials or radioactive materials, leakage through the concrete is catastrophic and unacceptable. One promising concept to design new concrete structures to achieve higher durability is incorporating self-healing mechanisms that are found in nature into the cement-based materials or the concrete structural element. If unavoidable cracks due to inherent brittleness in concrete could be self-sealed/healed/repaired, concrete will certainly serve longer and be more durable and sustainable. In general, on attempting to solve engineering problems, one can (always) seek inspiration from biology (nature). Though, borrowing nature’s idea to enhance our living environment is as old as humankind, the post-industrial technical advent makes the process more systematic and deliberate, hence makes use of bio-mimicry to solve problems and inspire innovation. Observing the domain of biology, there are several wound healing mechanisms found in nature: cut skin and bone fracture healing in human and animal, and plant response to injury. The present work takes inspiration from studies on bones of present-day mammals and birds and its healing mechanism. Two of appropriate principles that might be constructive are identified; (1) bone morphology comprises of cortical (solid) bone and trabecular (spongious) bone and (2) a feedback loop process is present in the remodelling and healing process. These two principles formed the basis for the development of a healable concrete material and for a method for healing it with healing agents. The idea behind this is that cortical bone may be mimicked with solid concrete and trabecular bone may be imitated by porous concrete. The combination of the two types of concrete resembles Porous Network Concrete, a bone-like concrete able to self-heal by the mechanism of feedback loop. These are the points addressed in the chapter 1 which explores the success story of concrete in serving society and civilization for millennia, the present challenge to make modern concrete more durable, and the bio-inspired solution of self-healing concrete Porous Network Concrete (PNC) is a hybrid system in which high permeability porous concrete is embedded in the interior or exterior of normal dense concrete. The porous network core constitutes alternate means for [1] channelling temporary or permanent materials to form a dense layer in the later stage and [2] distributing healing agent from the point of injection to cracks in the concrete main body. In chapter 2 the concept of the PNC is elaborated by setting up criteria and realized by creating a fabrication procedure. The production process – the making of the PNC – follows the current standard for both of the main and porous part and seemingly there is no complicated fabrication procedure. PNC characterization was carried out to study its pore and mechanical properties. The autonomous healing mechanism in the PNC is designed by incorporating the feedback mechanism; once a certain crack width is sensed, an action to heal takes place. As a proof-of-concept, in chapter 3, a simple and intuitive approach to design a feedback system for PNC self-healing mechanism has been carried out. When a concrete structure receives loads and builds up internal stress, it deflects, cracks and deforms. Once the crack mouth opening reaches a certain prescribed value the healing agent is injected automatically. The proposed working principle is verified by mechanical and leakage (permeability, infiltration) testing. The solidification process of the self-healing agent is important and even critical for the success of the healing strategy and mechanism designed. Instead of developing new healing agent and investigating its behaviour, this present study aims to examine the effectiveness and efficiency of the healing process in the Porous Network Concrete with different classes of agents. Three groups of healing agents are then studied and its healing efficiency is tested by leakage and mechanical testing. The first type of agent is a single- and double-component chemical based which mostly works through poly-condensation or cross-link polymerization upon contact with the atmosphere, with the concrete matrix or within the reactants. In this case, epoxy resin is used. The second healing agent used is grout material made of a cementitious powder mix. Cementitious grout material can be thought of as healing agent for concrete structures since it functions as crack sealant and void filler with the objective to restore structural integrity. The use and healing performance of PNC by both healing agents is discussed in chapter 4. The third agent is bacteria-based repair solution. It contains alkaliphilic bacteria able to facilitate bio-mineralization, nutrients and transport solution. It was originally developed as a bio-based repair material for cracked concrete. This is discussed in the dedicated chapter 5. It has been demonstrated in this thesis that the Porous Network Concrete has a good prospect in making concrete structural elements self-healing. This is the concluding point presented in the final chapter. Some recommendations for improving the work are presented such as; modelling work, larger and realistic experimental campaign and improved damage sensing.","concrete; porous concrete; porous network concrete; self-healing concrete; biomimetic; bio-inspired engineering; closed-loop feedback; autonomous healing mechanism; autogeneous healing mechanism","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:7e3ea63e-3f28-4f9d-a340-95acc8828763","http://resolver.tudelft.nl/uuid:7e3ea63e-3f28-4f9d-a340-95acc8828763","Towards an action-oriented model for first year engineering student success: A mixed methods approach","Van den Bogaard, M.E.D.","Verbraeck, A. (promotor); De Graaff, E. (promotor)","2015","","engineering education; student retention; student success","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","Systems engineering","","","",""
"uuid:bdaad5cf-1995-4cb0-81db-7aaff65b9289","http://resolver.tudelft.nl/uuid:bdaad5cf-1995-4cb0-81db-7aaff65b9289","'Doing more with less' or 'doing less with less'? Assessing EU cohesion policy's financial instruments for urban development","Dabrowski, M.M.","","2015","In the context of a severe economic crisis and austerity, new ideas were put forward to reform cohesion policy to enhance its effectiveness and the return on investment. Among them, financial engineering instruments, such as JESSICA, expected to offer a means to ‘do more with less’ in this difficult budgetary context. In the case of such instruments, EU funds are not offered as grants co-financing investment projects, but rather are used to provide repayable assistance to projects, a form of support. Such revolving funds approach is in stark contrast with the grant-based assistance typically offered as part of EU cohesion policy and was expected to increase the sustainability and effectiveness of interventions. But does it fulfil those expectations? This paper examines JESSICA through the conceptual lens of policy instruments literature. It verifies whether JESSICA is actually fit for its purpose of supporting sustainable urban development. It also gauges the impacts of instrument on the behaviour of the actors involved in its implementation at the sub-national level. The findings indicate that JESSICA is a flawed and overly complex instrument that instead of doing ‘more with less’ only allows for achieving ‘less with less’. However, it still exerts a positive influence on the sub-national authorities involved by promoting cross-sectoral interactions and facilitating learning. It also promotes a change in the approach to EU cohesion policy and public investment more generally, putting more emphasis on economic viability of investment.","EU cohesion policy; JESSICA; financial engineering instruments; urban development; policy instruments; tools of government","en","journal article","Taylor & Francis","","","","","","","","Architecture and The Built Environment","Urbanism","","","",""
"uuid:75ea46bc-deab-4259-9a73-0ca420cb94f6","http://resolver.tudelft.nl/uuid:75ea46bc-deab-4259-9a73-0ca420cb94f6","Hot Mix Asphalt Recycling: Practices and Principles","Mohajeri, M.","Molenaar, A.A.A. (promotor); Van de Ven, M.F.C. (promotor)","2015","Hot mix asphalt recycling has become common practice all over the world since the 1970s because of the crisis in oil prices. In the Netherlands, hot recycling has advanced to such an extent that in most of the mixtures more than 50% of reclaimed asphalt (RA) is allowed. These mixtures with such a high RA content are produced in a batch plant to which a parallel drum is attached. In this drum RA is pre-heated to approximately 130°C. Since 2007 another hot mix recycling techniques became available in which RA is mixed in cold and moist condition in contrary to conventional methods. It is a so called double barrel drum mixer. In this method virgin aggregates are superheated in the inner drum and mixed with cool and moist RA and fines and virgin bitumen in the outer drum. In both cases, double drum and partial heating methods, the virgin aggregates have to be pre-heated to higher temperatures than with mixtures without RA in order to achieve a mixing temperature of around 170°C. Dependent on RA amount, moisture, pre-heating, etc. in the batch plant the virgin aggregates have to be pre-heated to around 300° C and in the double barrel drum to around 500°C. These high temperatures have led to concerns about the quality of the produced mixtures. Since 2008, a new Dutch specification system for asphalt mixtures is in place in line with the European standards (EN13108 series). The new regulation gives contractors freedom to select their own material such as bitumen grade and the amount of recycling; however, in return it makes them responsible for the quality of the mixture. The mixture should fulfill the requirement of fundamental performance characteristics of the mixtures such as resistance to fatigue and permanent deformation. In this research two major questions have been investigated. One of the questions is whether these high temperatures have a negative effect on the bituminous binder, while the other important question is whether the RA binder will blend totally with the virgin binder that is added. The focus of this research was on four objectives. The first objective was to develop a laboratory mixing method to simulate the real recycling process in the field. The second objective was to assess the effect of the double barrel drum on the mixture quality in comparison with conventional batch plant. Third, it was aimed to measure the blending degree between two binders. And finally, to increase the understanding of the mechanism behind blending RA binders with virgin bitumen, with focus on their micro structure. To cover all research topics, this dissertation is organized in two parts in which the first part is devoted to laboratory and field mixture evaluation while the second part is presenting the exploratory research on the fundamental aspects of blending. Research in part 1 is conducted in two phases, laboratory simulation and field experimentation. The conventional partial warming recycling method (PW) the upgraded double drum mixing method (UPG) were simulated in the lab and the quality of mixtures were compared with the standard mixing method (SM) in the lab at different RA content and different moisture content. This research showed that higher percentages of RA results in higher stiffness and lower fatigue life. However in the UPG method with 4% moisture and 60% RA, the mixture became remarkably lower in stiffness and durable against fatigue. This might be because of the lack of blending or the effect of foaming of bitumen. It was concluded that the UPG method could not effectively be simulated in the lab. In the next experimental phase of the study, three identical mixtures were produced with 50% RA and 4.3% bitumen. One mixture was produced in a batch plant (BB) while the second one was mixed using a double drum mixer by the same contractor (A). The third mixture was produced in the laboratory (L) using a lab pugmill mixer. The comparison between three mixtures shows that mixture L has a higher stiffness than A and BB. Mixture BB has as slightly higher stiffness than A. Furthermore, mixture A has the lowest stiffness which is most probably due to the system of cold and moist RA feeding into the double drum system. Besides the 4PB fatigue and stiffness test, monotonic uniaxial tension (UT) and compression (UC) tests were performed to be used in material modeling and to determine a fatigue endurance limit. The limit value of the stress ratio parameter (Rlimit) was determined which is useful in the determination of the endurance limit in a three-dimensional state. It shows that different mixing methods lead to different endurance limits. It turns out that the plant produced mixture has a higher endurance limit than the laboratory mixture. In this research an infrared thermography method was used in every material preparation stage. The temperature homogeneity of the mixtures in the lab and in the field was investigated. It proved to be a useful method in visualizing the temperature exchange during mixing and compaction. In Part 2, the effect of superheating aggregates is studied by simulating RA and real aggregates with glass beads and artificial aged binder. The stage extraction method was evaluated in this research with respect to size and shape of aggregates. The blending and diffusion mechanism between old and new bitumen is studied at the microstructure level by means of Nano indention and Nano-CT scanning. The morphology of different types of bitumen was detectable by these techniques; however the blending zone couldn’t be characterized.","hot mix asphalt; recycling; blending; bitumen; reclaimed asphalt; nano indentation; fatigue; double drum mixer; superheated aggregates; nano CT scanning; microstructure of bitumen; asphalt tensile strength; asphalt compressive strength; fatigue endurance limit; batch plant; parallel partial warming; road engineering; infrared thermography; DSR; FTIR","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:63bd3202-b39e-4095-9970-2efbef3d8e69","http://resolver.tudelft.nl/uuid:63bd3202-b39e-4095-9970-2efbef3d8e69","Mathematical Modelling of Nucleating and Growing Precipitates: Distributions and Interfaces","Den Ouden, D.","Vuik, C. (promotor); Sietsma, J. (promotor); Vermolen, F.J. (promotor)","2015","Steels with higher strength and better formability are increasingly required by the automotive industry because they can provide higher safety, reduce energy consumption and thus lead to a better environmental protection. To meet these requirements, it is a sustainable effort for steel industry to develop high strength formable steels. One of the commonly used methods for such a development is micro-alloying, that is, the addition of micro-alloying elements such as niobium, vanadium and titanium at a level of only a few hundredths of a weight percent results in a very pronounced strength-enhancing effect on the steels, provided that an appropriate heat treatment is applied. It is understood that the strength-enhancing effect primarily arises from a strong reduction in the average grain size of the ferrite, originating from the grain-refining effect during the austenisation treatment. The reason for the grain-refining effect is that the micro-alloying elements have a very strong affinity for the interstitial elements such as carbon and nitrogen, leading to the precipitation of extremely fine and widely distributed precipitates. The existence of the precipitates prevents the growth of austenite grains by means of Zener pinning. Therefore it is an essential issue for steel industry to have an accurate control of the nucleation and growth of the precipitates during thermomechanical processing of the steels. In this thesis we focus on several models describing the nucleation and growth of precipitates. This PhD research focusses on this subject.","Mechanical, Maritime and Materials Engineering; MSE","en","doctoral thesis","M2i","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Delft Institute of Applied Mathematics","","","",""
"uuid:1f204a6e-8762-4a10-a2de-f63a669e0c84","http://resolver.tudelft.nl/uuid:1f204a6e-8762-4a10-a2de-f63a669e0c84","Method for lean engineering design process","Beelaerts van Blokland, W.W.A.","Lodewijks, G. (advisor)","2015","","Railway interlocking systems; lean manufacturing; complexity; engineering operations performance","","conference paper","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:09a60e70-9d0d-4aa8-93b1-50c1ee2a4fa0","http://resolver.tudelft.nl/uuid:09a60e70-9d0d-4aa8-93b1-50c1ee2a4fa0","Two-part modelling approach for ship engine simulations","Godjevac, M.","de Vos, P. (advisor)","2015","","First principle model; diesel engine model; system modelling; ship propulsion system","","conference paper","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:bcee587e-bb5b-42f8-a9b7-1de18b8f0cb2","http://resolver.tudelft.nl/uuid:bcee587e-bb5b-42f8-a9b7-1de18b8f0cb2","Predicting structural disasters with radar interferometry","Terwel, K.C. (TU Delft Steel & Composite Structures); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning); Waning, H","Bruhwiler, E (editor)","2015","Radar interferometry is a technique which can observe the earth’s surface during day and night time. It makes uses of thousands of pulses per second that are transmitted by satellites and reflected by the surface of, for instance, structures. By analyzing the data it is possible to measure displacements of the surface within millimeter precision. For the building industry this might be a promising technique, for monitoring buildings or for forensic engineering. Variables that might be monitored are the displacements of roofs, of balconies or the settlements of buildings. In addition, the technique might be a tool which can be used for forensic investigations. This paper will discuss the possibilities and limitations of radar interferometry for both building monitoring and forensic engineering. The method is expected to be especially useful for measuring soil displacements and the resulting settlements of structures.","radar interferometry; structural health monitoring; forensic engineering; new technologies","en","conference paper","IABSE","","","","","Author Manuscript","","","","","Steel & Composite Structures","","",""
"uuid:54187ea6-6426-4e48-8ef1-1cdcf5a6657b","http://resolver.tudelft.nl/uuid:54187ea6-6426-4e48-8ef1-1cdcf5a6657b","Using C language extensions for developing embedded software: A case study","Völter, M (Itemis AG); van Deursen, A. (TU Delft Software Technology); Kolb, Bernd (Itemis AG); Eberle, Stephan (Itemis AG)","","2015","We report on an industrial case study on developing the embedded software for a smart meter using the C programming language and domain-specific extensions of C such as components, physical units, state machines, registers and interrupts. We find that the extensions help significantly with managing the complexity of the software. They improve testability mainly by supporting hardware-independent testing, as illustrated by low integration efforts. The extensions also do not incur significant overhead regarding memory consumption and performance. Our case study relies on mbeddr, an extensible version of C. mbeddr, in turn, builds on the MPS language workbench which supports modular extension of languages and IDEs.","Case Study; Domain-Specific Language; Embedded Software; Language Engineering; Language Extension","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","Software Technology","","","",""
"uuid:d7e1f3b9-c06f-46a9-bf49-1984427aa365","http://resolver.tudelft.nl/uuid:d7e1f3b9-c06f-46a9-bf49-1984427aa365","A heuristic to understand curriculum change: Towards comparing 3 course programme overhauls within the Dutch 3TU coalition","van den Bogaard, M.E.D. (TU Delft System Engineering); Verkroost, M.J. (University of Twente); Oude Alink, C. (University of Twente); Schellen, H.L. (Eindhoven University of Technology)","","2015","The 3TU coalition consists of the three universities of technology in the Netherlands: Delft, Eindhoven and Twente, which are all all-round engineering universities. The universities decided to strengthen engineering research and education in the Netherlands by collaborating and learning from each other in the Centre for Engineering Education (CEE). In the CEE, the three universities work on joint research and development projects with a special focus on studying and enhancing engineering education in a structured way. The project reported in this paper is set up within the framework of the 3TU CEE and pertains to curriculum change in the three participating technical universities. . In recent years the three universities overhauled their bachelor programmes to improve the learning experiences of the students and, ultimately, improve graduation rates and diminish time to graduation. Such curriculum changes are usually not documented in such a way that the process and outcomes can be easily understood and that limits the capacity of an organisation to learn from them. In this CEE research project, the overhaul processes are mapped, evaluated and compared ex post facto. The goal of this effort is to collect and share experiences and ideas on course programme development and implementation and to isolate effective practices. To achieve this, an ontology of factors influencing a curriculum change process needed to be developed, to allow comparison across the research sites. This ontology was designed to help map and evaluate effective practices for design and implementation of changes in course programmes, but also to help understand what interventions are effective in terms of improving student success. The special focus in this project is the uniqueness of developing engineering course programmes. Engineering is an interdisciplinary field where scientific knowledge is applied knowledge to design solutions to solve complex problems in an engineering kind of way (see e.g. Godfrey Parker, 2010; Graham, 2012). This creates many challenges for those who design course programmes, but also forthose who implement such a programme. In this paper we describe the elements of the ontology and the scientific basis for inclusion. We also describe how the ontology fits in with the research methodology of the project.","Curriculum design; curriculum evaluation; engineering education","en","conference paper","","","","","","","","","","","System Engineering","","",""
"uuid:6ca7a27b-9272-4da6-939e-85cbd1a1082b","http://resolver.tudelft.nl/uuid:6ca7a27b-9272-4da6-939e-85cbd1a1082b","Cross Institutional Comparison of Curricular Change in Dutch Engineering Bachelor Programmes","Klaassen, R.G. (TU Delft OLD E&SS education center FOCUS; 4TU.Centre for Engineering Education); Brans, C.H.T.A. (Eindhoven University of Technology); Gommer, E.M. (University of Twente)","","2015","The Netherlands has three Universities of Technology. Delft University of Technology
(TU-D) in the West of the country, the University of Eindhoven (TU/e) in the south of
the country and Twente University (UT) in the East of the country. All these
Universities started a bachelor innovation process more or less independently and at
the same time. These innovations were instigated under the pressure of
governmental measures to improve success rates and educational quality.","Curriculum Development; Engineering Education","en","conference paper","","","","","","","","","","","OLD E&SS education center FOCUS","","",""
"uuid:c9aff527-a262-46e3-a9f3-da1086503c90","http://resolver.tudelft.nl/uuid:c9aff527-a262-46e3-a9f3-da1086503c90","Essential validation methods for E. coli strains created by chromosome engineering","Tiruvadi Krishnan, S. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft); Moolman, M.C. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft); van Laar, T. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft); Meyer, A.S. (TU Delft BN/Anne Meyer Lab; Kavli institute of nanoscience Delft); Dekker, N.H. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft)","","2015","Background: Chromosome engineering encompasses a collection of homologous recombination-based techniques that are employed to modify the genome of a model organism in a controlled fashion. Such techniques are widely used in both fundamental and industrial research to introduce multiple insertions in the same Escherichia coli strain. To date, λ-Red recombination (also known as recombineering) and P1 phage transduction are the most successfully implemented chromosome engineering techniques in E. coli. However, due to errors that can occur during the strain creation process, reliable validation methods are essential upon alteration of a strain's chromosome. Results and discussion: Polymerase chain reaction (PCR)-based methods and DNA sequence analysis are rapid and powerful methods to verify successful integration of DNA sequences into a chromosome. Even though these verification methods are necessary, they may not be sufficient in detecting all errors, imposing the requirement of additional validation methods. For example, as extraneous insertions may occur during recombineering, we highlight the use of Southern blotting to detect their presence. These unwanted mutations can be removed via transducing the region of interest into the wild type chromosome using P1 phages. However, in doing so one must verify that both the P1 lysate and the strains utilized are free from contamination with temperate phages, as these can lysogenize inside a cell as a large plasmid. Thus, we illustrate various methods to probe for temperate phage contamination, including cross-streak agar and Evans Blue-Uranine (EBU) plate assays, whereby the latter is a newly reported technique for this purpose in E. coli. Lastly, we discuss methodologies for detecting defects in cell growth and shape characteristics, which should be employed as an additional check. Conclusion: The simple, yet crucial validation techniques discussed here can be used to reliably verify any chromosomally engineered E. coli strains for errors such as non-specific insertions in the chromosome, temperate phage contamination, and defects in growth and cell shape. While techniques such as PCR and DNA sequence verification should standardly be performed, we illustrate the necessity of performing these additional assays. The discussed techniques are highly generic and can be easily applied to any type of chromosome engineering.","Cell shape analysis; Chromosome engineering; EBU plate assay; Escherichia coli; Growth curve analysis; P1 phage transduction; Recombineering; Strain validation","en","journal article","","","","","","","","","","","BN/Nynke Dekker Lab","","",""
"uuid:0658f32f-ba7e-4bfb-b1fe-44e73d0a2ecf","http://resolver.tudelft.nl/uuid:0658f32f-ba7e-4bfb-b1fe-44e73d0a2ecf","Design for values in engineering","van de Poel, I.R. (TU Delft Values Technology and Innovation)","","2015","Values have probably always played a role in engineering design. However, in current practices and design methods, the attention for values in engineering design tends to be implicit and unsystematic. Establishing Design for Values in engineering would require overcoming this situation. This contribution discusses which values play a role in engineering and engineering design, describes existing methods and experiences with Design for Values in engineering, and explores how values can be integrated into engineering design and existing design methods, in particular quality function deployment (QFD). It identifies four challenges for Design for Values in engineering: (1) discovery of the values to be included in engineering design; (2) translation of these values into engineering characteristics; (3) choice among design options that meet different values to different degrees; and (4) verification of whether a design indeed embodies the intended values.","Design for values; Design for X; Design methods; Engineering design; QFD; Values","en","book chapter","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2015-11-08","","Values Technology and Innovation","Ethics & Philosophy of Technology","","",""
"uuid:57e2bef2-18bc-4014-8e34-c10d66c6a40a","http://resolver.tudelft.nl/uuid:57e2bef2-18bc-4014-8e34-c10d66c6a40a","An Application of the IPROD Software Framework to Support the Product Development Process in the Automotive and Aerospace Domain","Hoogreef, M.F.M.; Van Dijk, R.E.C.; La Rocca, G.; d'Ippolito, R.","","2014","The Product Development Process (PDP) of manufacturing companies requires the efficient management of huge amounts of data from different sources and their integration in the sub-processes that compose the product development chain. This is a very challenging endeavor for which an integrated approach does not yet exist. The EC FP7 Project iProd aims at filling this void, by developing a flexible and service-oriented software framework, supported by a knowledge base that is structured by means of ontologies, to improve the efficiency and the quality of the PDP in the preliminary design phase. This paper discusses the first prototype of this software framework. The logic, overall software architecture and some of the implementations details of the framework are described. The functionalities of the software framework are demonstrated by means of two use-cases from two different domains, i.e. the automotive domain, represented by the development process of a car door, and the aerospace domain, represented by the development process of a rudder for a business jet. Preliminary testing, using the first prototype, indicates that the application of the framework to the two use-cases can yield benefits in terms of a reduction in development time in the preliminary design phase and results in product quality improvements, by having additional time for more design iterations to increase the maturity level during this phase. However, the framework is to be improved in terms of reliability, efficiency and maintainability. These improvements will be done during the development of two more software prototypes.","capturing product information; knowledge engineering; knowledge management; industrial workflow enhancement; ontologies; knowledge-based technologies to support the product development process","en","conference paper","TMCE","","","","","","","","Aerospace Engineering","Aerodynamics, Wind Energy & Propulsion","","","",""
"uuid:4664e1b9-3083-4ecb-86ff-8bb94cb529a3","http://resolver.tudelft.nl/uuid:4664e1b9-3083-4ecb-86ff-8bb94cb529a3","Dynamically loaded beam failure under corroded conditions","Veerman, R.P.; Koenders, E.A.B.","","2014","De-icing salts, used on roads in heavy winters, may enter reinforced concrete (RC) structures via its capillary pore system or via cracks, initiating reinforcement corrosion and reducing its remaining service-life. Vehicles passing real bridges exert a dynamic impact action that might activate a fatigue failure mechanism. In order to generate more knowledge on the interaction between corrosion and fatigue, a four-point-bending test setup is developed where two lab-scale RC beams are loaded simultaneously. In this setup, RC beams are loaded dynamically, while for one of the beams, corrosion is accelerated by means of a chloridesolution bath mounted on top of it. The second beam, which is the control, is only exposed to tap water. Many test repetitions are foreseen, but so far, three tests are conducted using two different loading levels. It turned out that the reinforcement bar, which corroded due to chloride exposure, failed first in all cases. This paper reports results of the failure mechanism whereby forensic engineering was used to examine the interaction between corrosion and fatigue, and that this might result in a harmful undesirable failure mechanism. The results, therefore, should also be considered for service-life design predictions of infrastructure.","corrosion; cracks; forensic engineering; failure mechanism; fatigue; reinforced concrete","en","conference paper","HPC Union","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:e523bc7b-6a00-4c0d-9d94-7ad9e878a94b","http://resolver.tudelft.nl/uuid:e523bc7b-6a00-4c0d-9d94-7ad9e878a94b","Q board interviews: An effective method to research user opinions","Wiegers, T.; De Lange, C.J.M.; Vergeest, J.S.M.","","2014","Q board interviews can be applied as an effective method to get insight in the opinions of participants. Q board interviews form the interviewing part of Q methodology. Q methodology can be used to identify typical sets of opinions. However, in many studies, the research goal is to order opinions and see which ones play the most important roles, instead of identifying groups of people with similar opinions. In such cases, full Q methodology is not required. Yet, the Q board interviewing method has a number of characteristics that are also advantageous in such situations. Therefore, we decided to apply Q board interviews, although our goal was not to do factor analysis. With Q board interviews, participants order pre-formulated statements. Besides, participants are encouraged to provide background information. This enables them to bring in issues that go beyond the fixed set of statements. Because of this combination, Q board interviews stimulate engagement of the participants, without making the interview time consuming. The paper describes how Q board interviews were used by students of the course Social Cohesion Design and how the application of Q board interviews functioned as a preparation for applying Q methodology in the second stage of the course.","research aspects in engineering; human and social aspects; opinion research; Q methodology; social cohesion design; participatory research","en","conference paper","Delft University of Technology","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:d94c540e-cf9b-410d-9286-3895f461842d","http://resolver.tudelft.nl/uuid:d94c540e-cf9b-410d-9286-3895f461842d","Analysis of the structural design process of the adaptive reuse of building structures","Pasterkamp, S.","","2014","In the field of structural building engineering there is a market shift taking place as a result of the growing number of buildings that are listed as cultural heritage, secularization, the economic situation and the increasing office vacancy rate in Europe and the US. More and more structural engineering firms that were designing and constructing new buildings now move to maintenance and adaptive reuse of existing building structures. But how does this shift influence the way in which engineering firms work? What is the influence of adaptive reuse of existing building structures on the structural design process? Unlike fields like architecture and especially industrial design that have a strong design tradition, in structural engineering until now engineering design has been regarded more as a craft that has to be learned in practice than as science. As a result of this, arguments to answer those questions are hard to find in literature (with a few notable but little cited exceptions such as the paper How designs develop by S.J. Macpherson c.s.[2]). To fill this gap an analysis has been made of the way in which the design process of adaptive reuse projects is supposed to work according to literature and professional associations, and of the way it really works in practice. Grounded theory method is used to generate concepts to explain the way structural designers work in such projects. Preliminary results show that standard descriptions of the engineering design process (generally from abstract to detail as for instance suggested in The Architect’s Handbook by J.A. Demkin c.s.[3]) do not correctly describe the way in which this design process really works. Not only did the redesign process of existing building structures not work as expected by both clients and practitioners; even the structural design process of new building projects can be seen in a different light. It is expected that the results of this research eventually might lead to different contracts between clients and engineering firms in the future.","adaptive reuse; buildings; engineering design; grounded theory","en","conference paper","Instituto de Ingenieria UNAM","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:210df1ab-21cd-4447-ae14-1f2d8958d970","http://resolver.tudelft.nl/uuid:210df1ab-21cd-4447-ae14-1f2d8958d970","Human Research Ethics Committees in Technical Universities","Koepsell, D.R.; Brinkman, W.P.; Pont, S.C.","","2014","Human research ethics has developed in both theory and practice mostly from experiences in medical research. Human participants, however, are used in a much broader range of research than ethics committees oversee, including both basic and applied research at technical universities. Although mandated in the United States, the United Kingdom, Canada, and Australia, non-medical research involving humans need not receive ethics review in much of Europe, Asia, Latin America, and Africa. Our survey of the top 50 technical universities in the world shows that, where not specifically mandated by law, most technical universities do not employ ethics committees to review human studies. As the domains of basic and applied sciences expand, ethics committees are increasingly needed to guide and oversee all such research regardless of legal requirements. We offer as examples, from our experience as an ethics committee in a major European technical university, ways in which such a committee provides needed services and can help ensure more ethical studies involving humans outside the standard medical context. We provide some arguments for creating such committees, and in our supplemental article, we provide specific examples of cases and concerns that may confront technical, engineering, and design research, as well as outline the general framework we have used in creating our committee.","engineering; design; research ethics; human subjects; technical university","en","journal article","SAGE","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:852175ad-bcdc-4fe4-ae01-271f2405fd91","http://resolver.tudelft.nl/uuid:852175ad-bcdc-4fe4-ae01-271f2405fd91","Reliability analysis of the Red River dikes system in Viet Nam","Pham Quang, T.","Vrijling, J.K. (promotor); Van Gelder, P.H.A.J.M. (promotor)","2014","This dissertation presents the applications of probabilistic-based frameworks in geotechnical and hydraulic engineering, for the assessment of the Red River dikes in Viet Nam. Dike along rivers often spread over the deltaic environment and its earthen structures are parts of a long civilian history, from hundreds to thousands of years. Uncertainties of soil properties (resistance) of the dike embankment and its foundation, and contribute to the probability of failure under a given water level. Water level (load) composes uncertainty that relates to the variability of hydraulic boundary condition as well as the statistics at gauging stations. The probabilistic-based framework already proved its benefits by combining the uncertainties from both load and resistance, which will be applied in the study area. The calculation results indicate that during a long duration flood, the Red River dike system will be mostly threatened by piping. The proposed models of piping dealing with time have been calibrated by an actual dike failure, which are also applied to the assessment of the Red River dike system. Model factor significantly shows its benefits in the analysis of sand boils and some related phenomena. Overall, the Red River dikes in the Ha Noi area have a lower safety level than that we expected, which is indicated by a system reliability index when taking all failure mechanisms and dike stretches into account.","geotechnical reliability; flood defence; red River dike; piping; uplift; geotechnical engineering; hydraulic engineering","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:c11ff40a-cf64-4459-95df-6908b6245354","http://resolver.tudelft.nl/uuid:c11ff40a-cf64-4459-95df-6908b6245354","Smart needles for percutaneous interventions","Henken, K.R.","Dankelman, J. (promotor); van den Dobbelsteen, J.J. (copromotor)","2014","The development of advanced needles for diagnostic and therapeutic purposes such as ablation and brachytherapy in the liver has offered minimally invasive therapies to patients that were previously untreatable. This thesis focuses on accurate placement of such needles guided by magnetic resonance imaging (MRI) to maximize the effect of the treatment and to minimize unwanted side-effects. To this end, an MRI-compatible steerable needle is developed which consists of a cable-actuated tip and a passively flexible shaft. The trajectory of this needle can be adjusted after the needle has been inserted. In addition, shape sensing based on optical strain sensors (fiber Bragg gratings or FBGs) is investigated aiming at feeding back information about the position and orientation of the needle tip in real-time. This is essential for accurate targeting, particularly when the needle trajectory is curved. Finally, steerability and shape sensing are integrated in a robotic system for needle steering in MRI-guided percutaneous interventions in the liver. The master-slave system comprises a steerable needle equipped with FBGs for tracking and a piezoelectric actuator unit. Needle insertion and steering is controlled by the physician through a master device, while FBG-based visual feedback of the needle shape is provided.","needle; robotics; FBG; biomedical engineering; sensors; MRI; medical instruments; shape sensing; needle steering","en","doctoral thesis","","","","","","","","2015-09-30","Mechanical, Maritime and Materials Engineering","BioMechanical Engineering","","","",""
"uuid:c0dd0308-5238-420a-ad67-2e195d8278a6","http://resolver.tudelft.nl/uuid:c0dd0308-5238-420a-ad67-2e195d8278a6","State on the art of computational tools for conceptual structural design","Rolvink, A.; Coenders, J.L.; Mueller, C.","","2014","This paper presents a review of existing research, projects, developments and applications in the domain of design tools for conceptual structural engineering. The availability of these tools and research into software for conceptual structural design stages has shown a number of interesting developments over the last past few years. The purpose of this investigation is to understand the requirements for software for the early stages of structural design. It investigates the current conceptual design practice, discusses a number of novel trends, and characterizes the relative effectiveness of the available technologies in relation to the nature of the early design stages.","structural engineering; computational tools; conceptual design; software development; collaboration","en","conference paper","International Association for Shell and Spatial Structures (IASS)","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:d1746a1a-b4a9-4432-809e-e970528b868c","http://resolver.tudelft.nl/uuid:d1746a1a-b4a9-4432-809e-e970528b868c","Structured automated code checking through structural components and systems engineering","Coenders, J.L.; Rolvink, A.","","2014","This paper presents a proposal to employ the design computing methodology proposed as StructuralComponents (Rolvink et al [6] and van de Weerd et al [7]) as a method to perform a digital verification process to fulfil the requirements related to structural design and engineering as part of a building design. In current design and engineering computing methodologies often only very limited design and engineering activities are digitised, such as the analysis and documentation (drawings). However, the conceptual justification that a structural designer makes in order to prove that a structure can withstand all scenarios with an appropriate low risk of exceeding its (structural) capacity rarely finds its way fully to paper or into computer programs. The research project on StructuralComponents works towards the goal to provide the computational framework to digitise this conceptual scenario-based justification in parametric and associative scenarios, analysis and documentation. This paper proposes to further structure this design computing methodology by integrating it with concepts from Systems Engineering (SE). INCOSE, The International Council on Systems Engineering [5], defines Systems Engineering as “Systems engineering is an interdisciplinary approach and means to enable the realisation of successful systems. It focuses on defining customer needs and required functionality early in the development cycle, documenting requirements, and then proceeding with design synthesis and system validation while considering the complete problem: operations, cost and schedule, performance, training and support, test, manufacturing, and disposal. SE considers both the business and the technical needs of all customers with the goal of providing a quality product that meets the user needs.” Systems Engineerings employs concepts like requirements and system breakdown structures to decompose design requirements and link them to system components that are intended fulfil these requirements. The process of ensuring that the system components and system behaviour fulfils the requirements is called the verification process. The proposal is for StructuralComponents to fulfil the function of a digital means to perform this verification during the design process. The authors propose to add a standardised Structural Requirements Breakdown Structure (SRBS) to the Requirements Breakdown Structure that fulfil the root requirement of a safe and functional structure. Additionally, the authors propose to add Calculation Breakdown Structure (CBS) to the methodology that contain the various calculations which prove that the structural elements in the System Breakdown Structure fulfil the requirements on the Structural Requirements Breakdown Structure. This further structuring of the design computing methodology provides new opportunities for automated and manual structured code checking.","conceptual design; design computing; engineering computing; structural design; systems engineering; StructuralComponents; parametric and associative design","en","conference paper","International Association for Shell and Spatial Structures (IASS)","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:88cc0d65-3cd3-4e1c-b425-14a43eeb49a5","http://resolver.tudelft.nl/uuid:88cc0d65-3cd3-4e1c-b425-14a43eeb49a5","EnergyFacade - Operational energy optimisation for conceptual facade design","Heidegger, V.; Coenders, J.L.; Rolvink, A.","","2014","This paper presents the results of the investigation into the possibilities for the implementation of a Building Performance Simulation design toolbox during the early stages of façade design, based on the sustainability-open framework [2]. The background and development of the EnergyFacade toolbox will be discussed which has been built on the principles of parametric and associative design [3] as a strategy for operational energy assessment and optimisation.","design and engineering computing; conceptual design; energy performance; façades; sustainability-open; BPS","en","conference paper","International Association for Shell and Spatial Structures (IASS)","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:1dc55ce5-18c3-4986-b668-f70d9b24aac0","http://resolver.tudelft.nl/uuid:1dc55ce5-18c3-4986-b668-f70d9b24aac0","A Conceptual Design and Analysis Method for Conventional and Unconventional Airplanes","Elmendorp, R.J.M.; Vos, R.; La Rocca, G.","","2014","A design method is presented that has been implemented in a software program to investigate the merits of conventional and unconventional transport airplanes. Design and analysis methods are implemented in a design tool capable of creating a conceptual design based on a set of toplevel requirements. In contrast to established design methods, emphasis is placed on designing unconventional as well as conventional airplane configurations. A parametric fuselage primitive and a parametric lifting-surface primitive have been defined. By combining various instances of these primitives, airplane geometries ranging from blended-wing-body configurations to threesurface configurations can quickly be generated. Analysis methods have been developed/refined such as to enable the (physics-based) disciplinary analysis of conventional and unconventional airplane concepts. Design rules have been implemented to automatically size the main airplane components. This paper describes the workings of the software tool, presents relevant validation studies and showcases a comparison study between five different airplane configurations.","airplane design; multidisciplinary design optimization; knowledge-based engineering","en","conference paper","International Council of Aeronautical Sciences","","","","","","","","Aerospace Engineering","Aerodynamics, Wind Energy & Propulsion","","","",""
"uuid:59f48430-b5c5-48b4-83fc-ba722de12820","http://resolver.tudelft.nl/uuid:59f48430-b5c5-48b4-83fc-ba722de12820","Refactoring Fat Interfaces Using a Genetic Algorithm","Romano, D.; Raemaekers, S.; Pinzger, M.","","2014","Recent studies have shown that the violation of the Interface Segregation Principle (ISP) is critical for maintaining and evolving software systems. Fat interfaces (i.e., interfaces violating the ISP) change more frequently and degrade the quality of the components coupled to them. According to the ISP the interfaces’ design should force no client to depend on methods it does not invoke. Fat interfaces should be split into smaller interfaces exposing only the methods invoked by groups of clients. However, applying the ISP is a challenging task when fat interfaces are invoked differently by many clients. In this paper, we formulate the problem of applying the ISP as a multi-objective clustering problem and we propose a genetic algorithm to solve it. We evaluate the capability of the proposed genetic algorithm with 42,318 public Java APIs whose clients’ usage has been mined from the Maven repository. The results of this study show that the genetic algorithm outperforms other search based approaches (i.e., random and simulated annealing approaches) in splitting the APIs according to the ISP","Interface Segregation Principle; APIs; refactoring; search-based software engineering; genetic algorithms","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:011b1333-c89d-426e-8bfb-77577deea2a3","http://resolver.tudelft.nl/uuid:011b1333-c89d-426e-8bfb-77577deea2a3","Supporting Collaboration in Global Software Engineering","Dullemond, K.","Van Solingen, D.M. (promotor); Van Deursen, A. (promotor)","2014","More and more, software engineering projects are no longer carried out in a single office building, but instead in multiple dislocated office buildings or even from home. When the development process is distributed between several geographically dispersed locations this is known as Global Software Engineering or GSE. The team members working on the project are separated geographically, temporally and/or socio-culturally and the existence of these three distances makes coordination, communication and cooperation much harder. This brings us to the main goal of this dissertation which is: “To understand which technological support is needed for Global Software Engineering teams to be able to collaborate effectively”. More specifically, we investigated what types of information that are readily available in the co-located setting but not in a distributed setting, are potentially most valuable and how these can be made available to GSE teams as well. To reach this goal we have divided the dissertation in two parts. In the first part, we zoomed in on one specific shortcoming of the distributed setting: it is impossible to overhear conversations of non-collocated colleagues. We investigated the problem itself (RQ1) but also what general consequences introducing such a solution has in a distributed setting (RQ2). Subsequently, keeping what we have learned in the back of our minds, we zoomed out and investigated both the information needs of distributed software engineers (RQ3) and how to leverage the main contributions of this dissertation in practice (RQ4). The main conclusion of this dissertation is: (i) that in order to truly support distributed software engineering teams, support environments for them should consider collaboration a first-class citizen and (ii) the most important information needs of such teams are project related communication with the customer and the happiness of team members.","Awareness; Global Software Engineering; Collaboration; Distributed Teams; Support Environments; Overhearing Conversations; Information Needs; Mood-based Microblogging","en","doctoral thesis","","","","","","","","","Delft University of Technology","Electrical Engineering, Mathematics and Computer Science","","","",""
"uuid:e1841670-8365-4f4d-8fa1-d4d748fec81b","http://resolver.tudelft.nl/uuid:e1841670-8365-4f4d-8fa1-d4d748fec81b","Effect of Different Forcing Processes on the Longshore Sediment Transport at the Sand Motor, The Netherlands","Kaji, A.O.; Luijendijk, A.P.; van Thiel de Vries, J.S.M.; De Schipper, M.A.; Stive, M.J.F.","","2014","The Sand Motor is a pilot project of a ‘mega-nourishment’ built in the Dutch coast in 2011. In order to understand which conditions reshape those mega-nourishments the influence of different types of forcing on the longshore sediment transport along the Sand Motor has been assessed in this paper using a process-based model. The use of numerical simulations enables the independent assessment of the different processes influencing the sediment transport magnitudes and direction. A calibrated depth-averaged model of the Sand Motor was used in order to compute the sediment transport rates around the nourishment. Results show that the overall evolution of the Sand Motor is event-driven, as the combination of energetic wave conditions, strong winds and high storm surge levels can lead to high sediment transport rates and therefore intense erosion.","mega-nourishment; sediment transport; Sand Motor; sand engine; nourishment; ICCE 2014","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:92fb037f-6e77-4bf1-b538-fcb88377c6c4","http://resolver.tudelft.nl/uuid:92fb037f-6e77-4bf1-b538-fcb88377c6c4","Morphological Development of a Mega-Nourishment: First Observations at the Sand Engine","De Schipper, M.A.; De Vries, S.; Stive, M.J.F.; De Zeeuw, R.C.; Rutten, J.; Ruessink, B.G.; Aarninkhof, S.G.J.; Van Gelder-Maas, C.","","2014","Large (mega-scale) nourishments have been proposed as a promising alternative for traditional beach and shoreface nourishments, especially for locations with large structural erosion and sufficient sediment to dredge. This paper examines the initial bathymetric evolution of the Sand Engine, a mega-nourishment of 17 million m3 protruding almost 1 km seaward from its surrounding coast. Topographic surveys show that, despite the blunt initial shape of the nourishment, the sediment is reworked into a nearly symmetrical (bell curve like) shape in less than 1.5 years. The cross-shore extent decreased by 150 m in this period which is a reduction of 15 % of its original extent. Simultaneously, the alongshore size of the nourishment increased by 60 % as the sediment is redistributed to the adjacent coasts. This is also reflected in the large 1.6 million m3 loss of sediment on the peninsula. Almost 70 % of this volume is found to accrete in adjacent coastal sections. Although not all sediment loss from the peninsula could be relocated, the findings reveal that the Sand Engine mega nourishment is feeding its surrounding coast substantially.","feeder nourishment; mega nourishment; coastal safety; sediment transport; sand engine; Sand Motor; ICCE 2014","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4a76eb17-2733-4075-8098-0c502ff1ec12","http://resolver.tudelft.nl/uuid:4a76eb17-2733-4075-8098-0c502ff1ec12","Measured Gradients in Alongshore Sediment Transport Along the Dutch Coast","De Vries, S.; De Schipper, M.A.; Stive, M.J.F.","","2014","In this paper it is aimed to quantify bulk (surf-zone integrated) alongshore sediment transport using morphological data collected along the Dutch coast. The collected morphological data covers a domain of 18 km alongshore including the beach, the foreshore and the intertidal zone in the cross shore. The measurement domain contains the 20 million m 3 Sand Engine mega-nourishment. Detailed volume changes in cross shore profiles are calculated using the collected data. Based on the calculated volume changes in the cross shore profiles, gradients in alongshore transport can be derived. In the scope of this paper we have derived alongshore transport gradients considering three periods; 1) a period of one year; 2) a period of two months with mild wave conditions; 3) a period of four months with stormy weather. Changes in the derived gradients in sediment transport for the selected periods are significant depending on alongshore location and temporally varying forcing conditions. The potential of the data-set is only explored to a limited extent so far. Additional parameters to be analyzed in the future are coastline orientation and cross shore profile gradients.","alongshore sediment transport; sand engine; topographic measurement; Dutch coast; zandmotor; ICCE 2014","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:c8a11e06-6ea8-49e7-b18c-273ac4c8a137","http://resolver.tudelft.nl/uuid:c8a11e06-6ea8-49e7-b18c-273ac4c8a137","Structural safety: Study into critical factors in the design and construction process","Terwel, K.C.","Vambersky, J.N.J.A. (promotor); Vrouwenvelder, A.C.W.M. (promotor)","2014","Failure investigations show that 80-85% of the structural failures are caused by inadequacies in the design and construction process, related to human and organizational factors. This study showed that safety culture, allocation of responsibilities control, communication and collaboration and knowledge infrastructure need improvement in the current Dutch building industustry, to improve structural safety.","structural safety; quality management; risk management; forensic engineering; failure data","en","doctoral thesis","","","","","","","","2014-06-11","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:035d836d-19b1-4340-8042-160c58426e19","http://resolver.tudelft.nl/uuid:035d836d-19b1-4340-8042-160c58426e19","Geometric road runoff estimation from laser mobile mapping data","Wang, J. (TU Delft Optical and Laser Remote Sensing; Key Laboratory of quantitative Remote Sensing Information Technology; Chinese Academy of Sciences); González-Jorge, Higinio (University of Vigo); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing); Arias-Sánchez, Pedro (University of Vigo); Menenti, M. (TU Delft Optical and Laser Remote Sensing)","","2014","Mountain roads are the lifelines of remote areas but are often situated in complicated settings and prone to landslides, rock fall, avalanches and damages due to surface water runoff. The impact and likelihood of these types of hazards can be partly assessed by a detailed geometric analysis of the road environment. Field measurements in remote areas are expensive however. A possible solution is the use of a Laser Mobile Mapping System (LMMS) which, at high measuring rate, captures dense and accurate point clouds. This paper presents an automatic approach for the delineation of both the direct environment of a road and the road itself into local catchments starting from a LMMS point cloud. The results enable a user to assess where on the road most water from the surroundings will assemble, and how water will flow over the road after e.g. heavy snow melt or rainfall. To arrive at these results the following steps are performed. First outliers are removed and point cloud data is gridded at a uniform width. Local surface normal and gradient of each grid point are determined. The relative smoothness of the road is used as a criterion to identify the road's outlines. The local gradients are input for running the so-called D8 method, which simply exploits that surface water follows the direction of steepest descent. This method first enables the identification of sinks on the roadside, i.e. the locations where water flow accumulates and potentially enters the road. Moreover, the method divides the road's direct neighbourhood into catchments, each consisting of all grid cells having runoff to the same sink. In addition the method is used to analyse the surface flow over the road's surface. The new method is demonstrated on a piece of 153 meters long Galician mountain road as sampled by LMMS data.","Catchments; D8 algorithm; Mobile Laser Scanning; Point Cloud Data; Road Engineering; Road runoff","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:9ab636b1-9a28-4e93-bc7c-767aeb003cf5","http://resolver.tudelft.nl/uuid:9ab636b1-9a28-4e93-bc7c-767aeb003cf5","Effective use of 'underwater' planning tricks in complicated engineering networks?","Coenen, J.M.G.","","2014","Engineering-to-Order (ETO) processes in shipbuilding rely heavily on the short lead times of design and engineering information. Co-engineering parties are constantly confronted with the question whether or not to share immature, preliminary information: Working with preliminary information will certainly induce iterations and rework once the information has been consolidated. On the other hand, the time pressure is high and idly waiting for (more definite) information is also risky. The eventual goal of this research will be to obtain improved insights on the overall consequences of delay in engineering activities and to identify the missing information that is often causing such delays. But as an intermediate goal it is required to ‘rewrite’ daily engineering plans into a consistent set of activities, activity relations and resource requirements, opening the door to using more advanced planning algorithms for ETO planning. Therefore a set of patterns and rules was developed to automatically generate an underlying (more intricate) network of sub-activities. From this a consistent critical path planning - for instance suitable for Monte Carlo Simulation - can be generated. For a case ETO project this approach was tested in order to see whether this approach lead to - a valid schedule, - a better schedule (including stochastic information), - better progress reports. The conclusion is that the proposed method is capable of serving as a pre-processor for more advanced planning algorithms. This was demonstrated by executing Monte Carlo simulation to generate ‘stochastic’ schedules and revisions of schedules.","cyber-physical system; engineering-to-order; Monte-Carlo simulation; scheduling","en","conference paper","Delft University of Technology","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","","","",""
"uuid:ff865693-75c0-480a-a1fa-85e689851b4e","http://resolver.tudelft.nl/uuid:ff865693-75c0-480a-a1fa-85e689851b4e","Reference scheme for deriving aspects and criteria for forecasting functional performance and cost implications of cyber-physical products","Opiyo, E.Z.; Horvath, I.","","2014","","cyber-physical systems; feasibility analysis; forecasting; economic advantage; engineering design","en","conference paper","Delft University of Technology","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:25897a06-bb52-4adc-b015-a0b6c80ab3d2","http://resolver.tudelft.nl/uuid:25897a06-bb52-4adc-b015-a0b6c80ab3d2","Fabrication of metallic biomedical scaffolds with the space holder method: A review","Arifvianto, B.; Zhou, J.","","2014","Bone tissue engineering has been increasingly studied as an alternative approach to bone defect reconstruction. In this approach, new bone cells are stimulated to grow and heal the defect with the aid of a scaffold that serves as a medium for bone cell formation and growth. Scaffolds made of metallic materials have preferably been chosen for bone tissue engineering applications where load-bearing capacities are required, considering the superior mechanical properties possessed by this type of materials to those of polymeric and ceramic materials. The space holder method has been recognized as one of the viable methods for the fabrication of metallic biomedical scaffolds. In this method, temporary powder particles, namely space holder, are devised as a pore former for scaffolds. In general, the whole scaffold fabrication process with the space holder method can be divided into four main steps: (i) mixing of metal matrix powder and space-holding particles; (ii) compaction of granular materials; (iii) removal of space-holding particles; (iv) sintering of porous scaffold preform. In this review, detailed procedures in each of these steps are presented. Technical challenges encountered during scaffold fabrication with this specific method are addressed. In conclusion, strategies are yet to be developed to address problematic issues raised, such as powder segregation, pore inhomogeneity, distortion of pore sizes and shape, uncontrolled shrinkage and contamination.","tissue engineering; scaffold; space holder method; powder metallurgy; titanium","en","journal article","MDPI","","","","","","","","Mechanical, Maritime and Materials Engineering","Biomechanical Engineering","","","",""
"uuid:748de818-c728-438e-96d8-ac02351f3812","http://resolver.tudelft.nl/uuid:748de818-c728-438e-96d8-ac02351f3812","Methods for assessing basic particle properties and cytotoxicity of engineered nanoparticles","Kalantzi, O.I.; Biskos, G.","","2014","The increasing penetration of materials and products containing engineered nanoparticles (ENPs) to the market is posing many concerns regarding their environmental impacts. To assess these impacts, there is an urgent need of techniques for determining the health-related properties of ENPs and standards for assessing their toxicity. Although a wide number of systems for characterizing nanoparticles in different media (i.e., gases and liquids) is already commercially available, the development of protocols for determining the cytotoxicity of ENPs is still at an infant stage, drawing upon existing knowledge from general toxicology. In this regard, differences in the preparation of ENP-containing solutions for cytotoxicity testing, as well as in the steps involved in the tests can result in significant deviations and inconsistencies between studies. In an attempt to highlight the urgent need for assessing the environmental impacts of nanotechnology, this article provides a brief overview of the existing methods for determining health-related properties of ENPs and their cytotoxicity.","nanotechnology; engineered nanoparticles; cytotoxicity; human exposure","en","journal article","MDPI","","","","","","","","Applied Sciences","Chemical Engineering","","","",""
"uuid:f0e38597-a742-4e20-808d-93cc6726669b","http://resolver.tudelft.nl/uuid:f0e38597-a742-4e20-808d-93cc6726669b","Design and numerical investigation of swirl recovery vanes for the Fokker 29 propeller","Wang, Y.; Li, Q.; Eitelberg, G.; Veldhuis, L.L.M.; Kotsonis, M.","","2014","Swirl recovery vanes (SRVs) are a set of stationary vanes located downstream from a propeller, which may recover some of the residual swirl from the propeller, hoping for an improvement in both thrust and efficiency. The SRV concept design for a scaled version representing the Fokker 29 propeller is performed in this paper, which may give rise to a promotion in propulsive performance of this traditional propeller. Firstly the numerical strategy is validated from two aspects of global quantities and the local flow field of the propeller compared with experimental data, and then the exit flow together with the development of propeller wake is analyzed in detail. Three kinds of SRV are designed with multiple circular airfoils. The numerical results show that the swirl behind the propeller is recovered significantly with Model V3, which is characterized by the highest solidity along spanwise, for various working conditions, and the combination of rotor and vane produced 5.76% extra thrust at the design point. However, a lower efficiency is observed asking for a better vane design and the choice of a working point. The vane position is studied which shows that there is an optimum range for higher thrust and efficiency.","multiple circular airfoil; propellers; propulsion efficiency; swirl recovery vane; turboprop engine","en","journal article","Elsevier","","","","","","","","Aerospace Engineering","Aerodynamics, Wind Energy & Propulsion","","","",""
"uuid:f2baf1ce-a3c2-43b2-b628-a77056d1d132","http://resolver.tudelft.nl/uuid:f2baf1ce-a3c2-43b2-b628-a77056d1d132","Failure: Analysis of an Engineering Concept","Del Frate, L.","Kroes, P.A. (promotor); Vermaas, P.E. (promotor); Franssen, M.P.M. (promotor)","2014","This thesis is an attempt to clarify a concept we are all familiar with, engineers and non-engineers alike. It shows that, behind the first impression of familiarity, there is a wide range of intuitions about failure which are not easily reconciled. While the ensuing ambiguities and lack of clarity may be tolerated in ordinary circumstances, engineers strive for precision and efficiency. These qualities become even more relevant given that engineering activities are increasingly carried out by multidisciplinary and multicultural teams. The chapters included in this thesis illustrate that pursuing conceptual clarification may result in valuable contributions to the existing literature. The identification of tacit assumptions that, so far, have gone undetected can help bringing some degree of order and unity to discussions that have shown a tendency towards fragmentation along disciplinary boundaries. As a whole, these chapters constitute the preliminaries of a conceptual framework that, once supplemented with additional engineering and philosophical contributions, may embrace the multiple facets of failure; a rather complex tangle of phenomena which, despite engineers’ efforts to rein it in, is not going to disappear from the engineering agenda anytime soon.","Failure; Conceptual analysis; Root cause; Philosophy of technology; Failure analysis; Engineering ontology; Learning from failure","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","Values, Technology and Innovation","","","",""
"uuid:8d5017da-18e1-482c-a250-dcca8d90a443","http://resolver.tudelft.nl/uuid:8d5017da-18e1-482c-a250-dcca8d90a443","Ecological Approach to Pilot Situation Awareness","Van Dam, S.B.J.","Mulder, M. (promotor); Van Paassen, M.M. (promotor)","2014","Future air traffic concepts foresee that in unmanaged airspace, to reduce workload of air traffic controllers and the resulting constraints on capacity, the separation task will be delegated to the flight deck. Technology-driven pilot self-separation support systems have been developed that present explicit automated solutions to deal with conflicts. These systems do not offer a transparent window on the reasoning of the automation, making it difficult for pilots to judge the validity of the proposed automated solution, or come up with safe ‘good-enough’ alternatives. This thesis engaged to solve the fundamental problem of determining ‘what information’, and ‘what visual form’ would best promote pilot situation awareness (SA), to safely and effectively deal with traffic. Several prototypes for an airborne trajectory planning tool were designed and evaluated. A formative constraint-based design approach was adopted, Ecological Interface Design (EID), to create an ‘ecological’ airborne separation assistance system. The ecological approach gives priority to the worker’s environment, or ‘ecology’, focusing on how the environment imposes constraints on the worker. EID is hypothesized to improve operator SA and overall system safety when compared to normative, task-oriented, user-centered design approaches, especially in situations that were unanticipated by designers. From this thesis we conclude the following. First of all, this work has clearly shown that an ecological display, providing pilots a profound layer of information without any help of automation in terms of explicit advices, can be as safe and as effective as traditional displays that mainly present explicit automated advisories. Second, the design of ecological interfaces in domains where the abstract functions are less obvious, like the self-separation problem studied here, benefits from an incremental, evolutionary approach. Indeed, EID is not a recipe. Third, from the comparison with the more traditional design it became clear that although reducing the solution space dimension can have benefits in terms of reducing cognitive load, in the end it may lead to more cognitive load for operators to build a correct and complete mental model of the situation. Fourth, and related, although an appropriate ecologically-inspired interface can alleviate a pilot’s dependency on an explicit compelling advisory, adding dimensionality to the pilot control actions (e.g., involving more and more constraints) may render the ecological display to become too complex to be used without some sort of automated advisories. The ecological overlays developed here could be the ‘missing link’ to design a Joint Cognitive System (JCS). That is, the ecological overlays may be used to close the gap in the awareness of situations shared between automation and pilot, enabling pilots to better judge the fidelity of the proposed solution and, in case the automation fails, to come up with good-enough alternative resolutions. That is, traditional task-oriented displays and the ecological displays do not exclude each other’s use in one system. On the contrary, whereas task-oriented support may lower cognitive workload in simple standard situations through the availability of easy-to-use, automated instructions, the ecological decision support overlays show the ‘total situation’ to help the operator to become an expert and able to deal with unanticipated events. Key in this JCS design effort is to use automation as a tool to lower cognitive effort and improve decision making in such a way that it does not destroy the benefits of ecological properties of the design.","Aviation Safety; Ecological Interface Design; Automation; Separation Assistance; Human Factors; Situation Awareness; Cockpit Display; Conflict Situation; Human-Machine Interaction; Cognitive Systems Engineering; Constraint-based visualisation; Spatio-temporal; Trajectory Planning; Meaningful Physics","en","doctoral thesis","Delft University of Technology","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:f23b8aa7-7e2e-49a7-af11-0054f5ef3b28","http://resolver.tudelft.nl/uuid:f23b8aa7-7e2e-49a7-af11-0054f5ef3b28","Open Genetic Code: On open source in the life sciences","Deibel, E.","","2014","The introduction of open source in the life sciences is increasingly being suggested as an alternative to patenting. This is an alternative, however, that takes its shape at the intersection of the life sciences and informatics. Numerous examples can be identified wherein open source in the life sciences refers to access, sharing and collaboration as informatic practices. This includes open source as an experimental model and as a more sophisticated approach of genetic engineering. The first section discusses the greater flexibly in regard of patenting and the relationship to the introduction of open source in the life sciences. The main argument is that the ownership of knowledge in the life sciences should be reconsidered in the context of the centrality of DNA in informatic formats. This is illustrated by discussing a range of examples of open source models. The second part focuses on open source in synthetic biology as exemplary for the re-materialization of information into food, energy, medicine and so forth. The paper ends by raising the question whether another kind of alternative might be possible: one that looks at open source as a model for an alternative to the commodification of life that is understood as an attempt to comprehensively remove the restrictions from the usage of DNA in any of its formats.","open source; life sciences; informatics; synthetic biology; patents; genetic engineering; OA-Fund TU Delft","en","journal article","SpringerOpen","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:b7e1367c-cff1-4863-9a15-55bb3eb39134","http://resolver.tudelft.nl/uuid:b7e1367c-cff1-4863-9a15-55bb3eb39134","Flood modelling: Parameterisation and inflow uncertainty","Mukolwe, M.M.; Di Baldassarre, G.; Werner, M.; Solomatine, D.P.","","2014","This paper presents an analysis of uncertainty in hydraulic modelling of floods, focusing on the inaccuracy caused by inflow errors and parameter uncertainty. In particular, the study develops a method to propagate the uncertainty induced by, firstly, application of a stage–discharge rating curve and, secondly, parameterisation of a onedimensional hydraulic model by way of the power function and the conditioning of Manning’s roughness coefficients. The proposed methodology was applied to a 98 km reach of the River Po, Italy. Model performance was evaluated using two independent sets of observed water levels in the river reach within a generalised likelihood uncertainty estimation framework. The inflow uncertainty was found to have a greater contribution to the overall uncertainty of the 1D model than the roughness parameters. Independent parameter conditioning and validation, as well as the uncertainty analysis, showed satisfactory model performance. When conditioned on one flood event, the model adequately simulated flood levels and high water marks for another (independent) event, as the observations were within 90% confidence interval of the simulation ensemble.","floods; floodworks/hydraulics; hydrodynamics/river engineering","en","journal article","ICE Publishing","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:1acda476-f94d-41be-9a61-b79de2992917","http://resolver.tudelft.nl/uuid:1acda476-f94d-41be-9a61-b79de2992917","An Exploratory Study of the Pull-based Software Development Model","Gousios, G. (TU Delft Software Engineering); Pinzger, M. (University of Klagenfurt); van Deursen, A. (TU Delft Software Technology)","","2014","The advent of distributed version control systems has led to the development of a new paradigm for distributed software development; instead of pushing changes to a central repository, developers pull them from other repositories and merge them locally. Various code hosting sites, notably Github, have tapped on the opportunity to facilitate pull-based development by offering workflow support tools, such as code reviewing systems and integrated issue trackers. In this work, we explore how pull-based software development works, first on the GHTorrent corpus and then on a carefully selected sample of 291 projects. We find that the pull request model offers fast turnaround, increased opportunities for community engagement and decreased time to incorporate contributions. We show that a relatively small number of factors affect both the decision to merge a pull request and the time to process it. We also examine the reasons for pull request rejection and find that technical ones are only a small minority.","Pull-based development; pull request; distributed software development; emperical software engineering","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","Software Technology","Software Engineering","","",""
"uuid:6d4b5581-6091-48eb-8250-ad82f41e6ef4","http://resolver.tudelft.nl/uuid:6d4b5581-6091-48eb-8250-ad82f41e6ef4","Measured gradientsin alongshore sediment transport along the Dutch coast","de Vries, S. (TU Delft Coastal Engineering); de Schipper, M.A. (TU Delft Coastal Engineering); Stive, M.J.F. (TU Delft Coastal Engineering)","Lynett, P. (editor)","2014","In this paper it is aimed to quantify bulk (surf-zone integrated) alongshore sediment transport using morphological data collected along the Dutch coast. The collected morphological data covers a domain of 18 km alongshore including the beach, the foreshore and the intertidal zone in the cross shore. The measurement domain contains the 20 million m3 Sand Engine mega-nourishment. Detailed volume changes in cross shore profiles are calculated using the collected data. Based on the calculated volume changes in the cross shore profiles, gradients in alongshore transport can be derived. In the scope of this paper we have derived alongshore transport gradients considering three periods; 1) a period of one year; 2) a period of two months with mild wave conditions; 3) a period of four months with stormy weather. Changes in the derived gradients in sediment transport for the selected periods are significant depending on alongshore location and temporally varying forcing conditions. The potential of the data-set is only explored to a limited extent so far. Additional parameters to be analyzed in the future are coastline orientation and cross shore profile gradients.","Alongshore sediment transport; Sand Engine; Topographic measurements","en","conference paper","American Society of Civil Engineers (ASCE)","","","","","","","","","","Coastal Engineering","","",""
"uuid:90f56554-6ad1-4fff-a292-c977368cea63","http://resolver.tudelft.nl/uuid:90f56554-6ad1-4fff-a292-c977368cea63","Towards a top-K SPARQL query benchmark generator","Zahmatkesh, Shima (Politecnico di Milano); Della Valle, Emanuele (Politecnico di Milano); Dell'Aglio, Daniele (Politecnico di Milano); Bozzon, A. (TU Delft Web Information Systems)","","2014","The research on optimization of top-k SPARQL query would largely benefit from the establishment of a benchmark that allows comparing different approaches. For such a benchmark to be meaningful, at least two requirements should hold: 1) the benchmark should resemble reality as much as possible, and 2) it should stress the features of the topk SPARQL queries both from a syntactic and performance perspective. In this paper we propose Top-k DBPSB: an extension of the DBpedia SPARQL benchmark (DBPSB), a benchmark known to resemble reality, with the capabilities required to compare SPARQL engines on top-k queries.","SPARQL benchmank; SPARQL engines; Top-k query","en","journal article","","","","","","","","","","","Web Information Systems","","",""
"uuid:00654999-6ff3-4f9f-ae50-85e1564cbc26","http://resolver.tudelft.nl/uuid:00654999-6ff3-4f9f-ae50-85e1564cbc26","SimDelta global: Towards a standardised interactive model for water infrastructure development","Rijcken, T.; Christopher, D.K.","","2013","The research project ‘SimDelta’ builds on novel internet technology to support the development of the Rhine-Meuse delta water infrastructure. It has three goals: education, organisation of research and design studies, and stakeholder polling. A current question is how the SimDelta technology could be made transferable to systems outside Europe, such as in California, Shanghai, Thailand and Indonesia. Fundamentally, all water systems are similar. Technically they differ in scale, geometry, resolution and functional emphasis, but system boundaries can be standardised. It is essential that SimDelta graphically acknowledges different data quality levels, to allow for standardisation and piecemeal development. Political coordination of infrastructure improvements appears to be difficult everywhere. Since SimDelta aims to clarify connections between high and low scale levels, it is expected to benefit the development of any water system. However, strategically it is recommended to start with the California system, for reasons of scientific maturity and political openness.","water infrastructure palanning; interactive modeling; crowdsourcing; water management; hydraulic engineering; adaptive management","en","journal article","EUROGEO","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:a7c42e61-b071-41ac-83a5-7745fe98415e","http://resolver.tudelft.nl/uuid:a7c42e61-b071-41ac-83a5-7745fe98415e","Towards a weighted voting system for Q&A sites","Romano, D.; Pinzger, M.","","2013","Version: Accepted for publication in the Proceedings of the International Conference on Software Maintenance (ICSM), 2013, IEEE Computer Society. Doi: http://dx.doi.org/10.1109/ICSM.2013.49 Q&A sites have become popular to share and look for valuable knowledge. Users can easily and quickly access high quality answers to common questions. The main mechanism to label good answers is to count the votes per answer. This mechanism, however, does not consider whether other answers were present at the time when a vote is given. Consequently, good answers that were given later are likely to receive less votes than they would have received if given earlier. In this paper we present a Weighted Votes (WV) metric that gives different weights to the votes depending on how many answers were present when the vote is performed. The idea behind WV is to emphasize the answer that receives most of the votes when most of the answers were already posted. Mining the Stack Overflow data dump we show that the WV metric is able to highlight between 4.07% and 10.82% answers that differ from the most voted ones.","mining repositories; stack overflow; Q&A sites; software engineering; metrics; social media; social coding","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","2014-12-31","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:282c428a-be28-4eb0-a210-3d98aed2f4cf","http://resolver.tudelft.nl/uuid:282c428a-be28-4eb0-a210-3d98aed2f4cf","Modeling student success with students","Van den Bogaard, M.E.D.; Verbraeck, A.; De Graaff, E.","","2013","Engineering education is a fairly new field of research and student success is in many aspects unexplored territory. Yet, student success is among the most researched topics in higher education. Several agencies have stressed the importance of engineering student success, because they found that there is a shortage of engineers in Europe and it is important that schools of engineering and technology will train more engineers for the labour force [1]. Research has yielded a lot of insight on factors that are related to student success. However, this research has not led to any major changes in student retention, neither in engineering nor in non-engineering subjects [2]. Most studies into student success are based exclusively on statistical analysis, e.g. [3, 4, 5]. In this project we intend to develop a situated model for student success. We include input from students in our research and we use this to enhance our understanding of students and their success and as input for our analysis. This paper is part of this ongoing research effort. In this paper we report on one of the research activities where we collected data from students on their perceptions of factors that contribute to their success. We invited first year students from different engineering programmes to workshops where we asked them which factors influence their success and how these factors are related, in the students' perceptions. We compare the student models with models based on survey data collected in the same university and in the same cohort. The aim of this comparison is to find out if students’ models correlate with models based on data analysis.","student success; engineering education; mixed methods","en","conference paper","SEFI","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:4467a9c3-edee-4822-b420-1c4286b717d3","http://resolver.tudelft.nl/uuid:4467a9c3-edee-4822-b420-1c4286b717d3","The uses of norms","Singh, M.P.; Arrott, M.; Balke, T.; Chopra, A.; Christiaanse, R.M.J.; Cranefield, S.; Dignum, F.; Eynard, D.; Farcas, E.; Fornare, N.; Gandon, F.; Governatori, G.; Dam, H.K.; Hulstijn, J.; Krueger, I.; Lam, H.P.; Meisinger, M.; Noriega, P.; Tony, B.; Savarimuthu, R.; Tadanki, K.; Verhagen, H.; Villata, S.","","2013","This chapter presents a variety of applications of norms. These applications include governance in sociotechnical systems, data licensing and data collection, understanding software development teams, requirements engineering, assurance, natural resource allocation, wireless grids, autonomous vehicles, serious games, and virtual worlds.","norms; MAS; governance; requirements engineering","en","book chapter","Dagstuhl","","","","","","","","Technology, Policy and Management","Infrastructures, Systems and Services","","","",""
"uuid:d44876fe-45dd-44ae-8947-622613eb963c","http://resolver.tudelft.nl/uuid:d44876fe-45dd-44ae-8947-622613eb963c","Harnessing the potential of Knowledge Based Engineering in manufacturing design","Van den Berg, T.","Van Tooren, M.J.L. (promotor)","2013","An increase in productivity is required for the European aviation industry to remain competitive in a world with rising competition, shorter development timescales, more complex products and decreasing numbers of technically skilled personnel. Fokker Elmo, a Dutch aircraft electrical wiring harness manufacturer, is facing these challenges. At present, preparing a wiring harness for manufacturing is a repetitive, time-consuming and mostly manual, experience-based process. The research presented in this thesis aims at developing techniques to largely automate the generation of wiring harness manufacturing drawings, using Knowledge Based Engineering (KBE). A development approach is proposed as well as KBE building blocks. Three KBE applications are developed and tested that offer functionalities not present in general-purpose CAD systems. These applications can considerably reduce the amount of repetitive work, while ensuring compliance to physical constraints and manufacturing guidelines.","Knowledge Based Engineering; search; manufacturing; automation; wiring; formboard","en","doctoral thesis","","","","","","","","2013-12-18","Aerospace Engineering","Flight Performance and Propulsion","","","",""
"uuid:d0782f7d-0445-41a8-bc64-a177c117ec1a","http://resolver.tudelft.nl/uuid:d0782f7d-0445-41a8-bc64-a177c117ec1a","Reverse engineering of industrially relevant phenotypes in yeast: An integrated approach","Oud, B.","Pronk, J.T. (promotor)","2013","Reverse engineering is the study of discovering the structure, function and operation of a device or system with the express aim to reconstruct its key functionalities. This principle is applied to many disciplines, from military, through computer engineering, to health, but also in metabolic engineering. In this context, reverse metabolic engineering examines a particular functionality or phenotype of a cell or culture and subsequently aims to reconstruct it, with the aid of targeted genetic modification, in another cell or culture. Even with increasing knowledge on targeted metabolic engineering, microbial production platforms for fuels and chemicals are often obtained by non-targeted approaches, such as mutagenesis or evolutionary engineering. Reverse engineering of the interesting traits of these microbial platforms not only provides the potential to implement and combine them in other hosts, but also allows for the protection of the resulting intellectual property. The major challenge in reverse metabolic engineering is the elucidation of the molecular mechanisms underlying the phenotype of the strains of interest. In this thesis, various techniques were evaluated for their application in reverse metabolic engineering of a diverse range of industrially relevant phenotypes in the yeast Saccharomyces cerevisiae. Simultaneously, the different analytical methods that were used in these studies were evaluated for their individual and combined contributions.","reverse engeering; inverse metabolic engineering; evolutionary engineering; metabolic engineering; synthetic biology; biofuels; biochemicals","en","doctoral thesis","","","","","","","","2013-11-27","Applied Sciences","Biotechnology","","","",""
"uuid:66c177e8-9da2-407a-83b4-fa80789a676e","http://resolver.tudelft.nl/uuid:66c177e8-9da2-407a-83b4-fa80789a676e","A Method for Enterprise Ontology based Design of Enterprise Information Systems","De Jong, J.","Dietz, J.L.G. (promotor)","2013","A method for designing an Enterprise information system, which is based on an implementation independent model of the organization, has been developed. This model, also called an ontological model, consists of both implementation independent business processes and implementation independent information processes. An Enterprise information system (EIS) has to be understood as an implementation scenario of the ontological model. This study contains a specification framework that provides rules for taking into account during engineering the EIS.","enterprise engineering; enterprise information system; designing business software; DEMO; information system","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Information Science","","","",""
"uuid:31fdf63a-3dc8-407e-8a5c-8b3ffd938af0","http://resolver.tudelft.nl/uuid:31fdf63a-3dc8-407e-8a5c-8b3ffd938af0","Transport of Dicarboxylic Acids in Saccharomyces cerevisiae","Jamalzadeh, E.","Heijnen, J.J. (promotor); Van Gulik, W.M. (promotor)","2013","","Saccharomyces cerevisiae; Metabolic Engineering; Succinic Acid; Fumaric Acid; Transport; Low pH","en","doctoral thesis","","","","","","","","2013-11-19","Applied Sciences","Biotechnology","","","",""
"uuid:6f8f9802-f174-4be9-b51e-741315add1be","http://resolver.tudelft.nl/uuid:6f8f9802-f174-4be9-b51e-741315add1be","A designerly methodology for software development","Du Bois, E.","Horvath, I. (promotor)","2013","This PhD researches the domain of industrial design engineering starting from the strong technological evolutions and changing economic, social and ecological needs. Our current products are not only build from hardware components, but are a complex mix of hardware, software and services (in different proportions). This complexity is needed to be able to respond to our continuously evolving needs. In this PhD research, we focus on the software that is part of our products, because we do not only use Facebook and email on our mobile phone, but also our car and washing machine need software to operate. During the design of these software parts, it is complex to test and discuss the design with all stakeholders at different moments. Nevertheless these discussions enable to optimize the software before programming starts. This PhD research focusses on the development of a methodology to support designers in the development of interactive software, involving all stakeholders (different types of users, customers, suppliers, experts
). The methodology is based on the principles of hardware consumer product development and supports the designers in the critical early phases of the development process. During this process, the aim is to collect as many opinions, ideas and suggestions from all different stakeholders about the different prototypes. These prototypes (starting from an abstract prototype towards a testable) are used in each phase of the design process to discuss and co-develop the software in order to achieve products that qualitatively better fulfill the stakeholders needs.","software development; industrial design engineering; prototyping; stakeholder involvement; human-centered design; methodology; software; complex systems","en","doctoral thesis","VSSD","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:974d45fc-0aa1-4bbf-be83-bb63b3dc5f4b","http://resolver.tudelft.nl/uuid:974d45fc-0aa1-4bbf-be83-bb63b3dc5f4b","Genome duplication and mutations in ACE2 cause multicellular, fast-sedimenting phenotypes in evolved Saccharomyces cerevisiae","Oud, B.; Guadalupe-Medina, V.; Nijkamp, J.F.; De Ridder, D.; Pronk, J.T.; Van Maris, A.J.A.; Daran, J.G.","","2013","Laboratory evolution of the yeast Saccharomyces cerevisiae in bioreactor batch cultures yielded variants that grow as multicellular, fast-sedimenting clusters. Knowledge of the molecular basis of this phenomenon may contribute to the understanding of natural evolution of multicellularity and to manipulating cell sedimentation in laboratory and industrial applications of S. cerevisiae. Multicellular, fast-sedimenting lineages obtained from a haploid S. cerevisiae strain in two independent evolution experiments were analyzed by whole genome resequencing. The two evolved cell lines showed different frameshift mutations in a stretch of eight adenosines in ACE2, which encodes a transcriptional regulator involved in cell cycle control and motherdaughter cell separation. Introduction of the two ace2 mutant alleles into the haploid parental strain led to slow-sedimenting cell clusters that consisted of just a few cells, thus representing only a partial reconstruction of the evolved phenotype. In addition to single-nucleotide mutations, a whole-genome duplication event had occurred in both evolved multicellular strains. Construction of a diploid reference strain with two mutant ace2 alleles led to complete reconstruction of the multicellular-fast sedimenting phenotype. This study shows that whole-genome duplication and a frameshift mutation in ACE2 are sufficient to generate a fast-sedimenting, multicellular phenotype in S. cerevisiae. The nature of the ace2 mutations and their occurrence in two independent evolution experiments encompassing fewer than 500 generations of selective growth suggest that switching between unicellular and multicellular phenotypes may be relevant for competitiveness of S. cerevisiae in natural environments.","whole genome sequencing; reverse engineering","en","journal article","National Academy of Sciences","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:a3795084-4b85-40e9-9ba1-b545408954a2","http://resolver.tudelft.nl/uuid:a3795084-4b85-40e9-9ba1-b545408954a2","Novel strategies for engineering redox metabolism in Saccharomyces cerevisiae","Guadalupe Medina, V.G.","Pronk, J.T. (promotor); Van Maris, A.J.A. (promotor)","2013","In its search to decrease the environmental impact of the production of materials and food, and for other socio-economic reasons, mankind has recently taken the first steps into a paradigm shift from a petrochemical-based society to a new, sustainable and to a significant extent bio-based society. In this new scenario, biomass derived from agriculture and forestry industry and/or its residues are used for the generation of chemicals and materials that are currently derived from oil. To produce these chemicals, microorganisms and/or enzyme-catalyzed reactions can be used to convert the carbohydrates present in the biomass into a wide variety of products. Industrial biotechnology studies these conversion processes and aims to improve them. Nowadays, the single largest process in industrial biotechnology, in terms of product volume, is the production of ethanol from sugars using baker’s yeast (Saccharomyces cerevisiae). The study of this model organism in terms of physiology, metabolism and genetics has contributed to significant improvements in industrial biotechnology. However, to compete with the efficiency and economics of petrochemical industry, also for products other than ethanol, further major breakthroughs are necessary. To achieve these advances, a knowledge-based redesign, followed by implementation of genetic changes via state-of-the-art molecular biology tools is used to improve cellular activities of microbial cell factories. This discipline in applied science is called Metabolic Engineering. An important constraint in the design of metabolic engineering strategies is the balancing of reactions in metabolism that involve the transfer of electrons by the redox cofactor couples NADH/NAD+ and NADPH/NADP+. For instance, redox cofactor balancing plays a central role in the formation of glycerol as the major by-product of alcoholic fermentation by bakers’ yeast. Under aerobic conditions, oxygen is used as the final electron acceptor. However, under the anaerobic conditions that are required for cost effective production of ethanol, the yeast S. cerevisiae produces glycerol to reoxidize the “excess”-NADH derived from biosynthetic reactions. This PhD thesis aimed to explore new strategies to increase the flexibility of the (anaerobic) redox metabolism of S. cerevisiae for the production of fuels and chemicals. After a general introduction to industrial biotechnology and S. cerevisiae, Chapter 1 describes the concept of metabolic engineering and how it has been applied in the past to reduce the formation of glycerol formation in alcoholic fermentation. The ability of yeast cells to use glycerol as a redox sink can be eliminated by the double deletion of the genes encoding for glycerol-3-phosphate dehydrogenase (GPD1 and GPD2 in S. cerevisiae). In order to grow anaerobically, such mutants depend on the availability of an external electron acceptor, such as for instance externally added acetoin. However, addition of such a compound is too expensive to use on industrial scale. Of course, this is not a problem when the external electron acceptor is already present in the industrial feedstock. Acetic acid is present in small quantities in first generation feedstocks for ethanol production and in larger amounts as product from hydrolysis processes in lignocellulosic biomass (second generation feedstocks). Since, acetic acid is more oxidized than ethanol, its NADH-dependent reduction to ethanol could theoretically obviate the need for glycerol production in anaerobic cultures of S. cerevisiae. In practice, this does not occur because acetic acid is almost fully dissociated at the near-neutral pH inside yeast cells. Other microorganisms can use acetic acid as electron acceptor. These microorganisms use a linear pathway that first activates acetic acid to acetyl-CoA in a reaction that costs two ATP equivalents. In two subsequent reactions coupled to NADH oxidation, acetyl-CoA is first reduced to acetaldehyde, which is then reduced to ethanol. Only the reaction that reduces acetyl-CoA towards acetaldehyde, catalyzed by an (acetylating) acetaldehyde dehydrogenase, is not naturally present in S. cerevisiae. In Chapter 2, the replacement of glycerol formation as redox sink by acetic acid as external electron acceptor was studied in anaerobic cultures of a gpd1? gpd2? S. cerevisiae expressing the Escherichia coli mhpF gene encoding an (acetylating) acetaldehyde dehydrogenase. Growth of the constructed strain (gpd1? gpd2? mhpF) at a maximum specific growth rate of 0.14 h-1 was dependent on the presence of acetic acid. Under these conditions, the strain did not produce glycerol and showed a 13% higher ethanol yield on glucose than the isogenic reference strain (GPD1 GPD2). These results are a proof of concept for this metabolic engineering strategy, where glycerol formation was replaced by the removal of, otherwise inhibitory, acetic acid from lignocellulosic hydrolysates, leading to a significant increase in ethanol yield on glucose. Besides its role in redox-cofactor balancing, glycerol is also the main compatible solute of S. cerevisiae, accumulating inside yeast cells when they face high extracellular osmotic pressure. This type of stress is especially important in first generation alcoholic fermentation, where a high initial sugar concentration is present at the start of the production process. In Chapter 3, the tolerance to high osmotic pressure of a strain lacking functional glycerol-3-phosphate dehydrogenases (Gpd-) and able to use acetate as electron acceptor was studied. Based on these findings, evolutionary engineering for anaerobic growth at high sugar concentrations (1 M glucose) was used to obtain an osmotolerant Gpd- S. cerevisiae strain expressing an (acetylating) acetaldehyde dehydrogenase. After the desired phenotype was obtained, single colonies were isolated and characterized under relevant conditions. An isolated evolved Gpd- strain grew anaerobically at 1 M glucose at a maximum specific growth rate of 0.12 h-1 in the presence of acetic acid (2 g l-1). Surprisingly, formation of glycerol was observed again towards the end of the fermentation, albeit at much lower concentrations than in the Gpd+ reference strain under identical conditions. Moreover, the evolved strain exhibited an apparent higher ethanol yield on glucose than the reference strain, reaching a value of 1.84 mol mol-1 (92% of the theoretical ethanol yield on glucose), when cultured in the presence of 3 g l-1 of acetic acid and 1 M glucose. Genetic analysis of the evolved strain revealed that this evolved phenotype was the consequence of one dominant chromosomal mutation, and one mutation in the plasmid-borne mhpF gene for anaerobic growth. In industrial biotechnology, the use of evolutionary engineering coupled to reverse metabolic engineering is a powerful tool in the development of strains with desired phenotypes and in the transfer of these characteristics to different strains. However, during laboratory or industrial evolution, also undesired phenotypes are observed, which are equally important to comprehend: only by understanding their molecular basis, such phenotypes can be removed from production strains. Cell flocculation and/or aggregation were frequently observed during laboratory evolution in sequential batch cultures under a wide variety of selective culture conditions. Although flocculation can be a desired phenotype in beer brewing, where it may facilitate separation of the yeast, it is not desirable during evolutionary engineering, where it diverts the selective pressure away from the target of interest and furthermore complicates the generation of single cell lines. This phenomenon, which was also observed in some of the evolutionary engineering lines with Gpd- S. cerevisiae strains that were performed in the context of this thesis, was further studied in Chapter 4 with a strain obtained from laboratory evolution for faster consumption of glucose-galactose mixtures. Reverse metabolic engineering of ‘multicellular’ strains of S. cerevisiae obtained from this study revealed that genome duplication and deregulation of the cell cycle were key elements in the development of a multicellular/agglomeration phenotype. Whole genome sequencing of two single colony isolates from independent laboratory evolutions showed that multicellular phenotype resulted from different point mutations in ACE2 gene, a key transcriptional regulator in the separation between bud and mother cell in yeast. Moreover, both final evolved strains became diploids, whereas the original parental strain was haploid. The multicellular phenotype was reverted by introduction of a functional copy of the original ACE2 allele in the evolved strains. Introduction of the mutant allele and doubling the genome size by mating in the parent strain led to the same multicellular, fast-sedimenting phenotype that was observed in the evolved strains. These results do not only shed light on the mutations that underlie the evolution of multicellular yeast strains, but can also be applied to induce or eliminate cell aggregation in industrial strains. Major breakthroughs in industrial biotechnology benefit from rapidly developing techniques in synthetic biology. These advantages allow scientists to use bolder and more creative metabolic engineering strategies. An unexplored metabolic engineering strategy in redox metabolism is the use of carbon dioxide as electron acceptor via enzymes from autotrophic microorganisms. Carbon dioxide is a by-product of yeast fermentation and therefore abundantly present in industrial fermentation processes. The Calvin cycle, present in different autotrophic organisms, uses ATP and NADPH for carbon dioxide fixation and provides metabolic building blocks required in biosynthesis. Phosphoribulokinase and ribulose-1,5-bisphosphate carboxylase/oxidase (Rubisco) are the two key enzymes of the Calvin cycle and have been involved in the fixation of the majority of the organic carbon available in nature. Using state-of-the-art synthetic biology techniques, we functionally expressed both enzymes in a S. cerevisiae strain and studied its physiology in anaerobic carbon-limited chemostat cultures at a dilution rate of 0.05 h-1 (Chapter 5). Functional expression of a single-subunit Rubisco from the chemolithoautotrophic bacterium Thiobacillus denitrificans required the co-expression of chaperones proteins GroEL and GroES from E. coli, and resulted in the first functional expression of Rubisco in a heterotrophic eukaryotic microorganism. Anaerobic chemostat cultures sparged with pure nitrogen gas showed a 68% lower glycerol yield on sugars, and 11% and 12% higher ethanol and biomass yields on sugars, respectively, than an isogenic reference strain. Increasing the concentration of dissolved carbon dioxide by purging the fermenters with a gas mixture of 10% v/v CO2 and 90% v/v nitrogen resulted in a further decrease of the glycerol yield on sugars to less than 10% of that observed in the reference strain. To study the performance of the engineered strain using a fermentation setup more relevant to industrial application, anaerobic batch cultures were run on 20 g l-1 galactose in laboratory fermenters sparged with a 10%-90 % mixture of CO2 and nitrogen. Under these conditions, the constructed strain showed no differences in growth kinetics when compared to its isogenic reference, while its glycerol yield on galactose decreased by 60% and its ethanol yield on galactose increased by 8% relative to the reference strain. This strategy not only demonstrates the potential of using carbon dioxide as electron acceptor in the metabolic engineering of yeasts and other microorganisms, but also illustrates how co-expression of chaperone proteins can aid the functional expression of bacterial proteins in yeast cytosol. To conclude, this thesis presents two novel metabolic engineering strategies (Chapter 2 & 5) that increased the flexibility of redox metabolism in anaerobic fermentation by implementing novel redox sinks in baker’s yeast. Both strategies have high potential to substantially contribute to optimizing product formation by S. cerevisiae in anaerobic industrial biotechnological production processes. In such processes even a small increase in product yield on substrate, given the large volumes of production, can result in large economic benefits without the introduction of new process steps. Even though novel strategies can show high potential for industrial application, an integrative view on process optimization should also consider potential negative effects on strain robustness. Evolutionary engineering (Chapter 3) and reverse metabolic engineering (Chapter 4) of desired and undesired phenotypes, provide additional powerful tools in the implementation of metabolic engineering strategies. The chapters of this thesis represent small but significant steps in the vigorous research needed to enable wide-spread, economically viable and sustainable production of transport fuels and chemicals in a bio-based society.","Saccharomyces cerevisiae; metabolic engineering; redox metabolism","en","doctoral thesis","","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:534c0a47-83a5-4f18-bab6-f1cbd2794cc2","http://resolver.tudelft.nl/uuid:534c0a47-83a5-4f18-bab6-f1cbd2794cc2","One-step assembly and targeted integration of multigene constructs assisted by the I-SceI meganuclease in Saccharomyces cerevisiae","Kuijpers, N.G.A.; Chroumpi, S.; Vos, T.; Solis-Escalante, D.; Bosman, D.; Pronk, J.T.; Daran, J.G.; Daran-Lapujade, P.A.S.","","2013","In vivo assembly of overlapping fragments by homologous recombination in Saccharomyces cerevisiae is a powerful method to engineer large DNA constructs. Whereas most in vivo assembly methods reported to date result in circular vectors, stable integrated constructs are often preferred for metabolic engineering as they are required for large-scale industrial application. The present study explores the potential of combining in vivo assembly of large, multigene expression constructs with their targeted chromosomal integration in S. cerevisiae. Combined assembly and targeted integration of a ten-fragment 22-kb construct to a single chromosomal locus was successfully achieved in a single transformation process, but with low efficiency (5% of the analyzed transformants contained the correctly assembled construct). The meganuclease I-SceI was therefore used to introduce a double-strand break at the targeted chromosomal locus, thus to facilitate integration of the assembled construct. I-SceI-assisted integration dramatically increased the efficiency of assembly and integration of the same construct to 95%. This study paves the way for the fast, efficient, and stable integration of large DNA constructs in S. cerevisiae chromosomes.","synthetic biology; in vivo assembly; homologous recombination; pathway engineering","en","journal article","Wiley","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:4b926100-20fd-4b9a-bd6d-5039afb19cfa","http://resolver.tudelft.nl/uuid:4b926100-20fd-4b9a-bd6d-5039afb19cfa","Why Didn't They Ask the Supplier? The Utilization of Supplier Information and Knowledge in the Fuzzy Front End of New Product Development","Kopecká, J.A.","Santema, S.C. (promotor); Hultink, H.J. (promotor)","2013","In today’s world of multi-component and multi-technology products, firms are obliged to seek knowledge for new product development (NPD) from external sources. Supplier firms are one such external source. The thesis aims to contribute to the development of a theory on supplier involvement in new product development (NPD) by advancing understanding of the motives and conditions for the utilization of supplier information and knowledge in the fuzzy front end (FFE) of NPD. The term ‘fuzzy front end’ (FFE) refers to the activities that the firm undertakes prior to a NPD project. The FFE ends when the NPD project is launched, or rejected. The FFE of NPD is information intensive: it requires seeking, accessing and selecting different types of information from both internal and external sources. Previous research focused mostly on the external source of consumers and how ideas from consumers can lead to the generation of new product concepts. By comparison, the suppliers’ contribution to the FFE of NPD has received less attention. The thesis examines the exchange and utilization of supplier information and knowledge at the micro-social level of the firm between the individuals who work in the FFE of NPD. Three functional areas have been selected for the study, namely: (Design) Engineering and Purchasing of the customer firm and Sales Engineering of the supplier firm.","supplier information & knowledge; new product devlopment; industrial design; sales engineer; purchaser; design engineer; fuzzy front end; knowledge transfer; social ties; multiple case study","en","doctoral thesis","","","","","","","","2013-09-27","Industrial Design Engineering","Product Innovation Management","","","",""
"uuid:452e804a-e35e-4a1a-98ec-04ee1117b918","http://resolver.tudelft.nl/uuid:452e804a-e35e-4a1a-98ec-04ee1117b918","Open source engineering and sustainability tools for the built environment","Coenders, J.L.","","2013","This paper presents two novel open source software developments for design and engineering in the built environment. The first development, called “sustainability-open” [1], aims on providing open source design, analysis and assessment software source code for (environmental) performance of buildings, structures and infrastructure. The aim of this project is to take away barriers that might exist to design and engineer buildings, structures and infrastructure in a sustainable manner and based on quantitative measures or metrics of (environmental) performance for a variety of design aspects. The second development, called “engineering-open” [2], aims on providing open source software source code for design, calculation, form finding, analysis and optimisation of structures. Both developments aim to take away restrictions that might exist for science and practice caused by the unavailability of open and insightful software source code to inspire further research, development and innovation in the architecture, engineering and construction industry for new software approaches and tools.","digital design; design tools; engineering; sustainability; open source software; parametric software; BIM; finite element method; form finding; optimisation","en","conference paper","Wroclaw University of Technology","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:3013a7d7-e30c-412f-b98b-9d0e14e6292a","http://resolver.tudelft.nl/uuid:3013a7d7-e30c-412f-b98b-9d0e14e6292a","Attaining Performance with Building Information Modelling","Papadonikolaki, E.; Koutamanis, A.; Wamelink, J.W.F.","","2013","The paper presents the findings of a systematic literature review of approximately 200 scientific sources. It is designed with the aim to identify the current benefits and factors of high performance in Architecture, Engineering, Construction (AEC) since the introduction of Building Information Modelling (BIM). We formed and confirmed two main propositions associating the performance of the AEC to the use of BIM. The mapping of the current impact and benefits of BIM showed that the role of the managers, suppliers, owners and authorities is underestimated, as well as the initiation and use stage of project development. At the same time, the performance in the AEC industry can be improved by an array of possibilities where IT research and policy-making authorities contribute from establishing new collaboration protocols until improving existing or creating new BIM tools.","Building Information Modelling (BIM); Architecture, Engineering and Construction (AEC); supply chain management; life-cycle phases; stakeholders","en","conference paper","","","","","","","","","","","","","",""
"uuid:ba02fead-0ce1-4beb-855f-11df69ee0ba4","http://resolver.tudelft.nl/uuid:ba02fead-0ce1-4beb-855f-11df69ee0ba4","Attaining Performance with Building Information Modelling: A systematic literature review of product and process modelling in AEC","Papadonikolaki, E.; Koutamanis, A.; Wamelink, J.W.F.","","2013","The paper presents the findings of a systematic literature review of approximately 200 scientific sources. It is designed with the aim to identify the current benefits and factors of high performance in Architecture, Engineering, Construction (AEC) since the introduction of Building Information Modelling (BIM). We formed and confirmed two main propositions associating the performance of the AEC to the use of BIM. The mapping of the current impact and benefits of BIM showed that the role of the managers, suppliers, owners and authorities is underestimated, as well as the initiation and use stage of project development. At the same time, the performance in the AEC industry can be improved by an array of possibilities where IT research and policy-making authorities contribute – from establishing new collaboration protocols until improving existing or creating new BIM tools.","Building Information Modelling (BIM); Architecture, Engineering and Construction (AEC); supply chain management; life-cycle phases; stakeholders","en","conference paper","eCAADe (Education and research in Computer Aided Architectural Design in Europe)","","","","","","","","Architecture and The Built Environment","Real Estate and Housing","","","",""
"uuid:a7673088-dc1c-40b9-879b-9c0d7ae0b65e","http://resolver.tudelft.nl/uuid:a7673088-dc1c-40b9-879b-9c0d7ae0b65e","Automatic estimation of excavation volume from laser mobile mapping data for mountain road widening","Wang, J.; González-Jorge, H.; Lindenbergh, R.; Arias-Sánchez, P.; Menenti, M.","","2013","Roads play an indispensable role as part of the infrastructure of society. In recent years, society has witnessed the rapid development of laser mobile mapping systems (LMMS) which, at high measurement rates, acquire dense and accurate point cloud data. This paper presents a way to automatically estimate the required excavation volume when widening a road from point cloud data acquired by an LMMS. Firstly, the input point cloud is down-sampled to a uniform grid and outliers are removed. For each of the resulting grid points, both on and off the road, the local surface normal and 2D slope are estimated. Normals and slopes are consecutively used to separate road from off-road points which enables the estimation of the road centerline and road boundaries. In the final step, the left and right side of the road points are sliced in 1-m slices up to a distance of 4 m, perpendicular to the roadside. Determining and summing each sliced volume enables the estimation of the required excavation for a widening of the road on the left or on the right side. The procedure, including a quality analysis, is demonstrated on a stretch of a mountain road that is approximately 132 m long as sampled by a Lynx LMMS. The results in this particular case show that the required excavation volume on the left side is 8% more than that on the right side. In addition, the error in the results is assessed in two ways. First, by adding up estimated local errors, and second, by comparing results from two different datasets sampling the same piece of road both acquired by the Lynx LMMS. Results of both approaches indicate that the error in the estimated volume is below 4%. The proposed method is relatively easy to implement and runs smoothly on a desktop PC. The whole workflow of the LMMS data acquisition and subsequent volume computation can be completed in one or two days and provides road engineers with much more detail than traditional single-point surveying methods such as Total Station or GPS profiling. A drawback is that an LMMS system can only sample what is within the view of the system from the road.","mobile laser scanning; road engineering; 2D slope; volume estimation","en","journal article","MDPI","","","","","","","","Civil Engineering and Geosciences","Geoscience and Remote Sensing","","","",""
"uuid:96c65674-06d4-410c-87c2-b981af95211e","http://resolver.tudelft.nl/uuid:96c65674-06d4-410c-87c2-b981af95211e","Airborne Conflict Resolution in Three Dimensions","Ellerbroek, J.","Mulder, M. (promotor)","2013","The advent of automation in the cockpit has greatly affected the nature of the tasks on the flight deck, as well as requirements on the flight crew. Although the introduction of automation in aircraft undeniably improved performance and safety, it also increased complexity in the cockpit. In addition to knowledge of basic flight information, pilots are nowadays also required to keep track of how their automated systems work. This requires a coordination of tasks between automation and human actors, and a transparency of automation that can currently not always be guaranteed. The focus of this thesis is on the concept of airborne separation, which is proposed as part of both European and American plans for the future air-traffic management system. Such a system of airborne separation implies either partial or full delegation of separation responsibility from the controller to the aircrew. This should reduce workload for the controller on the ground, and consequently increase airspace capacity, but will also lead to a profound change on the flight deck. These plans will, in order to be realized, have substantial consequences for the degree of automation, both on the ground and in the cockpit. In this thesis it is argued that capturing the inherent work domain information in a functional representation should be the basis for automating the task of airborne separation. To accomplish this, a constraint-based approach, inspired by Ecological Interface Design (EID), was employed, to provide the basis for a transparent interface to automation. This method aims to make the structure of the work domain salient, and in addition to providing a basis for automation design, should yield an interface that facilitates transparency of automation, and should support operators in constructing situation awareness. Results from experiments presented in this thesis show that, regardless of the limited level of training that the participants received, they are able to use the interface concepts to find efficient resolutions. Because these kinds of displays make several complex relationships directly perceivable, they relieve pilots from cognitive work. This transforms what would otherwise be a task that requires knowledge-based problem solving, into a simple task of perception and observation, where pilots can apply basic skills and predefined rules to safely and efficiently resolve a conflict. This allows pilots to perform well, even with a limited amount of training.","Ecological Interface Design; Cognitive Systems Engineering; Human-Centered Automation; Flight Displays; Situation Awareness","en","doctoral thesis","","","","","","","","","Aerospace Engineering","Control and Simulation","","","",""
"uuid:c6e5f05f-fb0f-4c43-84ff-9dcbfbfe52e3","http://resolver.tudelft.nl/uuid:c6e5f05f-fb0f-4c43-84ff-9dcbfbfe52e3","The sand engine: A solution for the Dutch Delta in the 21st century?","Stive, M.J.F.; De Schipper, M.A.; Luijendijk, A.P.; Ranasinghe, R.W.M.R.J.B.; Aarninkhof, S.","","2013","The Netherlands’ strategy to combat coastal erosion since 1990 has been through nourishment, initially as beach nourishments but more and more as shoreface nourishments. In the light of sea level rise projections the yearly nourishment magnitudes continue to increase. In view of this an innovative soft engineering intervention, comprising an unprecedented 21 Mm3 sand nourishment known as the Sand Engine, has recently been implemented in the Netherlands. The Sand Engine nourishment is a pilot project to test the effectiveness and efficiency of a local mega-nourishment as a measure to account for the anticipated increased coastal recession in this century. The proposed concept, a single mega-nourishment, once every 20 years, is expected to be more efficient and effective in the long term than traditional beach and shoreface nourishments, presently being used at the Dutch coast with typically a three to five year interval. While the judgement is still out on this globally unique intervention, if proven successful, it may well become a generic solution for combating sea level rise driven coastal recession on open and vulnerable coasts.","nourishment; coastal erosion; sea level rise; storm erosion; shoreface processes; flooding; sand engine","en","conference paper","IAHR","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:c3b977ac-dbf1-4c62-8ceb-23212ff0dcc0","http://resolver.tudelft.nl/uuid:c3b977ac-dbf1-4c62-8ceb-23212ff0dcc0","Towards fermentation of galacturonic acid-containing feedstocks with Saccharomyces cerevisiae","Huisjes, E.H.","Pronk, J.T. (promotor)","2013","The ambition to reduce our current dependence on fossil transportation fuels has driven renewed interest in bioethanol. Pectin-rich feedstocks like sugar beet pulp and citrus peel, which are currently sold as cattle feed, are promising raw materials for the production of bioethanol. This thesis explores the challenges related to the fermentation of pectin-rich hydrolysates with Saccharomyces cerevisiae. Galacturonic acid is a major constituent of pectin-rich hydrolysates. Achieving efficient conversion of this compound is desired. This requires introduction of a heterologous pathway for galacturonate metabolism. In this project, we functionally expressed uronate isomerase and tagaturonate dehydrogenase, the first two enzymes of a bacterial catabolic pathway. Introduction of the entire 5-enzyme catabolic route did not result in a S. cerevisiae strain capable of galacturonic acid fermentation. Galacturonic acid will therefore remain present in the fermentation medium. It was shown that the presence of galacturonic acid negatively affects fermentation characteristics in aerobic chemostat cultivations. In addition, it was demonstrated that, especially at low pH, galacturonic acid has a drastic impact on cellular viability and galactose, arabinose and xylose consumption. As long as galacturonic acid is not consumed by S. cerevisiae, these inhibitory effects of galacturonic acid will remain a key issue in the yeast-based production of bioethanol and other products from pectin-rich feedstocks.","Saccharomyces cerevisiae; yeast; biotechnology; metabolic engineering; bioethanol; galacturonic acid","en","doctoral thesis","","","","","","","","2013-09-08","Applied Sciences","Department of Biotechnology","","","",""
"uuid:41139f9b-5e86-461b-bf5f-33fc7a40b1d3","http://resolver.tudelft.nl/uuid:41139f9b-5e86-461b-bf5f-33fc7a40b1d3","Carbon dioxide fixation by Calvin-Cycle enzymes improves ethanol yield in yeast","Guadalupe-Medina, V.; Wisselink, H.W.; Luttik, M.A.H.; De Hulster, E.; Daran, J.M.; Pronk, J.T.; Van Maris, A.J.A.","","2013","Background Redox-cofactor balancing constrains product yields in anaerobic fermentation processes. This challenge is exemplified by the formation of glycerol as major by-product in yeast-based bioethanol production, which is a direct consequence of the need to reoxidize excess NADH and causes a loss of conversion efficiency. Enabling the use of CO2 as electron acceptor for NADH oxidation in heterotrophic microorganisms would increase product yields in industrial biotechnology. Results A hitherto unexplored strategy to address this redox challenge is the functional expression in yeast of enzymes from autotrophs, thereby enabling the use of CO2 as electron acceptor for NADH reoxidation. Functional expression of the Calvin cycle enzymes phosphoribulokinase (PRK) and ribulose-1,5-bisphosphate carboxylase (Rubisco) in Saccharomyces cerevisiae led to a 90% reduction of the by-product glycerol and a 10% increase in ethanol production in sugar-limited chemostat cultures on a mixture of glucose and galactose. Co-expression of the Escherichia coli chaperones GroEL and GroES was key to successful expression of CbbM, a form-II Rubisco from the chemolithoautotrophic bacterium Thiobacillus denitrificans in yeast. Conclusions Our results demonstrate functional expression of Rubisco in a heterotrophic eukaryote and demonstrate how incorporation of CO2 as a co-substrate in metabolic engineering of heterotrophic industrial microorganisms can be used to improve product yields. Rapid advances in molecular biology should allow for rapid insertion of this 4-gene expression cassette in industrial yeast strains to improve production, not only of 1st and 2nd generation ethanol production, but also of other renewable fuels or chemicals.","metabolic engineering; synthetic biology; rubisco; ribulose-1,5-bisphosphate carboxylase; phosphoribulokinase; NADH re-oxidation; carbon dioxide fixation; Saccharomyces cerevisiae; glycerol; bioethanol","en","journal article","BioMed Central","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:752ea957-1808-44b0-aae7-6f9595471651","http://resolver.tudelft.nl/uuid:752ea957-1808-44b0-aae7-6f9595471651","Welcome to The Green Village","Van Wijk, A.J.M.","","2013","A sustainable world can only be achieved by an open collaboration between science, business and the public. That is why we create the Green Village: an innovative, lively, interactive and challenging environment where entrepreneurs, innovators, companies, artists, teachers and visitors can meet, work and play to develop, apply and experience innovative sustainable products and solutions. In the Green Village you will find Future Labs for paradigmshifting system research, resulting in icon projects such as the Car Park Power Plant, the Harp and the Energy Wall. The Green Village will be sustainably powered by the Engines, with ‘heart’, ‘veins’ and ‘lungs’ that supply energy and water, treat waste water and solid waste into useful new products and provide energy and transport fuels like electricity and hydrogen. It will also house the Greentech Store, an innovative co-making shop for 3D printing, apps, crowd funding and more. And it will be the stage for many sustainability Events: exhibitions, shows, contests, workshops, games, challenges, conferences, etcetera. The Green Village is located at Delft Campus, enabled by Delft University of Technology and empowered by a lively online community of scientists, entrepreneurs and you! Its vision: “Creating a sustainable, lively and entrepreneurial environment where we discover, learn and show how to solve society’s urgent challenges”. This book is sponsored by the OA fund TU Delft.","The Green Village; Future Labs; Engines; GreenTech Store; Energy; Societys Urgent Challenges; Circular Economy; Green Economy; Sustainable Environment; Car as Power Plant; Led Revolution; AC DC; The Harp; Car Park Power Plant; The Energy Wall; OA-Fund TU Delft","en","book","IOS Press under the imprint Delft University Press","","","","","","","","Applied Sciences","","","","",""
"uuid:29be1c2d-89c3-4521-a526-e6e1f74c1d98","http://resolver.tudelft.nl/uuid:29be1c2d-89c3-4521-a526-e6e1f74c1d98","The coexistence of engineering meanings of function: Four responses and their methodological implications","Vermaas, P.E.","","2013","In this position paper, the ambiguity of functional descriptions in engineering is considered from a methodological point of view. Four responses to this ambiguity are discussed, ranging from defining a single meaning of function and rejecting the different meanings that are currently used in engineering to accepting these meanings as coexisting in engineering and taking function as a family resemblance concept. Rejecting the different meanings is described as the straightforward response to resolving the ambiguity of functional descriptions, yet in engineering research and design methodology it rather seems to be accepted that engineers do use the coexisting meanings side by side. In this paper, explanations are given of why this practice is beneficial to engineering. Then it is explored how the particular meaning that engineers attach to function depends on the tasks for which functional descriptions are used. Finally, the methodological implications of the four responses to the ambiguity of functional descriptions are discussed.","ambiguity of functional descriptions; conceptual analysis; engineering design methods; functions","en","journal article","Cambridge University Press","","","","","","","2014-01-24","Technology, Policy and Management","Values and Technology","","","",""
"uuid:73e1f001-2616-47ba-9e83-83a386009d73","http://resolver.tudelft.nl/uuid:73e1f001-2616-47ba-9e83-83a386009d73","An Ontology-Based Approach for Knowledge Lifecycle Management within Aircraft Lifecycle Phases","Verhagen, W.J.C.","Curran, R. (promotor)","2013","In the aerospace domain, manufacturers and operators constantly seek to improve their products and processes. Increasingly, knowledge-based applications are developed to support or automate knowledge-intensive engineering tasks, saving time and money. However, engineering knowledge changes over time, which has implications for the usability and maintainability of knowledge-based applications. The research presented in this thesis contributes to the development of theory regarding knowledge change in engineering tasks. A conceptual knowledge lifecycle model to characterise and quantify knowledge change is presented. Additionally, this thesis proposes a methodology and an ontology-based approach to support the development of robust knowledge-based applications that can cope with knowledge change. These research contributions are validated in three case studies that consider engineering tasks in the aircraft design, manufacturing and maintenance lifecycle phases. The case studies demonstrate the utility of knowledge lifeycle management as usability and maintainability of knowledge-based applications are improved.","knowledge; knowledge change; knowledge-based applications; KBE; aircraft engineering; knowledge management; knowledge lifecycle; ontology","en","doctoral thesis","BOXPress","","","","","","","2013-07-18","Aerospace Engineering","Air Transport & Operations","","","",""
"uuid:dba8be6b-b107-4900-b82b-8b675c146590","http://resolver.tudelft.nl/uuid:dba8be6b-b107-4900-b82b-8b675c146590","Structuring of early design decisions in large infrastructure tenders: How to find the optimal design?","Van der Meer, J.P.; Hartmann, A.; Van der Horst, A.Q.C.; Dewulf, G.P.M.R.","","2013","Decision making in the tender phase of large infrastructural projects is a complex task for contractors as they have to make design decisions with long term effects and based on complex client requirements. Further complexity is added by the constrained environment of a tender and the uncertainty of winning the tender. As the context and the project are unique, there are no standard models for organizing the decision making during a tender. The introduction of Systems Engineering (SE) in the construction industry has led to a more structured way of working, but the application of the methods in the tender phase does not provide a suitable structure for organizing the decision making. As a result contractors struggle with designing an optimal design solution that will convince the client but will also reduce the risks associated with the construction and maintenance of the solution. In this paper we explore the implementation difficulties of SE in a large infrastructural tender. We report our initial findings of this in-depth single case study comprising document studies and open interviews with the tender team. We found that the allocation of design responsibilities between subsystems hampers cooperation for the integration of design and that the used SE approach lacks guidance for organizing a collaborative design process. We make propositions for further research and recommendations based on these initial findings.","infrastructure tenders; design decisions; systems engineering","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:f4f667d3-12d5-4531-a1be-c8391fec144f","http://resolver.tudelft.nl/uuid:f4f667d3-12d5-4531-a1be-c8391fec144f","Resonance characteristics of tides in branching channels","Alebregtse, N.C.; De Swart, H.E.; Schuttelaars, H.M.","","2013","","coastal engineering; shallow water flows; surface gravity waves","en","journal article","Cambridge University Press","","","","","","","2014-07-09","Electrical Engineering, Mathematics and Computer Science","Delft Institute of Applied Mathematics","","","",""
"uuid:51f6f87b-ba10-49ab-85b2-76cc3dd5b488","http://resolver.tudelft.nl/uuid:51f6f87b-ba10-49ab-85b2-76cc3dd5b488","Cities ready for energy crisis: Building urban energy resilience","Van den Dobbelsteen, A.A.J.F.; Keeffe, G.; Tillie, N.M.J.D.","","2013","Various sources indicate that threats to modern cities lie in the availability of essential streams, among which energy. Most cities are strongly reliant on fossil fuels; not one case of a fully self-sufficient city is known. Engineering resilience is the rate at which a system returns to a single steady or cyclic state following a perturbation. Certain resilience, for the duration of a crisis, would improve the urban capability to survive such a period without drastic measures. The capability of cities to prepare for and respond to energy crises in the near future is supported by greater or temporary self-sufficiency. The objective of the underlying research is a model for a city – including its surrounding rural area – that can sustain energy crises. Therefore, accurate monitoring of the current urban metabolism is needed for the use of energy. This can be used to pinpoint problem areas. Furthermore, a sustainable energy system is needed, in which the cycle is better closed. This will require a three-stepped approach of energy savings, energy exchange and sustainable energy generation. Essential is the capacity to store energy surpluses for periods of shortage (crises). The paper discusses the need for resilient cities and the approach to make cities resilient to energy crises.","engineering resilience; energy crisis; urban energy system; self-sufficiency; urban metabolism","en","conference paper","CIB (International Council for Research and Innovation in Building and Construction)","","","","","","","","Architecture","Architectural Engineering +Technology","","","",""
"uuid:7502bd44-a352-467b-b939-ff9fa4131e62","http://resolver.tudelft.nl/uuid:7502bd44-a352-467b-b939-ff9fa4131e62","Considering cognitive aspects in designing cyber cyber-physical systems: An emerging need for transdisciplinarity","Van der Vegte, W.F.; Vroom, R.W.","","2013","","cognitive engineering; mental models; cognitive architectures; cyber physical systems; information-intensive products","en","conference paper","University of Luxembourg","","","","","","","","Industrial Design Engineering","","","","",""
"uuid:3d2037f0-001b-4426-8c0e-463df9dd78ed","http://resolver.tudelft.nl/uuid:3d2037f0-001b-4426-8c0e-463df9dd78ed","The sand engine: A solution for vulnerable deltas in the 21st century?","Stive, M.J.F.; De Schipper, M.A.; Luijendijk, A.P.; Ranasinghe, R.W.M.R.J.B.; Van Thiel De Vries, J.S.M.; Aarninkhof, S.; Van Gelder-Maas, C.; De Vries, S.; Henriquez, M.; Marx, S.","","2013","The Netherlands’ strategy to combat coastal erosion since 1990 has been through nourishment, initially as beach nourishments but more and more as shoreface nourishments. In the light of sea level rise projections the yearly nourishment magnitudes continue to increase. In view of this an innovative soft engineering intervention, comprising an unprecedented 21 Mm3 sand nourishment known as the Sand Engine, has recently been implemented in the Netherlands. The Sand Engine nourishment is a pilot project to test the effectiveness and efficiency of a local meganourishment as a measure to account for the anticipated increased coastal recession in this century. The proposed concept, a single mega-nourishment, once every 20 years, is expected to be more efficient and effective in the long term than traditional beach and shoreface nourishments, presently being used at the Dutch coast with typically a three to five year interval. While the judgement is still out on this globally unique intervention, if proven successful, it may well become a generic solution for combating sea level rise driven coastal recession on open and vulnerable coasts.","nourishment; coastal erosion; sea level rise; storm erosion; shoreface processes; flooding; sand engine","en","conference paper","Bordeaux University","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:f08e4b47-7418-440d-b6be-42ab3160d0de","http://resolver.tudelft.nl/uuid:f08e4b47-7418-440d-b6be-42ab3160d0de","Characterization of distributed damage and self-healing in cementitous materials based on time-dependent 3-D x-ray computed microtomography (Micro-CT)","Fan, S.; Li, M.","","2013","Concrete cracking is inevitable, and can be the result of one or a combination of factors such as dry shrinkage, thermal contraction, fatigue, and embedded steel corrosion. The presence of cracks leads to further deterioration, service life reduction of concrete infrastructure, and frequent maintenance and repairs. These challenges can be potentially addressed with innovative self-healing cementitious materials, which can autogenously regain material transport properties as well as mechanical characteristics after the damage self-healing process. For the development of self-healing cementitious materials, it is crucial to precisely characterize the extent and quality of self-healing due to a variety of factors. X-ray computed microtomography (Micro-CT) was adopted in this study to derive threedimensional tomographic data of micro-cracks before and after healing in engineered cementitious composite (ECC) materials. This method is a non-destructive visualizing technique that allows digitalization and monitoring of the interior characteristics of solid objects. ECC specimens were pre-damaged under bending to form multiple micro-cracks, and then exposed to wet-dry cycles to allow potential self-healing to occur. Micro-CT was then employed to build 3-D tomography models of the samples. The 3-D microcrack geometry, width and area were quantified. The extent of selfhealing was then determined. The results were further combined with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) to characterize crystalline and chemical properties of the self-healing products. This study showed that Micro-CT is a suitable advanced technique to directly quantify self-healing potential in solid materials. The Micro-CT results revealed that selfhealing extent of ECC is strongly influenced by crack width. For a bending crack with surface crack width of 30 ?m, 55.3% of the crack volume was healed after 5 wet-dry cycles. For a bending crack with surface crack width of 100 ?m , only 7% of the crack volume was healed after 5 wet-dry cycles. Hence, controlling microcrack width to under 30 ?m is a necessary condition for achieving early, robust self-healing in ECC.","x-ray computed microtomography; nondestructive; damage; self-healing; engineered cementitious composites","en","conference paper","","","","","","","","","","","","","",""
"uuid:3417ec3a-60bc-49d3-a936-e18b3585e304","http://resolver.tudelft.nl/uuid:3417ec3a-60bc-49d3-a936-e18b3585e304","Methodology to evaluate availability of self-healing agent for structural ceramics","Yoshioka, S.; Nakao, W.","","2013","Simple methodorogy to evaluate availability of self-healing agent have been established from the investigation on the relationship between oxidation behavior of self-healing agent and self-healing phenomena. The consistency of the established methodology was discussed by comparison in the lower bound of the available temperature range of mullite / TiSi2 composite. From TG / DTA analysis, the available temperature range for 10 h healing (TH-10h est) was estimated to be 563 oC. On the other hand, the value of the lower bound of the available temperature range for 10 h healing (TH-10h exp) was experimentally determined to be 600 oC from strength recovery tests. These values showed a good consistency. Also, the data on 1 h healing of mullite / TiSi2 and the reference data on alumina /SiC self-healing ceramics exhibited good consistency. Therefore, the proposed methodology is sufficient for evaluating the advanced healing agent.","self-healing; Ceramic Matrix Composite; jet engine; oxidation; TG-DTA; analysis","en","conference paper","","","","","","","","","","","","","",""
"uuid:ed354c6b-c3e0-44c6-95b0-3cc5ab527b95","http://resolver.tudelft.nl/uuid:ed354c6b-c3e0-44c6-95b0-3cc5ab527b95","Educating engineering practice in six design projects in a row","Kamp, A.","","2013","Tomorrow’s engineers are required to have a good balance between deep working knowledge of engineering sciences and engineering skills. In the Bachelor in Aerospace Engineering at TU Delft, students are educated to master these competences so that they are ready to engineer when they graduate. The bachelor curriculum has three mainstreams of about equal study load: Aerospace Design, Aerospace Engineering & Technology, and Basic Engineering Sciences. The Aerospace Design stream is built up semester after semester of a design project and an accompanying design course. The main objectives of the design projects are related to contextual learning, learning by doing together, and learning and practicing academic and engineering skills, and being a mental organiser for the students. Over the years of study the design projects increase in complexity and openness, from knowing to application and synthesis, from tangible to abstract, from monoto multidisciplinary, and from mostly individual to team work. All projects exploit the factors that promote intrinsic motivation (challenge, curiosity, control, fantasy, competition, cooperation, and recognition). To assure that the intrinsic motivation factors and the semester themes are well addressed, each design project is characterised by a storyline, professional role, client, real-life problem, engineering process, and certain attainment levels of engineering skills. The projects make use of student project spaces in a dedicated building for collaborative learning, and laboratories like wind tunnels, a structures and materials laboratory, a study collection of aircraft and spacecraft parts and subsystems, and a flight simulator.","project education; project-based learning; experiential learning; aerospace engineering; design education; integrated curriculum; intrinsic motivation","en","conference paper","MIT & Harvard University","","","","","","","","Aerospace Engineering","Support Aerospace Engineering","","","",""
"uuid:64161304-4714-4214-9790-e0da4a71399d","http://resolver.tudelft.nl/uuid:64161304-4714-4214-9790-e0da4a71399d","Confidence in Coastal Forecasts","Baart, F.","Stive, M.J.F. (promotor)","2013","This thesis answers the question ""How can we show and improve our confidence in coastal forecasts?"", by providing four examples of common coastal forecasts. The first example shows how to improve the estimate of the one in ten thousand year storm-surge level. The three dimensional reconstruction, based on paintings, shows that structural erosion allowed the sea to swallow the church of Egmond aan Zee in 1741. Storm surges as big as those in the 18th century have not been seen in the last century. Including the largest storm surges of the 18th century results in a 10cm higher storm-surge level estimate. The second example of a confidence interval shows that since the 1990 policy change (increased nourishments) the structural erosion is now reversed into structural accretion at the Holland Coast. The third example is the estimate of sea-level rise. Since the 1950s it was predicted several times that sea level at the Dutch coast will accelerate. So far, this did not happen. It is shown that the recent acceleration in Dutch sea-level rise is not due to climate change but due to the 18.6 year tide, reducing the confidence in these predictions. The final example is the extension of the operational forecast system with forecasts of coastal morphology, including confidence bands. To be able to warn citizens when a dune is about to fail, during a storm, it is important that we can predict coastal morphological changes several days ahead. The system was tested using four recent storms, which showed that the coastal changes can be predicted up to three days ahead with reasonable skill. For providing warnings of possible dune failure this is almost enough. To answer the question ""how to show confidence?"" a checklist for forecasts is presented. To answer the question ""how to improve our confidence"", it is discussed that from all the improvements in the scientific method, those that assume biased scientists have not found their way into the coastal forecasts. To improve confidence, coastal managers, the doctor of the coast, together with coastal researchers should further adopt the ""evidence based practice”.","statistics; coastal morphology; coastal engineering; scientific method; research methods; forecasts","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:b9228696-2c50-4c9b-8358-1c0fa65f7e8c","http://resolver.tudelft.nl/uuid:b9228696-2c50-4c9b-8358-1c0fa65f7e8c","Flexible gas infrastructures","Herder, P.M.; Pulles, K.","","2013","","flexibility; uncertainty; gas infrastructure; systems engineering","en","conference paper","Springer","","","","","","","","Technology, Policy and Management","Infrastructures, Systems and Service","","","",""
"uuid:34a51f6a-a286-42ed-b9f1-2c9221b10ec3","http://resolver.tudelft.nl/uuid:34a51f6a-a286-42ed-b9f1-2c9221b10ec3","Test Suite Comprehension for Modular and Dynamic Systems","Greiler, M.S.","Van Deursen, A. (promotor)","2013","The two main topics of this dissertation are plug-in-based systems and test suite comprehension. In particular, challenges during testing plug-in-based systems are revealed, and reverse engineering based techniques to support developers during test suite comprehension are presented.","static analysis; dynamic analysis; reverse engineering; plug-in systems; test comprehension; software comprehension; testing practices","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:437fef30-6904-481d-a572-bf107ef1ac3a","http://resolver.tudelft.nl/uuid:437fef30-6904-481d-a572-bf107ef1ac3a","Shear capacity of slabs under a combination of loads","Lantsoght, E.O.L.; Van der Veen, C.; Walraven, J.C.","","2013","Existing solid slab bridges under a combination of wheel loads and distributed traffic loads sometimes do not fulfil the code requirements for shear. However, reinforced concrete slabs loaded close to the support are subjected to shear stresses which might result in a failure mode of combined punching and shear. This behaviour is studied in a first series of experiments on slabs under a concentrated load close to the support, and these experiments resulted in a set of recommendations. To verify if these recommendations can be used when assessing solid slab bridges under distributed and concentrated loads, slabs under a combination of a line load, representing the dead weight, and a concentrated load, representing a wheel load, are tested up to failure. The experimental results are used to assess the ultimate shear which can be carried at the support and the influence of the varied parameters is discussed. The results demonstrate how different types of loading such as dead loads and live loads can be superposed and how a stress check at the support can be carried out.","bridge engineering; design; effective width; experiments; punching; shear; slabs","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:ae07be2d-7030-409a-8e9e-0b60d829ce14","http://resolver.tudelft.nl/uuid:ae07be2d-7030-409a-8e9e-0b60d829ce14","Genome-scale analyses of butanol tolerance in Saccharomyces cerevisiae reveal an essential role of protein degradation","Gonzalez-Ramos, D.; Van den Broek, M.; Van Maris, A.J.A.; Pronk, J.T.; Daran, J.M.G.","","2013","Background n-Butanol and isobutanol produced from biomass-derived sugars are promising renewable transport fuels and solvents. Saccharomyces cerevisiae has been engineered for butanol production, but its high butanol sensitivity poses an upper limit to product titers that can be reached by further pathway engineering. A better understanding of the molecular basis of butanol stress and tolerance of S. cerevisiae is important for achieving improved tolerance. Results By combining a screening of the haploid S. cerevisiae knock-out library, gene overexpression, and genome analysis of evolutionary engineered n-butanol-tolerant strains, we established that protein degradation plays an essential role in tolerance. Strains deleted in genes involved in the ubiquitin-proteasome system and in vacuolar degradation of damaged proteins showed hypersensitivity to n-butanol. Overexpression of YLR224W, encoding the subunit responsible for the recognition of damaged proteins of an ubiquitin ligase complex, resulted in a strain with a higher n-butanol tolerance. Two independently evolved n-butanol-tolerant strains carried different mutations in both RPN4 and RTG1, which encode transcription factors involved in the expression of proteasome and peroxisomal genes, respectively. Introduction of these mutated alleles in the reference strain increased butanol tolerance, confirming their relevance in the higher tolerance phenotype. The evolved strains, in addition to n-butanol, were also more tolerant to 2-butanol, isobutanol and 1-propanol, indicating a common molecular basis for sensitivity and tolerance to C3 and C4 alcohols. Conclusions This study shows that maintenance of protein integrity plays an essential role in butanol tolerance and demonstrates new promising targets to engineer S. cerevisiae for improved tolerance.","saccharomyces cerevisiae; butanol tolerance; evolutionary engineering; deletion collection screening; whole genome sequencing; proteasome; multivesicular bodies; OA-Fund TU Delft","en","journal article","BioMed Central","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:7561eca7-a0f4-4d20-9ed5-cec61e2f263c","http://resolver.tudelft.nl/uuid:7561eca7-a0f4-4d20-9ed5-cec61e2f263c","A systems description of flow through porous media","Jansen, J.D.","","2013","This text forms part of material taught during a course in advanced reservoir simulation at Delft University of Technology over the past 10 years. The contents have also been presented at various short courses for industrial and academic researchers interested in background knowledge needed to perform research in the area of closed-loop reservoir management, also known as smart fields, related to e.g. model-based production optimization, data assimilation (or history matching), model reduction, or upscaling techniques. Each of these topics has connections to system-theoretical concepts. The introductory part of the course, i.e. the systems description of flow through porous media, forms the topic of this brief monograph. The main objective is to present the classic reservoir simulation equations in a notation that facilitates the use of concepts from the systems-and-control literature. Although the theory is limited to the relatively simple situation of horizontal two-phase (oil-water) flow, it covers several typical aspects of porous-media flow. The first chapter gives a brief review of the basic equations to represent single-phase and two-phase flow. It discusses the governing partial-differential equations, their physical interpretation, spatial discretization with finite differences, and the treatment of wells. It contains well-known theory and is primarily meant to form a basis for the next chapter where the equations will be reformulated in terms of systems-and-control notation. The second chapter develops representations in state-space notation of the porous-media flow equations. The systematic use of matrix partitioning to describe the different types of inputs leads to a description in terms of nonlinear ordinary-differential and algebraic equations with (state-dependent) system, input, output and direct-throughput matrices. Other topics include generalized state-space representations, linearization, elimination of prestart from escribed pressures, the tracing of stream lines, lift tables, computational aspects, and the derivation of an energy balance for porous-media flow. The third chapter first treats the analytical solution of linear systems of ordinary differential equations for single-phase flow. Next it moves on to the numerical solution of the two-phase flow equations, covering various aspects like implicit, explicit or mixed (IMPES) time discretizations and associated stability issues, Newton-Raphson iteration, streamline simulation, automatic time-stepping, and other computational aspects. The chapter concludes with simple numerical examples to illustrate these and other aspects such as mobility effects, well-constraint switching, time-stepping statistics, and system-energy accounting. The contents of this text should be of value to students and researchers interested in the application of systems-and-control concepts to oil and gas reservoir simulation and other applications of subsurface flow simulation such as CO2 storage, geothermal energy, or groundwater remediation.","porous-media flow; subsurface flow; systems and control; numerical simulation; reservoir simulation; reservoir engineering; petroleum engineering; smart fields","en","book","Springer","","","","","","","","Civil Engineering and Geosciences","Geoscience and Engineering","","","",""
"uuid:356521e9-b37d-4a45-9cfc-c88d47b2df83","http://resolver.tudelft.nl/uuid:356521e9-b37d-4a45-9cfc-c88d47b2df83","MAIA: A framework for developing agent-based social simulations","Ghorbani, A.; Bots, P.W.G.; Dignum, V.; Dijkema, G.P.J.","","2013","","modelling language; model-driven engineering; institutions; social simulation; meta-model","en","journal article","SimSoc Consortium","","","","","","","","Technology, Policy and Management","Infrastructures, Systems and Services","","","",""
"uuid:1b1c2e9a-2c6e-4aa2-815c-cdff3440851c","http://resolver.tudelft.nl/uuid:1b1c2e9a-2c6e-4aa2-815c-cdff3440851c","Biogeochemical processes and geotechnical applications: Progress, opportunities and challenges","De Jong, J.T.; Soga, K.S.; Kavazanjian, E.; Burns, S.; Van Paassen, L.A.; Al Quabany, A.; Aydilek, A.; Bang, S.S.; Burbank, M.; Caslake, L.F.; Chen, C.Y.; Cheng, X.; Chu, J.; Ciurli, S.; Esnault-Filet, A.; Fauriel, S.; Hamdan, N.; Hata, T.; Inagaki, Y.; Jefferis, S.; Kuo, M.; Laloui, L.; Larrahondo, J.; Manning, D.A.C.; Martinez, B.; Montoya, B.M.; Nelson, D.C.; Palomino, A.; Renforth, P.; Santamarina, J.C.; Seagren, E.A.; Tanyu, B.; Tsesarsky, M.; Weaver, T.","","2013","Consideration of soil as a living ecosystem offers the potential for innovative and sustainable solutions to geotechnical problems. This is a new paradigm for many in geotechnical engineering. Realising the potential of this paradigm requires a multidisciplinary approach that embraces biology and geochemistry to develop techniques for beneficial ground modification. This paper assesses the progress, opportunities, and challenges in this emerging field. Biomediated geochemical processes, which consist of a geochemical reaction regulated by subsurface microbiology, currently being explored include mineral precipitation, gas generation, biofilm formation and biopolymer generation. For each of these processes, subsurface microbial processes are employed to create an environment conducive to the desired geochemical reactions among the minerals, organic matter, pore fluids, and gases that constitute soil. Geotechnical applications currently being explored include cementation of sands to enhance bearing capacity and liquefaction resistance, sequestration of carbon, soil erosion control, groundwater flow control, and remediation of soil and groundwater impacted by metals and radionuclides. Challenges in biomediated ground modification include upscaling processes from the laboratory to the field, in situ monitoring of reactions, reaction products and properties, developing integrated biogeochemical and geotechnical models, management of treatment by-products, establishing the durability and longevity/reversibility of the process, and education of engineers and researchers.","chemical properties; environmental engineering; ground improvement; remediation; soil stabilisation","en","journal article","ICE Publishing","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:6d740180-9609-46cb-a403-7904f9a4b1d5","http://resolver.tudelft.nl/uuid:6d740180-9609-46cb-a403-7904f9a4b1d5","Enhancing Socially Responsible Innovation in Industry: Practical Use for Considerations of Social and Ethical Aspects in Industrial Life Science & Technology","Flipse, S.M.","Osseweijer, P. (promotor)","2013","The aim of the study presented in this thesis is to explore to what extent corporate researchers in the field of industrial Life Science & Technology (LST) can consider social and ethical aspects of LST innovation to improve their Research and Development (R&D) practices. Innovators, particularly those working in controversial scientific and technology fields such as industrial LST, are encouraged to adopt socially responsible innovation methods. This requires that researchers, who work in such fields, consider the broader social and ethical context of their R&D activities. This thesis explores first how corporate researchers can integrate such aspects in their daily work and how this could improve their work. Second it investigates whether such integration leads to a quantitatively assessable improvement of the quality of R&D work. The results indicate that integration is possible, and leads to a measurable improvement of the quality of R&D work. In addition, researchers see a number of improvements in their R&D work, e.g. in the quality of communication and cooperation, and how to link their own work to corporate strategies and marketing. This thesis can be useful for innovators who wish to enhance socially responsible innovation practices, as it presents a tool that allows for the operationalisation of socially responsible innovation for R&D management and improved R&D performance.","Socially Responsible Innovation; Corporate Social Responsibility; Engineering Ethics","en","doctoral thesis","","","","","","","","2013-01-21","Applied Sciences","Biotechnology","","","",""
"uuid:df91501f-655f-4c92-803a-4e1340bcd29f","http://resolver.tudelft.nl/uuid:df91501f-655f-4c92-803a-4e1340bcd29f","Taking a Capability Approach to Technology and Its Design: A Philosophical Exploration","Oosterlaken, E.T.","Van den Hoven, M.J. (promotor); Roeser, S. (promotor)","2013","What people are realistically able to do and be in their lives, their capabilities, are of central moral importance according to the capability approach (CA) of Amartya Sen and Martha Nussbaum. Examples are the capabilities to be healthy or to be part of a community. The CA has become an influential normative framework for reflecting on justice, equality, well-being and development. In the past decades it has been successfully applied to areas such as education and health care. Only quite recently have scholars started to use the CA to reflect on technology, for example on the contribution of ICT to development in the Global South (ICT4D). Much of this work is empirical. This dissertation contributes to the theoretical foundations for future empirical and ethical work by providing a philosophical exploration of how the CA can be brought to bear on technology. It discusses the applicability and added value of the CA for the design of technical artifacts (‘capability sensitive design’), for the evaluation of technological development projects, and for the assessment of technology from the perspective of the good life. One main question addressed in this dissertation is which technology theories and design approaches could fruitfully supplement the CA, in order to ‘operationalize’ it in this new area. For this purpose participatory design, value sensitive design, the use plan account of technical artifacts, inclusive/universal design, actor-network theory, appropriate technology, pluralist theories of technology and the system/network view of technology are discussed. Another guiding question is what the exact nature is of (a) human capabilities as discussed in the CA, and (b) technology in the sense of technical artifacts, and how we can then conceptualize the relation between them. It is argued that we need to regularly move back and forth between ‘zooming in’ and ‘zooming out’. The former allows us to see the details of design of technical artifacts, the latter how exactly technical artifacts are embedded in broader socio-technical networks. Both, it is claimed, are crucial for the expansion of human capabilities.","capability approach; development; technology; engineering design; Amartya Sen; Martha Nussbaum; the good life; design for development; human capabilities; ethics of technology; philosophy of technology; value sensitive design","en","doctoral thesis","3TU.Centre for Ethics and Technology","","","","","","","","Technology, Policy and Management","Philosophy section, department of values & technology","","","",""
"uuid:18804943-4286-45c6-a95f-6d4fab427a03","http://resolver.tudelft.nl/uuid:18804943-4286-45c6-a95f-6d4fab427a03","Supplier's sales engineer as a knowledge worker","Kopecka, J.A.; Santema, S.C.; Hultink, H.J.","","2012","The paper forms part of a multiple case study in progress that focuses on information relationships, i.e., the exchange of information and knowledge at the micro-social level between supplier and buyer firms in the fuzzy front end of product development. The micro-social level is made up of dyadic information relationships between the Design Engineer of buyer firms and the Sales Engineer of supplier firms. The case study explores the information relationship through the lens of three theoretical perspectives, namely: early supplier involvement in product development, knowledge management, and the concepts of social embeddedness and tie strengths belonging to economic sociology. The paper describes the concept of supplier’s Sales Engineer as a knowledge worker, and explains how the concept represents a specific type of supplier involvement in early product development. By using the preliminary findings of four case studies, the paper shows how the concept of the Sales Engineer as a knowledge worker has been understood and applied in practice The paper concludes with managerial implications regarding the conditions that need to be in place in order to make the knowledge transfer through the Sales Engineer robust and dependable.","suppliers sales engineer, design engineer, product development, knowledge transfer, socialties","en","conference paper","IPSERA","","","","","","","","Industrial Design Engineering","Product Innovation Management","","","",""
"uuid:d66209a5-c7d6-4f7e-aed8-f4b5fc21a165","http://resolver.tudelft.nl/uuid:d66209a5-c7d6-4f7e-aed8-f4b5fc21a165","Evaluation of a ubiquitous learning system in a design engineering environment","Vroom, R.W.; Horvath, I.; Rusak, Z.; De Smit, A.; Opiyo, E.Z.","","2012","Ubiquitous computing is computing power that is integrated in devices and environments in such a way that they offer optimal support to human daily life activities. For industrial design engineering students, applying ubiquitous technologies offer a great opportunity and challenge for innovating everyday products. To teach the students about ubiquitous technologies and their application in design, we have done an exercise called “Innovate with ubiquitous technologies!” with more than 100 students in our Advanced Design Support-course. The exercise is threefold. The first task for the students is to find information on the Internet about ubiquitous technologies and to share the information found by writing about the collected information in an open content repository (WikID, our industrial design engineering wiki). In the second part of the practical exercise, the students have to create a concept for an incremental innovation of an existing product, and produce an abstract prototype of this concept. They are given a digital computer-aided design model of a product and they have to extend this product by applying a combination of ubiquitous technologies with the goal to improve an aspect such as new functionality, function and price trade off, performance, energy consumption, information richness, and/or user experience. In the third part the students have to make a cost calculation, comparing the product with and without the ubiquitous technologies. For this exercise a design infrastructure, and knowledge sharing sessions have been established including mobile blogs and group sessions and the students have been provided with extended creativity triggering techniques, a knowledge framework for ubiquitous technologies, and design tools. This paper reports on the way these ubiquitous learning applications have been received by the students, and on the results achieved. We present student design cases to illustrate how the exercise has been carried out and to present the students opinions on this ubiquitous learning exercise.","Ubiquitous learning exercise and system; industrial design engineering; case studies; student's evaluation; incremental innovation; everyday products","en","conference paper","International Association of Technology, Education and Development (IATED)","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:1b31a6ee-d903-4fae-924a-ed0d3866be1f","http://resolver.tudelft.nl/uuid:1b31a6ee-d903-4fae-924a-ed0d3866be1f","Microbial Risk Assessment of Pathogens in Water","Medema, G.","","2012","","sustainable development; engineering; energy; pollution; chemistry/food science; medicine/public health","en","book chapter","Springer","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:6fd93f47-b0d6-48a9-9c6c-0852d82e3f9c","http://resolver.tudelft.nl/uuid:6fd93f47-b0d6-48a9-9c6c-0852d82e3f9c","Rethinking lessons learned processes","Buttler, T.; Lukosch, S.G.; Kolfschoten, G.L.; Verbraeck, A.","","2012","Lessons learned are one way to retain experience and knowledge in project-based organizations, helping them to prevent reinventin,g the wheel or to repeat past mistakes. However, there are several challenges that make these lessonts learned processes a challenging endeavor. These include capturing knowledge about project mai!Iagement, allowing learning from mistakes, and handling the group processes within the project team. We introduce a novel approach combining elements from storytelling, root cause analysis, and collaboration engineering to address these challenges, and report on first experiences utiliziing this approach in a project in the oil and gas industry.","Lessons Learned; Root Cause Analysis; Storytelling; Collaboration Engineering; Knowledge Management; Organizational Learning","en","conference paper","Editora Universitaria da UFPE","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:063e5504-cdbb-4ec9-9efc-3d727115a41e","http://resolver.tudelft.nl/uuid:063e5504-cdbb-4ec9-9efc-3d727115a41e","Analyzing the Impact of Antipatterns on Change-Proneness Using Fine-Grained Source Code Changes","Romano, D.; Raila, P.; Pinzger, M.; Khomh, F.","","2012","Preprint of paper published in: WCRE 2012 - Proceedings of the 19th Working Conference on Reverse Engineering, 15-18 October 2012; doi:10.1109/WCRE.2012.53 Antipatterns are poor solutions to design and implementation problems which are claimed to make object oriented systems hard to maintain. Our recent studies showed that classes with antipatterns change more frequently than classes without antipatterns. In this paper, we detail these analyses by taking into account fine-grained source code changes (SCC) extracted from 16 Java open source systems. In particular we investigate: whether classes with antipatterns are more change-prone (in terms of SCC) than classes without; (2) whether the type of antipattern impacts the change-proneness of Java classes; and (3) whether certain types of changes are performed more frequently in classes affected by a certain antipattern. Our results show that: 1) the number of SCC performed in classes affected by antipatterns is statistically greater than the number of SCC performed in classes with no antipattern; 2) classes participating in the three antipatterns ComplexClass, SpaghettiCode, and SwissArmyKnife are more change-prone than classes affected by other antipatterns; and 3) certain types of changes are more likely to be performed in classes affected by certain antipatterns, such as API changes are likely to be performed in classes affected by the ComplexClass, SpaghettiCode, and SwissArmyKnife antipatterns.","antipatterns; change-proneness; fine-grained source code changes; empirical software engineering","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Computer Technology","","","",""
"uuid:85a25098-e9d3-4262-931e-260e27a7ab82","http://resolver.tudelft.nl/uuid:85a25098-e9d3-4262-931e-260e27a7ab82","De novo production of the flavonoid naringenin in engineered Saccharomyces cerevisiae","Koopman, F.W.; Beekwilder, J.; Crimi, B.; Van Houwelingen, A.; Hall, R.D.; Bosch, D.; Van Maris, A.J.A.; Pronk, J.T.; Daran, J.M.","","2012","Background Flavonoids comprise a large family of secondary plant metabolic intermediates that exhibit a wide variety of antioxidant and human health-related properties. Plant production of flavonoids is limited by the low productivity and the complexity of the recovered flavonoids. Thus to overcome these limitations, metabolic engineering of specific pathway in microbial systems have been envisaged to produce high quantity of a single molecules. Result Saccharomyces cerevisiae was engineered to produce the key intermediate flavonoid, naringenin, solely from glucose. For this, specific naringenin biosynthesis genes from Arabidopsis thaliana were selected by comparative expression profiling and introduced in S. cerevisiae. The sole expression of these A. thaliana genes yielded low extracellular naringenin concentrations (<5.5 ?M). To optimize naringenin titers, a yeast chassis strain was developed. Synthesis of aromatic amino acids was deregulated by alleviating feedback inhibition of 3-deoxy-d-arabinose-heptulosonate-7-phosphate synthase (Aro3, Aro4) and byproduct formation was reduced by eliminating phenylpyruvate decarboxylase (Aro10, Pdc5, Pdc6). Together with an increased copy number of the chalcone synthase gene and expression of a heterologous tyrosine ammonia lyase, these modifications resulted in a 40-fold increase of extracellular naringenin titers (to approximately 200 ?M) in glucose-grown shake-flask cultures. In aerated, pH controlled batch reactors, extracellular naringenin concentrations of over 400 ?M were reached. Conclusion The results reported in this study demonstrate that S. cerevisiae is capable of de novo production of naringenin by coexpressing the naringenin production genes from A. thaliana and optimization of the flux towards the naringenin pathway. The engineered yeast naringenin production host provides a metabolic chassis for production of a wide range of flavonoids and exploration of their biological functions.","saccharomyces cerevisiae; naringenin; de novo; flavonoids; metabolic engineering; OA-Fund TU Delft","en","journal article","BioMed Central","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:dff70d1b-199f-406b-806e-03342e45c4da","http://resolver.tudelft.nl/uuid:dff70d1b-199f-406b-806e-03342e45c4da","Morphodynamic development and sediment budget of the Dutch Wadden Sea over the last century","Elias, E.P.L.; Van der Spek, A.J.F.; Wang, Z.B.; De Ronde, J.","","2012","The availability of nearly 100 years of bathymetric measurements allows the analysis of the morphodynamic evolution of the Dutch Wadden Sea under rising sea level and increasing human constraint. The historically observed roll-over mechanisms of landward barrier and coastline retreat cannot be sustained naturally due to numerous erosion control measures that have fixed the tidal basin and barrier dimensions. Nevertheless, the large continuous sedimentation in the tidal basins (nearly 600 million m3), the retained inlets and the similar channel-shoal characteristics of the basins during the observation period indicate that the Wadden Sea is resilient to anthropogenic influence, and can import sediment volumes even larger than those needed to compensate the present rate of sea-level rise. The largest sedimentation occurs in the Western Wadden Sea, where the influence of human intervention is dominant. The large infilling rates in closed-off channels, and along the basin shoreline, rather than a gradual increase in channel flat heights, render it likely that this sedimentation is primarily a response to the closure of the Zuiderzee and not an adaptation to sea-level rise. Most of the sediments were supplied by the ebb-tidal deltas. It is, however, unlikely that the sediment volume needed to reach a new equilibrium morphology in the Western Wadden Sea can be delivered by the remaining ebb-tidal deltas alone.","Wadden Sea; morphodynamics; tidal basins; ebb-tidal deltas; impact large-scale engineering works","en","conference paper","Netherlands Journal of Geosciences Foundation","","","","","","","2014-11-30","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:92123c07-cc12-4945-973f-103bd744ec87","http://resolver.tudelft.nl/uuid:92123c07-cc12-4945-973f-103bd744ec87","Engineering models in wind energy aerodynamics: Development, implementation and analysis using dedicated aerodynamic measurements","Schepers, J.G.","Van Bussel, G.J.W. (promotor); Van Kuik, G.A.M. (promotor)","2012","The subject of aerodynamics is of major importance for the successful deployment of wind energy. As a matter of fact there are two aerodynamic areas in the wind energy technology: Rotor aerodynamics and wind farm aerodynamics. The first subject considers the flow around the rotor and the second subject considers the (wake) flow within a wind farm. For both areas calculational models have been developed which are implemented i rotor design and wind farm design codes respectively. Accurate rotor design codes enable a reliable design of wind turbines and an optimization towards a higher energy production and lower loads, i.e. towards a lower cost of energy. They are also required to avoid design errors and hence to reduce investment risks of wind turbine manufacturers. Accurate wind farm design codes are needed to predict the production losses and the load increase on turbines in a farm due to wake effects. They also support the optimization of wind farms (e.g. through farm control) by which the energy losses and the load increase from wake effects (and consequently the costs/kWh) are minimized. For both areas the complexity of models range from engineering methods to very advanced Computational Fluid Dynamics (CFD) methods. The term engineering method is meant to indicate a model which casts a complicated flow phenomenon into a transparent form. This generally goes together with an economic computer usage. In this respect it is very important to realize that wind energy design calculations are inherently very time consuming by which advanced CFD models are still beyond the routine possibilities of industry. As such engineering methods form the only alternative for that purpose. The main aim of the present thesis is then to describe several developments of the last 25 years which have led to the present generation of aerodynamic engineering models. It will be shown that much progress has been made both on the field of rotor aerodynamics as well as on the field of wind farm aerodynamics and that this progress was highly supported by the fact that dedicated aerodynamic measurement data have become available. The progress is illustrated by the engineering models which are developed and validated by ECN in several large (inter)national cooperation projects in which these measurements played an important role. The author of this thesis was heavily involved in these projects and often acted as coordinator. Since these projects were performed in close cooperation with other institutes (which used different types of models), the activities of the author can be placed in a wider context. The first part of the thesis is devoted to rotor aerodynamics. Basically the subject of rotor aerodynamics can be subdivided in two parts: The first part deals with the global flow field around a wind turbine. This type of modelling is called induction aerodynamics, since its main goal is to determine the induced velocities at the blade. The second part deals with the loads on a wind turbine blade as a response to this flow situation and is called blade aerodynamics. Current engineering models for rotor aerodynamics topic are built around the Blade Element Momentum (BEM) theory. The Blade Element Momentum theory in itself is very basic, e.g. it is derived for 2-dimensional, stationary, homogenous and non-yawed conditions. For this reason several engineering models have been developed which overcome these simplifications and which act as add-on's to the basic BEM theory. These engineering add-on's have been developed for the field of blade aerodynamics and for the field of induction aerodynamics. In this thesis a comparison is made between current engineering models and the engineering models from 25 years ago. The engineering methods from 25 years ago were not much more than the very basic BEM theory with a Prandtl tip loss correction and a turbulent wake correction. Moreover a tower shadow model based on a dipole model and a 'geometric' correction for cone and tilt angle were included, while yaw was modelled with the advancing and retreating blade effect only. Since then the models for airfoil aerodynamics have been improved by adding unsteady and three-dimensional effects. These unsteady effects can be divided in viscous dynamic stall effects and non-viscous effects at low angles of attack. The three-dimensional effects occur at the inner part of the blade where stall is delayed and at the outer part where the tip decreases the loads. In terms of induction aerodynamics, models have been added for dynamic inflow, the azimuthal variation of the induced velocity at yaw and a model for root losses. The progress in the rotor aerodynamic engineering models from ECN is mainly described along results of four subsequent IEA Tasks: IEA Task 14 and 18, IEA Task 20 and IEA Task 29(Mexnext). An IEA Task (sometimes called an IEA Annex) is a cooperative project carried out under auspices of the International Energy Agency IEA. The goal of IEA Tasks 14 and 18 was to create a database of detailed aerodynamic measurements which all have been taken on turbines under atmospheric conditions. The goal of IEA Task 20 was to analyze the measurements which have been taken by the National Renewable Energy Laboratory NREL on a 10 meter diameter wind turbine which was placed in the very large NASA-Ames wind tunnel. Finally IEA Task 29(Mexnext) analyzed the measurements which have been taken in the EU Project Mexico on a wind turbine rotor with a diameter of 4.5 meters placed in the Large Low Speed Facility (LLF) of the German Dutch Wind Tunnel (DNW). In all of these experimental programs pressure distributions were measured at different locations along the rotor blades. Moreover the Mexico experiment mapped the flow field upstream, in and downstream of the rotor plane. The detailed aerodynamic measurements from the IEA Tasks were found to be very useful in the development, improvement and validation of these engineering models because they made it possible to extract aerodynamic phenomena which are hidden in the very global information from conventional measurement programs. It is concluded that only detailed aerodynamic measurements may be used for validation of aerodynamic design models: A validation on basis of global turbine(blade) loads does not give a decisive answer on the accuracy of aerodynamic models due to the fact that 'compensating errors' may occur. Moreover it will be shown that the measurements revealed several shortcomings in aerodynamic engineering methods which partly could be 'repaired', sometimes with the help of more refined models. Several recommendations are made on rotor aerodynamics. This includes some specific further improvements which are still possible to the current state of engineering models. Amongst other things, models for the annulus averaged induction at yaw, tip loss effects and time constants at dynamic inflow can be improved further. These improvements can be established by calibrating engineering methods to results from more advanced aerodynamic models (e.g. CFD or free vortex wake methods). The background for this recommendation lies in the fact that the validation of these advanced aerodynamic models with the detailed aerodynamic measurements from the IEA Tasks showed a clear added value from such methods on these fields. Moreover it is concluded that three-dimensional and unsteady effects on the drag deserve more attention. However the most important recommendation is related to the observation of an unbalance in the aerodynamic wind energy society: Much effort is spent on the development of aerodynamic models (often of little mutual differences) but the amount of experimental validation material is (too) limited. Therefore it is recommended to intensify the activities on rotor aerodynamic measurements in both the wind tunnel and the field. Special attention should be paid to the measurement of those phenomena which, until now, are still largely concealed (e.g. boundary layer phenomena) or unclear (e.g. the relation between blade loads and underlying flow field which is found puzzling in the Mexico experiment). The present thesis also describes the progress which has been made on the field of wind farm aerodynamics. Opposite to the situation for rotor aerodynamics, where the BEM model can be appointed as the main model, the variety of models for wind farm aerodynamics is much larger. This is partly due to the fact that a wind farm aerodynamic model should cover much more aspects: It should model both the aerodynamic behavior of the rotor (which generates the wake) as well as the turbulent wake downstream of this rotor. The fact that calculational time is such an extreme constraint adds to the diversity: As a consequence CFD modelling of wind farm aerodynamics often only refers to the modelling of the wake and not to the modelling of the rotor. It also makes that wind farm and rotor aerodynamics are sometimes considered to be fully separate subjects. This is seen as an undesired development since the aerodynamics of the wake is largely determined by the aerodynamics of the rotor standing in front of the wake. In this thesis the main characteristics of the wake flow behind a wind turbine are described together with a survey of wind farm aerodynamic models. Most of the attention is focussed on an intermediate between the very basic models and the CFD codes, i.e. the parabolized wake models. These models are relatively economic in computer usage (by which they are still considered to be engineering models) where they model the so-called far wake in a physically accurate way. The disadvantage lies in the fact that they generally need an empirical treatment of the near wake. This again goes together with a very simple modelling of the rotor. The progress in wind farm aerodynamic models is then illustrated with ECN's wind farm design code Farmflow (based on the former Wakefarm wake model) which combines a parabolized k-epsilon turbulence model for the far wake with results from a physical free vortex wake method for the near wake. The measurements on wind farm aerodynamics used in this thesis mainly come from the ECN Wind Turbine Test Site Wieringermeer, EWTW. This research farm consists of five wind turbines in a line set up with a rated power of 2.5 MW and a rotor diameter and hub height of 80 meter. The turbines are extensively instrumented, where a meteorological mast is available to measure the free stream or the wake conditions. A major advantage of these measurements lies in the research environment by which data have been recorded over a very long period of high quality. The EWTW measurements revealed various new wake aerodynamic phenomena and they offered validation material for the improvement and validation of the Farmflow code. The observations on the EWTW farm are compared with those on large off-shore wind farms, the measurements of which were supplied within the EU project Upwind. In the EWTW line set-up the largest power loss due to wake effects (and hence the lowest overall power) appears at the second turbine in the farm. The turbines deeper in the farm have a slightly higher power. This is opposite to the situation in large off-shore wind farms where the power keeps decreasing for turbines deeper into the farm. This can be explained by lateral wake effects and the size of those large (array) wind farms. The power behavior in both the EWTW as well as in the large array wind farms was predicted well with Farmflow. Several conclusions on wind farm aerodynamics are drawn. The most important conclusion is that as for the situation on rotor aerodynamics, much progress has been achieved over the past decades. This is illustrated with the developments from Wakefarm to Farmflow. In the beginning of the 1990's only single wakes were considered. These were modelled with a very simple approach: The wind turbine was represented by an actuator disc with a near wake model based on momentum theory (and later empiricism). The far wake was modelled with a turbulence model tuned for non wind energy applications. Since then the near wake models has been refined and multiple wake effects are taken into account in both axial and lateral direction. Furthermore the turbulence model has been calibrated for wind turbine wake situations. For the development of wind farm engineering models in general it is very important that some CFD models entered the (research) scene in which the rotor is modelled with more advanced methods than the actuator disc approach (e.g. with actuator lines). Such advanced models can now be used for calibration of more simple models. Several subjects for wind farm aerodynamics have been identified which still need more attention. As such it is recommended to intensify research on these fields. This holds amongst other things for the validation and improvement of multiple wake models and near wake models in multiple wake situations. Also the interaction of wind farms with the outer atmosphere deserves more attention. Moreover there is a need to refine the turbulence models for wind farm aerodynamics. Another main question to be answered is the importance of rotor aerodynamics for wake aerodynamics. More specifically it should be determined whether it is justified to model the rotor as an actuator disc. The answer to this question can be found by comparing results from CFD codes, which models both the rotor and the wake in a detailed way, with results from a similar code in which the rotor is replaced by an actuator disc. As for the situation on rotor aerodynamics it is again concluded that progress on the field of wind farm aerodynamics is hampered by a shortage of high quality validation material. For this reason it is recommended to intensify the measurement activities for wind farm aerodynamics. In this thesis minimum requirements for such measurement programs are given. Measurements anyhow need to be done on full scale wind farms, preferably in combination with wind tunnel measurements. The first type of measurements yield representative information but generally lack a sufficient degree of detail for a complete interpretation of the wind farm aerodynamic problem. Furthermore field measurements are difficult to interpret due to the stochastic turbulent environment in the free atmosphere. The second type of measurements can yield very detailed and easy interpretable information but the scale of the model turbines is far too small. An interesting intermediate is then the so-called ECN scaled wind farm. This farm consists of 10 wind turbines with a rotor diameter of 7.6 m and a rated power of 10 kW. The farm is heavily instrumented where the size is sufficiently large to make the results at least to some extent, representative for full scale situations. The combination of full scale measurements, scaled farm measurements and wind tunnel measurements then forms the most complete experimental base for wind farm aerodynamics even though each type of measurements has its own drawbacks.","engineering models in wind energy aerodynamics","en","doctoral thesis","","","","","","","","2012-12-01","Aerospace Engineering","Wind Energy","","","",""
"uuid:55fa76ad-7b7a-4586-a66b-bd021170a87b","http://resolver.tudelft.nl/uuid:55fa76ad-7b7a-4586-a66b-bd021170a87b","Multidisciplinary Design and Optimization Framework for Aircraft Box Structures","Van Dijk, R.E.C.; Zhao, X.; Wang, H.; Van Dalen, F.","","2012","Competitive aircraft box structures are a perfect compromise between weight and price. The conceptual design process of these structures is a typical Multidisciplinary Design and Optimization effort, normally conducted by human engineers. The iterative nature of MDO turns development into a long and costly process. Knowledge-Based Engineering can be used to automate this process by capturing relevant design process knowledge, which is then re-used inside a computer application. This research will introduce a parametric, generative box model that has been developed using KBE techniques. The generality and rule-basedness of this model allows for the automatic generation of a wide range of box configurations and variants, thereby enabling a thorough exploration of the design space. Structural and price analyses tools have been coupled to the box model to generate the required discipline-specific performance data. With the product model and coupled analysis tools ready, the goal is to automatically optimize for minimum weight and price without human intervention. The design of Gulfstream 650 rudder is considered as initial use case, the first experiences of which are discussed in this paper.","multidisciplinary design optimization; knowledge-based engineering; knowledge engineering; aircraft box structures; design automation; cost estimation; finite elements modeling","en","conference paper","Royal Aeronautical Society","","","","","","","2013-08-10","Aerospace Engineering","Flight Performance and Propulsion","","","",""
"uuid:93988a21-5be3-4181-b471-b5a941a3641b","http://resolver.tudelft.nl/uuid:93988a21-5be3-4181-b471-b5a941a3641b","Software Language Evolution","Vermolen, S.D.","Van Deursen, A. (promotor)","2012","Software plays a critical role in our daily life. Vast amounts of money are spent on more and more complex systems. All software, regardless if it controls a plane or the game on your phone is never finished. Software changes when it contains bugs or when new functionality is added. This process of change is called software eovlution. Despite what the name suggests, this is in practice a rapid process. Software is described in a software language. Not only software can evolve, also the language it is described in. When a software langauge evolves, the software becomes harder to read, or often times unreadable. To prevent loss of software it needs to evolve along with its language, which is a process known as coupled evolution. Coupled evolution occurs in various domains of computer science, such as in databases, in software models and in software code. This dissertation focuses on different aspects in the context of coupled evolution, such as evolution operators, reconstruction of evolution and the application of coupled evolution.","software; language; evolution; coupled evolution; software engineering; computer science","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Engineering","","","",""
"uuid:a3fbd87e-221f-44d8-b86c-a7a0098ef533","http://resolver.tudelft.nl/uuid:a3fbd87e-221f-44d8-b86c-a7a0098ef533","A simulation based design framework for large scale infrastructure systems design","Huang, Y.; Seck, M.D.; Fumarola, M.","","2012","This paper discusses an enhanced use of Modeling and Simulation (M&S) in the design cycle of large scale infrastructure systems. After a short review of the use of M&S in the current systems design process, we identify some issues in multi-actor design environment. A Simulation Based Design (SBD) framework is proposed to tackle these issues using a multi-methodological approach. The framework is specified with formal description, and the tree-like structuring and refinement of design alternatives are explained. A case of applying the framework to container terminal design is presented and the evaluation is reported.","simulation based design (SBD); systems engineering (SE)","en","conference paper","","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:d0f262d9-ab07-4ae7-839d-782727c534af","http://resolver.tudelft.nl/uuid:d0f262d9-ab07-4ae7-839d-782727c534af","Flowscapes: Infrastructure as landscape, landscape as infrastructure. Graduation Lab Landscape Architecture 2012/2013","Nijhuis, S.; Jauslin, D.; De Vries, C.","","2012","Flowscapes explores infrastructure as a type of landscape and landscape as a type of infrastructure, and is focused on landscape architectonic design of transportation-, green- and water infrastructures. These landscape infrastructures are considered armatures for urban and rural development. With movement and flows at the core, these landscape infrastructures facilitate aesthetic, functional, social and ecological relationships between natural and human systems. Through transdisciplinary design-based case studies at different scale levels Flowscapes seeks for a better understanding of the dynamic between landscape processes and typo-morphological aspects; here interpreted as flowscapes.","landscape architecture; landscape infrastructure; landscape urbanism; green infrastructure; transportation infrastructure; water infrastructure; design research; flowscapes; graduation studio; urbanism; architecture; civil engineering","en","report","Delft University of Technology","","","","","","","2012-09-18","Architecture","Urbanism","","","",""
"uuid:b4fe13a8-7cce-416f-802a-6fd618726d56","http://resolver.tudelft.nl/uuid:b4fe13a8-7cce-416f-802a-6fd618726d56","An internal deletion in MTH1 enables growth on glucose of pyruvate-decarboxylase negative, non-fermentative Saccharomyces cerevisiae","Oud, B.; Flores, C.L.; Gancedo, C.; Zhang, X.; Trueheart, J.; Daran, J.M.; Pronk, J.T.; Van Maris, A.J.A.","","2012","Background Pyruvate-decarboxylase negative (Pdc-) strains of Saccharomyces cerevisiae combine the robustness and high glycolytic capacity of this yeast with the absence of alcoholic fermentation. This makes Pdc-S. cerevisiae an interesting platform for efficient conversion of glucose towards pyruvate-derived products without formation of ethanol as a by-product. However, Pdc- strains cannot grow on high glucose concentrations and require C2-compounds (ethanol or acetate) for growth under conditions with low glucose concentrations, which hitherto has limited application in industry. Results Genetic analysis of a Pdc- strain previously evolved to overcome these deficiencies revealed a 225bp in-frame internal deletion in MTH1, encoding a transcriptional regulator involved in glucose sensing. This internal deletion contains a phosphorylation site required for degradation, thereby hypothetically resulting in increased stability of the protein. Reverse engineering of this alternative MTH1 allele into a non-evolved Pdc- strain enabled growth on 20 g l-1 glucose and 0.3% (v/v) ethanol at a maximum specific growth rate (0.24 h-1) similar to that of the evolved Pdc- strain (0.23 h-1). Furthermore, the reverse engineered Pdc- strain grew on glucose as sole carbon source, albeit at a lower specific growth rate (0.10 h-1) than the evolved strain (0.20 h-1). The observation that overexpression of the wild-type MTH1 allele also restored growth of Pdc-S. cerevisiae on glucose is consistent with the hypothesis that the internal deletion results in decreased degradation of Mth1. Reduced degradation of Mth1 has been shown to result in deregulation of hexose transport. In Pdc- strains, reduced glucose uptake may prevent intracellular accumulation of pyruvate and/or redox problems, while release of glucose repression due to the MTH1 internal deletion may contribute to alleviation of the C2-compound auxotrophy. Conclusions In this study we have discovered and characterised a mutation in MTH1 enabling Pdc- strains to grow on glucose as the sole carbon source. This successful example of reverse engineering not only increases the understanding of the glucose tolerance of evolved Pdc-S. cerevisiae, but also allows introduction of this portable genetic element into various industrial yeast strains, thereby simplifying metabolic engineering strategies.","inverse metabolic engineering; reverse metabolic engineering; whole genome sequencing; glucose tolerance; by-product reduction; MTH1 allele","en","journal article","BioMed Central","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:c8fece0c-06b3-43a9-9a58-d6e96275571e","http://resolver.tudelft.nl/uuid:c8fece0c-06b3-43a9-9a58-d6e96275571e","Using Enterprise Ontology as a basis for Requirements for Cross-Organizationally Usable Applications","Krouwel, M.; Op 't Land, M.","","2012","Developing cross-organizationally usable applications is becoming increasingly important. However, actually re-using business applications has been hindered in practice often by implicit assumptions about organizational and IT implementation. We propose a method to gather requirements for cross- organizationally usable applications that, taking Design and Engineering Methodology for Organizations (DEMO) as starting point, a) is easy to communicate, b) can discern differences between the organizations, and c) has an attractive Return On Modeling Effort (ROME). When testing this method in a large real-life case study, it also appeared to be possible to a) systematically design the `unhappy' flow as well, b) define application architecture principles for supporting organizational flexibility, and c) systematically design screens based on DEMO models, irrespective of internal or external use. Finally the method greatly objectified the discussions between all stakeholders involved.","Enterprise Ontology; requirements engineering; interaction design; cross-organizational; software flexibility; DEMO","en","conference paper","AIS Electronic Library (AISeL)","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:3e6a844d-e90e-4234-b83e-6215846ca652","http://resolver.tudelft.nl/uuid:3e6a844d-e90e-4234-b83e-6215846ca652","La protection du site CURGO - Kabezi -Bujumbura contre les risques hydrologiques dans le bassin de la riviere Nyabage: Etude de formulation d'une operation de conservation","Moeyersons, J.; Trefois, P.","TU Delft","2012","Occasional flows of the river Nyabage cause floods in the river valley, flooding bridges and buildings, amongst others a small hospital of MsF. The flow is a mixture of water and debris and causes severe damage. The report describes the phenomena and the damage in the area. Some proposals for improvements are given","mudflow; river engineering; Burundi; river flood; storm runoff","fr","report","MRAC Tervuren","","","","","","","","","","","","",""
"uuid:efbdabaf-e7ae-4a52-a371-3b27d31761f9","http://resolver.tudelft.nl/uuid:efbdabaf-e7ae-4a52-a371-3b27d31761f9","The trail of six design projects in the Delft bachelor Aerospace Engineering","Kamp, A.","","2012","Tomorrow’s engineers are required to have a good balance between deep working knowledge of engineering sciences and engineering skills. In the Bachelor Aerospace Engineering at TU Delft, students are educated to master these competences so that they are ready to engineer when they graduate. The bachelor curriculum has three mainstreams of about equal study load: Aerospace Design, Aerospace Engineering & Technology, and Basic Engineering Sciences. The Aerospace Design stream is built up semester after semester of a design project and an accompanying design course. The main objectives of the design projects are related to contextual learning, to being a mental organiser for the students, to learning by doing together, and to learning and practicing academic and engineering skills. Over the years of study the design projects increase in complexity and openness, from knowing to application, synthesis and evaluation, from tangible to abstract, from mono- to multidisciplinary, from mostly individual to team work. All projects exploit the factors that promote intrinsic motivation (challenge, curiosity, control, fantasy, competition, cooperation, and recognition). To assure that the intrinsic motivation factors and the semester themes are well addressed, each design project is characterised by a storyline, professional role, client, real-life problem, engineering process, and certain attainment levels of engineering skills. The projects make use of 45 well-equipped student project spaces in a dedicated building and laboratories like wind tunnels, a structures and materials laboratory, a study collection of aircraft and spacecraft parts and subsystems, and a flight simulator. The organisation of the six design projects for 300-440 students per project challenges the resources of the academic staff and the logistics of the project and lab spaces.","project education; project-based learning; experiential learning; aerospace engineering; design education; integrated curriculum","en","conference paper","CDIO","","","","","","","","Aerospace Engineering","Support Aerospace Engineering","","","",""
"uuid:827ee52f-b0cc-40b2-90c0-00e3c57078d1","http://resolver.tudelft.nl/uuid:827ee52f-b0cc-40b2-90c0-00e3c57078d1","Designing socio-technical systems: Structures and processes","Bots, P.W.G.; Van Daalen, C.","","2012","The Systems Engineering, Policy Analysis and Management (SEPAM) MSc curriculum taught at Delft University of Technology focuses on the design of socio-technical systems (STS). We teach our students to structure design activities by considering what we call the TIP aspects: Technical systems, Institutions, and decision-making Processes. Students find TIP design difficult, not only because STS design is complex (this difficulty can be overcome with time and practice), but also because the I and P concepts seem difficult to grasp. Our students struggle with the notion of institution, the lack of a general framework for institutional design, and the fluidity and ambiguity of the concept of a decision-making process in the context of STS design. The objective of this paper is to clarify the TIP elements and to refine the TIP way of thinking. In clarifying the elements, we make a distinction between structure and process. Our premise is that an engineered artifact is a structure that, together with the context in which it is implemented, produces a process that performs the intended function. Our distinction between structure and process shows why the acronym TIP design is somewhat misleading. The T and I refer to structures, while the P refers to processes. This paper adds to the TIP design way of thinking by showing the analogies between technical and institutional structures. We argue that systems thinking/systems design applies to any artifact, be it technical or institutional. The structure-process distinction also allows us to better understand the system life cycle and clarify the concept of a decision-making process. Decision-making processes are important processes in all phases of a system life cycle, and they are themselves shaped by institutional structures which are placed in a context.","systems design; systems engineering; structures in systems engineering; processes in systems engineering; decision making process; institutional design","en","conference paper","","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:b896d33f-c118-4bf1-824a-2d50135f0561","http://resolver.tudelft.nl/uuid:b896d33f-c118-4bf1-824a-2d50135f0561","Game-like Characteristic of Engineering Design","Oruc, S.; Cunningham, S.W.","","2012","Engineering design is conventionally regarded as a mono actor optimization problem and modeled accordingly. Decision making, values and optimality are building blocks of conventional engineering design. However with the advent of decentralized decision making processes, various actors are more likely to be involved in decision making processes in engineering design. As a response in this paper we attempt to claim that engineering design is inherently multi actor and has game-like characteristics. Accordingly a research agenda is put forward.","multi actor systems; engineering design; game theory","en","conference paper","","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:501bbca7-abe4-4834-97aa-a2b61e86c611","http://resolver.tudelft.nl/uuid:501bbca7-abe4-4834-97aa-a2b61e86c611","Interoperability in the networked design infrastructure","Coenders, J.L.","","2012","Interoperability, the ability of different software applications to communicate with each other, is one of the biggest challenges for efficient and effective use of advanced software technology in structural design and engineering. In practice, the problem of interoperability exists very much for the end-user since agreement on common standards does not exist despite the many efforts over the years. This paper discusses an approach to interoperability based on the assumption that one final common standard will probably never exist and that a more practical federated approach needs to be taken. In this paper the author demonstrates the concepts which a new conceptual infrastructure, called NetworkedDesign, provides to address the challenges of interoperability. The infrastructure contains a rich set of concepts for the user to express information through lightweight open objects and logical constructs which can be used as a basis for an ad hoc standard between applications.","interoperability; BIM; Building Information Modelling; Computational Design; NetworkedDesign; structural design; engineering","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:05eca6e2-3139-4b38-98db-eb32f760f895","http://resolver.tudelft.nl/uuid:05eca6e2-3139-4b38-98db-eb32f760f895","StructuralComponents: A software system for conceptual structural design","Van de Weerd, B.; Rolvink, A.; Coenders, J.L.","","2012","Conceptual design is the starting point of the design process. The conceptual design stage comprises the formation of several ideas or design concepts to meet the imposed constraints. StructuralComponents is a software application that attempts to provide the designing engineer with a suitable set of tools for this stage. It facilitates the exploration of the early design space with the proper balance between accuracy and the ability to explore. Using parametric-associative modelling, a structural design concept can be composed of parameters and object relations. Built-in design and analysis knowledge returns immediate output to guide the design process. The major development is a redevelopment of the software architecture as a client-server system in support of emphasising design exploration and a system of design plurality and directed optimisation.","structural engineering; computation; early-stage design tools; parametric-associative modelling; real-time analysis; design argumentation and justification; client-server architecture","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:6d36c4d9-5489-44bb-8223-a7f4bd7693cf","http://resolver.tudelft.nl/uuid:6d36c4d9-5489-44bb-8223-a7f4bd7693cf","Strengthening the Foundations Underlying the Enterprise Engineering Manifesto","Op 't Land, M.; Pombinho, J.","","2012","The discipline of Enterprise Engineering aims for enterprises to operate as a unified and integrated whole. This discipline therefore adopts the mission to develop theories, models, methods and other artifacts for the analysis, design, implementation and governance of enterprises in a theoretically rigorous and practically relevant manner. The Enterprise Engineering Manifesto postulates the dualities of concepts function/construction perspective, black-box/white-box models and subjective/objective as being opposed to each other in one-on-one relationships. Illustrated by the Pizzeria case, it becomes clear (a) that functions can be defined objectively, and (b) that a valuation perspective should be added that truly focuses on the relationship between a system and its stakeholders. These insights can support building stronger bridges between management and organization sciences – traditionally stronger in functional approaches – and information systems science, and computer science – traditionally stronger in constructional approaches.","Enterprise Engineering; Enterprise Engineering Manifesto; Function perspective; Construction perspective; Black-box models; White-box models","en","conference paper","Springer","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:18d90cf6-fddc-48ae-8101-e9eda186a72c","http://resolver.tudelft.nl/uuid:18d90cf6-fddc-48ae-8101-e9eda186a72c","Benefits of Enterprise Ontology in Governing Complex Enterprise Transformations","Op 't Land, M.; Dietz, J.L.G.","","2012","Enterprises increasingly execute complex transformations, such as mergers and splits, chain redesign, sharing and sourcing, and the rationalization of products, processes and applications. Its consequences are seldom sufficiently timely and completely discerned, while this is essential for governing such a transformation. Already in a small example we can see why Enterprise Ontology, as defined in DEMO (Design & Engineering Methodology for Organizations) delivers a clear and valuable instrument for transformation governance. Especially DEMO’s Construction Model, which is the most abstract ontological aspect model, combines high expressiveness with a high Return On Modeling Effort (ROME).","Enterprise Transformation; Governance; Enterprise Ontology; DEMO; Enterprise Engineering; ROME","en","conference paper","Springer","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:1cf2716d-2538-45c9-a383-4a3a887c1323","http://resolver.tudelft.nl/uuid:1cf2716d-2538-45c9-a383-4a3a887c1323","On the formal impossibility of analysing subfunctions as parts of functions in design methodology","Vermaas, P.E.","","2012","In this paper, a proof is given that in design methods, the relation between technical functions and their subfunctions in functional descriptions of technical products cannot be analysed as a formal relation of parthood. This result holds for design methods in which transformations of flows of energy, material and signals are accepted as functions. First, two specific categories of such technical functions are modelled. Second, the composition relation by which ordered sets of these functions define other functions is characterised. Third, it is shown that this composition relation for technical functions does not meet the basic postulates of parthood relations as given by mereology, the theory of parthood. It still may be beneficial to designing to take subfunctions informally as the parts of the functions they compose. Yet, the proof shows that when functional descriptions are formalised for, for instance, the development of automated design reasoning tools or for incorporation in engineering ontologies, the composition relation for technical functions cannot unconditionally be taken as a parthood relation.","technical functions; parthood relations; functional composition; functional decomposition; modelling of functions; engineering ontologies","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:bf89050c-6432-4e40-831c-f14aa7b24c52","http://resolver.tudelft.nl/uuid:bf89050c-6432-4e40-831c-f14aa7b24c52","Metabolic engineering of free-energy (ATP) conserving reactions in Saccharomyces cerevisiae","De Kok, S.","Pronk, J.T. (promotor)","2012","Metabolic engineering – the improvement of cellular activities by manipulation of enzymatic, transport and regulatory functions of the cell – has enabled the industrial production of a wide variety of biological molecules from renewable resources. Microbial production of fuels and chemicals thereby provides an alternative to oil-based production. To compete with petrochemistry, not only the kinetics of product formation, but also the product yield needs to be optimized. Whereas reduction of byproduct formation, modification of redox-cofactor balances and optimization of the stoichiometry of product formation is studies in many laboratories, the ATP yield of product formation is often overlooked, although it is of paramount importance for the product yield that can be obtained. In this thesis, several opportunities for improvement of free-energy (ATP) conservation in the yeast Saccharomyces cerevisiae, a key industrial microorganism, were investigated. For product pathways with excess ATP and biomass formation, a widely applicable strategy (relocating sucrose hydrolysis) was presented to decrease free-energy (ATP) conservation and thereby increase the product yield. On the other hand, the efficiency of free-energy (ATP) conservation was increased by expression of a maltose phosphorylase, which forms the basis for further development of these strategies towards increasing the ATP yield of many industrial target pathways and specifically to potentially enable efficient anaerobic homolactate production with S. cerevisiae.","Saccharomyces cerevisiae; yeast; biotechnology; metabolic engineering; bioethanol; product yield; ATP","en","doctoral thesis","","","","","","","","2012-03-27","Applied Sciences","Biotechnology","","","",""
"uuid:d94a6aef-2745-4722-b052-2b17c92177d9","http://resolver.tudelft.nl/uuid:d94a6aef-2745-4722-b052-2b17c92177d9","Understanding Ajax applications by connecting client and server-side execution traces","Zaidman, A.E.; Matthijssen, N.; Storey, M.A.; Van Deursen, A.","","2012","Ajax-enabled Web applications are a new breed of highly interactive, highly dynamic Web applications. Although Ajax allows developers to create rich Web applications, Ajax applications can be difficult to comprehend and thus to maintain. For this reason, we have created FireDetective, a tool that uses dynamic analysis at both the client (browser) and server-side to facilitate the understanding of Ajax applications. We evaluate FireDetective using (1) a pretest-posttest user study and (2) a field user study. Preliminary evidence shows that the FireDetective tool is an effective aid for Web developers striving to understand Ajax applications.","Ajax; web applications; program comprehension; reverse engineering; dynamic analysis; execution traces","en","journal article","Springer","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Computer Technology","","","",""
"uuid:391597ac-d3da-40e6-9f27-f4b5812cef87","http://resolver.tudelft.nl/uuid:391597ac-d3da-40e6-9f27-f4b5812cef87","Metabolic engineering of ?-oxidation in Penicillium chrysogenum for improved semi-synthetic cephalosporin biosynthesis","Veiga, T.; Gombert, A.K.; Landes, N.; Verhoeven, M.D.; Kiel, J.A.K.W.; Krikken, A.; Nijland, J.G.; Touw, H.; Luttik, M.A.H.; Van der Toorn, J.C.; Driessen, A.J.M.; Bovenberg, R.A.L.; Van den Berg, M.A.; Van der Klei, I.J.; Pronk, J.T.; Daran, J.M.","","2012","Industrial production of semi-synthetic cephalosporins by Penicillium chrysogenum requires supplementation of the growth media with the side-chain precursor adipic acid. In glucose-limited chemostat cultures of P. chrysogenum, up to 88% of the consumed adipic acid was not recovered in cephalosporin-related products, but used as an additional carbon and energy source for growth. This low efficiency of side-chain precursor incorporation provides an economic incentive for studying and engineering the metabolism of adipic acid in P. chrysogenum. Chemostat-based transcriptome analysis in the presence and absence of adipic acid confirmed that adipic acid metabolism in this fungus occurs via ?-oxidation. A set of 52 adipate-responsive genes included six putative genes for acyl-CoA oxidases and dehydrogenases, enzymes responsible for the first step of ?-oxidation. Subcellular localization of the differentially expressed acyl-CoA oxidases and dehydrogenases revealed that the oxidases were exclusively targeted to peroxisomes, while the dehydrogenases were found either in peroxisomes or in mitochondria. Deletion of the genes encoding the peroxisomal acyl-CoA oxidase Pc20g01800 and the mitochondrial acyl-CoA dehydrogenase Pc20g07920 resulted in a 1.6- and 3.7-fold increase in the production of the semi-synthetic cephalosporin intermediate adipoyl-6-APA, respectively. The deletion strains also showed reduced adipate consumption compared to the reference strain, indicating that engineering of the first step of ?-oxidation successfully redirected a larger fraction of adipic acid towards cephalosporin biosynthesis.","Penicillium chrysogenum; ?-lactams; cephalosporins; ?-oxidation; adipic acid; metabolic engineering","en","journal article","Elsevier","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:e0e8fd80-5e06-4d56-bb03-4c4fa3cf4d4c","http://resolver.tudelft.nl/uuid:e0e8fd80-5e06-4d56-bb03-4c4fa3cf4d4c","DEVELOPMENT, IMPLEMENTATION AND TESTING OF A '3D INFORMATION VIEWER' IN SHIPBUILDING","Asmara, A.","Hopman, J.J. (advisor)","2012","","engineering information; 3D CAD; portal; visualization","","conference paper","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:22de373c-669d-4c92-80d1-bb84099962e6","http://resolver.tudelft.nl/uuid:22de373c-669d-4c92-80d1-bb84099962e6","Structural safety performance of Dutch and Spanish engineering companies","Mendez Safont, M (TU Delft Steel & Composite Structures); Terwel, K.C. (TU Delft Steel & Composite Structures)","","2012","","survey; engineering companies; design stage; control procedures","en","conference paper","s.n.","","","","","Author Manuscript","","","","","Steel & Composite Structures","","",""
"uuid:dfc184c0-6869-4d7c-9236-b2b8c1f4cd65","http://resolver.tudelft.nl/uuid:dfc184c0-6869-4d7c-9236-b2b8c1f4cd65","Cognitive engineering of a military multi-modal memory restructuring system","Brinkman, W.P.; Vermetten, E.; Van den Steen, M.M.; Neerincx, M.A.","","2011","Several methods have been proposed to treat combat veterans with posttraumatic stress disorder (PTSD). Still, a recent review reports on high drop-out and non response rates. This has motivated work into the design of a software application to support and to increase the appeal of traditional face-to-face trauma-focused psychotherapy. The research followed a situated cognitive engineering approach, which included a domain analysis, scenarios and claims analysis based on experts reviews (N=10), user evaluations, and a case study. This resulted in the identification of nine core application functions: (1) provide a flexible way of storytelling, (2) provide a structured way of storytelling, (3) prevent losing track of changed and added events, (4) ensure patient trust, (5) ensure usage for therapists with different backgrounds, (6) ensuring awareness of treatment, (7) provide a personal approach, (8) prevent unexpected exposure to emotional material, (9) and ensure appealing and motivating approach throughout the therapy. These functions formed the basis for the design of a military multi-modal memory restructuring (Military - 3MR) system, which focuses on restructuring and relearning of past events. The system allows patient and therapist to visualise past events using personal photos, narrative text, online geographical maps, webcam snapshots, and patient created 3D virtual worlds. Results of the usability evaluation (N=18) suggests key design features such as the time line, content manage, and the 3D world editor, of an acceptable perceived usability level. Results of a storytelling experiment (N=18) between telling an autobiographical story with or without Military-3MR system, found that with the system, time referencing and event description were more precise, and a smaller time period in the story was covered. In the case study, the veteran suffering from combat-related PTSD was pleased with the system and felt encouraged talking about his past events.","PTSD, trauma-focused psychotherapy, memory, multimedia, restructuring, reappraisal, 3MR, 4MR, cognitive engineering, mental health system.","en","journal article","Virtual Reality Medical Institute","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Mediamatics","","","",""
"uuid:55b86a6e-56a9-4da1-96f1-afdd564baca4","http://resolver.tudelft.nl/uuid:55b86a6e-56a9-4da1-96f1-afdd564baca4","The structural strength of glass: Hidden damage","Veer, F.A.; Rodichev, Y.M.","","2011","We discuss “hidden damage” of glass by the rolling process, which results in heterogeneous distribution of microcracks on the edge surface of glass element, which are the fracture source deteriorating glass element strength. It is shown that removal of this damage on the edges of glass elements increases the engineering strength of float glass significantly. Using the “hidden damage” approach, we provide strength determination for the weakest specimens that is statistically relevant and is based on a reliable engineering parameter.","glass; rolling process; hidden damage; engineering parameter; microcracks","en","journal article","Springer","","","","","","","","Architecture","Building Technology","","","",""
"uuid:e5e51cdd-a0ed-48a0-b488-61b170d7e8af","http://resolver.tudelft.nl/uuid:e5e51cdd-a0ed-48a0-b488-61b170d7e8af","Cognitive engineering in mental health computing","Brinkman, W.P.","","2011","Computer applications in support of mental health care and rehabilitation are becoming more widely used. They include technologies such as virtual reality, electronic diaries, multimedia, brain computing and computer games. Research in this area is emerging, and focussing on a variety of issues, such as clinical effectiveness of a computer supported intervention, usability of a system, human values that are affected by a technological intervention, actual use, acceptance, and accessibility of these systems. To classify and to understand the objectives of the work presented in this special issue the mental health computing research model is presented. This descriptive model identified four research categories: (1) technology elements, (2) technology intervention, (3) clinical effect, and (4) field use. Each category has its own focus, methods and set of researchers.","cognitive engineering, mental health computing, research model","en","journal article","Virtual Reality Medical Institute","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Mediamatics","","","",""
"uuid:36dd7f23-b1fa-4a58-806a-8da5f303e291","http://resolver.tudelft.nl/uuid:36dd7f23-b1fa-4a58-806a-8da5f303e291","An Industrial Evaluation of Technological Support for Overhearing Conversations in Global Software Engineering","Dullemond, K.; Van Gameren, B.; Van Solingen, R.","","2011","Software engineering is by nature a highly collaborative activity. However, collaborating effectively in Global Software Engineering, in which team members are geographically, temporally and/or socio-culturally separated from each other, is more difficult. In a traditional co-located setting, one of the most important communication patterns is a (face-to-face) conversation. Technological solutions to have conversations in a distributed setting are commonly used, however overhearing conversations of others is not explicitly supported. In this paper we report on the evaluation of supporting overhearing conversations with technology in a distributed industrial setting. To do this we deployed a tool we developed with which it is possible to overhear Instant Messaging conversations in an international software development company. Based on this evaluation we report lessons learned and conclude with the most important findings of this study.","Computer-supported collaborative work; Knowledge-based software engineering; Empirical software engineering; Tools and environments","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:cb762718-99fa-4acb-b796-33907a3649c9","http://resolver.tudelft.nl/uuid:cb762718-99fa-4acb-b796-33907a3649c9","Benefits of ecological engineering practices","Brüll, A.; Van Bohemen, H.; Costanza, R.; Mitsch, W.J.","Van den Boomen, R. (contributor); Chaudhuri, N. (contributor); Heeb, J. (contributor); Jenssen, P. (contributor); Kalin, M. (contributor); Schönborn, A. (contributor)","2011","With the intention to further promote the field of ecological engineering and the solutions it provides, a workshop on “Benefits of Ecological Engineering Practices” was held 3 Dec 2009. It was conducted by the International Ecological Engineering Society in Paris at the conference “Ecological Engineering: from Concepts to Application” organized by the Ecological Engineering Applications Group GAIE. This paper presents the results of the workshop related to three key questions: (1) what are the benefits of ecological engineering practices to human and ecosystem well-being, (2) which concepts are used or useful to identify, reference, and measure the benefits of ecological engineering practices, and (3) how and to whom shall benefits of ecological engineering practices be promoted. While benefits of ecological engineering practices are diverse, general conclusions can be derived to facilitate communication. Identifying benefits requires valuation frameworks reaching beyond the scope of ecology and engineering. A distinction between human and ecosystem well-being in this regard may not be easy or useful, but instead humans embedded in ecosystems should be addressed as a whole. The concepts of resource efficiency, ecosystem services, ecosystem health, and multifunctional land use could serve as suitable references to frame ecological engineering benefits, as well as referring to international political goals such as biodiversity protection, climate change mitigation and poverty reduction. Sector and application specific criteria of good practice could be worked out. Regional, area specific reference systems for sustainable development could provide comparative advantages for ecologically engineered solutions. Besides people with high decision making power and people with high motivation for change are good target groups to be addressed.","benefits; ecological engineering; reference systems","en","journal article","Elsevier","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:8de70820-c91c-4abc-bd31-6559c8550b41","http://resolver.tudelft.nl/uuid:8de70820-c91c-4abc-bd31-6559c8550b41","A training approach for the transition of repeatable collaboration processes to practitioners","Kolfschoten, G.L.; De Vreede, G.J.; Pietron, L.R.","","2011","This paper presents a training approach to support the deployment of collaboration process support according to the Collaboration Engineering approach. In Collaboration Engineering, practitioners in an organization are trained to facilitate a specific collaborative work practice on a recurring basis. To transfer the complex skill set of a facilitator to support the practitioner in guiding a specific collaboration process design, we propose a detailed training approach based on the logic of Cognitive Load Theory. The training approach focuses on transferring knowledge and skills in the form of thinkLets, i.e. repeatable facilitation techniques. Furthermore, the training contains a process simulation to practice challenges in collaboration support. The training approach was positively evaluated using a questionnaire instrument in a case study.","facilitation; collaboration engineering; transfer; cognitive load theory; GSS; training","en","journal article","Springer-Verlag","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:6e22696c-9075-41d2-9aef-99d8636857e6","http://resolver.tudelft.nl/uuid:6e22696c-9075-41d2-9aef-99d8636857e6","A Ten-Step Design Method for Simulation Games in Logistics Management","Fumarola, M.; Van Staalduinen, J.P.; Verbraeck, A.","","2011","Simulation games have often been found useful as a method of inquiry to gain insight in complex system behavior and as aids for design, engineering simulation and visualization, and education. Designing simulation games are the result of creative thinking and planning, but often not the result of a rigorously applied design method. Design methods can be used to structure the creative process. The specific types of games we chose for studying design methods are simulation games focused on information-intensive domains, of which logistics management is an example. Our new design method takes into account the information intensiveness of the domain. The design method incorporates enterprise information management, simulation model design, and instructional design. The design method we propose uses ten steps in designing a simulation game: the first five for making a conceptual design and the final five for using the conceptual design as a basis for the simulation game. Iterative cycles are added to improve intermediate results. This paper discusses the design method and presents two different case studies. The first case study helped in developing the design method, while the second case study served for assessment and improvement.","design method; game design; gaming simulation; engineering simulation and visualization; instructional design","en","journal article","American Society of Mechanical Engineers (ASME)","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:10e25404-4b8e-443b-9f16-5e6e5c2a7444","http://resolver.tudelft.nl/uuid:10e25404-4b8e-443b-9f16-5e6e5c2a7444","Characterising Combustion in Diesel Engines: Using parameterised finite stage cylinder process models","Ding, Y.","Stapersma, D. (promotor); Grimmelius, H.T. (promotor)","2011","Characterising combustion of diesel engines is not only necessary when researching the instantaneous combustion phenomena but also when investigating the change of the combustion process under variable engine operating conditions. An effective way to achieve this goal is to parameterize the combustion process using a finite combustion stage cylinder process model and then the parameters can be modeled to give a global description of diesel engine combustion. The main objective of this thesis is getting information how to calculate (simulate) the parameters defining the finite stage cylinder process model using both theoretical and experimental methods. The latter is essential but also complicated.","diesel engine; combustion; heat release; Seiliger process","en","doctoral thesis","VSSD","","","","","","","","Mechanical, Maritime and Materials Engineering","Department of Maritime and Transport Technology","","","",""
"uuid:75ab3a78-5f07-4f18-ba0e-7f813a867ad1","http://resolver.tudelft.nl/uuid:75ab3a78-5f07-4f18-ba0e-7f813a867ad1","Using and Developing Role Plays in Teaching Aimed at Preparing for Social Responsibility","Doorn, N.; Kroesen, J.O.","","2011","In this paper, we discuss the use of role plays in ethics education for engineering students. After presenting a rough taxonomy of different objectives, we illustrate how role plays can be used to broaden students’ perspectives. We do this on the basis of our experiences with a newly developed role play about a Dutch political controversy concerning pig transport. The role play is special in that the discussion is about setting up an institutional framework for responsible action that goes beyond individual action. In that sense, the role play serves a double purpose. It not only aims at teaching students to become aware of the different dimensions in decision making, it also encourages students to think about what such an institutional framework for responsible action might possibly look like.","role play; ethics teaching; engineering; institutional context; organizational constraints; macro-ethics; responsible action; institutional framework","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:c3b17264-a7ed-4f6d-aca7-88c34f2f6958","http://resolver.tudelft.nl/uuid:c3b17264-a7ed-4f6d-aca7-88c34f2f6958","Building Blocks for Language Workbenches","Kats, L.C.L.","Van Deursen, A. (promotor)","2011","This dissertation presents research on techniques, methods, and tool support for domain-specific language engineering. Domain-specific language engineering is the discipline of designing, developing, and maintaining domain-specific programming languages. The focus of this thesis is the architecture of language workbenches their underlying technologies. Language workbenches are tools that make language engineering more efficient by providing an integrated development environment for language engineering tasks. In particular, we introduce the Spoofax language workbench, and describe its techniques for high-level, portable language definitions, language composition, interactive support for defining languages, and language testing. Our research focuses on three main themes: applying domain-specific languages for declarative specification of languages and IDEs; supporting declarative syntax definition for generating a parser-based, interactive development environment; and providing interactive meta-tooling support, exploring the application of modern IDE technology to DSL engineering.","language workbenches; domain-specific languages; language engineering; parsers; integrated development environments","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:6be7582c-63b1-477e-b836-87430bcfb43f","http://resolver.tudelft.nl/uuid:6be7582c-63b1-477e-b836-87430bcfb43f","A Packing Approach for the Early Stage Design of Service Vessels","Van Oers, B.J.","Stapersma, D. (promotor); Hopman, J.J. (promotor)","2011","Naval architects often say that every ship is a compromise between many conflicting requirements. This widely-held belief immediately raises the question as to what kind of ship and, therefore, what kind of compromise, would suit the ship owner’s interest best. The approach presented in this thesis aims to improve the early stage design process of service vessels by helping the naval architect to generate and explore a large and diverse set of three-dimensional ship designs. In turn, this set enables the thorough investigation of a wide range of different compromises before settling upon a well-founded –and a more competitive- ship design that reflects the most promising compromise and, as such, will be deemed desirable by its owner. The approach has four key features. Firstly, it uses a novel parametric ship description (based on `packing problems’) that can handle large and concurrent changes to the entire three-dimensional ship design, i.e., hull, superstructure, decks, bulkheads and the arrangement of systems in the ship can all change without human interaction. Secondly, it uses a search algorithm to generate a large and diverse set of ship designs that reflect a wide range of different compromises. Thirdly, the naval architect considers all feasible designs to gain insight in conflicting characteristics before selecting the most promising ship designs in a transparent manner. The selection can be based on objective and constraint values, as well as on the naval architect’s own engineering judgement. Fourthly, the naval architect takes all selection decisions to help instil the crucial sense of ownership for the ship designs that result from the selection process. This novel design approach has been applied successfully to design two types of service vessels: deep water drillships and frigates. It proved able to establish the design impact of variations in payload and performance requirements. Moreover, the resulting set of designs was subsequently used to illustrate how the naval architect can identify and select designs that excel at particular performances, such as sea-keeping. In summary, the approach is expected to improve the naval architect’s ability to identify promising ship designs early on, which should lead to the design of more competitive service vessels.","acceptance; arrangement; compromise decision; configuration; drillship; engineering judgement; feasible ship design; incomplete set of objectives; layout; naval architecture; optimisation algorithm; packing problem; parametric ship description; selection problem; service vessel; ship design; too optimal; trade-off; transparency; warship","en","doctoral thesis","VSSD","","","","","","","2011-11-23","Mechanical, Maritime and Materials Engineering","Marine & Transport Technology","","","",""
"uuid:d64b8ff8-8d68-4eea-a320-73148e9f1b15","http://resolver.tudelft.nl/uuid:d64b8ff8-8d68-4eea-a320-73148e9f1b15","Deterioration Mechanisms and Durability of Sprayed Concrete for Rock Support in Tunnels","Hagelia, P.","Van Breugel, K. (promotor)","2011","Steel fibre reinforced sprayed concretes used for rock support in tunnels are subjected to variable and complex exposure conditions. Structurally weakened concretes (5 to 35 years old) were investigated with respect to deterioration mechanisms, sources of aggressive agents and related engineering aspects. The evidence was based on field characterisation/sampling, concrete petrography, chemical microanalysis, X-ray diffraction, water chemistry and stable isotope systematics. The Alum shale and subsea tunnel environments represent the most severe ground water conditions in Norway, whilst ion poor waters had much lesser effects on concrete durability. Alkali-Aggregate Reaction was unimportant. Historically, Alum Shale has caused severe and rapid cement paste degradation, previously interpreted to be due to ettringite and sulfuric acid attack. However, examination of historical test samples within this study proved this was due to Thaumasite Sulfate Attack (TSA). TSA was closely associated with decalcification of the cement paste matrix and internal detrimental carbonation, such as Popcorn Calcite Deposition (PCD). Two novel reaction mechanisms were found: a) development of high crystallisation pressures during thaumasite deposition and b) TSA was most efficient after partial or complete decalcification of the cement paste matrix: Thaumasite had formed at the expense of remaining amorphous silica and secondary calcite (PCD). Sulfuric acid caused outer leaching, making way for deep effects of aggressive ions. Modern sprayed concrete made with Sulfate Resisting Portland Cement and silica fume had suffered similar but less rapid degradation, leading to local spalling with destructive fibre corrosion after < 13 years. Anhydrite in Alum Shale was the main source of sulfate, whilst pyrite and pyrrhotite oxidation was less important than previously claimed. A multiproxy study suggested that thaumasite sulfate originated from partial reduction of anhydrite sulfate and formation of H2S within the rock mass and subsequent re-oxidation to sulfuric acid near tunnel space. This process was likely assisted by sulfate reducing bacteria and Acidithiobacilli, respectively. Thaumasite carbon was derived from calcite in the Alum Shale and atmospheric CO2, whilst the shale organic carbon was inert. A novel composite degradation mechanism was discovered in subsea tunnels, leading to partial to complete breakdown of the cement paste matrix and destructive steel fibre corrosion. Such degradation was evident after < 4 years of exposure, and the rate of disintegration varied from < 0.5-10 mm/year. This was due to: a) acidification caused by redox reactions within layered Mn-Fe biofilms (Leptothrix sp. and Gallionella sp.) and b) infiltration of saline ground waters and abiotic transformation of the cement paste due to decalcification, magnesium attack, TSA and PCD. At advanced stages gypsum deposits, with crystalline carbon derived from biofilm material, had formed on the outer concrete surface. Important consequences for engineering were derived. The concrete standard EN 206-1 has important shortcomings, because it does not involve classification relevant to biodegradation, hydrogeological environment and effects of evaporation. It was established that sprayed concretes subjected to a hydraulic gradient were more degraded than similar concrete under static conditions. Moreover, H and O isotopic evidence showed that evaporation of tunnel water due to tunnel drought can cause a 100 % to 1000 % relative increase in ionic concentrations. Consequences for service life, maintenance/repair and rules and recommendations were discussed. The challenge of future studies into durability of sprayed concrete for rock support is to fully understand the interaction of biotic and abiotic deterioration mechanisms and the complex impact of water and rock mass instability.","Sprayed concrete; Tunnels; Deterioration mechanisms; Sources of aggressives; Black shale; Subsea; Biofilms; Thaumasite attack; Popcorn calcite; Magnesium attack; Hydraulic gradient; EN 206-1; Engineering aspects","en","doctoral thesis","Norwegian Public Roads Administration","","","","","","","","Civil Engineering and Geosciences","Materials & Environment","","","",""
"uuid:a783e581-bc7a-4efa-adcb-7e9201840367","http://resolver.tudelft.nl/uuid:a783e581-bc7a-4efa-adcb-7e9201840367","Managing project complexity: A study into adapting early project phases to improve project performance in large engineering projects","Bosch-Rekveldt, M.G.C.","Verbraeck, A. (promotor); Bakker, H.L.M. (promotor)","2011","Engineering projects become increasingly more complex and project complexity is assumed to be one of the causes for projects being delivered late and over budget. However, what this project complexity actually comprised of was unclear. To improve the overall project performance, this study focuses on identifying the potential causes of complexity in projects. Moreover, it is investigated how the early project phase could be adapted to the complexity of the project. The research is performed with companies of the NAP network, which brings together companies from the entire value chain in the Dutch process industry. The study is structured in four phases and included exploratory case studies, a quantitative survey, explanatory case studies and an evaluative survey. By combining qualitative and quantitative work, this study is an example of successfully applying a mixed methods approach in project management research. The main results of this study are the TOE (Technical, Organizational, External) framework to grasp project complexity and recommendations on managing project complexity in the early project phase. To improve project performance the role of integrated teams (joint owner / contractor teams) as well as thorough application of risk management is shown to be crucial.","Complexity; Project Management; Front-end development; Project Performance; Large Engineering Projects; Process Industry","en","doctoral thesis","Delft Centre for Project Management","","","","","","","2011-11-15","Technology, Policy and Management","TSE","","","",""
"uuid:82b3123d-e094-43de-b7c9-e9d3755fd90e","http://resolver.tudelft.nl/uuid:82b3123d-e094-43de-b7c9-e9d3755fd90e","From adaptive to high-performance structures","Teuffel, P.","","2011","Multiple design aspects influence the building performance such as architectural criteria, various environmental impacts and user behaviour. Specific examples are sun, wind, temperatures, function, occupancy, socio-cultural aspects and other contextual aspects and needs. Even though these aspects are acknowledged to be variable, conventional buildings are conceived to provide one design solution, represented in a static configuration. Ongoing research includes several of the above mentioned environmental design drivers, amongst others wind, earthquakes, daylight, interior and exterior climate as well as user requirements. In this paper two of these aspects shall be considered and discussed in more detail; namely wind and earthquakes, which are manipulated with shape morphing elements within the building envelope and / or active structural elements. Finally an outlook will be presented how the introduction of the idea of adaptive systems will have impact on the future of structural engineering.","adaptive systems; structural control; wind engineering; seismic design","en","conference paper","Korean Society of Steel Construction (KSSC)","","","","","","","","Architecture","Building Technology","","","",""
"uuid:ed039724-870d-401a-b2db-d27d3759257e","http://resolver.tudelft.nl/uuid:ed039724-870d-401a-b2db-d27d3759257e","Simple, Complex, Innovative: Design Education at Civil Engineering","Van Nederveen, G.A.; Soons, F.A.M.; Suddle, S.I.; De Ridder, H.","","2011","In faculties such as Civil Engineering, design is a not a core activity. Core activities at Civil Engineering are structural engineering, structural analysis, mechanics, fluid dynamics, etc. Design education has a relatively small share in the curriculum, compared to faculties such as Industrial Design or Architecture. Against this background, our group has developed a design track within the Civil Engineering curriculum. This design track starts in the Bachelor phase with design fundamentals, continues with methods and skills for dealing with complexity, and culminates in the Master phase with innovative design approaches based on concepts such as living systems, parametric design, product development and life cycle thinking.","design education; civil engineering; integrated design","en","conference paper","TU Delft & IASDR","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:e42638c8-6a2a-4929-917b-20529f6fbd9f","http://resolver.tudelft.nl/uuid:e42638c8-6a2a-4929-917b-20529f6fbd9f","Integrated Language Definition Testing: Enabling Test-Driven Language Development","Kats, L.C.L.; Vermaas, R.; Visser, E.","","2011","The reliability of compilers, interpreters, and development environments for programming languages is essential for effective software development and maintenance. They are often tested only as an afterthought. Languages with a smaller scope, such as domain-specific languages, often remain untested. General-purpose testing techniques and test case generation methods fall short in providing a low-threshold solution for test-driven language development. In this paper we introduce the notion of a language-parametric testing language (LPTL) that provides a reusable, generic basis for declaratively specifying language definition tests. We integrate the syntax, semantics, and editor services of a language under test into the LPTL for writing test inputs. This paper describes the design of an LPTL and the tool support provided for it, shows use cases using examples, and describes our implementation in the form of the Spoofax testing language. This paper is a pre-print of: Lennart C. L. Kats, Rob Vermaas, Eelco Visser. Integrated Language Definition Testing. Enabling Test-Driven Language Development. In Kathleen Fisher, editor, Proceedings of the 26th Annual ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages, and Applications (OOPSLA 2011), ACM, 2010.","Testing; Test-Driven Development; Language Engineering; Grammarware; Language Workbench; Domain-Specific Language; Language Embedding; Compilers; Parsers","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:d83bc5f2-17b9-4b77-b846-ecbbf388bb7d","http://resolver.tudelft.nl/uuid:d83bc5f2-17b9-4b77-b846-ecbbf388bb7d","Moveable flood barriers in the Rhine-Meuse estuary","Rijcken, T.; Kok, M.","","2011","It is possible to reduce flood risk in estuaries without having to drastically modify the river banks by levees or to block shipping routes and ecological flows by dams. ‘Storm surge barriers’ close off a river mouth at times of high sea water levels, but keep the river open during calmer times. ‘Moveable river flood barriers’ direct a river towards less urbanised parts of the delta. It is likely that with climate change and continuing economic growth more of these barriers will be built worldwide. The influential Dutch state commission the ‘Delta Commission’ has adopted an idea by Delft University of Technology to flood-proof the Dutch Rhine-Meuse delta by a number of existing and new moveable barriers. These will direct high water flows in desired directions, particularly at times when a storm at sea coincides with high river discharges. This would create a historically complex system of flood defenses, thus needing thorough modelling and more detailed design to evaluate benefits and costs. This paper will compare a number of alternatives as follows: locate the various barriers on different locations, see where additional river widenings would be possible, calculate the remaining required levee modifications (dictated by Dutch national flood law) as a function of sea level rise, determine the effects on urbanisation of the river banks, on shipping, and if possible also on ecological flows. This comparison will in this paper not lead to the ‘best configuration’, but to valuable insight in the system. It appears that improving the high water prediction errors and the location, failure probability, operating regimes and architecture of the barriers will increase benefits and reduce costs of the entire flood protection system. This paper follows from a multidisciplinary, explorative and practically-oriented research project (11 different researchers and consultants) conducted under the Dutch ‘Hotspot Rotterdam - Knowledge for Climate’ programme in 2010.","flood risk; flood works; river engineering; hydraulic engineering; urbanism","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:58b2acc2-e97e-4c2c-b40f-c05c49b5d1fd","http://resolver.tudelft.nl/uuid:58b2acc2-e97e-4c2c-b40f-c05c49b5d1fd","Cost Optimizations in Runtime Testing and Diagnosis","Gonzalez Sanchez, A.","Van Gemund, A.J.C. (promotor)","2011","Software testing and diagnosis (debugging) is a time-consuming but rather important task for improving software reliability. It is therefore necessary to devise an appropriate verification strategy that not only achieves this reliability goal, but also does this at a minimum cost. Since exhaustive testing is hardly ever possible, testing typically aims at detecting the presence of faults, by trying to produce a failure (the external manifestation of a fault). Once failures have been detected, the faults that produced them have to be localized. Unfortunately for developers, it has recently been shown that effective fault detection and effective fault localization are contradictory goals. In particular, it has been shown that focusing exclusively on fault detection has a detrimental effect on fault localization, canceling the savings in testing cost by an increase in diagnostic cost. In this thesis we explore the causes for this cost increase, and propose a shift in the goal of testing, focusing on techniques that achieve much better fault localization performance, while maintaining fault detection performance.","software engineering; testing; diagnosis; debugging; runtime testing","en","doctoral thesis","","","","","","","","2011-09-19","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:5bf6aec3-4662-4211-b1d2-145ca934ca41","http://resolver.tudelft.nl/uuid:5bf6aec3-4662-4211-b1d2-145ca934ca41","Development of a Methodology to Support Design of Complex Aircraft Wings","Cooper, C.A.","Benedictus, R. (promotor); Van Tooren, M.J.L. (promotor)","2011","The design of complex systems in today’s aerospace domain requires a balance between the ever-increasing complexity of the supporting technology and the drive to develop those systems in a compressed timeframe. The performance knowledge of a preliminary design must shift backwards in the lifecycle in order to exploit that knowledge when there is still freedom in the design. Design of aerospace structures with fiber metal laminates (FML) represents one such area where the increased design freedom comes at a cost of increased design complexity. The potential benefits of FML technology, however, demand a solution to this design challenge. FMLs require a different approach to design and manufacturing that so far has been only moderately explored for possible automation. In order to support design of an FML wing, a tailored design methodology and prototyping tools are needed. The quantitative systems engineering field of knowledge based engineering (KBE) provides a solution. A KBE approach, leveraging parametric, geometry-based modeling and expert FML manufacturability knowledge, can work within a design framework to automate many of the non-creative activities of the FML designer, such as initial layup design and manufacturability rule application. This research seeks to frame the FML wing design process, develop critical KBE design modules tailored for FML knowledge, and illustrate their utility in the balance of aerospace structure weight and cost.","fiber metal laminates; knowledge based engineering; systems engineering","en","doctoral thesis","","","","","","","","","Aerospace Engineering","Aerospace Materials and Manufacturing (AMM); Aerospace Structures & Design Methodologies (AS&DM)","","","",""
"uuid:4e5d68db-8ac4-41b5-9e6f-3f4b515721db","http://resolver.tudelft.nl/uuid:4e5d68db-8ac4-41b5-9e6f-3f4b515721db","Exploring Normalized Systems Potential for Dutch MoD’s Agility: A Proof of Concept on Flexibility, Time-to-market, Productivity and Quality","Op 't Land, M.; Krouwel, M.R.; Van Dipten, E.G.; Verelst, J.","","2011","Both the Command and Control Support Centre (C2SC) of the Dutch Ministry of Defense, and Capgemini are constantly exploring better ways of building and maintaining information systems which ef- fectively support strategy and operations of an enterprise. In a Proof of Concept conducted in March and April 2011, together with University of Antwerp, they evaluated the possibilities of the Normalized Systems approach for building information systems. In 50 man days not only a system was built that would normally be built in 100-150 man days, also a major technology change had taken place (in week 2 Cocoon and EJB2 were replaced by Struts and EJB3) and changes in the (data) mod- els were instantly processed, even in the last week of development. With these results, Normalized Systems is considered a key enabler in rapid enterprise transformation. Moreover, because Normalized Systems makes it possible to have a continuous link from enterprise (process) modeling to software development and a short feedback loop from system develop- ment back to enterprise modeling, it is also considered a key enabler for agile enterprise engineering. This will also enable shortening the typical cycles of enterprise governance.","DEMO; Design & Engineering Methodology for Organizations; Normalized Systems; Agile Enterprise Engineering; Ministry of Defense; SCRUM; case study","en","conference paper","Springer","","","","","","","","Technology, Policy and Management","Multi-Actor Systems","","","",""
"uuid:7736b3d2-e36b-4fcf-8257-12f650038a37","http://resolver.tudelft.nl/uuid:7736b3d2-e36b-4fcf-8257-12f650038a37","Mind the evaluation gap: Reviewing the assessment of architectural research in the Netherlands","Van der Hoeven, F.D.","","2011","How the assessment of the scientific quality and societal relevance of Dutch architectural research has evolved to bridge the evaluation gap between design and engineering.","architecture; assessment; design; engineering","en","journal article","Cambridge University Press","","","","","","","2012-08-08","Architecture","Urbanism","","","",""
"uuid:00be55c3-b780-4b2f-8b5c-c1786d29e269","http://resolver.tudelft.nl/uuid:00be55c3-b780-4b2f-8b5c-c1786d29e269","How the Dutch plan to stay dry over the next Century","Stive, M.J.F.; Fresco, L.O.; Kabat, P.; Parmet, B.W.A.H.; Veerman, C.P.","","2011","Over two-thirds of the Netherlands’ economy and half its population is below sea level. The Dutch government recently set out far-reaching recommendations on how to keep the country flood-proof over the next century given the likelihood of rising sea levels and river flows. This paper explains the recommendations, which are based on a gradual upgrading of safety standards in the light of economic growth and group casualty risk, together with triggers provided by debates and data on climate change. It concludes that protection is feasible both technically and economically, costing up to 3 billion a year, and that the approach could be useful for other low-lying areas.","flood defence; coastal engineering; deltacommissie; river engineering","en","journal article","ICE Institution of Civil Engineers","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:467617ff-fc83-4f1e-92a5-04728ff916f2","http://resolver.tudelft.nl/uuid:467617ff-fc83-4f1e-92a5-04728ff916f2","Delft Aerospace engineering integrated curriculum","Kamp, A.","","2011","The complex multidisciplinary problems and challenges in our society require deep problem solvers in science, management and engineering who are also capable of interacting with and understanding specialists from a wide range of disciplines and functional areas. Industry refers to these people as T-shaped professionals. The T-shaped professional model has been the reference for the bachelor and master curricula in Aerospace Engineering at Delft University of Technology. The bachelor provides the broad academic background in the domain of aerospace engineering. The life cycle of the engineering process and contextual storylines of famous persons in aviation, aeronautics or space form the cement and thread for the themes of the bachelor curriculum. The bachelor develops the academic intellectual skills and attitudes to analyse, apply, synthesize, and design, and prepares for the master. The master programme aims to develop the basic competences acquired in the bachelor to a higher level in terms of knowledge, critical reflection, making judgements and working independently. While “engineering and design” is the central theme of the bachelor, “research” is the theme of the master. This curricular framework gives the bachelor and master an own profile and identity. They use state-of-the-art content that is interwoven with thematic design projects and trainings for personal and system building skills, using international standard text books, up-to-date teaching methods, excellent facilities, with a focus on the aircraft and spacecraft throughout the programmes. Excellence programmes are available for the top 5 percent students in both bachelor and master. In these honours classes self-regulated students define their personal learning objectives and levels to be attained. Their key concept is that of open-ended learning and autonomy. In the bachelor the excellence programme substitutes design projects in the regular curriculum by one ambitious and compelling project with a high societal relevance and visibility. In the master it is a halfyear add-on programme about taking the lead in the creation and operation of new products, systems or processes, and developing awareness and understanding of the importance and strategic impact of research and technological developments on society.","integrated curriculum; T-shaped professional; aerospace; engineering education","en","conference paper","CDIO","","","","","","","","Aerospace Engineering","Support Aerospace Engineering","","","",""
"uuid:bf930678-d676-4c4f-85c1-c7188b6718f7","http://resolver.tudelft.nl/uuid:bf930678-d676-4c4f-85c1-c7188b6718f7","NetworkedDesign: Next generation infrastructure for computational design","Coenders, J.L.","Wagemans, L.A.G. (promotor); Vambersky, J.N.J.A. (promotor)","2011","During the design and engineering process of buildings and structures an enormous amount of data and information is produced. Logic, knowledge and experience is employed during this process by the designers and engineers to finally come to the design result. Because this information can not be fully recorded by software, a huge amount of information and a potential resource for further investigation in the design process is lost. One reason among others being that the current systems are not able to support the subprocesses in the design process and hold the information stack consisting of data, information, knowledge, etc. If a computational infrastructure would be available which would be able to hold and record the stack produced, an important opportunity exists for learning from this information and producing better designs,manage buildings better, etc. Furthermore, advanced computational technology has a number of additional advantages which at the moment cannot be fully benefited from, such as better coordinated and more optimised design, more understanding of complex behaviour, information management and digital manufacturing. This is because the current life cycle of the building or structure cannot be completely followed through in computational systems and therefore gaps in the essential steps of the design and engineering process appear and therefore loss of information. Again, an infrastructure which would be able to support development of tools, applications, frameworks and systems and which would be able to carry data across processes and tools potentially could improve this situation. This research project envisions this infrastructure as a conceptual base for development of the tools and systems of the future. The term ‘infrastructure’ has been chosen due to the aimed similarity with other infrastructures which acted as a platform technology for a variety of innovations, such as the mobile network infrastructure and glass-fibre network infrastructure. When developing such an infrastructure an important barrier arises which is the fact that it is not trivial to define what the users (designers and engineers) require from such an infrastructure to be able to work closely with it during the design process. An computational and conceptual infrastructure is a very abstract concept for end-users. End-users often are not aware of all technological possibilities and usually can only define immediate short term requirements but not long term development requirements or map out complex abstract concepts. To resolve this issue application of a custom methodology has been proposed and used for the studies in which conceptshave been derived from observations in practice through a process called Empathic Design (Leonard and Rayport, 1997) (note that observations include any data derived observing practice, so also include active derivation of observations, such as discussions, or even observed critique of available systems and paradigms active in practice) and are linked to technological concepts which have been derived from various technological sources of development. Finally, this results in a first step toward a computational design theory which sets out the conceptual direction for development and future research. The process of abstraction of theory from observations through concepts and conceptualisation has been based on the research methodology Grounded Theory (Glaser and Strauss, 1967). To develop the theory a study has been performed into structural design and engineering, its key values and its key characteristics in relationship to their pitfalls for computation. Furthermore, technological concepts have been studied and reported on in this dissertation which provide inspiration and direction to be linked to the concepts from the design and engineering domain. A number of existing technologies has been studied to identify strengths and shortcomings to establish further reaching concepts. The first attempt to meet the requirements established in the computational design theory was made by making use of parametric and associative design, which appears in software applications such as GenerativeComponents (Aish, 2005) and Grasshopper (McNeel, 2008). This paradigm has a various features closely matching the concepts of design, such as the ability to follow through change, the ability to define and process logic and decomposition. However, closer study showed that modifications and extensions had to be made to make it applicable in structural design and engineering. These modifications and extensions are discussed in this dissertation and various published papers. However, finally, a set of concepts remained which required fundamental modification of the paradigm. Therefore, a new infrastructure has been proposed under the name ‘NetworkedDesign’ which includes new concepts unavailable in previous studied paradigms, such as multi-directionality, solving by choice, meta-process and meta-knowledge, as well as a large number of previously existing concepts in a novel combination of a single infrastructure. A first implementation of this infrastructure in the form of a prototype demonstration design system has been used to demonstrate the concepts of the infrastructure in a variety of situations. This infrastructure opens new opportunities for the application of computation in practice as well as new areas of research previously largely unrelated to the building industry such as collective intelligence, computational intelligence and embedded design intelligence. In the practice of the application of computation in structural design and engineering this infrastructure will open new opportunities for new design tools, such as StructuralComponents (Rolvink et al., 2010), as well as partial resolution of the issues with interoperability.","computational design; design; NetworkedDesign; structural engineering; structural design; IT; ICT; ICKT","en","doctoral thesis","VSSD","","","","","","","","Civil Engineering and Geosciences","BEMNext Laboratory","","","",""
"uuid:e5e2fe97-04ed-414d-a9c7-4045cf6eea28","http://resolver.tudelft.nl/uuid:e5e2fe97-04ed-414d-a9c7-4045cf6eea28","Leading indicators for civil engineering","Nippala, E.; Tienhaara, P.","","2011","The opening and globalisation of the market presents additional information needs. In the closed market, planning information gave a clear enough picture of the civil engineering situation. The same source of information is still used when looking at the situation in the open market. Companies and central government have often viewed the economic cycle of civil engineering somewhat differently because there is different kind information available. The goal of this research has been to distinguish from the information flood those pieces of information that best predict future development to help procurements and operative planning of companies. The market structure has become more complicated and more indicators are needed than before. The lack of quantitative data has to be compensated by expert opinions. The leading indicator candidates are the change of GDP, the outsize projects, the finance situation of clients and the expert opinion.","leading indicators; civil engineering; market change","en","conference paper","","","","","","","","","","","","","",""
"uuid:26d5c229-c770-4080-82af-b12ae97a2a0b","http://resolver.tudelft.nl/uuid:26d5c229-c770-4080-82af-b12ae97a2a0b","Multidisciplinary design and optimization of a plastic injection mold using an integrated design and engineering environment","Van Dijk, R.E.C.; dIppolito, R.; Tosi, G.; La Rocca, G.","","2011","In order to remain competitive with respect to low-cost overseas markets, domestic moldmakers will have to increase the productivity of their engineers and maintain high quality standard, while dealing with the problem of an aging workforce. To increase the competitiveness of the European automotive industry, the concept of and Integrated Design and Engineering Environment (IDEE) has been developed within the 6th framework European project Pegasus - Integrated engineering processing & materials technologies for the European sector. The IDEE consists of a distributed set of software applications able to accelerate the design process of plastic injection molds by means of process automation and multidisciplinary optimization techniques. The IDEE combines into a single user-friendly platform different technologies ranging from Knowledge Management (KM) and Knowledge-Based Engineering (KBE) to Process Integration and Automation (PI&A). Central to the IDEE framework is a KBE application, which consists of a fully parametric rule-based mold product model. On the basis of the geometry of the plastic part to be molded and other (user) inputs, the KBE application can automatically produce different mold configurations and variants. In this way, product knowledge is leveraged to automate the repetitive and therefore time-consuming CAD modelling activities typically encountered in industry. Next to the mold geometry, the KBE application is able to generate different reports that serve as input to in-house developed or commercially-of-the-shelf CAE applications, like Autodesk® Moldflow® Synergy. The resulting software framework enables the simulation and analysis of the injection molding process, from which important performance characteristics can be retrieved. Other disciplinary applications are used to assess the cost and the environmental impact of the molding process and tooling. All the IDEE software applications are provided as web services on remote servers according to the Software as a Service (SaaS) paradigm. Noesis’s Optimus software has been used to link them into a seamless framework, control their execution and support all data exchange in an automated fashion over the internet. The scope of this paper is to describe the architecture and main functionalities of the IDEE and provide the results of studies performed on representative plastic parts for the automotive industry. It is demonstrated how the IDEE can enable multidisciplinary optimization of the injection molding process and find solutions that best balance manufacturing performance and product quality. By means of the IDEE many concepts and customized variants can be quickly generated and evaluated in terms of hours or days instead of weeks or months, thereby supporting a more efficient development of innovative and complex parts. The reliability of the evaluation is enhanced by the early use of computer-based simulations in the design process, and the success rate of the overall component increased because of the more disciplines included in the evaluation (tooling design, material processing, cost, environmental impact). The IDEE can help the designer to virtually prototype and analyze the product and, eventually, support the “first-time-right” design principle.","multidisciplinary design and optimization; knowledge-based engineering; knowledge management; plastic injection mold design","en","conference paper","NAFEMS ltd","","","","","","","","Aerospace Engineering","Aerospace Design, Integration & Operations","","","",""
"uuid:6d7338a1-87ef-4cd1-94b3-47dcdd47ec16","http://resolver.tudelft.nl/uuid:6d7338a1-87ef-4cd1-94b3-47dcdd47ec16","Moral responsibility in R&D networks: A procedural approach to distributing responsibilities","Doorn, N.","Van den Hoven, M.J. (promotor); Van der Poel, I.R. (promotor)","2011","The introduction of new technologies can be accompanied by risks and unforeseen side-effects, often with high impact. If no-one is responsible for addressing these risks and side-effects, the implementation of technologies might result in harmful consequences for society. It is therefore desirable that the prevention of these negative aspects of technology is already taken into account explicitly in Research and Development (R&D). However, even if most people would agree that the people working in R&D have a professional responsibility to address these issues, it is not clear who exactly should address it and how. Is it the the responsibility of the fundamental or applied researchers working in the laboratory or should it be delegated to the technology producers at the end of the chain? One of the problems with professional responsibility is that people have different views on responsibility and the question under what conditions one is responsible. This may ultimately lead to gaps in the distribution of responsibilities because people may expect someone else to assume the remaining responsibilities. This thesis discusses an alternative approach to distributing responsibilities. Rather than developing one substantive conception of the responsibility of professionals, a procedural approach for distributing responsibilities is developed. The idea behind this procedural approach is that people may agree on the procedure for distributing the responsibilities, even if they do not have the same substantive view on responsibility. The model is illustrated with a case study on a technological project concerning the development of an in-house monitoring system based on ambient technology.","research & development (R&D); moral responsibility; engineering ethics; Professional ethics; wide reflective equilibrium; ambient intelligence technology; procedural fairness; John Rawls","en","doctoral thesis","3TU.Centre for Ethics and Technology","","","","","","","2011-05-11","Technology, Policy and Management","Values and Technology - Philosophy","","","",""
"uuid:eddf2885-33a6-4639-9325-591a61eec40e","http://resolver.tudelft.nl/uuid:eddf2885-33a6-4639-9325-591a61eec40e","Channel and shoal development in a short tidal embayment: An idealized model study","Ter Brake, M.C.; Schuttelaars, H.M.","","2011","In many tidal embayments, complex patterns of channels and shoals are observed. To gain a better understanding of these features, an idealized model, that describes the interaction of water motion, sediment transport and bed evolution in a semi-enclosed, rectangular basin, is developed and analysed. To explain the initial formation of channels and shoals, two-dimensional perturbations superposed on a laterally uniform equilibrium bottom are studied. These perturbations evolve due to convergences of various residual suspended sediment fluxes: a diffusive flux, a flux related to the bed topography, an advective flux resulting from internally generated overtides and an advective flux due to externally prescribed overtides. For most combinations of these fluxes, perturbations start to grow if the bottom friction is strong enough. Their growth is mainly a result of convergences of diffusive and topographically induced sediment fluxes. Advective contributions due to internally generated overtides enhance this growth. If only diffusive sediment fluxes are considered, the underlying equilibrium is always unstable. This can be traced back to the depth dependence of the deposition parameter. Contrary to the results of previous idealized models, the channels and shoals always initiate in the shallow, landward areas. This is explained by the enhanced generation (compared to that in previous models) of frictional torques in shallow regions. The resulting initial channel–shoal formation compares well with results found in complex numerical model studies. The instability mechanism and the location of the initial formation of bottom patterns do not change qualitatively when varying parameters. Changes are mainly related to differences in the underlying equilibrium profile due to parameter variations.","coastal engineering; morphological instability; pattern formation","en","journal article","Cambridge University Press","","","","","","","2012-05-03","Electrical Engineering, Mathematics and Computer Science","Delft Institute of Applied Mathematics","","","",""
"uuid:e1235b05-5859-4b8e-b5c6-24670b273533","http://resolver.tudelft.nl/uuid:e1235b05-5859-4b8e-b5c6-24670b273533","Realizing Service Migration in Industry - Lessons Learned","Nasr, K.A.; Gross, H.G.; Van Deursen, A.","","2011","In this paper, we present two descriptive case studies covering the re-engineering and further evolution of adopting service oriented architecture (SOA) in industry. The first case was carried out for a company in the transport sector with an application portfolio of over 700 systems. The second case study was conducted for an organization in the public sector. The goal of both case studies is to identify possible benefits and drawbacks of realizing SOA in large organizations in order to obtain a better perspective on the real, rather than the assumed, benefits of SOA in practice. We describe how the two cases were developed and carried out, and discuss the experiences gained and lessons learned from adopting SOA in the two organizations. Based on these findings, we propose several directions for further research. Accepted for publication in the Journal of Software Maintenance and Evolution: Research and Practice, 2011, Wiley-Blackwell","service oriented architecture; re-engineering; case study; system integration","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:c10c2b98-c218-429a-b48b-7904650df041","http://resolver.tudelft.nl/uuid:c10c2b98-c218-429a-b48b-7904650df041","Engineering and the Problem of Moral Overload","Van den Hoven, J.; Lokhorst, G.J.; Van de Poel, I.","","2011","When thinking about ethics, technology is often only mentioned as the source of our problems, not as a potential solution to our moral dilemmas. When thinking about technology, ethics is often only mentioned as a constraint on developments, not as a source and spring of innovation. In this paper, we argue that ethics can be the source of technological development rather than just a constraint and technological progress can create moral progress rather than just moral problems. We show this by an analysis of how technology can contribute to the solution of so-called moral overload or moral dilemmas. Such dilemmas typically create a moral residue that is the basis of a second-order principle that tells us to reshape the world so that we can meet all our moral obligations. We can do so, among other things, through guided technological innovation.","moral overload; engineering; technological progress","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:cb9b1243-81a2-4be1-b52d-98b1f2ac0035","http://resolver.tudelft.nl/uuid:cb9b1243-81a2-4be1-b52d-98b1f2ac0035","The Problem of Many Hands: Climate Change as an Example","Van de Poel, I.; Fahlquist, J.N.; Doorn, N.; Zwart, S.; Royakkers, L.","","2011","In some situations in which undesirable collective effects occur, it is very hard, if not impossible, to hold any individual reasonably responsible. Such a situation may be referred to as the problem of many hands. In this paper we investigate how the problem of many hands can best be understood and why, and when, it exactly constitutes a problem. After analyzing climate change as an example, we propose to define the problem of many hands as the occurrence of a gap in the distribution of responsibility that may be considered morally problematic. Whether a gap is morally problematic, we suggest, depends on the reasons why responsibility is distributed. This, in turn, depends, at least in part, on the sense of responsibility employed, a main distinction being that between backward-looking and forward-looking responsibility.","responsibility; technology engineering; problem of many hands; collective responsibility; climate change","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:7ec8be66-621e-452b-a7a4-915f65465d3e","http://resolver.tudelft.nl/uuid:7ec8be66-621e-452b-a7a4-915f65465d3e","Functional characterization of the oxaloacetase encoding gene and elimination of oxalate formation in the β-lactam producer Penicillium chrysogenum","Daran, J.M.; Pronk, J.T.; Driessen, A.J.M.; Nijland, J.G.; Lamboo, F.; Puig-Martinez, M.; Veiga, T.; Gombert, A.K.","","2011","Penicillium chrysogenum is widely used as an industrial antibiotic producer, in particular in the synthesis of ß-lactam antibiotics such as penicillins and cephalosporins. In industrial processes, oxalic acid formation leads to reduced product yields. Moreover, precipitation of calcium oxalate complicates product recovery. We observed oxalate production in glucose-limited chemostat cultures of P. chrysogenum grown with or without addition of adipic acid, side-chain of the cephalosporin precursor adipoyl-6-aminopenicillinic acid (ad-6-APA). Oxalate accounted for up to 5% of the consumed carbon source. In filamentous fungi, oxaloacetate hydrolase (OAH; EC3.7.1.1) is generally responsible for oxalate production. The P. chrysogenum genome harbours four orthologs of the A. niger oahA gene. Chemostat-based transcriptome analyses revealed a significant correlation between extracellular oxalate titers and expression level of the genes Pc18g05100 and Pc22g24830. To assess their possible involvement in oxalate production, both genes were cloned in Saccharomyces cerevisiae, yeast that does not produce oxalate. Only the expression of Pc22g24830 led to production of oxalic acid in S. cerevisiae. Subsequent deletion of Pc22g28430 in P. chrysogenum led to complete elimination of oxalate production, whilst improving yields of the cephalosporin precursor ad-6-APA.","oxaloacetate hydrolase; chemostat-based transcriptomics; metabolic engineering; Penicillium chrysogenum; β-lactam; oxalate; OA-Fund TU Delft","en","journal article","Elsevier","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:b2423a0a-6d5b-4149-9e1e-95f0396f6f74","http://resolver.tudelft.nl/uuid:b2423a0a-6d5b-4149-9e1e-95f0396f6f74","Functional Decomposition: On Rationality and Incommensurability in Engineering","Van Eck, D.","Kroes, P.A. (promotor)","2011","The concept of technical function is a key concept to describe technical artifacts and artifacts-to-be-designed. Engineers often give such descriptions in terms of functional decomposition models, which represent relationships between functions and sets of other (sub) functions. Despite the importance of the concept of function there is no consensus among engineers about its meaning. Models of functional decomposition are likewise conceptually divergent. Although this conceptual diversity hampers information exchange between engineers, they accept and maintain it. Engineers do not, by and large, engage in a focused debate to establish commonly shared functional conceptualizations. This contrasts with science where both debates on the adequacy of key conceptualizations and convergence toward shared conceptualizations are common. This book investigates the side-by-side usage of different functional decomposition models in engineering. It explains this phenomenon by applying and extending the analysis of theory choice in terms of methodological incommensurability to engineering functional decomposition, rather than to science. This analysis shows that engineers’ usage of competing functional decomposition models is rational from a practical point of view. This book furthermore investigates the communication problems that the side-by-side usage of different models engenders and presents a strategy that supports the exchange and re-use of functional information between engineers.","philosophy of engineering; functional decomposition; incommensurability; practical rationality","en","doctoral thesis","","","","","","","","2011-04-21","Technology, Policy and Management","Philosophy","","","",""
"uuid:45ed17b3-4743-4adc-bd65-65dd203e4a09","http://resolver.tudelft.nl/uuid:45ed17b3-4743-4adc-bd65-65dd203e4a09","Knowledge based engineering techniques to support aircraft design and optimization","La Rocca, G.","Van Tooren, M.J.L. (promotor)","2011","Since the 1960s, the demand for air transportation has doubled every 15 years, resilient to every oil crises and international events. However, the current capability of the air transport management system, the demand of increasingly growing levels of quality, comfort, safety and security, and, above all, an environmental sensitivity as high as never before, seem to constrain any further growth. The Advisory Council for Aeronautical Research in Europe (ACARE), similarly to NASA in the United States, has indicated a set of challenging objectives and devised a roadmap to help the aerospace industry stepping into a new age of sustainable growth. However, major technological advances will not be possible without significant improvements to the current design methodology. In this regard, the present research work aims at the development of new design methods and tools that are able to sustain the evolutionary improvement of current aircraft designs, as well as to support the investigation of novel aircraft configurations. To be successful, these design methods and tools must be able to facilitate the aircraft development process as it is currently carried across large and distributed supply chains. Besides, they must account for the increasing scarcity of intellectual resources and the consequent need to increase engineers’ productivity and freeing time for innovation. The Multidisciplinary Design Optimization (MDO) approach appears to be the most promising design methodology in the field of aircraft design, both to improve the performance of traditional aircraft configurations and to support the development of novel concepts. However, a number of technical and non-technical barriers have prevented full exploitation of the MDO approach and, so far, limited its industrial application to detail design cases. To this purpose, the concept of Design and Engineering Engine (DEE) has been developed at the Faculty of Aerospace Engineering in Delft, which is a modular, loosely integrated design system able to support distributed multidisciplinary analysis optimization by automating as far as possible the repetitive and non creative activities that hamper the design and analysis process. One of the DEE technology enabler is the Multi Model Generator (MMG), which actually represents the main outcome of this research work. The Multi-Model Generator (MMG) is a Knowledge Based Engineering (KBE) application developed with the twofold intent of 1) providing designers with a parametric modeling environment to define generative models of conventional and novel aircraft configurations and 2) feeding various analysis tools with dedicated aircraft model abstractions, as required for the verification of the generated design. To meet these objectives, two types of functional blocks have been developed, which constitute the main ingredients of the MMG: the High Level Primitives (HLPs) and the Capability Modules (CMs). Four High Level Primitives have been defined, namely Wing-part, Fuselage-part, Engine and Connection-element. These can be figured out as a suite of advanced LEGO blocks that designers can manipulate to assemble the geometry (external surfaces and structural layout) of the aircraft concept they have in mind. Each HLP has been programmed as a class using the object-oriented programming language of the employed KBE system. This has allowed capturing the design rules that give the HLPs the capability to automatically adapt their own shape and topology, or to trigger events as a reaction of input changes. By means of the editable MMG input file, designers can assign different values to the attributes of each HLP class and call for multiple HLPs instantiations. In this way, both conventional and novel aircraft configurations can be automatically generated and then stretched/morphed into an infinite amount of variants. During the conceptual design phase, designers “see” the aircraft as an assembly of basic solutions to fulfill functionalities, such as generate lift and accommodate payload, rather than an assembly of points, curves, surfaces and solid features. The capabilities to support the designer’ functional thinking and capture knowledge in terms of design rules, have yielded the MMG primitives the “high level” connotation, in contrast with the “low level” primitives of conventional CAD. Once the model of the given aircraft is available, the preparation for the verification phase starts, which requires the set up of the various discipline abstractions (or views) that must be fed to the analysis tools. In the traditional design process, the preparation of these disciplinary models is acknowledged to be lengthy and repetitive, particularly when high fidelity analysis tools are involved. Up to 80% of the overall design process can be wasted just for these preprocessing activities. However, it has been observed that 1) independently from the aircraft configuration at hand, the same analysis tools and preprocessing methods are generally used by specialists; 2) large part of the preprocessing activities is rule-based and require a large deal of geometry manipulation, which actually represent the strengths of KBE technology. To support this phase of the design process, a set of Capability Modules (CM) has been developed to capture the “model preprocessing knowledge” of discipline experts and reuse it to automate the generation of models for a broad range of low and high fidelity analysis tools, both proprietary and commercial off the shelf. The implemented approach has enabled the use of high fidelity analysis tools, such as FEM and CFD, already in the early stages of the design process, which not only increases the level of confidence in the designed product, but provides essential means for the study of innovative aircraft configurations, where semi-empirical and statistics based methods fail and first principle analysis is the only way to go. Due to its ability to be accessed in remote, via web connections, and operated in batch, the MMG also demonstrated to be a valuable asset to support MDO processes across distributed design frameworks. The capability of the MMG has been demonstrated by means of several example applications and two relevant study cases addressed in this work. The first case concerns with the European project MOB, on distributed multidisciplinary design optimization of blended wing body aircraft configurations. The second deals with a MDO system developed in collaboration with Airbus to redesign the vertical tail of an existing passenger aircraft. A side objective of this work was to improve the dissemination of KBE technology, which is still a relatively young discipline that has not yet found the deserved level of attention and understanding, both in the world of industry and academia. To this scope, an extensive and original investigation on the Artificial Intelligence roots of KBE is provided and its object oriented paradigm thoroughly discussed. A best practice section to the development of KBE applications is included as well.","Knowledge based engineering; aircraft design; Multidisciplinary design optimization; Multi Model Generator; High Level Primitive; Capability Module","en","doctoral thesis","","","","","","","","","Aerospace Engineering","Aerospace Design, Integration & Operations","","","",""
"uuid:78c577c9-6f25-4db6-8413-de5e0e2d3ed6","http://resolver.tudelft.nl/uuid:78c577c9-6f25-4db6-8413-de5e0e2d3ed6","Metabolic engineering of Saccharomyces cerevisiae for C4-dicarboxylic acid production","Zelle, R.M.","Pronk, J.T. (promotor)","2011","Biotechnological production of chemicals from renewable feedstocks offers a sustainable alternative to petrochemistry. Understanding of the biology of microorganisms and plants is increasing at an unprecedented rate and tools with which these organisms can be engineered for industrial application are becoming ever more powerful. However, biotechnological production processes that are cost-competitive with petrochemistry still have to be developed for many types of chemicals. In this thesis, the ability of Saccharomyces cerevisiae (baker’s yeast) to produce C4-dicarboxylic acids (fumarate, malate and succinate) is investigated. These acids, currently produced from oil in relatively small quantities and mainly applied for human consumption, have interesting properties for roles as commodity platform chemicals. First, S. cerevisiae was metabolically engineered for malate production via a pyruvate carboxylase-dependent pathway. While titers of nearly 60 g per liter were achieved, the fermentation process required oxygen, a significant drawback. Therefore, the second part of the research focused on improving process energetics by using phospho-enol-pyruvate carboxykinase or malic enzyme as alternative carboxylating enzymes. Interestingly, it was found that either enzyme could replace the anaplerotic function of pyruvate carboxylase, which offers the perspective of anaerobic and more efficient production of C4-acids with S. cerevisiae.","biotechnology; saccharomyces cerevisiae; metabolism; metabolic engineering; yeast; organic acids","en","doctoral thesis","","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:377d2731-7994-447a-8f82-14ab6f1f4125","http://resolver.tudelft.nl/uuid:377d2731-7994-447a-8f82-14ab6f1f4125","Modifiers for quality assurance in group facilitation","Kolfschoten, G.L.; Grünbacher, P.; Briggs, R.O.","","2011","A key task of a professional facilitator is to assure the quality of the knowledge products created through collaborative effort. To manage the quality of the knowledge a group generates, facilitators attend to, judge, and question the quality of the contributions a group makes, the decisions it makes and the commitments its members make toward achieving the group’s goals. When facilitators or group members detect deficiencies in ideas, decisions, agreements, or artifacts, facilitators may need to intervene to support the group in improving the quality of their output, without disrupting the flow of the group process. In this paper we present a framework for quality assessment and a toolbox with flexible interventions that can be added to a collaborative process on the fly as soon as quality deficiencies are detected. The toolbox is a set of conditional adjustment interventions that a facilitator can add to other facilitation techniques so as to guard the quality of the group’s intellectual products. The toolbox can also be used as a starting point for designing intelligent agents that support the automatic detection of quality deficiencies.","facilitation; quality assurance; thinkLets; collaboration engineering; modifiers","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:c225db4b-d7b1-4857-8432-7a89b0e85c76","http://resolver.tudelft.nl/uuid:c225db4b-d7b1-4857-8432-7a89b0e85c76","The design stance and its artefacts","Vermaas, P.E.; Carrara, M.; Borgo, S.; Garbacz, P.","","2011","In this paper we disambiguate the design stance as proposed by Daniel C. Dennett, focusing on its application to technical artefacts. Analysing Dennett’s work and developing his approach towards interpreting entities, we show that there are two ways of spelling out the design stance, one that presuppose also adopting Dennett’s intentional stance for describing a designing agent, and a second that does not. We argue against taking one of these ways as giving the correct formulation of the design stance in Dennett’s approach, but propose to replace Dennett’s original design stance by two design stances: an intentional designer stance that incorporates the intentional stance, and a teleological design stance that does not. Our arguments focus on descriptions of technical artefacts: drawing on research in engineering, cognitive psychology and archaeology we show that both design stances are used for describing technical artefacts. A first consequence of this disambiguation is that a design stance, in terms of interpretative assumptions and in terms of the pragmatic considerations for adopting it, stops to be a stance that comes hierarchically between the physical stance and the intentional stance. A second consequence is that a new distinction can be made between types of entities in Dennett’s approach. We call entities to which the intentional designer stance is applied tools and entities to which the teleological design stance is applied instruments, leading to a differentiated understanding of, in particular, technical artefacts.","design stance; technical artefact; Daniel C. Dennett; engineering; cognitive psychology; archaeology; classes of artefacts; instrument; tool","en","journal article","Springer Verlag","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:4bc07d00-4455-4c38-b97e-5a06e77d9ce7","http://resolver.tudelft.nl/uuid:4bc07d00-4455-4c38-b97e-5a06e77d9ce7","Performance of Engineered Cementitious Composites for Concrete Repairs","Zhou, J.","Van Breugel, K. (promotor); Ye, G. (promotor)","2011","Background and goals of this thesis The concrete repair, rehabilitation and retrofitting industry grows rapidly, driven by deterioration of, damage to and defects in concrete structures. However, it is well known that to achieve durable concrete repairs is very difficult. The failure of concrete repairs causes high economical, social and environmental impacts. The main reason of failures is that most repair materials and the repair-substrate interface cannot withstand the high stresses induced by differential shrinkage. Failures, therefore, manifest themselves by cracking in the repair material and debonding of the repair material from the substrate. The first goal of this thesis is to develop a “green” Engineered Cementitious Composites (ECC) and to demonstrate the good performance of this “green” ECC. The second goal is to develop a numerical tool, which can simulate the bond strength between the repair material and the concrete substrate, to assist engineers in designing a durable concrete repair with good bond. Research methodology The stresses induced by differential shrinkage in repair systems were investigated analytically. The analytical study has shown that differential shrinkage induces lower stresses in the ECC repair system, compared with conventional repair materials. For this reason, ECC was chosen as a repair material in this research. Conventional ECC contains a larger amount of cement than concrete, typically two or three times larger. The high cement content leads a high shrinkage, high costs and poor sustainability performance. A “green” ECC with low cement content was developed by partially substituting Portland cement with limestone powder and blast furnace slag. The surface cracking and interface delamination of the “green” ECC repair system were investigated experimentally. In order to demonstrate the potential of ECC to prolong the service life of the repair structures, the rapid chloride migration (RCM) test was used to investigate the chloride penetration profile in the cracked ECC repair system. In order to investigate the microstructure development and the bond mechanism in concrete repairs, the experimental techniques, including non-evaporable water test, MIP, ESEM and bond strength test, were applied. In order to quantitatively study the microstructure development and the bond strength in the repair system, the cement hydration model HYMOSTRUC was extended. The moisture transport between the two materials (the repair material and the concrete substrate) and the cement hydration process of the repair material was taken into account in this numerical tool. Summary of the results of this thesis The analytical study has revealed that the shrinkage of the repair material, the size of the repair system, the Young’s modulus and the roughness of the substrate influence the distribution and magnitude of the differential shrinkage-induced stresses. It was also found that differential shrinkage induces lower stresses in the ECC repair system compared with conventional repair materials. This thesis demonstrates the feasibility of designing a “green” ECC with limestone powder and BFS. This mixture has a Portland cement content as low as 15% (by weight), which is about half of the standard ECC. At 28 days, the “green” ECC shows high tensile strain capacity of 3.3% and a moderate compressive strength of 38. Subjected to a differential shrinkage, the “green” ECC repair system shows a larger number of cracks and smaller crack width (40 ?m) than a conventional repair material, e.g. a fiber-reinforced polymer-modified repair mortar. Even though ECC cracks, it can carry more tensile load and accommodate larger tensile strain. Due to the smaller crack width, the maximum chloride penetration depth in ECC is much smaller than that in a conventional repair material. The service life prediction using the DuraCrete model revealed that, in order to achieve the same service life, the ECC repair system needs smaller cover thickness than the conventional repair material. It is also found that the bond strength is a crucial factor influencing the performance of the ECC repair system. To enhance the bond strength, therefore, is very important to realize durable ECC repairs. The moisture transport shows a significant influence on the cement hydration and microstructure development of the repair material. Before setting of the repair material, the concrete substrate absorbs water from the repair material. This causes a reduction of the w/c ratio in the repair material. The reduction of the w/c ratio affects the degree of hydration and the porosity of the repair material as well as the bond strength. After setting of the repair material, the cement hydration works as a “motor” and generates the driving force for the moisture exchange in the two materials, while water acts as “fuel”, which is consumed by the “motor” and influences the efficiency of the “motor”. The numerical study has shown that the microstructure development of the repair material and the bond strength are influenced by many parameters, i.e. the porosity and water content of the concrete substrate, the w/c ratio of the repair material, and the thickness of the repair material and the concrete substrate. The correlation between the bond strength and the microstructure of the repair material was observed numerically. Due to the “wall effect”, the cement particles have a loose packing at the interface, and the w/c ratio locally increases. The increased w/c ratio results in a porous interfacial zone. The tensile strength of the interface is, in case of a smooth surface of the substrate, lower than that of the repair material. As a result, under a tensile load, the specimen with a smooth surface of the substrate fails at the interface. The surface roughness does not influence the moisture exchange and the cement hydration process. However, it has a significant influence on the bond strength. As the surface roughness increases, the contact area between the repair material and the concrete substrate increases as well. The increased contact area contributes to the bonding of the interface. As a result, the bond strength increases, and the failure changes from debonding at the interface to cracking of the repair material. Based on the above fact, ECC, with its high ductility and tight crack width, is a good choice.","concrete repairs; Engineered Cementitious Composites; bond strength","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Design and Construction","","","",""
"uuid:98f76195-3e2a-4d00-aa44-5949b0c946d9","http://resolver.tudelft.nl/uuid:98f76195-3e2a-4d00-aa44-5949b0c946d9","Physical Modelling for Systems and Control: Lecture Notes Course sc4032, 2009-2010","Bosgra, O.H.","","2010","In these notes the formulation of models is aimed at obtaining a description of the dynamic behaviour of processes under transient conditions. This implies that we will formulate the equations of motion of the process variables that describe the evolution of the process as a function of time. Our models will formulate the process dynamics in a form as required for the understanding of process operations such as startup and shutdown, or for studying the transitions from one operating condition to another one as, e.g., required by grade changes in a production plant or by changes in the composition of the feedstock. Process dynamic models also are of great importance for providing control engineers with qualitative and quantitative descriptions of the transient behaviour of processes that are to be used in model based control system design.","systems and control; process engineering; physical modelling; process dynamics; transient behaviour","en","book","TU Delft","","","","","","","","Mechanical, Maritime and Materials Engineering","Delft Center for Systems and Control (DCSC)","","","",""
"uuid:6b1414ee-8e09-4c97-8d67-cc96af129ae7","http://resolver.tudelft.nl/uuid:6b1414ee-8e09-4c97-8d67-cc96af129ae7","Heavy Plasma NAPALM Propulsion Simulation Code","Lörincz, I.; Rugescu, R.D.; Kohlenberg, J.; Prathaban, M.","","2010","The NAPALM project addresses a new and revolutionary space propulsion system, able to deliver a very high specific impulse through a new working fluid and accelerator principle for the electric plasma thruster. The new motor will impressively exceed, by between ten and sixty percent, the vacuum specific impulse of all existing electric and thermo-electric rocket engines. The accomplishment is based on a new working medium, comprised of relatively high-mass gasified nanoparticles that will be accelerated up to very high kinetic energies. While all current electric thrusters are only able to deliver up to 15.000s specific impulse, the new thruster is expected to deliver between 18.000 and over 30.000s specific impulse. This extraordinary property will increase in the equal amount the deliverable ideal velocity during an interplanetary mission. This increased exit velocity conveys into an equal amount of propellant saving, for any equivalent mission performance. Within the range of low thrust levels, a particularly efficient application of the new thruster is in the attitude control of orbital spacecraft, which will save large amounts of propellant, in comparison to the chemical attitude control units and to other existing electrical thrusters. Additionally, the NAPALM thruster will deliver an absolute thrust of more than 0.1 Newton for every mass flow rate of 1 milligram/second and thus an absolute vacuum thrust exceeding 18 Newton is expected.","plasma engine; electric propulsion; nano-materials","en","conference paper","International Research Alliance for Science and Technology","","","","","","","","Aerospace Engineering","Space Engineering","","","",""
"uuid:bcfa879d-0014-41d3-8038-93a1ec24e315","http://resolver.tudelft.nl/uuid:bcfa879d-0014-41d3-8038-93a1ec24e315","Quality assessment in the design and engineering disciplines, a systematic framework","Dijkgraaf, R.","Van der Hoeven, F.D. (contributor)","2010","Op verzoek van de drie technische universiteiten in Nederland heeft de KNAW geadviseerd over de wijze waarop zij de kwaliteit van ontwerpende en construerende disciplines adequaat kunnen beoordelen. Het rapport pleit voor differentiatie in de manier van beoordelen van verschillende vakgebieden. Het advies schetst een systeem met twee beoordelingscriteria: wetenschappelijke kwaliteit en maatschappelijke relevantie. De discipline-afhankelijke invulling zit in de indicatoren die gebruikt worden om te bepalen hoe goed een onderzoeksvoorstel, persoon of onderzoeksgroep aan deze twee criteria voldoet.","KNAW; TWINS; design; engineering","en","report","Royal Netherlands Academy of Arts and Sciences","","","","","","","","Architecture","","","","",""
"uuid:e86ece18-54ad-4535-a243-70dc3f6cc2a5","http://resolver.tudelft.nl/uuid:e86ece18-54ad-4535-a243-70dc3f6cc2a5","Theoretical performance of countercurrent reactors for production of enantiopure compounds","Saric, M.; Van der Wielen, L.A.M.; Straathof, A.J.J.","","2010","Irreversible reactions are being applied in enzymatic kinetic resolution to obtain enantiomerically pure compounds from racemic mixtures. Using model calculations for situations without mass transfer limitation, we show that reversible reactions might also be useful for enzymatic kinetic resolution, provided that countercurrent systems are used rather than batch or cocurrent systems. The required reaction time or enzyme amount in a countercurrent system is much lower than in an analogous cocurrent system or its batch equivalent. More importantly, often the calculated yield and enantiomeric excess are better in countercurrent systems. Racemization can also be favorably used in countercurrent systems. Consequently, to achieve with a reversible reaction a particular enantiomeric excess and yield, a countercurrent system needs less dilution or activated co-reactant and less enantioselective enzyme than a cocurrent system.","countercurrent system; mathematical modeling; enzyme; simulation; reaction engineering; multiphase reactors","en","journal article","Elsevier","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""
"uuid:94fd1664-9fdc-4868-b2c6-d977c0fbc2e2","http://resolver.tudelft.nl/uuid:94fd1664-9fdc-4868-b2c6-d977c0fbc2e2","Conceptual Design Automation: Abstraction complexity reduction by feasilisation and knowledge engineering","Schut, E.J.","Van Tooren, M.J.L. (promotor)","2010","In order to keep innovating, engineers are working more and more with engineering software, providing them a way to cut away their routine and repetitive activities. Computer aided design and simulation software are for instance considered standard tools in most engineering companies. Today, to solve complex engineering design problems, multidisciplinary design optimisation (MDO) is increasingly used to automate the design process to support the engineer in finding a solution faster. To effectively use MDO, design frameworks such as the design and engineering engine (DEE) are required. More and more does engineering software provide a seamless integration of computer software and human knowledge, a focus point of the field of knowledge engineering (KE). This will free engineers from repetitive and routine tasks and allow them to use their full creative capacity and learn faster, increasing their productivity. This work contributes to the development of KE applications within the DEE to support the MDO process. The focus is on the conceptual design phase of complex systems engineering, responsible for providing an initial start vector for MDO. Aircraft design is taken as a guiding example as it is a typical case of a complex system.","Knowledge Based Engineering; Conceptual Design; Aircraft Design; Feasilisation; Multidisciplinary Design Optimisation; Systems Engineering; Complex systems; Design Automation","en","doctoral thesis","E.J. Schut","","","","","","","","Aerospace Engineering","Design of Aircraft and Rotorcraft","","","",""
"uuid:aae3e171-cd2a-4700-b17c-1ba9ea005e8c","http://resolver.tudelft.nl/uuid:aae3e171-cd2a-4700-b17c-1ba9ea005e8c","Human Handheld-Device Interaction: An Adaptive User Interface","Fitrianie, S.","Koppelaar, H. (promotor); Rothkrantz, L.J.M. (promotor)","2010","The move to smaller, lighter and more powerful (mobile) handheld devices, whe-ther PDAs or smart-phones, looks like a trend that is building up speed. With numerous embedded technologies and wireless connectivity, the drift opens up unlimited opportunities in daily activities that are both more efficient and more exciting. Despite all these advancing possibilities, the shrinking size and the mobile use impose challenges for both technical and usability aspects of the devices and their applications. An adaptive user interface, that is able to autonomously adjust its display and available actions to current goals, contexts and emotions of its user, represents solutions for limited input options, various constraints of the output presentation, and user requirements due to mobility and attention shifting in human handheld-device interaction. The present work made preliminary steps in proposing a framework for a rapid construction of adaptive user interfaces that are multimodal, context-aware and affective, on handheld devices. The framework consists of predefined modules that are able to work in isolation but can also be connected in an ad hoc way as part of the framework. The modules deal with human handheld-device interaction, the interpretation of the user's actions, knowledge structure and management, the selection of appropriate responses and the presentation of feedback. Human language and visual perception models have been studied in formulating concepts or ideas as both text and visual language-based messages. An adaptive circular on-screen keyboard and visual language-based interfaces have been proposed as alternative input options for fast interaction. In particular, sentences in the visual language can be constructed using spatial arrangements of visual symbols, such as icons, lines, arrows and ellipses. As icons offer a potential across language barriers, any interaction using the visual language is suitable for language-independent contexts. Personalized predictive and language-based features have also been added to accelerate both input methods. An ontology has been chosen to represent knowledge of the user, the task and the world. The modeling and structure of the knowledge representation has been designed for sharing common semantics, integrating the communication inter-modules, and fulfilling the context aware requirement. It enables the framework to be developed into a widespread application for different domains. The context awareness is approached by interpreting both verbal and non-verbal aspects of user inputs to update the system's belief about the user, the task and the world. Methods and techniques to fuse multiple input modalities for multiple messages from multiple users into a coherence and context dependent interpretation have been developed. A simple approach to emotion analysis has been proposed to interpret the nonverbal aspect of the inputs. It is based on a keyword spotting approach by categorizing the emotional state into a certain valence orientation with intensity. The approach is suitable for a high uncertainties input recognition. Template-based interaction management and output generation methods have been developed. The templates have a direct link to concepts in the ontology-based knowledge representation. This approach supports a common semantic with other modules within the framework. It allows the development of a bigger scale system with consistent and easy to verify knowledge repositories. A multimodal, multi-user, and multi-device communication system in the field of crisis management built based on the framework has been developed as a proof of the proposed concepts. This system consists of comprehensive selected modules for reporting and collaborating observations using handheld devices in mobile ad-hoc network-based communication. It supports communication using the combination of text, visual language and graphics. The system is able to interpret user messages, construct knowledge of the user, the task and the world, and develop a crisis scenario. User tests were aimed at an assessment of whether or not users are capable of expressing their messages using the provided modalities. The tests also addressed usability issues on interacting with an adaptive user interface on handheld devices. The experimental results indicated that the adaptive user interface is able to support communication between users and between users and their handheld devices. Moreover, an explorative study within this research has also generated knowledge regarding (technical, social and usability aspects of) user requirements in adaptive user interfaces and (generally) human handheld-device interaction. The rationale behind our approaches, designs, empirical evaluations and implications for research on the framework for an adaptive user interface on handheld devices are also described in this thesis.","Human Computer Interaction; Adaptive User Interface; Artificial Intelligent; Natural Language Processing; Software Engineering; Multimodal System; Handheld Device Application; Software Framework; Knowledge Engineering; Situation Awareness; Communication","en","doctoral thesis","Mediamatics","","","","","","","2010-11-12","Electrical Engineering, Mathematics and Computer Science","Man Machine Interaction, Mediamatics","","","",""
"uuid:71828106-1b67-44b9-b87b-50a4f0c67c5f","http://resolver.tudelft.nl/uuid:71828106-1b67-44b9-b87b-50a4f0c67c5f","Effects of river floodplain lowering and vegetation cover","Villada Arroyave, J.A.; Crosato, A.","","2010","The current river management policy in the Netherlands is to give rivers more space, mainly by main channel widening and floodplain lowering. The aim is to reduce flood water levels and to create more favourable conditions for river ecology. However, the effect on water levels gradually disappears due to sedimentation and vegetation growth on floodplains. The key questions are how effective these measures are and how long the desired effect remains. A two-dimensional, depthaveraged, morphological model was applied to the Meers pilot project on the Common Meuse River. The project consisted of channel widening by floodplain excavation, carried out over a short reach. Spatially varying floodplain vegetation was included. The results showed that the pilot project would be effective in lowering local water levels during a period of 20 years for floods having a return period of 1–4 years but not for floods having a return period of 100 years. In the latter case, water levels would be dominated by a restriction in floodplain width, causing backwater effects. Floodplain vegetation was found to shorten the lifetime of the project by enhancing sedimentation.","river engineering; floods; floodworks","en","journal article","ICE Publishing","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:0ad18c73-7cca-47fb-bf9b-4cc887b8ba04","http://resolver.tudelft.nl/uuid:0ad18c73-7cca-47fb-bf9b-4cc887b8ba04","Teaching environmental sustainability in higher education","Itard, L.; Van den Bogaard, M.; Hasselaar, E.","","2010","The challenges of sustainable engineering and design are complex and so are the challenges of teaching sustainability to higher education students. This paper deals with teaching environmental sustainability, with a specific focus on the sustainability of buildings. The paper addresses specifically the higher professional and academic education. What do we know about the efficiency of courses on sustainability as they are currently offered and what do students need to experience in their curriculum to be able to appreciate the challenge of sustainable engineering? There always seem to be three major problems: (1) the definition of the concept of sustainable engineering, which is ill-defined and on which there is little general agreement, (2) the fact that sustainable engineering has to integrate many different disciplines, while curricula are mostly monodisciplinary, and (3) the fact that environmental sciences are still under development and suffer from progressive insights. This paper addresses these three stumbling blocks and bring them in relation with the basic principles of education and course design: How to deal with the ill-defined concept of sustainability in curricula? What are the implications of teaching a discipline that is still under rapid development? What are possible conflicts between multidisciplinary and monodisciplinary approaches of education in sustainability?","environmental sustainablility; education; teaching; sustainable engineering; multidisciplinary approach","en","conference paper","","","","","","","","","","","","","",""
"uuid:7af201f6-76a7-44d3-9aee-0420052f3e0e","http://resolver.tudelft.nl/uuid:7af201f6-76a7-44d3-9aee-0420052f3e0e","Major challenges to education for sustainable development: Can the current nature of institutions of higher education hope to educate the change agents needed for sustainable development? Massachusetts Institute of Technology, USA","Ashford, N.A.","","2010","Scholars and professionals committed to fostering sustainable development have urged a re-examination of the curriculum and restructuring of research and teaching in institutions of higher learning. This paper begins by discussing an expansive definition of sustainable development that includes economic, environmental, and employment concerns important to both developed and developing nations; then distinguishes inter-disciplinary, multi-disciplinary, and trans-disciplinary problem solving; and finally argues that the policy sciences are different from policy engineering. The paper then addresses the following themes and questions: (1) How can multi- and trans-disciplinary research and teaching coexist in a meaningful way in today?s university structures? (2) Does education relevant to sustainable development require its own protected incubating environment to survive, or will it otherwise be gobbled up and marginalized by attempting to instill it throughout the traditional curriculum and traditional disciplines? (3) How can difficulties in linking the needed teaching and research be overcome? (4) Even if there exist technical options to do so, how can it be made safe for courageous students to take educational paths different from traditional tracks and find adequate financial support for their studies? (5) What roles can national and EU governments have in accelerating the needed changes? and (6) What can we learn from comparative analysis of universities in different nations and environments?","education; industrial policy; interdisciplinary; labour; multidisciplinary; policy; policy analysis; policy engineering; sustainability; sustainable development; transdisciplinary","en","conference paper","","","","","","","","","","","","","",""
"uuid:99ed4c0a-a05a-4693-b7e8-a8d6ec10112c","http://resolver.tudelft.nl/uuid:99ed4c0a-a05a-4693-b7e8-a8d6ec10112c","Integrating sustainable development into the undergraduate engineering curriculum through a mandatory first year engineering design course at the University of Toronto","Heeney, A.; Foster, J.","","2010","This paper discusses how Engineering Science, an undergraduate division within the Faculty of Engineering at the University of Toronto in Toronto, Canada, has worked to foster engineers that can meaningfully contribute to sustainable development (SD). Specifically, Engineering Science has developed ESC102: Praxis II, a core course required for all first year undergraduate Engineering Science students, which takes both a systems engineering and an interdisciplinary approach to solving complex problems in a local context. All Engineering Science students take Praxis II, and are exposed to sustainable development concepts even if they had no prior interest in sustainable development (SD). The 2010 Praxis II course integrated SD concepts by explicitly requiring students to consider and develop sustainability requirements, using the ""DfX"" concepts from the ""Design for Sustainability"" (DfS) and ""Design for Environment""(DfE) literature, and incorporate sustainable design concepts into their final projects. Students were guided in these activities through introductory lectures, discussion groups, and tutorial activities. Sustainable design was also an explicit part of the assignment requirements. This paper discusses the goals, process, and success of the 2010 Praxis II course curriculum integration of sustainable development concepts. It discusses the specific training in problem-solving and sustainability concepts that students received, and the challenges students faced in applying SD concepts to their solutions. We also explore how to improve student engagement in and student acceptance of SD concepts. Finally, we summarize the lessons learned for integrating SD concepts into an engineering design course.","Engineering Education; Sustainable Design; Curriculum Integration; Systems Engineering; Undergraduate Curriculum","en","conference paper","","","","","","","","","","","","","",""
"uuid:8273a178-3fff-42ac-b75a-a265d3a15233","http://resolver.tudelft.nl/uuid:8273a178-3fff-42ac-b75a-a265d3a15233","Ecodynamic design as a boundary object","Van Slobbe, E.","","2010","Consensus in Dutch society is that the existing coastal defence regime is not sustainable. Adaptation is not only a technical challenge, but affects elements like ecology, cultural heritage, recreation, urban development, making the issue complex both from a political and from a scientific point of view. And innovations must cope with the actual system of human beliefs, values and knowledges which constitute the old coastal management regime. One possible new regime is ecodynamic design. This is an approach using interactions between ecological processes and human interventions to create new coastal structures. The Building with Nature innovation program is implementing ecodynamic experiments along the Dutch coast. One of these is an experiment along the Frisian IJsselmeer coast in the Netherlands. Participating actors (governments, NGOs, private partners) frame it as an adaptive action, potentially providing new flood defence methods to the region. The aim of this paper is to explore the role this Building with Nature experiment plays in the interactions between actors with different perspectives and how the experiment influences collaborative learning. This case is analysed using the concept of boundary objects.","adaptive action; learning; ecosystem engineering; boundary objects","en","conference paper","","","","","","","","","","","","","",""
"uuid:106f2c9f-c82b-458e-b7a5-27550dae7287","http://resolver.tudelft.nl/uuid:106f2c9f-c82b-458e-b7a5-27550dae7287","Teaching environmental sustainability in higher education","Itard, L.C.M.; Van den Bogaard, M.E.D.; Hasselaar, E.","","2010","The challenges of sustainable engineering and design are complex and so are the challenges of teaching sustainability to higher education students. This paper deals with teaching environmental sustainability, with a specific focus on the sustainability of buildings. The paper addresses specifically the higher professional and academic education. What do we know about the efficiency of courses on sustainability as they are currently offered and what do students need to experience in their curriculum to be able to appreciate the challenge of sustainable engineering? There always seem to be three major problems: (1) the definition of the concept of sustainable engineering, which is ill-defined and on which there is little general agreement, (2) the fact that sustainable engineering has to integrate many different disciplines, while curricula are mostly monodisciplinary, and (3) the fact that environmental sciences are still under development and suffer from progressive insights. This paper addresses these three stumbling blocks and bring them in relation with the basic principles of education and course design: How to deal with the ill-defined concept of sustainability in curricula? What are the implications of teaching a discipline that is still under rapid development? What are possible conflicts between multidisciplinary and monodisciplinary approaches of education in sustainability?","environmental sustainability; education; teaching; sustainable engineering; multidisciplinary approach","en","conference paper","","","","","","","","","OTB Research Institute","","","","",""
"uuid:721f82a4-a7f4-4cfa-afc2-d4ffa131bf11","http://resolver.tudelft.nl/uuid:721f82a4-a7f4-4cfa-afc2-d4ffa131bf11","Promoting academia-industry cooperation for innovation","Crul, M.R.M.; Schnitzer, H.","","2010","Innovation and Innovation Management are essential instruments and methodologies to manage the changes that society and its productive sector are facing in order to find the right balance between competitiveness, trade demands, social equity and sustainable development. A clear role in this can be played by the local universities and by an international network of higher education institutions. The EU/Tempus UNCHAIN project proposal takes its origin from an initiative started in 2007 by the Rectors of three European Universities (Delft University of Technology, Graz University of Technology, and the Politecnico di Milano) aiming at establishing a “Global Network of University Chairs on Innovation”. The overall objective of the UNCHAIN project is to bridge the gap between the innovation needs of industry and the supply of universities, in terms of human resources and technologies, by establishing a “University Chair on Innovation”. At 6 universities in the east and south Mediterranean region (the MEDA region), SEKEM and Cairo University in Egypt, Hassan II in Morocco, Aleppo in Syria, S. Joseph in Lebanon and Sfax in Tunesia, specific problems and obstacles facing innovation and the universityindustry relation have been analysed. In each of the universities a Chair on Innovation has been established in 2009. This Chair, together with the international partners, is responsible for developing Technology Transfer Policy, initiating a re-skilling program on Innovation, development of an EU-MEDA Twinning MSc Thesis Program, and development of an EUMEDA Virtual Environment and Strategy for University-Industry Cooperation in Innovation. This paper describes the challenges and results of this project.","university cooperation; capacity building in engineering; innovation; university-industry; partnership","en","conference paper","","","","","","","","","Industrial Design Engineering","","","","",""
"uuid:69e0c4fc-53f7-42e8-93cf-aaff5dd472c5","http://resolver.tudelft.nl/uuid:69e0c4fc-53f7-42e8-93cf-aaff5dd472c5","Promoting academia-industry cooperation for innovation: A network of university chairs in The Middle East and North Africa","Crul, M.; Schnitzer, H.","","2010","Innovation and Innovation Management are essential instruments and methodologies to manage the changes that society and its productive sector are facing in order to find the right balance between competitiveness, trade demands, social equity and sustainable development. A clear role in this can be played by the local universities and by an international network of higher education institutions. The EU/Tempus UNCHAIN project proposal takes its origin from an initiative started in 2007 by the Rectors of three European Universities (Delft University of Technology, Graz University of Technology, and the Politecnico di Milano) aiming at establishing a Global Network of University Chairs on Innovation. The overall objective of the UNCHAIN project is to bridge the gap between the innovation needs of industry and the supply of universities, in terms of human resources and technologies, by establishing a University Chair on Innovation. At 6 universities in the east and south Mediterranean region (the MEDA region), SEKEM and Cairo University in Egypt, Hassan II in Morocco, Aleppo in Syria, S. Joseph in Lebanon and Sfax in Tunesia, specific problems and obstacles facing innovation and the university industry relation have been analysed. In each of the universities a Chair on Innovation has been established in 2009. This Chair, together with the international partners, is responsible for developing Technology Transfer Policy, initiating a re-skilling program on Innovation, development of an EU-MEDA Twinning MSc Thesis Program, and development of an EUMEDA Virtual Environment and Strategy for University-Industry Cooperation in Innovation. This paper describes the challenges and results of this project.","university cooperation; capacity building in engineering; innovation; university-industry partnership","en","conference paper","","","","","","","","","","","","","",""
"uuid:d93296a0-fd72-4f22-b3a2-1a8e0d80f003","http://resolver.tudelft.nl/uuid:d93296a0-fd72-4f22-b3a2-1a8e0d80f003","Industrial ecosystems as a social network","Rui, J.; Heijungs, R.","","2010","With solid theoretical support from industrial ecology, an increasing number of industrial ecosystems (including eco-industrial parks and industrial symbiosis) have been created all over the world. There is no doubt that the Kalundborg symbiosis, which has steadily operates for thirty years, is our successful exemplar, although some problems also occurred in its history. However, we must realize that the Kalundborg symbiosis is not directly replicable elsewhere due to its special location and social surrounding. Indeed, designed EIPs (especially in the US in the 1990s) have often resulted in failures, and most identifiable EIPs are still at a very early stage or transformation to an industrial ecosystem. The study of critical factors of EIPs is therefore important. One question is how to use typical IE tools, like MFA and LCA in EIPs. Recently, attention has been given to indentify and promote uncovering industrial symbiosis from the social perspective. Since an industrial ecosystem is a regional community with waste or byproduct links, cooperation and coordination among firms plays an important role. Researchers investigate this issue from multi-disciplines knowledge, such as social network approach, complex systems science, and system engineering to simulate the development, to evaluate an industrial ecosystem, or to help transformation of a traditional industrial system toward an EIP. Along this line, we should always reflect on to what extent IES could achieve resource recovery and sustainability. Uncertainty factors and reasons of failed IES should be further examined. Metrics or standards of successful industrial systems should be further clarified. This presentation will sketch some of these newer developments.","industrial ecosystems; social network; complex systems science; system engineering","en","conference paper","","","","","","","","","","","","","",""
"uuid:0af8c4fa-5e6f-4328-b933-0e6af240ea99","http://resolver.tudelft.nl/uuid:0af8c4fa-5e6f-4328-b933-0e6af240ea99","Ecological Automation Design, Extending Work Domain Analysis","Amelink, M.H.J.","Mulder, J.A. (promotor); Mulder, M. (promotor)","2010","In high–risk domains like aviation, medicine and nuclear power plant control, automation has enabled new capabilities, increased the economy of operation and has greatly contributed to safety. However, automation increases the number of couplings in a system, which can inadvertently lead to more complexity from the perspective of the operator. The automation of a system transforms the work domain of the human operator, and his role changes from controlling the core processes to managing the automated processes. The complexity of the automation and the lack of proper support can make the control task’s overall difficulty larger than it needs to be, restricting safety, productivity, and efficiency. To address and limit the automation introduced complexity in the operator’s work domain, and to find representations to support him, the ecological approach to automation design was taken. The ecological approach focuses on the relationship between the human operator and his work domain including the system he is controlling. The main research goals were to find how the ecological approach could be used to help limit the automation introduced complexity, and how the ecological approach could be used to support the human operator in controlling automated processes. The formulation of Ecological Automation Design (EAD) was based on the Ecological Interface Design (EID) paradigm. One of the main underlying questions asked about the interface between the work domain and the human operator is: “how to represent work domain complexity?"". The inter face design paradigm was transformed into an automation design paradigm by first separating the automation component from the work domain and asking the same underlying question about the interfaces between the work domain, the human operator, and the automation. Then, the conceptual shared domain representation was defined to visualize that the apparent complexity of the system could be reduced when both the human operator and the automation view the same representation of constraints that the work domain imposes on control. As part of the ecological approach, Work Domain Analysis (WDA) was used to analyze and represent the constraints in a work domain. However, WDA is not yet fully developed and suffers from some methodological and conceptual issues. The research therefore, focused on the further development and extension of WDA to include the representation of automated processes. Four case studies were conducted, and each case study generated new insights into the application of and extension of WDA. In the first case study, EID was applied to the design of the Energy Augmented Tunnel In the Sky display. This display was designed to aid a pilot to fly the approach to landing by presenting energy management information. The WDA revealed the significance of the energy coupling between vertical flight path and speed control as an intermediate control goal. Based on the analysis, a creative design process resulted in a novel display that has the energy representations fully, and graphically integrated in the tunnel in the sky display. A preliminary evaluation indicated that the additional energy management information shown in relation to the control actions and control goals helped pilots to fly the approaches. The display is not expected to give a performance increase but to change the way in which pilots control the throttle and elevator to fly approaches. The second case study was the analysis of the already existing Total Energy Control System (TECS). TECS is an unconventional automated flight control system that was based on the same energy management constraints as that were represented in the energy augmented display of the first case study. The design of TECS was mapped onto the abstraction hierarchy to represent the energy management principles as part of the whole automated system. The analysis and useful representation of TECS using the abstraction hierarchy was not straightforward. It involved a search for the interpretation of the levels of the abstraction hierarchy and the use of the means–ends relationship in conjunction with the aggregation relationship. The resulting WDA showed that the abstraction hierarchy could be used to map out the reasons for TECS’s design features. Many constraints were represented in the same space, which cluttered the energy management principles. The focus was put on the energy management principles through selective aggregation of the represented functions, but other design principles were omitted. To provide a complete representation of the system but without the clutter, the levels of control sophistication were introduced to represented nested control problems separately. At each level of control sophistication the abstraction hierarchy was applied, resulting in the Abstraction–Sophistication Analysis (ASA). In the third case study, the ASA framework was used to guide the design of SmartUAV. SmartUAV is a newly designed mini–UAV system that is capable of controlling multiple small UAVs from a laptop computer. By designing and developing SmartUAV we gained hands–on experience with how WDA, and especially the ASA, helped to keep track of and deal with the automation introduced constraints in the design phase. The levels of control sophistication were used from the beginning to separate the different control problems in the domain. They ranged from flying the platform to the achievement of missions. Starting at the lowest level of control sophistication, each higher level allowed the designer to include a larger part of the complete work domain incrementally, and to focus on more sophisticated control of the UAV. Furthermore, the ASA supported the visualization of how automation transformed the work domain, thus how automated functionalities that were created at lower levels of control sophistication affected the (automated) functions at higher levels of control sophistication. This study showed that the ASA could span a much larger problem space than the original WDA through the nesting of abstraction hierarchies. The ASA provided a systematic way to address the abstraction of the control problems (levels of control sophistication) and the abstraction of functions per control problem (abstraction hierarchy). The fourth case study dealt with the analysis of a subset of a well structured domain that lacks automation; sailboat racing. This study generated a clearer view on the nested structure that is inherent in a work domain, as apposed to the nested structure of the automation as found in TECS and SmartUAV. The nested structure inherent to this work domain was found to be the result of how sailboat racing has evolved over time, based on the capabilities of equipment, human performance and the racing rules. Due to the lack of automation, it became clear that human performance is in fact part of the work domain, in contrast to the original formulations of WDA. The crew’s performance formed the basis for achieving the more sophisticated control of boat speed, tactics and strategy, thus was essential in the analysis. It was shown that the performance of the human crew could be represented in the ASA at a level of control sophistication, while this could not be supported in a non–nested WDA based on a single abstraction hierarchy. The four case studies exemplified WDA and led to its extension with a structure to explicitly nest abstraction hierarchies that map out different control problems: the ASA. Through generating the analyses, extensive modeling experience with the abstraction hierarchy was obtained, reducing its ambiguity and potential methodological and conceptual problems. We found that the abstraction hierarchy could be used to model the structure of the knowledge about a work domain but could not model the knowledge itself. Therefore, the abstraction hierarchy is a framework for structuring knowledge, linking different representations of a control problem, and explaining the reasons for design features of a system. The abstraction hierarchy addressed the abstraction of elements belonging to a control problem, and the levels of control sophistication addressed the abstraction of the control problem itself. Representations in the ASA framework ranged from physical at the lower levels of control sophistication to non–physical at the higher levels of control sophistication. It allowed the structuring of, for example: the sailboat racing rules at the higher levels, and the law of conservation of energy at the lower levels. Although the application of the ASA did not inherently reduce the complexity of the design of SmartUAV, it enabled us to better understand the elements of the work domain that contribute to complexity of the system prior to and during its design. The extension of work domain analysis with the levels of control sophistication has led to a richer representation of the studied work domains than a single abstraction hierarchy or the abstraction–decomposition space.","cognitive systems engineering; human factors; work domain analysis; abstraction hierarchy; ecological interface design","en","doctoral thesis","","","","","","","","","Aerospace Engineering","Control and Simulation","","","",""
"uuid:cd04ee91-c634-49c8-a295-fc9d7caab72f","http://resolver.tudelft.nl/uuid:cd04ee91-c634-49c8-a295-fc9d7caab72f","Emotional Engineers: Toward Morally Responsible Design","Roeser, S.","","2010","Engineers are normally seen as the archetype of people who make decisions in a rational and quantitative way. However, technological design is not value neutral. The way a technology is designed determines its possibilities, which can, for better or for worse, have consequences for human wellbeing. This leads various scholars to the claim that engineers should explicitly take into account ethical considerations. They are at the cradle of new technological developments and can thereby influence the possible risks and benefits more directly than anybody else. I have argued elsewhere that emotions are an indispensable source of ethical insight into ethical aspects of risk. In this paper I will argue that this means that engineers should also include emotional reflection into their work. This requires a new understanding of the competencies of engineers: they should not be unemotional calculators; quite the opposite, they should work to cultivate their moral emotions and sensitivity, in order to be engaged in morally responsible engineering.","engineering; design; responsibility; risk; emotion","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:e7d22779-a326-4b44-898d-38ed6799a5e7","http://resolver.tudelft.nl/uuid:e7d22779-a326-4b44-898d-38ed6799a5e7","Cytosolic NADPH balancing in Penicillium chrysogenum cultivated on mixtures of glucose and ethanol","Zhao, Z.; Kuijvenhoven, K.; Van Gulik, W.M.; Heijnen, J.J.; Van Winden, W.A.; Verheijen, P.J.T.","","2010","The in vivo flux through the oxidative branch of the pentose phosphate pathway (oxPPP) in Penicillium chrysogenum was determined during growth in glucose/ethanol carbon-limited chemostat cultures, at the same growth rate. Non-stationary 13C flux analysis was used to measure the oxPPP flux. A nearly constant oxPPP flux was found for all glucose/ethanol ratios studied. This indicates that the cytosolic NADPH supply is independent of the amount of assimilated ethanol. The cofactor assignment in the model of van Gulik et al. (Biotechnol Bioeng 68(6):602–618, 2000) was supported using the published genome annotation of P. chrysogenum.Metabolic flux analysis showed that NADPH requirements in the cytosol remain nearly the same in these experiments due to constant biomass growth. Based on the cytosolic NADPH balance, it is known that the cytosolic aldehyde dehydrogenase in P. chrysogenum is NAD+ dependent. Metabolic modeling shows that changing the NAD+-aldehyde dehydrogenase to NADP+-aldehyde dehydrogenase can increase the penicillin yield on substrate.","isotopic non-stationary 13C flux analysis; metabolic flux ratio analysis; pentose phosphate pathway; metabolic engineering; NADPH metabolism","en","journal article","Springer","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:1f7fd890-494f-44de-945b-1c761dd36eb7","http://resolver.tudelft.nl/uuid:1f7fd890-494f-44de-945b-1c761dd36eb7","Concepts and contexts in engineering and technology education: An international and interdisciplinary Delphi study","Rossouw, A.; Hacker, M.; De Vries, M.J.","","2010","Inspired by a similar study by Osborne et al. we have conducted a Delphi study among experts to identify key concepts to be taught in engineering and technology education and relevant and meaningful contexts through which these concepts can be taught and learnt. By submitting the outcomes of the Delphi study to a panel of experts in a twoday meeting we were able to add structure to the Delphi results. Thus we reached a concise list of concepts and contexts that can be used to develop curricula for education about engineering and technology as a contribution to technological literacy goals in education.","delphi study; engineering and technology education; concept-context; expert panel; engineering and technology education curriculum development; technological literacy; ETE; teaching concepts in contexts","en","journal article","Springer Verlag","","","","","","","","Applied Sciences","Science Education and Communication","","","",""
"uuid:50ce6b20-2ea9-434b-8fdd-bed2fe63d323","http://resolver.tudelft.nl/uuid:50ce6b20-2ea9-434b-8fdd-bed2fe63d323","1000 Flowers: International Dimensions to Education","Klaassen, R.G. (TU Delft Teaching & Learning Services); schoemaker, henriette","","2010","The number of students and staff members from abroad is growing. Each of these individuals will influence the way research is interpreted and communicator in teaching and eventually adopted by students. An awareness of the impact of this diversity will prepare students and staff alike for their role in the multicultural environment within the scientific community and in society at large","grassroots; internationalisation; Engineering education","en","other","","","","","","","","","","","Teaching & Learning Services","","",""
"uuid:3601e78e-d45c-43d6-9bcf-e3d6113cd502","http://resolver.tudelft.nl/uuid:3601e78e-d45c-43d6-9bcf-e3d6113cd502","What's new?: Farewell Address","Ligteringen, H.","","2010","Farewell address","Uittreerede; port engineering; port masterplan","en","public lecture","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:a8dd2b93-1269-46f8-a22e-1a5f36654340","http://resolver.tudelft.nl/uuid:a8dd2b93-1269-46f8-a22e-1a5f36654340","Development of a task-based design approach for solution crystallization processes","Lakerveld, R.","Grievink, J. (promotor); Jansens, P.J. (promotor); Kramer, H.J.M. (promotor)","2010","Crystallization is historically one of the most important separation and product formation technologies in chemical industry. The future impact of crystallization is expected to increase as new high-added value products are often in crystalline form and need to comply with increasingly stringent product quality requirements. This calls for better designs and performance of new crystallization units in chemical processes. A key challenge is to improve in the design phase the control over the physical phenomena dominating the process performance and product quality. This thesis aims to provide a foundation for a novel task-based design approach to improve the control over individual physical phenomena. Firstly, a task-based decomposition strategy for design is developed leading to a multi-level and multi-scale design approach. The performance of individual tasks considered in this conceptual framework should be practically feasible and effective. Therefore, secondly, control over several key crystallization tasks in novel processing units is experimentally investigated, including a) ultrasound for improved control over nucleation b) membrane assisted crystallization for improved control over supersaturation generation c) air-mixed devices (bubble column and airlift column) to provide mixing with low shear forces for improved control over crystal growth d) an integrated approach for improved control over seeding application. An exciting strength lies in the integration of the processing units by using task-based principles. Therefore, thirdly, model-based dynamic optimization for two case studies is applied. The results show that the investigated processing units for selective task manipulation can individually contribute to an improved crystallizer design. However, the true strength lies in the integration. Dynamic model-based optimization of an integrated task-based crystallizer results in a surprising flexibility to produce different grades of product. This flexibility is the result of the ability to manipulate tasks independently from each other, which is poorly possible in conventional crystallization equipment.","Crystallization; Task-based design; Ultrasound; Membranes; Airlift column; Bubble column; Seeding; Systems Engineering; Dynamic optimization","en","doctoral thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Process and Energy","","","",""
"uuid:ac25ec15-698b-4c46-a02f-c7115cdcea27","http://resolver.tudelft.nl/uuid:ac25ec15-698b-4c46-a02f-c7115cdcea27","Decomposition methods for distributed control and identification","Massioni, P.","Verhaegen, M. (promotor)","2010","The recent progress in technology, as in miniaturization and microtechnologies, is now forcing control engineers to confront themselves with systems of incredibly high dimensionality, with an ever growing number of input and output channels. For such systems, which we call ""large scale systems"", it is necessary to take a new approach in order to solve control problems in a reasonable time, as well as for being able to design controllers which can be realized in a physically implementable way. This thesis concerns a class of linear time-invariant large scale systems which we call ""decomposable systems"". Decomposable systems describe systems made of a set of identical subsystems (or agents) that are interacting with each other, and they can be considered as an example of homogeneous systems with arbitrary interconnections. This means that each subsystem interacts only with a limited set of the others, and the interconnection pattern does not have to stick to a special structure or lattice. This class of systems describes very well a number of physical systems of interest, such as formations of vehicles or mechanical elements made of identical subparts. Decomposable systems are interesting under the point of view of the theory as they prove to be amenable to a kind of modal decomposition that depends only on the interconnection pattern and not on the specific system; this property, or ""decomposition theorem"", is at the basis of all the results shown in this thesis. The first part of this work concerns the problem of synthesizing distributed controllers for decomposable systems. By ""distributed"", we mean that the controller can be implemented as a set of simple, local controllers interacting with each other, each of them commanding a limited set of neighboring subsystems. This approach is demanded when the number of subsystems is very high: in this case it is not feasible to implement a centralized controller that reads all the outputs and decides all the control inputs. The decomposition property is exploited to convert the problem of controller synthesis for the global decomposable system into the problem of synthesizing controllers for the ""modal"" systems making up its decomposed version; such modal subsystems have the same order as a single agent. Then, by using techniques from robust control as well as a few results from graph theory, it is possible to cast the distributed controller synthesis problem as an optimization problem under Linear Matrix Inequality constraints. This leads to methods allowing performance-based synthesis of controllers in a variety of cases (e.g. H-2 or H-infinity performance, continuous or discrete time, state or output feedback). The methods only offer suboptimality results, which can be considered as the price to be paid in exchange for the distributed structure of the controller. The distributed controller methods are then used in simulation for two examples of relevant technological application. The first application is the distributed H-2 control of a deformable mirror for adaptive optics; as future Earth-based telescopes will feature deformable mirrors with actuators and sensors in the order of the thousands, the independence of the computational complexity from the system size makes the methods of this thesis very attractive. The second application considered is satellite formation flying, for which an extension of the H-infinity methods to the time-varying case is proposed. The controller is evaluated on two examples of space missions involving non-Keplerian orbits. The last part of the thesis concerns a problem that is complementary to the one of control; namely, it investigates the possibility of identifying models of decomposable systems from data. This possibility is useful in case such models are not available from first principles. It is shown that the decomposition property can be used in this case as well. The problem is first treated for a special case, namely for the class of circulant systems, and then examined in the general case. An approach based on subspace identification is proposed.","control engineering,; large scale systems","en","doctoral thesis","","","","","","","","2010-06-21","Mechanical, Maritime and Materials Engineering","Delft Center for Systems and Control","","","",""
"uuid:2cfad6e4-e705-4483-806e-cea838d03479","http://resolver.tudelft.nl/uuid:2cfad6e4-e705-4483-806e-cea838d03479","Model Structure Analysis of Model-based Operation of Petroleum Reservoirs","Van Doren, J.F.M.","Van den Hof, P.M.J. (promotor); Jansen, J.D. (promotor)","2010","The demand for petroleum is expected to increase in the coming decades, while the production of petroleum from subsurface reservoirs is becoming increasingly complex. To meet the demand petroleum reservoirs should be operated more efficiently. Physics-based petroleum reservoir models that describe the flow in subsurface porous media can play an important role here. In this thesis possibilities are investigated to determine on one hand models with a complexity that is suitable for model-based operation (i.e. the relevant dynamic processes can be adequately described), and on the other hand models that only contain parameters that can be validated by measurements (in this thesis the pressure and phase-rate measurements in the wells). The most relevant dynamics of the model are determined by the controllability and observability properties. These indicate that reservoir models behave as models of much lower order than the currently used models, and that reduced-order reservoir models should focus for fixed well positions on correctly modeling the fluid front(s). In the second part identifiability and structural identifiability have been quantified and used to determine which (physical) model parameters can be reliably estimated from measurement data. From the analysis it was concluded that the parameters of reservoir models are not identifiable from production measurements and that they are largely based on qualitative geological information. Pressure measurements only contain information about grid block permeabilities in an area close to the wells in which is measured, and phase-rate measurements contain after water breakthrough only information about grid block permeabilities in the area between the injection and production wells. This supports the need to use information of other measurement types, such that better model-based decisions can be taken to make the operation of petroleum reservoirs more efficient.","petroleum reservoir engineering; controllability; observability; identifiability","en","doctoral thesis","","","","","","","","2011-06-14","Mechanical, Maritime and Materials Engineering","Delft Center for Systems and Control","","","",""
"uuid:c1481b1d-9b33-42e4-885a-53a6677843f6","http://resolver.tudelft.nl/uuid:c1481b1d-9b33-42e4-885a-53a6677843f6","Automated rock mass characterisation using 3-D terrestrial laser scanning","Slob, S.","Turner, A.K. (promotor); Bruining, J. (promotor)","2010","The research investigates the possibility of using point cloud data from 3-D terrestrial laser scanning as a basis to characterise discontinuities in exposed rock massed in an automated way. Examples of discontinuities in rock are bedding planes, joints, fractures and schistocity. The characterisation of discontinuities is of importance, since they determine to a large extend the geotechnical behaviour of the entire rock mass. The conventional way of characterising discontinuities is by manual geological survey using geological compass and measuring tape. A logical alternative to the conventional methods for surveying rock faces is the use of 3-D terrestrial laser scanning. A 3-D terrestrial laser scanning survey yield a 3-D point cloud but this data does not yet provide the information on the character of the discontinuities that can be seen in the rock exposure. In this research two different approaches are followed: the first approach uses surface reconstruction through interpolation of the point cloud and the second approach makes use of direct segmentation of the original point cloud. The main conclusion of this research is that it is possible to automate the derivation of discontinuity orientation and spacing information with both methods. Point cloud segmentation is however, the most preferred approach, since it does not require prior surface reconstruction, is therefore faster, and is not strongly influenced by vegetation and other noise in the data. Point cloud segmentation uses the original point cloud, so there is no data loss, which is unavoidable with a surface reconstruction approach.","3-D terrestrial laser scanning; discontinuity characterisation; point cloud segmentation; surface reconstruction; engineering geology; rock mechanics","en","doctoral thesis","","","","","","","","2010-06-11","Civil Engineering and Geosciences","Geotechnology","","","",""
"uuid:6cb5eedf-96f8-4298-bc20-cbb480a62636","http://resolver.tudelft.nl/uuid:6cb5eedf-96f8-4298-bc20-cbb480a62636","Veiligheid waterkeringen bij natuurontwikkeling wetlands in het IJsselmeergebied","Van den Ham, G.; Vastenburg, E.","","2010","Het IJsselmeergebied, waaronder behalve het IJsselmeer ook het Markermeer, IJmeer en de randmeren worden gerekend, heeft thans te lijden onder een achteruitgang van natuur- en landschapskwaliteit en een voordturende hoge ruimtelijke druk. Door alle belanghebbenden en betrokken is erkend dat deze problemen opgelost moeten worden en dat daarvoor een grootschalige herinrichting (of wellicht beter: een grootschalige afronding van de inrichting) van het IJsselmeergebied noodzakelijk is. Vanwege de uiteenlopende visies is het lastig gebleken om tot een voor alle belanghebbenden en betrokken bevredigende totaaloplossing te komen.","vooroevers; dijksterkte; dijkveiligheid; batch berekeningen; automated engineering; DAM; RRD; wetlands; natuurontwikkeling; Delft Cluster; CT04.47.11","nl","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:f3d9fa03-bbda-44b5-b254-3a3cd5c9ea73","http://resolver.tudelft.nl/uuid:f3d9fa03-bbda-44b5-b254-3a3cd5c9ea73","Comparative transcriptomics and proteomics of p-hydroxybenzoate producing Pseudomonas putida S12: Novel responses and implications for strain improvement","Verhoef, A.; Ballerstedt, H.; Volkers, R.J.M.; De Winde, J.H.; Ruijssenaars, H.J.","","2010","A transcriptomics and proteomics approach was employed to study the expression changes associated with p-hydroxybenzoate production by the engineered Pseudomonas putida strain S12pa1B1. To establish p-hydroxybenzoate production, phenylalanine-tyrosine ammonia lyase (pal/tal) was introduced to connect the tyrosine biosynthetic and p-coumarate degradation pathways. In agreement with the efficient p-hydroxybenzoate production, the tyrosine biosynthetic and p-coumarate catabolic pathways were upregulated. Also many transporters were differentially expressed, one of which—a previously uncharacterized multidrug efflux transporter with locus tags PP1271-PP1273—was found to be associated with p-hydroxybenzoate export. In addition to tyrosine biosynthesis, also tyrosine degradative pathways were upregulated. Eliminating the most prominent of these resulted in a 22% p-hydroxybenzoate yield improvement. Remarkably, the upregulation of genes contributing to p-hydroxybenzoate formation was much higher in glucose than in glycerol-cultured cells.","pseudomonas putida S12; p-hydroxybenzoate; transcriptomics; proteomics; metabolic engineering","en","journal article","Springer","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:2624e51d-b2ab-4834-9020-4ca6725d6a60","http://resolver.tudelft.nl/uuid:2624e51d-b2ab-4834-9020-4ca6725d6a60","Thermal Actuation for Precision Micro Motion and Positioning","Paalvast, S.L.","Munnig Schmidt, R.H. (promotor); Sarro, P.M. (promotor)","2010","The primary goal of this research was to study the feasibility of a thermal micro actuator for improved tracking performance of a Hard Disk Drive (HDD), and the feasibility of thermal actuation for precision micro motion and positioning in general. The fast dynamics of the micro actuator allows it to quickly correct position errors and thus improve the tracking accuracy. The improved accuracy is required to reduce the track width of future drives. With these narrower tracks, the HDD industry can maintain their competitive advantage over “flash” based solid state drives, which are currently 4 to 10 times more expensive but are rapidly decreasing in price. Thermal actuation is proposed because thermal actuators can produce a large force with a reasonable displacement and are often of simple construction. Also, they do not require special materials and high driving voltages, unlike piezoelectric actuators. In this work, it was investigated how thermal micro actuators can achieve a sufficiently high bandwidth for precision motion and positioning applications, and how to design, fabricate, and control thermally actuated nanopositioners.","thermal actuation; MEMS; MST; micro actuator; hard disk drive; precision engineering","en","doctoral thesis","","","","","","","","2010-04-05","Mechanical, Maritime and Materials Engineering","Precision and Microsystems Engineering","","","",""
"uuid:594d8c12-ee97-4123-b1fb-c46afa3679a8","http://resolver.tudelft.nl/uuid:594d8c12-ee97-4123-b1fb-c46afa3679a8","Strengthening the link between theory and practice in teaching design engineering: An empirical study on a new approach","Tempelman, E.; Pilot, A.","","2010","In 2007, the Faculty of Industrial Design Engineering of the Delft University of Technology introduced a new bachelor program. Based on theories of learning and instruction three design principles were used to develop an approach that aims to make it easier for students to bridge the gap between theoretical design engineering courses and practical design projects. To investigate whether the new program is successful in this respect, we selected a representative combination of one course and one design project, analysed grades, sent out questionnaires and interviewed teaching staff. The unique change of all three course years at once, as opposed to sequential introduction, allowed us to establish a control group and obtain precise results. By repeating our studies 1 year later, we further enhanced the reliability of our findings. We conclude that our approach indeed strengthens the link between theory and practice, and have reason to be positive about the research method adopted. Furthermore, we identified several barriers that must be overcome for such an approach to become successful, and can now give additional recommendations for course and/or program revisions in teaching design engineering at academic level.","constructivism; course revision; design engineering; education; program revision","en","journal article","Springer Verlag","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:530b0c07-0c91-44d1-b4e9-afce5c237321","http://resolver.tudelft.nl/uuid:530b0c07-0c91-44d1-b4e9-afce5c237321","Bevindingen na ongevalsanalyse: Ongeval op Rijksweg N371 de dato 16 februari 2005","Krieger, R.A.; Hoogstraten, M.; Hogeweg, M.","","2010","Forensische reconstructie van een ongeval met twee voertuigen ter bepaling van de meest waarschijnlijke toedracht. Omvat een vermijdbaarheidsanalyse voor meerdere scenarios naar aanleiding van verklaringen door betrokkenen. Analyse gebaseerd op reconstructietechnieken als zichtlijnen, voertuigtrajecten en -snelheden gedurende de seconden voorafgaand aan het ongeval. Forensic reconstruction of a car crash aiming to determine the most likely sequence of events prior to the mishap. For several situational scenarios, the report analyses the avoidability of the mishap built on techniques such as field-of-vision, vehicle trajectories and velocities for the parties involved during the seconds leading up to the mishap.","ongevalsanalyse; zichtlijn; reconstructie; vermijdbaarheid; forensic engineering","nl","report","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:3001044c-4357-438c-9a5d-e017175f977a","http://resolver.tudelft.nl/uuid:3001044c-4357-438c-9a5d-e017175f977a","Utilizing Uncertainty Multidisciplinary Design Optimization for Conceptual Design of Space Systems","Yao, W.; Guo, J.; Chen, X.; Van Tooren, M.","","2010","With progress of space technology and increase of space mission demand, requirements for robustness and reliability of space systems are ever-increasing. For the whole space mission life cycle, the most important decisions are made in the conceptual design phase, so it is very crucial to take uncertainties into consideration in this initial phase to assure a feasible, reliable and robust conceptual design baseline which dominates the later design direction and life cycle cost. To enhance space system design quality in the conceptual design phase, the utilization of Uncertainty Multidisciplinary Design Optimization (UMDO) in the systems engineering process is systematically studied in this paper. The UMDO theory is introduced and its application in space system design is studied considering the complexity of the system. A small satellite system design case is further discussed to demonstrate the efficacy of UMDO in improving the space system design.","Uncertainty Multidisciplinary Design Optimization; conceptual design; space system engineering","en","conference paper","","","","","","","","","Aerospace Engineering","Space Engineering","","","",""
"uuid:81815b28-ec74-4905-9ec7-ec47261740a1","http://resolver.tudelft.nl/uuid:81815b28-ec74-4905-9ec7-ec47261740a1","Architecture-Driven Integration of Modeling Languages for the Design of Software-Intensive Systems","Dos Santos Soares, M.","Verbraeck, A. (promotor)","2010","In the research that led to this thesis a multi-disciplinary approach, combining Traffic Engineering and Software Engineering, was used. Traffic engineers come up with new control strategies and algorithms for improving traffic. Once new solutions are defined from a Traffic Engineering point of view, there is the problem of obtaining operational systems that address all requirements. Knowing what to build is just the first step that must be followed by the how to build. Both are problematic and they depend on each other. This thesis contributes to Software Engineering research and practice by proposing the extension and integration of formal and semi-formal modeling languages in a multiple-view software architecture, combined with domain architecture, which are used in practice to develop a family of distributed real-time systems in the road traffic domain.","Software-intensive systems; Distributed Real-Time Systems; Software Architecture; Formal Methods; Road Traffic Management Systems; Requirements Engineering; Object-Oriented Modeling","en","doctoral thesis","Next Generation Infrastructures Foundation","","","","","","","","Technology, Policy and Management","Information and Communication Technologies","","","",""
"uuid:b10ee43e-def9-4e02-8571-a495bbe1d361","http://resolver.tudelft.nl/uuid:b10ee43e-def9-4e02-8571-a495bbe1d361","Fluvial design guide","Ackers, J.C.; Rickard, C.J.; Gill, D.S.","TU Delft","2010","The Fluvial design guide is aimed at professional staff engaged in the design process from the early stages of looking at alternative solutions through to the delivery of the outputs of design for the construction, maintenance, refurbishment or alteration of flood defence or land drainage assets. The guide is thus intended to be used by both designers and asset managers. In the field of flood risk management, the management of existing assets (including their ultimate replacement or disposal) is probably more important than the design of new works simply because there are so many of them. The design of any engineering works is an iterative process and the design of works in the fluvial environment is no exception. It is rarely possible to go through the design process without having to step back and re-examine earlier decisions. In addition, a series of related activities run in parallel with the development of the design and feed into it. These include the consideration of risks and uncertainties, the collection of data and consultation with stakeholders. There is also the need to understand the approvals process and the securing of funds for the works. Recognition of these related activities is the key to successful delivery of the outputs of design, though not fundamental to the design process. Introduction Chapter 1: Design of works in the fluvial environment Understanding the fluvial environment Chapter 2: Hydrology Chapter 3: Fluvial geomorphology Chapter 4: Fluvial ecology Chapter 5: Landscape and heritage Chapter 6: Navigation, recreation and amenity Analysis and design Chapter 7: Hydraulic analysis and design Chapter 8: Works in the river channel Chapter 9: Floodwalls and flood embankments Chapter 10: Flood storage works Chapter 11: River and canal structures Glossary","river management; river engineering","en","report","Defra","","","","","","","","","","","","",""
"uuid:320ae614-d8fd-4799-9684-bd4f8feb011d","http://resolver.tudelft.nl/uuid:320ae614-d8fd-4799-9684-bd4f8feb011d","Focusing Automatic Code Inspections","Boogerd, C.J.","Van Deursen, A. (promotor)","2010","Automatic Code Inspection tools help developers in early detection of defects in software. A well-known drawback of many automatic inspection approaches is that they yield too many warnings and require a clearer focus. In this thesis, we provide such focus by proposing two methods to prioritize inspection results, based on the execution likelihood and the historical fault likelihood of warnings. We describe both methods in detail, and evaluate them on various open-source and industry projects.","software engineering; automatic code inspection; static program analysis; software repository mining","en","doctoral thesis","","","","","","","","2009-12-25","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:c82cf5f5-f4c7-4689-999f-9260351ce664","http://resolver.tudelft.nl/uuid:c82cf5f5-f4c7-4689-999f-9260351ce664","NUMERICAL SIMULATION OF EXTREME WAVE IMPACT ON OFFSHORE PLATFORMS AND COASTAL CONSTRUCTIONS","Stapersma, D.","Huijsmans, R.H.M. (advisor)","2010","","Marine Engineer; Propulsion performance; parametric simulation models","","conference paper","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:6d8dad62-03d9-48ef-827c-d8e983909ab6","http://resolver.tudelft.nl/uuid:6d8dad62-03d9-48ef-827c-d8e983909ab6","English Language Screening for Scientific Staff at Delft University of Technology,","Klaassen, R.G. (TU Delft OLD E&SS education center FOCUS); Bos, M.H.P.C. (TU Delft Education and Student Affairs)","","2010","Delft University of Technology (DUT) screened her (non-native English) scientific staff on their level of English proficiency in the academic year of 2006/2007. In this paper this large scale operation, involving planning, policy decisions, assessment means, advice and training are discussed. Since 2005 all the master programmes at DUT have been taught in English and since 3 years ago DUT has been an officially bilingual university with around 5,500 master students and 1,100 international students in the year 2008. Therefore, results are framed against the background of becoming an international university","English medicum instruction; language proficiency; engineering education","en","journal article","","","","","","","","","","","OLD E&SS education center FOCUS","","",""
"uuid:85191798-a57d-4be0-a0c0-7096dc2976fe","http://resolver.tudelft.nl/uuid:85191798-a57d-4be0-a0c0-7096dc2976fe","Safety Concepts in Structural Glass Engineering: Towards an Integrated Approach","Bos, F.P.","Rots, J.G. (promotor); Veer, F.A. (promotor)","2009","This dissertation proposes the Integrated Approach to Structural Glass Safety, based on four clearly defined element safety properties, damage sensitivity, relative resistance, redundancy, and fracture mode. The Element Safety Diagram (ESD) is introduced to provide an easy-to-read graphical representation of these properties. The safety performance of a large number of glass beam designs has been compared through experimental testing based on the proposed approach. The effects of a wide range of safety enhancing design measures on each element safety property is extensively discussed. Elastic strain energy release is identified as a, hitherto underexposed, parameter with major influence on redundancy – the most important safety property. Finally, the Integrated Approach is applied to re-evaluate the safety of two full-scale case-study projects which started this study.","glass; safety; failure; redundancy; damage; structural engineering; energy","en","doctoral thesis","","","","","","","","2009-12-06","Architecture","Building Technology","","","",""
"uuid:57111d23-63b4-4110-bbc6-52f5f7929911","http://resolver.tudelft.nl/uuid:57111d23-63b4-4110-bbc6-52f5f7929911","On the Modelling of Pile Installation","Dijkstra, J.","Van Tol, A.F. (promotor)","2009","This thesis introduces two different types of physical model tests to investigate the stress and density change in the soil during installation of a jacked pile as well as two numerical modelling approaches to model the same process in a finite element code capable of large deformations.","foundation engineering; displacement piles; photoelasticity; geotechnical centrifuge; FEA","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Geotechnology","","Geo-Engineering","",""
"uuid:93978356-2706-4236-b410-3f5a8a0ada71","http://resolver.tudelft.nl/uuid:93978356-2706-4236-b410-3f5a8a0ada71","Sustainability in Design Engineering Education; Experiences in Northern Europe","Dewulf, K.; Wever, R.; Boks, C.; Bakker, C.; D'hulster, F.","","2009","In recent years, the implementation of sustainability into the curricula of engineering has become increasingly important. This paper focuses on the experiences of integrating sustainability in Design Engineering education in the academic bachelor programs at Delft University of Technology in The Netherlands, at the University College of West-Flanders in Belgium, and at the Norwegian University of Science and Technology. The different approaches are described and discussed. This paper aims to share insights and lessons learned in how to accomplish true integration of sustainability in bachelor course curricula of Industrial Design Engineering.","design engineering education; sustainability education; course development; sustainable product innovation","en","conference paper","the Japan Society of Mechanical Engineers","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:a5171933-4169-4761-a7e7-2507abe9a170","http://resolver.tudelft.nl/uuid:a5171933-4169-4761-a7e7-2507abe9a170","Simulation of masonry beams retrofitted with engineered cementitious composites","Kyriakides, M.A.; Billington, S.L.; Hendriks, M.A.N.","","2009","","Unreinforced masonry; engineered cementitious composites; sprayable; retrofit; nonlinear; finite element analysis","en","conference paper","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:3ba999ce-1a50-48d2-919b-8a66777e376a","http://resolver.tudelft.nl/uuid:3ba999ce-1a50-48d2-919b-8a66777e376a","Nonlinear and sequentially linear analysis of tensile strain hardening cement-based composite beams in flexure","Billington, S.L.","","2009","","engineered cementitious composites; flexure; nonlinear finite element analysis; smeared cracking; sequentially linear analysis, sawtooth","en","conference paper","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:1d63f7d5-e9f5-4b4f-a544-a2e2ed2bb28f","http://resolver.tudelft.nl/uuid:1d63f7d5-e9f5-4b4f-a544-a2e2ed2bb28f","Nonlinear and sequentially linear analysis of tensile strain hardening cement-based composite beams in flexure","Billington, S.L.","","2009","","engineered cementitious composites; flexure; nonlinear finite element analysis; smeared cracking; sequentially linear analysis; sawtooth","en","conference paper","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:ab7d534f-4670-4ad4-bf9d-ea3908000045","http://resolver.tudelft.nl/uuid:ab7d534f-4670-4ad4-bf9d-ea3908000045","Responsibility Ascriptions in Technology Development and Engineering: Three Perspectives","Doorn, N.","","2009","In the last decades increasing attention is paid to the topic of responsibility in technology development and engineering. The discussion of this topic is often guided by questions related to liability and blameworthiness. Recent discussions in engineering ethics call for a reconsideration of the traditional quest for responsibility. Rather than on alleged wrongdoing and blaming, the focus should shift to more socially responsible engineering, some authors argue. The present paper aims at exploring the different approaches to responsibility in order to see which one is most appropriate to apply to engineering and technology development. Using the example of the development of a new sewage water treatment technology, the paper shows how different approaches for ascribing responsibilities have different implications for engineering practice in general, and R&D or technological design in particular. It was found that there was a tension between the demands that follow from these different approaches, most notably between efficacy and fairness. Although the consequentialist approach with its efficacy criterion turned out to be most powerful, it was also shown that the fairness of responsibility ascriptions should somehow be taken into account. It is proposed to look for alternative, more procedural ways to approach the fairness of responsibility ascriptions.","responsibility; liability; efficacy; fairness; informed consent; no harm principle; technological risk; engineering practice; consequentialism","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Engineering and Reflection","","","",""
"uuid:48be4903-8349-4d04-b770-921a6bc30ceb","http://resolver.tudelft.nl/uuid:48be4903-8349-4d04-b770-921a6bc30ceb","Code generation by model transformation: A case study in transformation modularity","Hemel, Z.; Kats, L.C.L.; Groenewegen, D.M.; Viser, E.","","2009","The realization of model-driven software development requires effective techniques for implementing code generators for domain-specific languages. This paper identifies techniques for improving separation of concerns in the implementation of generators. The core technique is code generation by model transformation, that is, the generation of a structured representation (model) of the target program instead of plain text. This approach enables the transformation of code after generation, which in turn enables the extension of the target language with features that allow better modularity in code generation rules. The technique can also be applied to ‘internal code generation’ for the translation of high-level extensions of a DSL to lower-level constructswithin the sameDSL using model-to-model transformations. This paper refines our earlier description of code generation by model transformation with an improved architecture for the composition of model-to-model normalization rules, solving the problem of combining type analysis and transformation. Instead of coarse-grained stages that alternate between normalization and type analysis, we have developed a new style of type analysis that can be integrated with normalizing transformations in a fine-grained manner. The normalization strategy has a simple extension interface and integrates non-local, context-sensitive transformation rules. We have applied the techniques in a realistic case study of domain-specific language engineering, i.e. the code generator for WebDSL, using Stratego, a high-level transformation language that integrates model-to-model, model-to-code, and code-to-code transformations.","transformation; transformation engineering; term rewriting; webapplication DSL; combination of analysis and transformation","en","journal article","Springer","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:cf63b683-9eaa-4b5f-8441-90fd4ad7e366","http://resolver.tudelft.nl/uuid:cf63b683-9eaa-4b5f-8441-90fd4ad7e366","On the conversion of functional models: Bridging differences between functional taxonomies in the modeling of user actions","Van Eck, D.","","2009","In this paper, I discuss a methodology for the conversion of functional models between functional taxonomies developed by Kitamura et al. (2007) and Ookubo et al. (2007). They apply their methodology to the conversion of functional models described in terms of the Functional Basis taxonomy into functional models described in terms of the Functional Concept Ontology taxonomy. I argue that this model conversion harbors two problems. One, a step in this model conversion that is aimed to handle differences in the modeling of user features consists of the removal of Functional Basis functions. It is shown that this removal can lead to considerable information loss. Two, some Functional Basis functions that I argue correspond to user functions, get re-interpreted as device functions in the model conversion. I present an alternative strategy that prevents information loss and information change in model conversions between the Functional Basis and Functional Concept Ontology taxonomies.","engineering design; functional modeling; knowledge exchange; user actions","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:a52d92e4-c560-4e33-add9-4ea2d382f9e1","http://resolver.tudelft.nl/uuid:a52d92e4-c560-4e33-add9-4ea2d382f9e1","Engine Power Effects on Support Interference","Horsten, B.J.C.; Veldhuis, L.L.M.","","2009","Renewed interest in propeller propulsion on aircraft configurations combined with higher propeller loads lead to the question how the effects of the propulsion on model support disturbances should be accounted for. In this paper, the determination of engine power effects on support interference of sting-mounted models is demonstrated by a measurement on a four-engine turboprop aircraft. CFD results on a more generic model are presented in order to clarify the possible mechanism behind engine power effects on support interference. The engine slipstream induces a local change in angle of sideslip at the model sting thereby influencing the sting near-field and far-field effects. Whether or not the net result of these changes in the disturbance pattern leads to a significant engine power effect depends on the configuration of the wind tunnel model and the test setup.","CFD; engine power effects; measurements; support interference","en","conference paper","World Academy of Science, Engineering and Technology","","","","","","","","Aerospace Engineering","Aerodynamics & Wind Energy","","","",""
"uuid:5da401ab-6257-42a2-a5a7-b8fddededab4","http://resolver.tudelft.nl/uuid:5da401ab-6257-42a2-a5a7-b8fddededab4","Development of engineered cementitious composites with limestone powder and blast furnace slag","Zhou, J.; Qian, S.; Sierra Beltran, M.G.; Ye, G.; Van Breugel, K.; Li, V.C.","","2009","Nowadays limestone powder and blast furnace slag (BFS) are widely used in concrete as blended materials in cement. The replacement of Portland cement by limestone powder and BFS can lower the cost and enhance the greenness of concrete, since the production of these two materials needs less energy and causes less CO2 emission than Portland cement. Moreover, the use of limestone powder and BFS improves the properties of fresh and hardened concrete, such as workability and durability. Engineered cementitious composites (ECC) is a class of ultra ductile fiber reinforced cementitious composites, characterized by high ductility, tight crack width control and relatively low fiber content. The limestone powder and BFS are used to produce ECC in this research. The mix proportion is designed experimentally by adjusting the amount of limestone powder and BFS, accompanied by four-point bending test and uniaxial tensile test. This study results in an ECC mix proportion with the Portland cement content as low as 15% of powder by weight. This mixture, at 28 days, exhibits a high tensile strain capacity of 3.3%, a tight crack width of 57 lm and a moderate compressive strength of 38 MPa. In order to promote a wide use of ECC, it was tried to simplify the mixing of ECC with only two matrix materials, i.e. BFS cement and limestone powder, instead of three matrix materials. By replacing Portland cement and BFS in the aforementioned ECC mixture with BFS cement, the ECC with BFS cement and limestone powder exhibits a tensile strain capacity of 3.1%, a crack width of 76 lm and a compressive strength of 40 MPa after 28 days of curing.","engineered cementitious composites; tensile strain capacity; limestone powder; blast furnace slag; blast furnace cement","en","journal article","Springer","","","","","","","","Civil Engineering and Geosciences","Design and Construction","","","",""
"uuid:88db4b2a-e60b-415c-9265-fbdc6c40c0ea","http://resolver.tudelft.nl/uuid:88db4b2a-e60b-415c-9265-fbdc6c40c0ea","Flowchart-assisted function analysis of products to support teaching of the exact sciences","Van der Vegte, W.F.; Van Breemen, E.J.J.","","2009","To reintroduce function analysis into the curriculum of Industrial Design Engineering (IDE), we developed a systematic approach suitable for interaction-intensive products. By strengthening the link between high-level design considerations and exact-science-based engineering calculations, our goal was to make the students more aware of the relevance of the exact sciences for designers. We started out from the problem that conventional function analysis approaches are difficult to apply to products interacting with users, while the user-oriented approaches that have come to replace function analysis in our curriculum do not easily connect to engineering aspects. The proposed approach involves a procedure to extract functions from the process tree that our students commonly use in design projects, and which allows mapping of transformations performed by the user to functions of the product. Putting functions on a gradual scale from ‘good’ to ‘bad’ points out directions for reconsideration. The approach is ‘open’: established methods for idea generation based on functions, and for configuration and analysis of transformation processes can be used in combination. It was embedded into a new, recently developed engineering-oriented course. Student evaluations have shown that the new course more effectively communicates the relevance of exact sciences than previously taught courses did. In the near future, our plan is to make the approach suitable for application in design projects. Another aspect to be addressed in future work is assessing the impact of our approach on the competencies that our students are developing.","function analysis; interactive products; industrial design engineering; education","en","conference paper","The Design Society","","","","","","","","Industrial Design Engineering","","","","",""
"uuid:7eb4fc7b-7def-43a5-ae7f-612bad7c86a9","http://resolver.tudelft.nl/uuid:7eb4fc7b-7def-43a5-ae7f-612bad7c86a9","System and Actor Perspectives on Sociotechnical Systems","De Bruijn, J.A.; Herder, P.M.","","2009","This paper addresses the complexity of analyzing and designing sociotechnical systems: systems that involve both complex physical-technical systems and networks of interdependent actors. It is shown that, although a hard system perspective and an actor perspective differ greatly in terms of terminology, methods, and applicability, they also show surprisingly many similarities. By building upon the similarities and differences of the two dominant perspectives, this paper then goes on to show that the modeling and intervention possibilities in both perspectives differ to a great extent. The emerging systems-of-systems discipline generally calls for an ldquointegrationrdquo of both perspectives in order to model and design these complex sociotechnical systems, but in this paper, it is argued and shown that full integration is not the preferred way to go. Instead, the emerging discipline should strive to facilitate the use of both perspectives alongside each other in a sensible way and, thereby, not discard the strengths of either perspective.","actor networks; complex systems; design; engineering systems; systems engineering; systems of systems","en","journal article","IEEE","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:156d9798-459e-4fd6-a857-b1c24bda8706","http://resolver.tudelft.nl/uuid:156d9798-459e-4fd6-a857-b1c24bda8706","A Rawlsian Approach to Distribute Responsibilities in Networks","Doorn, N.","","2009","Due to their non-hierarchical structure, socio-technical networks are prone to the occurrence of the problem of many hands. In the present paper an approach is introduced in which people’s opinions on responsibility are empirically traced. The approach is based on the Rawlsian concept of Wide Reflective Equilibrium (WRE) in which people’s considered judgments on a case are reflectively weighed against moral principles and background theories, ideally leading to a state of equilibrium. Application of the method to a hypothetical case with an artificially constructed network showed that it is possible to uncover the relevant data to assess a consensus amongst people in terms of their individual WRE. It appeared that the moral background theories people endorse are not predictive for their actual distribution of responsibilities but that they indicate ways of reasoning and justifying outcomes. Two ways of ascribing responsibilities were discerned, corresponding to two requirements of a desirable responsibility distribution: fairness and completeness. Applying the method triggered learning effects, both with regard to conceptual clarification and moral considerations, and in the sense that it led to some convergence of opinions. It is recommended to apply the method to a real engineering case in order to see whether this approach leads to an overlapping consensus on a responsibility distribution which is justifiable to all and in which no responsibilities are left unfulfilled, therewith trying to contribute to the solution of the problem of many hands.","responsibility; problem of many hands; Wide Reflective Equilibrium; procedural ethics; engineering ethics; socio-technical networks","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:3483724d-ab48-41b9-95c0-0f6bbbd99675","http://resolver.tudelft.nl/uuid:3483724d-ab48-41b9-95c0-0f6bbbd99675","3, 2, 1, Launch!","De Kat, R.; Saunders-Smits, G.N.","","2009","It is important that young people who chose to pursue a degree in engineering stick with their choice. Unfortunately students often loose their motivation during their first year. This paper gives an example of how the Faculty of Aerospace Engineering of Delft University in The Netherlands manages to keep a large number of freshmen motivated and at the same time acquaint them with the wonderful world of aerospace engineering through the design, build, launch and analysis of PET bottle based water-rockets.","project education; water-rocket; aerospace engineering; freshmen retention","en","conference paper","Delft University of Technology","","","","","","","","Aerospace Engineering","Aerodynamics & Wind Energy","","","",""
"uuid:d8ed32c8-a1da-43ba-a4df-9c0eddc1437d","http://resolver.tudelft.nl/uuid:d8ed32c8-a1da-43ba-a4df-9c0eddc1437d","Evaluating Dynamic Analysis Techniques for Program Comprehension","Cornelissen, S.G.M.","Van Deursen, A. (promotor); Zaidman, A.E. (promotor)","2009","Program comprehension is an essential part of software development and software maintenance, as software must be sufficiently understood before it can be properly modified. One of the common approaches in getting to understand a program is the study of its execution, also known as dynamic analysis. While many such approaches have been proposed in the literature, their empirical evaluation is often missing or inconclusive, and their added values to existing solutions are seldomly quantified. This dissertation aims to characterize, and extend upon, the existing work on program comprehension through dynamic analysis. A strong emphasis in our research is put on empirical evaluation. To structure the current state of the art and to identify research opportunities, we first conduct a systematic survey of all publications on this topic in the past decades. We then propose both a traditional and a more advanced visualization technique, experiment with the necessary abstraction techniques, and provide tool implementations. Our approaches are validated through extensive case studies and a controlled experiment. Finally, we conclude with a set of recommendations for future directions.","software maintenance; software understanding; reverse engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Softeware Technology","","","",""
"uuid:c9f748aa-d755-45b4-91db-f1daf64a8c58","http://resolver.tudelft.nl/uuid:c9f748aa-d755-45b4-91db-f1daf64a8c58","The Brittleness of Unbundled Train Systems: Crumbling Operational Coping Strategies","Steenhuisen, B.M.; De Bruijne, M.L.C.","","2009","This paper reports on the current status of the restructured Dutch rail sector. We empirically studied the strategies traffic controllers display to cope with daily value-conflicts in rail operations, at infrastructure manager ProRail and train operating company NS. We use a new framework to identify types of coping behavior. The findings are put in a broader perspective and related to literature on the organization of large complex socio-technical systems. In conclusion, we suggest what to make of the current coping strategies and the changed complexity of managing train systems. Current developments seem to raise the level of system performance but ignore the operational context of coping, making the train system more brittle on the long term.","coupling; engineering systems; coping strategies; unbundling utility sectors","en","conference paper","","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:6bcb6aa4-2a0f-4ca2-93cb-e2fe7abdbd41","http://resolver.tudelft.nl/uuid:6bcb6aa4-2a0f-4ca2-93cb-e2fe7abdbd41","Ecological Approach to Pilot Terrain Awareness","Borst, C.","Mulder, J.A. (promotor); Mulder, M. (promotor)","2009","The upgrade of the flight deck instruments from electro-mechanical dials and gauges towards computer-driven systems and interfaces was a necessary step to accommodate the increasing demands in flight technical performance and safety. The upgrade was a relatively slow process, however, where new systems were developed and installed as soon as the technology was available. As a result, many systems are not always well integrated in terms of presenting information. Together with the increasing amount of automation, the flight deck has become prone to issues such as information ambiguities and misunderstandings between the pilot and the (automated) avionic systems. This phenomenon is commonly labeled as a lack of ""situation awareness"" (SA) and has become a new cause for accidents. That is, pilots are unaware sometimes of the current flight situation, a situation that in itself may be caused by the automation. A recent example of this phenomenon is the Turkish Airlines accident near Schiphol on February 25 2009. The focus of this thesis is on aircraft terrain avionics, such as the Terrain Awareness Warning System (TAWS) and the Synthetic Vision System (SVS), that form a typical illustration of the evolution process and its issue regarding SA. The work in this thesis aimed to identify and address the missing information that would span the information gaps between the SVS and the TAWS to benefit pilot SA. The Ecological Interface Design (EID) framework was explored to accomplish this goal. EID was originally developed for the process industry (like nuclear power plants) and is therefore a rather novel approach in the field of flight deck design. The results of experimental evaluations indicated that pilots managed to benefit from the ecological interface enhancements to successfully and safely deal with hazardous terrain conflicts, even when encountering unanticipated events. It was found that the ecological interfaces made pilots more aware of the aircraft capabilities and much more actively involved in the decision-making loop to prevent fatal mishaps.","ecological interface design; cognitive systems engineering; flight displays; situation awareness; aviation","en","doctoral thesis","","","","","","","","","Aerospace Engineering","Control and Simulation","","","",""
"uuid:36c205fa-181c-44be-8b4e-2ba705e1c640","http://resolver.tudelft.nl/uuid:36c205fa-181c-44be-8b4e-2ba705e1c640","6-flow reactor: Catalyst testing in a multiphase-parallel packed-microreactor system","Herk, D. van","Moulijn, J.A. (promotor); Kreutzer, M.T. (promotor)","2009","This thesis deals with the design and operation of a multiple-parallel powder-packed reactor with continuous gas and liquid flows for kinetic tests. The reactor design is discussed in detail. Subsequently, axial dispersion in a multiphase packed microreactor is treated. Also, it is described how to minimise segregation during the loading of a catalyst-diluent powder mixture in these reactors.The kinetic tests, used as validation reaction, are hydrotreatment reactions to make fuels more environmentally friendly.","Continuous micro reactors; Powder catalyst loading; High-throughput experimentation; Hydro-dearomatisation; Chemical engineering; Catalysis; Kinetics","en","doctoral thesis","","","","","","","","2009-05-13","Applied Sciences","Catalysis Engineering","","","",""
"uuid:ef0decdb-f710-4c89-8c32-a8e452926632","http://resolver.tudelft.nl/uuid:ef0decdb-f710-4c89-8c32-a8e452926632","A Case Study: Application of the Systems Engineering Modeling in the early phases of a Complex Space System Project","Bone, M.; Cloutier, R.L.; Gill, E.K.A.; Verma, D.","","2009","There is increased recognition of the role of systems engineering in reducing the risk (technical, cost, and schedule) on complex space systems development and integration projects. A number of international systems engineering standards have been published in the last five years (ISO 15288, IEEE 1220, and EIA 632). Closer to the space domain, NASA recently updated and finalized the NASA Systems Engineering Processes and Requirements guidelines (NPR 7123.1 and NPR 7120.5). Figure 1 represents an encapsulated perspective on the key systems engineering processes and their dependencies are articulated in the new NASA NPR 7123.1. The NASA acquisition framework (Figure 2) represents their recursive (across levels) and iterative (within a level) approach to the SE process, and includes milestones and reviews, as well as updates to those events. This paper will focus on the early phases of the systems engineering process. This represents the first two System Design Processes of Figure 1, and the Pre-Systems Acquisition Phase – the Pre-Phase A, Phase A and Phase B in Figure 2. The paper will walk through a case study of a space system from the initial problem statement to defining the architectural technical risk to the program. The case study will show how early system engineering tools such as User Scenarios, Quality Function Deployment, and selection matrixes can be used in the initial system decisions to satisfy the NPR process. Then Systems Engineering Modeling will be illustrated in the context of a space systems case study [2]. Unique concepts such as active and passive stakeholders, and stakeholder capabilities and characteristics will be articulated to reduce the risk of misalignment between stakeholder expectations and technical system requirements. A framework for articulating a defined space mission into a set of well expressed and aligned technical requirements will be presented that satisfies the NPR process.","System Engineering Process; milestone; modeling; Space System; NPR","en","conference paper","Research School of Systems Engineering, Loughborough University","","","","","","","","Aerospace Engineering","Space Engineering","","","",""
"uuid:4dc692f2-47ca-4724-9b9f-f75f484db22d","http://resolver.tudelft.nl/uuid:4dc692f2-47ca-4724-9b9f-f75f484db22d","Traffic engineering and quality of service in the internet","Fu, B.","Van Mieghem, P.F.A. (promotor)","2009","","traffic engineering; quality of service","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:cfe89c67-35a0-420f-8f80-a30cfcdffe84","http://resolver.tudelft.nl/uuid:cfe89c67-35a0-420f-8f80-a30cfcdffe84","What has to be learnt for sustainability? A comparison of bachelor engineering education competences at three European universities","Segalas, J.; Ferrer-Balas, D.; Svanström, M.; Lundqvist, U.; Mulder, K.F.","","2009","In a period of harmonisation of the higher education system in Europe, a question is if also learning about sustainability at the universities is converging and what advantages this may have. This paper is an effort to present and advance the work on describing desired sustainability competences for engineering Bachelor graduates in three technical universities (Chalmers in Sweden, DUT in The Netherlands and UPC-Barcelona in Spain) using the European Higher Education Area (EHEA) descriptors. The paper also sheds light on whether there is conformity or not in desired sustainability competences (or in how sustainable development (SD) competences are handled) at the three universities. For universities outside the EHEA, this paper gives hints on the type of sustainability competences that will be required from their first-cycle graduates should they want to continue with second-cycle studies within the EHEA. The results show that the three universities follow a similar pattern in the classification of the competences (Knowledge and understanding, Skills and abilities, and Attitudes) and that there are minor divergences with respect to the list of competences and the levels of learning that Bachelor students should have when graduating. Definition of competences is an area that needs development, and this paper is part of a learning process for the three universities. This study shows that there is improvement potential for all three universities when it comes to being explicit and exact in the description of the desired SD learning.","Sustainability; Engineering; Education; Competences; Europe","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:6879a75b-ac5c-4ebd-b4ac-d958fa03003a","http://resolver.tudelft.nl/uuid:6879a75b-ac5c-4ebd-b4ac-d958fa03003a","System-Theoretical Model Reduction for Reservoir Simulation and optimization","Markovinovic, R.","Jansen, J.D. (promotor)","2009","This thesis is concerned with low-order modelling of heterogeneous reservoir systems for the purpose of efficient simulation and optimization of flooding processes with multiple injection and production (smart) wells. Typically, one is initially equipped with a physics-based ('white-box') model consisting of O(103-106) equations and parameters representing a (coupled) system of discretized PDEs defined on a geometric grid. The model-order reduction (MOR) methodology undertaken in this research is fundamentally different from the traditional, 'grid-coarsing' approximation methods, in that no coarse-grid approximation of the fine-grid problem is employed at all. Instead, the reduced-order models are here based on 'system-theoretic' and dynamically intrinsic properties of the fine-scale system. In single-phase flow problems that can be modelled as linear time-invariant state-space systems these properties are, e.g., the system's transfer function in the Laplace domain, the eigenstructure of the system matrix, or controllability and observability of the (particular state-space realization of the) system. For multi-phase flow problems resulting in nonlinear state-space models, intrinsic information needs to be sought in data obtained by simulating the fine-scale model. The contribution of this thesis can be divided into three themes: 1) Standard 'projection-based' MOR: assessment of the performance of modal truncation, singular perturbation, balanced truncation, transfer function moments maching (inc. Krylov-subspaces), and proper orthogonal decomposition (POD), 2) Acceleration of solving the fine-scale problem: use of MOR as a 'shadow simulation' to determine an improved fine-scale initial guess, and 3) Acceleration of waterflooding optimization: use of POD in the inner-loop of an adjoint-based optimization scheme.","petroleum; reservoir engineering; systems and control theory; model reduction; simulation-optimization; iterative numerical analysis","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:967e3f1d-7caf-4fa7-8f95-42bf1b9245a8","http://resolver.tudelft.nl/uuid:967e3f1d-7caf-4fa7-8f95-42bf1b9245a8","Implementing the Netherlands Code of Conduct for Scientific Practice: A Case Study","Schuurbiers, D.; Osseweijer, P.; Kinderlerer, J.","","2009","Widespread enthusiasm for establishing scientific codes of conduct notwithstanding, the utility of such codes in influencing scientific practice is not self-evident. It largely depends on the implementation phase following their establishment—a phase which often receives little attention. The aim of this paper is to provide recommendations for guiding effective implementation through an assessment of one particular code of conduct in one particular institute. Based on a series of interviews held with researchers at the Department of Biotechnology of Delft University of Technology, this paper evaluates how the Netherlands Code of Conduct for Scientific Practice is received by those it is supposed to govern. While respondents agreed that discussion of the guiding principles of scientific conduct is called for, they did not consider the code as such to be a useful instrument. As a tool for the individual scientific practitioner, the code leaves a number of important questions unanswered in relation to visibility, enforcement, integration with daily practice and the distribution of responsibility. Recommendations are provided on the basis of these questions. There is more at stake than merely holding scientific practitioners to a proper exercise of their duties; implementation of scientific society codes of conduct also concerns the further motives and value commitments that gave rise to their establishment in the first place.","Code of conduct; Science and engineering ethics; Responsible conduct of research; Research integrity; Moral responsibility","en","journal article","Springer","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:3beba418-24d5-4bd3-9852-6ba9dc9e26f2","http://resolver.tudelft.nl/uuid:3beba418-24d5-4bd3-9852-6ba9dc9e26f2","Model driven construction and costumization of modeling and simulation web applications","Levytskyy, A.","Koppelaar, H. (promotor)","2009","","modeling and simulation (M&S); web-based environment; conceptual framework; efficient customization; model-driven engineering (MDE)","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:9c21a12a-b9b3-4bf1-a0d5-6321fe3e644e","http://resolver.tudelft.nl/uuid:9c21a12a-b9b3-4bf1-a0d5-6321fe3e644e","CONTROL OF PROPELLER CAVITATION DURING A DECELERATION","Vrijdag, A.","Hopman, J.J. (advisor)","2009","","resistance & propulsion; propulsion control system; cavitation; deceleration; frigate; diesel engine; acoustic signatare management","","conference paper","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:8061b9b5-28c2-4fa2-ada2-5aa3876b2fbf","http://resolver.tudelft.nl/uuid:8061b9b5-28c2-4fa2-ada2-5aa3876b2fbf","A Design Approach for Collaboration Processes: A Multi-Method Design Science Study in Collaboration Engineering","Kolfschoten, G.L.; De Vreede, G.J.","","2009","Collaboration Engineering is an approach for the design and deployment of repeatable collaboration processes that can be executed by practitioners without the support of collaboration professionals such as facilitators. A critical challenge in Collaboration Engineering concerns how the design activities have to be executed and which design choices have to be made to create a process design. We report on a four year design science study, in which we developed a design approach for Collaboration Engineering thatincorporates existing process design methods, pattern based design principles, and insights from expert facilitators regarding design challenges and choices. The resulting approach was evaluated and continuously improved in four trials with 37 students. Our findings suggest that this approach is useful to support the design of repeatable collaboration processes. Our study further serves as an example of how a design approach can be developed and improved following a multi-method design science approach.","collaboration engineering; design science; facilitation; GSS; pattern language","en","journal article","M.E. Sharpe","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:2bb9b84f-1c9b-4a22-ac0f-f3333607dfd0","http://resolver.tudelft.nl/uuid:2bb9b84f-1c9b-4a22-ac0f-f3333607dfd0","Exposing the Hidden-Web Induced by Ajax","Mesbah, A.; Van Deursen, A.","","2008","AJAX is a very promising approach for improving rich interactivity and responsiveness of web applications. At the same time, AJAX techniques increase the totality of the hidden web by shattering the metaphor of a web ‘page’ upon which general search engines are based. This paper describes a technique for exposing the hidden web content behind AJAX by automatically creating a traditional multi-page instance. In particular we propose a method for crawling AJAX applications and building a state-flow graph modeling the various navigation paths and states within an AJAX application. This model is used to generate linked static HTML pages and a corresponding Sitemap. We present our tool called CRAWLJAX which implements the concepts discussed in this paper. Additionally, we present a case study in which we apply our approach to two AJAX applications and elaborate on the obtained results.","ajax; hidden web; crawling ajax; search engine accessibility; web engineering","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Computer Technology","","","",""
"uuid:18224df8-3d4a-4993-8280-8a8a77156534","http://resolver.tudelft.nl/uuid:18224df8-3d4a-4993-8280-8a8a77156534","A Component- and Push-based Architectural Style for Ajax Applications","Mesbah, A.; Van Deursen, A.","","2008","Preprint of article published in: Journal of Systems and Software (Elsevier), 81 (12), 2008; doi:10.1016/j.jss.2008.04.005 A new breed of web application, dubbed ajax, is emerging in response to a limited degree of interactivity in large-grain stateless Web interactions. At the heart of this new approach lies a single page interaction model that facilitates rich interactivity. Also push-based solutions from the distributed systems are being adopted on the web for ajax applications. The field is, however, characterized by the lack of a coherent and precisely described set of architectural concepts. As a consequence, it is rather difficult to understand, assess, and compare the existing approaches. We have studied and experimented with several ajax frameworks trying to understand their architectural properties. In this paper, we summarize four of these frameworks and examine their properties and introduce the spiar architectural style which captures the essence of ajax applications. We describe the guiding software engineering principles and the constraints chosen to induce the desired properties. The style emphasizes user interface component development, intermediary delta-communication between client/server components, and push-based event notification of state changes through the components, to improve a number of properties such as user interactivity, user-perceived latency, data coherence, and ease of development. In addition, we use the concepts and principles to discuss various open issues in ajax frameworks and application development.","ajax; web architectural style; web engineering; single page interface; rich internet application","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Computer Technology","","","",""
"uuid:4900fa13-4b03-422e-91ea-dda1958c3855","http://resolver.tudelft.nl/uuid:4900fa13-4b03-422e-91ea-dda1958c3855","Crawling AJAX by Inferring User Interface State Changes","Mesbah, A.; Bozdag, E.; Van Deursen, A.","","2008","Preprint of paper published in: ICWE 2008 - 8th International Conference on Web Engineering, 14-18 July 2008; doi:10.1109/ICWE.2008.24 AJAX is a very promising approach for improving rich interactivity and responsiveness of web applications. At the same time, AJAX techniques shatter the metaphor of a web ""page"" upon which general search crawlers are based. This paper describes a novel technique for crawling AJAX applications through dynamic analysis and reconstruction of user interface state changes. Our method dynamically infers a state-flow graph modeling the various navigation paths and states within an AJAX application. This reconstructed model can be used to generate linked static pages. These pages could be used to expose AJAX sites to general search engines. Moreover, we believe that the crawling techniques that are part of our solution have other applications, such as within general search engines, accessibility improvements, or in automatically exercising all user interface elements and conducting state-based testing of AJAX applications. We present our open source tool called CRAWLJAX which implements the concepts discussed in this paper. Additionally, we report a case study in which we apply our approach to a number of representative AJAX applications and elaborate on the obtained results.","ajax; crawler; search engine","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Computer Technology","","","",""
"uuid:0b76b7ad-17d7-47f7-8aab-b19207f9577a","http://resolver.tudelft.nl/uuid:0b76b7ad-17d7-47f7-8aab-b19207f9577a","Code Generation by Model Transformation: A Case Study in Transformation Modularity","Hemel, Z.; Kats, L.C.L.; Visser, E.","","2008","Preprint of paper published in: Theory and Practice of Model Transformations (ICMT 2008), Lecture Notes in Computer Science 5063; doi:10.1007/978-3-540-69927-9_13 The realization of model-driven software development requires effective techniques for implementing code generators for domain-specific languages. This paper identifies techniques for improving separation of concerns in the implementation of generators. The core technique is code generation by model transformation, that is, the generation of a structured representation (model) of the target program instead of plain text. This approach enables the transformation of code after generation, which in turn enables the extension of the target language with features that allow better modularity in code generation rules. The technique can also be applied to ‘internal code generation’ for the translation of high-level extensions of a DSL to lower-level constructs within the same DSL using model-to-model transformations. This paper refines our earlier description of code generation by model transformation with an improved architecture for the composition of model-to-model normalization rules, solving the problem of combining type analysis and transformation. Instead of coarse-grained stages that alternate between normalization and type analysis, we have developed a new style of type analysis that can be integrated with normalizing transformations in a fine-grained manner. The normalization strategy has a simple extension interface and integrates non-local, context-sensitive transformation rules. We have applied the techniques in a realistic case study of domain-specific language engineering, i.e. the code generator for WebDSL, using Stratego, a high-level transformation language that integrates model-to-model, model-to-code, and code-to-code transformations.","transformation; transformation engineering; term rewriting; webapplication DSL; combination of analysis and transformation","en","lecture notes","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Computer Technology","","","",""
"uuid:e2d205a5-f89a-405e-9861-88550db946f4","http://resolver.tudelft.nl/uuid:e2d205a5-f89a-405e-9861-88550db946f4","A formal ontological perspective on the behaviors and functions of technical artifacts","Borgo, S.; Carrara, M.; Garbacz, P.; Vermaas, P.E.","","2008","In this paper we present a formal characterization of the engineering concepts of behavior and function of technical artifacts. We capture the meanings that engineers attach to these concepts by formalizing, within the formal ontology DOLCE, the five meanings of artifact behavior and the two meanings of function that Chandrasekaran and Josephson identified in 2000 within the functional representation approach.We begin our formalization by reserving the term “behavior” of a technical artifact as “the specific way in which the artifact occurs in an event.” This general notion is characterized formally, and used to provide definitions of actual behaviors of artifacts, and the physically possible and physically impossible behaviors that rational agents believe that artifacts have. We also define several other notions, for example, input and output behaviors of artifacts, and then show that these ontologically characterized concepts give a general framework in which Chandrasekaran and Josephson’s meanings of behavior can be explicitly formalized. Finally we show how Chandrasekaran and Josephson’s two meanings of artifact functions, namely, device-centric and environment-centric functions, can be captured in DOLCE via the concepts of behavioral constraint and mode of deployment of an artifact. A more general goal of this work is to show that foundational ontologies are suited to the engineering domain: they can facilitate information sharing and exchange in the various engineering domains by providing concept structures and clarifications that make explicit and precise important engineering notions. The meanings of the terms “behavior” and “function” in domains like designing, redesigning, reverse engineering, product architecture, and engineering knowledge bases are often ambiguous or overloaded. Our results show that foundational ontologies can accommodate the variety of denotations these terms have and can explain their relationships.","Behavior; Engineering; Formal Ontology; Function; Technical Artifact","en","journal article","Cambridge University Press","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:4cbc0702-befa-40b5-9f75-f41fb918b429","http://resolver.tudelft.nl/uuid:4cbc0702-befa-40b5-9f75-f41fb918b429","Three challenges, four pitfalls and five actions when teaching conceptual modelling","Frantzeskaki, N.; De Haan, A.; Kolfschoten, G.L.; Walker, W.","","2008","Modelling is of substantial use in policy analysis. Since policy analysis tries to facilitate decision making of complex multi-actor problems under uncertain circumstances, it needs to rationalize and simplify reality. This is the major challenge of doing policy analysis and especially modelling. The model as an abstract representation of the real system, should contain all (and preferably only) the relevant aspects of the real problem field. To acquire modelling skills requires lots of experience and training. We notice in our modelling courses that students have a distinct set of pitfalls when they try to model: abstraction pitfalls, labelling pitfalls, conceptual pitfalls, and analysis communication pitfalls. In this paper we give clear descriptions of each so that they are more easily recognisable. There are five recommended alternatives for which we provide concrete descriptions on how they are applied in practice. We labelled them as follows: (1) reiteration, (2) renaming or remaking, (3) keeping the big picture in mind, (4) returning to the roots, and (5) checking and doublechecking. Our systematic way of describing the pitfalls, including the potential solutions, should make it easier for teachers and supervisors to guide junior modellers in building better models for multi-actor systems.","modelling; engineering education; working groups; multi actor systems; collaborative learning","en","conference paper","International Association of Technology, Education and Development (IATED)","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:347320f4-fe43-43a0-a2d5-46a370ef07d2","http://resolver.tudelft.nl/uuid:347320f4-fe43-43a0-a2d5-46a370ef07d2","A new technology for the reduction of particulate matter from diesel engines in ships","Van Rens, G.L.M.A.","Stapersma, D. (promotor); Witkamp, G.J. (promotor)","2008","In this thesis the focus is on the particulate matter reduction of ships, as ships contribute significantly to the particulate matter concentration in ambient air. Because the fuel of sea ships contains a lot of ash, the emitted particulate matter will also contain a lot of ash. In car and truck applications the soot filters are cleaned by burning the particulate matter off of the filter. However, ash will not be burned off and accumulates in the filter. In the case of high-ash loads, like sea ships, a soot filter is not applicable, because the filters cannot be cleaned properly. The goal of the research was to develop a technology to reduce particulate matter that is fuel insensitive. In this thesis such a technology is described, tested and simulated for high-ash applications. The patented technology is based on coating particulate matter with water, and subsequently capturing by an electrostatic precipitator (ESP). In the present experimental set-up this was a two-stage ESP, which has a robust construction and a reduced risk of physical contact between the electrodes at different potential. The water-coated particles will flow off the collection plates, therefore allowing continuous operation of the ESP. The water stream needs to be cleaned before it is discharged in the surface waters. The required cleaning technology, however, is similar to the cleaning technologies used in sea water scrubbers. It is proven that the technology is capable of removing 80% of particulate matter, including the fraction of particulate matter smaller than 1 micrometer in (mobility) diameter. It was found that the new technology was rather insensitive to particle size and is thus very suitable to remove sub-micron particles.","particulate matter; diesel engines; ships; fuel oil; esp","en","doctoral thesis","","","","","","","","","Mechanical Maritime and Materials Engineering","","","","",""
"uuid:c85e8096-48ad-47d6-944b-d9f99f358b5a","http://resolver.tudelft.nl/uuid:c85e8096-48ad-47d6-944b-d9f99f358b5a","Study of Delft aerospace alumni","Smits, G.N.","Gurdal, Z. (promotor); De Graaff, E. (promotor)","2008","This thesis reports on an alumni study of the Faculty Aerospace Engineering at Delft University of Technology to discover what the impact is of the degree in aerospace engineering on an alumnus' professional success and comment on what are important qualities for aerospace engineers to have in order to differentiate themselves from those with an average career. Based on a literature survey and feedback of an expert panel a list of 12 competencies, deemed important for the professional success of alumni, was developed. These competencies are: the ability to synthesize, analyticalskills, problem solving skills, people and operational management skills, oral and written communication skills,networking skills, broad technical knowledge, specialist technical knowledge, ability for life-long learning and the ability to work in teams. It was also discovered in literature that there are two principal career tracks of aerospace engineers: that of the engineering specialist and that of the engineering manager. The success definitions used were: level of job responsibility, salary with respect to work experience and salary with respect to work experience and level of job responsibility.The results of the questionnaire showed that the aerospace alumni do well and are very satisfied with their degree.The results of the survey showed that all 12 competencies were important to a certain degree for an alumnus' current job. No significant relationship however, was found, between the contribution of aerospace engineering to the competencies and professional success. Alumni also indicated that they deem themselves less capable in people and operational management skills as well as networking skills. The results also showed that having good specialist technical knowledge does contribute to more job responsibility but not necessarily to more salary. Furthermore it was found that the alumnis' ability in people and operational management skills have a positive influence on their professional success.The thesis also contains recommendation with regards to the implementation of the competencies in aerospace engineering curricula.","engineering education; higher education; aerospace engineering; alumni; success","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:991dc30d-aaf6-44f2-9f4f-b1f04533e7c9","http://resolver.tudelft.nl/uuid:991dc30d-aaf6-44f2-9f4f-b1f04533e7c9","Generic methods for aero-engine exhaust emission prediction","Shakariyants, S.A.","Van Buijtenen, J.P. (promotor)","2008","In the thesis, generic methods have been developed for aero-engine combustor performance, combustion chemistry, as well as airplane aerodynamics, airplane and engine performance. These methods specifically aim to support diverse emission prediction studies coupled with airplane and engine simulation. Models for the engine exhaust composition can be either selected from existing methods or composed from the algorithms for combustor performance and combustion chemistry produced in the thesis. The best application of this work is analysis of exhaust emissions under varying operating conditions representative of current civil transport airplanes powered by turbofan engines - the main body of today's air transport. Various objectives can be pursued in such analysis: Emission footprints of both single airplane operating phases and complete missions can be investigated. The analysis may lead to comparison and optimization of operating practices from the viewpoint of emission production. This all may help better quantify the environmental impact of existing air transport technology, as well as develop and evaluate operational emission mitigation measures. Practices which conflict with the minimization of environmental impact can be articulated.","gas turbines; aero-enginines; aircraft engines; exhaust emissions; emission modeling","en","doctoral thesis","","","","","","","","","Mechanical Maritime and Materials Engineering","","","","",""
"uuid:33d247e8-d493-4451-82ac-eacb5d9f4ff0","http://resolver.tudelft.nl/uuid:33d247e8-d493-4451-82ac-eacb5d9f4ff0","Controllability, observability and identifiability in single-phase porous media flow","Zandvliet, M.J.; Van Doren, J.F.M.; Bosgra, O.H.; Jansen, J.D.; Van den Hof, P.M.J.","","2008","Over the past few years, more and more systems and control concepts have been applied in reservoir engineering, such as optimal control, Kalman filtering, and model reduction. The success of these applications is determined by the controllability, observability, and identifiability properties of the reservoir at hand. The first contribution of this paper is to analyze and interpret the controllability and observability of single-phase flow reservoir models and to investigate how these are affected by well locations, heterogeneity, and fluid properties. The second contribution of this paper is to show how to compute an upper bound on the number of identifiable parameters when history matching production data and to present a new method to regularize the history matching problem using a reservoir’s controllability and observability properties.","reservoir engineering; controllability; observability; identifiability","en","journal article","Springer","","","","","","","","Civil Engineering and Geosciences","Petroleum Engineering","","","",""
"uuid:6d7a0418-d2ac-466e-9cfa-7d182486ff8c","http://resolver.tudelft.nl/uuid:6d7a0418-d2ac-466e-9cfa-7d182486ff8c","Component-Specific Usability Testing","Brinkman, W.P.; Haakma, R.; Bouwhuis, D.G.","","2008","This paper presents the results of a meta-analysis carried out on the results of six experiments to support the claim that component-specific usability measures are on average statistically more powerful than overall usability measures when comparing different versions of a part of a system. An increase in test effectiveness implies the need for fewer participants in usability tests that study different versions of a component. Three component-specific measures are presented and analyzed: an objective efficiency measure and two subjective measures, one about the ease-of-use and the other about the users’ satisfaction. Whereas the subjective measures are obtained with a questionnaire, the objective efficiency measure is based on the number of user messages received by a component. Besides describing the testing method, this paper also discusses the underlying principles such as layered interaction and multiple negative-feedback loops. The main contribution of the work described is the presentation of component-based usability testing as an alternative for traditional holistic-oriented usability tests. The former is more aligned with the component-based software engineering approach, helping engineers to select the most usable versions of a component","component-based software engineering (CBSE); software testing; usability testing; user-centered design methodology","en","journal article","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Mediamatics","","","",""
"uuid:158f5c7b-5b60-4636-beef-69007efe7986","http://resolver.tudelft.nl/uuid:158f5c7b-5b60-4636-beef-69007efe7986","Controlling enigneering-to-order processes in shipbuilding, a model-based approach","Coenen, J.M.G.","Nienhuis, U. (promotor)","2008","Engineering-to-Order processes in shipbuilding are characterised by their results: unique ships built on customer specification. A challenge is the control of such processes: the combination of complex technical solutions, a large quantity of specialist engineers of different parties, highly interrelated âconcurrentâ tasks, continuous exchange of information and also stochastic events make that current planning and management tools do not suffice. This research describes a first exploration in the field of modelling Engineering-to-Order processes, in order to obtain insight in fundamental process behaviour. This with the purpose to improve process control tools in the future. Innovative aspects of this research lie in the following fields: -detailed modelling of abstract engineering processes with their unique features -a fast configuration method for the generation of ship specific process models -integration of process diagrams for representation of models and simulation models -the introduction of simulation-based, stochastic planning in shipbuilding.","engineering-to-order; shipbuilding; simulation; planning; processes","en","doctoral thesis","","","","","","","","","Mechanical Maritime and Materials Engineering","","","","",""
"uuid:20b5a4b5-6419-4593-a668-48074982bcb3","http://resolver.tudelft.nl/uuid:20b5a4b5-6419-4593-a668-48074982bcb3","Model-based lifecycle optimization of well locations and production settings in petroleum reservoirs","Zandvliet, M.J.","Bosgra, O.H. (promotor); Jansen, J.D. (promotor)","2008","The coming years there is a need to increase production from petroleum reservoirs, and there is an enormous potential to do so by increasing the recovery factor. This is possible by making better use of recent technological developments, such as horizontal wells, downhole valves and sensors. However, actually making better use of these improved capabilities is difficult because of many open problems in reservoir management and production operations processes. Consequently, there is significant scope to increase the recovery factor of oil and gas fields by tailoring tools from the systems and control community to efficiently perform dynamic optimization of wells (e.g. number, locations) and their production settings (e.g. bottom-hole pressures, flow rates, valve settings) based on uncertain reservoir models, in the sense that they lead to good decisions while requiring limited time from the user. This thesis aims at developing these tools, and the main contributions are as follows. Many production setting optimization problems can be written as optimal control problems that are linear in the control. If the only constraints are upper and lower bounds on the control, these problems can be expected to have pure bang-bang optimal solutions. The adjoint method to derive gradients of a cost function with respect to production settings can be combined with robust optimization to efficiently compute settings that are robust against uncertainty in reservoir models. The gradients used in production setting optimization can be used to efficiently compute directions in which to iteratively improve upon an initial well configuration by surrounding the to-be-placed wells by pseudo wells (i.e. wells that operate at a negligible rate). The controllability and observability properties of single-phase flow reservoir model are analyzed. It is shown that pressures near wells in which we can control the flow rate or bottom-hole pressure are controllable, whereas pressures near wells in which we can measure the flow rate or bottom-hole pressure are observable. Finally, a new method of regularization in history matching is presented, based on this controllability and observability analysis.","petroleum; reservoir engineering; systems and control; optimization","en","doctoral thesis","","","","","","","","","Mechanical Maritime and Materials Engineering","","","","",""
"uuid:576da4a7-781c-4950-a36e-2366211022a7","http://resolver.tudelft.nl/uuid:576da4a7-781c-4950-a36e-2366211022a7","Renovation of idiomatic crosscutting concerns in embedded systems","Bruntink, M.","Van Deursen, A. (promotor); Klint, P. (promotor)","2008","Crosscutting concerns are phenomena that are present in almost any (embedded) software system. They arise if the implementation of a concern ""a requirement or design decision"" does not fit neatly into the modular decomposition of a software system. A crosscutting concern cannot be confined to a single modular unit and therefore becomes scattered across the system and tangled with other concerns. This thesis focuses on the specific class of idiomatic crosscutting concerns, which are crosscutting concerns that are idiomatic in the sense that they are implemented manually by applying an idiom, resulting in many similar pieces of source code. The approach taken is that of renovation, i.e., a step-wise improvement process aimed at easing the evolution of legacy software systems. The legacy software system that is studied in this thesis is the (embedded) control software of an ASML wafer scanner, a device used in the manufacturing process of integrated circuits. This software system consists of 15 million lines of C code. We study whether the use of AOP is beneficial compared to the idiomatic style of implementation used in the ASML software system.","crosscutting concerns; idioms; aspect-oriented programming; program analysis; program transformation; renovation; reengineering; reverse engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:035ff4f2-27f4-43eb-b6bd-314490ed5ac6","http://resolver.tudelft.nl/uuid:035ff4f2-27f4-43eb-b6bd-314490ed5ac6","Transcriptomics and quantitative physiology of ß-lactam producing Penicillium chrysogenum","Harris, D.M.","Pronk, J.T. (promotor)","2008","With an over 1000-fold improvement in specific productivity since its discovery, penicillin is one of the very successful examples of industrial biotechnology. Although classical strain improvement programmes have been a major contributor to this success, the wish for a more rational approach towards improvements has driven the work described in this thesis. As most ß-lactam biosynthesis routes share the first steps in their pathway, the production of penicillin-G in chemostat cultivations of P. chrysogenum has been chosen as a model system. Compared to common laboratory organisms such as bakers' yeast, the information on P. chrysogenum is relatively limited, which also reduces the range of possibilities for a rational approach. The majority of the work described in this thesis can therefore be assigned to the analysis phase of the metabolic engineering cycle. In the first half of the thesis more classical techniques are employed to investigate two important aspects of ß-lactam production: NADPH metabolism and the unexpectedly high energy demand of penicillin production. The work presented in the second half of this thesis was made possible by the availability of the genome sequence of P. chrysogenum. A whole series of transcriptome studies of chemostat based cultivations of P. chrysogenum was set up with the aim to identify key factors involved in penicillin production. Using this experimental design it was possible to explore transcriptional responses towards ß-lactam production and side chain catabolism at a genome-wide scale. Each of these studies has provided putative targets for metabolic engineering of ß-lactam production by Penicillium chrysogenum.","penicillium chrysogenum; penicillin transcriptomics; metabolic engineering; micro-array; ß-lactam; chemostat; phenylacetic acid","en","doctoral thesis","","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:f3c0ade4-80bf-4f86-a07a-4f86a29f653d","http://resolver.tudelft.nl/uuid:f3c0ade4-80bf-4f86-a07a-4f86a29f653d","An Integrated System to Manage Crosscutting Concerns in Source Code","Marin, A.M.","Van Deursen, A. (promotor)","2008","Evolution of software systems accounts for the largest part of their lifecycle and costs. Software engineers therefore, more often than developing new systems, work on complex, existing ones that they have to understand in order to modify them. Understanding such systems requires insight into the various concerns the systems implement, many of which have to be inferred from source code. Particularly challenging for software comprehension, and consequently, software evolution, are those concerns said to be crosscutting: implementation of such concerns lacks modularity and results in scattered and tangled code. The research presented in this thesis proposes an integrated approach to consistent comprehension, identification, documentation, and migration of crosscutting concerns in existing systems. This work is aimed at helping software engineers to more easily understand and manage such concerns in source code. As a final step of our approach, we also experiment with the refactoring of crosscutting concerns to aspect-oriented programming and reflect on the support provided by this new programming technique for improving modularization of concerns.","crosscutting concerns; concern (source code) modeling; source code queries; aspect mining; aspect-oriented programming; refactoring; software evolution; reverse engineering; program comprehension; software engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:129c631c-efdc-4b3f-b94d-41777d21d51e","http://resolver.tudelft.nl/uuid:129c631c-efdc-4b3f-b94d-41777d21d51e","Knowledge based engineering support for aircraft component design","Van der Laan, A.H.","Van Tooren, M.J.L. (promotor)","2008","","kbe; cost engineering","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:65ec884a-7132-4005-a07b-2300145da6b9","http://resolver.tudelft.nl/uuid:65ec884a-7132-4005-a07b-2300145da6b9","A studio based approach for business engineering and mobile services","Wang, Y.","Sol, H.G. (promotor)","2008","In today's world, organizations are becoming increasingly interested in using mobile technology as a means to adapt to the ever-changing environment. An important challenge that the organizations are facing is how to efficiently and effectively support business process carried out by their mobile workers in distributed environments. In the research presented in this dissertation, we examined mobility issues within the context of current organizations' engineering effort. We carried out inductive case studies that revealed the need for an approach that support the reality of mobile workers, and based on these findings we developed a simulation based support studio consisting of an approach and software suite. The support studio can be used to assist organizations to design mobile workforce solutions for the purpose of process performance improvement. We implemented the simulation suite in a prototype and demonstrated its usefulness through two testing case studies. Further, we carried out expert evaluation based on the three dimensions of usefulness, usability, and usage of the studio. We concluded that simulation can be considered to be an effective method of inquiry for improving the effectiveness of business engineering and mobile services in organizations. The studio based approach was considered to be effective in providing insight into the business processes that are enabled by mobile services, through the possibility of carrying out 'what-if' analysis with different scenarios without having to perform the actual implementation of the solution.","business engineering; mobile services; decision support; simulation and modeling","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:de72e000-1c1e-4dbe-83ec-a1aef880d60e","http://resolver.tudelft.nl/uuid:de72e000-1c1e-4dbe-83ec-a1aef880d60e","A knowledge based engineering approach to support automatic design of wind turbine blades","Chiciudean, T.G.; La Rocca, G.; van Tooren, M.J.L.","","2008","","multidisciplinary; design; integration; knowledge Based Engineering","en","conference paper","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:442b85cd-3a99-4703-a614-c67e95caab44","http://resolver.tudelft.nl/uuid:442b85cd-3a99-4703-a614-c67e95caab44","On the relevance of on-line traffic engineering","Fu, B.; Uhlig, S.","","2008","","traffic engineering; network provisioning; network design","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:9fdac7ea-bd42-49a7-8078-cbc9af9e35e6","http://resolver.tudelft.nl/uuid:9fdac7ea-bd42-49a7-8078-cbc9af9e35e6","Breakwaters and closure dams (2nd edition)","d'Angremond, K.; van Roode, F.; Verhagen, H.J.","","2008","","coastal engineering; breakwaters; closure dams","en","lecture notes","VSSD","978-90-6562-173-3","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:84eb9c01-2c1d-4db0-86d4-7c254e7a2bb5","http://resolver.tudelft.nl/uuid:84eb9c01-2c1d-4db0-86d4-7c254e7a2bb5","Service oriented concurrent engineering with hybrid teams using a multi-agent task environment","Berends, J.P.T.J.; van Tooren, M.J.L.","","2008","","Service Oriented Engineering; Multidisciplinary Design Optimisation: Design and Engineering Engine; Knowledge Based Engineering; Multi-agent Task Environment; Engineering Frameworks","en","conference paper","Springer Verlag","","","","","","","","Aerospace Engineering","","","","",""
"uuid:105e11ee-c5f9-47b1-beb3-e1836b0f5990","http://resolver.tudelft.nl/uuid:105e11ee-c5f9-47b1-beb3-e1836b0f5990","Application of a knowledge engineering process to support engineering design application development","van der Elst, S.W.G.; van Tooren, M.J.L.","","2008","","knowledge based engineering; DEE; knowledge engineering; agents; wiring harness","en","conference paper","Springer","","","","","","","","Aerospace Engineering","","","","",""
"uuid:f724734b-eab2-4e50-b697-92671479d87e","http://resolver.tudelft.nl/uuid:f724734b-eab2-4e50-b697-92671479d87e","Model-driven evolution of software architectures","Graaf, B.S.","van Deursen, A. (promotor)","2007","Software evolves continuously. As a consequence, software systems tend to become increasingly complex and, as such, more difficult to change. A software system's complexity is for a large part determined by its structure, or architecture. In this thesis we investigate how to reduce the risks and costs associated with the evolution of software architectures. Automation and abstraction are two basic software engineering techniques to deal with complexity. In this thesis we investigate the applicability of model-driven engineering, a new software development approach based on abstraction and automation, to support the evolution of software architectures. The main research question we address in this thesis is: ""How can evolution of software architectures be supported?"". Three subquestions related to industrial integration, software product lines, and automation further clarify the scope of our work. We first conducted a survey among several software development organisation to inventory the state-of-the-practice in software engineering technologies. Some trends we observed from this inventory include: the informal use modelling in industry, the use of product-line approaches, and the importance of the evolutionary aspect of software. Next, we investigated how to support four tasks related to software architecture evolution: evaluation, conformance checking, migration, and documentation. We aim to automate this support where possible. To this end, we employ model-driven software development technologies. For each of the software evolution tasks, we present a case study that investigates how that task can be supported. The informal use of modelling in industry calls for a normalisation step to enable the integration of evolution support in practice. Several chapters address the impact of the use of product-line approaches on the evolution support. Although the increased scope make such support more difficult to develop, the return on investment for the model-driven support is much improved. The model-driven evolution support follows a similar three-step pattern. First, a set of source models is preprocessed into a form suitable for the application of model transformations. Then, model transformations are applied that do the actual work, such as conformance checking or a migration. Finally, the resulting models are postprocessed in a resulting into a desired target form.","software engineering; model-driven engineering; software evolution; software architecture","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:9e8e2dae-639b-4fd6-b4bd-1318b37e60c2","http://resolver.tudelft.nl/uuid:9e8e2dae-639b-4fd6-b4bd-1318b37e60c2","A multi-body dynamics approach to a cable simulator for kites","Breukels, J.; Ockels, W.J.","","2007","For the purpose of ultimately building a fully dynamic simulation of kites, an investigation is launched into a viable model of the cable with which the kite is attached to the ground. In the model proposed in this paper, only the slow modes of motion are taken into account due to the fact that only the slow motions have a real effect on the flight characteristics of the kite. Fast vibrations have a low amplitude with little effect. Also, by taking out all the fast modes of motion, the time step for integration can remain fairly large, speeding up the calculation process. Of special interest in the model is the damping which consists of aerodynamic damping and material-based damping. The relation between these two forms of damping is investigated. Verification of the model is done through comparison with analytical and real-life measured data. The resulting model is simulated in MSC ADAMS. It is shown that the aerodynamic damping is of prime interest because it dampens the slower motions. Material damping dampens mostly the fast vibrations.","kites; cable; simulation; dynamic modelling; model development; applications of simulation in engineering","en","conference paper","","","","","","","","","Aerospace Engineering","Aerospace Design, Integration and Operations","","","",""
"uuid:020f19de-1b19-4f71-89b4-3a85d81ec9bc","http://resolver.tudelft.nl/uuid:020f19de-1b19-4f71-89b4-3a85d81ec9bc","Essential perspectives for Design for Environment: Experiences from the electronics industry","Boks, C.B.; Stevels, A.L.N.","","2007","Consolidation of knowledge, information and experiences in application of Design for Environment principles is done at various levels, ranging from easy to understand slogans to design guidelines, and even to tailor-made solutions. This brings about that dissemination of this knowledge should be done taking carefully the intended audience and relevant contexts into account– especially when dissemination is done in the form of ‘principles’, which are usually presented without context at all. It is discussed in this paper how interpretations of consolidating principles can lead to misinterpretations and even counterproductive actions. At least three principles can be identified that should be taken into account when disseminating DFE knowledge, discussing 1) different perspectives of what is environmentally friendly, 2) the life-cycle perspective, and 3) the integration of environmental and economical considerations.","green engineering; ecodesign; design for environment; industrial; application; life cycle assessment","en","journal article","Taylor & Francis","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:767e71bd-9156-468e-9563-7e7bff0ee25b","http://resolver.tudelft.nl/uuid:767e71bd-9156-468e-9563-7e7bff0ee25b","Knowledge based method for solving complexity in design problems","Vermeulen, B.","Van Tooren, M.J.L. (promotor); Benedictus, R. (promotor)","2007","The process of design aircraft systems is becoming more and more complex, due to an increasing amount of requirements. Moreover, the knowledge on how to solve these complex design problems becomes less readily available, because of a decrease in availability of intellectual resources and reduced knowledge transfer opportunities. Aerospace companies need to capitalise on the knowledge available within their companies, in order to deal with the challenges of increasing complexity and competition. The research presented in this thesis contributes to tackling the above challenges. A knowledge based method for solving complex detailed design problems is presented. The process of setting-up a solution finding approach is discussed by means of a design problem in the detailed design of fibre metal laminate (FML) fuselage panels. The principles of knowledge based engineering (KBE) are used to setup a software application for finding solutions to the detailed design problem in FML. A method for solving complexity in design problems is presented. The method uses a structured approach of transforming the real world problem, via an expert view on the problem, to a mathematical model of the problem. Finally a solution finding strategy is tailored for the problem at hand, by combining available solution finding knowledge with expert problem solving knowledge from different knowledge domains.","fibre metal laminates; knowledge based engineering; constraint programming; heuristics; engineering ontologies","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:d67f6fe7-59c5-4357-903e-e3c3891e2721","http://resolver.tudelft.nl/uuid:d67f6fe7-59c5-4357-903e-e3c3891e2721","Reconstructing design, explaining artifacts: Philosophical reflections on the design and explanation of technical artifacts","De Ridder, G.J.","Kroes, P.A. (promotor); Meijers, A.W.M. (promotor)","2007","Philosophers of science have by and large neglected technology. In this book, I have tried to do something about this lacuna by analyzing a few aspects of technical artifacts from a philosophical angle. The project was part of the research program ""The Dual Nature of Technical Artifacts"" based at Delft University of Technology in the Netherlands. Technical artifacts are both plain physical objects and objects that have been purposefully made for a purpose; which is to say they have a physical structure and a technical function. As a result, they belong equally in a purely physical conceptualisation of the world ""in which human intentions and goals seem to have no place"" and in an intentional conceptualisation, which is used to describe and understand people and their mental lives. My main goal was to find out how these two philosophically very different aspects of artifacts are related to one another. To achieve this goal, I looked at two contexts in which these aspects are regularly brought together in a systematic fashion. First, the context of design; design can be characterized as a transition from a desired function or goal to a physical structure. In particular, I have studied and analyzed the role of functional decomposition in design processes. The second context is the explanation of how artifacts are able to fulfill their technical function in virtue of their specific physical structure. The result of this part of the project is a general account of such explanations.","philosophy of technology; philosophy of science; engineering design; functional decomposition; function; explanation; technical artifacts","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:577a88b0-9b5a-49f4-94ec-0e7dbb00c1ab","http://resolver.tudelft.nl/uuid:577a88b0-9b5a-49f4-94ec-0e7dbb00c1ab","Impact of Principles on Enterprise Engineering","Op 't Land, M.; Proper, H.A.","","2007","Increasingly, organizations make use of enterprise architectures to direct the development of the enterprise as a whole and the development of their IT portfolio in particular. This steering and directing is done by means of principles, which are essentially regarded as constraints on the design space for enterprise engineers, thus guiding them in their design efforts. In this paper we study the potential constraining effect of principles on the design of enterprises as well as the guidance designers may receive from these principles. We start by providing a brief discussion on the concepts of enterprise architecture and enterprise engineering. We continue by discussing a strategy to make principles specific and measurable enough to indeed allow them to constrain design space. This is followed by a discussion of a number of examples, taken from real-life practice, illustrating the steering effect of principles. Finally, we also briefly pay attention to the process that may be followed in formulating and formalizing principles.","principles; enterprise architecture; enterprise engineering; implementation","en","conference paper","University of St. Gallen : St. Gallen, Switzerland","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:8044a1e4-5f34-4b60-b328-3a3c3dee78fb","http://resolver.tudelft.nl/uuid:8044a1e4-5f34-4b60-b328-3a3c3dee78fb","Evolutionaire productontwikkeling: Productfasen beschrijven de meest waarschijnlijke levensloop van een product; Evolutionary Product Development: how ""product phases"" can map the status quo and future of a product","Eger, A.O.","Buijs, J.A. (promotor); Drukker, J.W. (promotor)","2007","In the field of industrial design engineering, research was until now concentrated on ergonomics, marketing, design methodology, etcetera. However, very little research has been undertaken studying the relationships between form giving and the following aspects: functionality, ergonomics, production and marketing. In this thesis, the phenomena that appear during the various phases of a product's life have been summarized. These phenomena apply amongst others to the market (is the product new to the market or are there a lot of competitors?), the functionality (is it possible to improve the functionality or has it reached a high degree of perfection?), and the ergonomics (has enough attention been paid to the product's ease of use, or is there scope for improvement?). The regularities that were found have been analysed and described. This has led to six product phases: performance, optimisation, itemisation, segmentation, individualisation, and awareness. The six phases are placed in a chronological order such that predictions about new or future products can be made. This can be done by positioning a product, based on its product characteristics, into one of the product phases. When developing a future product, a designer can add to the product characteristics of the next product phase, thus creating added value for the intended user. In this way, the product phases can help a designer in creating the next generation of a product.","product development; industrial design engineering; product phase; future products; functionality; styling","nl","doctoral thesis","Lemma","","","","","","","","Industrial Design Engineering","","","","",""
"uuid:e3738f36-eb18-4e02-bfeb-437c476be97c","http://resolver.tudelft.nl/uuid:e3738f36-eb18-4e02-bfeb-437c476be97c","Development and application of 13C-labeling techniques: Analyzing the pentose phosphate pathway of Penicillium chrysogenum","Kleijn, R.J.","Heijnen, J.J. (promotor)","2007","The 13C-labeling technique is a powerful characterization tool within the field of metabolic engineering aimed at determining intracellular steady state fluxes. The provided metabolic snapshots enable researchers to better understand and predict the phenotypic behavior of a micro-organism as a result of genetic alterations and/or different environmental conditions. In general, two main methods can be distinguished for deriving metabolic flux patterns from measured 13C-label distributions; (i) the local flux analysis approach, which determines the intracellular fluxes around a selected metabolite node and (ii) the whole isotopomer modeling approach which aims at estimating all fluxes throughout a predefined reaction network model. In this thesis the different 13C-labelling techniques were further developed and the available analytical platforms were applied for the analysis of the metabolic fluxes in the well-characterized yeast Saccharomyces cerevisiae and the less-studied filamentous fungi Penicillium chrysogenum. Throughout this thesis special attention was paid to the flux through the oxidative branch of the pentose phosphate pathway (PPP), which is of prime importance for penicillin synthesis in P. chrysogenum.","metabolism; flux analysis; penicillium chrysogenym; penicillin; metabolic engineering","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:8449ea9e-7311-4c2b-9ae9-d51d949bd904","http://resolver.tudelft.nl/uuid:8449ea9e-7311-4c2b-9ae9-d51d949bd904","Efficient implementation of serial multi-agent model predictive control by parallelization","Negenborn, R.R.; De Schutter, B.; Hellendoorn, J.","","2007","We discuss an extension of a scheme recently proposed for multi-agent control of large-scale networks, like power networks, road traffic networks, water networks, etc. The original scheme uses serial sequences of agent interactions that under some assumptions make agents locally choose actions that are globally optimal. However, some weaknesses of the approach appear when applied to large-scale networks. We identify these weaknesses and propose, for problems with a tree-structured problem topology, an improvement based on parallelization of the serial scheme. With an example we illustrate and compare the schemes.","control engineering computing; multi-agent systems; predictive control; trees (mathematics)","en","conference paper","IEEE","","","","","","","","Mechanical, Maritime and Materials Engineering","Delft Center for Systems and Control","","","",""
"uuid:ceeb5582-4e0d-4102-a2e3-846f7312e16a","http://resolver.tudelft.nl/uuid:ceeb5582-4e0d-4102-a2e3-846f7312e16a","Grammar Engineering Support for Precedence Rule Recovery and Compatibility Checking","Bouwers, E.; Bravenboer, M.; Visser, E.","","2007","A wide range of parser generators are used to generate parsers for programming languages. The grammar formalisms that come with parser generators provide different approaches for defining operator precedence. Some generators (e.g. YACC) support precedence declarations, others require the grammar to be unambiguous, thus encoding the precedence rules. Even if the grammar formalism provides precedence rules, a particular grammar might not use it. The result is grammar variants implementing the same language. For the C language, the GNU Compiler uses YACC with precedence rules, the C-Transformers uses SDF without priorities, while the SDF library does use priorities. For PHP, Zend uses YACC with precedence rules, whereas PHP-front uses SDF with priority and associativity declarations. The variance between grammars raises the question if the precedence rules of one grammar are compatible with those of another. This is usually not obvious, since some languages have complex precedence rules. Also, for some parser generators the semantics of precedence rules is defined operationally, which makes it hard to reason about their effect on the defined language. We present a method and tool for comparing the precedence rules of different grammars and parser generators. Although it is undecidable whether two grammars define the same language, this tool provides support for comparing and recovering precedence rules, which is especially useful for reliable migration of a grammar from one grammar formalism to another. We evaluate our method by the application to non-trivial mainstream programming languages, such as PHP and C. Presented at LDTA 2007 Seventh Workshop on Language Descriptions, Tools and Applications, 25-3-2007, Braga, Portugal","precedence; precedence rules; disambiguation; priorities, associativity; grammar engineering; grammar recovery; parsing; YACC; SDF","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:a6bb4dac-ea93-4cae-b688-94e68d684314","http://resolver.tudelft.nl/uuid:a6bb4dac-ea93-4cae-b688-94e68d684314","A preliminary formal specification of virtual organization creation with RAISE specification language","Nami, M.R.; Sharifi, M.; Malekpour, A.","","2007","Recently, several flavors of Formal Methods (FMs) have been gaining industrial acceptance and production quality software tools have begun emerging. Domain Engineering (DE) has been introduced as one of outstanding ideas in software development. It serves form al methods that provide a rigorous, mathematical based framework (domain model) for specifying, defining, and verifying systems in the software development. The increasing demands for extended products and services along with advances in IT industry have motivated researchers to create Virtual Organizations (VOs) in order to better respond to business opportunities and produce qualitative services and products. The purpose of this paper is to describe Virtual Organization and Domain engineering with introducing formal methods especially RAISE as a formal method that has been used successfully on diverse applications. Then, a primary formal model is presented using RAISE method and its language (RSL) formula for the improvement of VO creation process. Formal model presented in this paper is provable to implement. It improves reusability and reliability in such environments.","software engineering; formal methods; RAISE method; collaborative networks; virtual organization","en","conference paper","IEEE Computer Society","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:948a633f-d6c5-42f2-ad06-c9436f10d30d","http://resolver.tudelft.nl/uuid:948a633f-d6c5-42f2-ad06-c9436f10d30d","Issues in the design of facilitated collaboration processes","Kolfschoten, G.L.; Den Hengst-Bruggeling, M.; De Vreede, G.J.","","2007","","facilitation - facilitation techniques -collaboration process design; Collaboration Engineering; design and preparation; Group Support Systems","en","journal article","Springer","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:9a5b8bc2-a2b4-478c-87d7-b97905c67daf","http://resolver.tudelft.nl/uuid:9a5b8bc2-a2b4-478c-87d7-b97905c67daf","Distance laboratories in electrical engineering","Bauer, P.; Fedák, V.","","2007","","e-learning; remote controlled experiments; engineering education","en","conference paper","Tulip","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:8e1a7202-8eee-4b45-81ac-174b66d0a7c7","http://resolver.tudelft.nl/uuid:8e1a7202-8eee-4b45-81ac-174b66d0a7c7","The ethical cycle","Van De Poel, I.; Royakkers, L.","","2007","","ethics; engineering; moral problems; designing; deliberation","en","journal article","Springer","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:33f774de-f2ec-4254-889d-8c7430c52d4f","http://resolver.tudelft.nl/uuid:33f774de-f2ec-4254-889d-8c7430c52d4f","Adopting and Evaluating Service Oriented Architecture in Industry","Nasr, K.A.; Gross, H.; Van Deursen, A.","","2006","In this paper, we present a descriptive case study covering the re-engineering and furhter evolution of adopting service oriented architecture (SOA) in industry. The goal of this case study is to identify the possible benefits and bottlenecks of adopting SOA, as well as to come up with best practices and research directions based on real-life experience gained in IT industry. The case involves an application portfolio of over 700 systems for a company in the transport sector. First, the case study involves the engineering of a portal application involving the integration of various services via the Enterprise Service Bus (ESB). Second, the case study is concerned with the setting up of a central coordination point within the organization to deal with SOA-related integration requests and requirements coming from different business units. Finally, the case discusses the actual implementation and integration of a service through the ESB. From this case study, a list of lessons learned and research directions is obtained. Preprint accepted for publication in the Proceedings of the European Conference on Software Maintenance and Reengineering (CSMR), 2010, madrid (Spain), 15-18 March, 2010, IEEE Computer Society","SOA; re-engineering; case study","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:e33139ca-e181-4c62-87dc-23e55010eac8","http://resolver.tudelft.nl/uuid:e33139ca-e181-4c62-87dc-23e55010eac8","Fatigue life prediction and strength degradation of wind turbine rotor blade composites","Nijssen, R.P.L.","Beukers, A. (promotor)","2006","Wind turbine rotor blades are subjected to a large number of highly variable loads, but life predictions are typically based on constant amplitude fatigue behaviour. Therefore, it is important to determine how service life under variable amplitude fatigue can be estimated from constant amplitude fatigue behaviour. A life prediction contains different, partly independent, elements: · the counting method, used for describing variable amplitude signals as a collection of constant amplitude cycles · formulations for describing S-N curves which relate the stresses to the number of cycles to failure · constant life diagrams which are made up of S-N curves for different stress ratios · damage rules, which relate the life expectancy of a specimen to the stress history For the description of damage, two models were investigated and compared, viz. the Miner's sum method and strength-based life prediction. In the Miner's sum method, the results of a counting method and constant amplitude fatigue behaviour description are converted into a damage parameter, ""Miner's sum"". Potential effects of load order are not taken into account. Moreover, the value of the damage parameter only indicates whether or not failure occurred: it does not relate to a physically quantifiable damage. These are limitations to the model which suspectedly might cause inaccurate predictions. In the strength-based method, life is predicted by calculating the effect of each load cycle on strength, until the load exceeds the remaining strength. An expected advantage of this cycle-by-cycle method is, that sequence effects can be implicitly included. Moreover, the damage parameter is at all times related to a physically quantifiable parameter (viz. strength). The successful application of the strength-based method requires a description of the post-fatigue strength, which entails considerable experimental effort. In addition, a strength-based life prediction is much more computationally intensive than Miner's sum and can not always utilise the same counting methods. In the comparison of the Miner's sum and the strength-based method, the influence and significance of the other life prediction elements, such as counting methods and description of constant amplitude fatigue behaviour on life prediction are included. The experimental research involved a considerable amount of material tests. The material tests give a detailed image of static strength, constant and variable amplitude fatigue behaviour (both block tests and (variants of) the WISPER spectrum were used), as well as strength degradation for different glass-fibre reinforced laminates. By selecting a single coupon geometry for all material tests on a single material, and the definition and use of standard test conditions, a consistent database was created. The block-test experiments confirm the existence of sequence effects on life, although more data are required to fully quantify them. The residual strength tests show the strength degradation after fatigue for a range of fatigue load conditions. Significant tensile strength degradation is observed in R=0.1 and R=-1 fatigue experiments. Generally, compressive strength remains within the boundaries of the initial static strength distribution. This behaviour was observed for different laminates. The significance of an adequate description of the constant amplitude behaviour is evident from the various life predictions. Commonly used simplifications, such as the Linear Goodman Diagram, result in highly non-conservative predictions. The residual strength model yields more conservative predictions than Miner's sum for the investigated tension-dominated load sequences. The experimental effort required for the determination of the strength degradation, and the computational effort do not justify this relatively small advantage. For future research, it is recommended to further improve the description of the constant life diagram. This work is focussed on fatigue of composites for wind turbine rotor blades. Nevertheless, the results are relevant for other composite structures as well.","wind engineering; laminate; composites; fatigue; strength; life; prediction; wind energy","en","doctoral thesis","Knowledge Centre WMC and DPCS group of Aerospace Engineering","","","","","","","","Aerospace Engineering","","","","",""
"uuid:e80d55d3-bece-4665-b932-374960ce960c","http://resolver.tudelft.nl/uuid:e80d55d3-bece-4665-b932-374960ce960c","Progressive visualization of incomplete sonar-data sets: From sea-bottom interpolation and segmentation to geometry extraction","Loke, R.E.","Jansen, F.W. (promotor); du Buf, J.M.H. (promotor)","2006","This thesis describes a visualization pipeline for sonar profiling data that show reflections of multiple sediments in the sea bottom and that cover huge survey areas with many gaps. Visualizing such data is not trivial, because they may be noisy and because data sets may be very large. The developed techniques are: (1) Quadtree interpolation for estimating new sediment reflections, at all gaps in the longitude-latitude plane. The quadtree is used for guiding the 3D interpolation process: gaps become small at low spatial resolutions, where they can be filled by interpolating between available reflections. In the interpolation, the reflection data are cross correlated in order to construct continuity of multiple, sloping reflections. (2) Segmentation and boundary refinement in an octree in order to detect sediments in the sonar data. In the refinement, coarse boundaries are reclassified by filtering the data with a planar kernel that is positioned on the boundary between the sediments. This improves existing algorithms and implies that gaps can also be interpolated during the down projection in the octree. (3) Triangulation conform a new version of the Discretized Marching Cubes algorithm that improves the sharpness of the extracted surfaces that lay between the sediments. By combining different surface modeling variants on the high-resolution subgrid of a cuberille, sharp manifold surfaces can be generated, in order to preserve concave and convex sediment shapes. (4) Integration of the techniques in a single-octree framework in order to make it scalable and applicable for the visualization of large data sets. The visualization pipeline has been applied for interactive visualization at low and high spatial resolutions.","computer graphics; pattern recognition; image processing; oceanic engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:bc099609-47bd-4ad8-91ad-2a4a9a949c0f","http://resolver.tudelft.nl/uuid:bc099609-47bd-4ad8-91ad-2a4a9a949c0f","Seismic interferometry-turning noise into signal","Curtis, A.; Gerstoft, P.; Sato, H.; Snieder, R.; Wapenaar, C.P.A.","","2006","Turning noise into useful data—every geophysicist's dream? And now it seems possible. The field of seismic interferometry has at its foundation a shift in the way we think about the parts of the signal that are currently filtered out of most analyses—complicated seismic codas (the multiply scattered parts of seismic waveforms) and background noise (whatever is recorded when no identifiable active source is emitting, and which is superimposed on all recorded data). Those parts of seismograms consist of waves that reflect and refract around exactly the same subsurface heterogeneities as waves excited by active sources. The key to the rapid emergence of this field of research is our new understanding of how to unravel that subsurface information from these relatively complex-looking waveforms. And the answer turned out to be rather simple. This article explains the operation of seismic interferometry and provides a few examples of its application.","geophysical techniques; seismology; structural engineering; earthquakes; interferometry","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:5225c907-a05e-42ce-874c-fb00678600eb","http://resolver.tudelft.nl/uuid:5225c907-a05e-42ce-874c-fb00678600eb","Die Entwicklung von Abwasserentsorgungskonzepten unter dem Einfluss von Urbanisierung und Industrialisierung im 19. Jahrhundert - dargelegt an ausgewählten Beispielen -","Koch, Angela","Bollerey, F. (promotor); Mácel, O. (promotor)","2006","Abstract not available","hydraulic engineering; European metropolises; Emscher-system; public health; river pollution","de","doctoral thesis","","","","","","","","","Architecture","","","","",""
"uuid:3b0b2f19-1776-4980-94b8-f53891c2d034","http://resolver.tudelft.nl/uuid:3b0b2f19-1776-4980-94b8-f53891c2d034","Optimization of piston for diesel engine using Kriging model","Jeong, S.; Minemura, Y.; Obayashi, S.","","2006","Diesel engine combustion chamber which reduces exhaust emission has been designed using CFD analysis and optimization techniques. In order to save computational time for design, the Kriging model, one of the response surface models, is adopted here. For the robust exploration, both the estimated function value of the model and its uncertainty are considered at the same time. In the present problem, the k-means method is used to limit a number of additional sample points to a reasonable level. Among the additional sample points, two combustion chamber shapes dominate the baseline configuration in terms of all objective functions. Compared with the previous optimization with the evolutionary algorithm, its computational time for design was cut by 95%. The results indicate that the present method is a practical approach for real-world applications.","diesel engine; exhaust emission reduction; Kriging model","en","conference paper","","","","","","","","","","","","","",""
"uuid:dcc1dac5-6db5-4600-a5d1-2b13f4506e41","http://resolver.tudelft.nl/uuid:dcc1dac5-6db5-4600-a5d1-2b13f4506e41","Use of POD in control of flow through porous media","Van Doren, J.; Markovinovic, R.; Jansen, J.D.","","2006","During the design of development concepts for the exploitation of oil and gas reservoirs, frequent use is made of numerical simulation of the flow of multi-phase fluids through porous rock. Recently, increased attention has been paid to systematic optimization of well positions and operating parameters (rates, pressures) over the life of the reservoir. Here we consider optimization of the displacement of oil towards production wells through the injection of water in other wells. Model-based optimal control of this “water flooding” process generally involves multiple simulations, which makes it into a time-consuming process. A potential way to address this issue is through the use of proper orthogonal decomposition (POD), We addressed the scope to speed up optimization of water-flooding a heterogeneous reservoir with multiple injectors and producers. We used an adjoint-based optimal control methodology that requires multiple passes of forward simulation of the reservoir model and backward simulation of an adjoint system of equations. We developed a nested approach in which POD was first used to reduce the state space dimensions of both the forward model and the adjoint system. After obtaining an optimized injection and production strategy using the reduced-order system, we verified the results using the original, high-order model. If necessary, we repeated the optimization cycle using new reduced-order systems based on snapshots from the verification run We tested the methodology on a reservoir model with 882 states (441 pressures, 441 saturations) and an adjoint model of 882 states (Lagrange multipliers). We obtained reduced-order models with 35-43 states only. The reduction in computing time was 52%.","proper orthogonal decomposition; model reduction; optimal control; reservoir engineering; porous media; water flooding","en","conference paper","Delft University of Technology; European Community on Computational Methods in Applied Sciences (ECCOMAS)","","","","","","","","Mechanical, Maritime and Materials Engineering","","","","",""
"uuid:744eaa02-8157-4c90-ad1c-f4dacd144056","http://resolver.tudelft.nl/uuid:744eaa02-8157-4c90-ad1c-f4dacd144056","Use of POD in control of flow through porous media","Van Doren, J.; Markovinovic, R.; Jansen, J.D.","","2006","During the design of development concepts for the exploitation of oil and gas reservoirs, frequent use is made of numerical simulation of the flow of multi-phase fluids through porous rock. Recently, increased attention has been paid to systematic optimization of well positions and operating parameters (rates, pressures) over the life of the reservoir. Here we consider optimization of the displacement of oil towards production wells through the injection of water in other wells. Model-based optimal control of this water flooding process generally involves multiple simulations, which makes it into a time-consuming process. A potential way to address this issue is through the use of proper orthogonal decomposition (POD), We addressed the scope to speed up optimization of water-flooding a heterogeneous reservoir with multiple injectors and producers. We used an adjoint-based optimal control methodology that requires multiple passes of forward simulation of the reservoir model and backward simulation of an adjoint system of equations. We developed a nested approach in which POD was first used to reduce the state space dimensions of both the forward model and the adjoint system. After obtaining an optimized injection and production strategy using the reduced-order system, we verified the results using the original, high-order model. If necessary, we repeated the optimization cycle using new reduced-order systems based on snapshots from the verification run We tested the methodology on a reservoir model with 882 states (441 pressures, 441 saturations) and an adjoint model of 882 states (Lagrange multipliers). We obtained reduced-order models with 35-43 states only. The reduction in computing time was 52%.","proper orthogonal decomposition; model reduction; optimal control; reservoir engineering; porous media; water flooding","en","conference paper","","","","","","","","","","","","","",""
"uuid:a13689ac-ab8c-4952-ab23-86f3c55963fa","http://resolver.tudelft.nl/uuid:a13689ac-ab8c-4952-ab23-86f3c55963fa","CFD analysis of flow in the solid propellant start system of a liquid propellant engine","Kamiri, H.; Taheri, E.E.","","2006","Starters are mechanisms that are used for generating the working fluid for initial rotation of LPE (Liquid Propellant Engines) turbopumps. The function of the start system is preparation of initial power for starting a turbine. This turbine is attached to the fuel and oxidizer pumps. When these pumps work in a suitable case, the required power of turbine, is prepared from another source (gas generator) and then there is not need to starter operation. A solid propellant starter is a solid propellant motor that instead of thrust, momentum of its exit gases is used for rotating the turbine. The values of power and operating time of starter, are specified from downstream conditions of the start system. Generally, the type and efficiency of turbine and pumps, propellant rate and density, control mechanisms in the path of propellant and etc , are determinant of these values. In this type of start system, gases due to combustion, pass through a convergent-divergent nozzle and enter the turbine and rotate it. In this paper, with due consideration to the role and importance of start system in the process of LPE operation, in order to better recognition of present phenomena in this system, the flow due to combustion in a start system that uses solid propellant, has been simulated via solving the navier-stokes equations. These equations have been expressed in the form of time-dependent, axisymmetric, compressible and viscous and have been solved by means of finite volume methods in company with continuity and energy equations. For finite volume methods the domain is divided up into a number of control volumes, with the value at the centre of the control volume being held to be representative for the value over the entire control volume. By integrating the PDEs over the control volume the equations are cast into a form that ensure conservation.","Liquid Propellant Engine; solid propellant; start system; CFD Analysis","en","conference paper","","","","","","","","","","","","","",""
"uuid:8b3c60a5-4e17-4680-b7c6-252fb4ae87ca","http://resolver.tudelft.nl/uuid:8b3c60a5-4e17-4680-b7c6-252fb4ae87ca","VIVACE: Multidisciplinary Decision Support","Homsi, P.","","2006","","collaboration; multidisciplinary; optimization; decision; knowledge; data management; virtual enterprise; aeronautic; aircraft; engine","en","conference paper","","","","","","","","","","","","","",""
"uuid:ce4bd9ee-4eb4-4569-83a2-6bf444b7d0dd","http://resolver.tudelft.nl/uuid:ce4bd9ee-4eb4-4569-83a2-6bf444b7d0dd","ILES and LES of Complex Engineering Turbulent Flows","Fureby, C.","","2006","The present study concerns the application of Large Eddy Simulation (LES) and Implicit LES (ILES) to engineering flow problems. Such applications are often very complicated, involving both complex geometries and complex physics, such as turbulence, chemical reactions, phase changes and compressibility. The aim of the study is to illustrate what problems occur when attempting to perform such engineering flow calculations using LES and ILES, and put these in relation to the issues originally motivating the calculations. The issues of subgrid modeling are discussed with particular emphasis on the complex physics that needs to be incorporated into the LES models. Results from representative calculations, involving incompressible flows around complex geometries, aerodynamic noise, compressible flows, combustion and cavitation, are presented, discussed and compared with experimental data whenever possible. In addition, we also compare predictions from LES and ILES with conventional Reynolds Averaged Navier-Stokes (RANS) models and Detatched Eddy Simulations (DES) for academically challenging flows, such as the flow around a cylinder and around a surface mounted 3D hill. It is found that both LES and ILES predict these flows more accurately than RANS and DES, and include more information about the dynamics of the flow.","LES; ILES; engineering applications; incompressible flow; compressible flow; flow noise; turbulent premixed combustion; cavitation","en","conference paper","","","","","","","","","","","","","",""
"uuid:cb6b18fb-f6e8-4c2d-a574-42df75899754","http://resolver.tudelft.nl/uuid:cb6b18fb-f6e8-4c2d-a574-42df75899754","Simulation of the internal ballistics of a liquid propellant engine start system in comparison with experimental verification","Karimi, H.; Taheri, E.E.","","2006","There are several methods for starting a complex mechanical system, for example a liquid propellant engine. One of common methods is the use of solid propellant gas generator that is named solid propellant starter. In this method, a solid propellant motor is used for gas generating and leading it towards power generation turbine. The turbine as an active element, rotates one or several pumps for providing propellants with suitable head and rate for consumers such as liquid propellant gas generator and combustion chamber. After moving of pumps and reaching to nominal conditions, the start system stops. Therefore in order to suitable and optimized designing of starter, the essential parameter is taking into account the downstream resistance of system. In a complex system such as a liquid propellant engine, the start system is one of the main and important components of engine and its operation affects directly on the other components of engine. Therefore the optimized designing of it, has special importance. On the one hand, the selection of solid propellant geometry (grain) that exist in this system, is one of main parameters and the most important function in the process of start system designing, because the geometry of solid propellant is determinant of burning area and consequently the burning pattern of solid propellant. Therefore it is an important factor in determining the performance of starting system. In this paper, the alterations of pressure and thrust of a starter with different solid propellant grains have been simulated and have been compared with experimental results. The very good agreement of theoretical and experimental results indicates that the accuracy of simulation process is excellent.","Liquid Propellant Engine; solid propellant starter; internal ballistics; simulation","en","conference paper","","","","","","","","","","","","","",""
"uuid:b5e99061-f673-4cd7-bac3-f47673f28627","http://resolver.tudelft.nl/uuid:b5e99061-f673-4cd7-bac3-f47673f28627","Nozzle effects on pulse detonation engines performance","Arian, M.; Tahsini, A.M.","","2006","Pulse detonation engine is a new concept across air-birthing propulsion systems. Today, due to the unsteady behavior of this type of engine, design optimizations are not completed yet. In this regard, recent studies are focused on the effects of nozzle implementation in this propulsion system. In this paper, the effect of nozzle shape (angle & length) on the impulse and frequency of engine cycle performance is studied. Results show that the nozzle increases the impulse which the direct nozzle has the largest effect. In the other words, the greater the divergence angle and the length of the nozzle, the smaller the impulse. On the other hand, results indicate that the presence of a nozzle would increase the cycle frequency; to be exact, the greater the divergence angle and the length of nozzle, the higher would be the frequency. However, since thrust is a function of both the impulse and the cycle frequency, a system optimization has to be performed in order to find out the optimized design conditions. Further, since combustion phenomenon is not considered in the quasi one dimensional code utilized in this work, results do caution some degrees of error. However, a comparison with experimental data validates the trend obtained in this paper.","pulse detonation engine; nozzle; impulse; thrust; frequency","en","conference paper","","","","","","","","","","","","","",""
"uuid:3193b766-e37b-4df3-91a1-a2bf9d5dc210","http://resolver.tudelft.nl/uuid:3193b766-e37b-4df3-91a1-a2bf9d5dc210","Design Exploration of Shielding Effect for Aircraft Engine Noise","Chiba, K.; Imamura, T.; Amemiya, K.; Jeong, S.; Yamamoto, K.","","2006","The multi-objective design exploration of the two-dimensional shielding effect for engine noise using V-tale wing has been performed. Two objective functions are considered as the minimization of the sound pressure level at the side and bottom locations relative to the fuselage, which values are evaluated by using the linearized Euler equation. Two design variables are defined as the wing length and the wing cant angle to set on the fuselage. The response surface method with kriging model is employed as the optimizer to reduce the time required for design exploration. As a result, there is no tradeoff between two objective functions, i.e., the sound pressure level at the side and bottom measuring locations can be reduced, simultaneously. The wing cant angle which is set at nearly 65 deg is most effective to shield the noise. It is justly the necessary condition to reduce the sound pressure level that the wing length becomes long. Moreover, a self-organizing map as a data mining technique obtains the knowledge in the design space regarding the correlation between the objective functions and the design variables.","computational aeroacoustics; aircraft engine noise; shielding effect; design exploration; data mining; self-organizing map","en","conference paper","","","","","","","","","","","","","",""
"uuid:dfded94b-f069-4afe-8b23-e2a1c1d1ad0d","http://resolver.tudelft.nl/uuid:dfded94b-f069-4afe-8b23-e2a1c1d1ad0d","Simulation of fluid-structure-interaction with free form membrane structures using an implicit coupling scheme with adaptive under relaxation","Wüchner, R.; Kupzok, A.; Bletzinger, K.U.","","2006","Due to their special load carrying behavior, membrane structures are using the material most efficiently. As a consequence, the realized structures are extremely light but susceptible to flow induced effects. The missing bending stiffness results in a complex coupling of stress state and membrane shape. This necessitates special form finding techniques to determine the mechanically defined shapes of equilibrium as prerequisite of the analysis of prestressed lightweight structures. Due to the almost negligible mass of the structure, the surface-coupled, partitioned fluid-structure-interaction computations with an explicit coupling scheme fail. To achieve numerically stable results, an implicit coupling strategy using interfield iterations with under relaxation is applied and for the sake of efficiency, the Aitken's acceleration technique is used. A software environment with integrated form finding capabilities is proposed focusing on aspects related to the coupling strategies. Two examples of membrane structures in an idealized wind flow demonstrate the success of the approach.","fluid-structure-interaction; membrane structures; form finding; partitioned approach; implicit coupling; adaptive under relaxation; wind engineering","en","conference paper","","","","","","","","","","","","","",""
"uuid:827b0532-2a73-4cd4-bf2a-be980b2a4835","http://resolver.tudelft.nl/uuid:827b0532-2a73-4cd4-bf2a-be980b2a4835","Engineering of redox metabolism in yeast: New strategies for improved glycerol production","Geertman, J.M.A.","Pronk, J.T. (promotor); Van Dijken, J.P. (promotor)","2006","Abstract not available","metabolic engineering; biotechnology","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:8473cf36-ea1a-4915-96b5-494f10e84b30","http://resolver.tudelft.nl/uuid:8473cf36-ea1a-4915-96b5-494f10e84b30","Numerical resolution of a shape optimization problem in hydraulic engineering","Alvarez-Vázquez, L.J.; Martínez, A.; Vázquez-Méndez, M.E.; Vilar, M.A.","","2006","In this work, we take interest in hydraulic structures that enable fish to over- come stream obstructions (such as dams and weirs) to their spawning and other river migrations. Particularly, we study the design of a vertical slot fishway, that is, a rect- angular channel built on a side of the dam, with a sloping floor, that is divided into a number of pools by baffles with slots. We look for the location and length of the baffles separating the pools, in order to obtain a suitable water velocity: it has to be great enough to attract fish to the channel, but it cannot be so great as to wash fish back downstream or to exhaust them to the point where they cannot continue their journey upriver. First we pose the problem as a shape optimization problem, where the state system is given by the shallow water (Saint-Venant) equations, the design variables are the location and length of the baffles, and the objective function is related to obtaining a suitable water velocity. Next, by using the domain derivative we give a detailed expression for the gradient of the objective function via the adjoint system. Following, we propose a characteristc-Galerkin method for solving the state system, and two algorithms to solve the optimization problem: a derivative-free algorithm, and a gradient-type method computing the cost gradient by solving the adjoint system with the characteristc-Galerkin method. Finally, we show numerical results obtained for a standard ten pools fishway.","optimal shape design; fishways; hydraulic engineering","en","conference paper","","","","","","","","","","","","","",""
"uuid:79840158-4619-4f7b-a4c1-49cdd2f122f1","http://resolver.tudelft.nl/uuid:79840158-4619-4f7b-a4c1-49cdd2f122f1","Investigation of the effect of two-components injectors arrangement on injecting rate in the combustion chamber of a liquid propellant engine","Saremi, M.; Taheri, E.E.; Dadkhah, M.; Ebrahimi, R.","","2006","In liquid propellant engines, the propellants (fuel and oxidizer) after passing the injectors, are injected to combustion chamber. Generally, in liquid propellant engines, two types of injectors - direct flow and centrifugal flow - are used. The direct flow injector, actuates as an orifice. The input flow to a centrifugal injector, gets the angular momentum and goes out conically. The angular momentum causes the powdering of output fluid. The injecting cones collide to each other and the mixing operation is accomplished. The mixing and powdering of droplets in the centrifugal injectors are accomplished better than the direct flow injectors. To this reason, in modern liquid propellant engines, the centrifugal injectors are used. The centrifugal injectors are divided to two types : one component and two components. At one component injectors, the fuel and oxidizer are injected separately, but at two components injectors, both oxidizer and fuel are injected from a complex structure. The injection rate at injector plate, is one of the effective parameters on walls cooling, combustion stability and propulsive force (thrust) in the combustion chamber. In order to attaining the suitable injection rate, the effect of injector arrangement must be investigated. In this paper, after designing five different plans, the optimum injection rate has been investigated and selected. The method is the meshing of injector plate, determining the input value of oxidizer and fuel rates into each element and then computation of injection rate by means of a computer code. The mentioned code computes the distribution of flow rate at the lateral section of combustion chamber by using the geometric conditions of injector plate, the position and the flow rate of injectors. This code is usable for all kinds of one and two components injectors and has been validated by using of experimental test possilbilities and the error has been lower than six percent.","liquid propellant engine; two-component injectors; injection rate (flux)","en","conference paper","","","","","","","","","","","","","",""
"uuid:6c9304a5-9472-4c9b-b8f9-ac966dad3586","http://resolver.tudelft.nl/uuid:6c9304a5-9472-4c9b-b8f9-ac966dad3586","Engineering of Saccharomyces cerevisiae for the production of fuel ethanol from xylose","Kuijper, S.M.","Pronk, J.T. (promotor); van Dijken, J.P. (promotor)","2006","For various reasons mankind is looking for alternatives for fossil fuels. One of these alternatives is ethanol made from plant biomass. However, the plant material when broken down by hydrolysis into its sugar monomers contains a significant amount of xylose, a 5-carbon-sugar or pentose. Contrary to the sugars with 6 carbon atoms (hexoses) wild type baker's yeast does not convert xylose into ethanol. The most widely used method for ethanol production is fermentation with Saccharomyces cerevisiae better known as baker's yeast. In order to obtain an economically viable process for fuel ethanol production, an organism is required that can also ferment the pentose fraction of the biomass hydrolysate to ethanol. Over the last three decades people have tried to introduce xylose metabolism in baker's yeast using two strategies. 1) The introduction of a bacterial xylose isomerase gene and 2) The introduction of the fungal genes coding for xylose reductase and xylitol dehydrogenase. Both strategies have been unsuccessful. The work in this thesis describes a major breakthrough in the anaerobic fermentation of xylose by bakers yeast. The breakthrough came with the discovery of the first fungal xylose isomerase, in the obligate anaerobic fungus Piromyces sp. E2. Contrary to the bacterial genes, this fungal xylose isomerase could be functionally expressed in Saccharomyces cerevisiae at high levels. The introduction of the isomerase into the genome enabled bakers yeast to grow aerobically on xylose as the sole carbon source. Eventually, using a strategy of combined metabolic and evolutionary engineering, a yeast strain was obtained with an anaerobic growth rate on xylose of 0.12 h-1 and a xylose consumption rate of 1.4 grams xylose per gram biomass per hour. The final conclusion that can be drawn from this work is that the kinetics of xylose fermentation are no longer a bottleneck in the industrial production of bioethanol with yeasts.","xylose isomerase; piromyces; fermentation; pentose; yeast; bioethanol; lignocellulose; metabolic engineering; evolutionary engineering; pentose phosphate pathway; hemicellulose","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:71850526-24f5-4b33-b93a-6319857f3308","http://resolver.tudelft.nl/uuid:71850526-24f5-4b33-b93a-6319857f3308","Engineering of aromatic amino acid metabolism in Saccharomyces cerevisiae","Vuralhan, Z.","Pronk, J.T. (promotor)","2006","Saccharomyces cerevisiae is a popular industrial microorganism. It has since long been used in bread, beer and wine making. More recently it is also being applied for heterologous protein production and as a target organism for metabolic engineering. The work presented in this thesis describes how S. cerevisiae may be used as a metabolic-engineering platform to produce aromatic compounds such as phenylalanine or its catabolites, phenylethanol and phenylacetate. In this thesis two research lines were followed: The first research line focused on the molecular identity and substrate specificity of 2-oxo-acid decarboxylase in S. cerevisiae whereas the second line of research investigated the elimination of feedback inhibition steps in the phenylalanine biosynthetic pathway in S. cerevisiae. The impact of feedback inhibition on the aromatic biosynthesis pathway was quantified by analyzing intra- and extracellular concentrations of relevant aromatic compounds in glucose-limited chemostat cultures of wild-type and engineered strains.","aromatic amino acid; yeast; engineering","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:0d7d5fd0-3d6c-48f0-8266-b04be9ed1010","http://resolver.tudelft.nl/uuid:0d7d5fd0-3d6c-48f0-8266-b04be9ed1010","A Conceptual Foundation of the ThinkLet Concept for Collaboration Engineering","Kolfschoten, G.L.; Briggs, R.O.; De Vreede, G.J.; Jacobs, P.H.M.; Appelman, J.H.","","2006","Organizations increasingly use collaborative teams in order to create value for their stakeholders. This trend has given rise to a new research field: Collaboration Engineering. The goal of Collaboration Engineering is to design and deploy processes for high-value recurring collaborative tasks, and to design these processes such that practitioners can execute them successfully without the intervention of professional facilitators. One of the key concepts in Collaboration Engineering is the thinkLet – a codified facilitation technique that creates a predictable pattern of collaboration. Because thinkLets produce a predictable pattern of interactions among people working together toward a goal they can be used as snap-together building blocks for team process designs. This paper presents an analysis of the thinkLet concept and proposes a conceptual object model of a thinkLet that may inform further developments in Collaboration Engineering.","collaboration engineering; thinkLets; collaboration; object oriented modeling; collaboration process design; facilitation; group support systems","en","journal article","Elsevier","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:6b77a054-6b1a-49fb-8551-d652418c4242","http://resolver.tudelft.nl/uuid:6b77a054-6b1a-49fb-8551-d652418c4242","Designing reactive distillation processes with improved efficiency","Almeida-Rivera, C.P.","Grievink, J. (promotor)","2005","In this dissertation a life-span inspired perspective is taken on the conceptual design of grassroots reactive distillation processes. Attention was paid to the economic performance of the process and to potential losses of valuable resources over the process life span. The research was cast in a set of goal-oriented engineering and specific scientific design questions. The scientific novelty of this work is based around four key aspects of reactive distillation process design: (i) the formulation of an extended design problem in reactive distillation achieved by refreshing it in the wider context of process development and engineering and in a more relevant way regarding sustainability; (ii) the definition of an integrated design methodology achieved by analyzing current design methodologies and bridging the gaps between them; while we suggest this methodology as a way to beat the design complexity by decomposition, it requires the mastery of many tools and many concepts; (iii) the improvement of design tools achieved by exploring and extending current techniques and systematically applying them to the reactive distillation case; (iv) the definition of performance criteria that can be used to account for the process performance from a life-span inspired perspective, as well as applications of them.","process systems engineering; reactive distillation; conceptual process design; multiechelon design approach; life-span inspired design methodology","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:de26132b-6f03-41b9-b882-c74b7e34a07d","http://resolver.tudelft.nl/uuid:de26132b-6f03-41b9-b882-c74b7e34a07d","Gellish: A generic extensible ontological language - design and application of a universal data structure -","Van Renssen, A.S.H.P.","Dietz, J.L.G. (promotor)","2005","Since long data storage and data communication lack a common standard universal data model as well as a common data language for the application domains of database users. This hampers data communication between systems and causes costly data conversion processes. Various solutions have been proposed. However, those solutions either have a limited scope and are mutually incompatible or are difficult to implement. This thesis presents an integral solution to this problem in the form of the semantically rich standard Open Source Gellish English language. Gellish enables electronic data storage and data exchange in a neutral and system independent way. Gellish is relatively easy to implement. Gellish English is the English variant of Gellish and is a structured subset of natural English. Variants for other languages are under development. Gellish enables automated translations between language variants. This means that Gellish English messages can be displayed in any other language variant. Gellish is an extension and integration of the concepts defined in various ISO and non-ISO standard data models and dictionary standards. The Gellish language can replace data models, and provides an extendable ontology with standard reference data for customization and harmonization of systems. A Gellish implementation typically uses the Gellish Table, which is a single table, based on an object-relation-object structure, that is sufficient to express any kind of factual information. The Gellish Dictionary / Taxonomy / Ontology can be used among others to harmonize the content of existing systems, such as data in Design systems, ERP systems and Procurement systems. It also enables the integration of data from different sources, such as data from various engineering and E-Business applications. For example, it enables to describe product catalogues in a system independent way or to describe product requirements, equipment designs, equipment performance, business processes and business transactions so that they can be exchanged between different systems from different parties without the need to convert or translate the data. Usage of Gellish is supported by an Open Source website on http://sourceforge.net/projects/gellish/.","ontology; data modeling; standardization; product modeling; language; engineering; dictionary; taxonomy; data exchange; data storage; application interface","en","doctoral thesis","Delft University Press","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:55097c53-45ba-4b10-848a-ccf622a1d724","http://resolver.tudelft.nl/uuid:55097c53-45ba-4b10-848a-ccf622a1d724","A Method for Component-Based and Service-Oriented Software Systems Engineering","Stojanovic, Z.","Sol, H.G. (promotor); Dahanayake, A.N.W. (promotor)","2005","Information technology (IT) and systems have become the backbone of modern enterprises providing a wealth of new opportunities for conducting business. The ability of an enterprise to manage the complexity of its information systems and rapidly adapt to business changes has been widely recognized as a crucial factor for business success. There is a growing consensus in the business/IT community that the way to create these complex and adaptive IT systems is to use components and services discrete units of business functionality that collaborate over contract-based interfaces using standard protocols and platforms. During the last few years, a variety of component-based development (CBD) and Web services (WS) technology and standards have been proposed for building complex enterprise-scale systems and providing effective inter-enterprise application integration. While the technology and implementation standards for CBD and WS have already been established in practice, further efforts are necessary to design methods and techniques for engineering these complex systems. The first proposed CBD methods inherited difficulties in recognizing the fundamental nature of components as design structures and treated components as software code packages. The CBD methods of a new generation have recently started to define components as the representation and implementation of autonomous business units. However, business components are often identified based on underlying business objects and, therefore, they are too fine-grained and data-oriented to be used effectively in the design and development of complex, Web-based and service-oriented applications.","component-based development; model-driven architecture; service-oriented software engineering","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:1f5f31e7-b83a-4b49-b622-bb461ae19d30","http://resolver.tudelft.nl/uuid:1f5f31e7-b83a-4b49-b622-bb461ae19d30","Deactivation of Hydroprocessing Catalysts: New insights in catalyst structure, activity and stability","Vogelaar, B.M.","Moulijn, J.A. (promotor)","2005","In dit proefschrift is de deactivering van hydroprocessing katalysatoren onderzocht. Katalysatoren zijn hulpstoffen die gebruikt worden om chemische reacties te bewerkstelligen, zonder daarbij zelf verbruikt te worden. Een bekend voorbeeld is de uitlaatkatalysator in de auto, die o.a. onverbrande brandstofresten omzet in kooldioxide en water. In de chemische industrie worden verschillende katalysatoren toegepast voor diverse processen. Deze katalysatoren zijn veelal aangebracht op een vaste drager (bijvoorbeeld korrels), en bevatten metalen als aktieve component. Hydroprocessing is zo’n katalytisch proces, gebruikt in de olieraffinage voor de produktie van schone benzine en diesel. Om de uitstoot van schadelijke stoffen te beperken moeten benzine en diesel aan steeds strengere eisen voldoen. Eén daarvan is het zwavelgehalte, dat de komende jaren moet worden verlaagd tot 0.005%. Aardolie bevat zwavelhoudende componenten en deze kunnen in de produkten (brandstoffen) terechtkomen. In de motor wordt zwavel omgezet in SOx, een belangrijke veroorzaker van zure regen. De meest effectieve manier om dit te voorkomen is het reduceren van de hoeveelheid zwavel in de brandstof. Dit doen de meeste olieraffinaderijen met behulp van hydrodesulfurization (HDS) ofwel hydroprocessing. Het proces maakt gebruik van waterstof (H2) om selectief de zwavelcomponenten om te zetten in “schone” koolwaterstoffen en zwavel-waterstofgas (H2S). Dit gebeurt met behulp van een hydroprocessing katalysator, bij hoge temperatuur en druk. De gevormde H2S wordt afgescheiden van de ontzwavelde brandstof, en omgezet in vaste zwavel voor diverse doeleinden. In tegenstelling tot wat de bovenstaande definitie doet vermoeden, hebben katalysatoren niet het eeuwige leven. Hun aktiviteit neemt langzaam af door deactivering, tot een punt wordt bereikt waarop de katalysator moet worden ververst. Dit geldt ook voor hydroprocessing katalysatoren, die gemiddeld 2 jaar meegaan. Het doel van dit onderzoek is het vaststellen van de belangrijkste oorzaken van deactivering. Bovendien willen we beter begrijpen hoe de katalysator werkt. Het beantwoorden van deze vragen kan helpen bij de ontwikkeling van katalysatoren met een betere werking en langere levensduur, nodig voor het halen van de toekomstige brandstofspecificaties. Conventionele hydroprocessing katalysatoren bevatten molybdeensulfide (MoS2) op een poreuze alumina drager (Al2O3). Meestal wordt nikkel (Ni) of cobalt (Co) toegevoegd als promoter, waardoor de aktiviteit van de katalysator sterk toeneemt. De resulterende aktieve component of aktieve fase wordt CoMoS of NiMoS genoemd. Deze fase heeft een gelaagde struktuur, bestaande uit steeds een laag molybdeen atomen tussen twee lagen zwavelatomen. Deze zwavelatomen schermen het aktieve metaal (molybdeen) af, waardoor geen reacties kunnen plaatsvinden. Echter, aan de randen van deze struktuur kunnen zwavelatomen ontbreken, waardoor op die plaatsen de reactie wél mogelijk is. De atomen van de promoter (Ni of Co) nemen vermoedelijk een plaats in aan deze randen. Omdat de reaktie alleen aan de buitenste randen kan plaatsvinden moeten de deeltjes van de aktieve fase zo klein mogelijk zijn. Er zijn verschillende mogelijke oorzaken voor de deactivering van hydroprocessing katalysatoren. Tijdens het proces zet zich een grafiet-achtige vaste substantie (“coke”) af op de katalysator. Dit kan leiden tot verstopping van de poriën van de drager, waardoor de aktieve fase onbereikbaar wordt voor de reaktanten. Ook kan de coke specifiek op de aktieve fase neerslaan, waardoor deze wordt afgeschermd. De deeltjes van de aktieve fase kunnen aglomereren (sinteren) tijdens het proces, waardoor het effectieve oppervlak van de randen kleiner wordt. Ook kunnen de promoter atomen (Ni of Co) losraken van de aktieve fase en zich nestelen op de drager (segregatie), waardoor de promoterende werking verloren gaat. De aktieve fase zou nog andere onbekende veranderingen kunnen ondergaan, waardoor de aktiviteit afneemt. Al deze mogelijkheden werden onderzocht. De depositie van kleine hoeveelheden coke op de katalysator had geen significante invloed op de deactivering. We concluderen daarom dat coke zich niet selectief afzet op de aktieve fase, maar eerder op de drager. Blijkbaar heeft de aktieve fase, zeker voor gepromoteerde katalysatoren, een “zelf-reinigende” werking. Deze zorgt ervoor dat coke niet kan worden gevormd op de aktieve fase, of direkt wordt afgebroken. Bij grotere hoeveelheden coke trad verstopping van poriën op; het porievolume van de katalysator nam significant af. Vreemd genoeg had dit nauwelijks invloed op de deactivering, waardoor dit een interessant onderwerp blijft voor toekomstig onderzoek. Wel concluderen we dat bij een te lage waterstoftoevoer en -druk, in het midden van de katalysatorkorrels een tekort aan waterstof ontstaat, waardoor zich daar relatief veel coke gaat ophopen. Dit is uiteraard ongunstig voor de werking van de katalysator. Sintering en segregatie traden niet op in onze experimenten. Daarbij moet worden opgemerkt dat katalysatoren in de industrie een complexere samenstelling hebben en langer worden gebruikt. In dat geval kunnen sintering en segregatie wél een rol spelen. De belangrijkste oorzaak van deactivering in ons onderzoek was een andere, strukturele verandering van de aktieve fase. De aktieve fase verliest zwavel tijdens de reactie, aldus onze conclusie. Dit fenomeen treedt met name op in gasfase reacties, waarschijnlijk omdat daar de verhouding waterstof / zwavel hoger ligt. Desalniettemin zou het verlies van zwavel mogelijk een rol kunnen spelen bij katalysatordeactivering in een industriële reactor. De ontzwavelingsreactie verloopt op twee manieren: Het zwavelatoom wordt direkt verwijderd uit het zwavelhoudende molecuul, of er vindt eerst een hydrogenering plaats, waarna het zwavelatoom wordt verwijderd. Tot nu toe werd veelal aangenomen dat voor beide reacties een bereikbaar metaalatoom beschikbaar moet zijn aan de rand van de aktieve fase. Dat wil zeggen, er moeten één of meerdere zwavelatomen ontbreken aan de rand, wat een zogenaamde vacante positie oplevert. Uit onze resultaten concluderen we dat de (direkte) verwijdering van zwavel uit het molecuul inderdaad plaatsvindt op een vacante positie. De hydrogeneringsstap vindt volgens onze conclusies niet plaats op deze posities, maar juist op zwavelatomen aan de rand van de aktieve fase. Op basis hiervan stellen we een gedetailleerd model voor van de struktuur van de aktieve fase, alsmede een model voor het reactiemechanisme.","Chemical engineering; Catalysis; Hydroprocessing; Deactivation","en","doctoral thesis","Ponsen & Looijen B.V., Wageningen","","","","","","","2010-05-08","Applied Sciences","DelftChemTech","","","",""
"uuid:2e2f45fa-d33c-45d5-befc-b755dfc69d3d","http://resolver.tudelft.nl/uuid:2e2f45fa-d33c-45d5-befc-b755dfc69d3d","Capacity building in coastal engineering with a focus to countries in transition","Verhagen, H.J.","","2005","Coastal engineering is a complex art. At this moment a limited number of phenomena can understood with the help of the laws of physics and fluid mechanics. For the remainder, formulas have been developed with limited accuracy. In addition, input data are also limited available, and form another source of uncertainty. Consequently, a sound engineering approach is required, based on practical experience and supported by physical and mathematical models. Standard solutions do not exist in coastal engineering; solutions depend very much on local circumstances as well as the social and political approach towards the coast. Consequently the transfer of coastal engineering knowledge is a complex art as well. Because of the different circumstances, training of engineers from countries in transition therefore has to be different from training of engineers from a country with a strong coastal engineering tradition.","education; training; coastal engineering; capacity building","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:6dbf0e52-bf8a-4911-bf4b-1e7f361e037e","http://resolver.tudelft.nl/uuid:6dbf0e52-bf8a-4911-bf4b-1e7f361e037e","The Molen Polymorphic Media Processor","Kuzmanov, G.K.","Vassiliades, S. (promotor)","2004","In this dissertation, we address high performance media processing based on a tightly coupled co-processor architectural paradigm. More specifically, we introduce a reconfigurable media augmentation of a general purpose processor and implement it into a fully operational processor prototype. The proposed media Molen prototype is implemented on the Xilinx Virtex II Pro technology. Its entire backbone infrastructure utilizes less than 1% of the reconfigurable resources of the prototyping chip xc2vp20. Consequently, virtually the entire reconfigurable area is available for implementations of media processing units and memory. Such a reconfigurable area is used to addresses computational intensive kernel and memory ntensive access requirements of media applications. More pecifically, we consider for reconfigurable implementation several MPEG-4 performance limiting kernels including the repetitive padding, the accepted quality function, and the discrete wavelet transform. Compared to pure software execution, we obtain up to two orders of magnitude kernel speedups. The memory bandwidth limitation problem is solved by introducing a scalable, rectangularly addressable memory organization for accessing block-organized visual data. When implemented in hardware, the proposed memory organization suggests 8X data transfer speedups. We evaluate the proposed processor prototype also at the application level by experimenting on MJPEG, MPEG-2, and MPEG-4. The experiments clearly indicate that our proposal can be employed to accelerate media applications. More specifically, the performance results obtained at the application level suggest that overall application speedups of 2X-3X can be expected, approaching up to 98% of the theoretically attainable maximum application speedups. Reconfigurable technologies, other than Virtex II Pro , are also considered and suggest similar performance improvements giving clear indications that our proposal is general and technology independent.","reconfigurable computing; polymorphic processors; media processors; computerarithmetic; computer design and engineering; multimedia enhancements; hardware accelerators","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:e5ff09af-7704-4a46-b955-7509b6e89b4a","http://resolver.tudelft.nl/uuid:e5ff09af-7704-4a46-b955-7509b6e89b4a","Process system innovation by design: Towards a sustainable petrochemical industry","Dijkema, G.P.J.","Weijnen, M.P.C. (promotor); Grievink, J. (promotor)","2004","","fuel cells; functional modelling; innovation; olefins; petrochemical industry; process systems engineering; sustainable development","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:a6a63694-d0c6-4102-a06e-11b9ea563a8d","http://resolver.tudelft.nl/uuid:a6a63694-d0c6-4102-a06e-11b9ea563a8d","CAFCR: A Multi-view Method for Embedded Systems Architecting. Balancing Genericity and Specificity","Muller, G.J.","Vree, W.G. (promotor)","2004","This thesis describes the CAFCR method for embedded systems architecting. Embedded systems are software and technology intensive systems. Typical examples of software and technology intensive products are televisions, DVD-players, MRI scanners, and printers. The creation of these products is a multi-disciplinary effort by hundreds of engineers. The method is based on multiple views that are integrated by qualities and architectural reasoning. Story telling is used as complementary submethod to gather requirements and to make specification and design discussions specific. The architecting method is applied in retrospect on the development of a Medical ImagingWorkstation. The Medical ImagingWorkstation case is used to evaluate the method. The thesis is structured in four parts: Introduction, Architecting method, Medical Imaging Workstation case, and Evaluation and Conclusions. The first part articulates the research question and the hypothesis. The last part assesses the hypothesis by evaluating the use of the method in the case.","systems architecting; systems engineering; design","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:6dcd9b4a-bf75-4b8c-8c40-435fe861988b","http://resolver.tudelft.nl/uuid:6dcd9b4a-bf75-4b8c-8c40-435fe861988b","Ecological Engineering and Civil Engineering works","Van Bohemen, H.D.","Hendriks, Ch.F. (promotor)","2004","This thesis provides a survey of the research results of the relationship between on the one hand the construction, management and maintenance of civil engineering works, and on the other hand the environment, nature and landscape, with the main focus on motorways and coastal protection. The growing number and increase in size of civil engineering works and the growing need for protection measures of the sandy coasts have led to an ever increasing risk of adverse effects on the nature and landscape of the Netherlands, as well as to an increase in the degree of the impact of these effects. Consequently, such institutions as the Road and Hydraulic Engineering Institute (Dienst Weg- en Waterbouwkunde - DWW -) of the Directorate General of Public Works and Water Management (Rijkswaterstaat) of the Ministry of Transport, Public Works and Water Management have carried out extensive studies of possible adverse effects. Based on these studies were carried out of measures intended to prevent adverse effects, to avoid their impact and to mitigate and/or to compensate for them (i.e. to take measures elsewhere in order to bring about a no net loss of nature values), apart from measures that can produce positive effects. From a scientific point of view as well as of the interest of society it is important to pay attention to the possibilities for better inserting civil engineering work (e.g. construction and use of infrastructure and such activities as coastal management) into ecosystems in order to conserve and develop biodiversity. In this thesis the results of conducted research as well as outsources studies are presented in the form of a synthesis. In this context, the focus has been on integrating knowledge concerning the understanding, use and control of patterns and processes of ecosystems into the planning, the design, construction and maintenance of civil engineering works. Special attention was paid to roads, waterways, road verges, slopes, banks and bridges and viaducts related to the main infrastructure. Much attention is paid not only to the results of the research, but also to integrating the knowledge and understanding developed, in combination with other studies in the same field carried out under the responsibility of the Regional Directorates of Rijkswaterstaat. This thesis was realized in the authors capacity as head (later, former head) of the research section of the environment department of the Road and Hydraulic Engineering Institute and nowadays as coordinator of research into environmental measures for infrastructure; as part-time staff member at the Delft Interfaculty Research Centre for the Sustainable Constructed Environment, especially the research programme 'The Ecological City'; and later as part-time researcher/lecturer at the Faculty of Civil Engineering and Geosciences of the Delft University of Technology. This thesis discusses applied research, which incorporated original research work intended to extend the available knowledge and especially to solve clearly defined practical problems, which in this thesis are considered in their integral context as much as possible. The main research questions, which have been subdivided into subquestions, were in which fields and by which means contributions can be made to reduce adverse effects or to increase the ecological significance of civil engineering works, both existing ones and those to be constructed. Studies have also been made whether it would be possible to formulate on the basis of the research results a set of ecological engineering principles to be used in actual practice. In addition to the systematic collection, analysis and evaluation of data using the available methods and technology in the relevant research fields, research was carried out into the possibilities of creating a synthesis - a combination of not only monofunctional but also multifunctional (interdisciplinary) solutions, since the latter are expected to lead to a larger degree of sustainable development of our actions. Ecological engineering can play an important role in this context. This thesis includes a summary of the knowledge and understanding of the application of ecological engineering in the field of the integration of roads and road systems and natural patterns and processes, the significance of road verges as habitats for plants and animals, the fragmenting effect of roads and the possibilities to adopt mitigating measures, the insertion of roads into the landscape and the management of sandy coasts. The thesis gives also insight into the way the responsibility for environmental and ecological issues in relation to the primary tasks of Rijkswaterstaat has developed within the organisation. This thesis highlights some of the important aspects referred to above concerning motorways and nature, environment and landscape. For aspects about environmental impact assessments (EIA) and motorways, reference is made to the thesis by dr. E.J.J.M. Arts, productgroup leader tracé at the Road and Hydraulic Engineering Institute and as far as the subject compensation is concerned, to the soon to be published thesis written by drs. R. Cuperus, productgroup leader nature and landscape at the Road and Hydraulic Engineering Institute. For the fields of noise and roads and air and roads, reference is made to both existing literature and to upcoming publications within the scope of the ongoing 'Noise Innovation Programme' contracted to the DWW and the recently launched 'Airquality Innovation Programme'.","ecological engineering; civil engineering works; road infrastructure; coastal management","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:b261f904-bdbd-4bce-b9eb-32ad19ad3eb2","http://resolver.tudelft.nl/uuid:b261f904-bdbd-4bce-b9eb-32ad19ad3eb2","Sustainable Chemical Processes and Products. New Design Methodology and Design Tools","Korevaar, G.","Harmsen, G.J. (promotor)","2004","The current chemical industry is not sustainable, which leads to the fact that innovation of chemical processes and products is too often hazardous for society in general and the environment in particular. It really is a challenge to implement sustainability considerations in the design activities of chemical engineers. Therefore, the main question of this thesis is: how can a trained chemical engineer develop a conceptual design of a chemical process or a chemical product in such a way that the final result clearly contributes to sustainable development? This question is answered after a profound discussion about the current chemical engineering practice and its relation to the sustainability debate. This dissertation claims that sustainable development of chemical engineering practices requires a general design methodology accompanied by a set of design tools. Such a combination of methodology and tools does not exist in the chemical engineering field. The author developed a new design methodology and seven new design tools that enable the incorporation of sustainability issues into the design practice of the chemical engineering field. The application and validity of the methodology and its tools are shown in seven, mainly industrial, case studies.","design methdology; design tool; sustainable development; chemical engineering; chemical processes; chemical products","en","doctoral thesis","Eburon, Delft","","","","","","","","Applied Sciences","","","","",""
"uuid:ddd2c83b-d601-4104-8379-637549b630fa","http://resolver.tudelft.nl/uuid:ddd2c83b-d601-4104-8379-637549b630fa","Fischer-Tropsch synthesis revisited; efficiency and selectivity benefits from imposing temporal and/or spatial structure in the reactor","De Deugd, R.M.","Moulijn, J.A. (promotor); Kapteijn, F. (promotor)","2004","","chemical engineering; heterogeneous catalysis; Fischer-Tropsch synthesis; gas-to-liquids; monolithic rReactor; periodic operation","en","doctoral thesis","","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:1d7cb7e4-4ac2-4681-9a05-ff99a5e16827","http://resolver.tudelft.nl/uuid:1d7cb7e4-4ac2-4681-9a05-ff99a5e16827","Risk Analysis for concurrent engineering: HVAC Case","de Vries, D.","","2004","","risk analysis; concurrent engineering","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:c3548438-2b5b-4ca1-90f8-a076f4004b3a","http://resolver.tudelft.nl/uuid:c3548438-2b5b-4ca1-90f8-a076f4004b3a","Het structureren en ondersteunen van de werkwijze binnen het engineeringproces 'marine en offshore' van Croon Elektrotechniek BV","Lodewikus, B.J.C.","","2004","","EOS; engineering; ondersteuning; kwaliteitssysteem; engineeringproces","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:1a9ed13c-63f3-4976-a656-2112c8b6d72e","http://resolver.tudelft.nl/uuid:1a9ed13c-63f3-4976-a656-2112c8b6d72e","Catalysis engineering on three levels","Moulijn, J.A.; Perez-Ramirez, J.; Van Diepen, A.; Kreutzer, M.T.; Kapteijn, F.","","2003","The relevance of levels in space and time for chemical engineering are discussed. Catalysis Engineering is introduced as an emerging new discipline. In Catalysis Engineering three levels can be distinguished: the microlevel focusing on molecules and catalytic sites, the mesolevel focusing on the catalyst particle and the catalytic reactor, and the macrolevel considering the process as an integrated entity. On the level of particle and reactor fascinating developments are visible in the field of structuring of the space. A good example is the monolithic reactor. With the hydrogenation of alpha-methylstyrene as an example, it will be shown that structured reactors allow decoupling of hydrodynamics and chemical kinetics. This implies an extra degree of freedom. From a chemical engineering point of view the intrinsic scaleability of these reactors is intriguing. A case study on nitrous oxide abatement exemplifies the three-level catalysis engineering approach.","catalysis engineering, monolithic reactor, multilevel approach","en","journal article","De Gruyter","","","","","","","","Applied Sciences","","","","",""
"uuid:49a2bfdd-3200-4e53-8189-87f8073553b9","http://resolver.tudelft.nl/uuid:49a2bfdd-3200-4e53-8189-87f8073553b9","Coordinating distributed work: Exploring situated coordination with gaming-simulation","van Laere, J.","Sol, H.G. (promotor)","2003","Organizational work has become more and more distributed nowadays. Information and communication technologies (ICT) provide opportunities to improve coordination of distributed work, but in practice many organizations struggle with integrating new organizational structures, new work practices and ICT. In this dissertation we present a design approach for improving the coordination of distributed work. First we develop an integrated view on coordination, based on observations of current coordination practices at the Amsterdam Police Force and on a literature study of various theoretical perspectives from disciplines like organization science, information systems research, group dynamics and social psychology. In the coordination framework we distinguish 4 main coordination choices for employees at the group level (concerning composition, commitment, contact and content) and 4 related coordination choices for managers at the organizational level (concerning competence, cohesiveness, connection and context). These choices enable us to explain why ICT both enhance and complicate coordination of distributed work. Potentially, ICT has a positive impact on the dimensions of composition and contact and a negative impact on the dimensions of commitment and content. But the success or failure of ICT supported coordination largely depends on how employees and managers apply and use ICT. Consequently a neutral but critical attitude towards ICT support is needed. To improve coordination we apply paradoxical guidelines that take into account the dual impacts of ICT and a multitude of other influencing factors. In simulation games we enable organizational employees to explore future coordination alternatives and to gain experience in making situated coordination choices. The validity and usefulness of this design approach has been explored in two action research studies at the Amsterdam Police Force.","coordination; distributed work; distributed groups; virtual groups; gaming-simulation; gaming; computer supported cooperative work; business engineering; organization science","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:0ecbaf91-2a47-414f-8a48-b097379426ef","http://resolver.tudelft.nl/uuid:0ecbaf91-2a47-414f-8a48-b097379426ef","Hydrodynamics of Taylor Flow in Capillaries and Monolith Reactors","Kreutzer, M.T.","Moulijn, J.A. (promotor); Kapteijn, F. (promotor)","2003","","chemical engineering; reactors; hydrodynamics; monoliths; multiphase flow","en","doctoral thesis","Delft University Press","","","","","","","","Applied Sciences","","","","",""
"uuid:6c344a21-e476-4bad-aeaf-911ca78df49f","http://resolver.tudelft.nl/uuid:6c344a21-e476-4bad-aeaf-911ca78df49f","Rock expansion and compaction at the marker scale in gas producing reservoirs","Ferronato, M.","Verruijt, A. (promotor); Gambolati, G. (promotor)","2003","","Reservoir engineering; finite elements; iterative solvers","en","doctoral thesis","Delft University Press","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:c61f0dca-bd85-42ae-bb55-0b0e38bbba40","http://resolver.tudelft.nl/uuid:c61f0dca-bd85-42ae-bb55-0b0e38bbba40","Facilitating the development of design support software by abstract prototyping","Opiyo, E.Z.","Horváth, I. (promotor)","2003","","CAD/CAE/CAM; engineering software development; quality assurance","en","doctoral thesis","","","","","","","","","Industrial Design Engineering","","","","",""
"uuid:304fa85d-bc41-46d3-948c-0e91bd91a6ab","http://resolver.tudelft.nl/uuid:304fa85d-bc41-46d3-948c-0e91bd91a6ab","Numerical modelling of vanes and screens; development of vanes and screens in Delft3D-MOR","Flokstra, C.; Jagers, H.R.A.; Wiersma, F.E.; Mosselman, E.; Jongeling, T.H.G.","","2003","","bed vanes, screens; river morphology; river flow; river engineering; river management; numerical modelling","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:920581dd-e9f1-4beb-bcac-4524a1ed6404","http://resolver.tudelft.nl/uuid:920581dd-e9f1-4beb-bcac-4524a1ed6404","Design of open-channels and hydraulic structures","Ankum, P.","","2002","Lecture note on open channel hydraulics, hydraulic structures, regulators, weirs, drop structures and stilling basins.","hydraulic engineering; open channel flow; hydraulic structures; drop structures; lecture notes ct3410","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:d3aa81cf-c0ed-4f8d-a9be-de78120763c8","http://resolver.tudelft.nl/uuid:d3aa81cf-c0ed-4f8d-a9be-de78120763c8","Cost effective management control of capital assets: An integrated life cycle management approach","Stavenuiter, J.","Hengst, S. (promotor); Sol, H.G. (promotor)","2002","","Asset management control cost-effectiveness; system effectiveness; life cycle management; material logistics; integrated logistics support; systems engineering and management; performance service contract; life cycle cost; information and communication technology; ships; navy; defense systems","en","doctoral thesis","Asset Management Control Research Foundation","","","","","","","","Mechanical Maritime and Materials Engineering","","","","",""
"uuid:1093e517-2a6a-4ab7-acb7-898febb9ef1b","http://resolver.tudelft.nl/uuid:1093e517-2a6a-4ab7-acb7-898febb9ef1b","STORM-Rhine, main report: Executive summary","Heun, J.C.; de Groen, M.M.; Werner, M.","","2002","","simulation game; roleplay; participatory decision-making; river functions; stakeholder interests; river engineering; river management; floodplain management; institutional arrangements; biological; hydraulic and morphological processes; spatial planning and land use","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:6fa840d2-bd96-46f6-95a5-12e481ee642c","http://resolver.tudelft.nl/uuid:6fa840d2-bd96-46f6-95a5-12e481ee642c","Subcontracting engineering for a multinational shipbuider","van der Giessen, P.J.","","2002","","Subcontracting; engineering; multinational; shipbuider","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:6d64f4e6-f6d5-4e2a-87d9-e8f030d765f9","http://resolver.tudelft.nl/uuid:6d64f4e6-f6d5-4e2a-87d9-e8f030d765f9","Finite-element modelling of stress development and fault reactivation in and around a producing gas reservoir: quantification of calculation results in DIANA","Mulders, FMM (TU Delft Old - CITG Section Engineering Geology)","Hendriks, M.A.N. (editor); Rots, J.G. (editor)","2002","Stress changes related to the depletion of gas reservoirs in the northern Netherlands can lead to small seismic events. Field data analysis makes it very likely that these events are the result of reactivation of existing faults or joints in or near the reservoirs. DIANA is used to model 3D gas reservoirs, in order to analyse stress development and fault reactivation during gas depletion. The models described in this paper are 12,000 x 12,000 x 5000 m and consist of approximately 59,380 TE12L- and T18IF-elements. Calculation results are analysed in terms of relative shear displacements (RSD), stress paths and mobilised shear capacity (MSC). Newly developed and complex formulas for MSC are successfully applied by means of the 'Results calculate expression.'-option in Femview. It shows the possibility of implementing very complicated formulas in Femview. Modelling of the subsurface is a data-limited problem. The presented quantification methods are used to choose appropriate values for strength and pore pressure development of the interface elements for modelling of the fault. An application example illustrates the use of the methods and is supported by field data and earlier research work.","Earthquake Engineering","en","conference paper","CRC Press / Balkema - Taylor & Francis Group","","","","","","Campus only","","","","Old - CITG Section Engineering Geology","","",""
"uuid:276fcdbf-9c71-4175-879c-176102028e08","http://resolver.tudelft.nl/uuid:276fcdbf-9c71-4175-879c-176102028e08","The Delft-Java Engine","Glossner III, C.J.","Vassiliadis, S. (promotor)","2001","In this dissertation, we describe the DELFT-JAVA engine - a 32-bit RISC-based architecture that provides high performance JAVA program execution. More specifically we describe a microarchitecture that accelerates JAVA execution and provide details of the DELFT-JAVA architecture for executing JAVA Virtual Machine bytecode. The basic architecture implements a Media Processor with Signal Processing capabilities. The perspective of the approach is that to maximally accelerate a compiled application, the machine language should accurately reflect the type of operations the compiler specifies. Except where JAVA Virtual Machine operations are unusually complex, we prefer to allow the compiler to optimize directly to the implementation. This is independent of any particular machine organization. The architecture is then a superset of the JAVA Virtual Machine and provides operations that are necessary for system execution (e.g., I/O, supervision, etc.). Rather than just supporting the JAVA Virtual Machine, the architecture takes a more general purpose approach in that it also is intended to be programmed from a number of additional high-level languages including C and C++. Furthermore, we introduce the concept of JAVA dynamic instruction translation, a new approach to JAVA hardware acceleration. In hardware assisted dynamic translation, JAVA Virtual Machine instructions are translated on-the-fly into the DELFT-JAVA instruction set. The hardware requirements to perform this translation are not excessive. Consequently, support for JAVA language constructs are also incorporated into the processor's Instruction Set Architecture. This technique allows application level parallelism inherent in the JAVA language to be efficiently utilized as instruction level parallelism. In addition to dynamic translation, a special Link Translation Buffer (LTB) can be used to improve the performance of dynamic linking. In addition, there are some key organization structures which we deem appropriate to provide architectural support for including: a) synchronization for multithreaded organizations, b) garbage collection, c) array bounds checking, d) real-time caches, e) multiple machines which can time-share the same datapath (e.g., the JAVA Virtual Machine and Media Processing functions), and f) vector/dsp operations. By building several models of the DELFT-JAVA engine, we were able to characterize performance metrics of kernels executing on our processor. We found that when compared to realizable stack-based machines, our techniques could improve performance by 2.7x. Furthermore, by converting stack-based dependencies into pipeline dependencies, we showed that out-of-order superscalar machines could remove up to 60% of the hazards.","computer arithmetic; computer design and engineering; multimedia enhancements; hardware accelerators; multimedia processors; multimedia architecture; java processor","en","doctoral thesis","Delft University Press","","","","","","","","Information Systems and Technology","","","","",""
"uuid:066fec4c-5b7d-466f-bca1-7ea64b4ace15","http://resolver.tudelft.nl/uuid:066fec4c-5b7d-466f-bca1-7ea64b4ace15","Designing electronic intermediaries: An agent-based approach for designing interorganizational coordination mechanisms","Janssen, M.F.W.H.A.","Sol, H.G. (promotor)","2001","","Business engineering; agent-based simulation; coordination; information and management; electronic intermediation; decision support","en","doctoral thesis","","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:fa54d9a3-e52b-42af-a76e-28b5a64da764","http://resolver.tudelft.nl/uuid:fa54d9a3-e52b-42af-a76e-28b5a64da764","Introduction to coastal engineering","D' Angremond, K.; Pluim-van der Velden, E.T.J.M.","","2001","Lecture notes on genesis of the coastline, climatology, oceanography, coastal morphology, coastal formations, coastalzonde management, tidal inlets and estuaries, pollution and density problems, practical problems and common solutions.","coastal engineering; waves; coastline; coastal structures; lecture note ct4300","en","lecture notes","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:862e5c0b-6299-4046-a05f-e7ed16d1603e","http://resolver.tudelft.nl/uuid:862e5c0b-6299-4046-a05f-e7ed16d1603e","Waterbouwkundige kunstwerken - eilanden in de IJszee","Vrijling, J.K.","","2000","Overzicht van kunstmatige eilanden t.b.v. de oliewinning in arctische gebieden (rond de Noordpool, Beaufort Sea). Includes a risk analysis for such an island","artificial island; Beaufort Sea; risk analysis; ice engineering","nl","lecture notes","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:818e5944-727e-4cc3-a836-9744d1a11efd","http://resolver.tudelft.nl/uuid:818e5944-727e-4cc3-a836-9744d1a11efd","Value pricing on the I-15 freeway: Willingness to pay for improved travel service","Van Amelsfort, D.H.; Lindveld, D.R.S.; Bovy, P.H.L.","","2000","In San Diego, California, a value pricing project has been implemented in order to make better use of the existing reversible HOV-facility on Interstate 15, just north of San Diego. In this project, paying solo drivers are allowed to use the Express Lanes. These drivers experience the benefits of free-flow travel instead of the heavily congested traffic situations on the main lanes. The price for using the Express Lanes is determined dynamically and depends on the flow of traffic on these lanes. The objectives of the research presented in the report are: (1) to determine if the project has a congestion relieving effect for the main lanes, (2) how travelers decide between the different travel options in the 1-15 corridor. Using the available historical traffic data, changes in traffic conditions on the 1-15 main lanes were examined. The project does not seem to have a congestion relieving effect. The number of participant is small and there is almost always latent demand. In order to determine how people choose between the different travel options, travel time savings for the Express Lane users were determined. The travel time savings were calculated from loop detector speed at different cross-sections and reach values up to 18 minutes. The estimated travel time savings were then used to estimate mode choice models which explain the choice behavior of travelers between spending time by traveling on the main lanes and spending money by traveling on the Express Lanes. The choice models show that wealthier people, people with a higher level of education, home owners, and woman are more likely to pay for the use of the Express Lanes. The value-of-time of program participants is approximately $31.00 per hour for commuters and $71.00 per hour for non-commuters.","motorway traffic; traffic engineering; pay-lanes","en","report","Delft University of Technology, Faculty Civil Engineering and Geosciences","","","","","","","","Civil Engineering and Geosciences","Transport and Planning","","","",""
"uuid:6a62d6fa-cbcc-4c38-af8a-027c3d191a9d","http://resolver.tudelft.nl/uuid:6a62d6fa-cbcc-4c38-af8a-027c3d191a9d","Statistical methods for the risk-based design of civil structures","Van Gelder, P.H.A.J.M.","Vrijling, J.K. (promotor)","2000","","risk-based design; uncertainty analysis; probability engineering; statistical data analysis","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:9219c325-e0ce-4d02-8dd4-375a3b70bce7","http://resolver.tudelft.nl/uuid:9219c325-e0ce-4d02-8dd4-375a3b70bce7","Concurrent engineering for integrated shipbuilding","van der Bles, G.; Dirkse, C.","","2000","","Concurrent; engineering; for; integrated; shipbuilding","","other","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:f2e6f015-e11f-43b5-85b8-5de9218cec30","http://resolver.tudelft.nl/uuid:f2e6f015-e11f-43b5-85b8-5de9218cec30","Finite element models for the steady state analysis of moving loads","Kok, A.W.M.","","2000","The analysis of structures subjected to fast moving loads is a subject of growing interest in railway and pavement engineering. The applications of transient analyses using finite element models, however, are still very limited. The faster a load moves the more elements we need to model the structure. Even at fast workstations and main frame computers a moderate accurate analysis requires a huge amount of computer time. Many problems can be solved more efficient by application of a steady state analysis using a moving reference system. Based upon this formulation we will develop finite element models that travel together with the moving loads. Such an analysis can be performed with the computer power and execution time necessary for the solution of a common static problem, thus at a normal PC. Especially in the design phase such an analysis is very attractive.","moving loads; finite elements; railway engineering","en","journal article","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Railway Engineering","","","",""
"uuid:eec57eb2-31ee-4b7b-9036-344dcc54ebfe","http://resolver.tudelft.nl/uuid:eec57eb2-31ee-4b7b-9036-344dcc54ebfe","Optimization of an embedded rail structure using a numerical technique","Markine, V.L.; De Man, A.P.; Esveld, C.","","2000","This paper presents several steps of a procedure for design of a railway track aiming at the development of optimal track structures under various predefined service and environmental conditions. The structural behavior of the track is analyzed using a finite element model in which the track and a moving train are incorporated. Parameters of the optimum track are determined by applying a numerical optimization technique. The optimization method employed here uses Mutipoint Approximations based on Response Surface fitting (MARS). To demonstrate the robustness of the procedure, it is applied to a problem of optimal design of an innovative railway track for high-speed trains - a so-called Embedded Rail Structure. Requirements for the optimal design are related to the wear of the rails and wheels and the level of acoustic noise produced by a moving train. To obtain the optimal design, component dimensions and mechanica properties of the track are varied. Results of the optimization are presented and discussed.","Railway Engineering; Numerical Optimization; Dynamics","en","journal article","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Railway Engineering","","","",""
"uuid:aeda5e97-9265-4487-8cd4-a076344fb760","http://resolver.tudelft.nl/uuid:aeda5e97-9265-4487-8cd4-a076344fb760","Safety concepts in land use engineering: The case of underground infrastructures","Beroggi, C.E.G.","","1999","","safety engineering; underground construction","en","book","Delft University Press","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:df8a67a3-08bc-4b37-9597-1f8e3aa586d2","http://resolver.tudelft.nl/uuid:df8a67a3-08bc-4b37-9597-1f8e3aa586d2","Effective lecturing behaviour in English Medium Instruction; A pilot study","Klaassen, R.G. (TU Delft OLD E&SS education center FOCUS); Snippe, Joke","","1999","Today, the expansion of English education between non-native speakers with different language backgrounds requires insight into the problems encountered in the multicultural classroom and the consequences of English-medium instruction for local students as well as students of other nationalities. As English becomes the language of communication it may cause on the one hand an increase in lecturers'workload and adversely affect their lecturing behaviour and on the other hand it may affect students' workload and study behaviour and workload, resulting in a loss of academic achievements (Jochems et.all 1994). Both English speaking communities as well as other European Communities are aware of the necessity for research into the ever increasing activities in the area of internationalisation. In this booklet you will find 4 qualitative case studies, describing the nature of effective lecturing behaviour in English-medium instruction at TU- Delft.","English medicum instruction; higher education; engineering education","en","book","Delft University Press","ISBN: 90-407-1882-2","","","","uuid:033f4b8c-a34f-4ec5-8cd2-71c7ca085db0 in TU Delft repository","Campus only","","","","OLD E&SS education center FOCUS","","",""
"uuid:8cfa5f35-2117-4ae8-b0a1-27dbc095937c","http://resolver.tudelft.nl/uuid:8cfa5f35-2117-4ae8-b0a1-27dbc095937c","Multimedia Hardware Accelerators","Hakkennes, E.A.","Vassiliadis, S. (promotor)","1999","","computer arithmetic; computer design and engineering; multimedia enhancements; hardware accelerators; multimedia processors; multimedia architecture","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:cf2383a2-3b96-4b7e-b51f-3e0f0ecd69bf","http://resolver.tudelft.nl/uuid:cf2383a2-3b96-4b7e-b51f-3e0f0ecd69bf","Development of a Teaching Exercise for the Design of a Revetment","Jokowinarno, D.","Verhagen, H.J. (contributor); De Vries, W.T. (contributor); Rijkswaterstaat","1999","Objectives of this work are to: a. Identify a problem related with coastal defence. b. Understand how to determine the boundary conditions and apply this knowledge. c. Understand the choice ofthe solution. d. Understand how to design a simple revetment with rip-rap as one of the coastal defences. e. To develop educational material to be used at university level in Indonesia.","indonesia; education; coastal engineering","en","report","IHE Delft","","","","","","","","","","","","KWP-collection",""
"uuid:66fd16dd-2761-4ccd-96f0-d660ba11c852","http://resolver.tudelft.nl/uuid:66fd16dd-2761-4ccd-96f0-d660ba11c852","Sustainable transfer of coastal engineering knowledge at post graduate level","Verhagen, H.J.; De Vries, W.S.","","1999","Practical problems in the transfer of knowledge and skills to coastal engineers in training, with focus on the training of coastal engineers from developing countries and other countries in transition. The difference between the training of scientists and engineers.","Coastal Engineering; capacity building; training; education","en","conference paper","Copedec","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:7e0b633e-c11d-4da2-842c-c64a4ee0991e","http://resolver.tudelft.nl/uuid:7e0b633e-c11d-4da2-842c-c64a4ee0991e","Selected topics in identification, modelling and control: Progress report on research activities in the mechanical engineering systems and control group","Bosgra, O.H.; Van den Hof, P.M.J.; Scherer, C.W.","","1998","","systems engineering","en","book","Delft University Press","","","","","","","","Mechanical, Maritime and Materials Engineering","","","","",""
"uuid:db69eee4-c133-4fc7-a6e5-cf0701722562","http://resolver.tudelft.nl/uuid:db69eee4-c133-4fc7-a6e5-cf0701722562","Coastal Engineering. Volume I","D' Angremond, K.; Somers, C.M.G.","","1998","Natural system, coastal dynamics, climatology, oceanography, morphology. Coastal formations, Coast and culture, The Netherlands.","coastal engineering; coastal morphology; coastal protection; lecture note CTwa4300","en","lecture notes","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:59163e85-0c3d-4661-829a-2e62e0f749c6","http://resolver.tudelft.nl/uuid:59163e85-0c3d-4661-829a-2e62e0f749c6","A macroscopic model for multiple user-class traffic operations: Derivation, analysis and numerical results","Hoogendoorn, S.P.; Bovy, P.H.L.","","1998","In this report we derive a macroscopic Multiple User-Class traffic model from mesoscopic principles. These principles yield equilibrium relationships between traffic density and equilibrium velocities as a function of the current traffic conditions, the traffic composition, and the distribution of user-class dependent desired velocities, rather than these relations need to be defined exogenously. These relations encompass contributions of drivers accelerating towards their user-class specific desired velocity on the one hand, and contributions resulting from interaction between vehicles of the same or different classes on the other hand. Additionally, the velocity variance variable is introduced describing deviations from the average speed within the user-classes. We discuss several mathematical properties of the MUC equations. One of the results is an alternative model formulation, namely using the so-called conservative variables desity, momentum and energy, rather than the primitive variables density, velocity and velocity variance. Using this formulation, several new approaches are derived to numerically approximate solutions of the flow model. We discuss first results from macroscopic simulation using the developed multiple user-class traffic flow model. The simulation results are employed to investigate whether fundamental traffic flow model-equations hold. It is concluded that the MUC-model satisfies the anisotropy condition, the 'invariant personality condition', and the 'unaffected slow vehicles' condition. A test case illustrates the self-formation of congestion.","traffic engineering","en","report","Delft University of Technology, Faculty Civil Engineering and Geosciences","","","","","","","","Civil Engineering and Geosciences","Transport and Planning","","","",""
"uuid:42a7fe73-299d-47ac-8d01-44150e40bd27","http://resolver.tudelft.nl/uuid:42a7fe73-299d-47ac-8d01-44150e40bd27","Anisotropic Geotechnical Properties of a Glacially Overconsolidated and Fissured Clay; Anisotrope Geotechnische Eigenschappen van een Glaciaal Overgeconsolideerde en Gescheurde Klei","Schokking, F.","Niewenhuis, J.D. (promotor); Verruijt, A. (promotor)","1998","","geotechnics; engineering geology","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:ab665899-2b05-45e4-ae43-b9295a1d2c3f","http://resolver.tudelft.nl/uuid:ab665899-2b05-45e4-ae43-b9295a1d2c3f","Addition related arithmetic operations with threshold logic","Cotofana, S.D.","Vassiliadis, S. (promotor)","1998","","computer arithmetic; computer design and engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:dce52351-ed13-4777-86a7-2febac7485e8","http://resolver.tudelft.nl/uuid:dce52351-ed13-4777-86a7-2febac7485e8","Recent developments in coastal engineering","Kohlhase, S.; Kao, C.C.","Rijkswaterstaat","1998","The Purpose of Coastal and Marine Research in Germany (Rolf Peter RANDL) Topic I, Coastal Protection Coastal Protection and its Management in Germany (Heie Focken ERCHINGER) The Scientific and Technical Development of Marine Technology in the Central Weather Bureau (Beng-Chun LEE) Climate Impact Research for the German Coast of the Baltic Sea (Werner ZIELKE) Integration of Coastal Protection in Germany into a Coastal Zone Management (Hans KUNZ) The Ocean Space Utilization and Monitoring Program in the Western Coast of Taiwan (Hwung-Hweng HWUNG Ruey-Chy KAO) Optiniised Design of Land Reclamation Fields for Sustainable Foreland Development (Nicole VON LIEBERMANN Andreas MATHEJA Horst SCHWARZE) High Water Protection in Coastal Towns of Mecklenburg-Vorpommern (Thomas ZARNCKE Barbel KOPPE) Topic II, Field Investigations The Effect of the Irregularity of Waves for the Design of Coastal Structures (Karl-Friedrich DAEMRICH) Hydrodynamic Impact on Cliff Coast Areas of the Baltic Sea on the Basis of Directional Wave Measurements (Peter FROHLE Thomas FITTSCHEN ) Measurement of Directional Waves by Wave Gauge array and Buoy (Chia Chuen KAO Hwa CHIEN Heng Haur CHOW Yean Bin LIN Chao Hui LIN) Accuracy Analysis of SURFER"" Contouring of Bar-type Coastal Topography (Shiahn-Wern SYHUE Chung-Pan LEE) Recent Developments in Shallow Water Wave Prediction (Heinz GÜNTHER) Forecasting of Typhoon Waves for a Harbor at Eastern Coast of Taiwan (Laurence Zsu-Hsin CHUANG Chihfeng KUAN Dong Jiing DOONG) Topic Ill, Simulation Methods Aspects of Modelling Sediment Transport in lnstationary Flow (Ulrich ZANKE ) Cross-Shore Sediment Transport - Comparison of Basic Approaches and Limitations - (Hans-Henning DETTE ) DRBEM Analysis of Combined Wave (Ming-Chung LIN ) Refraction and Diffraction in the Presence of Nien-Chia Hu Currents (Sung-Shan HSIAO ) A Numerical Model for Non-linear Interaction of Water Waves with Submerged Obstacles (Robert R. HWANG Y.C. SUE ) Coupling of Numerical Wave and Current Models (Klaus-Peter HOLZ Peter MILBRADT) A Second-Order Solution of the Flap Wavemaker Problem (Jaw-Fang LEE Cheng-Chi Llu Yuan-Jyh LAN) Activities of Coastal Development in Taiwan (Yen-Sun Hsu )","coastal engineering","en","report","Universität Rostock, Institüt für Wasserbau","","","","","","","","","","","","KWP-collection",""
"uuid:b6156ad4-9b56-463a-a82a-ec11fa70cbcc","http://resolver.tudelft.nl/uuid:b6156ad4-9b56-463a-a82a-ec11fa70cbcc","Review and selection of methods for structural reliability analysis","Van Eekelen, A.J.","","1997","To select a method for analyzing structural reliability problems, including pptimization under reliability constraints, a literature survey was performed. In this review the most frequently used and most generally applicable methods are described. An extensive list of references is included. The methods described here are compared on the basis of available information in the literature, and not on experience gained with these methods. The criteria for comparison are: - numerical efficiency - accuracy - general applicability For structural optimization under reliability constraints numerical efficiency is especially important. This is because multiple so-called limit states generally have to be evaluated at each analysis step. The method that looks most promising with respect to the above criteria is the Galerkin based response surface method. It is both efficient, due to the explicit nature of the response surface, and accurate due to the rigorous mathematical basis. Finally, an example of a beam with random flexural rigidity is analyzed using this method. Although no structural optimization is done in this example, the choice of method seems justified.","mechanics of engineering structures","en","book","Delft University Press","","","","","","","","Aerospace Engineering","","","","",""
"uuid:ca26fa79-b6ce-49c3-b15e-a6574d9263b0","http://resolver.tudelft.nl/uuid:ca26fa79-b6ce-49c3-b15e-a6574d9263b0","Car-following under non-congested and congested conditions","Dijker, T.; Bovy, P.H.L.; Vermijs, R.G.M.M.","","1997","In traffic flow analysis several regimes are distinguished, such as congested and non-congested flow conditions. Indications exist that driving behavior differs by regime, and that it may change discontinuously between regimes. In contrast, most traffic flow models used today basically assume the same car-following behavior irrespective of the traffic flow regime. It is hypothesized that because of this deficiency, these models do not always perform satisfactorily. To clarify this issue, differences in car-following between congested and non-congested flow are analyzed with data from two sites on Dutch freeways. It is shown that, at the same speeds, passenger car drivers follow with smaller headways in non-congested flow than in congested flow. Car-following of truck drivers does not show differences between regimes. Microscopic distance gap - speed models are established for several road user classes, valid for each of the two flow regimes. To show the improvements resulting from these new microscopic relationships, the latter are implemented in a micro simulation model (FOSIM) with which macroscopic patterns in traffic flow are modeled. The macroscopic findings produced with the regime specific car-following rules show a considerable improvement in modeling performance.","traffic engineering; traffic flow theory; transportation management","en","report","Delft University of Technology, Faculty Civil Engineering and Geosciences","","","","","","","","Civil Engineering and Geosciences","Transport and Planning","","","",""
"uuid:dc89868a-1825-400f-b488-40596684881b","http://resolver.tudelft.nl/uuid:dc89868a-1825-400f-b488-40596684881b","A Design Coordination Approach to Design For X","Tichem, M.","Reijers, L.N. (promotor)","1997","","engineering design; design for x; design coordination","en","doctoral thesis","","","","","","","","","Mechanical Maritime and Materials Engineering","","","","",""
"uuid:97b0e489-4136-42e1-bdd0-763031fb429a","http://resolver.tudelft.nl/uuid:97b0e489-4136-42e1-bdd0-763031fb429a","An environment to support flexible information modeling","Dahanayake, A.N.W.","Sol, H.G. (promotor); Dietz, J.L.G. (promotor)","1997","","Information Systems Development Methods; Method Engineering; Meta Modeling; Computer Aided Systems Engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:a2b4fa97-207a-40c2-96a2-125db5e6a1a3","http://resolver.tudelft.nl/uuid:a2b4fa97-207a-40c2-96a2-125db5e6a1a3","Architecture and construction principles for Computational Fluid Dynamics software for engineering in industry","Vogels, M.E.S.","","1997","For flow simulation around (parts of) aerospace vehicles, aerospace industry needs CFD software. For users in industry, not only the functionality of the software is relevant. Timely availability and cost of the first version and later versions are other relevant factors. These factors are represented in the software characteristics timeliness, testability, adaptability, and accessibility. Except for the latter, these software characteristics are by a great extent determined by the structure of the software. The structure of software is created in the architectures of the various aspect-systems and in the construction of the software. The central question of the thesis is How to achieve a structure of CFD software for engineering in industry suited for support of timeliness, testability, and adaptability? The central question is answered in the form of architecture and construction principles, which are basic forms, rules, or recommendations with respect to architecture and construction. Major principles are to maintain the structure of the mathematics in the structure of the CFD software, to design for expected changes, and to incorporate exception handling and other standard sound software approaches. The set of architecture and construction principles has been developed and applied during a project for the iterative development of a specific CFD flow solver, SOLEQS. The flow solver is included as a demonstrator of application of the architecture and construction principles. The relevance of the current work is that application of the principles can support research organisations to deliver innovative CFD software that fulfills industry's requirements for engineering tools. Such software then acts as carrier for knowledge transfer from research organisations to industry.","Algorithms; Architecture (computers); Computational Fluid Dynamic; Computational grids; Computer systems design; Data structures; Multidisciplinary design optimization; Navier-Stokes equation; Software engineering; Software development tools; User requirement; Turbulence model","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:761221b9-670b-4e04-866a-bc1c74b774e8","http://resolver.tudelft.nl/uuid:761221b9-670b-4e04-866a-bc1c74b774e8","Interface Control and Software Engineering: A formal approach","Brink, K.","van Katwijk, J. (promotor)","1997","","software development; real-time software; control engineering; formal specification","en","doctoral thesis","Delft University Press","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:19238c50-346a-4b1d-966c-f8051ae1c8f6","http://resolver.tudelft.nl/uuid:19238c50-346a-4b1d-966c-f8051ae1c8f6","Co-ordinated traffic control in freeway corridors: A proposed evaluation approach","Hoogendoorn, S.P.; Bovy, P.H.L.; Van der Zijpp, N.J.","","1997","In the course of the Telematics implications Programme Transport of the European Commission Fourth Framework Research Programme much attention is devoted to evaluation and demonstration. This report is part of the DACCORD project TR1017, devoted to the development and application of co-ordinated traffic control in freeway corridors. The report presents an evaluation plan for the Fourth Framework programme DACCORD. An extensive methodology has been applied to prepare a systematic and comprehensive evaluation plan. It contains an analysis assessment objectives, specification of performance indicators enabling evaluation at distinct levels of assessment (i.e. technical level, user-acceptance, impact analysis, and socio-economic assessment) and a description of various tools for validation. The plan has been developed to be site-independent to a large extent, thereby maximising the potential for cross-comparison, by proposal of common verification and demonstration plans for distinct sites. Additionally, the evaluation plan enables harmonisation of results from other European ATT-projects.","traffic engineering; traffic control; transportation management","en","report","Delft University of Technology, Faculty Civil Engineering and Geosciences","","","","","","","","Civil Engineering and Geosciences","Transport and Planning","","","",""
"uuid:d30f6813-d039-4a3a-8f7d-a79301e1ac13","http://resolver.tudelft.nl/uuid:d30f6813-d039-4a3a-8f7d-a79301e1ac13","Network middelware illustrated for enterprise enhanced operation","Loeve, W.; van der Ven, H.; Vogels, M.E.S.; Baalbergen, E.H.","","1997","Enterprises are confronted with the challenge to lower cost of product engineering. Engineers enter and leave enterprises. Much engineering know-how can be conserved for use by successive generations of engineers in documented engineering procedures, in software for simulation and in the supporting documents and simulation related data. IT can enhance enterprise operation by giving engineers working for the enterprise, easy access to the engineering information, comprising the enterprise know-how. This requires a combination of distributed and centralised computing, a suitable network strategy, and IT tools for management, control and use of the conserved enterprise information. In the paper the considerations and the technical principles are illustrated by examples from two applications: a national virtual centre for Computational Huid Dynamics for engineering and an IT framework for distributed multi-discipline design, analysis and optimisation of industry products.","enterprise network; middleware; IT; enterprise automation; engineering","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:8f8623d5-94f7-4000-8bdb-6f379bea83da","http://resolver.tudelft.nl/uuid:8f8623d5-94f7-4000-8bdb-6f379bea83da","Design of cut-outs in shell structures","Heerschap, M.E.","Rothwell, A. (promotor); Van der Schee, P.A. (promotor)","1997","","aerospace engineering; CAD; finite elements","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:94d2cc9b-d4ac-4d67-b181-44bedf3f09a6","http://resolver.tudelft.nl/uuid:94d2cc9b-d4ac-4d67-b181-44bedf3f09a6","High performance execution engines for instruction level parallel processors","Phillips, J.E.","Vassiliadis, S. (promotor)","1997","","computer architecture and engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:401b88f5-a1d7-46a2-a08a-850ad66e28b8","http://resolver.tudelft.nl/uuid:401b88f5-a1d7-46a2-a08a-850ad66e28b8","Dynamica 3-A: Lecture Notes wb1303","Meijers, P.","","1997","Lecture Notes for course wb 1303 Dynamica 3-A, Faculty 3me/Mechanical Engineering, TU Delft. Contents: Continuous systems; Dynamics of a reciprocating engine; Non-linear systems; Kinematics and dynamics of multi-body systems; Exercises.","dynamics; reciprocating engine; non-linear dynamics; multi-body systems; continuous systems","nl","lecture notes","TU Delft","","","","","","","","Mechanical, Maritime and Materials Engineering","Precision and Microsystems Engineering","","","",""
"uuid:1752d999-39c3-4c94-8d36-e628a7be1afa","http://resolver.tudelft.nl/uuid:1752d999-39c3-4c94-8d36-e628a7be1afa","Behaviour oriented model for the evaluation of long-term lagoon-coastal dynamic interaction along the Po River Delta","Stive, M.J.F.; Ruol, P.; Capobianco, M.; Buijsman, M.","","1997","","Coastal engineering Mathematical models Rivers Sediment transport Tides Lagoon coastal dynamics 407.3 (Coastal Engineering) 921 (Applied Mathematics) 444.1 (Surface Water) 631.3 (Flow of Fluid Like Materials) 471.4 (Seawater, Tides and Waves)","en","conference paper","American Society of Civil Engineers","","","","","","","","","","","","",""
"uuid:7f147843-9115-431e-bd9a-2f35ef62b268","http://resolver.tudelft.nl/uuid:7f147843-9115-431e-bd9a-2f35ef62b268","Bar migration and duneface oscillation on decadal scales","Stive, M.J.F.; Guillen, J.; Capobianco, M.","","1997","","Coastal zones Geomorphology Beaches Water waves Duneface oscillation Nearshore morphology Migratory bar system 407.3 (Coastal Engineering) 481.1.1 (Geomorphlogy) 471.4 (Seawater, Tides and Waves)","en","conference paper","Asce","","","","","","","","","","","","",""
"uuid:db25be50-18d0-475f-9117-7b18c21ca0cc","http://resolver.tudelft.nl/uuid:db25be50-18d0-475f-9117-7b18c21ca0cc","Quality control of Li1+dMn2-dO4 spinels with their impurity phases by Jaeger and Vetter titration","Kelder, E.M.; Jak, M.J.G.; Schoonman, J.; Hardgrave, M.T.; de-Andersen, S.Y.","","1997","","Secondary batteries Lithium ion Batterie accumulateur electrochimique Lithium ion Litio ion Electrical power engineering Electrical engineering Applied sciences Electroenergetique Electrotechnique Sciences appliquees Electroenergetica Electrotecnica Cienc","en","journal article","","","","","","","","","","","","","",""
"uuid:ba564f98-144d-4f7f-92a7-7d05c4af934c","http://resolver.tudelft.nl/uuid:ba564f98-144d-4f7f-92a7-7d05c4af934c","Three-dimensional finite element analysis of tunnels and foundations. (Analyse tridimensionnelle aux elements finis de tunnels et de fondations)","Groen, A.E.; De Borst, R.","","1997","","Case study; Civil; Clay; Differential settlement; Drilling; Engineering geology; Europe; finite element analysis; Finite element method; Foundations; Italy; Land subsidence; Monument; Numerical simulation; Pipelaying; Sand; SFS; Soft soil; Stress strain; Structural stability; Three dimensional model; Three dimensionalshape; Tower (building); Tunnel driving; Underground pipe; Underground structure","en","journal article","","","","","","","","","","","","","",""
"uuid:f237bbde-36e6-4bff-a5d1-b26da766efb7","http://resolver.tudelft.nl/uuid:f237bbde-36e6-4bff-a5d1-b26da766efb7","Queuing and convergence properties of a dynamic assignment model for congested networks","Troost, J.F.; Botma, H.; Bovy, P.H.L.","","1996","The growing congestion problems demand a new generation of traffic models that are applicable in the planning and management of infrastructure. The aim of this thesis is the development of a traffic model able to predict congestions and their influence on traffic operation. This model is meant for three areas of applications: research into travellers' reaction to congestion; the planning of scarce infrastructure and the optimisation of the use of scarce road capacity. This thesis has been restricted to traffic operation on motorways. It is assumed that all travellers show the same behaviour. The literature review resulted in the conclusion that the so called dynamic traffic assignment models are able to detect a shortcoming of supply of infrastructure and to give insight in time dependent effects of congestion. Two different groups of traffic models can be distinguished, the traffic assignment models that assign traffic sequential per OD pair and the simulation models that calculate traffic operation on individual vehicle level. The traffic assignment models were chosen for fiirther development because these are expected to be useful both for planning and management, due to the ability to restrain the costs of use of these models by an appropriate choice of the required level of detail. Basis of the model is a dynamic traffic assignment model developed at Delft University of Technology. This model can be seen as an extended version of the existing static assignment models. Time dependent traffic operation in a network is modelled by using sequential time periods. Capacity restraints are introduced by the use of a speed/density relation instead of a speed/flow relation that is customary in static assignment models. An adequate mathematical definition of the model is missing. It is concluded that the original model without the use of a queuing algorithm does not converge in congested situations. A newly developed queuing algorithm gives a realistic representation of congested roadways, especially in those cases where spillback effects appear to upstream bottleneck links. This representation is achieved by the determination of the speed effects on upstream bottleneck links. The speed reducing effects depend on the level of oversaturation of the involved bottleneck. The newly developed queuing algorithm resulted in a better convergence behaviour than the original model (and queuing algorithm). This is shown several elementary test cases that have been investigated with software developed for this purpose. The new developed queuing algorithm resulted also in better solutions. The calculated results match better with the expected results based on traffic flow theory. The applicability of the model remains restrained to situations where spill back effects do not have substanially impact on the route choices and where a restricted level of detail of the results is sufficient for the considered application. Application in the field of traffic management requires more practical research. An approach with simulation models should not be dismissed.","traffic engineering; transportation modeling","en","report","","","","","","","","","Civil Engineering and Geosciences","Transport and Planning","","","",""
"uuid:91e542d8-7db7-4d56-9a38-b77c407b3733","http://resolver.tudelft.nl/uuid:91e542d8-7db7-4d56-9a38-b77c407b3733","Introduction to bed, bank and shore protection","Schiereck, G.J.","","1996","Flow (loads, stability, erosion) Porous flow (general, filters), waves (loads, stability, erosin), ships, protections, construction and maintenance, design.","coastal engineering; revetments; bottom protection; bed protection","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:9438b900-5312-4893-aec3-99740744529f","http://resolver.tudelft.nl/uuid:9438b900-5312-4893-aec3-99740744529f","An assessment of roadway capacity estimation methods","Minderhoud, M.M.; Botma, H.; Bovy, P.H.L.","","1996","This report is an attempt to describe existing capacity estimation methods with their characteristic data demands and assumptions. After studying the methods, one should have a better idea about the capacity estimation problem which can be encountered in traffic engineering. Moreover, decisions to employ a particular method should be made (much) easier since advantages, disadvantages and other aspects concerning the application of the methods are discussed.","traffic engineering","en","report","Delft University of Technology, Faculty Civil Engineering and Geosciences","","","","","","","","Civil Engineering and Geosciences","Transport & Planning","","","",""
"uuid:f182e689-716a-4898-bc5e-02f87a9d73b8","http://resolver.tudelft.nl/uuid:f182e689-716a-4898-bc5e-02f87a9d73b8","Pedoman Teknik Pantai (coastal engineering manual)","Schiereck, G.J.; Verhagen, H.J.","TU Delft and Unesco IHE","1996","Design manual for coastal engineering works with focus on Indonesia.","coastal engineering","en","report","TU Delft and IHE","","","","","","","","","","","","",""
"uuid:a9e57697-6499-4e19-bc01-5234d5a44e17","http://resolver.tudelft.nl/uuid:a9e57697-6499-4e19-bc01-5234d5a44e17","Experimental investigation on the influence of liner non-uniformities on prevailing modes","Parente, C.A.; Rademaker, E.R.; Sarin, S.L.","","1996","From the in-flight measured circumferential modal spectra of the Rolls-Royce Tay 650 engine mounted on the Fokker 100, it was found that the sound field propagating upstream in the inlet is strongly modulated by intercostal hard-walled strips in the lined area, the non-cylindrical geometry of the duct, and the non-axisjnmnetric flow velocity distribution. To study the effect of the modulation of the acoustic field by the hard-walled strips separately, an experimental program in the NLR spinning mode synthesizer was carried out. In the first place, the effect of scattering of modes of low circumferential order in the absence of flow was studied using an array of loudspeakers as noise source. Sound was generated in the frequency range from 400 Hz to 3000 Hz. The target circumferential mode numbers ranged from 0 to 3. Modal scattering caused by simulated hard-walled strips was studied by measuring the incident and transmitted acoustic energy flux is not much influenced by the scattering of the incident modes, whereas the m-mode spectra of the transmitted field clearly show modulation effects caused by the hard-walled strips and the modulation increases with increasing mode number.","acoustic ducts; acoustic measurement; acoustic scattering; damping; data acquisition; duct geometry; engine inlets; frequency sjmthesizers; linings; propagation modes; sound transmission; sound fields; turbofan engines","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:230da395-7069-4569-b183-1c741c15b209","http://resolver.tudelft.nl/uuid:230da395-7069-4569-b183-1c741c15b209","Theory of sound propagation in a flow duct lined with annular segments of porous material","Sijtsma, P.","","1996","A theory is presented to calculate acoustic modes in a circular flow duct lined with porous material. The porous material is divided into annular segments by a rigid structure, which prevents axial sound propagation from one segment into the other. Single modes cannot exist in such a configuration, but it is shown that approximate solutions of the eigenvalue problem can be constructed. A numerical example is given and compared with special cases from the literature.","acoustic ducts; engine values; linings; engine inlets; noise reduction; porous materials; propagation modes; sound transmission","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:e9562632-361f-4d36-b77f-5459d6123cf6","http://resolver.tudelft.nl/uuid:e9562632-361f-4d36-b77f-5459d6123cf6","A pattern directed approach towards an object adaptive decision support environment for water resources management","Liu, Y.","Kopperlaar, H. (promotor); Van der Veer, P. (promotor)","1996","","decision support system; geographical information system; object oriented design; pattern directed analysis; knowledge engineering; water management","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:619457dd-7aa0-4045-9136-87d123012322","http://resolver.tudelft.nl/uuid:619457dd-7aa0-4045-9136-87d123012322","Failure and cracking of Inconel 718 air supply manifold support rods: A service-related contribution to lEPG TA 31","Wanhill, R.J.H.; Boogers, J.A.M.; Huisman, H.N.; Ottens, H.H.","","1996","In 1995 an air supply manifold support rod from a high-performance turbofan engine failed by bending fatigue. The rod material was Inconel 718, operating at about 550° in an air environment. Diagnostic aspects of the failure (fatigue in bending, Stage I and Stage II fatigue fracture characteristics, and interference colours due to fracture surface oxidation) were aided by test results from the European collaborative programme lEPG TA 31: Lifing Concepts for Military Aero-Engine Components. Bending of the rod was caused by relative movement of the inner and outer sections of a connection between the diffuser case air supply manifold, whereby accomodatory swivelling of a spherical ends of the rod in the spherical seatings of the connection was prevented by contact pressure, fretting and binding. A contributory factor is likely to have been decomposition of an anti-galling compound applied to the spherical contact surfaces. This decomposition, and hence loss of function, could have begun at temperatures well below the normal operating temperatures of the rod. Recommendations were made for the alternative anti-galling compounds or a plasma-sprayed coating, which is a less suitable option. It was also recommended to thoroughly inspect the rods in other engines, as an addition to the specified maintenance procedure. This additional inspection was well under way by the beginning of 1996.","bending fatigue; cracking (fracturing); failure analysis; Inconel (trademark); intake systems; manifolds; fractography; rods; metal surfaces; protective coatings; turbofan engines","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:7bd48132-26aa-424b-a6ca-7cea948c9b7b","http://resolver.tudelft.nl/uuid:7bd48132-26aa-424b-a6ca-7cea948c9b7b","Education of coastal engineers for the 50th ICCE","Verhagen, H.J.","","1996","In general the problem in education is that we teach nowadays students the knowledge from five years ago, to be applied in the next 5 to 15 years (I admit, the student of today will have reached his retirement when he will participate in the 50th ICCE, the title is exaggerating reality). When one analyses the developments in the profession, it is clear that teaching present day facts is not very useful. We have to teach approaches, design philosophy, concepts, etc. What the meaning is for education of coastal engineers will be worked out in this paper.","education; coastal engineering","en","conference paper","ASCE","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4e855902-cd08-4fb8-b185-a8c5804f79ac","http://resolver.tudelft.nl/uuid:4e855902-cd08-4fb8-b185-a8c5804f79ac","Pyruvate Metabolism in Saccharomyces cerevisiae","Pronk, J.T.; Steensma, H.Y.; van Dijken, J.P.","","1996","","Yeast; glycolysis; TCA cycle; sugar metabolism; metabolic engineering; pyruvate decarboxylase; pyruvate carboxylase; pyruvate dehydrogenase complex; alcoholic fermentation; Crabtree effect","en","journal article","Wiley","","","","","","","","","","","","",""
"uuid:0ad003ef-aa37-46f3-8215-6f37c83af5da","http://resolver.tudelft.nl/uuid:0ad003ef-aa37-46f3-8215-6f37c83af5da","Lumped Pulses and Discrete Displacements: A Physical Way to Understand Numerical Dynamics","Kok, A.W.M.","Blaauwendraad, J. (promotor)","1995","","nonlinear dynamics; pavement engineering; earthquake analysis","en","doctoral thesis","Delft University Press","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:a45afe83-b58c-4a18-bc9e-83c95a9c5a11","http://resolver.tudelft.nl/uuid:a45afe83-b58c-4a18-bc9e-83c95a9c5a11","Information Systems Management in Complex Organizations","De Wijs, C.","Looijen, M. (promotor)","1995","","information systems management; risk engineering","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:16b23e93-5c81-47c2-862e-d9b894ff1881","http://resolver.tudelft.nl/uuid:16b23e93-5c81-47c2-862e-d9b894ff1881","An algorithm for mesh rezoning with application to strain localization problems","Gutierrez, M.A.; De Borst, R.; Schellekens, J.C.J.; Sluys, L.J.","","1995","","adaptivity techniques; Algorithm; algorithm theory; automatic rezoning; C4185 Finite element analysis; C4240 Programming and algorithm theory; C7440 Civil and mechanical engineering computing; Civil; coarse constant density mesh; curved boundaries; Deformation; finite element; finite element mesh; initial topology; Interpolation; Localization; mechanical; mesh density; mesh generation; mesh rezoning; mesh spacing control; remeshing; Strain; strain localization; strain localization problems; structural engineering computing","en","journal article","","","","","","","","","","","","","",""
"uuid:96f94279-326a-483c-ac1d-c7f9e9226342","http://resolver.tudelft.nl/uuid:96f94279-326a-483c-ac1d-c7f9e9226342","Preliminary Report on The Great Hanshin Earthquake January 17, 1995","Nakamura, H.","Toki, K. (contributor); Ishihara, K. (contributor); Yasuda, S. (contributor); Machida, A. (contributor); Iemura, H. (contributor); Inoue, S. (contributor); Igarashi, A. (contributor); Izuno, K. (contributor); Morichi, S. (contributor); Miki, C. (contributor); Kitada, T. (contributor); Ieda, H. (contributor); Mori, Y. (contributor); Iida, Y. (contributor); Taniguchi, E. (contributor); Nitta, Y. (contributor); Uno, N. (contributor); Imamoto, H. (contributor); Kuroda, K. (contributor); Goto, Y. (contributor); Swaragi, T. (contributor); Nagai, M. (contributor); Asano, M. (contributor); Kunishima, M. (contributor); Kurokawa, T. (contributor); Hosoi, Y. (contributor); Matsui, S. (contributor); Okamura, H. (contributor); Horii, H. (contributor); Nagataki, S. (contributor); Hisada, M. (contributor); Adachi, T. (contributor); Kimura, M. (contributor); Hibino, S. (contributor); Ito, H. (contributor); Fujno, Y. (contributor); Ito, Y. (contributor); Ohga, H. (contributor); Matsui, T. (contributor); Oda, K. (contributor); Matsuo, M. (contributor); Ochiai, H. (contributor); Morikawa, T. (contributor); Umemura, J. (contributor); Fukuoka, S. (contributor); Kanda, T. (contributor); Michioku, K. (contributor); Hibino, T. (contributor); Watanabe, Y. (contributor); Kobayashi, M. (contributor); Takahashi, K. (contributor); Yamanaka, M. (contributor); Fukuda, T. (contributor); Endo, T. (contributor); Inamura, H. (contributor); Ishida, H. (contributor); Higashihara, H. (contributor); Takada, S. (contributor); Okimura, T. (contributor); Lee, T.Y. (contributor); Kawahara, M. (contributor); Kashiyama, K. (contributor); Hirano, H. (contributor); Tyo, T. (contributor); Nakagawa, S. (contributor); Kawata, Y. (contributor); Tanaka, Y. (contributor); Kadonami, S. (contributor); Ichikawa, A. (contributor); Tsuno, H. (contributor); Amano, K. (contributor); Takahara, S. (contributor); Shinozuka, M. (contributor); Kitaura, M. (contributor); Ueno, J. (contributor); Morikawa, H. (contributor); Tanaka, S. (contributor); Ikemoto, T. (contributor); Tamura, J. (contributor); TU Delft","1995","The Japan Society of Civil Engineers (JSCE) received in an extremely serious light the severe damage to various infrastructures, caused by the Hyogoken-Nanbu Earthquake, which occurred in early morning of 17th January. It immediately took the step of organising investigation teams and dispatched them to the disaster area with the aim of elucidating the causes of the damage and thus contributing to the progress of seismic engineering and to the implementation of disaster prevention measures. On the day following the occurrence of the earthquake, the First Study Team, headed by Prof. Jushiro Tamura of Nihon University, chairman of the JSCE Committee on Seismic Engineering, and consisting mainly of researchers in seismic engineering and structural mechanics, was sent to the area for an emergency survey of the damage to the infrastructures. This was followed by the formation and dispatch of the Second Team, headed by me (Prof. Hideo Nakamura of the University of Tokyo), on 22nd January, for a comprehensive survey of the structural and functional damage to and progress of restoration work on railways, roads, port facilities and lifeline utilities. This emergency symposium is being held to provide an opportunity for making brief presentations of the findings of these two study teams. The damage was sa extensive to a variety of structures and sa broadly spread one different areas, the further detailed studies and analyses will be required before any firm conclusions may be drawn on many of the items studied. The views presented here are, in a large number of cases, not consensual description by the Society, but the opinions of individual members of the study teams. However, I am sure that it is our duty to hold an emergency symposium and to make known to the public the findings as quickly as possible. To continue with the surveys on the damage and restoration work, a Third Study Team, headed by Prof. Minoru Matsuo of Nagoya University, was sent to the disaster area on 1st February. The JSCE will take steps to report the findings of this and subsequent study teams at the earliest date possible. In addition, the JSCE will conduct detailed and systematic studies and analyses of the survey results, and present its findings to the public bath in Japan and abroad in the form of a ""Report of the Study on the Great Hanshin Earthquake"" . As members of the JSCE, we intend to devote the maximum amount of effort possible to restoration and reconstruction work in this wake of the earthquake and to the reduction of potential damage in future earthquakes. We entreat all those concerned to favor us with their cooperation and support to these ends.","earthquake; damage report; Great Hanshin Earthquake; JSCE; Hyogkon-Nanbu Earthquake; disaster prevention; structural damage; seismic engineering","en","report","Japan Society of Civil Engineers","","","","","","","","","","","","The Great Hanshin Earthquake","34.603980, 135.031157"
"uuid:7487d9f7-bdb7-449c-b303-1ad78c920927","http://resolver.tudelft.nl/uuid:7487d9f7-bdb7-449c-b303-1ad78c920927","De kust is vrij; pleidooi voor een dynamische omgang met het raakvlak land-zee","Stive, M.J.F.","","1995","","redevoering TBA / Civiele techniek: algemeen / Civil engineering: general TPN / Waterkeringen / Water-retaining structures","nl","lecture notes","Waterloopkundig Laboratorium","","","","","","","","","","","","",""
"uuid:ea8dc765-c8ed-43b2-bc62-8ecac93e809c","http://resolver.tudelft.nl/uuid:ea8dc765-c8ed-43b2-bc62-8ecac93e809c","Performance of a spectral wind-wave model in shallow water","Van Vledder, G.P.; De Ronde, J.G.; Stive, M.J.F.","","1995","","Water waves Mathematical models Forecasting Energy dissipation Coastal zones Coastal engineering Oceanography Wave prediction model Surf breaking Wave energy loss Shallow water Nonlinear triad interactions Water wave energy Abreu formulation 471.4 (Seawat","en","conference paper","American Society of Civel Engineers","","","","","","","","","","","","",""
"uuid:f7f2ff70-f4ee-4ad3-904f-6c6000cb8d6e","http://resolver.tudelft.nl/uuid:f7f2ff70-f4ee-4ad3-904f-6c6000cb8d6e","Hydraulic fracture characterization with dispersion measurements of seismic waves","Groenenboom, J.; Duijndam, A.J.W.; Fokkema, J.T.","","1995","","body waves elastic waves experimental studies geophysical methods hydraulic fracturing laboratory studies P waves rock mechanics seismic methods seismic waves theoretical studies ultrasonic methods wave dispersion 30 Engineering geology 20 Applied geophys","en","conference paper","Society of Exploration Geophysicists","","","","","","","","","","","","",""
"uuid:445489c0-e497-46ae-a65f-1cc48290d260","http://resolver.tudelft.nl/uuid:445489c0-e497-46ae-a65f-1cc48290d260","Behaviour-oriented models of shoreface evolution","Stive, M.J.F.; De Vriend, H.J.; Cowell Peter, J.; Niedoroda, A.W.","","1995","","Coastal zones Geomorphology Mathematical models Mapping Climate change Coastal engineering Sediments Hydrodynamics Shoreface Behaviour oriented models Morphological response Large scale coastal behaviour Topography 471.1 (Oceanography General) 481.1.1 (Ge","en","conference paper","ASCE","","","","","","","","","","","","",""
"uuid:49133860-e12c-4199-a2ab-511c16f999df","http://resolver.tudelft.nl/uuid:49133860-e12c-4199-a2ab-511c16f999df","Geomorphological analysis of a beach and sandbar system","Kung Chen, S.; Stive, M.J.F.; Toms, G.","","1995","","Beaches Computer simulation Computer software Water waves Sediment transport Coastal zones Rivers Ocean currents Wind Sandbar system Geomorphological analysis 407.3 (Coastal Engineering) 723.5 (Computer Applications) 723.1 (Computer Programming) 471.4 (Se","en","conference paper","ASCE; Japan Society of Civil Engineers","","","","","","","","","","","","",""
"uuid:d4dae2c0-28c2-4a92-95cf-cae4136d2820","http://resolver.tudelft.nl/uuid:d4dae2c0-28c2-4a92-95cf-cae4136d2820","Development and validation of a computer assisted design methodology for gas-turbine-based aircraft engines","Eftekhari Shahroudi, K.","Torenbeek, E. (promotor); Van Buijtenen, J.P. (promotor)","1994","","CAD; aircraft engines","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:8e0d8237-343d-4736-af98-1f8f1ec4696d","http://resolver.tudelft.nl/uuid:8e0d8237-343d-4736-af98-1f8f1ec4696d","Hydro-port'94 - Proceedings of the international conference on hydro-technical engineering for port and harbor construction (vol2)","Anonymous, A.","Rijkswaterstaat","1994","Harbour water quality and seawater quality improvement, beach stabilization in the vicinity of a harbour, countermeasures against shoaling due to siltation and sedimentation in the harbour and waterway.","port engineering; water quality; siltation","en","report","Port and Harbour research institute, PARI, Japan","","","","","","","","","","","","KWP-collection",""
"uuid:20693285-928e-47d2-9893-bf014f79f770","http://resolver.tudelft.nl/uuid:20693285-928e-47d2-9893-bf014f79f770","SPINE: Software platform for computer supported co-operative work in heterogenous computer and software environments","Loeve, W.; Baalbergen, E.H.","","1994","In development of High Performance Computing and Networking (HPCN) for simulation applications several targets have to be realized. It is recpiired to maximize not only computational speed but also to maximize applicability in engineering environments. For applications in which HPCN-based simulations are economically and technically necessary tools, it is also essential to minimize the time-to-market of new HPCN tools. HPCN environments are characterized by the application of a variety of computer platforms: vector computers in single emd parallel processor modes, scalar computers with small or large numbers of processors, workstations and a variety of other processing servers for support functions. The computer platforms usually are integrated in a network. The complexity of the heterogenous HPCN computer networks and of the collections of software systems implemented on the networks increases continuously. With increasing economic relevance of HPCN also the need of co-operation of users of HPCN and of developers of HPCN facilities appears to increase. Management of the complexity and co-operation requires tools to realize the above-mentioned targets. In the present paper a software platform (SPINE) is described. The software platform can be installed on arbitrary networks of UNIX computers. The platform can be used for realization of HPCN environments for specific application areas such as computational fluid mechanics or computer aided software development. The platform offers for the specific application the required functions in an integrated way. This integration concerns user interaction, information management, control (concerning specific software as well as concerning the computer network) and processing. The software platform is illustrated with examples from three instantiations of the platform. These are for computational fluid dynamics, computer aided software engineering and computer aided control engineering for non-linear dynamic systems. SPINE appears to be very flexible.","Distributed processing; Computer networks; Data transfer (computers); Data management; Files (tools); Graphical user interface; Information systems; Functional integration; Software engineering; Software tools; Unix (operating system); User requirements","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:81a915ea-2d36-49a4-a2d4-2e3f4e30b83c","http://resolver.tudelft.nl/uuid:81a915ea-2d36-49a4-a2d4-2e3f4e30b83c","Contributions to Workshop Eurobike in Helsinki","Botma, H.","","1994","In this report three subjects relevant for the study of bicycle traffic are presented, giving the state of the art in The Netherlands. They were presented at a workshop of Eurobike, a consortium preparing to carry out practically oriented research about bicycle traffic in European urban areas. The general set-up of the National Travel Survey is described. This survey also includes trips made by bicycle. Some details are given about the size of the survey, the change in method to collect the data in 1985 and the response rate. The modal split as a function of trip distance and the distribution function for bicycle traffic are given as examples of results that can be derived from the survey. In the safety part statistics are given about the general fatality rate of cyclists and other modes of traffic. Two studies to determine criteria for the need for separate cycle paths are described. A study proposal for analysing safety and behaviour in tenns of risk for a mix of fast and slow traffic on an arterial is presented. The third subject is the cycle planning model Quo-Vadis that can be used to determine the best possible cycling network and the best allocation of the budget for bicycle facilities. A short description of the model and its required input is presented. The traffic model part can determine cycle intensities over the period 7 AM to 7 PM on every link of the network and the origins and destinations of the flow. The evaluation part can be used to evaluate an existing network and to assess the effect of measures improving the network. The combination of the model with accident data and the determination of yard-sticks for safety can give indications of how to improve safety.","traffic engineering","en","report","Delft University of Technology, Faculty Civil Engineering and Geosciences","","","","","","","","Civil Engineering and Geosciences","Transport and Planning","","","",""
"uuid:625f2e9e-3d06-46f0-97b8-69aa112bb9d3","http://resolver.tudelft.nl/uuid:625f2e9e-3d06-46f0-97b8-69aa112bb9d3","Pilot performance in automated cockpits: a comparison of moving and nonmoving thrust levers","Folkerts, H.H.; Jorna, P.G.A.M.","","1994","Two different design-philosophies with respect to the Man-Machine Interface of current auto thrust systems were compared in a flight simulator study. With the so-called moving thrust lever concept, the positions of the thrust levers are servo-controlled by the auto thrust system. Hence, the thrust levers provide the pilot with additional information regarding actions taken by the auto thrust system. In contrast, the so-called nonmoving thrust levers are not servo-controlled by the auto thrust system. Pilot performance was investigated when operating these thrust lever configurations. Eight recently licensed civil pilots flew both thrust lever configurations in a moving base flight simulator. The variables used to describe pilot performance were: number of correct detections of problems and failures, detection time and thrust awareness. Questionnaires were used to measure the preference of the pilots for both auto thrust systems. The study demonstrates that moving thrust levers provide effective feedback and assist the pilot in anticipating certain malfunctions and deviations. Pilot detection times are typically shorter and pilots are more certain about their thrust estimates. Pilots confronted with both systems for the first time prefer the moving thrust levers after flying with it. Surprisingly, lack of motion of the moving thrust levers was a strong stimulus for pilots when they expected such a motion to occur. This could indicate that the thrust levers served the pilots especially by providing them prompt feedback on intended actions and served less as a device alerting the pilot to unexpected events.","Engine control; Man machine systems; Pilot performance; Human factors engineering; Levers; Flight simulation; In-flight monitoring; Diagnosis; Throttling; Engine failure","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:d7b2d85c-bbfb-4685-ab30-ce8196fb7d55","http://resolver.tudelft.nl/uuid:d7b2d85c-bbfb-4685-ab30-ce8196fb7d55","SKYLLA: Wave motion in and on coastal structures : implementation and verification of modified boundaries","Petit, H.A.H.; Bosch, P. van den; Gent, M.R.A. van","","1994","","golfmodellen; wave models; verificatie; verification; randwaardeproblemen; boundary value problems; kustwaterbouwkunde; coastal engineering","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:b31215b8-377d-4efb-8e5a-b683b61e5133","http://resolver.tudelft.nl/uuid:b31215b8-377d-4efb-8e5a-b683b61e5133","Marine Exhaust Emissions Research Programme, Progress Report 1","Lloyd's Register of Shipping ","","1994","","marine exhaust; propulsion; environmental engineering","","other","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:c5f2b7dc-a94d-40b9-ac7d-e97f5198137e","http://resolver.tudelft.nl/uuid:c5f2b7dc-a94d-40b9-ac7d-e97f5198137e","Some future directions in computational failure mechanics","De Borst, R.; Carmeliet, J.; Pamin, J.; Sluys, L.J.","","1994","","39 Structural mechanics (Ah); Aero; brittle Materials; computer Techniques; CONFERENCE; Damaging; Deformation; Failure; Finite element method; fracture; fracturing; Heterogeneity; mechanical Engineering; Mechanics; Model; Softening; Stochastic Processes","en","conference paper","Kluwer Academic Publishers","","","","","","","","","","","","",""
"uuid:7f193774-3a03-4b78-9ced-187a3257ffa1","http://resolver.tudelft.nl/uuid:7f193774-3a03-4b78-9ced-187a3257ffa1","Finite element reliability methods using DIANA","Gutierrez, M.A.; Carmeliet, J.; De Borst, R.","","1994","","39 Structural mechanics (Ah); Aero; Beams (supports); computer Techniques; CONFERENCE; Elastic Properties; Finite element method; Model; Reliability; reliability Engineering; Rigid Structures; Stiffness; structural Analysis; structure","en","conference paper","Kluwer Academic Publishers","","","","","","","","","","","","",""
"uuid:8341e6f2-5582-4920-8b7d-9e037f090a96","http://resolver.tudelft.nl/uuid:8341e6f2-5582-4920-8b7d-9e037f090a96","Introduction to bed, bank, shore protection","Schiereck, G.J.","","1993","Loads (flow, waves, ships, porous flow), Erosion (flow, remainder) Load reduction, stability (flow, waves, porous flow), Protections, construction and maintenance, design.","coastal engineering; revetments; shore protection; bed protection","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:ff77dce8-19bc-4612-97b1-3464de96e81a","http://resolver.tudelft.nl/uuid:ff77dce8-19bc-4612-97b1-3464de96e81a","River engineering","De Vries, M.","","1993","One dimension models - basic eauations, analytical models, numberical models. One dimensional models -suspended load, roughness and resistance of river beds. Solving river problems - tools, flood mitigation, bank protection.","river engineering; rivers","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:3cf1453e-4e19-468e-b94e-1d9422e1e70b","http://resolver.tudelft.nl/uuid:3cf1453e-4e19-468e-b94e-1d9422e1e70b","Shore nourishment and the active zone: A time scale dependent view","Stive, M.J.F.; De Vriend, H.J.; Nicholls Robert, J.; Capobianco, M.","","1993","","evolution; Shore protection Coastal zones Coastal engineering Sediment transport Water wave effects Beaches shore nourishment Sand shifting Shoal zone Cross shore spreading Closure depth 407.3 (Coastal Engineering) 631.1 (Fluid Flow General) 471.4 (Seawater, Tides a","en","conference paper","","","","","","","","","","","","","",""
"uuid:a45c14e5-05c0-48b3-8fed-2bea3740e69c","http://resolver.tudelft.nl/uuid:a45c14e5-05c0-48b3-8fed-2bea3740e69c","Approaches to long-term modelling of coastal morphology: A review","De Vriend, H.J.; Capobianco, M.; Chesher, T.; De Swart, H.E.; Latteux, B.; Stive, M.J.F.","","1993","","Coastal zones Coastal engineering Beaches Shore protection Hydrodynamics Water waves Morphology Hydraulic models Simulation Coastal area modeling Coastal evolution 407.3 (Coastal Engineering) 471.4 (Seawater, Tides and Waves) 631.2 (Hydrodynamics)","en","journal article","Elsevier","","","","","","","","","","","","",""
"uuid:efbf1131-826c-4f9e-a582-eca6872a7523","http://resolver.tudelft.nl/uuid:efbf1131-826c-4f9e-a582-eca6872a7523","Global vulnerability assessment: Vulnerability of coastal areas to sea-level rise","Hoozemans, F.M.J.; Stive, M.J.F.; Bijlsma, L.","","1993","","Coastal engineering Sea level Coastal zones Global vulnerability assessment Sea level rise 407.3 (Coastal Engineering) 471.4 (Seawater, Tides and Waves)","en","conference paper","American Shore and Beach Preservation Association; ASCE; Coastal Zone Foundation; Guenoc Winery; Louisiana Department of Natural Resources; et al","","","","","","","","","","","","",""
"uuid:07aa6041-f148-4e39-b40d-686352d0c253","http://resolver.tudelft.nl/uuid:07aa6041-f148-4e39-b40d-686352d0c253","ECMOR III: 3rd European Conference on the Mathematics of Oil Recovery, 17-19 June 1992","Christie, M.A.; Da Silva, F.V.; Farmer, C.L.; Guillon, O.; Heinemann, Z.E.; Lemonnier, P.; Regtien, J.M.M.; Van Spronsen, E.","","1992","","petroleum exploration; petroleum production; reservoir engineering; production technology","en","book","Delft University Press","","","","","","","","Delft University of Technology","","","","",""
"uuid:b09dd778-3daf-4ab0-ba9e-2dec697f88eb","http://resolver.tudelft.nl/uuid:b09dd778-3daf-4ab0-ba9e-2dec697f88eb","Engineering Approaches to Cross-Shore Sediment Transport Processes","Kraus, N.C.","TU Delft","1992","In this chapter we consider beach profile and cross-shore sediment transport processes commonly encountered in coastal engineering applications. Main emphasis is on beach profile change produced by direct wave action, and our assumption will be that longshore transport processes are constant along the profile. Present engineering knowledge of cross-shore transport processes draws heavily on conceptual models that simplify the target problem to a manageable state that is hoped represents the essence of the phenomenon. The engineer should be aware of both the strengths and limitations of these simplifying techniques and models used. Such engineering approaches will be described here. Example calculations for selected topics are presented to show the applications of the material presented here. At present, approaches that isolate cross-shore and longshore processes are highly fruitful and appropriate owing to our limited understanding of nearshore hydrodynamic sand sediment transport. Ultimately, the nearshore must be treated through a fully three-dimensional model. The topics discussed: - Equilibrium properties of beach profiles - Equilibrium beach profile (x^(2/3)) - Equilibrium profile with sloping beach face - Applications of equilibrium beach profiles - Depth of closure - Erosion and accretion predictors","engineering approach; cross-shore; sediment transport","en","report","ICCE 1992 local organising committee","","","","","","","","","","","","ICCE 1992",""
"uuid:5233ff2e-3bb3-4e28-8a56-dde6b532420d","http://resolver.tudelft.nl/uuid:5233ff2e-3bb3-4e28-8a56-dde6b532420d","Design and Reliability of Coastal Structures","Tomasicchio, U.","TU Delft","1992","Contributions of a short course connected to the 23rd international conference on coastal engineering (ICCE 1992) in Venice, Scuola di S. Gioovanni Evangelista - document contains links to full text contributions","coastal engineering; coastal structures","en","report","ICCE 1992 local organising committee","","","","","","","","","","","","",""
"uuid:f6346bd5-ba34-452d-8a94-98b285368701","http://resolver.tudelft.nl/uuid:f6346bd5-ba34-452d-8a94-98b285368701","Geotextile Design & Construction Guidelines: Participant Notebook","Christopher, B.R.; Holtz, R.D.","Rijkswaterstaat","1992","These guidelines have been condensed from the FHWA Geotextile Engineering Manual (1985) for use as an implementationdocument for project managers and highway designers. It will also be useful as a design reference guide for pavement and geotechnical specialists. The guidelines when used in conjunction with the FHWA Geotextile Engineering Manual will enable the highway engineer to properly design, select, test, specify, and construct with geotextiles and related products such as geogrids and geocomposite drainage materials. Af ter a general introductory chapter, application chapters are presented on drainage, erosion control (permanent and temporary), roadways, pavement overlays, and reinforced embankments, slopes, and retaining walls and abutments. Each chapter presents step-by-step procedures for design, selection, and installation of geotextiles for these applications. For additional information, references are provided to supplement those given in the FHWA Geotextile Engineering Manual.","geotextiles; geogrids; geocomposites; geotechnical engineering; roadway design; filters; drains; erosion control; stabilization; reinforcement","en","report","U.S.Department of Transportation Federal Highway Administration","","","","","","","","","","","","KWP-collection",""
"uuid:66fc48c4-57ea-46ce-ba4e-8a5f09ee2543","http://resolver.tudelft.nl/uuid:66fc48c4-57ea-46ce-ba4e-8a5f09ee2543","An efficient algorithm for the computation of Galerkin coarse grid approximation for the incompressible Navier-Stokes equations","Zeng, S.; Wesseling, P.","","1992","","BBA / Wiskunde (algemeen) / Mathematics (general) CDA / Numerieke wiskunde / Numerical mathematics CXA / Programmatuurontwikkeling (algemeen) / Software engineering (general); navier-stokes equations","en","report","Delft University of Technology","","","","","","","","","","","","",""
"uuid:78f5d3ac-ab6c-4d06-8574-8af46cb04de2","http://resolver.tudelft.nl/uuid:78f5d3ac-ab6c-4d06-8574-8af46cb04de2","Wasmiddelen voor gasturbines vallen vies tegen","Kolkman, H.J.","","1991","Deposits are regularly removed from compressor blades and vanes of installed jet engines and gas turbines by compressor washing. Hereby a compressor cleaner is sprayed into the compressor while operating at reduced or normal r.p.m. Recently developed compressor cleaners are claimed to be ecologically sound. In addition, many new compressor cleaners contain a corrosion inhibitor. The cleaning efficiency of eight (old and new) compressor cleaners was determined by means of simulated compressor washing of compressor blades that had become foul in service. For the situation simulated, the cleaning efficiency of new, ecologically sound cleaners turned out to be poor as compared with old compressor cleaners.","jet engines; gas turbines; washing; aircraft maintenance; cleaners; corrosion prevention; inhibitors; compressor blades","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:c335adbe-9fd6-4032-9c2d-8d6c434c747f","http://resolver.tudelft.nl/uuid:c335adbe-9fd6-4032-9c2d-8d6c434c747f","DEFMEF predesign document","de Jong, S.","","1991","The predesign document of DEFMEF presents the decisive requirements for the DEFMEF language and the associated DEFMEF translator. It also shows a basic technical design, which fulfills the requirements. DEFMEF as a software design language has been designed so, that it is possible to describe both a technical design and a detailed design with it. The DEFMEF translator generates input for both MEBAS and EFFORD, two CASE-tools that have also been developed at NLR. The thus obtained set of CASE-tools, DEFMEF, MEBAS and EFFORD, fulfills a large part of the software engineering process. At the same time, DEFMEF benefits the consistency of the information, used by all three tools.","software engineering; computer systems design; software tools; computer aided design; functional design specifications; translators; subroutines; fortran; high level languages","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:6f7b87ef-68a7-4322-bc4d-671d21bea321","http://resolver.tudelft.nl/uuid:6f7b87ef-68a7-4322-bc4d-671d21bea321","Sea-level rise and shore nourishment. A discussion","Stive, M.J.F.; Nicholls Robert, J.; De Vriend, H.J.","","1991","","evolution; Shore protection OCEANOGRAPHY Sea Level Changes COASTAL ENGINEERING Mathematical Models COASTAL ZONES Morphology Shore nourishment conceptual models 407 (Maritime and Port Structures, Rivers and other Waterways) 471 (Marine Science and Oceanography)","en","journal article","","","","","","","","","","","","","",""
"uuid:844eedba-5186-4bd4-a7cc-477f54820934","http://resolver.tudelft.nl/uuid:844eedba-5186-4bd4-a7cc-477f54820934","De faculteit en haar computer, leefden ze lang en was iemand gelukkig?","Loeve, W.","","1990","For Support and Research and of Education in Universities computers are required. In the paper advantages and disadvantages of centralized and decentralized automation and support groups are discussed.","cooperation; teams; software engineering; project management; university program; universities","nl","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:8cb5d1cc-ba2e-4f30-9233-5cfddca4ba1e","http://resolver.tudelft.nl/uuid:8cb5d1cc-ba2e-4f30-9233-5cfddca4ba1e","De plaats van de wiskundige bij de ontwikkeling van digitale simulatie-systemen voor toepassingen uit de ""Computational physics""","van der Wees, A.J.; van den Berg, J.I.","","1990","NLR mainly performs applied scientific research for use in the aerospace industry. In many cases the product has the form of an information system for the design, production and usage of aerospace vehicles. Within this context, the mathematician contributes, in cooperation with specialists from other disciplines such as aerodynamics, structures, aviation and aerospace, to the development of these systems. The mathematician is responsible for the numerical aspects of the system. An important aspect is the validation of software on its usefulness in applications. Paper presented at the Mathematical Congress at Nijmegen University, April 20, 1990.","computerized simulation; computer systems program; software engineering; scientists; computational fluid dynamics; numerical analysis; mathematical models; software tools; error analysis; systems management; application programs (computers); reuse","nl","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:8527d4f3-8b9e-4050-92ac-b1b126a18d2d","http://resolver.tudelft.nl/uuid:8527d4f3-8b9e-4050-92ac-b1b126a18d2d","Sand transport on the shoreface of the Holland coast. The Dutch coast. Paper No. 5","Roelvink, J.A.; Stive, M.J.F.","","1990","","Coastal zones FLOW OF WATER Sediment Transport SAND AND GRAVEL Erosion COASTAL ENGINEERING WATER WAVES TIDES Sand transport tidal flow velocity 471 (Marine Science and Oceanography) 631 (Fluid Flow) 483 (Soil Mechanics and Foundations)","en","conference paper","","","","","","","","","","","","","",""
"uuid:ac1adaff-fa2c-49a7-ae39-109cbcd11868","http://resolver.tudelft.nl/uuid:ac1adaff-fa2c-49a7-ae39-109cbcd11868","Large-Scale Coastal Evolution Concept","Stive, M.J.F.; Roelvink, D.A.; De Vriend, H.J.","","1990","","53 Waterways (CE); CIVIL; Coastal Engineering; Coastal Morphology; Coastal Processes; Estuaries; evolution; netherlands; Sand Transport; Sea Level","en","conference paper","American Society of Civil Engineers","","","","","","","","","","","","",""
"uuid:0fa1f106-4e36-4309-a690-79a835e2601e","http://resolver.tudelft.nl/uuid:0fa1f106-4e36-4309-a690-79a835e2601e","Analysis of concrete structures under thermal loading","De Borst, R.; Peeters, P.P.J.M.","","1989","","Accuracy; Algorithm; C7440 Civil and mechanical engineering computing; Civil; Concrete; concrete structures; Cracking; Creep; generalised mid point rule; integration; linearisation moduli; Loading; material behaviour; material properties; mechanical; Model; Plain concrete; Plain-concrete; Reinforced concrete; reinforced concrete slab; Reinforced-concrete; STEEL; structural engineering computing; structure; Structures; temperature dependent material properties; thermal dilatation; thermal loading; time integrator; transient creep","en","journal article","","","","","","","","","","","","","",""
"uuid:d26eccf3-bf97-4340-bb1d-c099c91d456d","http://resolver.tudelft.nl/uuid:d26eccf3-bf97-4340-bb1d-c099c91d456d","Bounds and constructions for binary block codes correcting asymmetric or unidirectional errors","Weber, J.H.","Boekee, D.E. (promotor); De Vroedt, C. (promotor)","1989","","Error-correcting codes; software engineering (general)","en","doctoral thesis","","","","","","","","","","","","","",""
"uuid:5adb0e01-c391-47a4-8449-6ced10666f43","http://resolver.tudelft.nl/uuid:5adb0e01-c391-47a4-8449-6ced10666f43","Praktijkgericht onderzoek milieuvriendelijke oevers: Erosie door open taludbekledingen","Wal, M. van der","","1989","","taluds; slopes; oeverbescherming; bank protection; oevererosie; bank erosion; milieutechniek; environment engineering","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:a10d5639-817d-4c96-bb6a-f88fcd2f850a","http://resolver.tudelft.nl/uuid:a10d5639-817d-4c96-bb6a-f88fcd2f850a","DFMS: Architecture and implementation of a distributed control system for FMS","Bakker, J.J.A.","Reijers, L.N. (promotor)","1989","","flexible manufacturing systems; mechanical engineering design: computer applications","en","doctoral thesis","","","","","","","","","","","","","",""
"uuid:e69767f9-328f-4183-b40d-804fcd587537","http://resolver.tudelft.nl/uuid:e69767f9-328f-4183-b40d-804fcd587537","The use of MEBAS in creating a simulation environment for compression and encryption","Kordes, F.L.G.; Schuurman, J.J.","","1989","In order to get a better sight on the performance of compression and encryption algorithms under various conditions a simulation environment is needed. Within this simulation environment It must be possible to investigate the influence of code tables, channel characteristics and frame formats on the performance of the algorithms. In this report the use of MEBAS in creating this simulation environment is studied.","information systems; systems engineering; software tools; data management; computerized simulation; subroutine libraries (computers); frames (data processing); source programs; data compression","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:3809dc56-bd6b-4dcf-848e-f9ccb2732191","http://resolver.tudelft.nl/uuid:3809dc56-bd6b-4dcf-848e-f9ccb2732191","Processing of advanced ceramics which have potential for use in gas turbine aero engines","Maccagno, T.M.","","1989","SiaN4 and SiC based advanced ceramics that have been produced by hot isostatic pressing (HIP'ing) have good potential to be used as hot section components in gas turbine aero engines. This report provides background for an NAE-SML investigation of this potential. The report begins with a general overview of the many fabrication methods that have been used to produce both monolithic ceramics and SiC whisker reinforced composite ceramics. This is followed by a comprehensive survey of past efforts to produce SiaN4 and SiC based ceramics by HIP 'ing. It is apparent that many of these efforts have involved HIP'ing of material that has already been densified by sintering, but such an approach does not really allow the fulI benefits of HIP processing to be realized. On the other hand, HIP'ing of SiaN4 based composite produced by reaction bonding may result in ceramic material of superior quality. It also appears that manY previous efforts have resorted to incorporating densifying aids into the starting material, even though high temperature properties may suffer as aresult. It is suggested th at HIP'ing of vacuum encapsulated SiaN 4 or SiC particulate which contains SiC whiskers for reinforcement, but which does not contain densifying aids, may be a method of producing ceramic material of sufficient quality to be considered for use in gas turbine engines.","Gas turbine Engines - ceramics; Ceramics - Processing; Hot pressing","en","report","National Research Council Canada","","","","","","Campus only","","","","","","",""
"uuid:b6eda6ca-cab6-4ffb-9669-66233613856f","http://resolver.tudelft.nl/uuid:b6eda6ca-cab6-4ffb-9669-66233613856f","Coastal Engineering","Van der Velden, E.T.J.M.","","1989","Introduction, waves, sediment transport, littoral transport, lonshore sediment transport, onshore-offshore sediment transport, coastal changes, dune erosion and storm surges, sedimentation in channels and trenches, coastal engineering in practice.","coastal engineering; coastal morphology; sediment transport","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:f1613c12-6b88-408f-abc4-341b9d7dcca5","http://resolver.tudelft.nl/uuid:f1613c12-6b88-408f-abc4-341b9d7dcca5","GELUIDHINDER IN STEDLIJK GEBIED: WAAR, IN WELKE MATE, BIJ WIE?; NOISE HINDRANCE IN URBAN AREA: WHERE, IN WHICH WAY, AND BY WHO?","Van Der Zande, M.J.M.; Bovy, P.H.L.","","1989","","Conference 8525 traffic 0655 sound 6748 sound level 6747 pollution 5227 method 9102 forecast 0122 evaluation assessment 9020 environment 9018 planning 0133 traffic engineering 0657 prevention 1670 program computer 8646 urban area 0313 netherlands 8078 Veh","nl","report","","","","","","","","","","","","","",""
"uuid:2726677a-6971-4b5d-81e3-bc730a294678","http://resolver.tudelft.nl/uuid:2726677a-6971-4b5d-81e3-bc730a294678","Evaluation of the applicability of Helmholtz resonators for low frequency acoustic liners","van der Wal, H.H.M.","","1988","A literature study has been carried out on the acoustic behaviour of those Helmholtz resonator type liners which are most promising for low frequency sound absorption in aero-engine applications. The equations for the acoustic impedance of various types of Helmholtz resonators have been analyzed as well as the conditions for the validity of these equations. An experimental program is defined for a further analysis of various types of resonators.","Helmholtz resonators; linings; turbofan engines; acoustic attenuation; low frequencies; acoustic impedance; absortivity","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:67e5692c-0905-4ddd-8487-37fdda9af6b4","http://resolver.tudelft.nl/uuid:67e5692c-0905-4ddd-8487-37fdda9af6b4","Rock slopes and gravel beaches under wave attack","van der Meer, J.W.","Bijker, E.W. (promotor)","1988","Abstract not available","rubble mound breakwaters; rubble mound revetments; rock beaches; gravel beaches; coastal processes; coastal engineering; water-retaining structures","en","doctoral thesis","Delft Hydraulics Laboratory","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:8128e88f-b57d-46f7-84ac-0249e1a0537e","http://resolver.tudelft.nl/uuid:8128e88f-b57d-46f7-84ac-0249e1a0537e","Bifurcations in finite element models with a non-associated flow law","De Borst, R.","","1988","","63 Mathematics and Computation (CE); Bifurcations; C ca16.4 Mechanics and mechanical engineering; Civil; Civil engineering (Ci); Cohesion; Diffusion; Eigenvalues; Empirical Analysis; Finite element method; I 8400 civil engineering; Loading; Localization; Mathematical Models; Mechanics; Model; Position (location); Positioning; Shear; Slip Bands; Slope; Soil Mechanics; Stiffness; Stiffness Matrix; Wavelengths","en","journal article","","","","","","","","","","","","","",""
"uuid:fb90981f-5a61-479f-9b09-ab59cac1612d","http://resolver.tudelft.nl/uuid:fb90981f-5a61-479f-9b09-ab59cac1612d","The closure of tidal basins: Closing of estuaries: tidal inlets and dike breaches","Huis in 't Veld, J.C.","","1987","","coastal engineering; water-retaining structures","en","book","Delft University Press","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:235d6c8c-d459-4ef6-ba96-79536af2abe1","http://resolver.tudelft.nl/uuid:235d6c8c-d459-4ef6-ba96-79536af2abe1","Handleiding voor het gebruik van NEXT 1.2 - User manual NEXT 1.2 - NLR engineering X-pert system Toolkit","Kat, P.J.; Donker, J.C.","","1987","NEXT 1.2 is an expert system shell developed at NLR. NEXT has a knowledge representation mechanism based on a combination of context tree and production rules. The inference mechanism is based on a combination of backward and forward reasoning. NEXT 1.2 is available on a CYBER 180/855 under NOS and on a VAX under VMS. Supply of other implementations can be negotiated. This user manual is written to support the knowledge engineers building knowledge based systems with NEXT.","Systems engineering; Expert system; Inference; Software Tools; CDC Computer; VAX computers; User manuals (computer programs)","nl","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:feb02134-39aa-4093-8a28-b8838a621dbe","http://resolver.tudelft.nl/uuid:feb02134-39aa-4093-8a28-b8838a621dbe","Rinsing water analysis of helicopter jet engine compressors","Kolkman, H.J.","","1987","","Protective Coatings; Chemical analysis; Corrosion prevention; Chemical attack; Sea water; BO-105 Helicopters; Helicopter engines; Compressor rotors; Flushing","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:785ceed0-a828-41f3-929a-42e538e9d7fc","http://resolver.tudelft.nl/uuid:785ceed0-a828-41f3-929a-42e538e9d7fc","Voorontwerp methodenbestandssysteem - Preliminary design method base system","van Hulzen, J.J.P.","","1987","The informatics policy at NLR is focussed on providing an infrastructure for the development of information systems. A new component in the infrastructure is the method base system, designed to support the management and use of algorithm implemented in programs. The preliminary design analyses the functions of the method base system and elaborates on issues for the technical concept. It is found that this concept can be fit into the overall concept, defined in the plan for the informatics policy at NLR. Finally, plans for implementing and realising the method base system at NLR are defined in this document.","Software tools; Data management; User requirements; Computer systems design; Subroutine libraries (computers); Merging routines; Interfaces; Interactive control; Application programs (computers); Software engineering; Management information systems; Signal distortion","nl","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:f2b2db60-fe87-4746-ab07-ccad55fc5841","http://resolver.tudelft.nl/uuid:f2b2db60-fe87-4746-ab07-ccad55fc5841","The acoustics of a lined duct with flow","Rienstra, S.W.","","1987","The present report describes a theory to calculate the sound propagation (including attenuation, reflection, radiation) through a three-sectioned cylindrical flow duct, modelling an aero-engine inlet. The flow is uniform apart from a thin boundary layer; two of the three sections are hardwalled, with an impedance-walled section in between. The modal amplitudes of the sound field in the duct are determined by an iterative technique allowing the modal expansions to include as many terms as required. The modal eigenvalues are found using a classification based on a distinction between acoustic modes and surface waves. Numerically, the main results (in the sense of practical applications) are contour plots of constant attenuation, in the complex impedance plane. One of the most striking observations is a dramatic effect of lining (via the occurrence of surface waves) on a sound field that is cut-off in a hard-walled duct. In addition to the above problem with a lining of constant impedance, the problem of a (necessarily variable) non-reflective impedance is briefly considered. This problem is mainly relevant to an (acoustic) wind tunnel. It is shown that, for a given free field of the source, the solution, describing this impedance distribution, can be given analytically, in closed form.","Acoustic ducts; Aeroacoustics; Matching; Engine inlets; Acoustic impedance; Sound fields; Mathematical models; Propagation modes; Lining","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:e8dddd02-8cfa-48f0-add8-53df414c9538","http://resolver.tudelft.nl/uuid:e8dddd02-8cfa-48f0-add8-53df414c9538","Computation of post-bifurcation and post-failure behavior of strain-softening solids","De Borst, R.","","1987","","63 Mathematics and Computation (CE); Bifurcations; C ca16.4 Mechanics and mechanical engineering; Civil; Civil engineering (Ci); Computation; Concrete; Failure; Failure Modes; I 8400 civil engineering; Mathematical Models; Model; Reinforced concrete; Reinforced-concrete; Reinforcing Steels; Solids; Strain; Strain softening; Strain-softening; structural Analysis","en","journal article","","","","","","","","","","","","","",""
"uuid:4053a7d6-cb1e-4d3f-acfd-2ba9df4663f7","http://resolver.tudelft.nl/uuid:4053a7d6-cb1e-4d3f-acfd-2ba9df4663f7","Integration of plasticity equations for singular yield functions","De Borst, R.","","1987","","A0260 Numerical approximation and analysis; A0340 Classical mechanics of continuous media: general mathematical aspects; A4630J Viscoelasticity, plasticity, viscoplasticity, creep, and stress relaxation; Algorithm; C4160 Numerical integration and differentiation; C7440 Civil and mechanical engineering computing; Criteria; Equation; explicit expression; integration; Koiter's requirements; mechanical; mechanical Engineering; Mohr Coulomb; Plastic Flow; Plasticity; plasticity equations; singular yield functions; Stress strain; stress strain law; stress strain laws; stress strain relations; Stresses; Tresca yield criteria; yield function; yield surface","en","journal article","","","","","","","","","","","","","",""
"uuid:11802c08-0675-46de-baf9-9b0c3da0facf","http://resolver.tudelft.nl/uuid:11802c08-0675-46de-baf9-9b0c3da0facf","Gedrags- / prestatiekarakteristieken van informatievoorziening - Performance characteristics for information supply","van Hulzen, J.J.P.; de Moel, R.P.","","1986","Technical/industrial automation focusses on the primary business processes, such as design and fabrication of products. In view of the importance extensive studies are required to demonstrate the feasibility and to motivates various choices. Moreover stringent requirements for the information supply will be defined. The National Aerospace Laboratory NLR has gained vast experience in both aspects. In this article the second aspect will be elaborated, focussing on the performance characteristics in the context of all other requirements. Experiences up to now with the resulting scheme for requirements are positive.","Software engineering; Systems analysis; Functional design specifications; Software tools; User requirements; On-line systems; Computer systems performance; Response time (computers); Reliability; Security","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:72b95320-32a4-4b37-8e57-c549af6752ad","http://resolver.tudelft.nl/uuid:72b95320-32a4-4b37-8e57-c549af6752ad","Flight simulator experiments concerning take-off visibility minima","van Gool, M.F.C.","","1986","The Working Group on All-Weather Operations of the European Civil Aviation Conference (ECAC) has initiated a study concerning the factors influencing the minium required visibility at take-off. In two special checkout sessions on the KLM Boeing 747 flight simulator, the experimental conditions have been defined for an investigation directed at the minimum required visual reference to control the aircraft after a failure of the most critical engine at an inconvenient moment during the take-off run. An investigation has been carried out involving a large number of KLM Boeing 747 crews, in which a total of 159 aborted take-offs have been performed in low visibility. This report presents the results of pilot comments and ratings as well as measured pilot-aircraft performance data for these take-offs. It is concluded that aborted take-offs can be performed safely in night conditions on runways with 15 or 30 m centreline light spacing with an RVR of as low as 150 m, provided the pilot-flying keeps looking outside and the pilot not-flying gives speed calls.","Low visibility; Pilot performance; Flight simulation; Boeing 747 aircraft; Takeoff; Runway lights; Engine failure; Ratings","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:6717ac76-de71-448c-b98d-2cf2a17067ff","http://resolver.tudelft.nl/uuid:6717ac76-de71-448c-b98d-2cf2a17067ff","Coastal engineering: Vol II. Harbor and beach problems","Massie, W.W.","","1986","Ship motions, channel depth, channel width, ship maneuvering models, maneuverability improvement, total channel optimization, coastal sand transport, radiation stress, wave set-up, radiation stress gradient, tidal forces, turbulent forces, bottom friction forces, longshore current computations, early coastal transport formula, sand transport mechanisms, model coastal transport formula, coastal dynamics with single line theory, sand transport along a beach profile, coastal changes with multiple line theory, dune coasts, shore protection works, channel sedimentation.","coastal engineering","en","report","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:8acecfcf-5a97-4484-8379-3062cd49f78f","http://resolver.tudelft.nl/uuid:8acecfcf-5a97-4484-8379-3062cd49f78f","Coastal Engineering: Glossary and conversion factors","Massie, W.W.","","1986","Overview of coastal engineerig terms.","coastal engineering","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4b33f18d-a18b-4a68-b2f9-57a58e69ff52","http://resolver.tudelft.nl/uuid:4b33f18d-a18b-4a68-b2f9-57a58e69ff52","Coastal Engineering. vol III: Breakwater design","Massie, W.W.","","1986","General considerations, types of breakwaters, rubble mound breakwaters, wave run-up and overtopping, construction materials, armor computations, te core, filter and toe constructions, rubble mound breakwater construction, optimum design, example, monolithic breakwater, construction materials, wave foreces on vertical walls, monolithic breakwater foundations, influence of breakwater on waves, construction of monolitic breakwaters, optimum design, Rotterdam-Europoort entrance design.","coastal engineering; breakwaters; caisson breakwaters; armour units","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:e3132a3a-b074-4140-ad52-7652bccb184e","http://resolver.tudelft.nl/uuid:e3132a3a-b074-4140-ad52-7652bccb184e","Control loops with human operators in space operations: part II: robotics operations and manual control experiment","van Swieten, A.C.M.; Kampen, S.","","1985","In the study ""Control loops with human operators"" this volume is concerned with the robot arm case. Servicing of satellites and assembly of space structures require robotic operations. These operations are controlled from the ground by human operators. Five operational modes for the combined space- and ground segment are defined: - high level manipulation, - manual augmented, - preprogrammed, - single joint (emergency mode), - direct drive (emergency mode). Three of these modes require direct manual control. The main difficulty in the manual modes is the presence of time delay in the control loop and the way the operator can cope with it. In order to get an impression, human operator performance was assessed for the direct drive mode, in which the system provides the least support. A simple model for this mode showed essentially non-linear actuator behaviour, which made results from the literature not applicable. Therefore, some explorative experiments were done. These experiments showed, that the test subject (operator) could control the system, but a lot of overshooting responses were observed. Possibly, these overshoots can be eliminated by different instructions to the operator, who was instructed in the experiments to be as fast as possible.","human engineering; man machine systems; human performance; research facilities; manipulators; teleoperators; remote control; time lag; control sticks; manual control; space stations; display devices","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:e8407a13-ac39-4758-ad59-3624911aaba3","http://resolver.tudelft.nl/uuid:e8407a13-ac39-4758-ad59-3624911aaba3","Bituminous materials in hydraulic engineering","Van Dijk, W.; Agema, J.F.","TU Delft","1985","","Asfaltbekleding; Bituminous Mixes; Hydraulic Engineering","en","report","Eurobitume","","","","","","","","","","","","Eurobitume",""
"uuid:979a16dd-d7d2-4ba8-9dde-91bbe6bd4f8d","http://resolver.tudelft.nl/uuid:979a16dd-d7d2-4ba8-9dde-91bbe6bd4f8d","Control loops with human operators in space operations: part IV: research requirements for human-in-the-loop space teleoperator development","Milgram, P.","","1985","This report presents a discussion of short-term human engineering research requirements for developing rendezvous and docking and space telemanipulation capabilities. A catalogue of research topics related to human-in-the-loop teleoperation performance is given. This is followed by an overview of available resources for model analytical investigation of these research topics and an overview of resources for the establishment of an initial human performance research laboratory for carrying out such investigations and for testing proposed design concepts.","human factors engineering; human performance; space station; man machine systems; spacecraft docking; space rendezvous; robotics; manipulations; teleoperators; research facilities; functional design specifications","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:c4a88773-26af-43ab-847d-2ea8ea308716","http://resolver.tudelft.nl/uuid:c4a88773-26af-43ab-847d-2ea8ea308716","Control loops with human operators in space operations: part I: human engineering analysis, synthesis and evaluation techniques","Milgram, P.; van de Graaff, R.C.; Wewerinke, P.H.","","1985","This report is a tutorial overview for the European Space Agency (ESA) of human engineering approaches and methodologies which are applicable for analysis of performance of human-machine systems, with specific emphasis on space teleoperator applications. Motivated by the presumed active role of the human operator in future space teleoperation missions, the application of human engineering within the various stages of system development is discussed, with emphasis placed on the impact on the development cycle of being able to analyse various aspects of human-in-the-loop system performance. Two approaches to human performance analysis are identified: experimental and theoretical, and both fundamental and practical aspects of each approach are reviewed in detail, with examples. The report concludes with a proposed modelling approach for the analysis of a specific class of supervisory space teleoperator missions, accompanied by a discussion of considerations related to human-computer task allocation for such missions.","human factors engineering; man machine system; research facilities; human performance teleoperation; mathematical models; workloads (psychophysiology); supervisory control; task complexity 1; decision making 1; space crews 1; space stations","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:e7a6c7fe-da4d-4d24-b19c-ab7d21448f67","http://resolver.tudelft.nl/uuid:e7a6c7fe-da4d-4d24-b19c-ab7d21448f67","Control loops with human operators in space operations: part V: executive summary","Milgram, P.","","1985","This volume comprises the executive summary of the final report of the study on Control Loops with Human Operators in Space Operations, performed for the European Space Agency (ESA). It summarises the following four volumes: Part I : Human Engineering Analysis, Synthesis and Evaluation Techniques (NLR) Part II : Robotics Operations and Manual Control Experiment (Fokker) Part III: Rendezvous and Docking Operations and Model Analysis of Performance with Human-in-the-loop (NLR) Part IV : Research Requirements for Human-in-the-loop Space Teleoperator Development (NLR)","space rendezvous; human factors engineering; spacecraft docking; teleoperators; manipulators; man machine systems; human performance; manual control; robotics; supervisory control; decision making; optimal control; research facilities","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:077194d4-1d33-4bab-9a50-6cc411225efc","http://resolver.tudelft.nl/uuid:077194d4-1d33-4bab-9a50-6cc411225efc","Verification of obstacle accountability areas using a simple mathematical model: part I: description of general model and application for a specific case","Moek, G.","","1985","A probabilistic model is described for the lateral displacement of an aircraft after the occurrence of an engine failure during take-off. With the model, a lateral boundary is calculated, for any point of time after the engine failure, such that the probability of being within the (two sided) lateral boundary meets a specified value. Various probability distributions for the three model parameters are considered. The model is elaborated for one specific set of probability distributions. The resulting lateral boundaries are compared with the present ICAO annex 6 obstacle accountability area.","engine failures; flight paths; take off; mathematical models; probability density functions; obstacles; probability distribution functions; climbing flight","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:5e16f146-df95-4473-8476-b81e7cd8f781","http://resolver.tudelft.nl/uuid:5e16f146-df95-4473-8476-b81e7cd8f781","Simulation and optimization techniques in computer aided design","van den Dam, R.F.","","1985","The use of numerical simulation and optimization techniques is rapidly expanding in all fields of engineering design. The place and the potential of these techniques in the design process, as well as their use by the designer, are discussed. The principles underlying these techniques are outlined and an overall view is given of the various methods that can be applied. Examples of applications are presented to illustrate their usefulness in design processes. Attention is paid to the integration of these techniques into structured systems for computer aided design, and to the implementation of these systems in the infra-structure of the organisation.","mathematical models; optimization; computer aided design; computerized simulation; mathematical programming; nonlinear optimization; aircraft design; software tools; specifications; systems engineering; structural design; drag reduction; weight reduction","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:4969619e-c2de-4c5e-a3d1-3a36f3980d04","http://resolver.tudelft.nl/uuid:4969619e-c2de-4c5e-a3d1-3a36f3980d04","Condition monitoring, trend analysis and maintenance prediction","de Jong, W.; de Vries, R.J.","","1985","","engine diagnostics; monitoring; maintenance","","report","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:4e95ddfd-6ee8-4fe6-8eed-0b3b07c0c757","http://resolver.tudelft.nl/uuid:4e95ddfd-6ee8-4fe6-8eed-0b3b07c0c757","Engineering potamology","De Vries, M.","","1985","Lecture notes on river engineering and river morphology.","river morphology; river engineering","en","lecture notes","TU Delft, Department Hydraulic Engineering and IHE Delft","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4cfcf45a-3b64-4b51-86ad-40fbc4ff1b50","http://resolver.tudelft.nl/uuid:4cfcf45a-3b64-4b51-86ad-40fbc4ff1b50","The use of asphalt in hydraulic engineering","Anonymus, N.N.","Van de Velde, P.A. (contributor); Rijkswaterstaat","1985","Manual for the design and execution of bituminous layers in hydraulic structures, like on dike revetments, bed protections, etc. Includes asphaltic concrete, open stone asphalt (fixstone), sand asphalt, mastic, etc. Also guidance is given for compostion and properties of asphalt mixes.","asphalt; dikes; hydraulic engineering; cover layers","en","report","Rijkswaterstaat, DWW","","","","","","","","","","","","TAW/ENW",""
"uuid:c450be5d-d233-4b5d-ae2f-19daa4d3bc3b","http://resolver.tudelft.nl/uuid:c450be5d-d233-4b5d-ae2f-19daa4d3bc3b","Collected Published Papers 1941-1983","Dietz, D.N.","","1984","","reservoir engineering; product technology; brown coal; coal; subsurface coal gasification","en","book","Delftse Uitgevers Maatschappij","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:98791127-e7ae-40a1-b850-67d575fa1289","http://resolver.tudelft.nl/uuid:98791127-e7ae-40a1-b850-67d575fa1289","Shore protection manual: Volume I and II","Anonymus, A.","TU Delft","1984","Design manual for coastal structures. Note that this manual is replaced by the Coastal Engineering Manual. However, this document contains quite some useful information for present day coastal engineers","coastal engineering; sediment transport; coastal structures; wave action; wave-structure interaction","en","report","USACE","","","","","","","","","","","","",""
"uuid:d59dfb63-9a9c-4370-a399-d6e82b2f2546","http://resolver.tudelft.nl/uuid:d59dfb63-9a9c-4370-a399-d6e82b2f2546","A study on the transmission of sound through flow ducts of varying cross section","Rienstra, S.W.","","1983","A study is made of sound propagation through axially varying ducts with mean flow. Several analytical and numerical approaches are considered, and discussed with respect to their possibilities and limitations. Two new analytical theories, relevant for low and for high frequencies, are worked out in some detail. A fortuitously available *) computer program of one of the most promising semi-analytical methods, A.H. Nayfeh's wave envelope approach (Ref. 1), was tested to see if bottlenecks could be identified, what parameter range is attainable, and to what extent the classical uniform duct model produces satisfactory results. Main observations were that, although in principle amenable to high frequencies and circumferential periodicities, the method has in its present form parts of purely numerical nature, which do not allow a too detailed field; furthermore, for sound propagating into a contraction (the usual case in a turbo engine intake) the prediction of the uniform duct model seems to be always conservative. A spectacular increase of the reflected wave was found for a combination of high Machnumber and thin boundary layer in the contraction.","turbofan engines; acoustic ducts; mathematical methods; sound fields; variable geometry structures; duct walls; joints (junctions); branching (physics); axial flow; shear flow; boundary layers; admittance; damping; impedance; eigen value problems; vessel functions; Runge Kutta method; computer programs","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:aa8d1c6e-f546-4e9e-b42c-fa62375f1ce2","http://resolver.tudelft.nl/uuid:aa8d1c6e-f546-4e9e-b42c-fa62375f1ce2","CAD-systemen voor overdracht van kennis","Loeve, W.; van den Dam, R.F.","","1983","The NLR in the Netherlands renders scientific support and technical assistance for the design and operation of aircraft and spacecraft. The approach of NLR can be characterized by integration of experimental and theoretical investigations. For this an integrated computer and terminal network has been developed that links both NLR laboratory sites. Based on this development, knowledge transfer to other organizations at the moment is realized mainly via computer-based information systems. The CAD systems that belong to these systems have proven to be ideal carriers of technical knowledge. CAD systems to be used in an organization have to be integrated in the existing infrastructure for information processing. As a result, NLR is active in combining the aspects of automation and organization that are relevant for the realization of an integrated infrastructure for information processing.","systems engineering; computer aided design; CAD; aircraft design; technology transfer; computer programs; technology utilization; CDC cyber 170 series computers; research facilities; user requirements; computer networks; Netherlands; mathematical models","nl","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:54500ca8-e6ab-438e-b3e7-983102c690ca","http://resolver.tudelft.nl/uuid:54500ca8-e6ab-438e-b3e7-983102c690ca","The engine/airframe interference drag at cruise conditions using propulsion simulation","Doornbos, G.; de Wolf, W.B.","","1982","A wind tunnel test procedure is described to determine from the thrust minus drag measurements the aircraft drag and engine/airframe interference drag at cruise conditions. The definitions of the thrust and drag terms in use are given. Engine thrust simulation is provided by a calibrated Turbofan Powered Simulator (TPS). Further the use of a blown nacelle as propulsion simulator is described and compared with the simulation by a TPS. It is concluded that TPS engines are valuable test tools, simulating the aircraft engine closely, but the blown nacelle can not be totally replaced by the TPS nacelle; it will retain its own applications","Windtunnel apparatus; Windtunnel models; Interference drag; Engine airframe integration; Aircraft models; Cruising flight; Thrust measurements; Wind tunnel tests; Procedures exhaust flow simulation; Propulsion system performan; Nacelles; Comparison; Turbofan engines","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:4660f23d-92d4-4a62-b794-0a2cb7d59daa","http://resolver.tudelft.nl/uuid:4660f23d-92d4-4a62-b794-0a2cb7d59daa","Coarsening and solutioning of precipitates in superalloys","Kolkman, H.J.","","1981","Coarsening and solutioning of the main strengthening phase for the majority of superalloys, the y' phase, are discussed. It is shown that a general prediction of coarsening rates and solutioning temperatures is possible.","Aging (metallurgy); Diffusion; Heat treatment; Microstructure; Coarsening; Precipitation hardening; Solid solutions; Face centered cubic lattices; Superalloys; Nickel alloys; Iron alloys; Chromium alloys; Temperature effects; Aircraft engines; Turbine blades; Maintenance","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:d7fb0db2-5298-4afd-95a5-404ef0420639","http://resolver.tudelft.nl/uuid:d7fb0db2-5298-4afd-95a5-404ef0420639","The NLR/NGTE joint programme on the measurement of attenuation and impedance in acoustic flow duct facilities.","Zandbergen, T.; Martlew, D.L.","","1981","The National Aerospace Laboratory NLR in the Netherlands and the National Gas Turbine Establishment NOTE operate similar acoustic flow duct facilities but with differences in their respective approaches to the measurement of attenuation and impedance of duct linings. A joint exercise was arranged with the object of comparing methods and results, particularly the direct measurement of impedance with its inference from attenuation measurements.","Aircraft engines; Aeroacoustics; Acoustic measurements; Acoustic transducers; Linings; Acoustic ducts; Test facilities; Acoustic impedance; Transmission loss; Insertion loss","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:223e1657-e6eb-496d-a77a-d037637e48f0","http://resolver.tudelft.nl/uuid:223e1657-e6eb-496d-a77a-d037637e48f0","Functional requirements for a software cost database","Dekker, G.J.; van der Wilt, M.; van den Bosch, F.J.","","1981","Cost estimation of software development and control of the cost during the development, are difficult due to the lack of useful cost figures from previous projects, and consequently due to the lack of an accurate cost estimation and management method. This report describes the results of the first phase of a study to develop a software cost database. This cost database will be used to develop such an accurate cost estimation method and to support cost management. The study is performed under contractnumber 18T0 of the Netherlands Agency for Aerospace prograjns (NIVE). During this first phase, a literature survey has'been performed on software cost estimation techniques and on already available cost data bases. This survey, together with the experience, available at NLR, has led to a proposal for a cost estimation method. To support this method, kj cost factors have been defined. It is felt that the clear definition of those cost factors will be of main importance for the usefullness of the method. The next phase of this study will be the implementation of a cost database, which will contain data about these kj cost factors. This data will be gathered from running projects. The cost database will ultimately be used to determine the constants of the proposed cost estimation method.","Value engineering; Costs; Cost estimates; Databases; Requirements; Lifecycle service life; Computer systems programs; Design; Computer programming; Product development; Project planning; Project management; Software (computers); Manpower","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:aebb32d4-034f-4010-bb9b-a6e986eab3d4","http://resolver.tudelft.nl/uuid:aebb32d4-034f-4010-bb9b-a6e986eab3d4","Man-made islands in Mackenzie River: Evaluation of hydraulic design","Verhagen, H.J.; Loman, G.J.A.","Biesheuvel, G.I. (contributor); Burger, A. (contributor); TU Delft","1980","Norman Hells is situated on the north bank of the Mackenzie River, 145 km south of the Arctic Circle. The use of a pool-wide water flood system for secondary recovery and the features of the oil-bearing structure require six man-made platforms to provide vertical access to the portion of the oil pool that 1 ies beneath the Mackenzie River (60%). With a view to the economic viability of the secondary recovery project, man-made islands - hydraulically filled - represent the least risk of massive failure in connection with the environmental loads to be expected. As the man-made islands predominantly determine the economic feasibility of the expansion project, their design has been kept conservative, reflecting a tried and true construction concept, appl ied under various conditions. The design criteria were established by Esso Resources Canada Ltd. in co-operation with Hydronamic. The 'final' design resulted from several additional studies and computations. This report embraces the results of the above-mentioned studies and computations in hydraul ic engineering focussing on: (1) the computation of surge velocities during the release -of severe river-ice jams; (2) the computation of the degree of damage to the rip-rap slope protection; (3) the prediction of the development of local scour in the river bed adjacent to the rip-rap apron.","artificial island; ice engineering; river breakup; ice jam","en","report","Hydronamic","","","","","","","","","","","","",""
"uuid:1b5f6d23-af03-44ae-90a3-f1bb8c665ef3","http://resolver.tudelft.nl/uuid:1b5f6d23-af03-44ae-90a3-f1bb8c665ef3","Velocity and Pressure Field in Spilling Breakers","Stive, M.J.F.","","1980","","41 Water Utilities (CE); Breaking Waves; CIVIL; Coastal Engineering; Surf Zone; Velocity; Water Waves; Wave Pressure; Wave Velocity","en","conference paper","American Society of Civil Engineers","","","","","","","","","","","","",""
"uuid:2c9d2b6c-9da0-4f7f-bd5e-b8c2d4d5854d","http://resolver.tudelft.nl/uuid:2c9d2b6c-9da0-4f7f-bd5e-b8c2d4d5854d","Explanations tot the characteristic values in the performance log","Sulzer ","","1980","","Diesel engine; performance; characteristics; fuel consumption","","report","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:f5f823d2-20d4-4e3f-9091-b639032a4105","http://resolver.tudelft.nl/uuid:f5f823d2-20d4-4e3f-9091-b639032a4105","Het kortste-tijd routekeuzecriterium: Een empirische toetsing","Bovy, P.H.L.","","1980","","congresverslag TGA / Verkeerskunde: algemeen / Traffic engineering: general verkeerskunde","nl","conference paper","S.n.","","","","","","","","","","","","",""
"uuid:112c5c58-106f-4e5c-bcdc-fee325806f71","http://resolver.tudelft.nl/uuid:112c5c58-106f-4e5c-bcdc-fee325806f71","Duwvaartsluizen in de Philipsdam: Toepasbaarheid geleidendheidsmeetinstrument Rijkswaterstaat Hydro-instrumentatie","Ludikhuize, D.","Deltares","1980","","duwvaartsluizen; electrical engineering; elektrotechniek; locks; measuring instruments; meetinstrumenten; Philipsdam; push tow locks; salt water retention; schutsluizen; Zeeland; zoutwaterkering","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:43dc06d7-063a-41f8-b437-cdbdb4f962eb","http://resolver.tudelft.nl/uuid:43dc06d7-063a-41f8-b437-cdbdb4f962eb","On the sound field generated by a fan in a hard-walled baffled duct with uniform flow","Laan, J.N.; Schulten, J.B.H.M.","","1978","The present status of a method to calculate the generation, transmission and radiation of fan noise is described. A steady uniform flow is assumed in the whole field. A hard-walled circular duct is considered which is terminated at the open end by an infinite baffle. The source mechanism is the impingement of wakes from an upstream blade row giving rise to fluctuating bldde forces. This force field drives the sound field. The method is illustrated by means of numerical examples.","acoustic ducts; acoustic properties; mathematical models; ducted fans; far fields; directivity; sound propagation; sound fields; reflection; wakes; sound pressure; turbo fans; F-28 transport aircraft; density distribution; rotor blades (turbomachinery); Spey Mk-555 engine; prediction analysis techniques","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:e1e7828d-de88-4b77-8912-ac23a4ac62c6","http://resolver.tudelft.nl/uuid:e1e7828d-de88-4b77-8912-ac23a4ac62c6","Coastal Engineering: Glossary and conversion factors","Massie, W.W.","","1978","Glossary in Dutch, English, German and French of coastal engineering terms.","glossary; coastal engineering","en","lecture notes","TU Delft, department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:6d9024df-840b-4ec3-b82e-217f100205d9","http://resolver.tudelft.nl/uuid:6d9024df-840b-4ec3-b82e-217f100205d9","Testing of coatings and materials for jet engine components in simulated operational environments","van der Vet, W.J.","","1977","Military aircraft flying low level missions in Western Europe encounter a very different environment from that in most of the United States. Industrial pullution causes atmospheric moisture to be highly acid, and the corrosion rate of jet engine components is greatly increased, with consequent high maintenance costs. To help combat this problem the National Aerospace Laboratory NLR in the Netherlands has built special test rigs for testing jet engine materials and coatings under simulated environmental conditions. In this paper the test rigs and some results are discussed.","coatings; atmospheric effects; jet engines; turbine blades; heat resistant alloys; protective coatings; environmental tests; corrosion tests; burners; combustion chambers","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:35d30251-bd30-4262-b67b-65d6ddb5bc84","http://resolver.tudelft.nl/uuid:35d30251-bd30-4262-b67b-65d6ddb5bc84","Biezeno en de mechanica - Herdenkingsdag 14 mei 1976.","Geerlings, J.J.P.; Haringx, J.A.; Meijers, P.; Van der Neut, A.","Biezeno, C.B. (contributor)","1976","Presentations at a symposium commemorating the death of prof.dr.ir. C.B. Biezeno on 5 September 1975. Presentations by prof. A. van der Neut, prof. R.G. Boiten, prof. W.T. Koiter, prof. J.P. den Hartog, and prof. J.F. Besseling.","engineering mechanics; applied mechanics; obituary","nl","book","Technische Hogeschool Delft","","","","","","","","Mechanical, Maritime and Materials Engineering","","","","",""
"uuid:a0a8d19d-8918-4327-b071-5cdccacefb4f","http://resolver.tudelft.nl/uuid:a0a8d19d-8918-4327-b071-5cdccacefb4f","Coastal Engineering, vol I, Introduction","Massie, W.W.","","1976","Overview, oceanography, Beaufort scale, short waves, wave speed, shoaling, Types of breakers, wave refraction and diffraction, wave statistics, application of wave statistics, wave data, optimum design, history of harbor development, approach channels, dredging equipment, dredging spoil disposal, breakwaters, seiches, tidal rivers, river tide measurements, density currents in rivers, density currents in harbors, pollution, onshore-offshore transport, longshore sediment transport, mud coasts, coastal formations, deltas, shore protection, offshore engineering.","coastal engineering","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:07e6d251-e4d6-4a7e-bc55-c2260e5ebeee","http://resolver.tudelft.nl/uuid:07e6d251-e4d6-4a7e-bc55-c2260e5ebeee","Coastal Engineering. Volume I: Introduction","Massie, W.W.","Bijker, E.W. (contributor)","1976","Lecture notes: short waves, waves near shoreline, coastal formation, sediment transport by waves, coastal protection, delta coasts, muddy coasts, tidal rivers, density currents.","coastal engineering; collegediktaat f11a","en","lecture notes","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:5cde465c-5f79-44f0-a1a8-4ba0eca414fa","http://resolver.tudelft.nl/uuid:5cde465c-5f79-44f0-a1a8-4ba0eca414fa","De steekproefophoging bij een gedetailleerde interaktiematrix: Enkele problemen en mogelijke oplossingen.","Bovy, P.H.L.","","1976","","congresverslag TGA / Verkeerskunde: algemeen / Traffic engineering: general verkeerskunde","nl","conference paper","Colloquium Vervoersplanologisch Speurwerk","","","","","","","","","","","","",""
"uuid:22ab9ed1-45df-4417-a586-4721ce1ea1a3","http://resolver.tudelft.nl/uuid:22ab9ed1-45df-4417-a586-4721ce1ea1a3","Calculation of acoustic modes in an infinite duct with shear flow and sound absorbing walls","Tiggelaar, J.J.","","1975","The sound field in an infinitely long duct with shear flow and sound absorbing walls, but with the sound source unspecified, is analysed into its constituents, the acoustic duct modes. The equations, wave numbers, and various properties of the modes are discussed. Some calculated results are used to show the effects of shear flow and absorbing walls on the modest refraction and redistribution of acoustic energy. The energy (intensity) calculations are made with the Cantrell-Hart formula. For further work, specific applications of the theory are proposed, together with extensions, notably the inclusion of a sound source","Acoustic ducts; Ducts; Sound propagation; Sound transmission; Shear flow; Sound fields; Propagation modes; Acoustic attenuation; Engine inlets; Noise reduction; N-umerical analysis; Sound intensity; Aircraft noise","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:4ee3b948-f49e-4794-a3f7-eb3be8b02d2d","http://resolver.tudelft.nl/uuid:4ee3b948-f49e-4794-a3f7-eb3be8b02d2d","High temperature gas turbine materials","Wanhill, R.J.H.","","1975","The requirements and problems of high temperature materials in gas turbines are reviewed, with specific reference to turbine discs, blades, vanes and combustion cans. The mechanical and environmental property requirements of these components are discussed, followed by an overview of the types of materials used. Lastly, there is a summary of the problems of creep and stress rupture, low cycle fatigue (including thermal fatigue), oxidation and hot corrosion.","Corrosion; Creep properties; Creep rupture strength; Engine parts; Fatigue; Gas turbines; Heat resistant alloys; High temperature environments; Oxidation; Requirements; Stress cycles; Thermal fatigue","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:55a18f8e-abe0-4a6b-977c-ecc4782d29d1","http://resolver.tudelft.nl/uuid:55a18f8e-abe0-4a6b-977c-ecc4782d29d1","Computer running times of some BPR programs as related to network size","Jansen, G.R.M.; Bovy, P.H.L.","","1973","","TBA / Civiele techniek: algemeen / Civil engineering: general TFN / Verkeers- en vervoersplanning, mobiliteitsonderzoek / Transportation planning, travel behaviour research","en","book","Delft University of Technology","","","","","","","","","","","","",""
"uuid:79c2d09e-fa6a-4518-98a7-16ce997333c1","http://resolver.tudelft.nl/uuid:79c2d09e-fa6a-4518-98a7-16ce997333c1","Introduction to Coastal Engineering and Breakwaters","Bijker, E.W.","","1972","Collegedictaat f11a and f11b. Lecture notes, short waves, waves near shoreline, coastal formation, sediment transport by waves, coastal protection, delta coasts, muddy coasts, tidal rivers, density currents, breakwater design.","coastal engineering; breakwaters; density currents","en","lecture notes","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:9ccbae72-7e8c-4812-9efd-2577883913a9","http://resolver.tudelft.nl/uuid:9ccbae72-7e8c-4812-9efd-2577883913a9","Topics in coastal engineering","Bijker, E.W.","","1972","Harbors, development of longshore current formulas, radiation stress, determination of currents along a coast, longshore sand transportation, local coastal accretion, beaches with groins, wave forces on piles, offshore constructions, offshore moorings, submarine pipelines.","coastal engineering","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:f955c5ab-9ffe-4e35-b60f-eeb64a3efbac","http://resolver.tudelft.nl/uuid:f955c5ab-9ffe-4e35-b60f-eeb64a3efbac","A glossary of coastal engineering terms","Allen, R.H.","TU Delft","1972","","gossary; coastal engineering","en","report","USACE","","","","","","","","","","","","",""
"uuid:57b37fc6-8e3c-4103-aa9b-63990cd8c9d8","http://resolver.tudelft.nl/uuid:57b37fc6-8e3c-4103-aa9b-63990cd8c9d8","ON THE RELEVANCE OF ON-LINE TRAFFIC ENGINEERING","Fu, B.; Uhlig, S.P.W.G.","","","The evaluation of dynamic Traffic Engineering (TE) algorithms is usually carried out using some specific network(s), traffic pattern(s) and traffic engineering objective(s). As the behavior of a TE algorithm is a consequence of the interactions between the network, the traffic demand and the algorithm itself, the relevance of TE may depend on several network design aspects. In this paper, we evaluate well-known TE algorithms using real-world and generated network topologies and traffic demands. By re-scaling observed traffic demands, we are able to observe the behavior of TE algorithms under a variety of situations, which may not be observable in reality. We identify distinct network load regimes that correspond to different behaviors of the TE algorithms. We also study the impact of several network design aspects, like network provisioning and redundancy, on the relevance of TE algorithms. We find that there are specific situations under which TE algorithms are useful. These situations depend highly on shortcomings in the network provisioning as well as on the availability of alternative paths in the network.","traffic engineering; network provisioning; network design","en","conference paper","International Teletraffic Congress (ITC)","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Network Architectures and Services","","","",""
"uuid:670ee23a-6d35-41c6-9a1a-becf93bcc0ea","http://resolver.tudelft.nl/uuid:670ee23a-6d35-41c6-9a1a-becf93bcc0ea","Coastal Engineering","Bijker, E.W.","","1970","Overview of coastal processes and coastal structures.","coastal engineering","en","lecture notes","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:b6b9f68f-ad44-425f-91e3-67f9946092cc","http://resolver.tudelft.nl/uuid:b6b9f68f-ad44-425f-91e3-67f9946092cc","Lecture notes on ""The Role of Rivers to Mankind""","Berdenis van Berlekom, H.A.","NEDECO","1969","It is the task and target of River Engineering as a profession to provide all the tools for arriving at an optimum utilization of the potential resources, optimum in the sense of promoting the beneficial characteristics of the river and eliminating or at least checking the adverse qualities. To strive for this aim, there must be a scientific understanding of the complex pattern of natural forces that exert their influence; a general knowledge on what we call the phenomenon ""River"". These lecture notes try to provide this understanding. In specific, it will provide insight into the following subjects related to the ""River"": - The river's functions - The longitudinal profile - (In)dependent variables in the river valley - Water movement - Sediment movement - Bed formation in a straight river - Cross-sections of a river in a bend - Features of cross-sections in a long narrowed section - Rivers under natural conditions Furthermore, the lecture notes include some improvement schemes in which improvements are described step-by-step. This section especially focuses on regulation and normalization.","morphology; rivers; river engineering; river regulation; river management; river profile; hydraulics; river processes","en","report","Polish Academy of Sciences Institute of Hydro-Engineering, Gdańsk","","","","","","","","","","","","Selected Problems from the Theory of Simulation of Hydrodynamic Phenomena",""
"uuid:d9455958-c9f2-44cb-92e7-2e36ab33282e","http://resolver.tudelft.nl/uuid:d9455958-c9f2-44cb-92e7-2e36ab33282e","Coastal Engineering - Santa Barbara Specialty Conferences","Saville, T.","TU Delft","1965","Conference on various aspects of coastal engineering; additional to the International Conference of Coastal Engineering. In table of contents are links to the full papers.","coastal engineering","en","report","ASCE","","","","","","","","","","","","",""
"uuid:1f1549fa-64a6-426e-8377-d83b5a6500bf","http://resolver.tudelft.nl/uuid:1f1549fa-64a6-426e-8377-d83b5a6500bf","Probleme der Donau in Österreich","Grzywienski, A.","","1963","Overview of the hydraulic works in the upper part of the Danube river.","Danube; hydraulic engineering; river engineering","de","book chapter","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:1ff6149b-67ff-44b0-807e-1331608b61a5","http://resolver.tudelft.nl/uuid:1ff6149b-67ff-44b0-807e-1331608b61a5","Évolution, depuis trente ans, de la normalisation internationale des mesures de débits en conduite","Schlag, A.","","1963","Historical overview regarding the standardization of discharge measurements.","discharge; hydraulic engineering; flow","fr","book chapter","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:2294d42d-4ce8-4a3f-8997-a7e29815d37f","http://resolver.tudelft.nl/uuid:2294d42d-4ce8-4a3f-8997-a7e29815d37f","Activities of Dutch civil engineers abroad","Frijlink, H.C.","","1963","Activities of Dutch engineering consultants in Nedeco framework abroad.","hydraulic engineering; consultancy; developing countries","en","book chapter","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:9f153965-f0b0-401c-8cec-5d346e0b3650","http://resolver.tudelft.nl/uuid:9f153965-f0b0-401c-8cec-5d346e0b3650","The International Course in Hydraulic Engineering","Quik, H.G.","","1963","The history of the international courses (IHE) and the role of NUFFIC; overview of participation in the courses, international perspective.","education; developing countries; international course; hydraulic engineering","en","book chapter","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:a46ffcbb-59b8-4f33-8012-eb82b6b1afb8","http://resolver.tudelft.nl/uuid:a46ffcbb-59b8-4f33-8012-eb82b6b1afb8","Coastal Engineering","van Veen, J.","WL Delft","1961","Description of coastal engineering, with focus on lowland, deltaic coasts (the Netherlands), description of estuaries, coastal protection works.","tidal hydraulics; coastal protection; coastal engineering","en","report","Butterworth, London","","","","","","","","","","","","",""
"uuid:e32906b8-a248-412a-9611-ea28d8a08231","http://resolver.tudelft.nl/uuid:e32906b8-a248-412a-9611-ea28d8a08231","Rapport Deltacommissie. Deel 4. Bijdragen 3: Beschouwingen over stormvloeden en getijbeweging","Maris, A.G.; De Blocq van Kuffeler, V.J.P.; Harmsen, W.J.H.; Jansen, P.P.; Nijhoff, G.P.; Thijsse, J.T.; Verloren van Themaat, R.; De vries, J.W.; Van der Wal, L.T.","Rijkswaterstaat (contributor)","1961","Uitgebracht door de commissie van advies inzake de beantwoording van de vraag, welke waterstaatstechnische voorzieningen dienen te worden getroffen met betrekking tot de door de stormvloed van 1 februari 1953 geteisterde gebieden (deltacommissie), ingesteld bij beschikking van de minister van verkeer en waterstaat van 18 februari 1953.","Deltacommissie 1961, Coastal engineering","nl","report","SDU","","","","","","","","","","","","",""
"uuid:4f6cc878-b1d0-4b1b-a64c-f6fe74260579","http://resolver.tudelft.nl/uuid:4f6cc878-b1d0-4b1b-a64c-f6fe74260579","Rapport Deltacommissie. Deel 6. Bijdragen 5: Onderzoekingen van belang voor het ontwerpen van dijken en dammen - Bijdragen 6: Sociaal-economische aspecten van het Deltaplan","Maris, A.G.; De Blocq van Kuffeler, V.J.P.; Harmsen, W.J.H.; Jansen, P.P.; Nijhoff, G.P.; Thijsse, J.T.; Verloren van Themaat, R.; De vries, J.W.; Van der Wal, L.T.","Rijkswaterstaat, Waterloopkundig Laboratorium Werkgroep voor het onderzoek naar de spanningstoestand in zeedijken (contributor)","1961","UITGEBRACHT DOOR DE COMMISSIE VAN ADVIES INZAKE DE BEANTWOORDING VAN DE VRAAG, WELKE WATERSTAATSTECHNISCHE VOORZIENINGEN DIENEN TE WORDEN GETROFFEN MET BETREKKING TOT DE DOOR DE STORMVLOED VAN 1 FEBRUARI 1953 GETEISTERDE GEBIEDEN (DELTACOMMISSIE), INGESTELD BIJ BESCHTKKING VAN DE MINISTER VAN VERKEER EN WATERSTAAT VAN 18 FEBRUARI 1953","Deltacommissie 1961, Coastal engineering","nl","report","SDU","","","","","","","","","","","","",""
"uuid:046f06e8-5127-4e49-adfd-a496b4fedbb5","http://resolver.tudelft.nl/uuid:046f06e8-5127-4e49-adfd-a496b4fedbb5","Rapport Deltacommissie. Deel 3. Bijdragen 2: Beschouwingen over stormvloeden en getijbeweging","Maris, A.G.; De Blocq van Kuffeler, V.J.P.; Harmsen, W.J.H.; Jansen, P.P.; Nijhoff, G.P.; Thijsse, J.T.; Verloren van Themaat, R.; De vries, J.W.; Van der Wal, L.T.","Mathematisch Centrum (contributor)","1961","UITGEBRACHT DOOR DE COMMISSIE VAN ADVIES INZAKE DE BEANTWOORDING VAN DE VRAAG, WELKE WATERSTAATSTECHNISCHE VOORZIENINGEN DIENEN TE WORDEN GETROFFEN MET BETREKKING TOT DE DOOR DE STORMVLOED VAN 1 FEBRUARI 1953 GETEISTERDE GEBIEDEN (DELTACOMMISSIE), INGESTELD BIJ BESCHTKKING VAN DE MINISTER VAN VERKEER EN WATERSTAAT VAN 18 FEBRUARI 1953","Deltacommissie 1961, Coastal engineering","en","report","SDU","","","","","","","","","","","","",""
"uuid:c1b68c35-5a19-4587-b7a7-d0ae19632397","http://resolver.tudelft.nl/uuid:c1b68c35-5a19-4587-b7a7-d0ae19632397","Rapport Deltacommissie. Deel 5. Bijdragen 4: Onderzoekingen betreffende de opzet van het Deltaplan en de gevolgen van de werken","Maris, A.G.; De Blocq van Kuffeler, V.J.P.; Harmsen, W.J.H.; Jansen, P.P.; Nijhoff, G.P.; Thijsse, J.T.; Verloren van Themaat, R.; De vries, J.W.; Van der Wal, L.T.","Rijkswaterstaat (contributor)","1961","UITGEBRACHT DOOR DE COMMISSIE VAN ADVIES INZAKE DE BEANTWOORDING VAN DE VRAAG, WELKE WATERSTAATSTECHNISCHE VOORZIENINGEN DIENEN TE WORDEN GETROFFEN MET BETREKKING TOT DE DOOR DE STORMVLOED VAN 1 FEBRUARI 1953 GETEISTERDE GEBIEDEN (DELTACOMMISSIE), INGESTELD BIJ BESCHTKKING VAN DE MINISTER VAN VERKEER EN WATERSTAAT VAN 18 FEBRUARI 1953","Deltacommissie 1961, Coastal engineering","en","report","SDU","","","","","","","","","","","","",""
"uuid:0e28dfd8-4e67-4267-a443-54b74a062bcb","http://resolver.tudelft.nl/uuid:0e28dfd8-4e67-4267-a443-54b74a062bcb","Rapport Deltacommissie. Deel 1. Eindverslag en interimadviezen","Maris, A.G.; De Blocq van Kuffeler, V.J.P.; Harmsen, W.J.H.; Jansen, P.P.; Nijhoff, G.P.; Thijsse, J.T.; Verloren van Themaat, R.; De vries, J.W.; Van der Wal, L.T.","","1961","UITGEBRACHT DOOR DE COMMISSIE VAN ADVIES INZAKE DE BEANTWOORDING VAN DE VRAAG, WELKE WATERSTAATSTECHNISCHE VOORZIENINGEN DIENEN TE WORDEN GETROFFEN MET BETREKKING TOT DE DOOR DE STORMVLOED VAN 1 FEBRUARI 1953 GETEISTERDE GEBIEDEN (DELTACOMMISSIE), INGESTELD BIJ BESCHTKKING VAN DE MINISTER VAN VERKEER EN WATERSTAAT VAN 18 FEBRUARI 1953","Deltacommissie 1961, Coastal engineering","nl","report","SDU","","","","","","","","","","","","",""
"uuid:93c93f77-6dfa-464f-97c1-8e76858342c4","http://resolver.tudelft.nl/uuid:93c93f77-6dfa-464f-97c1-8e76858342c4","Rapport Deltacommissie. Deel. 2. Bijdragen 1: Meteorologische en oceanografische aspecten van stormvloeden op de Nederlandse kust","Maris, A.G.; De Blocq van Kuffeler, V.J.P.; Harmsen, W.J.H.; Jansen, P.P.; Nijhoff, G.P.; Thijsse, J.T.; Verloren van Themaat, R.; De vries, J.W.; Van der Wal, L.T.","Koninklijk Nederlands Meteorologisch Instituut KNMI (contributor)","1961","UITGEBRACHT DOOR DE COMMISSIE VAN ADVIES INZAKE DE BEANTWOORDING VAN DE VRAAG, WELKE WATERSTAATSTECHNISCHE VOORZIENINGEN DIENEN TE WORDEN GETROFFEN MET BETREKKING TOT DE DOOR DE STORMVLOED VAN 1 FEBRUARI 1953 GETEISTERDE GEBIEDEN (DELTACOMMISSIE), INGESTELD BIJ BESCHTKKING VAN DE MINISTER VAN VERKEER EN WATERSTAAT VAN 18 FEBRUARI 1953","Deltacommissie 1961, Coastal engineering","nl","report","SDU","","","","","","","","","","","","",""
"uuid:a21d6ecd-6c2b-4871-85d7-15836a4a0430","http://resolver.tudelft.nl/uuid:a21d6ecd-6c2b-4871-85d7-15836a4a0430","Coasts, estuaries and tidal hydraulics","Van Veen, J.","","1951","Description of coastal engineering, with focus on lowland, deltaic coasts (the Netherlands), description of estuaries, coastal protection works","coastal protection; coastal engineering; tidal hydraulics","en","report","Butterworths, London","","","","","","","","","","","","",""
"uuid:5c12e11b-a0fc-4245-a23f-4bbc75571c33","http://resolver.tudelft.nl/uuid:5c12e11b-a0fc-4245-a23f-4bbc75571c33","Coastal Engineering (Proceedings of the 1st ICCE, International Conference on Coastal Engineering)","Johnson, J.W.","TU Delft","1951","The Conference on Coastal Engineering at Long Beach was conceived originally as a local meeting of engineers and scientists interested in shoreline problems and was sponsored by the University of California. It early became evident that there was widespread interest in the subject and that the program should be planned on a more ambitious scale. The aim was to aid engineers by summarizing the present state of the art and science related to the design and planning of coastal works rather than to present a series of original scientific contributions. Starting from a rather comprehensive outline, invitations were issued to recognized authorities to report on specific phases of the subject, and the authors cooperated splendidly both in their treatment of the subjects assigned and in their avoidance of overlapping other subjects. Although much remains to be done in the way of developing reliable design methods, the series of papers presented at the conference and published in this volume do represent a rather thorough summary of coastal engineering as now practiced. Engineers engaged in the design of coastal works have had available to them a large number of papers dealing with various phases of the science related to their problems, but proper dealing with design were limited in number and scope. Only a few books on coastal engineering have been published. The quality and scope of the papers and the need for a comprehensive and modern treatment of the subject convinced the sponsors of the conference that publication in a single volume was desirable rather than piecemeal in the scientific and technical journals. The newly-formed Council on Wave Research secured funds to underwrite the publication costs from its parent organization, the Engineering Foundation. A word about the term ""Coastal Engineering"" is perhaps in order here. It is not a new or separate branch of engineering and there is no implication intended that a new breed of engineer, and a new society, is in the making. Coastal Engineering is primarily a branch of Civil Engineering which leans heavily on the sciences of oceanography, meteorology, fluid mechanics, electronics, structural mechanics, and others. However, it is also true that the design of coastal works does involve many criteria which are foreign to other phases of civil engineering and the novices in this field should proceed with caution. Along the coastlines of the world, numerous engineering works in various stages of disintegration testify to the futility and wastefulness of disregarding the tremendous destructive forces of the sea. Far worse than the destruction of insubstantial coastal works has been the damage to adjacent shorelines caused by structures planned in ignorance of, and occasionally in disregard of, the shoreline processes operative in the area. The Council on Wave Research takes this opportunity to thank the authors of the papers and the many others who assisted in organization of the conference and in the preparation of this volume for publication.","Coastal Engineering; Coastal Morphology; Breakwaters; Coastal Structures","en","report","ASCE","","","","","","","","","","","","",""
"uuid:075c8814-819e-4ca2-a3a1-3959aec8ab0d","http://resolver.tudelft.nl/uuid:075c8814-819e-4ca2-a3a1-3959aec8ab0d","De beteekenis der Wiskunde als Hulpwetenschap der Toegepaste Mechanica. Rede, uitgesproken bij de aanvaarding van het Ambt van Hoogleraar in de Toegepaste Mechanica aan de Technische Hoogeschool te Delft, den 30en September 1914.","Biezeno, C.B.","","1914","Intreerede van prof.ir. C.B. Biezeno.","Intreerede; toegepaste mechanica; engineering mechanics; applied mechanics","nl","public lecture","Academische Boekhandel en Drukkerij J. Waltman Jr.","","","","","","","","Mechanical, Maritime and Materials Engineering","","","","",""