"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:08100443-b972-48cc-9582-ec2478cc247f","http://resolver.tudelft.nl/uuid:08100443-b972-48cc-9582-ec2478cc247f","The impact of modulational instability on coastal wave forecasting using quadratic models","Akrish, G. (TU Delft Environmental Fluid Mechanics); Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics); Zijlema, Marcel (TU Delft Environmental Fluid Mechanics); Smit, P.B. (Sofar Ocean Technologies)","","2024","Coastal wave forecasting over large spatial scales is essential for many applications (e.g., coastal safety assessments, coastal management and developments, etc.). This demand explains the necessity for accurate yet effective models. A well-known efficient modelling approach is the quadratic approach (often referred to as frequency-domain models, nonlinear mild-slope models, amplitude models, etc.). The efficiency of this approach stems from a significant modelling reduction of the original governing equations (e.g., Euler equations). Most significantly, the description of wave nonlinearity essentially collapses into a single mode coupling term determined by the quadratic interaction coefficients. As a result, it is expected that the efficiency achieved by the quadratic approach is accompanied by a decrease in prediction accuracy. In order to gain further insight into the predictive capabilities of this modelling approach, this study examines six different quadratic formulations, three of which are of the Boussinesq type and the other three are referred to as fully dispersive. It is found that while the Boussinesq formulations reliably predict the evolution of coastal waves, the predictions by the fully dispersive formulations tend to be affected by false developments of modulational instability. Consequently, the predicted wave fields by the fully dispersive formulations are characterized by unexpectedly strong modulations of the sea-swell part and associated unexpected infragravity response. The impact of the modulational instability on wave prediction based on the quadratic approach is further demonstrated using existing laboratory results of bichromatic and irregular wave conditions.","Modulation instability; Spectral modelling; Quadratic modelling; Coastal waves; Wave nonlinearity; Infragravity waves","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:26c82303-0b72-4b8f-961c-40a5cfe9540a","http://resolver.tudelft.nl/uuid:26c82303-0b72-4b8f-961c-40a5cfe9540a","A quantitative comparison between the mHand Adapt passive adjustable hand prosthesis and its predecessor, the Delft Self-Grasping Hand","Krinis, S.L.L. (Student TU Delft; University of Salford); Chadwell, Alix (University of Salford); Kenney, Laurence (University of Salford); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2024","Introduction
The Delft Self-Grasping Hand (SGH) is an adjustable passive hand prosthesis that relies on wrist flexion to adjust the aperture of its grasp. The mechanism requires engagement of the contralateral hand meaning that hand is not available for other tasks. A commercialised version of this prosthesis, known as the mHand Adapt, includes a new release mechanism, which avoids the need to press a release button, and changes to the hand shape. This study is the first of its kind to compare two passive adjustable hand prostheses on the basis of quantitative scoring and contralateral hand involvement.
Methods
10 anatomically intact participants were asked to perform the Southampton Hand Assessment Procedure (SHAP) with the mHand. Functionality and contralateral hand involvement were recorded and compared against SGH data originating from a previous trial involving a nearly identical testing regime.
Results
mHand exhibited higher functionality scores and less contralateral hand interaction time, especially during release-aiding interactions. Additionally, a wider range of tasks could be completed using the mHand than the SGH.
Discussion
Geometric changes make the mHand more capable of manipulating smaller objects. The altered locking mechanism means some tasks can be performed without any contralateral hand involvement and a higher number of tasks do not require contralateral involvement when releasing. Some participants struggled with achieving a good initial grip due to the inability to tighten the grasp once already formed.
Conclusion
The mHand offers the user higher functionality scores with less contralateral hand interaction time and the ability to perform a wider range of tasks. However, there are some design trade-offs which may make it slightly harder to learn to use.
18F]FDG-PET/computed tomography (CT) for this group of long COVID patients. Methods For this proof of concept study, we evaluated [ 18F]FDG-PET/CT scans of long COVID patients and controls. Two analyses were performed: semi-quantitative analysis using target-to-background ratios (TBRs) in 24 targets and total vascular score (TVS) assessed by two independent nuclear medicine physicians. Mann-Whitney U-test was performed to find significant differences between the two groups. Results Thirteen patients were included in the long COVID group and 25 patients were included in the control group. No significant differences (P < 0.05) were found between the long COVID group and the control group in the TBR or TVS assessment. Conclusion As we found no quantitative difference in the TBR or TVS between long COVID patients and controls, we are unable to prove that [ 18F]FDG is of added value for long COVID patients with symptoms of myalgia or joint pain. Prospective cohort studies are necessary to understand the underlying mechanisms of long COVID.","","en","journal article","","","","","","","","","","RST/Radiation, Science and Technology","","","",""
"uuid:9206ad65-b2b9-4b0a-9e14-78c7e2da9ae4","http://resolver.tudelft.nl/uuid:9206ad65-b2b9-4b0a-9e14-78c7e2da9ae4","Partial discharge detection on power equipment using a magneto-resistive sensor","Chen, Y. (TU Delft DC systems, Energy conversion & Storage; South China University of Technology); Castro Heredia, L.C. (TU Delft ESP LAB); Smit, J.J. (TU Delft EEMS - General; IWO (Inst. for Science & Development / Inst. voor Wetenschap & Ontwikkeling)); Ghaffarian Niasar, M. (TU Delft High Voltage Technology Group); Ross, Robert (TU Delft High Voltage Technology Group; IWO (Inst. for Science & Development / Inst. voor Wetenschap & Ontwikkeling))","","2023","Partial discharges (PD) detection is an effective diagnostic method to assess the insulation condition of electrical power equipment in the high-voltage laboratory or field tests. This paper presents a non-contacting PD detection method for power equipment. The method is based on an extra high-sensitivity adapted giant magneto-resistive (xMR) sensor that measures the magnetic field produced by the PD currents. Firstly, this paper describes the sensor’s relevant principle and signal conditioning circuit. Next, the sensor’s typical performance, including the frequency response and time-domain response to calibrator PD pulses, is measured and compared with our previous work. The results indicate that the xMR system’s bandwidth is improved to the MHz range. Finally, PD experiments are carried out and compared with measurements using a commercially available high-frequency current transformer (HFCT), which allows for verification of the coherence of the results concerning the PD pulses and phase-resolved PD (PRPD) patterns. The results show that PD in a cross-linked polyethylene (XLPE) cable or a gas-insulated system (GIS) with artificial discharging defects is successfully measured, demonstrating the sensitivity and performance of the xMR system for PD detection.","Cross-linked polyethylene (XLPE) cable; (Electro)magnetic field measurement; Giant magneto-resistive (GMR); Gas-insulated systems (GIS); High-frequency current transformers (HFCT); Partial discharges (PD); Sensors","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:8d484c86-5071-4ad8-867d-8501f55dcc71","http://resolver.tudelft.nl/uuid:8d484c86-5071-4ad8-867d-8501f55dcc71","Design and evaluation of the pneumatic leg prosthesis ERiK to assist elderly amputees with sit-down and stand-up movements","Vallery, H. (TU Delft Biomechatronics & Human-Machine Control; Erasmus MC); Lachmann, F. (TU Delft Biomechatronics & Human-Machine Control); van der Helm, S.G. (Student TU Delft); Pennycott, A. (TU Delft Biomechatronics & Human-Machine Control); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2023","Standing up using one leg is a challenging task for those with a transfemoral amputation, particularly for elderly users with a low activity level. Active prostheses are generally not accessible to this group and available passive prostheses do not support standing up. This article presents the design and evaluation of the “Energy Restoring Intelligent Knee” (ERiK), which stores energy during sit-down in a pneumatic cylinder and returns it during stand-up. We hypothesized that the system would reduce the time needed to perform transitions and also enable higher load sharing by the prosthetic leg. However, the results of an experimental study with seven participants with transfemoral amputation contradict these hypotheses: the participants could neither move faster nor make more use of the prosthetic leg to share their body weight during transitions. We observed that a major obstacle to the useful functionality of the leg was the absence of ankle dorsiflexion – the foot tended to slip during stand-up initiation, such that only low pre-pressures and therefore support levels could be set. The rather binary action of the pneumatics also complicated movement initiation. The lessons learned from this study may be helpful to those seeking to create better designs in the future.","Knee exoprosthesis; sit-to-stand; lightweight pneumatic actuator; transfemoral amputation","en","journal article","","","","","","","","","","","Biomechatronics & Human-Machine Control","","",""
"uuid:f49cce17-15b9-4c9b-b100-6b6b78da1dd0","http://resolver.tudelft.nl/uuid:f49cce17-15b9-4c9b-b100-6b6b78da1dd0","FinFix: A Soft Gripper With Contact-Reactive Reflex for High-Speed Pick and Place of Fragile Objects","Heeringa, W.M. (Student TU Delft); Della Santina, C. (TU Delft Learning & Autonomous Control); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2023","Industrial automation calls for precise tasks with cycle times reduced to the minimum. At the same time, when handling delicate products such as fruits and vegetables, accelerations must be kept low to keep interaction forces under a certain threshold to avoid damage. This trade-off hinders the penetration of automation in many relevant application fields. This paper investigates using soft technology to solve this challenge. We propose the FinFix gripper, a non-anthropomorphic soft gripper capable of handling delicate objects at high acceleration using a contact-reactive grasping approach. This gripper has two entirely passive sensorized fingers that establish contact and two active fingers that are actuated pneumatically through a rigid mechanism allowing for rapid closure. We provide exhaustive experimental validation by connecting the gripper to a delta robot. The system can reliably execute pick-and-place cycles in ∼1 s when the distance between the pick and the place locations is 400 mm, resulting in a peak speed of ∼10ms . None of the fragile objects used during the experiments showed any damage. The only information needed is a rough estimation of the object's position to be grasped and a contact event to trigger the reflex. The test results show that the gripper can hold fragile objects during lateral accelerations of 10g.","","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.","","2023-10-15","","","Learning & Autonomous Control","","",""
"uuid:38dd500a-7e71-4ae1-9b38-3d8c756c2637","http://resolver.tudelft.nl/uuid:38dd500a-7e71-4ae1-9b38-3d8c756c2637","The future of artificial intelligence in intensive care: moving from predictive to actionable AI","Smit, J.M. (TU Delft Pattern Recognition and Bioinformatics; Erasmus MC); Krijthe, J.H. (TU Delft Pattern Recognition and Bioinformatics); van Bommel, Jasper (Erasmus MC); van Genderen, M. E.; Labrecque, J. A.; Komorowski, M.; Gommers, D.A.M.P.J. (TU Delft Biomechanical Engineering); Reinders, M.J.T. (TU Delft Pattern Recognition and Bioinformatics)","","2023","Artificial intelligence (AI) research in the intensive care unit (ICU) mainly focuses on developing models (from linear regression to deep learning) to predict out-
comes, such as mortality or sepsis [1, 2]. However, there is another important aspect of AI that is typically not framed as AI (although it may be more worthy of the name), which is the prediction of patient outcomes or events that would result from different actions, known as causal inference [3, 4]. This aspect of AI is crucial for decision-making in the ICU. To emphasize the impor- tance of causal inference, we propose to refer to any data- driven model used for causal inference tasks as ‘action- able AI’, as opposed to ‘predictive AI’, and discuss how these models could provide meaningful decision support in the ICU.","","en","journal article","","","","","","","","","","Biomechanical Engineering","Pattern Recognition and Bioinformatics","","",""
"uuid:68831a5a-2093-4e33-88d2-bb4b51f15946","http://resolver.tudelft.nl/uuid:68831a5a-2093-4e33-88d2-bb4b51f15946","Experimental Validation of Functional Iterative Learning Control on a One-Link Flexible Arm","Drost, S.C. (Student TU Delft); Pustina, P. (TU Delft Learning & Autonomous Control); Angelini, Franco (University of Pisa); De Luca, Alessandro (Sapienza University of Rome); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Della Santina, C. (TU Delft Learning & Autonomous Control)","","2023","Performing precise, repetitive motions is essential in many robotic and automation systems. Iterative learning control (ILC) allows determining the necessary control command by using a very rough system model to speed up the process. Functional iterative learning control is a novel technique that promises to solve several limitations of classic ILC. It operates by merging the input space into a large functional space, resulting in an over-determined control task in the iteration domain. In this way, it can deal with systems having more outputs than inputs and accelerate the learning process without resorting to model discretizations. However, the framework lacks so far a validation in experiments. This paper aims to provide such experimental validation in the context of robotics. To this end, we designed and built a one-link flexible arm that is actuated by a stepper motor, which makes the development of an accurate model more challenging and the validation closer to the industrial practice. We provide multiple experimental results across several conditions, proving the feasibility of the method in practice.","","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.","","2024-01-04","","","Learning & Autonomous Control","","",""
"uuid:cd67187b-74ac-460e-b974-bc0d55ce56d3","http://resolver.tudelft.nl/uuid:cd67187b-74ac-460e-b974-bc0d55ce56d3","Prediction of particulate fouling in full-scale reverse osmosis plants using the modified fouling index – ultrafiltration (MFI-UF) method","Abunada, M.B.M. (TU Delft Sanitary Engineering; IHE Delft Institute for Water Education); Dhakal, Nirajan (IHE Delft Institute for Water Education); Gulrez, Raffay (IHE Delft Institute for Water Education); Li, L. (TU Delft Sanitary Engineering; IHE Delft Institute for Water Education); Abushaban, Almotasembellah (Mohammed VI Polytechnic University); Smit, Herman (PWN Drinking Water Supply Company); Moed, David (Evides Industriewater); Ghaffour, Noreddine (King Abdullah University of Science and Technology); Kennedy, M.D. (TU Delft Sanitary Engineering; IHE Delft Institute for Water Education)","","2023","This study aims at applying and verifying the MFI-UF method to predict particulate fouling in RO plants. Two full-scale RO plants treating surface water, with average capacity of 800–2000 m3/h, were studied. Firstly, the MFI-UF of RO feed and concentrate was measured using 5–100 kDa membranes at same flux applied in the RO plants (20–26 L/m2.h). Subsequently, the particle disposition factor (Ω) was calculated to simulate particle deposition in RO cross-flow filtration. Finally, particulate fouling rates were predicted based on MFI-UF and Ω, and compared with the actual fouling rates in the plants. For plant A, the results showed that the fouling rates predicted using MFI-UF measured with 100 kDa membrane have the best agreement with the actual fouling (with 3–11 % deviation). For plant B, the fouling rates predicted based on both 10 and 100 kDa membranes agree well with the actual fouling (with 2 % and 15 % deviation, respectively). However, the fouling predicted based on 5 kDa membrane is considerably overestimated for both plants, which is attributed to the effect of the low surface porosity of 5 kDa membrane. More widespread applications of MFI-UF in full-scale RO plants are required to demonstrate the most suitable MFI-UF membranes for fouling prediction.","Membrane surface porosity correction; MFI-UF; Particle deposition factor; Particulate fouling prediction; Reverse osmosis (RO)","en","journal article","","","","","","","","","","","Sanitary Engineering","","",""
"uuid:8f270477-1c68-4afa-928e-dfd2bd2fad22","http://resolver.tudelft.nl/uuid:8f270477-1c68-4afa-928e-dfd2bd2fad22","Puddle formation and persistent gaps across the non-mean-field breakdown of superconductivity in overdoped (Pb,Bi)2Sr2CuO6+δ","Tromp, Willem O. (Universiteit Leiden); Benschop, Tjerk (Universiteit Leiden); Ge, Jian Feng (Universiteit Leiden); Battisti, Irene (Universiteit Leiden); Bastiaans, K.M. (TU Delft QN/Otte Lab; Universiteit Leiden; Kavli institute of nanoscience Delft); Chatzopoulos, Damianos (Universiteit Leiden); Vervloet, Amber H.M. (Universiteit Leiden); Smit, Steef (Universiteit van Amsterdam); Yin, Yi (Nanjing University; Zhejiang University)","","2023","The cuprate high-temperature superconductors exhibit many unexplained electronic phases, but the superconductivity at high doping is often believed to be governed by conventional mean-field Bardeen–Cooper–Schrieffer theory1. However, it was shown that the superfluid density vanishes when the transition temperature goes to zero2,3, in contradiction to expectations from Bardeen–Cooper–Schrieffer theory. Our scanning tunnelling spectroscopy measurements in the overdoped regime of the (Pb,Bi)2Sr2CuO6+δ high-temperature superconductor show that this is due to the emergence of nanoscale superconducting puddles in a metallic matrix4,5. Our measurements further reveal that this puddling is driven by gap filling instead of gap closing. The important implication is that it is not a diminishing pairing interaction that causes the breakdown of superconductivity. Unexpectedly, the measured gap-to-filling correlation also reveals that pair breaking by disorder does not play a dominant role and that the mechanism of superconductivity in overdoped cuprate superconductors is qualitatively different from conventional mean-field theory.","","en","journal article","","","","","","","","","","","QN/Otte Lab","","",""
"uuid:35449db8-cabc-453b-ae74-685ca1f45811","http://resolver.tudelft.nl/uuid:35449db8-cabc-453b-ae74-685ca1f45811","Machine learning for RANS turbulence modeling of variable property flows","Diez Sanhueza, R.G. (TU Delft Energy Technology); Smit, S.H.H.J. (TU Delft Energy Technology); Peeters, J.W.R. (TU Delft Energy Technology); Pecnik, Rene (TU Delft Energy Technology)","","2023","This paper presents a machine learning methodology to improve the predictions of traditional RANS turbulence models in channel flows subject to strong variations in their thermophysical properties. The developed formulation contains several improvements over the existing Field Inversion Machine Learning (FIML) frameworks described in the literature. We first showcase the use of efficient optimization routines to automatize the process of field inversion in the context of CFD, combined with the use of symbolic algebra solvers to generate sparse-efficient algebraic formulas to comply with the discrete adjoint method. The proposed neural network architecture is characterized by the use of an initial layer of logarithmic neurons followed by hyperbolic tangent neurons, which proves numerically stable. The machine learning predictions are then corrected using a novel weighted relaxation factor methodology, that recovers valuable information from otherwise spurious predictions. Additionally, we introduce L2 regularization to mitigate over-fitting and to reduce the importance of non-essential features. In order to analyze the results of our deep learning system, we utilize the K-fold cross-validation technique, which is beneficial for small datasets. The results show that the machine learning model acts as an excellent non-linear interpolator for DNS cases well-represented in the training set. In the most successful case, the L-infinity modeling error on the velocity profile was reduced from 23.4% to 4.0%. It is concluded that the developed machine learning methodology corresponds to a valid alternative to improve RANS turbulence models in flows with strong variations in their thermophysical properties without introducing prior modeling assumptions into the system.","Machine learning; Turbulence modeling; Variable properties","en","journal article","","","","","","","","","","","Energy Technology","","",""
"uuid:7ead94d8-ef32-4e86-9ab1-e79262142878","http://resolver.tudelft.nl/uuid:7ead94d8-ef32-4e86-9ab1-e79262142878","Thermal management in radical induced cationic frontal polymerisation for optimised processing of fibre reinforced polymers","Staal, Jeroen (Swiss Federal Institute of Technology); Smit, Edgar (Swiss Federal Institute of Technology); Caglar, Baris (TU Delft Aerospace Manufacturing Technologies); Michaud, Véronique (Swiss Federal Institute of Technology)","","2023","Radical induced cationic frontal polymerisation (RICFP) is considered a promising low energy method for processing of fibre reinforced polymers (FRPs). Optimisation of the local heat balance between reinforcement, epoxy resin and the surrounding mould is required to pave the way for its adaptation to an industrial processing method for high volume fraction structural fibre reinforced composites. In this work, we investigate several methods to control the governing heat balance in RICFP-processing of FRPs. Heat generation was controlled by tuning the initiator concentration while limitation of heat losses using highly insulating moulds was found beneficial to the front characteristics and resulting curing degrees. An optimised mould configuration allowed for self-sustaining RICFP in FRPs with fibre volume fractions (Vfs) up to 45.8%, exceeding previously reported maxima of similar systems. A process window was moreover established relating the Vf and required heat generation to the potential formation of a self-sustaining or supported front.","Fiber reinforced polymers; Frontal polymerisation; Out-of-autoclave processing; Polymer-matrix composites (PMCs)","en","journal article","","","","","","","","","","","Aerospace Manufacturing Technologies","","",""
"uuid:25f0cbb4-b614-475d-8f34-332b07fa6a45","http://resolver.tudelft.nl/uuid:25f0cbb4-b614-475d-8f34-332b07fa6a45","Correction to: A systemic framework of energy efficiency in schools: experiences from six European countries (Energy Efficiency, (2023), 16, 4, (21), 10.1007/s12053-023-10099-4)","Brychkov, Dmitry (NUI Galway); Goggins, Gary (National University of Ireland Galway); Doherty, Edelle (National University of Ireland Galway); Romero Herrera, N.A. (TU Delft Design Conceptualization and Communication); Roudil, Nadine (National School of Architecture of Paris-Val de Seine, Paris); Di Trani, Antonella (National School of Architecture of Paris-Val de Seine, Paris); Singh, A. (TU Delft Design Conceptualization and Communication); Smit, S (R2M Solution, London); McLoughlin, Eilish (DCU)","","2023","The original version of the article does not contain information about the funding of the research. The text below can be added to the existing text in relation to funding. ENERGE is an Interreg North-West Europe (NWE) project, co-funded by the European Regional Development Fund Project Number NWE-827.","","en","journal article","","","","","","Funding Information: ENERGE is an Interreg North-West Europe (NWE) project, co-funded by the European Regional Development Fund Project Number NWE-827. Publisher Copyright: © The Author(s) 2023.","","","","","Design Conceptualization and Communication","","",""
"uuid:d84eea0b-625f-4f77-87e8-f7146b2625c1","http://resolver.tudelft.nl/uuid:d84eea0b-625f-4f77-87e8-f7146b2625c1","Circular Communities: The circular value flower as a design method for collectively closing resource flows","Leclercq, E.M. (TU Delft Design Aesthetics); Smit, M.J. (TU Delft Architectural Technology)","","2023","In Circular Communities, pioneering, collectively supported initiatives that are aimed at closing resource cycles at neighbourhood level take a central position. They are all examples of initiatives that contribute to the transition to a circular economy. For the analysis of these different circular initiatives, the researchers – urban designer Els Leclercq and architect Mo Smit - developed a unique method: the Circular Value Flower method. This method helps to organize the collective closing of resource cycles (bio and tech materials, energy, water and nutrients) on a neighbourhood scale and provides insight into the added value (social, ecological, aesthetic, cultural and economic) that can be realized within the built environment. Circular Communities offers inspiration and lessons for integral sustainable interventions at the scale of the neighbourhood and ties in with the new Dutch Environmental Planning Act, which explicitly offers room for citizen initiatives and local commissioning in the Netherlands.","circular economy; multiple value creation; co-production; spatial interventions; citizen engagement; integral approach; community design; neighbourhood design","en","book","TU Delft OPEN Publishing","978-94-6208-741-5","","","","","","","","","Design Aesthetics","","",""
"uuid:068bfef4-db56-4b00-bf42-d8d3a90b110d","http://resolver.tudelft.nl/uuid:068bfef4-db56-4b00-bf42-d8d3a90b110d","A systemic framework of energy efficiency in schools: experiences from six European countries","Brychkov, Dmitry (NUI Galway); Goggins, Gary (National University of Ireland Galway); Doherty, Edelle (National University of Ireland Galway); Romero Herrera, N.A. (TU Delft Design Conceptualization and Communication); Roudil, Nadine (National School of Architecture of Paris-Val de Seine, Paris); Di Trani, Antonella (National School of Architecture of Paris-Val de Seine, Paris); Singh, A. (TU Delft Design Conceptualization and Communication; TU Delft Industrial Design Engineering); Smit, Sander (R2M Solution, London); McLoughlin, Eilish (DCU)","","2023","Schools are complex physical and social institutions within national education systems. They account for significant energy consumption and like other buildings can demonstrate inefficient patterns of energy use. Poor energy performance of educational facilities is an intricate issue driven by complex causality of interconnected and dynamic factors. Addressing this issue requires a systemic approach, which is heretofore lacking. The aim of this research is to present and describe a systemic framework to facilitate energy reduction in schools across different European contexts. This transdisciplinary approach to sustainable energy use has been piloted in 13 post-primary schools located in six countries in northwest Europe. The research implements a series of planned activities and interventions, which help to unveil a systemic approach to improving energy efficiency in schools. The findings demonstrate how this approach, together with its ensuing methodologies and strategies, can contribute to reducing carbon emissions and improve knowledge and awareness around sustainable energy.","Collaboration; Digital transformation; Energy efficiency; Energy literacy; School; Systemic approach","en","journal article","","","","","","","","","Industrial Design Engineering","","Design Conceptualization and Communication","","",""
"uuid:d7d8c7ba-1dd0-48eb-a419-1c05def1f4df","http://resolver.tudelft.nl/uuid:d7d8c7ba-1dd0-48eb-a419-1c05def1f4df","Network dynamics and its impact on innovation outcomes: R&D consortia in the Dutch water sector","Mannak, Remco S. (Tilburg University); Markus, Arjan (Eindhoven University of Technology); Meeus, Marius T.H. (Tilburg University); Raab, Jörg (Tilburg University); Smit, A.C. (TU Delft Values Technology and Innovation; TU Delft Economics of Technology and Innovation)","","2023","In this study, we explore the relationship between inter-organizational network dynamics and innovation outcomes. We focus on node turnover and argue that both cluster and broker dynamics can range from low (stable) to high (volatile), resulting in differentiated outcomes. The data comprises 318 consortium members participating in 104 R&D consortia forged in a 23-year period in the Dutch water sector. Our analysis reveals two equifinal combinations (stable brokers – volatile clusters and volatile brokers – stable clusters) that both generate significantly higher innovation outcomes compared to networks with low, moderate, or high dynamics across the entire network.","Innovation; Network dynamics; Network structure; Node turnover; R&D consortia","en","journal article","","","","","","","","","","Values Technology and Innovation","Economics of Technology and Innovation","","",""
"uuid:b8eccbd6-9f31-472c-91db-453347e5434a","http://resolver.tudelft.nl/uuid:b8eccbd6-9f31-472c-91db-453347e5434a","Causal inference using observational intensive care unit data: a scoping review and recommendations for future practice","Smit, J.M. (TU Delft Pattern Recognition and Bioinformatics; Erasmus MC); Krijthe, J.H. (TU Delft Pattern Recognition and Bioinformatics); Kant, W. M.R. (Radboud Universiteit Nijmegen); Labrecque, J. A. (Erasmus MC); Komorowski, M. (Imperial College London; Charing Cross Hospital); Gommers, D.A.M.P.J. (Erasmus MC); van Bommel, J. (Erasmus MC); Reinders, M.J.T. (TU Delft Pattern Recognition and Bioinformatics); van Genderen, M. E. (Erasmus MC)","","2023","This scoping review focuses on the essential role of models for causal inference in shaping actionable artificial intelligence (AI) designed to aid clinicians in decision-making. The objective was to identify and evaluate the reporting quality of studies introducing models for causal inference in intensive care units (ICUs), and to provide recommendations to improve the future landscape of research practices in this domain. To achieve this, we searched various databases including Embase, MEDLINE ALL, Web of Science Core Collection, Google Scholar, medRxiv, bioRxiv, arXiv, and the ACM Digital Library. Studies involving models for causal inference addressing time-varying treatments in the adult ICU were reviewed. Data extraction encompassed the study settings and methodologies applied. Furthermore, we assessed reporting quality of target trial components (i.e., eligibility criteria, treatment strategies, follow-up period, outcome, and analysis plan) and main causal assumptions (i.e., conditional exchangeability, positivity, and consistency). Among the 2184 titles screened, 79 studies met the inclusion criteria. The methodologies used were G methods (61%) and reinforcement learning methods (39%). Studies considered both static (51%) and dynamic treatment regimes (49%). Only 30 (38%) of the studies reported all five target trial components, and only seven (9%) studies mentioned all three causal assumptions. To achieve actionable AI in the ICU, we advocate careful consideration of the causal question of interest, describing this research question as a target trial emulation, usage of appropriate causal inference methods, and acknowledgement (and examination of potential violations of) the causal assumptions.","","en","review","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:ba67aa42-eadf-48b9-8f24-8e3175e91639","http://resolver.tudelft.nl/uuid:ba67aa42-eadf-48b9-8f24-8e3175e91639","Conceptual design of compliant bone scaffolds by full-scale topology optimization","Smit, Thijs (ETH Zürich); Koppen, S. (TU Delft Computational Design and Mechanics); Ferguson, Stephen J. (ETH Zürich); Helgason, Benedikt (ETH Zürich)","","2023","A promising new treatment for large and complex bone defects is to implant specifically designed and additively manufactured synthetic bone scaffolds. Optimizing the scaffold design can potentially improve bone in-growth and prevent under- and over-loading of the adjacent tissue. This study aims to optimize synthetic bone scaffolds over multiple-length scales using the full-scale topology optimization approach, and to assess the effectiveness of this approach as an alternative to the currently used mono- and multi-scale optimization approaches for orthopaedic applications. We present a topology optimization formulation, which is matching the scaffold's mechanical properties to the surrounding tissue in compression. The scaffold's porous structure is tuneable to achieve the desired morphological properties to enhance bone in-growth. The proposed approach is demonstrated in-silico, using PEEK, cortical bone and titanium material properties in a 2D parameter study and on 3D designs. Full-scale topology optimization indicates a design improvement of 81% compared to the multi-scale approach. Furthermore, 3D designs for PEEK and titanium are additively manufactured to test the applicability of the method. With further development, the full-scale topology optimization approach is anticipated to offer a more effective alternative for optimizing orthopaedic structures compared to the currently used multi-scale methods.","Additive Manufacturing; Compliant bone scaffolds; Full-scale; High-resolution; Orthopaedic applications; Porous structures; Topology optimization","en","journal article","","","","","","","","","","","Computational Design and Mechanics","","",""
"uuid:26762693-e278-4757-8ed9-5038f878079c","http://resolver.tudelft.nl/uuid:26762693-e278-4757-8ed9-5038f878079c","Lactones from Unspecific Peroxygenase-Catalyzed In-Chain Hydroxylation of Saturated Fatty Acids","Ebrecht, Ana C. (University of the Free State); Mofokeng, Thato M. (University of the Free State); Hollmann, F. (TU Delft BT/Biocatalysis); Smit, Martha S. (University of the Free State); Opperman, Diederik J. (University of the Free State)","","2023","γ- and δ-lactones are valuable flavor and fragrance compounds. Their synthesis depends on the availability of suitable hydroxy fatty acid precursors. Three short unspecific peroxygenases were identified that selectively hydroxylate the C4 and C5 positions of C8-C12 fatty acids to yield after lactonization the corresponding γ- and δ-lactones. A preference for C4 over C5 hydroxylation gave γ-lactones as the major products. Overoxidation of the hydroxy fatty acids was addressed via the reduction of the resulting oxo acids using an alcohol dehydrogenase in a bienzymatic cascade reaction.","","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:df138b42-996d-4c9f-b181-bd4112dfb291","http://resolver.tudelft.nl/uuid:df138b42-996d-4c9f-b181-bd4112dfb291","A mild-slope formulation based on Weyl rule of association with application to coastal wave modelling","Akrish, G. (TU Delft Environmental Fluid Mechanics); Smit, Pieter (Sofar Ocean Technologies); Zijlema, Marcel (TU Delft Environmental Fluid Mechanics); Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics)","","2023","Weyl rule of association, proposed by Hermann Weyl for quantum mechanics applications (Weyl, 1931), can be used to associate between the dispersion relation of water waves and a non-local pseudo-differential operator. The central result of this study is that this operator correctly approximates the Dirichlet-to-Neumann operator derived for linear waves over a slowly varying bathymetry. This opens the door to a formal use of Weyl's operational calculus, and consequently, allowing straightforward derivations and generalizations of water waves’ models over mild slopes. Specifically, within the framework of linear wave theory, the formulation based on Weyl rule of association provides a generalized mild-slope model which does not impose a limit on the spectral width. Most significantly, the mild-slope formulation based on Weyl rule of association allows to derive a general linear kinetic equation for which the widely used energy balance equation (the central equation of forecasting models such as SWAN and WAVEWATCH) serves as a special case. This result not only provides a formal link between the deterministic description (i.e., Euler equations) and the stochastic description (i.e., the energy balance equation), but also establishes the theoretical foundations for the statistical description of bathymetry-induced wave interferences. Such a statistical description is especially important over coastal waters, where through the interaction with the bathymetry, waves are rapidly scattered and tend to form focal zones and associated interference patterns.","A mild-slope formulation; Phase-averaged models; Spectral modelling of coastal waves; Statistical wave interferences; The energy balance equation; Weyl rule of association","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:f1a153d9-5dff-4ef9-9029-00a815b4b43b","http://resolver.tudelft.nl/uuid:f1a153d9-5dff-4ef9-9029-00a815b4b43b","A typology for the university campus as a living lab for Facility Management education and research","van Tankeren, Wouter (Breda University of applied sciences); Danivska, Vitalija (Breda University of applied sciences); Smit, Bert (Breda University of applied sciences)","","2022","Background and aim - The university campus is a built environment facilitating activities centred around learning and knowledge development. This confluence of activities makes the university campus uniquely suited to bring together stakeholders and to generate meaningful experiences to not only learn about but also further develop the facilitation of such experiences in the Facility Management (FM) discipline. This study aims to lower thresholds for universities using their campus as an integral part of FM education and research. Originality - This paper introduces a typology for FM focused campus living labs (CLL) to help specify university administrators’ motives towards implementing living labs on campus. Methods / Methodology - A conceptual FM CLL typology was developed through literature review on living labs and adapted for use in a FM context. Results - Four types of FM CLL are suggested primarily based on the distinct purpose, the stakeholder mix, initiator role(s), and the desired/expected output: (1) Learning company for practical education, (2) Incubator for systems thinking, (3) Test lab as a R&D test bed, and (4) Innovation hub for knowledge development. Practical or social implications - This paper provides administrators of higher education institutions with FM related programmes a typology which can aid them in aligning organisation objectives with the specific purposes for using the campus as a living lab for FM education/innovation. In time, this can help administrators/educators to facilitate more active/experiential learning activities, while also providing researchers with opportunities to develop knowledge of FM (practices). Type of paper - Conceptual research paper (full).","Campus Living Lab; Facility Management; Living Lab; Higher Education","en","conference paper","","","","","","","","","","","","","",""
"uuid:d10a6b18-a90d-4936-999d-9c23a9a13f40","http://resolver.tudelft.nl/uuid:d10a6b18-a90d-4936-999d-9c23a9a13f40","Adaptive Incremental Nonlinear Dynamic Inversion Flight Control for Consistent Handling Qualities","Smit, B. (Student TU Delft); Pollack, T.S.C. (TU Delft Control & Simulation); van Kampen, E. (TU Delft Control & Simulation)","","2022","Control augmentation systems based on Incremental Nonlinear Dynamic Inversion (INDI) are able to provide high-performance nonlinear control without a holistic model. Considering an angular rate control law for a fixed-wing aircraft, only a control effectiveness (CE) model and angular acceleration measurement feedback is required. Despite enhanced robustness against parametric model mismatches due to reduced model dependency, the performance of INDI-based control laws can still vary due to inaccurate CE models. This paper confirms that longitudinal centre of gravity (CG) shifts and CE uncertainty result in varying handling qualities and stability (HQ\&S) characteristics. An adaptive solution using Least-Mean-Square (LMS) based parameter estimation is investigated to address these variations. The results demonstrate that online CE model correction result in reduced HQ\&S variation. However, it was found that some flight conditions together with adverse CG shifts could lead to violation of the time-scale separation assumption that underlies the adaptive control law design. As this assumption is inherent to the INDI control design itself as well, online CE model correction is only partly able to resolve the resulting performance variations.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:ed4b0862-87c0-4198-8638-6a3374f5bf09","http://resolver.tudelft.nl/uuid:ed4b0862-87c0-4198-8638-6a3374f5bf09","Real-World Testing of the Self Grasping Hand, a Novel Adjustable Passive Prosthesis: A Single Group Pilot Study","O’Brien, Lisa (Monash University; Swinburne University of Technology); Montesano, Elena (Caulfield Hospital); Chadwell, Alix (University of Salford); Kenney, Laurence (University of Salford); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2022","(1) Background: This study investigated the feasibility of conducting a two-week “real-world” trial of the Self Grasping Hand (SGH), a novel 3D printed passive adjustable prosthesis for hand absence; (2) Methods: Single-group pilot study of nine adults with trans-radial limb absence; five used body-powered split-hooks, and four had passive cosmetic hands as their usual prosthesis. Data from activity monitors were used to measure wear time and bilateral activity. At the end of the two-week trial, function and satisfaction were measured using the Orthotics and Prosthetics Users’ Survey Function Scale (OPUS) and the prosthesis satisfaction sub-scales of the Trinity Amputations and Prosthesis Experience Scale (TAPES). Semi-structured interviews captured consumer feedback and suggestions for improvement; (3) Results: Average SGH wear time over 2 weeks was 17.5 h (10% of total prosthesis wear time) for split-hook users and 83.5 h (63% of total prosthesis wear time) for cosmetic hand users. Mean satisfaction was 5.2/10, and mean function score was 47.9/100; (4) Two-week real-world consumer testing of the SGH is feasible using the methods described. Future SGH designs need to be more robust with easier grasp lock/unlock.","prosthetic; passive; adjustable; hand; 3D printing; trans-radial","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:75c1a0f0-152e-4765-8095-a0da39966a6e","http://resolver.tudelft.nl/uuid:75c1a0f0-152e-4765-8095-a0da39966a6e","State of the art of prosthesis simulators for the upper limb: A narrative review","Sinke, Maaike (Student TU Delft); Chadwell, Alix (University of Salford); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2022","Background: Research into prosthesis training and design puts a burden on the small population of people with upper-limb absence who can participate in these studies. One solution is to use a prosthetic hand simulator, which allows for attaching a hand prosthesis to an intact limb. However, whether the results of prosthesis simulator studies can be translated to people with upper-limb absence using a hand prosthesis is unclear. Objective: To review the literature on prosthetic hand simulators, provide an overview of current designs, and highlight the differences and similarities between prosthesis simulators and traditional prostheses. Methods: A Boolean combination of keywords was used to search 3 electronic databases: PubMed, Scopus and Web of Science. Relevant articles in English were selected. Results: In total, 52 papers were included in the review, and an overview of the state of the art was presented. We identified the key differences between prosthesis simulators and traditional prostheses as the position of the terminal device and the available degrees of freedom of the arm and (prosthetic) wrist. Conclusions: This paper provides an overview of prosthesis simulator designs over the past 27 years and an overview of the similarities and differences between prosthesis simulators and prostheses. The literature does not provide enough evidence to establish whether the results obtained from simulator studies could be translated to prostheses. A recommendation for future simulator design is to constrain pro- and supination of the forearm of anatomically intact participants and add a prosthetic wrist that can pro- and supinate. Additional research is required to find the ideal terminal device position for a prosthesis simulator with respect to the person's hand.","Bypass prosthesis; Hand prostheses; Prosthesis simulator; Upper limb","en","review","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:0782fd6a-85e4-40cf-a099-8b4b654dff82","http://resolver.tudelft.nl/uuid:0782fd6a-85e4-40cf-a099-8b4b654dff82","Integrating technology, education and practice to change energy behaviours in schools","Doherty, Edelle (National University of Ireland Galway); Brychkov, Dmitry (National University of Ireland Galway); Romero Herrera, N.A. (TU Delft Design Conceptualization and Communication); McLoughlin, Eilish (Dublin City University); Roudil, Nadine (École Nationale Supérieure d’Architecture de Paris Val de Seine); Smit, Sander (R2M Solution, London); Maas, Stefan (University of Luxembourg); Gauthier, Florence (Regional Council of Center-Val de Loire); Clifford, Eoghan (National University of Ireland Galway); Delmonte, Branca Arthur (University of Luxembourg)","","2022","Schools are learning communities where multiple stakeholders can collaborate to learn about energy efficiency, including via formal curricula, non-formal learning and day-to-day practices. Furthermore, by improving energy literacy among building occupants, the energy efficiency of schools can be improved. However, turning schools into learning communities rather than learning organizations is still problematic. This article details a case study realised in the form of the ENERGE project, which integrates technological, educational and practical activities in 13 post-primary schools from 6 European countries. Owing to an extensive collaboration of diverse stakeholders, the ENERGE project resulted in the origination of a learning community around energy efficiency in the schools. The outcomes of building a learning community within the ENERGE project included: capacity building (in the form of the ENERGE Committees and Teacher Network), the introduction of digital education (via the ENERGE digital platform), development of curriculum-based modules to raise energy literacy, and the establishment of a viable model for expanding ENERGE experience to other schools. The article concludes by explaining the benefits of the ENERGE approach for stakeholders.","Business model; energy; energy literacy; digital platform; learning community","en","conference paper","TU Delft OPEN Publishing","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:6f8d456f-d279-4824-8c43-b3ac84e39dde","http://resolver.tudelft.nl/uuid:6f8d456f-d279-4824-8c43-b3ac84e39dde","Comparison of two cable configurations in 3D printed steerable instruments for minimally invasive surgery","Culmone, C. (TU Delft Medical Instruments & Bio-Inspired Technology); van Starkenburg, R.I.B. (TU Delft EMSD EEMCS Project technicians); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2022","In laparoscopy, a small incision size improves the surgical outcome but increases at the same time the rigidity of the instrument, with consequent impairment of the surgeon’s maneuverability. Such reduction introduces new challenges, such as the loss of wrist articulation or the impossibility of overcoming obstacles. A possible approach is using multi-steerable cable-driven instruments fully mechanical actuated, which allow great maneuverability while keeping the wound small. In this work, we compared the usability of the two most promising cable configurations in 3D printed multi-steerable instruments: a parallel configuration with all cables running straight from the steerable shaft to the handle; and a multi configuration with straight cables in combination with helical cables. Twelve participants were divided into two groups and asked to orient the instrument shaft and randomly hit six targets following the instructions in a laparoscopic simulator. Each participant carried out four trials (two trials for each instrument) with 12 runs per trial. The average task performance time showed a significant decrease over the first trial for both configurations. The decrease was 48% for the parallel and 41% for the multi configuration. Improvement of task performance times reached a plateau in the second trial with both instruments. The participants filled out a TLX questionnaire after each trial. The questionnaire showed a lower burden score for the parallel compared to multi configuration (23% VS 30%). Even though the task performance time for both configurations was comparable, a final questionnaire showed that 10 out of 12 participants preferred the parallel configuration due to a more intuitive hand movement and the possibility of individually orienting the distal end of the steerable shaft","","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:a846b380-e498-45c6-af55-cae3900236cd","http://resolver.tudelft.nl/uuid:a846b380-e498-45c6-af55-cae3900236cd","Processing of Fibre Reinforced Polymers by Controlled Radical Induced Cationic Frontal Polymerisation","Staal, Jeroen (Swiss Federal Institute of Technology); Smit, Edgar (Swiss Federal Institute of Technology); Caglar, Baris (TU Delft Aerospace Manufacturing Technologies); Michaud, Véronique (Swiss Federal Institute of Technology)","Vassilopoulos, Anastasios P. (editor); Michaud, Véronique (editor)","2022","Radical Induced Cationic Frontal Polymerisation (RICFP) has recently been proposed as a promising strategy for processing of epoxide carbon fibre reinforced polymers. Control of the local heat balance is crucial towards the production of industrial-quality composites, which is typically achieved via controlling the heat generation. In this work we present a comprehensive overview of RICFP processing of cycloaliphatic epoxide composites with enhance heat insulation. The thermal initiating compound was identified as the main component to control heat generation, which correlated well with the front velocity. A processing window was defined as function of the fibre and initiator contents and composites with to 45.8% Vf were successfully produced. Optimisation of resulting mechanical properties was made possible by optimisation of the heat balance, with matrix glass transition temperatures of up to 187°C achieved for the used cycloaliphatic system. Post-curing was found beneficial to overcome suggested inhomogeneous curing due to the dual-scale nature of fabrics.","frontal polymerization; composite processing; fibre reinforced polymer composite","en","conference paper","EPFL Lausanne, Composite Construction Laboratory","","","","","","","","","","Aerospace Manufacturing Technologies","","",""
"uuid:640f0875-681e-479b-a309-687689f946e7","http://resolver.tudelft.nl/uuid:640f0875-681e-479b-a309-687689f946e7","Energy Citizenship in Positive Energy Districts— Towards a Transdisciplinary Approach to Impact Assessment","van Wees, Mark (Hogeschool van Amsterdam); Revilla, Beatriz Pineda (Hogeschool van Amsterdam); Fitzgerald, Helena (University of Limerick); Ahlers, Dirk (Norwegian University of Science and Technology (NTNU)); Romero Herrera, N.A. (TU Delft Design Conceptualization and Communication); Alpagut, Beril (Demir Energy, Istanbul); Kort, Joke (TNO Energy Transition); Tjahja, Cyril (Hanze Hogeschool Groningen); Smit, Sander (R2M Solution, London)","","2022","It is commonly assumed by the projects demonstrating concepts for positive energy districts in cities across Europe that citizens want and need to be involved in the development of these concepts as an essential condition for positive energy districts to be deployed successfully and to achieve the expected societal goals. Six different research and innovation projects are investigating the different forms of energy citizenship in positive energy districts and their impacts. They aim to apply a transdisciplinary approach to collaborative research and to impact assessment. The interim results are described, and preliminary conclusions on impact are drawn. The projects each used different approaches to engaging citizens, while differentiating between different groups. Progress is monitored but only fragmentary evidence on the impact has been gathered. Transdisciplinary approaches are being developed but are still immature.","Citizen engagement; Energy citizenship; Energy transition; Impact assessment; Multidisciplinary; PED; Positive energy districts; Transdisciplinary","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:406ac393-568b-4521-b983-8736478b7af5","http://resolver.tudelft.nl/uuid:406ac393-568b-4521-b983-8736478b7af5","Discrete and metric divisorial gonality can be different","van Dobben de Bruyn, J. (TU Delft Discrete Mathematics and Optimization); Smit, Harry (Max Planck Institute for Mathematics); van der Wegen, Marieke (Universiteit Utrecht)","","2022","This paper compares the divisorial gonality of a finite graph G to the divisorial gonality of the associated metric graph Γ(G,1) with unit lengths. We show that dgon(Γ(G,1)) is equal to the minimal divisorial gonality of all regular subdivisions of G, and we provide a class of graphs for which this number is strictly smaller than the divisorial gonality of G. This settles a conjecture of M. Baker [3, Conjecture 3.14] in the negative.","Chip-firing game; Finite graph; Gonality; Metric graph","en","journal article","","","","","","","","","","","Discrete Mathematics and Optimization","","",""
"uuid:b0e01a9f-0418-4072-9ed1-5fe3f4450844","http://resolver.tudelft.nl/uuid:b0e01a9f-0418-4072-9ed1-5fe3f4450844","Improving MFI-UF constant flux to more accurately predict particulate fouling in RO systems: Quantifying the effect of membrane surface porosity","Abunada, M.B.M. (TU Delft Sanitary Engineering; IHE Delft Institute for Water Education); Dhakal, N. (TU Delft Sanitary Engineering; IHE Delft Institute for Water Education); Andyar, William Z. (IHE Delft Institute for Water Education); Ajok, Pamela (IHE Delft Institute for Water Education); Smit, Herman (PWN Drinking Water Supply Company); Ghaffour, Noreddine (King Abdullah University of Science and Technology); Schippers, Jan C. (IHE Delft Institute for Water Education); Kennedy, M.D. (TU Delft Sanitary Engineering; IHE Delft Institute for Water Education)","","2022","This study aimed to quantify the effect of membrane surface porosity on particulate fouling predicted by the MFI-UF method at constant flux. Firstly, the surface porosity of polyethersulfone UF membranes (5–100 kDa) was determined using ultra-high resolution SEM. Thereafter, the MFI-UF was measured using suspensions of polystyrene particles (75 nm), which were pre-washed to remove surfactant and particle fractions smaller than the pores of MFI-UF membranes, thus ensuring complete retention of particles during MFI-UF measurements. Consequently, the MFI-UF values of washed polystyrene particle suspensions were independent of the pore size and depended only on the surface porosity of MFI-UF membrane. The results showed that the membrane surface porosity decreased with MWCO from 10.5% (100 kDa) to 0.6% (5 kDa), and consequently the MFI-UF increased from 3700 to 8700 s/L2, respectively. This increase in MFI-UF was attributed to the non-uniform distribution of membrane pores, which is exacerbated as surface porosity decreases. Consequently, preliminary correction factors of 0.4–1.0 were proposed for MFI-UF measured with UF membranes in the range 5–100 kDa. Finally, the surface porosity correction was applied to predict particulate fouling in a full-scale RO plant. However, additional research is required to establish correction factors for different types of feed water.","Cake filtration; Membrane surface porosity; MFI-UF; Particulate fouling; Washed polystyrene particles","en","journal article","","","","","","","","","","","Sanitary Engineering","","",""
"uuid:32b270bb-e985-46fb-896e-22efd812136f","http://resolver.tudelft.nl/uuid:32b270bb-e985-46fb-896e-22efd812136f","Dynamic prediction of mortality in COVID-19 patients in the intensive care unit: A retrospective multi-center cohort study","Smit, J.M. (TU Delft Pattern Recognition and Bioinformatics; Erasmus MC); Krijthe, J.H. (TU Delft Pattern Recognition and Bioinformatics); Gommers, D.A.M.P.J. (Erasmus MC); Kamps, M. J.A. (Catharina Hospital); Cornet, A.J. (TU Delft Team Arjan Mol; Erasmus MC); Arbous, M. S. (Erasmus MC; Catharina Ziekenhuis); De Bruin, D. P. (Erasmus MC; Elisabeth-TweeSteden Ziekenhuis); Van Bommel, J. (Erasmus MC); Reinders, M.J.T. (TU Delft Pattern Recognition and Bioinformatics)","","2022","Background: The COVID-19 pandemic continues to overwhelm intensive care units (ICUs) worldwide, and improved prediction of mortality among COVID-19 patients could assist decision making in the ICU setting. In this work, we report on the development and validation of a dynamic mortality model specifically for critically ill COVID-19 patients and discuss its potential utility in the ICU. Methods: We collected electronic medical record (EMR) data from 3222 ICU admissions with a COVID-19 infection from 25 different ICUs in the Netherlands. We extracted daily observations of each patient and fitted both a linear (logistic regression) and non-linear (random forest) model to predict mortality within 24 h from the moment of prediction. Isotonic regression was used to re-calibrate the predictions of the fitted models. We evaluated the models in a leave-one-ICU-out (LOIO) cross-validation procedure. Results: The logistic regression and random forest model yielded an area under the receiver operating characteristic curve of 0.87 [0.85; 0.88] and 0.86 [0.84; 0.88], respectively. The recalibrated model predictions showed a calibration intercept of −0.04 [−0.12; 0.04] and slope of 0.90 [0.85; 0.95] for logistic regression model and a calibration intercept of −0.19 [−0.27; −0.10] and slope of 0.89 [0.84; 0.94] for the random forest model. Discussion: We presented a model for dynamic mortality prediction, specifically for critically ill COVID-19 patients, which predicts near-term mortality rather than in-ICU mortality. The potential clinical utility of dynamic mortality models such as benchmarking, improving resource allocation and informing family members, as well as the development of models with more causal structure, should be topics for future research.","","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:8ff92af8-b412-4f21-b800-0a180a630144","http://resolver.tudelft.nl/uuid:8ff92af8-b412-4f21-b800-0a180a630144","Development and validation of an early warning model for hospitalized COVID-19 patients: a multi-center retrospective cohort study","Smit, J.M. (TU Delft Pattern Recognition and Bioinformatics; Erasmus MC); Krijthe, J.H. (TU Delft Pattern Recognition and Bioinformatics); Tintu, Andrei N. (Erasmus MC); Endeman, Henrik (Erasmus MC); Ludikhuize, Jeroen (HagaZiekenhuis; Amsterdam UMC); van Genderen, Michel E. (Erasmus MC); Gommers, D.A.M.P.J. (Erasmus MC); Arbous, M.S. (Leiden University Medical Center); Reinders, M.J.T. (TU Delft Pattern Recognition and Bioinformatics)","","2022","Background: Timely identification of deteriorating COVID-19 patients is needed to guide changes in clinical management and admission to intensive care units (ICUs). There is significant concern that widely used Early warning scores (EWSs) underestimate illness severity in COVID-19 patients and therefore, we developed an early warning model specifically for COVID-19 patients. Methods: We retrospectively collected electronic medical record data to extract predictors and used these to fit a random forest model. To simulate the situation in which the model would have been developed after the first and implemented during the second COVID-19 ‘wave’ in the Netherlands, we performed a temporal validation by splitting all included patients into groups admitted before and after August 1, 2020. Furthermore, we propose a method for dynamic model updating to retain model performance over time. We evaluated model discrimination and calibration, performed a decision curve analysis, and quantified the importance of predictors using SHapley Additive exPlanations values. Results: We included 3514 COVID-19 patient admissions from six Dutch hospitals between February 2020 and May 2021, and included a total of 18 predictors for model fitting. The model showed a higher discriminative performance in terms of partial area under the receiver operating characteristic curve (0.82 [0.80–0.84]) compared to the National early warning score (0.72 [0.69–0.74]) and the Modified early warning score (0.67 [0.65–0.69]), a greater net benefit over a range of clinically relevant model thresholds, and relatively good calibration (intercept = 0.03 [− 0.09 to 0.14], slope = 0.79 [0.73–0.86]). Conclusions: This study shows the potential benefit of moving from early warning models for the general inpatient population to models for specific patient groups. Further (independent) validation of the model is needed.","Artificial intelligence; COVID-19; Dynamic model updating; Early warning score; Intensive care; Machine learning; Medical prediction model","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:1faa189a-ac35-497f-ba61-d88df68b885a","http://resolver.tudelft.nl/uuid:1faa189a-ac35-497f-ba61-d88df68b885a","A nonlinear, non-dispersive energy balance for surfzone waves: Infragravity wave dynamics on a sloping beach","Rijnsdorp, D.P. (TU Delft Environmental Fluid Mechanics); Smit, Pieter B. (Sofar Ocean Technologies); Guza, R. T. (Scripps Institution of Oceanography)","","2022","A fully nonlinear non-dispersive energy balance for surfzone waves is derived based on the nonlinear shallow water equations to study the nearshore dynamics of infragravity (IG) waves. Based on simulations of waves on a relatively moderate and mild beach slope with a non-hydrostatic wave-flow model (SWASH), the new theory shows that spatial gradients in IG energy flux are nearly completely balanced by the combined effect of bottom stresses and predominantly nonlinear triad interactions. The new balance confirms many features of existing weakly nonlinear theories, and yields an improved description in the inner surfzone where waves become highly nonlinear. A gain of IG energy flux throughout the shoaling and outer surfzones is driven by triad interactions between IG waves and pairs of sea-swell (SS) waves. The IG energy flux decreased in the inner surfzone, primarily through an energy cascade to the swell-band and superharmonic frequencies where wave energy is ultimately dissipated. Dissipation by bottom friction was weak on both slopes. The IG wave breaking, characterized by triads between three IG or two IG waves and one SS wave, was significant only deep inside the surfzone of the mild slope. Even though IG waves broke on the mild slope, nonlinear interactions between IG waves and pairs of SS waves were responsible for at least half of the net IG flux loss.","surface gravity waves; wave breaking; wind-wave interactions","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:abb1176c-55fa-494b-9cf3-3f981f6b502c","http://resolver.tudelft.nl/uuid:abb1176c-55fa-494b-9cf3-3f981f6b502c","Making Access: Increasing Inclusiveness in Making","Fuchsberger, Verena (University of Salzburg); Smit, Dorothé (University of Salzburg); Campreguer França, Nathalia (University of Salzburg); Regal, Georg (AIT Austrian Institute of Technology); Wuschitz, Stefanie (Mz Baltazar’s Laboratory Vienna,); Huber, Barbara (Mz Baltazar’s Laboratory Vienna,); Kowolik, Joanna (Happylab, Vienna); Devendorf, Laura (University of Colorado); Giaccardi, Elisa (TU Delft Human Information Communication Design); Trotto, Ambra (Umeå University)","","2022","In this one-day workshop we are going to make access. We aim to counteract the phenomenon that access to making (e.g., in makerspaces, fablabs, etc.) is not equally distributed, with certain groups of people being underrepresented (e.g., women∗1). After brief introductions from participants and a set of three impulse keynotes, we will envision and ""make""interventions together, such as speculative or provocative objects and actions. The workshop takes a constructive stance with the goal to not rest on empirical and theoretical findings or individual experiences, but to translate those into viable interventions. These serve as exemplars of findings with the clear goal of being deployed soon after.","age; cultures; diversity; feminism; gender identities; inclusion; intersectionality; makerspaces; making; normcreativity","en","conference paper","Association for Computing Machinery (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.","","2022-10-28","","","Human Information Communication Design","","",""
"uuid:32227ce7-6cf4-4035-84fe-2d5025cc34e1","http://resolver.tudelft.nl/uuid:32227ce7-6cf4-4035-84fe-2d5025cc34e1","Towards an Active Predictive Relation by Reconceptualizing a Vacuum Robot: Research on the Transparency and Acceptance of the Predictive Behaviors","Guo, Peicheng (Student TU Delft); Smit, I.R. (TU Delft Human Information Communication Design)","Kurosu, Masaaki (editor); Yamamoto, Sakae (editor); Mori, Hirohiko (editor); Schmorrow, Dylan D. (editor); Fidopiastis, Cali M. (editor); Streitz, Norbert A. (editor); Konomi, Shin’ichi (editor)","2022","With the development of Artificial intelligence, the connected objects are extended with the predictive capabilities and the character of things can change to “things that predict”. If a connected device is able to embrace a predictive system that not only profiles for scripted behavior but could also use the knowledge co-created by all the other similar devices and their users that encounter similar situations, the predictions can be generated based on that. In this case, a new type of interplay between humans and things called “predictive relation” is created. However, before this future takes place, it is required to find out appropriate patterns to address challenges such as the transparency and users’ acceptance of predictive behaviors of connected products. The research in this article takes a vacuum robot as a reference product for the study. The research starts by collecting users’ daily practice with vacuum robots through 4-day diary booklets. And then the booklets serve as sensitizing tools to envision the possible predictive capabilities and lead the discussion on the acceptance and transparency of general predicting things. From the creative sessions we propose 1) design qualities for the acceptance of the predicting things, and 2) a model of generating predictive behavior that enhances the transparency. Eventually, we also propose the idea of “Designers as the facilitators of the human-robot collaboration”.","Acceptance; Artificial intelligence; Human-robot interaction; Internet of Things; Robot autonomy; Transparency","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.","","2023-07-01","","","Human Information Communication Design","","",""
"uuid:005aa783-2d4b-42a4-82ec-77c19519ecfa","http://resolver.tudelft.nl/uuid:005aa783-2d4b-42a4-82ec-77c19519ecfa","Demystifying machine learning for mortality prediction","Smit, J. M. (Student TU Delft; Erasmus MC); van Genderen, M. E. (Erasmus MC); Reinders, M.J.T. (TU Delft Pattern Recognition and Bioinformatics); Gommers, D. A.M.P.J. (Erasmus MC); Krijthe, J.H. (TU Delft Pattern Recognition and Bioinformatics); Van Bommel, J. (Erasmus MC)","","2021","","","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:c9d631b3-b670-4bcd-8c28-12ee53d8af29","http://resolver.tudelft.nl/uuid:c9d631b3-b670-4bcd-8c28-12ee53d8af29","Fast relative sensor orientation estimation in the presence of real-world disturbances","Remmerswaal, Evan (Student TU Delft); Weygers, Ive (Katholieke Universiteit Leuven); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Kok, M. (TU Delft Team Manon Kok)","","2021","We present a novel approach to estimate the relative sensor orientation from inertial sensors placed on connected body segments. Drift in the relative orientation estimates obtained by integrating the gyroscope measurements is corrected solely by incorporating common information in the inertial sensor measurements due to the connection of the body segments. We solve the estimation problem using a complementary filtering implementation to reduce the computational complexity. We study its robustness under common real-world model violations, e.g., soft tissue artifacts and spikes in the acceleration signals due to impacts. The efficacy of the method is illustrated with numerical simulations and is compared to a multiplicative extended Kalman filter implementation, both with and without outlier rejection. In addition, a human experiment strengthened the simulation results under realistic sensor errors.","","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.","","2022-07-03","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:8a1fc092-6604-48c1-9fef-28e2afd25511","http://resolver.tudelft.nl/uuid:8a1fc092-6604-48c1-9fef-28e2afd25511","The Stumblemeter: Design and Validation of a System That Detects and Classifies Stumbles during Gait","den Hartog, D.D.G. (Student TU Delft); Harlaar, J. (TU Delft Biomechatronics & Human-Machine Control; Erasmus MC); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2021","Stumbling during gait is commonly encountered in patients who suffer from mild to serious walking problems, e.g., after stroke, in osteoarthritis, or amputees using a lower leg prosthesis. Instead of self-reporting, an objective assessment of the number of stumbles in daily life would inform clinicians more accurately and enable the evaluation of treatments that aim to achieve a safer walking pattern. An easy-to-use wearable might fulfill this need. The goal of the present study was to investigate whether a single inertial measurement unit (IMU) placed at the shank and machine learning algorithms could be used to detect and classify stumbling events in a dataset comprising of a wide variety of daily movements. Ten healthy test subjects were deliberately tripped by an unexpected and unseen obstacle while walking on a treadmill. The subjects stumbled a total of 276 times, both using an elevating recovery strategy and a lowering recovery strategy. Subjects also performed multiple Activities of Daily Living. During data processing, an event-defined window segmentation technique was used to trace high peaks in acceleration that could potentially be stumbles. In the reduced dataset, time windows were labelled with the aid of video annotation. Subsequently, discriminative features were extracted and fed to train seven different types of machine learning algorithms. Trained machine learning algorithms were validated using leave-one-subject-out cross-validation. Support Vector Machine (SVM) algorithms were most successful, and could detect and classify stumbles with 100% sensitivity, 100% specificity, and 96.7% accuracy in the independent testing dataset. The SVM algorithms were implemented in a user-friendly, freely available, stumble detection app named Stumblemeter. This work shows that stumble detection and classification based on SVM is accurate and ready to apply in clinical practice","stumbling; detection; machine learning; inertial measurement unit; accelerometer; gyroscope; amputee; osseointegration","en","journal article","","","","","","","","","","","Biomechatronics & Human-Machine Control","","",""
"uuid:1c16d874-1615-4f6d-8ed2-c4591012ae3f","http://resolver.tudelft.nl/uuid:1c16d874-1615-4f6d-8ed2-c4591012ae3f","Waardevolle wijken: Het creëren van waarde in wijken door het gezamenlijk sluiten van grondstofkringlopen","Leclercq, E.M. (TU Delft Design & Construction Management); Smit, M.J. (TU Delft Architectural Engineering)","","2021","De circulaire transitie wordt vaak gepresenteerd als uitsluitend een technologische opgave, maar deze raakt tegelijkertijd aan sociale, organisatorische en institutionele vraagstukken, die veel vragen oproepen over ontwerpprocessen, benodigde kennis en kunde, verantwoordelijkheid en taakverdeling. Het sluiten van de verschillende grondstofkringlopen op lokaal niveau heeft de potentie om veel waarde toe te voegen aan de gebouwde omgeving, maar valt of staat met een systemische aanpak, dat wil zeggen dat oplossingen in samenhang worden benaderd en meegenomen zoals binnen een natuurlijk eco-systeem. Alleen dan kan de beoogde transitie plaatsvinden. Er wordt hierbij uitgegaan van burgers die zelf kennis hebben of kunnen ontwikkelen om hun eigen handelen te beïnvloeden, en dus zo hun handelingsperspectieven kunnen aanpassen. Bovendien vraagt een dergelijke ingrijpende transitie tevens om een andere organisatie van de bijbehorende ontwerp- en ontwikkelprocessen. Naast wet- en regelgeving op (inter)nationaal niveau zullen lokale, collectieve organisatievormen, waarbij een grotere en actievere rol is weggelegd voor burgers en ondernemers, onontbeerlijk zijn. De nieuwe Omgevingswet (die in 2022 waarschijnlijk intreedt) biedt hier ruimte aan.
De centrale vraag van dit onderzoek naar Waardevolle Wijken is dan ook hoe gemeenschappen door het zo lokaal mogelijk sluiten van grondstofkringlopen meerwaarde kunnen creëren in hun wijk. Het sluiten van de grondstofkringlopen vormt dus het startpunt van het onderzoek, maar hiernaast worden de betrokken actoren, hun ambities en de impact op de fysieke leefruimte meegenomen in de analyse. Voor deze onderzoeksthema’s is binnen dit onderzoek de Waardebloemmethode ontwikkeld, aan de hand waarvan zes circulaire gebiedsinitiatieven worden onderzocht.","","nl","report","Delft University of Technology","","","","","","","","","","Design & Construction Management","","",""
"uuid:310a7c29-12b4-40d6-a860-667af936fb15","http://resolver.tudelft.nl/uuid:310a7c29-12b4-40d6-a860-667af936fb15","Designing for calibrated trust: Exploring the challenges in calibrating trust between users and autonomous vehicles","Valentine, David Callisto (Student TU Delft); Smit, I.R. (TU Delft Human Information Communication Design); Kim, E.D.H.","","2021","Trust is an important factor in building acceptance of autonomous vehicles within our society, but the complex nature of trust makes it challenging to design for an appropriate level of trust. This can lead to instances of mistrust and/or distrust between users and AV’s. Designing for calibrated trust is a possible option to address this challenge. Existing research on designing for calibrated trust focuses on the human machine interaction (HMI), while from literature we infer that trust creation beings much before the first interaction between a user and an AV. The goal of our research is to broaden the scope of calibrated trust, by exploring the pre-use phase and understand the challenges faced in calibration of trust. Within our study 16 mobility experts were interviewed and a thematic analysis of the interviews was conducted. The analysis revealed the lack of clear communication between stakeholders, a solutionism approach towards designing and lack of transparency in design as the prominent challenges. Building on the research insights, we briefly introduce the Calibrated Trust Toolkit as our design solution, and conclude by proposing a sweet spot for achieving calibration of trust between users and autonomous vehicles.","AI Solutionism; Artificial intelligence; Calibrated Trust; Communication; Design to X","en","journal article","","","","","","","","","","","Human Information Communication Design","","",""
"uuid:2b3ea9db-b36f-42fe-b272-1bc62fce5475","http://resolver.tudelft.nl/uuid:2b3ea9db-b36f-42fe-b272-1bc62fce5475","Creating 3d indoor first responder situation awareness in real-time through a head-mounted ar device","Smit, Bart Peter (CGI); Voûte, R.L. (TU Delft GIS Technologie; CGI); Verbree, E. (TU Delft GIS Technologie)","","2021","Emergency operations are a key example for the need of digital twins in the way it is complex, urgent and uncertain. First, the process is complex, as many organizations are involved. Second, it is urgent, as most damage is done in the first moments of an emergency. Third, it is uncertain, as situational conditions tend to change quickly. For outdoor operations, spatial information systems help in creating an overview of the situation, for example by displaying positions of first responder units involved with the incident. However, spatial data of indoor environments is scarce. Static information of the building, such as floor plans, are often outdated or non-existent. Dynamic operational data such as positions of first responders within the building are only available in a very limited way as well, and often without visual representation. To create situation awareness of indoor first responder operation environments, this paper successfully proposes a proof of concept with two objectives. First, the proof of concept will collect spatial environment data in the form of mapping and tracking data by using a Microsoft HoloLens. This means the geometry of the building will be collected, together with traversed routes within the building. Second, the data will be streamed and displayed to a remote first responder coordinator in real-time to create a common operational picture. This enables the coordinator to quickly build situation awareness of the operation environment, enabling the coordinator to improve the quality of decisions, thereby improving first responder performance. The proof of concept showed that situation awareness on all three levels increases with the real-time (live) availability (visualisations) of 3D indoor environments. This concept needs to be tested further on usability and performance.","Digital Twins; First Responder; HoloLens; Indoor; Mapping; Real-Time; Situation Awareness; Tracking","en","journal article","","","","","","","","","","","GIS Technologie","","",""
"uuid:4bdf4335-65bd-4438-952e-5b55abd81fb3","http://resolver.tudelft.nl/uuid:4bdf4335-65bd-4438-952e-5b55abd81fb3","A Fully 3D-Printed Steerable Instrument for Minimally Invasive Surgery","Culmone, C. (TU Delft Medical Instruments & Bio-Inspired Technology); Lussenburg, K.M. (TU Delft Medical Instruments & Bio-Inspired Technology); Alkemade, J.P.E. (Student TU Delft); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Sakes, A. (TU Delft Medical Instruments & Bio-Inspired Technology); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2021","In the field of medical instruments, additive manufacturing allows for a drastic reduction in the number of components while improving the functionalities of the final design. In addition, modifications for users’ needs or specific procedures become possible by enabling the production of single customized items. In this work, we present the design of a new fully 3D-printed handheld steerable instrument for laparoscopic surgery, which was mechanically actuated using cables. The pistol-grip handle is based on ergonomic principles and allows for single-hand control of both grasping and omnidirectional steering, while compliant joints and snap-fit connectors enable fast assembly and minimal part count. Additive manufacturing allows for personalization of the handle to each surgeon’s needs by adjusting specific dimensions in the CAD model, which increases the user’s comfort during surgery. Testing showed that the forces on the instrument handle required for steering and grasping were below 15 N, while the grasping force efficiency was calculated to be 10–30%. The instrument combines the advantages of additive manufacturing with regard to personalization and simplified assembly, illustrating a new approach to the design of advanced surgical instruments where the customization for a single procedure or user’s need is a central aspect.","additive manufacturing; non-assembly; surgical instruments; ergonomics","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:2053b579-a663-4def-ad25-4bedad0169be","http://resolver.tudelft.nl/uuid:2053b579-a663-4def-ad25-4bedad0169be","PEBL: Pessimistic Ensembles for Offline Deep Reinforcement Learning","Smit, Jordi (Student TU Delft); Ponnambalam, C.T. (TU Delft Algorithmics); Spaan, M.T.J. (TU Delft Algorithmics); Oliehoek, F.A. (TU Delft Interactive Intelligence)","","2021","Offline reinforcement learning (RL), or learning from a fixed data set, is an attractive alternative to online RL. Offline RL promises to address the cost and safety implications of tak- ing numerous random or bad actions online, a crucial aspect of traditional RL that makes it difficult to apply in real-world problems. However, when RL is na ̈ıvely applied to a fixed data set, the resulting policy may exhibit poor performance in the real environment. This happens due to over-estimation of the value of state-action pairs not sufficiently covered by the data set. A promising way to avoid this is by applying pessimism and acting according to a lower bound estimate on the value. It has been shown that penalizing the learned value according to a pessimistic bound on the uncertainty can drastically improve offline RL. In deep reinforcement learn- ing, however, uncertainty estimation is highly non-trivial and development of effective uncertainty-based pessimistic algo- rithms remains an open question. This paper introduces two novel offline deep RL methods built on Double Deep Q- Learning and Soft Actor-Critic. We show how a multi-headed bootstrap approach to uncertainty estimation is used to cal- culate an effective pessimistic value penalty. Our approach is applied to benchmark offline deep RL domains, where we demonstrate that our methods can often beat the current state- of-the-art.","","en","conference paper","","","","","","","","","","","Algorithmics","","",""
"uuid:d012f892-360b-4b37-b834-2c7cd0168a57","http://resolver.tudelft.nl/uuid:d012f892-360b-4b37-b834-2c7cd0168a57","An evaluation of contralateral hand involvement in the operation of the Delft Self-Grasping Hand, an adjustable passive prosthesis","Chadwell, Alix (University of Salford); Chinn, Natalie (University of Salford); Kenney, Laurence (University of Salford); Karthaus, Zoë J. (Student TU Delft); Mos, Daniek (Student TU Delft); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2021","The Delft Self-Grasping Hand is an adjustable passive prosthesis operated using the concept of tenodesis (where opening and closing of the hand is mechanically linked to the flexion and extension of the wrist). As a purely mechanical device that does not require harnessing, the Self-Grasping Hand offers a promising alternative to current prostheses. However, the contralateral hand is almost always required to operate the mechanism to release a grasp and is sometimes also used to help form the grasp; hence limiting the time it is available for other purposes. In this study we quantified the amount of time the contralateral hand was occupied with operating the Self-Grasping Hand, classified as either direct or indirect interaction, and investigated how these periods changed with practice. We studied 10 anatomically intact participants learning to use the Self-Grasping Hand fitted to a prosthesis simulator. The learning process involved 10 repeats of a feasible subset of the tasks in the Southampton Hand Assessment Procedure (SHAP). Video footage was analysed, and the time that the contralateral hand was engaged in grasping or releasing was calculated. Functionality scores increased for all participants, plateauing at an Index of Functionality of 33.5 after 5 SHAP attempts. Contralateral hand involvement reduced significantly from 6.47 (first 3 attempts) to 4.68 seconds (last three attempts), but as a proportion of total task time remained relatively steady (increasing from 29% to 32%). For 9/10 participants most of this time was supporting the initiation of grasps rather than releases. The reliance on direct or indirect interactions between the contralateral hand and the prosthesis varied between participants but appeared to remain relatively unchanged with practice. Future studies should consider evaluating the impact of reliance on the contralateral limb in day-today life and development of suitable training methods.","","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:42e9b3d1-9421-4da7-9a48-176a55c53871","http://resolver.tudelft.nl/uuid:42e9b3d1-9421-4da7-9a48-176a55c53871","Mechanical evaluation of the “Hüfner hand” prosthesis","Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2021","Background: Current body-powered hands have very low acceptance rates. They also require high activation forces. In the past, a high acceptance rate was reported for the then-available Hüfner hand, a hand which could be controlled by relatively low activation forces. Objective: The aim of this study was to measure and quantify the mechanical performance of the Hüfner hand. Study design: Mechanical evaluation. Methods: Two versions of the Hüfner hand were tested using a mechanical test bench. Forces and displacements were measured under four different glove conditions (no glove, leather, polyvinyl chloride (PVC), silicone). The measured results were compared to data from currently available voluntary-closing hands. Results: The Hüfner hand required 132–170 Nmm of work and 78–104 N cable force to pinch 15 N. The overall mechanical performance of the Hüfner hands is better than currently available body-powered hands. Conclusion: The mechanical performance of the Hüfner hand was measured and quantified. Mechanical testing results show that the Hüfner hand has better mechanical performance than current body-powered hands. This may have contributed to its reported high acceptance rates. The design of the Hüfner hand, combined with data presented in this study, can serve as guidelines for the design of a new generation of body-powered hands.","cineplasty; direct muscle attachment; prosthesis; Sauerbruch; Upper limb","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:ecf56faa-7f89-4fe3-84a1-97a9f65cdb7f","http://resolver.tudelft.nl/uuid:ecf56faa-7f89-4fe3-84a1-97a9f65cdb7f","Design of a 3D-printed hand prosthesis featuring articulated bio-inspired fingers","Cuellar Lopez, J.S. (TU Delft Medical Instruments & Bio-Inspired Technology); Plettenburg, D.H. (TU Delft Biomechatronics & Human-Machine Control); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2021","Various upper-limb prostheses have been designed for 3D printing but only a few of them are based on bio-inspired design principles and many anatomical details are not typically incorporated even though 3D printing offers advantages that facilitate the application of such design principles. We therefore aimed to apply a bio-inspired approach to the design and fabrication of articulated fingers for a new type of 3D printed hand prosthesis that is body-powered and complies with basic user requirements. We first studied the biological structure of human fingers and their movement control mechanisms in order to devise the transmission and actuation system. A number of working principles were established and various simplifications were made to fabricate the hand prosthesis using a fused deposition modelling (FDM) 3D printer with dual material extrusion. We then evaluated the mechanical performance of the prosthetic device by measuring its ability to exert pinch forces and the energy dissipated during each operational cycle. We fabricated our prototypes using three polymeric materials including PLA, TPU, and Nylon. The total weight of the prosthesis was 92 g with a total material cost of 12 US dollars. The energy dissipated during each cycle was 0.380 Nm with a pinch force of ≈16 N corresponding to an input force of 100 N. The hand is actuated by a conventional pulling cable used in BP prostheses. It is connected to a shoulder strap at one end and to the coupling of the whiffle tree mechanism at the other end. The whiffle tree mechanism distributes the force to the four tendons, which bend all fingers simultaneously when pulled. The design described in this manuscript demonstrates several bio-inspired design features and is capable of performing different grasping patterns due to the adaptive grasping provided by the articulated fingers. The pinch force obtained is superior to other fully 3D printed body-powered hand prostheses, but still below that of conventional body powered hand prostheses. We present a 3D printed bio-inspired prosthetic hand that is body-powered and includes all of the following characteristics: adaptive grasping, articulated fingers, and minimized post-printing assembly. Additionally, the low cost and low weight make this prosthetic hand a worthy option mainly in locations where state-of-the-art prosthetic workshops are absent.","3D printing; bio-inspired design; biomedical devices; hand prostheses; mechanical 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.","","2021-06-08","","","Biomechatronics & Human-Machine Control","","",""
"uuid:d86eba46-c765-49fd-9b90-393b33bb7270","http://resolver.tudelft.nl/uuid:d86eba46-c765-49fd-9b90-393b33bb7270","Constructing tree decompositions of graphs with bounded gonality","Bodlaender, Hans L. (Universiteit Utrecht); van Dobben de Bruyn, J. (TU Delft Discrete Mathematics and Optimization); Gijswijt, Dion (TU Delft Discrete Mathematics and Optimization); Smit, Harry (Max Planck Institute for Mathematics in the Sciences)","","2021","In this paper, we give a constructive proof of the fact that the treewidth of a graph is at most its divisorial gonality. The proof gives a polynomial time algorithm to construct a tree decomposition of width at most k, when an effective divisor of degree k that reaches all vertices is given. We also give a similar result for two related notions: stable divisorial gonality and stable gonality.","Chip firing; Gonality; Tree decomposition","en","journal article","","","","","","","","","","","Discrete Mathematics and Optimization","","",""
"uuid:4eadad2b-b7fc-45d9-aa7e-949d13ecb0a6","http://resolver.tudelft.nl/uuid:4eadad2b-b7fc-45d9-aa7e-949d13ecb0a6","A comparative study of point clouds semantic segmentation using three different neural networks on the railway station dataset","Lumban-Gaol, Y. A. (Geospatial Information Agency; Student TU Delft); Chen, Z. (Student TU Delft); Smit, M. (Student TU Delft); Li, X. (Student TU Delft); Erbaşu, M. A. (Student TU Delft); Verbree, E. (TU Delft GIS Technologie; TU Delft Architecture and the Built Environment); Balado Frías, J. (TU Delft GIS Technologie); Meijers, B.M. (TU Delft GIS Technologie); van der Vaart, C.G. (ESRI)","","2021","Point cloud data have rich semantic representations and can benefit various applications towards a digital twin. However, they are unordered and anisotropically distributed, thus being unsuitable for a typical Convolutional Neural Networks (CNN) to handle. With the advance of deep learning, several neural networks claim to have solved the point cloud semantic segmentation problem. This paper evaluates three different neural networks for semantic segmentation of point clouds, namely PointNet++, PointCNN and DGCNN. A public indoor scene of the Amersfoort railway station is used as the study area. Unlike the typical indoor scenes and even more from the ubiquitous outdoor ones in currently available datasets, the station consists of objects such as the entrance gates, ticket machines, couches, and garbage cans. For the experiment, we use subsets from the data, remove the noise, evaluate the performance of the selected neural networks. The results indicate an overall accuracy of more than 90% for all the networks but vary in terms of mean class accuracy and mean Intersection over Union (IoU). The misclassification mainly occurs in the classes of couch and garbage can. Several factors that may contribute to the errors are analyzed, such as the quality of the data and the proportion of the number of points per class. The adaptability of the networks is also heavily dependent on the training location: the overall characteristics of the train station make a trained network for one location less suitable for another.","Deep learning; Indoor Scene; Point Clouds; Railway Station; Semantic Segmentation","en","journal article","","","","","","","","","Architecture and the Built Environment","","GIS Technologie","","",""
"uuid:a69e401b-1d07-4274-9588-44bb0c49c3a3","http://resolver.tudelft.nl/uuid:a69e401b-1d07-4274-9588-44bb0c49c3a3","Stabilizing interventional instruments in the cardiovascular system: A classification of mechanisms","Ali, A. (TU Delft Medical Instruments & Bio-Inspired Technology); Dodou, D. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Rink, Ruben (Student TU Delft); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2021","Positioning and stabilizing a catheter at the required location inside a vessel or the heart is a complicated task in interventional cardiology. In this review we provide a structured classification of catheter stabilization mechanisms to systematically assess their challenges during cardiac interventions. Commercially available, patented, and experimental prototypes of catheters were classified with respect to their stabilizing mechanisms. Subsequently, the classification was used to define requirements for future cardiac catheters and persisting challenges in catheter stabilization. The classification showed that there are two main stabilization mechanisms: surface-based and volume-based. Surface-based mechanisms apply attachment through surface anchoring, while volume-based mechanisms make use of locking through shape or force against the vessel or cardiac wall. The classification provides insight into existing catheter stabilization mechanisms and can possibly be used as a tool for future design of catheter stabilization mechanisms to keep the catheter at a specific location during an intervention. Additionally, insight into the requirements and challenges for catheter stabilization inside the heart and vasculature can lead to the development of more dedicated systems in the future, allowing for intervention- and patient-specific instrument manipulation.","Anchoring; Catheter; Classification; Dynamic environment; Interventional cardiology; Stabilizing","en","review","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:5c319603-28b6-4bf2-9670-cb9ce4393d60","http://resolver.tudelft.nl/uuid:5c319603-28b6-4bf2-9670-cb9ce4393d60","Remote Actuation Systems for Fully Wearable Assistive Devices: Requirements, Selection, and Optimization for Out-of-the-Lab Application of a Hand Exoskeleton","Dittli, Jan (ETH Zürich); Hofmann, Urs A.T. (ETH Zürich); Bützer, Tobias (ETH Zürich); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Lambercy, Olivier (ETH Zürich); Gassert, Roger (ETH Zürich)","","2021","Wearable robots assist individuals with sensorimotor impairment in daily life, or support industrial workers in physically demanding tasks. In such scenarios, low mass and compact design are crucial factors for device acceptance. Remote actuation systems (RAS) have emerged as a popular approach in wearable robots to reduce perceived weight and increase usability. Different RAS have been presented in the literature to accommodate for a wide range of applications and related design requirements. The push toward use of wearable robotics in out-of-the-lab applications in clinics, home environments, or industry created a shift in requirements for RAS. In this context, high durability, ergonomics, and simple maintenance gain in importance. However, these are only rarely considered and evaluated in research publications, despite being drivers for device abandonment by end-users. In this paper, we summarize existing approaches of RAS for wearable assistive technology in a literature review and compare advantages and disadvantages, focusing on specific evaluation criteria for out-of-the-lab applications to provide guidelines for the selection of RAS. Based on the gained insights, we present the development, optimization, and evaluation of a cable-based RAS for out-of-the-lab applications in a wearable assistive soft hand exoskeleton. The presented RAS features full wearability, high durability, high efficiency, and appealing design while fulfilling ergonomic criteria such as low mass and high wearing comfort. This work aims to support the transfer of RAS for wearable robotics from controlled lab environments to out-of-the-lab applications.","assistive device; Bowden cable; cable-driven; hand exoskeleton; out-of-the-lab; remote actuation; soft robotics; wearable robot","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:2025fc04-5e7e-4509-8834-3eb3b19f1ae9","http://resolver.tudelft.nl/uuid:2025fc04-5e7e-4509-8834-3eb3b19f1ae9","Efficient two-layer non-hydrostatic wave model with accurate dispersive behaviour","de Ridder, M.P. (Deltares); Smit, Pieter B. (Sofar Ocean Technologies); van Dongeren, Ap R. (Deltares; IHE Delft Institute for Water Education); McCall, Robert T. (Deltares); Nederhoff, Kees (Deltares-USA); Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics)","","2021","A 2-layer non-hydrostatic model with improved dispersive behaviour is presented. Due to the assumption of a constant non-hydrostatic pressure distribution in the lower layer, the dispersive behaviour is improved without much additional computational time. A comparison with linear wave theory showed that this 2-layer model gives a better result for the dispersion relation and shoaling of waves in intermediate water. This means that the 2-layer model is applicable in shallow and intermediate water depths (up to relative depths kh equals 4), whereas the 1-layer model is only applicable in shallow water depths (kh smaller than 1). Three laboratory experiments, including a fringing reef and a barred beach, were used to validate the presented mode for different hydrodynamic conditions. Based on these results, it can be concluded that the 2-layer model can be applied to accurately simulate the bulk wave height and spectral properties. The low frequency wave height, the setup and in particular the second order statistics contain more scatter, but the model accurately captured the general trend. Furthermore, the model showed good results for complex bathymetries in shallow to intermediate water.","Dispersive behaviour; Non-hydrostatic model; Wave modelling; XBeach","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.","","2021-05-05","","","Environmental Fluid Mechanics","","",""
"uuid:26dfa0a8-4b5e-48de-91ec-d1cbc42d4a05","http://resolver.tudelft.nl/uuid:26dfa0a8-4b5e-48de-91ec-d1cbc42d4a05","Three-dimensional unsteady stator-rotor interactions in high-expansion organic Rankine cycle turbines","Otero Rodriguez, G.J. (TU Delft Energy Technology); Smit, S.H.H.J. (TU Delft Energy Technology); Pecnik, Rene (TU Delft Energy Technology)","","2021","Organic Rankine cycle (ORC) systems are a readily available technology to convert thermal energy from renewable- and waste heat sources into electricity. However, their thermal performance is relatively low due to the low temperature of the available heat sources, but more importantly, due to the low efficiency of the employed expander. Designing the turboexpander is exceptionally challenging, because the flow field is highly supersonic and unsteady, and since the expansion takes place in the highly non-ideal dense-vapor region. In this work, we perform unprecedented three-dimensional unsteady simulations of several high-expansion cantilever ORC turbines to highlight distinctive loss mechanisms. The simulations indicate strong unsteady effects in the rotor blade passage, as a result of unsteady propagating shock waves interacting with viscous wakes and boundary layers. Moreover, the flow field in the rotor blade passage is strongly affected by three-dimensional secondary flow features and a sharp expansion in the shroud region at the inlet of the rotor blade. These span-wise mechanisms and unsteady flow interactions introduce irreversible losses which must be taken into account for designing highly efficient ORC expanders.","High-expansion radial inflow turbines; ORC power systems; stator-rotor unsteady interaction; Three-dimensional simulations","en","journal article","","","","","","","","","","","Energy Technology","","",""
"uuid:a0c2a0d3-bf1e-4be5-955a-92f22868530a","http://resolver.tudelft.nl/uuid:a0c2a0d3-bf1e-4be5-955a-92f22868530a","Partial discharges activated by impulses and superimposed voltages in a high voltage cable model","Wu, J. (TU Delft DC systems, Energy conversion & Storage); Smit, J.J. (TU Delft EEMS - General); Mor, A. R. (TU Delft DC systems, Energy conversion & Storage)","","2020","In practice, High-voltage (HV) cables are occasionally exposed to impulse and superimposed transient conditions, which may initiate partial discharges (PD) temporarily. Whether such PDs persist under AC voltage after the transient conditions have vanished, is at focus in the research described in this paper. Since for cross-linked polyethylene (XLPE) cables the accessories are weak links in the HV cable insulation system, we investigated the PD behavior of an artificial joint defect in a HV cable model under impulse and superimposed voltages. By applying a dedicated PD measuring system it was found that, the impulse and superimposed voltages can initiate PD in the artificial defect, which under local electrical field conditions can persist for some time. The different parameters of the applied voltages have different effects on the PD behavior.","High-voltage cross-linked polyethylene (XLPE) cable model joint defect; Impulse voltage; Partial discharge (PD); Superimposed voltage","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:45d31353-c1d4-4590-8126-9f555d61129a","http://resolver.tudelft.nl/uuid:45d31353-c1d4-4590-8126-9f555d61129a","Modelling statistical wave interferences over shear currents","Akrish, G. (TU Delft Environmental Fluid Mechanics); Smit, Pieter (Sofar Ocean Technologies); Zijlema, Marcel (TU Delft Environmental Fluid Mechanics); Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics)","","2020","Wave forecasting in ocean and coastal waters commonly relies on spectral models based on the spectral action balance equation. These models assume that different wave components are statistically independent and as a consequence cannot resolve wave interference due to statistical correlation between crossing waves, as may be found in, for instance, a focal zone. This study proposes a statistical model for the evolution of wave fields over non-uniform currents and bathymetry that retains the information on the correlation between different wave components. To this end, the quasi-coherent model (Smit & Janssen, J. Phys. Oceanogr., vol. 43, 2013, pp. 1741-1758) is extended to allow for wave-current interactions. The outcome is a generalized action balance model that predicts the evolution of the wave statistics over variable media, while preserving the effect of wave interferences. Two classical examples of wave-current interaction are considered to demonstrate the statistical contribution of wave interferences: (1) swell field propagation over a jet-like current and (2) the interaction of swell waves with a vortex ring. In both examples cross-correlation terms lead to development of prominent interference structures, which significantly change the wave statistics. Comparison with results of the SWAN model demonstrates that retention of cross-correlation terms is essential for accurate prediction of wave statistics in shear-current-induced focal zones.","surface gravity waves; wave scattering","en","journal article","","","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:415dcfad-a7f2-4845-ac09-1b9a7d0cdc5c","http://resolver.tudelft.nl/uuid:415dcfad-a7f2-4845-ac09-1b9a7d0cdc5c","Computing graph gonality is hard","Gijswijt, Dion (TU Delft Discrete Mathematics and Optimization); Smit, Harry J. (Universiteit Utrecht); van der Wegen, Marieke (Universiteit Utrecht)","","2020","There are several notions of gonality for graphs. The divisorial gonality dgon(G) of a graph G is the smallest degree of a divisor of positive rank in the sense of Baker-Norine. The stable gonality sgon(G) of a graph G is the minimum degree of a finite harmonic morphism from a refinement of G to a tree, as defined by Cornelissen, Kato and Kool. We show that computing dgon(G) and sgon(G) are NP-hard by a reduction from the maximum independent set problem and the vertex cover problem, respectively. Both constructions show that computing gonality is moreover APX-hard.","Gonality; Computational complexity; Chip-firing; Graph theory; Tropical geometry","en","journal article","","","","","","","","","","","Discrete Mathematics and Optimization","","",""
"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:059e34ba-44e7-4f33-b2de-0b277e207376","http://resolver.tudelft.nl/uuid:059e34ba-44e7-4f33-b2de-0b277e207376","Mechanical aspects of robot hands, active hand orthoses and prostheses: A comparative review","Vertongen, J. (Student TU Delft); Kamper, Derek G. (University of North Carolina at Chapel Hill; North Carolina State University); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Vallery, H. (TU Delft Biomechatronics & Human-Machine Control)","","2020","The large interest in robot hands and active hand prostheses has in recent years been joined by that in active hand orthoses. Despite the differences in intended uses, these three categories of artificial hand devices share key characteristics. Examination of the commonalities could stimulate future design. Thus, in this article, we undertook a comparative review of publications describing robot hands, active prostheses, and active orthoses, with a focus on mechanical structure, actuation principle, and transmission. Out of a total of 510 papers identified through the literature search, 72 publications were included in a focused examination. We identified trends in the design of artificial hands and gaps in the literature. After comparing their mechanical aspects, we propose recommendations for future development.","Hands; robotics; prosthetics; orthotics; dexterity; Dexterity; Gands; Orthotics; Robotics; Prosthetics","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.","","2021-02-04","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:8a8ff540-209f-477a-b849-0e5dc402fa33","http://resolver.tudelft.nl/uuid:8a8ff540-209f-477a-b849-0e5dc402fa33","Constructing tree decompositions of graphs with bounded gonality","Bodlaender, Hans L. (Universiteit Utrecht); van Dobben de Bruyn, J. (TU Delft Discrete Mathematics and Optimization); Gijswijt, Dion (TU Delft Discrete Mathematics and Optimization); Smit, Harry (Universiteit Utrecht)","Kim, Donghyun (editor); Uma, R.N. (editor); Cai, Zhipeng (editor); Lee, Dong Hoon (editor)","2020","In this paper, we give a constructive proof of the fact that the treewidth of a graph is at most its divisorial gonality. The proof gives a polynomial time algorithm to construct a tree decomposition of width at most k, when an effective divisor of degree k that reaches all vertices is given. We also give a similar result for two related notions: stable divisorial gonality and stable gonality.","","en","conference paper","Springer","","","","","Accepted author manuscript","","","","","Discrete Mathematics and Optimization","","",""
"uuid:3b41b8a1-3bc7-41bd-8841-5936a3b78f86","http://resolver.tudelft.nl/uuid:3b41b8a1-3bc7-41bd-8841-5936a3b78f86","Making water security: A morphological account of Nile River development","Smit, H. (TU Delft Water Resources)","van der Zaag, P. (promotor); Ahlers, R. (copromotor); Delft University of Technology (degree granting institution)","2019","This dissertation examines Nile water security through the morphology of the river. Water projects are often legitimized by arguing that they will increase the reliability of water or increase its availability for abstract populations. Such analyses often leave unexplained who specifically benefit from these projects and, more so, who do not. Examining the morphology of the river – its form and structure – allows for a historical and material understanding of how hydraulic infrastructure and discourses of water security develop and what this means to whom. My aim is to better understand how scientists, engineers and water users engage in rearranging the morphology of the Nile and in so doing shape their relative positions vis-à-vis each other and the river. In this way the dissertation seeks to support more equitable and sustainable forms of Nile development.","","en","doctoral thesis","CRC Press / Balkema - Taylor & Francis Group","978-0-367-46004-4","","","","Dissertation submitted in fulfillment of the requirements of the Board for Doctorates of Delft University of Technology and of the Academic Board of IHE Delft Institute for Water Education","","","","","Water Resources","","",""
"uuid:c2204878-2910-4e2a-8639-828062fc2184","http://resolver.tudelft.nl/uuid:c2204878-2910-4e2a-8639-828062fc2184","Health index and risk assessment models for Gas Insulated Switchgear (GIS) operating under tropical conditions","Purnomoadi, A.P. (PLN Research Institute); Mor, A. R. (TU Delft DC systems, Energy conversion & Storage); Smit, J.J. (TU Delft EEMS - General)","","2019","This article contains the development of the Health Index (HI) and the Risk Assessment (RA) models for Gas Insulated Switchgear (GIS) operating under tropical conditions. A case study of 631 bays of GIS in tropics with service time from 1 up to 30 years is used during the development of the models. The basis for the HI model is the condition assessment of subsystems in GIS. This assessment translates the measured parameters from GIS subsystems into condition status based on a set of norms and rules. The condition status is presented in a score, where the non-linear scaling is chosen as it allows the poor parameters to really stand out. On the other hand, the RA model calculates the risk of a GIS major failure. The Total Failure Probability (TPF) unifies six risk indicators of GIS failures under tropical conditions. The risk may fall into one of the four categories, namely: Low, Medium, High, and Very High.","Health Index; RiskAssessment; AssetManagement; Gas-InsulatedSwitchgear; Tropicalconditions","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:726fe671-114a-4db8-9146-dad272153f80","http://resolver.tudelft.nl/uuid:726fe671-114a-4db8-9146-dad272153f80","Measuring method for partial discharges in a high voltage cable system subjected to impulse and superimposed voltage under laboratory conditions","Wu, J. (TU Delft DC systems, Energy conversion & Storage); Mor, A. R. (TU Delft DC systems, Energy conversion & Storage); van Nes, P.V.M. (TU Delft ESP LAB); Smit, J.J. (TU Delft EEMS - General)","","2019","A partial discharge (PD) measuring system has been deployed in order to identify and measure PD in a high voltage (HV) cable joint under impulse and superimposed voltages under laboratory conditions. The challenge is to enable the detection of PD during the impulse conditions. The method of measurement has been investigated by introducing an artificial defect in the cable joint in a controlled way to create conditions for partial discharges to occur. Next the HV cable system is subjected to AC, impulse and superimposed voltage. Two high frequency current transformers (HFCT) installed at both ends of the cable joint were used to identify PD from the cable joint and to separate PD from disturbance. Transient voltage suppressors and spark gaps are applied to protect the measuring equipment. Band pass filters with selected characteristics are applied to suppress transient disturbances and increase the chance to detect PD during the impulse. PD signals are separated from transient disturbances during data post processing and by means of pulse polarity analysis. The developed system enables the detection of so-called main and reverse discharges respectively occurring during the rise and tail time of the superimposed impulse. The measurement results obtained show the effectiveness of the presented PD measuring system for investigating the effects of voltage transients on a HV cable system in laboratory conditions.","Band-pass filter; High frequency current transformer; High voltage cable joint; Partial discharge measuring method; Superimposed voltage conditions","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:30039fd9-31f4-421e-9d67-23869fee74c8","http://resolver.tudelft.nl/uuid:30039fd9-31f4-421e-9d67-23869fee74c8","Spacer flashover in Gas Insulated Switchgear (GIS) with humid SF6 under different electrical stresses","Purnomoadi, A.P. (TU Delft DC systems, Energy conversion & Storage; PLN Research Institute); Mor, A. R. (TU Delft DC systems, Energy conversion & Storage); Smit, J.J. (TU Delft EEMS - General)","","2019","Humid insulating gas (SF6) has been observed in a case study of 631 CB-bays of Gas Insulated Switchgear (GIS) operating under tropical conditions. The routine gas quality check in the case study reported that 20% of the non-Circuit Breaker enclosures have humidity above the value recommended by the IEEE and IEC standards. Therefore, an investigation into the flashover characteristics of a spacer in humid SF6 has been initiated in the High Voltage Laboratory of TU Delft, The Netherlands. The setup is a small model resembling the insulation system of a GIS with controlled parameters of humidity content and gas pressure. The electrical stresses in the test are AC, LI+, LI−, and SI with homogeneous, quasi-homogeneous-, and inhomogeneous field configurations. In general, the humidity does not influence the withstand strength of the spacer as long there is no condensation. When condensation occurred, the flashover voltage dropped by 28% during the test under AC at 2.6 bars, and by 38% during the test under LI+ at 2.5 bars; both with quasi-homogeneous field configuration. In the test with homogeneous field setup, the flashover voltage was dropped by 67% under LI+ at 3.4 bars. In our setup, it has also been observed that the flashover-drop due to condensation is higher than due to a 2-mm aluminum particle attached to the sample close to the high electric field region simulating the inhomogeneous field configuration.","Gas insulated switchgear; Gas insulated substation; GIS; Tropical conditions; Humid insulting gas; Spacer flashover; SF6","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:3e6745e0-d87e-41a7-8271-ae18f2acbdd4","http://resolver.tudelft.nl/uuid:3e6745e0-d87e-41a7-8271-ae18f2acbdd4","Middle Paleolithic complex technology and a Neandertal tar-backed tool from the Dutch North Sea","Niekus, Marcel J. L. Th. (Stichting STONE/Foundation for Stone Age Research in The Netherlands); Kozowyk, Paul R. B. (Universiteit Leiden); Langejans, G.H.J. (TU Delft (OLD) MSE-4; University of Johannesburg); Ngan-Tillard, D.J.M. (TU Delft Geo-engineering); van Keulen, Henk (Cultural Heritage Agency of the Netherlands); van der Plicht, Johannes (Rijksuniversiteit Groningen); Cohen, Kim M. (Universiteit Utrecht); van Os, Bertil (Cultural Heritage Agency of the Netherlands); Smit, Bjørn I. (Cultural Heritage Agency of the Netherlands)","","2019","We report the discovery of a 50,000-y-old birch tar-hafted flint tool found off the present-day coastline of The Netherlands. The production of adhesives and multicomponent tools is considered complex technology and has a prominent place in discussions about the evolution of human behavior. This find provides evidence on the technological capabilities of Neandertals and illuminates the currently debated conditions under which these technologies could be maintained. 14C-accelerator mass spectrometry dating and the geological provenance of the artifact firmly associates it with a host of Middle Paleolithic stone tools and a Neandertal fossil. The find was analyzed using pyrolysis-gas chromatography-mass spectrometry, X-ray micro-computed tomography, and optical light microscopy. The object is a piece of birch tar, encompassing one-third of a flint flake. This find is from northwestern Europe and complements a small set of well-dated and chemically identified adhesives from Middle Paleolithic/Middle Stone Age contexts. Together with data from experiments and other Middle Paleolithic adhesives, it demonstrates that Neandertals mastered complex adhesive production strategies and composite tool use at the northern edge of their range. Thus, a large population size is not a necessary condition for complex behavior and technology. The mitigation of ecological risk, as demonstrated by the challenging conditions during Marine Isotope Stage 4 and 3, provides a better explanation for the transmission and maintenance of technological complexity.","Late Pleistocene; Hafting; Birch bark tar; Adhesive; Risk mitigation","en","journal article","","","","","","","","","","","(OLD) MSE-4","","",""
"uuid:d40742d0-b829-4def-8567-0913148d0a36","http://resolver.tudelft.nl/uuid:d40742d0-b829-4def-8567-0913148d0a36","Mechanical Follow-the-Leader motion of a hyper-redundant surgical instrument: Proof-of-concept prototype and first tests","Henselmans, P.W.J. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2019","One of the most prominent drivers in the development of surgical procedures is the will to reduce their invasiveness, attested by minimally invasive surgery being the gold standards in many surgical procedures and natural orifices transluminal endoscopic surgery gaining acceptance. A logical next step in this pursuit is the introduction of hyper-redundant instruments that can insert themselves along multi-curved paths referred to as Follow-the-Leader motion. In the current state of the art, two different types of Follow-the-Leader instruments can be distinguished. One type of instrument is robotized; the movements of the shaft are controlled from outside the patient by actuators, for example, electric motors, and a controller storing a virtual track of the desired path. The other type of instrument is more mechanical; the movements of the shaft are controlled from inside the patient by a physical track that guides the shaft along the desired path. While in the robotized approach all degrees of freedom of the shaft require an individual actuator, the mechanical approach makes the number of degrees of freedom independent from the number of actuators. A desirable feature as an increasing number of actuators will inevitably drive up costs and increase the footprint of an instrument. Building the physical track inside the body does, however, impede miniaturization of the shaft's diameter. This article introduces a new fully mechanical approach for Follow-the-Leader motion using a pre-determined physical track that is placed outside the body. This new approach was validated with a prototype called MemoFlex, which supports a Ø5 mm shaft (standard size in minimally invasive surgery) that contains 28-degrees-of-freedom and utilizes a simple steel rod as its physical track. Even though the performance of the MemoFlex leaves room for improvement, especially when following multiple curves, it does validate the proposed concept for Follow-the-Leader motion in three-dimensional space.","Follow-the-Leader; hyper-redundant; minimally invasive surgery; natural orifices transluminal endoscopic surgery; pathway surgery; snake-like; surgical instruments; tendon-driven","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:3cd1d1b1-8834-4e36-a6a6-f52083c2d4bf","http://resolver.tudelft.nl/uuid:3cd1d1b1-8834-4e36-a6a6-f52083c2d4bf","Functional evaluation of a non-assembly 3D-printed hand prosthesis","Cuellar Lopez, J.S. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Plettenburg, D.H. (TU Delft Biomechatronics & Human-Machine Control)","","2019","In developing countries, the access of amputees to prosthetic devices is very limited. In a way to increase accessibility of prosthetic hands, we have recently developed a new approach for the design and 3D printing of non-assembly active hand prostheses using inexpensive 3D printers working on the basis of material extrusion technology. This article describes the design of our novel 3D-printed hand prosthesis and also shows the mechanical and functional evaluation in view of its future use in developing countries. We have fabricated a hand prosthesis using 3D printing technology and a non-assembly design approach that reaches certain level of functionality. The mechanical resistance of critical parts, the mechanical performance, and the functionality of a non-assembly 3D-printed hand prosthesis were assessed. The mechanical configuration used in the hand prosthesis is able to withstand typical actuation forces delivered by prosthetic users. Moreover, the activation forces and the energy required for a closing cycle are considerably lower as compared to other body-powered prostheses. The non-assembly design achieved a comparable level of functionality with respect to other body-powered alternatives. We consider this prosthetic hand a valuable option for people with arm defects in developing countries.","3D printing; biomechanical testing/analysis; biomedical devices; limb prosthetics; mechanical design","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:fe65064a-45e7-43ea-90d2-c266bcf6dc55","http://resolver.tudelft.nl/uuid:fe65064a-45e7-43ea-90d2-c266bcf6dc55","The effects of superimposed impulse transients on partial discharge in XLPE cable joint","Wu, J. (TU Delft DC systems, Energy conversion & Storage); Mor, A. R. (TU Delft DC systems, Energy conversion & Storage); Smit, J.J. (TU Delft EEMS - General)","","2019","In practice, cross-linked polyethylene (XLPE) power cables can be subjected to alternating voltage with superimposed impulse transients. Such impulse transients may initiate partial discharges (PD) in insulation defects even below AC inception voltage. An initiated PD may persist under AC, which will cause insulation degradation. This paper investigates the PD behavior in MV XLPE cable accessories under impulse transients. Different scenarios of PD behavior are measured, described and analyzed. Based on the results, the effects of impulse transients on PD are summarized.","XLPE cable; Cable accessories; Insulation defects; Partial discharge (PD); Impulse transients","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:5aa7de20-9d6f-4b89-bc10-69918a2d09d9","http://resolver.tudelft.nl/uuid:5aa7de20-9d6f-4b89-bc10-69918a2d09d9","New Capillary Number Definition for Micromodels: The Impact of Pore Microstructure","Tang, J. (TU Delft Reservoir Engineering); Smit, Michiel (Student TU Delft); Vincent-Bonnieu, S.Y.F. (TU Delft Reservoir Engineering; Shell Global Solutions International B.V.); Rossen, W.R. (TU Delft Reservoir Engineering)","","2019","A new capillary number (N ca ) definition is proposed for 2-D etched micromodels. We derive the new definition from a force balance on a nonwetting ganglion trapped by capillarity. It incorporates the impact of pore microstructure on mobilization. The geometrical factors introduced can be estimated directly from image analysis of the pore network etched in the micromodel, without conducting flow experiments. The improved fit of the new N ca to published data supports its validity. The new definition yields a consistent trend in the capillary-desaturation curve. The conventional N ca definitions proposed for porous rock give a large scatter in the capillary-desaturation curve for data in micromodels. This is due to the different type of flow in micromodels, as 2-D networks, relative to 3-D geological porous media. In particular, permeability is dominated by channel depth in micromodels with shallow depth of etching, and generally, there is no simultaneous multiphase flow under capillary-dominated conditions. Applying the conventional definitions to results in micromodels may lead to misleading conclusions for fluid transport in geological formations.","capillary number; fluid transport; micromodels; nonwetting-phase mobilization; pore microstructure","en","journal article","","","","","","","","","","","Reservoir Engineering","","",""
"uuid:6da6ebff-a33a-4459-ac0a-b0c05ee6bc92","http://resolver.tudelft.nl/uuid:6da6ebff-a33a-4459-ac0a-b0c05ee6bc92","A review of the fatigue behavior of 3D printed polymers","Safai, Lauren (Student TU Delft); Cuellar Lopez, J.S. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2019","As additive manufacturing of polymeric materials is becoming more prevalent throughout industry and research communities, it is important to ensure that 3D printed parts are able to withstand mechanical and environmental stresses that occur when in use, including the sub-critical cyclic loads that could result in fatigue crack propagation and material failure. There has so far been only limited research on the fatigue behavior of 3D printed polymers to determine which printing or material parameters result in the most favorable fatigue behavior. To better understand the effects of the printing technique, printing materials, and printing parameters on the fatigue behavior of 3D printed materials, we present here an overview of the data currently available in the literature including fatigue testing protocols and a quantitative analysis of the available fatigue data per type of the AM technology. The results of our literature review clearly show that, due to the synergism between printing parameters and the properties of the printed material, it is challenging to determine the best combination of variables for fatigue resistance. There is therefore a need for more experimental and computational fatigue studies to understand how the above-mentioned material and printing parameters affect the fatigue behavior.","3D printing; Cyclic loading; Fatigue fracture; Mechanical behavior; Polymers","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.","","2019-10-06","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:5c81b8e3-1807-41b0-803f-f806b6398af5","http://resolver.tudelft.nl/uuid:5c81b8e3-1807-41b0-803f-f806b6398af5","Additive manufacturing of medical instruments: A state-of-the-art review","Culmone, C. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2019","Goal: Additive manufacturing, also known as 3D printing, has begun to play a significant role in the field of medical devices. This review aims to provide a comprehensive overview and classification of additively manufactured medical instruments for diagnostics and surgery by identifying medical and technical aspects. Methods: A scientific literature search on additively manufactured medical instruments was conducted using the Scopus database. Results: We categorized the relevant articles (71) by considering the novelty of each proposed instrument and its clinical application. Then, we analyzed the relevant articles by examining the reasons behind choosing additive manufacturing technology to produce instruments for diagnostics and surgery. Possible customization (27%) and Cost-effectiveness (23%) were the main reasons expressed. Technical specifications of the additive manufacturing technology and the material used were also analyzed, and a tendency of using material extrusion technology (35% of the applications) and polymeric materials (86% of the applications) was shown. Conclusions: Additive manufacturing is opening the door to a new approach in the production of medical devices, which allows the complexity of their designs to be pushed to the extreme. However, we found that technical limitations need to be tackled and important aspects such as sterilization or debris contamination are still not considered to be relevant factors during the design and fabrication process. Keeping in mind the challenges of such a new field, additive manufacturing technology can be considered as a great opportunity to provide easy access to healthcare in developing countries as well as an important step toward patient-specific medicine.","3D printing; Additive manufacturing; Medical device; Medical instrument; Review","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.","","2019-10-01","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:1763c625-5a39-4f2a-bfad-c3af05cf41d1","http://resolver.tudelft.nl/uuid:1763c625-5a39-4f2a-bfad-c3af05cf41d1","Subsidence of organic dredged sediments in an upland deposit in Wormer- en Jisperveld: North Holland, the Netherlands","Oliveira, Bruna R F (Wageningen University & Research); Smit, Martijn P J (Wageningen University & Research); Veld, Harry (Deltares); van Paassen, L.A. (TU Delft Geo-engineering); Rijnaarts, Huub H M (Wageningen University & Research); Grotenhuis, Tim C. (Wageningen University & Research)","","2018","Land subsidence in low-lying peatlands can be caused by shrinkage and organic matter oxidation. When these areas have networks of ditches and canals for drainage purposes, the sediments that accumulate in the waterways can be used to reverse the process of land subsidence. The objective of this study is to understand how dredged sediments can be used to reverse the process of land subsidence by analysing the contribution of shrinkage and organic matter mineralization to the subsidence observed in an upland deposit. A deposit of dredged sediments in the Wormer- en Jisperveld—North Holland, the Netherlands—was characterized during 17 months in terms of subsidence of the sediments, subsidence of the soil underlying the deposit, geotechnical water content, organic matter content, type of organic matter and nutrients. The deposit was filled to a height of 195 cm, and after 17 months, the subsidence of the sediments was 88 cm. In addition, a subsidence of 19.5 cm of the underlying soil was observed. Subsidence could be attributed to shrinkage since no significant changes in the organic matter content and total organic carbon were observed. The type of organic matter changed in the direction of humification until winter 2014, stabilized from winter 2014 to spring 2015 and changed in the direction of mineralization after the spring of 2015. Subsidence of dredged sediments in upland deposits is caused by shrinkage during the first 17 months. The solution of spreading thinner layers of sediments over the land to decrease the subsidence rates should be explored since the pressure of the deposit on the underlying soil caused an extra subsidence of 19.5 cm.","Dredged sediments; Lowlands; Organic matter oxidation; Peatlands; Shrinkage; Subsidence; Upland deposit","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:37e6dd64-0ac6-409b-8611-46276e001981","http://resolver.tudelft.nl/uuid:37e6dd64-0ac6-409b-8611-46276e001981","Anterior longitudinal ligament in diffuse idiopathic skeletal hyperostosis: Ossified or displaced?","Kuperus, J.S. (University Medical Center Utrecht); Smit, E.J.M. (University Medical Center Utrecht); Pouran, B. (TU Delft Biomaterials & Tissue Biomechanics); van Hamersvelt, R.W. (University Medical Center Utrecht); van Stralen, Marijn (Universiteit Utrecht); Seevinck, P.R. (Universiteit Utrecht); Buckens, C.F. (University Medical Center Utrecht); Bleys, Ronald L.A.W. (University Medical Center Utrecht); Weinans, Harrie (TU Delft Biomaterials & Tissue Biomechanics); Oner, F. C. (University Medical Center Utrecht); de Jong, P.A. (University Medical Center Utrecht); Verlaan, J-J (University Medical Center Utrecht)","","2018","Diffuse idiopathic skeletal hyperostosis (DISH) is often theorized to be an ossification of the anterior longitudinal ligament (ALL). Using computed tomography (CT) imaging and cryomacrotome sectioning, we investigated the spatial relationship between the ALL and newly formed bone in DISH to test this hypothesis. In the current study, four human cadaveric spines diagnosed with DISH using CT imaging were frozen and sectioned using a cryomacrotome. Photographs were obtained of the specimen at 125 µm intervals. Manual segmentations of the ALL on cryomacrotome photographs were projected onto the three-dimensional reconstructed CT scans. The presence and location of newly formed bone were assessed in relationship to the location of the ALL. The ALL could be identified and segmented on the photographs at all levels. The ALL was located at the midline at levels where no new bone had formed. At the locations where new bone had abundantly formed, the ALL was displaced towards to the contralateral side and not replaced by bony tissue. The displacement of the—morphologically normal appearing—ALL away from the newly formed bone implies that newly formed bone in DISH may not originate from the ALL.","anterior longitudinal ligament; bone/bone biology; computed tomography; cryomacrotome; diffuse idiopathic skeletal hyperostosis; pathogenesis; spine","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:0bdd2522-24f4-47ce-82c6-45db98003bae","http://resolver.tudelft.nl/uuid:0bdd2522-24f4-47ce-82c6-45db98003bae","Ten guidelines for the design of non-assembly mechanisms: The case of 3D-printed prosthetic hands","Cuellar Lopez, J.S. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2018","In developing countries, prosthetic workshops are limited, difficult to reach, or even non-existent. Especially, fabrication of active, multi-articulated, and personalized hand prosthetic devices is often seen as a time-consuming and demanding process. An active prosthetic hand made through the fused deposition modelling technology and fully assembled right after the end of the 3D printing process will increase accessibility of prosthetic devices by reducing or bypassing the current manufacturing and post-processing steps. In this study, an approach for producing active hand prosthesis that could be fabricated fully assembled by fused deposition modelling technology is developed. By presenting a successful case of non-assembly 3D printing, this article defines a list of design considerations that should be followed in order to achieve fully functional non-assembly devices. Ten design considerations for additive manufacturing of non-assembly mechanisms have been proposed and a design case has been successfully addressed resulting in a fully functional prosthetic hand. The hand prosthesis can be 3D printed with an inexpensive fused deposition modelling machine and is capable of performing different types of grasping. The activation force required to start a pinch grasp, the energy required for closing, and the overall mass are significantly lower than body-powered commercial prosthetic hands. The results suggest that this non-assembly design may be a good alternative for amputees in developing countries.","Additive manufacturing; biomechanical testing/analysis; limb prosthetics; mechanical design; non-assembly design","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:124eec25-0cb7-498c-a97e-3d71f18fe47b","http://resolver.tudelft.nl/uuid:124eec25-0cb7-498c-a97e-3d71f18fe47b","Design of a novel three- dimensional-printed two degrees-of-freedom steerable electrosurgical grasper for minimally invasive surgery","Sakes, A. (TU Delft Medical Instruments & Bio-Inspired Technology); Hovland, Kevin (Student TU Delft); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Geraedts, Jo M.P. (TU Delft Mechatronic Design); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2018","In current bipolar electrosurgical instruments, a high frequency electrical sinusoidal wave is passed through the patient's body from an active electrode to the return electrode to cut, coagulate, or desiccate tissues. Even though current bipolar electrosurgical instruments have proven effective in minimizing blood loss, advancement is needed to allow for improved dexterity and adaptability. With current advances in threedimensional (3D)-print processes and its integration in the medical field, it has become possible to manufacture patient-and operation-specific instruments. In this study, we introduce the first 3D-printed steerable bipolar grasper (□ 5 mm) for use in minimal invasive surgery. The grasper significantly improves dexterity by the addition of two planar joints allowing for ±65 deg for sideways and ±85 deg for up- and downward movement. The joints enable a significantly higher bending stiffness, 4.0 N/mm for joint 1 and 4.4 N/mm for joint 2, than that of currently available steerable instruments. The tip consists of two metallic movable jaws that can be opened and closed with angles up to 170 deg and allows for grasping and coagulating of tissues; reaching tissue temperatures of over 75 °C for an activation time of ~5 s, respectively. In order to actuate the joint, tip, and electrosurgical system, as well as to tension the steering cables, a ring handle was designed. In summary, the 3D-printed steerable bipolar grasper provides the surgeon with electrosurgical capabilities, improved dexterity, improved stiffness, and the versatility that is needed to provide patient- and operation-specific care.","3D-printing; Additive manufacturing; Bipolar electrosurgery; Medical device design; Minimally invasive surgery; Steerable instruments","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.","","2018-07-10","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:0a7068f3-0ef8-4db4-9c53-7dbb56759b3b","http://resolver.tudelft.nl/uuid:0a7068f3-0ef8-4db4-9c53-7dbb56759b3b","Thinking out of the Box: Comparing metaphors for variables in programming education","Hermans, F.F.J. (TU Delft Software Engineering); Swidan, A.A.S. (TU Delft Software Engineering); Aivaloglou, E.A. (Open University of the Netherlands); Smit, M.I.E. (TU Delft Software Engineering)","","2018","When teaching novices programming, misconceptions can occur. Misconception are incorrect beliefs about certain programming concept. For example, some novices think that a variable can hold multiple values, in the case of two consecutive assignment statements, such as x = 5; x = 7. While explaining variables introductory materials often use the metaphor of a box for a variable, which might contribute to the 'multiple values' hypothesis. To investigate this, we design and run a controlled experiment with 496 novice programmers, both children and adults. Half of our participants receive an introductory programming lesson in which we explain a variable as a box, while the other half of participants receive the explanation of a variable as being a label. They are subsequently questioned about their understanding of variables. Our results show that, for the simple questions involving one assignment, the box group performs better. However, for questions involving the misconception - with two consecutive assignment statements - the label group outperforms the box group. This however primarily occurs when considering variables of type string, for integers subjects interpret the statements as numeric values to be added.","Misconceptions; Programming education; Scratch","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Software Engineering","","",""
"uuid:f9467d4d-6f95-47df-baba-7443cf4c237a","http://resolver.tudelft.nl/uuid:f9467d4d-6f95-47df-baba-7443cf4c237a","Toward complete oral cavity cancer resection using a handheld diffuse reflectance spectroscopy probe","Brouwer de Koning, Susan G. (Antoni van Leeuwenhoek Ziekenhuis); Baltussen, Elisabeth J.M. (Antoni van Leeuwenhoek Ziekenhuis); Karakullukcu, M. Baris (Antoni van Leeuwenhoek Ziekenhuis); Dashtbozorg, Behdad (Netherlands Cancer Institute); Smit, Laura A. (Antoni van Leeuwenhoek Ziekenhuis); Dirven, Richard (Antoni van Leeuwenhoek Ziekenhuis); Hendriks, B.H.W. (TU Delft Medical Instruments & Bio-Inspired Technology; Philips Research); Sterenborg, Henricus J.C.M. (Antoni van Leeuwenhoek Ziekenhuis; Amsterdam UMC); Ruers, Theo J.M. (University of Twente; Antoni van Leeuwenhoek Ziekenhuis)","","2018","This ex-vivo study evaluates the feasibility of diffuse reflectance spectroscopy (DRS) for discriminating tumor from healthy tissue, with the aim to develop a technology that can assess resection margins for the presence of tumor cells during oral cavity cancer surgery. Diffuse reflectance spectra were acquired on fresh surgical specimens from 28 patients with oral cavity squamous cell carcinoma. The spectra (400 to 1600 nm) were detected after illuminating tissue with a source fiber at 0.3-, 0.7-, 1.0-, and 2.0-mm distances from a detection fiber, obtaining spectral information from different sampling depths. The spectra were correlated with histopathology. A total of 76 spectra were obtained from tumor tissue and 110 spectra from healthy muscle tissue. The first- and second-order derivatives of the spectra were calculated and a classification algorithm was developed using fivefold cross validation with a linear support vector machine. The best results were obtained by the reflectance measured with a 1-mm source-detector distance (sensitivity, specificity, and accuracy are 89%, 82%, and 86%, respectively). DRS can accurately discriminate tumor from healthy tissue in an ex-vivo setting using a 1-mm source-detector distance. Accurate validation methods are warranted for larger sampling depths to allow for guidance during oral cavity cancer excision.","diffuse reflectance spectroscopy; linear support vector machine; machine learning; oral cavity cancer; resection margin assessment; tissue recognition","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:a323ed19-405d-49a7-9184-3479120a6ee1","http://resolver.tudelft.nl/uuid:a323ed19-405d-49a7-9184-3479120a6ee1","Additive manufacturing of non-assembly mechanisms","Cuellar Lopez, J.S. (TU Delft Medical Instruments & Bio-Inspired Technology); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Plettenburg, D.H. (TU Delft Biomechatronics & Human-Machine Control); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2018","Fabrication of complex and multi-articulated mechanisms is often seen as a time consuming and demanding process. The development of functional multi-articulated mechanisms that could be fabricated in a single step without the need for post-manufacturing assembly is therefore very attractive. Additive manufacturing (AM) has been pointed out as a feasible solution due to its numerous advantages and high versatility in comparison to other manufacturing techniques. Nevertheless, AM techniques also present different shortcomings that limit the complexity of the mechanism for single step fabrication. Here, we review the applications of AM techniques in fabrication of non-assembly multi-articulated mechanisms and highlight the involved challenges, thereby providing a perspective regarding the advantages and limitations of current AM techniques for production of complex mechanical devices. The paper starts off with basic joint elements in rigid-body and compliant configurations and proceeds with presenting an overview of multiple arrangements of joints and assemblies with embedded mechanical components. For every case of non-assembly fabrication, the limitations of the applicable AM processes are presented and further discussed. This work concludes with a discussion of the major shortcomings found in current non-assembly mechanisms fabricated by AM and recommending alternative techniques and future developments on AM.","3D printing; Additive manufacturing; Mechanism design; Non-assembly mechanisms","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.","","2018-08-21","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:5367376b-885f-4d53-af7b-cc4fe4582e8f","http://resolver.tudelft.nl/uuid:5367376b-885f-4d53-af7b-cc4fe4582e8f","Design of a novel miniature breast biopsy needle for ductoscopy","Sakes, A. (TU Delft Medical Instruments & Bio-Inspired Technology); Snaar, Kevin (Student TU Delft); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Witkamp, Arjen J. (University Medical Center Utrecht); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2018","Background. The majority of the benign and malignant lesions in the breast arise from the ductal epithelium and terminal ductlobular unit. A minimally invasive procedure called ductoscopy is able to visualize these lesions as it inspects the ductal epithelium using a small micro-endoscope. Unfortunately, it is currently challenging to obtain a tissue sample during ductoscopy and reach the most distal duct. Methods. In this study we have, therefore, developed a novel miniature (∅1.2 mm) biopsy needle that can be used during ductoscopy. This biopsy needle consists of two coaxial counter-rotating hollow blades with a distal cutout to resect lesions from the ductal wall. Three cutouts were manufactured resulting in a beveled, straight, and reverse-beveled blade. The blades were actuated using a novel mechanism containing two helical paths that allows for the counter-rotating motion of the blades at different velocities. In a proof-of-principle experiment, the performance of the biopsy needle was evaluated using a polymeric duct model and gelatin tissue phantom. Results. During the experiment, the straight and reverse-beveled blades were able to obtain a sufficiently large tissue sample for histopathological examination. Based on these promising results, a second experiment was performed in which the micro-endoscope was integrated in the needle and we were able to take a biopsy from a chicken breast. Conclusions. In a future clinical instrument, the biopsy needle will be miniaturized and optimized to allow for an efficient, safe, and effective intraductal biopsy procedure without the need for an invasive excisional biopsy procedure.","biomedical equipment; biopsy needle; ductoscopy; medical device 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.","","2018-09-28","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:e1b832d5-04c3-4cbc-a588-16a961034416","http://resolver.tudelft.nl/uuid:e1b832d5-04c3-4cbc-a588-16a961034416","The Political Morphology of Drainage—How Gully Formation Links to State Formation in the Choke Mountains of Ethiopia","Smit, H. (TU Delft Water Resources; IHE Delft Institute for Water Education); Muche, Rahel (IHE Delft Institute for Water Education; Addis Ababa University); Ahlers, Rhodante (Independent researcher); van der Zaag, P. (TU Delft Water Resources; IHE Delft Institute for Water Education)","","2017","To understand why soil erosion is persistent despite three decades of massive investments in soil conservation, this paper explores how drainage and soil conservation change a hill slope in the Choke Mountains. By paying close attention to the practices that reshape the hill, we account for the active roles of people and material flows in shaping their identities, forms, and power relations. Social relations can be read in the landscape as their material outcomes are literally scoured into the hill slope. Such a material reading of Ethiopia's “developmental state” reveals three issues: First, drainage and soil conservation practices are configured by particular historical regimes of land distribution and rent appropriation. Second, the power of the Ethiopian government's model of the developmental state derives from the exploitation of this configuration by a new coalition of landholders and government officials. Government officials mobilize landholders to construct terraces in exchange for government support in conflicts over land and input distribution. When the terraces create obstructions that can trigger flooding, landowners convert them into drains and divert drainage flows to plots sharecropped by landless families. Consequently, the yearly mobilization for terrace construction does not halt soil erosion but further aggravates it. This continues because the performance of this yearly ritual affirms the authority of landholders and government agents. Third, landless families which fail to live up to the model of the “farmer interested in soil conservation” have created a competing “trader model” with its own institutions. The denial of their non-farmer identities by landholders and officials fuels generational conflicts over drainage which deepen the fractures in the hill and pose a challenge to government authority. Land degradation thus embodies both the powers and the limits of the developmental state.","Africa; drainage; Ethiopia; identity; land degradation; political ecology","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:2fdef90e-96f1-42da-93fc-2f65245f8753","http://resolver.tudelft.nl/uuid:2fdef90e-96f1-42da-93fc-2f65245f8753","Efficient non-hydrostatic modelling of 3D wave-induced currents using a subgrid approach","Rijnsdorp, D.P. (TU Delft Environmental Fluid Mechanics; University of Western Australia; Centre for Offshore Foundation Systems); Smit, Pieter B. (Spoondrift Technologies, Inc.); Zijlema, Marcel (TU Delft Environmental Fluid Mechanics); Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics)","","2017","Wave-induced currents are an ubiquitous feature in coastal waters that can spread material over the surf zone and the inner shelf. These currents are typically under resolved in non-hydrostatic wave-flow models due to computational constraints. Specifically, the low vertical resolutions adequate to describe the wave dynamics – and required to feasibly compute at the scales of a field site – are too coarse to account for the relevant details of the three-dimensional (3D) flow field. To describe the relevant dynamics of both wave and currents, while retaining a model framework that can be applied at field scales, we propose a two grid approach to solve the governing equations. With this approach, the vertical accelerations and non-hydrostatic pressures are resolved on a relatively coarse vertical grid (which is sufficient to accurately resolve the wave dynamics), whereas the horizontal velocities and turbulent stresses are resolved on a much finer subgrid (of which the resolution is dictated by the vertical scale of the mean flows). This approach ensures that the discrete pressure Poisson equation – the solution of which dominates the computational effort – is evaluated on the coarse grid scale, thereby greatly improving efficiency, while providing a fine vertical resolution to resolve the vertical variation of the mean flow. This work presents the general methodology, and discusses the numerical implementation in the SWASH wave-flow model. Model predictions are compared with observations of three flume experiments to demonstrate that the subgrid approach captures both the nearshore evolution of the waves, and the wave-induced flows like the undertow profile and longshore current. The accuracy of the subgrid predictions is comparable to fully resolved 3D simulations – but at much reduced computational costs. The findings of this work thereby demonstrate that the subgrid approach has the potential to make 3D non-hydrostatic simulations feasible at the scale of a realistic coastal region.","Nearshore circulation; Non-hydrostatic modelling; Subgrid; SWASH; Wave breaking; Wave-induced currents","en","journal article","","","","","","","","2019-07-04","","","Environmental Fluid Mechanics","","",""
"uuid:a29ccc13-6e1c-4919-ba0a-9ccbd599d7ef","http://resolver.tudelft.nl/uuid:a29ccc13-6e1c-4919-ba0a-9ccbd599d7ef","Effect of Interfacial Polarization and Water Absorption on the Dielectric Properties of Epoxy-Nanocomposites","Marx, Philipp (Polymer Competence Center Leoben; Montanuniversität Leoben); Wanner, Andrea (Polymer Competence Center Leoben; Montanuniversität Leoben); Zhang, Zucong (Polymer Competence Center Leoben); Jin, H. (TU Delft DC systems, Energy conversion & Storage); Tsekmes, I.A. (TU Delft DC systems, Energy conversion & Storage; Montanuniversität Leoben); Smit, J.J. (TU Delft EEMS - General); Kern, Wolfgang (Polymer Competence Center Leoben; Montan University of Leoben); Wiesbrock, Frank (Polymer Competence Center Leoben)","","2017","Five types of nanofillers, namely, silica, surface-silylated silica, alumina, surface-silylated alumina, and boron nitride, were tested in this study. Nanocomposites composed of an epoxy/amine resin and one of the five types of nanoparticles were tested as dielectrics with a focus on (i) the surface functionalization of the nanoparticles and (ii) the water absorption by the materials. The dispersability of the nanoparticles in the resin correlated with the composition (OH content) of their surfaces. The interfacial polarization of the thoroughly dried samples was found to increase at lowered frequencies and increased temperatures. The β relaxation, unlike the interfacial polarization, was not significantly increased at elevated temperatures (below the glass-transition temperature). Upon the absorption of water under ambient conditions, the interfacial polarization increased significantly, and the insulating properties decreased or even deteriorated. This effect was most pronounced in the nanocomposite containing silica, and occurred as well in the nanocomposites containing silylated silica or non-functionalized alumina. The alternating current (AC) breakdown strength of all specimens was in the range of 30 to 35 kV·mm−1. In direct current (DC) breakdown tests, the epoxy resin exhibited the lowest strength of 110 kV·mm−1; the nanocomposite containing surface-silylated alumina had a strength of 170 kV·mm−1. In summary, water absorption had the most relevant impact on the dielectric properties of nanocomposites containing nanoparticles, the surfaces of which interacted with the water molecules. Nanocomposites containing silylated alumina particles or boron nitride showed the best dielectric properties in this study.","epoxy resins; nanoparticles; surface functionalization; silylating agent; water uptake; permittivity; loss factor; interfacial polarization; thermal conductivity","en","contribution to periodical","","","","","","Special Issue ""Polymer Nanocomposites""","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:d3b775c2-8406-43a7-9775-f3b107278eec","http://resolver.tudelft.nl/uuid:d3b775c2-8406-43a7-9775-f3b107278eec","Improving training of laparoscopic tissue manipulation skills using various visual force feedback types","Smit, Daan; Spruit, Edward; Dankelman, J. (TU Delft Medical Instruments & Bio-Inspired Technology); Tuijthof, G.J.M. (TU Delft Medical Instruments & Bio-Inspired Technology); Hamming, J; Horeman, T. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2017","Background Visual force feedback allows trainees to learn laparoscopic tissue manipulation skills. The aim of this experimental study was to find the most efficient visual force feedback method to acquire these skills. Retention and transfer validity to an untrained task were assessed. Methods Medical students without prior experience in laparoscopy were randomized in three groups: Constant Force Feedback (CFF) (N = 17), Bandwidth Force Feedback (BFF) (N = 16) and Fade-in Force Feedback (N = 18). All participants performed a pretest, training, post-test and follow-up test. The study involved two dissimilar tissue manipulation tasks, one for training and one to assess transferability. Participants performed six trials of the training task. A force platform was used to record several force parameters. Results A paired-sample t test showed overall lower force parameter outcomes in the post-test compared to the pretest (p < .001). A week later, the force parameter outcomes were still significantly lower than found in the pretest (p < .005). Participants also performed the transfer task in the post-test (p < .02) and follow-up (p < .05) test with lower force parameter outcomes compared to the pretest. A one-way MANOVA indicated that in the post-test the CFF group applied 50 % less Mean Absolute Nonzero Force (p = .005) than the BFF group. Conclusion All visual force feedback methods showed to be effective in decreasing tissue manipulation force as no major differences were found between groups in the post and follow-up trials. The BFF method is preferred for it respects individual progress and minimizes distraction.","visual feedback; learning curve; laparoscopy; tissue manipulation skills; force; hybrid box trainer","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:267892d9-cb90-49a3-bdaa-59fa9772413f","http://resolver.tudelft.nl/uuid:267892d9-cb90-49a3-bdaa-59fa9772413f","Insulation Reliability of Superconductive Cables","Ross, Robert (TU Delft DC systems, Energy conversion & Storage; TenneT TSO B.V.); Gholizad, B. (TU Delft DC systems, Energy conversion & Storage); Koopmans, Gerben (IWO (Inst. for Science & Development / Inst. voor Wetenschap & Ontwikkeling)); Mousavi Gargari, Shima (TenneT TSO B.V.); Smit, J.J. (TU Delft EEMS - General; IWO (Inst. for Science & Development / Inst. voor Wetenschap & Ontwikkeling)); Ghaffarian Niasar, M. (TU Delft DC systems, Energy conversion & Storage); Meijer, Cees G. (RH Marine); Bucurenciu, Ana-Maria (RH Marine)","","2017","High current capability, good integration in urban area and zero external magnetic field are advantages of HTS cables that make them interesting for implementation in the Netherlands. So far experience with HTS cable projects is good, but still limited. Yet there is a need for a proper testing practice. Due to limited operational experience, various aspects remain to be studied. This paper focuses on electrical testing of electrical insulation, the application of power laws and the length effect. These issues are yet to be resolved, but the paper discusses their background and uncertainties. This may give direction to the ongoing studies in order to assure quality of HTS.","Superconductivity; Power cables; Dielectrics; Testing; Power law; Materials","en","conference paper","IEEE","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:7cb7bc6d-36f1-406a-86b6-38f64d133174","http://resolver.tudelft.nl/uuid:7cb7bc6d-36f1-406a-86b6-38f64d133174","3D-printed upper limb prostheses: a review","ten Kate, J; Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2017","Goal: This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users. Methods: A review was performed using Scopus, Web of Science and websites related to 3D-printing. Quantitative information on the mechanical and kinematic specifications and 3D-printing technology used was extracted from the papers and websites. Results: The overview (58 devices) provides the general specifications, the mechanical and kinematic specifications of the devices and information regarding the 3D-printing technology used for hands. The overview shows prostheses for all different upper limb amputation levels with different types of control and a maximum material cost of $500. Conclusion: A large range of various prostheses have been 3D-printed, of which the majority are used by children. Evidence with respect to the user acceptance, functionality and durability of the 3D-printed hands is lacking. Contrary to what is often claimed, 3D-printing is not necessarily cheap, e.g., injection moulding can be cheaper. Conversely, 3D-printing provides a promising possibility for individualization, e.g., personalized socket, colour, shape and size, without the need for adjusting the production machine.Implications for rehabilitation Upper limb deficiency is a condition in which a part of the upper limb is missing as a result of a congenital limb deficiency of as a result of an amputation. A prosthetic hand can restore some of the functions of a missing limb and help the user in performing activities of daily living. Using 3D-printing technology is one of the solutions to manufacture hand prostheses. This overview provides information about the general, mechanical and kinematic specifications of all the devices and it provides the information about the 3D-printing technology used to print the hands.","3D-printing; hand; prostheses; specifications; upper limb","en","journal article","","","","","","Accepted Author Manuscript","","2018-02-02","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:754b2e00-0e88-411e-8c85-61f3f45238fe","http://resolver.tudelft.nl/uuid:754b2e00-0e88-411e-8c85-61f3f45238fe","Exploring challenges and solutions for container transportation using rail: A modelling and simulation gaming study","Kurapati, S. (TU Delft Policy Analysis); Kourounioti, I. (TU Delft Transport and Logistics); Lukosch, H.K. (TU Delft Policy Analysis); Tavasszy, Lorant (TU Delft Transport and Logistics); Verbraeck, A. (TU Delft Policy Analysis); van Veen, A.J. (TU Delft Organisation & Governance); van Nuland, B. (The Barn); Smit, Thijs (TNO)","","2017","Rail is a cost-effective and environment friendly freight transport modality when used efficiently. Stakeholders around Dutch ports are discouraged to choose rail due to uncertain train schedules and the dispersed nature of freight flows across terminals in the port. To understand the challenges and opportunities of freight transport using rail, we used a combined approach of modelling and simulation gaming as participative research method. In addition to a simulation game, we developed a metamodel to simulate all possible choices of the players in the game. We designed and executed simulation gaming sessions with professionals and students. Within these sessions, we collected data in the form of surveys and in-game observations on the behaviour of the players. We compared and contrasted the results of the metamodel with those of the gaming sessions. The main contribution of the research is the provision of a deep insight into the challenges and opportunities offered by efficient transportation of containers using rail. The combined approach allows us to assess the effectiveness of various incentives to consolidate freight, promote intermodal transportation and to encourage the development of efficient services for rail freight transport.","freight containers; goods distribution; railways; sea ports; transportation; Dutch ports; container transportation; freight flows; freight transport; game observations; rail; stakeholders; uncertain train schedules; Containers; Data models; Games; Logistics; Rails; Stakeholders; Transportation; container terminal; rail bundling; rail cargo challenge; serious game; simulation model","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.","","2018-02-18","","","Policy Analysis","","",""
"uuid:b01f4a9e-5dda-4ab9-a609-0eca46cb4358","http://resolver.tudelft.nl/uuid:b01f4a9e-5dda-4ab9-a609-0eca46cb4358","The MemoSlide: An explorative study into a novel mechanical follow-the-leader mechanism","Henselmans, P.W.J. (TU Delft Medical Instruments & Bio-Inspired Technology); Gottenbos, Stefan (Student TU Delft); Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2017","Follow-the-leader propagation allows for the insertion of flexible surgical instruments along curved paths, reducing the access required for natural orifice transluminal endoscopic surgery. Currently, the most promising follow-the-leader instruments use the alternating memory method containing two mechanical memory-banks for controlling the motion of the flexible shaft, which reduces the number of actuators to a minimum. These instruments do, however, require concentric structures inside the shaft, limiting its miniaturization. The goal of this research was, therefore, to develop a mechanism conforming the principles of the alternating memory method that could be located at the controller-side instead of inside the shaft of the instrument, which is positioned outside the patient and is therefore less restricted in size. First, the three-dimensional motion of the shaft was decoupled into movement in a horizontal and vertical plane, which allowed for a relatively simple planar alternating memory mechanism design for controlling planar follow-the-leader motion. Next, the planar movement of the alternating memory mechanism was discretized, increasing its resilience to errors. The resulting alternating memory mechanism was incorporated and tested in a proof-of-concept prototype called the MemoSlide. This prototype does not include a flexible shaft, but was fully focused on proving the function of the alternating memory mechanism. Evaluation of the MemoSlide shows the mechanism to work very well, being able to transfer any planar path that lays within its physical boundaries along the body of the mechanism without accumulating errors.","follow-the-leader; minimally invasive surgery; Natural orifices transluminal endoscopic surgery; pathway surgery; surgical instruments","en","journal article","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:d588be69-fe96-4848-b6e1-7538e8711797","http://resolver.tudelft.nl/uuid:d588be69-fe96-4848-b6e1-7538e8711797","Conceptual models for short-eccentricity-scale climate control on peat formation in a lower Palaeocene fluvial system, north-eastern Montana (USA)","Noorbergen, Lars J. (Vrije Universiteit Amsterdam); Abels, H.A. (TU Delft Applied Geology); Hilgen, Frederik J. (Universiteit Utrecht); Robson, Brittany E. (Royal Holloway University of London); de Jong, Edwin (Universiteit Utrecht); Dekkers, Mark J. (Universiteit Utrecht); Krijgsman, Wout (Universiteit Utrecht); Smit, Jan (Vrije Universiteit Amsterdam); Collinson, Margaret E. (Royal Holloway University of London); Kuiper, Klaudia F. (Vrije Universiteit Amsterdam)","","2017","Fluvial systems in which peat formation occurs are typified by autogenic processes such as river meandering, crevasse splaying and channel avulsion. Nevertheless, autogenic processes cannot satisfactorily explain the repetitive nature and lateral continuity of many coal seams (compacted peats). The fluvial lower Palaeocene Tullock Member of the Fort Union Formation (Western Interior Williston Basin; Montana, USA) contains lignite rank coal seams that are traceable over distances of several kilometres. This sequence is used to test the hypothesis that peat formation in the fluvial system was controlled by orbitally forced climate change interacting with autogenic processes. Major successions are documented with an average thickness of 6·8 m consisting of ca 6 m thick intervals of channel and overbank deposits overlain by ca 1 m thick coal seam units. These major coal seams locally split and merge. Time-stratigraphic correlation, using a Cretaceous-Palaeogene boundary event horizon, several distinctive volcanic ash-fall layers, and the C29r/C29n magnetic polarity reversal, shows consistent lateral recurrence of seven successive major successions along a 10 km wide fence panel perpendicular to east/south-east palaeo-flow. The stratigraphic pattern, complemented by stratigraphic age control and cyclostratigraphic tests, suggests that the major peat-forming phases, resulting in major coal seams, were driven by 100 kyr eccentricity-related climate cycles. Two distinct conceptual models were developed, both based on the hypothesis that the major peat-forming phases ended when enhanced seasonal contrast, at times of minimum precession during increasing eccentricity, intensified mire degradation and flooding. In model 1, orbitally forced climate change controls the timing of peat compaction, leading to enhancement of autogenic channel avulsions. In model 2, orbitally forced climate change controls upstream sediment supply and clastic influx determining the persistence of peat-forming conditions. At the scale of the major successions, model 2 is supported because interfingering channel sandstones do not interrupt lateral continuity of major coal seams.","Conceptual model; Fluvial system; Lignite rank coal; North-eastern Montana; Orbitally forced climate change; Palaeocene; Peat formation; Time-stratigraphic correlation","en","journal article","","","","","","","","","","","Applied Geology","","",""
"uuid:f9f7da8f-3639-4b04-94f3-14be8d41a90d","http://resolver.tudelft.nl/uuid:f9f7da8f-3639-4b04-94f3-14be8d41a90d","Passive prosthetic hands and tools: A literature review","Maat (student), B.B.; Smit, G. (TU Delft Medical Instruments & Bio-Inspired Technology); Plettenburg, D.H. (TU Delft Biomechatronics & Human-Machine Control); Breedveld, P. (TU Delft Medical Instruments & Bio-Inspired Technology)","","2017","The group of passive prostheses consists of prosthetic hands and prosthetic tools. These can either be static or adjustable. Limited research and development on passive prostheses has been performed although many people use these prosthesis types. Although some publications describe passive prostheses, no recent review of the peer-reviewed literature on passive prostheses is available.","Upper limb; prosthesis; passive; cosmetic; hand; tool; adaption; static; adjustable","en","review","","","","","","","","","","","Medical Instruments & Bio-Inspired Technology","","",""
"uuid:4fcca547-349e-4095-a3a3-56f7f5b804d6","http://resolver.tudelft.nl/uuid:4fcca547-349e-4095-a3a3-56f7f5b804d6","Monolithic photonic integration technology platform and devices at wavelengths beyond 2 μm for gas spectroscopy applications","Latkowski, S (Eindhoven University of Technology); Van Veldhoven, P. J. (Eindhoven University of Technology); Hänsel, A. (TU Delft ImPhys/Optics); D'Agostino, D. (Eindhoven University of Technology); Rabbani-Haghighi, H. (Eindhoven University of Technology); Docter, B. (EFFECT Photonics B.V.); Bhattacharya, N. (TU Delft ImPhys/Optics); Thijs, P. J A (Eindhoven University of Technology); Ambrosius, H. P M M (Eindhoven University of Technology); Smit, M (Eindhoven University of Technology); Williams, KA (Eindhoven University of Technology); Bente, E.A.J.M. (Eindhoven University of Technology)","Garcia-Blanco, Sonia M. (editor); Nunzi Conti, Gualtiero (editor)","2017","In this paper a generic monolithic photonic integration technology platform and tunable laser devices for gas sensing applications at 2 μm will be presented. The basic set of long wavelength optical functions which is fundamental for a generic photonic integration approach is realized using planar, but-joint, active-passive integration on indium phosphide substrate with active components based on strained InGaAs quantum wells. Using this limited set of basic building blocks a novel geometry, widely tunable laser source was designed and fabricated within the first long wavelength multiproject wafer run. The fabricated laser operates around 2027 nm, covers a record tuning range of 31 nm and is successfully employed in absorption measurements of carbon dioxide. These results demonstrate a fully functional long wavelength photonic integrated circuit that operates at these wavelengths. Moreover, the process steps and material system used for the long wavelength technology are almost identical to the ones which are used in the technology process at 1.5μm which makes it straightforward and hassle-free to transfer to the photonic foundries with existing fabrication lines. The changes from the 1550 nm technology and the trade-offs made in the building block design and layer stack will be discussed.","Gas spectroscopy; Photonic integrated circuits; Semiconductor laser; Tunable laser","en","conference paper","SPIE","","","","","","","","","","ImPhys/Optics","","",""
"uuid:640598d3-099b-4968-8461-baca9cf42b71","http://resolver.tudelft.nl/uuid:640598d3-099b-4968-8461-baca9cf42b71","Monolithically integrated widely tunable laser source operating at 2 μm","Latkowski, S (Eindhoven University of Technology); Hänsel, A. (TU Delft ImPhys/Optics); Van Veldhoven, P. J. (Eindhoven University of Technology); D’Agostino, D. (Eindhoven University of Technology); Rabbani-Haghighi, H. (Eindhoven University of Technology); Docter, B. (EFFECT Photonics B.V.); Bhattacharya, N. (TU Delft ImPhys/Optics); Thijs, P. J A (Eindhoven University of Technology); Ambrosius, H. P M M (Eindhoven University of Technology); Smit, M (Eindhoven University of Technology); Bente, E.A.J.M. (Eindhoven University of Technology)","","2016","We present a widely tunable extended cavity ring laser operating at 2 μm that is monolithically integrated on an indium phosphide substrate. The photonic integrated circuit is designed and fabricated within a multiproject wafer run using a generic integration technology platform. The laser features an intracavity tuning mechanism based on nested asymmetric Mach-Zehnder interferometers with voltage controlled electro-refractive modulators. The laser operates in a single-mode regime and is tunable over the recorded wavelength range of 31 nm, spanning from 2011 to 2042 nm. Its capability for high-resolution scanning is demonstrated in a single-line spectroscopy experiment using a carbon dioxide reference cell.","Laser sensors; Lasers, tunable; Photonic integrated circuits; Semiconductor lasers; Spectroscopy","en","journal article","","","","","","","","","","","ImPhys/Optics","","",""
"uuid:b065ea24-0fb8-4cab-b427-9612ae6a2113","http://resolver.tudelft.nl/uuid:b065ea24-0fb8-4cab-b427-9612ae6a2113","The Virtual Surgical Pelvis: Anatomy Visualization for Education and Surgical Planning","Smit, N.N. (TU Delft Computer Graphics and Visualisation)","Eisemann, E. (promotor); de Ruiter, M.C. (promotor); Vilanova Bartroli, A. (copromotor); Delft University of Technology (degree granting institution)","2016","This thesis deals with visualizing anatomical data for medical education and surgical planning purposes. To this end, we have developed a detailed virtual atlas, the Virtual Surgical Pelvis (VSP),which unifies surgically relevant knowledge on pelvic anatomy. We provide methods to share the knowledge contained in the VSP for educational purposes, and to visualize the VSP in the context of individual patients for pre-operative planning purposes.
Chapter 2 deals with a representation developed to unify spatial and non-spatial
anatomical knowledge. Via this representation, it is possible to store, access and visualize these heterogeneous datasets through a shared coordinate system. This allows us to construct the VSP atlas, a process which we describe in detail in Chapter 3, where we also detail the application potential of the VSP. We present several examples of the VSP mapped to clinical pre-operative MRI scans, as examples of how the VSP can be used to enrich clinical data with surgically relevant information that is not available from the scans themselves.
To share the VSP for educational purposes, we present an online tool, the Online Anatomical Human (OAH) in Chapter 4. OAH runs directly in the browser and can be used to explore the complex relation between 2D and 3D anatomy. Furthermore, annotations can be added directly on the 3D structures for quizzing purposes, or to enrich the VSP further with annotations performed by experts. The OAH was successfully deployed in aMassiveOpenOnline Course (MOOC), where thousands of studentsworldwide used the application to study pelvic anatomy.
While the VSP is based on multiple datasets, it does not include all potential topological anatomical variations in branching structures such as vessels and nerves. Illustrations and text are traditionally used by medical specialists to study these variations, but it is difficult to compare complex variations in such illustrations. Therefore, in Chapter 5 we present an interactive visualization application for anatomical variations, which allows the user to compare and explore variations of branching structures interactively for educational purposes. With methods inspired by graph theory, users can intuitively select groups of variations, based on a similarity measure, and compare local differences.
In Chapter 6, we present a state-of-the-art report on multimodal medical visualization. We describe the basics of medical image acquisition, and the clinical workflow for dealing with such data. We discuss suitable rendering and visualization techniques appropriate for rendering multiple modalities. The core contribution of this work is a taxonomy based on the multimodal medical visualization applications so far, the visualization techniques they employ, and the medical domain context. Additionally, we provide an outlook on open problems and potential future research directions.
To make the VSP patient-specific and to enrich the VSP with more datasets, registration is needed. Unfortunately, current registration software is often difficult to use for non-medical-imaging-experts. In Chapter 7 we present a new registration application, RegistrationShop, that allows user to register 3D medical image datasets based on 3D visualizations and simple interactive transformation tools. Based on real-time visual feedback via comparative visualization techniques, users can inspect the current registration result and iteratively improve the alignment. Besides basic interactive transformation tools, we propose a novel way of placing corresponding landmark-pairs in 3D volumes.
After combining the VSP atlas with patient-specific pre-operative MRI scans, we visualize the results in an interactive application for surgical planning aimed at pelvic oncological procedures, entitled PelVis, which is described in Chapter 8. We present visualization methods to represent context, target, and risk structures for surgical planning of the Total Mesorectal Excision (TME) procedure. We employ distance-based and occlusion management techniques to represent the patient-specific pathology and anatomy. Furthermore, we visualize the confidence in the registration outcome in relation to the distance of the target structure to the risk zones.
The research described in this thesis was supported by the Dutch Technology Foundation STW via project 10903: “High-definition Atlas-based surgical planning for Pelvic Surgery”.","medical visualization; anatomy; education; surgical planning","en","doctoral thesis","","978-94-6186-719-3","","","","","","","","","Computer Graphics and Visualisation","","",""
"uuid:478725ee-cfce-4c89-add4-8d9778d81ddc","http://resolver.tudelft.nl/uuid:478725ee-cfce-4c89-add4-8d9778d81ddc","The influence of radiative transfer on the turbulent flow inside solar absorbers operating with supercritical CO2","Pecnik, Rene (TU Delft Energy Technology); Smit, S.H.H.J. (Student TU Delft); Patel, A. (TU Delft Energy Technology); Roekaerts, D.J.E.M. (TU Delft Fluid Mechanics)","","2016","In this paper we investigate and compare two dierent solar receiver technologies for concentrated solar power plants operating with supercritical CO2. The rst receiver is based on conventional surface absorbers, while the second receiver is based on an innovative idea to use volumetric receivers where sunlight is transmitted through a transparent pipe and directly absorbed by nanoparticles
dispersed in supercritical CO2. The optical properties of the nanoparticles and the CO2 at high pressures and temperatures have been rst estimated and then used in a Navier-Stokes solver that has been coupled to a radiative transfer solver. The results indicate that for temperatures up to 700C the volumetric receiver achieves thermal collector eciencies up to 65% as compared to
surface receivers with 50%.","","en","conference paper","","","","","","","","","","","Energy Technology","","",""
"uuid:ee5b2542-64a3-4307-8b99-f61690ee523b","http://resolver.tudelft.nl/uuid:ee5b2542-64a3-4307-8b99-f61690ee523b","Novel widely tunable monolithically integrated laser source","Latkowski, S.; Hansel, A.; Bhattacharya, N.; De Vries, T.; Augustin, L.; Williams, K.; Smit, M.; Bente, E.","","2015","","semiconductor laser; tunable laser; photonic integrated circuit","en","journal article","IEEE","","","","","","","","Applied Sciences","Imaging Physics","","","",""
"uuid:6ac64ab7-73a8-4b91-90b1-b1632f960ad9","http://resolver.tudelft.nl/uuid:6ac64ab7-73a8-4b91-90b1-b1632f960ad9","Crosslinked Poly(2-oxazoline)s as “Green” Materials for Electronic Applications","Fimberger, M.; Tsekmes, I.A.; Kochetov, R.; Smit, J.J.; Wiesbrock, F.","","2015","Poly(2-nonyl-2-oxazoline)80-stat-poly(2-dec-9?-enyl-2-oxazoline)20 and poly(2-dec-9?-enyl-2-oxazoline)100 can be synthesized from the cationic ring-opening polymerization of monomers that can be derived from fatty acids from renewable resources. These (co)poly(2-oxazoline)s can be crosslinked with di- and trifunctional mercapto compounds using the UV-induced thiol-ene reaction. The complex permittivity of the corresponding networks increases with the temperature and decreases with the network density. In a frequency range from 10?2 to 106 Hz and at temperatures ranging from ?20 to 40 °C, the changes of the real part of the complex permittivity as well as the loss factor can be explained by interfacial polarization within the material. At a temperature of 20 °C and a frequency of 50 Hz, the permittivity of the crosslinked (co)poly(2-oxazoline)s covers a range from 4.29 to 4.97, and the loss factors are in the range from 0.030 to 0.093. The electrical conductivities of these polymer networks span a range from 5 × 10?12 to 8 × 10?9 S/m, classifying these materials as medium insulators. Notably, the values for the permittivity, loss factor and conductivity of these copoly(2-oxazoline)s are in the same range as for polyamides, and, hence, these copoly(2-oxazoline)-based networks may be referred to as “green” alternatives for polyamides as insulators in electronic applications.","poly(2-oxazoline)s; crosslinked polymers; thiol-ene click chemistry; permittivity; loss factor; interfacial polarization; electrical conductivity","en","journal article","MDPI","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:78e2f054-a38b-4579-9837-d4b0ac98804a","http://resolver.tudelft.nl/uuid:78e2f054-a38b-4579-9837-d4b0ac98804a","Sessie 12 - Nieuwe verhoudingen in de Wijk: Verslag","Smit, V. (Haagse Hogeschool); Esser, G. (Mitros); Moret, A. (Woonstad Rotterdam); Bodaar, A. (Gemeente Den Haag); Hollaar, J. (Wijk Makelaar)","","2015","","","nl","conference paper","","","","","","","","","","","","","",""
"uuid:9fd7d56e-f36d-4154-b38e-6b3151b17868","http://resolver.tudelft.nl/uuid:9fd7d56e-f36d-4154-b38e-6b3151b17868","Understanding Lymphatic Drainage Pathways of the Ovaries to Predict Sites for Sentinel Nodes in Ovarian Cancer","Kleppe, M.; Kraima, A.C.; Kruitwagen, R.F.P.M.; Van Gorp, T.; Smit, N.N.; Van Munsteren, J.C.; De Ruiter, M.C.","","2015","Objective: In ovarian cancer, detection of sentinel nodes is an upcoming procedure. Perioperative determination of the patient’s sentinel node(s) might prevent a radical lymphadenectomy and associated morbidity. It is essential to understand the lymphatic drainage pathways of the ovaries, which are surprisingly up till now poorly investigated, to predict the anatomical regions where sentinel nodes can be found. We aimed to describe the lymphatic drainage pathways of the human ovaries including their compartmental fascia borders. Methods: A series of 3 human female fetuses and tissues samples from 1 human cadaveric specimen were studied. Immunohistochemical analysis was performed on paraffin-embedded transverse sections (8 or 10 µm) using antibodies against Lyve-1, S100, and [alpha]-smooth muscle actin to identify the lymphatic endothelium, Schwann, and smooth muscle cells, respectively. Three-dimensional reconstructions were created. Results: Two major and 1 minor lymphatic drainage pathways from the ovaries were detected. One pathway drained via the proper ligament of the ovaries (ovarian ligament) toward the lymph nodes in the obturator fossa and the internal iliac artery. Another pathway drained the ovaries via the suspensory ligament (infundibulopelvic ligament) toward the para-aortic and paracaval lymph nodes. A third minor pathway drained the ovaries via the round ligament to the inguinal lymph nodes. Lymph vessels draining the fallopian tube all followed the lymphatic drainage pathways of the ovaries. Conclusions: The lymphatic drainage pathways of the ovaries invariably run via the suspensory ligament (infundibulopelvic ligament) and the proper ligament of the ovaries (ovarian ligament), as well as through the round ligament of the uterus. Because ovarian cancer might spread lymphogenously via these routes, the sentinel node can be detected in the para-aortic and paracaval regions, obturator fossa and surrounding internal iliac arteries, and inguinal regions. These findings support the strategy of injecting tracers in both ovarian ligaments to identify sentinel nodes.","lymphatic drainage ovaries; sentinel node detection","en","journal article","IGCS and ESGO","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Intelligent Systems","","","",""
"uuid:58666c8b-4061-4062-8ccc-b50eb353c4c9","http://resolver.tudelft.nl/uuid:58666c8b-4061-4062-8ccc-b50eb353c4c9","Wrapping up your message: Sustainable storytelling through packaging","Wever, R.; Schermer, R.; Smit, L.; Vos, L.","","2015","Besides contributing to the actual sustainability performance of a product-packaging combination, packaging can also play a role in communicating about sustainability. Such green marketing aspects of packaging may either focus on the sustainability credentials of the packaging itself, or on the credentials of the product contained (or even the company or brand). Communication about sustainability can be explicit (in words or labels) or implicit (through materials, images and/or colours). The implicit form could be described as sustainable aesthetics. The explicit form can be presented either as factual information or in the form of stories. People engage more with stories than with factual information, as it allows for easier connections with previous experiences. Hence, storytelling makes for a compelling marketing tactic. Instead of telling a story yourself as a brand, enabling and encouraging your consumers to tell your story to their peers offers strong marketing potential as well. This paper will explore sustainable storytelling through packaging by reviewing the literature on storytelling within marketing, with a specific focus on sustainability and on packaging. Furthermore, two small empirical studies will be presented, followed by a design case study.","advertising; sustainability; storytelling; consumers","en","conference paper","International Association of Packaging Research Institutes","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:d2225a78-912d-4ecf-9263-8c1492287a34","http://resolver.tudelft.nl/uuid:d2225a78-912d-4ecf-9263-8c1492287a34","Stochastic modeling of coherent wave fields over variable depth","Smit, P.B.; Janssen, T.T.; Herbers, T.H.C.","","2015","Refractive focusing of swell waves can result in fast-scale variations in the wave statistics because of wave interference, which cannot be resolved by stochastic wave models based on the radiative transport equation. Quasi-coherent statistical theory does account for such statistical interferences and the associated wave inhomogeneities, but the theory has thus far been presented in a form that appears incompatible with models based on the radiative transfer equation (RTE). Moreover, the quasi-coherent theory has never been tested against field data, and it is not clear how the coherent information inherent to such models can be used for better understanding coastal wave and circulation dynamics. This study therefore revisits the derivation of quasi-coherent theory to formulate it into a radiative transport equation with a forcing term that accounts for the inhomogeneous part of the wave field. This paper shows how the model can be nested within (or otherwise used in conjunction with) quasi-homogeneous wave models based on the RTE. Through comparison to laboratory data, numerical simulations of a deterministic model, and field observations of waves propagating over a nearshore canyon head, the predictive capability of the model is validated. The authors discuss the interference patterns predicted by the model through evaluation of a complex cross-correlation function and highlight the differences with quasi-homogeneous predictions. These results show that quasi-coherent theory can extend models based on the RTE to resolve coherent interference patterns and standing wave features in coastal areas, which are believed to be important in nearshore circulation and sediment transport.","","en","journal article","American Meteorological Society","","","","","","","2015-10-31","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:8c2a26a9-b5c0-4cbc-a135-2108ad48e6a6","http://resolver.tudelft.nl/uuid:8c2a26a9-b5c0-4cbc-a135-2108ad48e6a6","The influence of interfaces and water uptake on the dielectric response of epoxy-cubic boron nitride composites","Tsekmes, I.A.; Morshuis, P.H.F.; Smit, J.J.; Kochetov, R.","","2015","In this study, epoxy-cubic boron nitride composites are fabricated, and their dielectric response is investigated. They exhibit the same trend as epoxy composites reinforced with other filler types. Thus, at low filler concentrations, they exhibit a lower relative permittivity than neat epoxy. As the fill grade further increases, the relative permittivity of the composites increases as well. It is suggested that two competing mechanisms, namely polymer re-organization and water uptake, mainly determine the dielectric response of epoxy composites. The former is related to the decrease while the latter to the increase of the relative permittivity. The experimental results clearly verify that water uptake strongly depends on the filler concentration and not only affects the dielectric response of epoxy composites but also it is one of the main mechanisms which dictate their dielectric behavior.","","en","journal article","Springer","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:f7a7ae94-fcae-4d5d-918f-3764b4b7ebf1","http://resolver.tudelft.nl/uuid:f7a7ae94-fcae-4d5d-918f-3764b4b7ebf1","Nonlinear infragravity–wave interactions on a gently sloping laboratory beach","De Bakker, A.T.M.; Herbers, T.H.C.; Smit, P.B.; Tissier, M.F.S.; Ruessink, B.G.","","2015","A high-resolution dataset of three irregular wave conditions collected on a gently sloping laboratory beach is analyzed to study nonlinear energy transfers involving infragravity frequencies. This study uses bispectral analysis to identify the dominant, nonlinear interactions and estimate energy transfers to investigate energy flows within the spectra. Energy flows are identified by dividing transfers into four types of triad interactions, with triads including one, two, or three infragravity–frequency components, and triad interactions solely between short-wave frequencies. In the shoaling zone, the energy transfers are generally from the spectral peak to its higher harmonics and to infragravity frequencies. While receiving net energy, infragravity waves participate in interactions that spread energy of the short-wave peaks to adjacent frequencies, thereby cre- ating a broader energy spectrum. In the short-wave surf zone, infragravity–infragravity interactions develop, and close to shore, they dominate the interactions. Nonlinear energy fluxes are compared to gradients in total energy flux and are observed to balance nearly completely. Overall, energy losses at both infragravity and short-wave frequencies can largely be explained by a cascade of nonlinear energy transfers to high frequencies (say, f . 1.5 Hz) where the energy is presumably dissipated. Infragravity–infragravity interactions seem to induce higher harmonics that allow for shape transformation of the infragravity wave to symmetric. The largest decrease in infragravity wave height occurs close to the shore, where infragravity–infragravity in- teractions dominate and where the infragravity wave is asymmetric, suggesting wave breaking to be the dominant mechanism of infragravity wave dissipation.","circulation/ dynamics; gravity waves; wave breaking; wave properties; wind waves","en","journal article","American Meteorological Society","","","","","","","2015-08-01","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:8ac50077-2862-4459-bb71-8078706bf436","http://resolver.tudelft.nl/uuid:8ac50077-2862-4459-bb71-8078706bf436","Investigation into the erosion velocity of grains subjected to a constant water flow","Smit, A.J.","Talmon, A.M. (mentor)","2015","","","","master thesis","","","","","","","","2100-09-29","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","","","",""
"uuid:adf45251-638a-4f97-90c4-22f1371b2d47","http://resolver.tudelft.nl/uuid:adf45251-638a-4f97-90c4-22f1371b2d47","Interactive Water Services: The WATERNOMICS Approach","Clifford, E.; Coakley, D.; Curry, E.; Degeler, V.; Costa, A.; Messervey, T.; Van Andel, S.J.; Van de Giesen, N.; Kouroupetroglou, C.; Mink, J.; Smit, S.","","2014","WATERNOMICS focuses on the development of ICT as an enabling technology to manage water as a resource, increase end-user conservation awareness and affect behavioral changes. Unique aspects of WATERNOMICS include personalized feedback about end-user water consumption, the development of systematic and standards-based water resource management systems, new sensor hardware developments, and the introduction of forecasting and fault detection diagnosis to the analysis of water consumption data. These services will be bundled into the WATERNOMICS Water Information Services Platform. This paper presents the overall architectural approach to WATERNOMICS and details the potential interactive services possible based on this novel platform.","interactive water services; decision support; gamification; linked data; fault detection","en","journal article","Elsevier","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:5238d48c-722c-4928-9ab8-b05ff771228e","http://resolver.tudelft.nl/uuid:5238d48c-722c-4928-9ab8-b05ff771228e","Upcoming Role of Condition Monitoring in Risk-Based Asset Management for the Power Sector","Mehairjan, R.P.Y.; Zhuang, Q.; Djairam, D.; Smit, J.J.","","2014","The electrical power sector is stimulated to evolve under the pressures of the energy transition, the deregulation of electricity markets and the introduction of intelligent grids. In general, engineers believe that technologies such as monitoring, control and diagnostic devices, can realize this evolvement smoothly. Unfortunately, the contributions of these emerging technologies to business strategies remain difficult to quantify in straightforward metrics. Consequently, decisions to invest on these technologies are still taken in an ad hoc manner. This is far from the risk-based approach commonly recommended for asset management (AM). The paper introduces risk-based management as a guiding principle for maintenance management. Then, the triple-level AM model (strategic, tactical and operational) as the foundation to define risk-based AM is described. Afterwards, two categories of risks, one triggered by technical stimuli and the other by non-technical stimuli are introduced. It is shown that the main challenge of managing risks with technical stimuli is to have the ability to understand the technical cause of failures, which is located at the operational level within the triple-level AM model. One method to quantitatively understand the technical cause of failures is by means of condition diagnostic and monitoring technologies. Therefore, the aim of this paper is to clarify the potential contribution of condition diagnostic and monitoring technologies to risk-based decision making for the power sector. This paper shows that, in practice, the implementation of condition diagnostic and monitoring technologies is mainly driven by purely technical asset based considerations without evaluating the contribution to, for instance, risks. This paper provides a list of aspects in which condition diagnostic and monitoring may contribute to risk evaluation with technical stimuli. The listed aspects (which are: (1) asset specific condition data, (2) timely condition data and (3) predictive condition data) can be regarded as input for the probability of failure and as influencing input for the consequence of failure, hence benefiting quantitative risk studies and AM activities (such as condition assessment/maintenance or replacement). Finally, these benefits can be evaluated afterwards in a risk-based AM planning stage, so that asset managers can justify investments on necessary technical improvements of condition monitoring systems.","asset management; maintenance; risk management; condition monitoring; electricity networks","en","conference paper","Springer","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:7b2e8a52-66ba-4704-b2a7-13ce23d80d7f","http://resolver.tudelft.nl/uuid:7b2e8a52-66ba-4704-b2a7-13ce23d80d7f","Sessie 6 Betaalbaar wonen in armoede - Beknopt verslag","Smit, V.","","2014","","huurachterstand; betaalbaarheid; armoede","nl","conference paper","","","","","","","","","","","","","",""
"uuid:b3db8267-1ab1-4bcf-b1dd-5871a0646363","http://resolver.tudelft.nl/uuid:b3db8267-1ab1-4bcf-b1dd-5871a0646363","Sessie 6 Betaalbaar wonen en armoede - Betaalbaar wonen en armoede","Smit, V.","","2014","","armoede; minimuminkomen","nl","conference paper","","","","","","","","","","","","","",""
"uuid:8ef44314-dfe4-4925-8d67-6445de07fb28","http://resolver.tudelft.nl/uuid:8ef44314-dfe4-4925-8d67-6445de07fb28","Mapping atmospheric aerosols with a citizen science network of smartphone spectropolarimeters","Snik, F.; Rietjens, J.H.H.; Apituley, A.; Volten, H.; Mijling, B.; Di Noia, A.; Heikamp, S.; Heinsbroek, R.C.; Hasekamp, O.P.; Smit, J.M.; Vonk, J.; Stam, D.M.; Van Harten, G.; De Boer, J.; Keller, C.U.","","2014","To assess the impact of atmospheric aerosols on health, climate, and air traffic, aerosol properties must be measured with fine spatial and temporal sampling. This can be achieved by actively involving citizens and the technology they own to form an atmospheric measurement network. We establish this new measurement strategy by developing and deploying iSPEX, a low-cost, mass-producible optical add-on for smartphones with a corresponding app. The aerosol optical thickness (AOT) maps derived from iSPEX spectropolarimetric measurements of the daytime cloud-free sky by thousands of citizen scientists throughout the Netherlands are in good agreement with the spatial AOT structure derived from satellite imagery and temporal AOT variations derived from ground-based precision photometry. These maps show structures at scales of kilometers that are typical for urban air pollution, indicating the potential of iSPEX to provide information about aerosol properties at locations and at times that are not covered by current monitoring efforts.","aerosols; polarimetry; citizen science; smartphones","en","journal article","American Geophysical Union","","","","","","","","Aerospace Engineering","Space Engineering","","","",""
"uuid:6cb734fc-5d5e-45f0-b4b7-42bdde07eaae","http://resolver.tudelft.nl/uuid:6cb734fc-5d5e-45f0-b4b7-42bdde07eaae","Assessment of Body-Powered Upper Limb Prostheses by Able-Bodied Subjects, using the Box and Blocks Test and the Nine Hole Peg Test","Haverkate, L.; Smit, G.; Plettenburg, D.H.","","2014","Study Design: Experimental trial. Background: The functional performance of currently available body-powered prostheses is unknown. Objective: The goal of this study was to objectively assess and compare the functional performance of three commonly used body-powered upper limb terminal devices. Methods: Twenty-one able-bodied subjects (n=21, age= 22±2) tested three different terminal devices: TRS VC Hook Grip 2S, Otto Bock VO Hand, and Hosmer model 5XA hook, using a prosthesis simulator. All subjects used each terminal device 9 times in two functional tests; the Nine Hole Peg Test (NHPT) and the Box and Blocks Test (BBT). Results: Significant differences were found between the different terminal devices and their scores on the NHPT and the BBT. The Hosmer hook scored best in both tests. The TRS Grip hook 2S scored second best. The Otto Bock hand showed the lowest scores. Conclusions: This study is a first step in the comparison of functional performances of body-powered prostheses. The data can be used as a reference value, to assess the performance of a terminal device or an amputee.","upper limb; prosthetics; functional testing; Box and Blocks Test; BBT; Nine Hole Peg Test; NHPT; body-powered; terminal device; assessment; prosthesis simulator; hand prosthesis; hand prostheses; voluntary closing; voluntary opening; prosthesis evaluation; handprothese; handprothesen; armprothese; armprothesen; kunstledematen","en","journal article","SAGE Journals","","","","","","","","Mechanical, Maritime and Materials Engineering","BioMedical Engineering","","","",""
"uuid:830e38fa-34e4-4b83-9a67-0a39343a7df1","http://resolver.tudelft.nl/uuid:830e38fa-34e4-4b83-9a67-0a39343a7df1","The Lightweight Delft Cylinder Hand, the First Multi-Articulating Hand That Meets the Basic User Requirements","Smit, G.; Plettenburg, D.H.; Van der Helm, F.C.T.","","2014","Rejection rates of upper limb prostheses are high (23-45%). Amputees indicate that the highest design priority should be reduction of the mass of the prosthetic device. Despite all efforts, the mass of the new prosthetic hands is 35-73% higher than that of older hands. Furthermore current hands are thicker than a human hand, they operate slower and do not provide proprioceptive force and position feedback. This study presents the Delft Cylinder Hand, a body powered prosthetic hand which mass is 55-68% lower than that of the lightest current prosthetic hands, operates faster, has an anthropomorphic shape, and provides proprioceptive force and position feedback. The hand has articulating fingers, actuated by miniature hydraulic cylinders. The articulating fingers adapt itself to the shape of the grasped object. Its functional scores are similar to that of current prosthetic devices. The hand has a higher mechanical performance than current body powered hands. It requires 49-162% less energy from the user and it can deliver a higher maximum pinch force (30-60 N).","handprothese; handprothesen; prosthetic hand; prosthetics; body powered; upper limb; artifical limb; kunstledematen; Delft Cylinder Hand; armprothese; armprothesen; prosthesis; prostheses; voluntary closing","en","journal article","IEEE","","","","","","","","Mechanical, Maritime and Materials Engineering","BME","","","",""
"uuid:e31e2650-c6f1-4baf-a5f0-43eafd054916","http://resolver.tudelft.nl/uuid:e31e2650-c6f1-4baf-a5f0-43eafd054916","Alternative Source Terms for SWAN in the Coastal Region","Salmon, J.E.; Holthuijsen, L.H.; Smit, P.B.; Van Vledder, G.P.; Zijlema, M.","","2014","This paper presents the application of new source terms in SWAN for the dominant water wave physics in the coastal zone: depth-induced breaking and triad wave-wave interactions. We present results demonstrating increased modelling skill in the prediction of bulk wave parameters e.g. significant wave height and of the spectral shape compared to currently used defaults, particularly in cases with horizontal bathymetries. These preliminary results suggest a greater range of applicability of these source terms for operational applications.","shallow wave breaking; triad wave-wave interactions; spectral wave modelling; SWAN; wave interactions; ICCE 2014","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:7865ae48-a1c4-47ce-aedc-f62e6d04645a","http://resolver.tudelft.nl/uuid:7865ae48-a1c4-47ce-aedc-f62e6d04645a","Deterministic and Stochastic Modelling of Ocean Surface Waves","Smit, P.B.","Stelling, G.S. (promotor)","2014","Predicting the mean wave statistics in the nearshore, for instance the significant wave height, has predominantly been the domain of operational stochastic wave models based on the radiative transport (or energy balance) equation. Although reasonably successful in the nearshore, these models were originally developed for oceanic scales, and necessarily neglect or parametrise processes that are only significant in shallow water, such as the linear processes of interference and diffraction, or the nonlinear triad wave-wave interactions and dissipation due to wave breaking. In this dissertation we investigate the possibility of predicting the wave statistics on small scales in strongly non-linear conditions, such as found in the surfzone, using the recently developed Surface WAves till SHore (SWASH) model, whereas on larger scales we pursue a generalisation of existing stochastic models by incorporating coherent effects, hereby extending these models to include interference and diffractive effects.","Waves; Ocean; Stochastic; Deterministic; Swash","en","doctoral thesis","VSSD","","","","","","","2014-06-06","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:0b983aa8-ed8e-404a-96d9-4b2f324924d2","http://resolver.tudelft.nl/uuid:0b983aa8-ed8e-404a-96d9-4b2f324924d2","A mechanism to compensate undesired stiffness in joints of prosthetic hands","Smit, G.; Plettenbrug, D.H.; Van der Helm, F.C.T.","","2014","Background: Cosmetic gloves that cover a prosthetic hand have a parasitic positive stiffness that counteracts the flexion of a finger joint. Objectives: Reducing the required input torque to move a finger of a prosthetic hand by compensating the parasitic stiffness of the cosmetic glove. Study design: Experimental, test bench. Methods: The parasitic positive stiffness and the required input torques of a polyvinyl chloride glove and a silicone glove were measured when flexing a metacarpophalangeal finger joint for 90°. To compensate this positive stiffness, an adjustable compensation mechanism with a negative stiffness was designed and built. A MATLAB model was created to predict the optimal settings of the mechanism, based on the measured stiffness, in order to minimize the required input torque of the total system. The mechanism was tested in its optimal setting with an applied glove. Results: The mechanism reduced the required input torque by 58% for the polyvinyl chloride glove and by 52% for the silicone glove. The total energy dissipation of the joint did not change significantly. Conclusions: This study shows that the undesired positive stiffness in the joint can be compensated with a relatively simple negative stiffness mechanism, which fits inside a finger of a standard cosmetic glove. Clinical relevance This study presents a mechanism that compensates the undesired stiffness of cosmetic gloves on prosthetic hands. As a result, it requires less input force, torque and energy to move the fingers. Application of this mechanism in body-powered hands will reduce the control effort of the user.","upper limb; prosthetics; cosmetic glove; compensation mechanism; prosthetic design; hand prosthesis; hand prostheses; hysteresis; pinch force; handprothese; handprothesen; armprothese; armprothesen; kunstledematen","en","journal article","SAGE Journals","","","","","","","","Mechanical, Maritime and Materials Engineering","BioMedical Engineering","","","",""
"uuid:77ef5ec4-0772-4fe2-85f3-5dcb96beff5e","http://resolver.tudelft.nl/uuid:77ef5ec4-0772-4fe2-85f3-5dcb96beff5e","Nadere verkenning Groene Dollard Dijk: Een civieltechnische, juridische en maatschappelijke verkenning naar de haalbaarheid van een brede groene dijk en mogelijke kleiwinning uit de kwelders","Van Loosn-Steensma, J.M.; Schelfhout, H.A.; Broekmeyer, M.E.A.; Paulissen, M.P.C.P.; Oostenbrink, W.T.; Smit, C.; Cornelius, E.J.; Jolink, E.","TU Delft","2014","In dit rapport worden de mogelijkheden voor een brede groene dijk langs de Dollard nader verkend. Zon brede groene dijk heeft een met klei en gras bekleed flauw buitentalud dat geleidelijk over gaat in de voorliggende kwelders. Door het flauwe talud en de dikke klei laag is geen asfalt of steenbekleding nodig. Een Groene Dollard Dijk is veilig en past goed in het Waddenlandschap. Wel neemt een brede groene dijk meer ruimte in beslag en is er meer klei nodig dan voor een traditionele dijk. Dit rapport schetst de civieltechnische aspecten, de kosten en de baten van de Groene Dollard Dijk, en de juridische implicaties van de implementatie van een brede groene dijk. Ook worden de eerste bevindingen gegeven van het proces waarin met eigenaren en beheerders van de kwelders wordt gezocht naar geschikte locaties voor kleiwinning. Tenslotte worden ervaringen met het (cyclisch) winnen van klei samengevat.","dijk; veiligheid; landschap; kwelders; grasbekleding","nl","report","Alterra","","","","","","","","","","","","",""
"uuid:e488e0ed-979b-4431-b6fa-393112ffe57c","http://resolver.tudelft.nl/uuid:e488e0ed-979b-4431-b6fa-393112ffe57c","Supercritical Water Gasification of Biomass: A Literature and Technology Overview","Yakaboylu, O.; Harinck, J.; Smit, K.G.; De Jong, W.","","2014","The supercritical water gasification process is an alternative to both conventional gasification as well as anaerobic digestion as it does not require drying and the process takes place at much shorter residence times; a few minutes at most. The drastic changes in the thermo-physical properties of water from the liquid state to the supercritical state make it a promising technology for the efficient conversion of wet biomass into a product gas that after upgrading can be used as substitute natural gas. The earliest research goes back as far as the 1970s and since then, supercritical water has been the subject of many research works in the field of thermochemical conversion of wet biomass. This article reviews the state of the art of the supercritical water gasification technology starting from the thermophysical properties of water and the chemistry of reactions to the process challenges of such a biomass based supercritical water gasification process plant.","biomass; supercritical water; gasification; hydrothermal; OA-Fund TU Delft","en","journal article","MDPI","","","","","","","","Mechanical, Maritime and Materials Engineering","Process and Energy","","","",""
"uuid:a8c2e360-f686-4ec5-af6d-75bf33f6245e","http://resolver.tudelft.nl/uuid:a8c2e360-f686-4ec5-af6d-75bf33f6245e","Design and evaluation of two different finger concepts for body-powered prosthetic hand","Smit, G.; Plettenburg, D.H.; Van der Helm, F.C.","","2014","The goal of this study was to find an efficient method of energy transmission for application in an anthropomorphic underactuated body-powered (BP) prosthetic hand. A pulley-cable finger and a hydraulic cylinder finger were designed and tested to compare the pulley-cable transmission principle with the hydraulic cylinder transmission principle. Both fingers had identical dimensions and a low mass. The only thing that differed between the fingers was the transmission principle. The input energy was measured for a number of tasks. The pulley-cable finger required more input energy than the hydraulic cylinder finger to perform the tasks. This was especially the case in tasks that required high pinch forces. The hydraulic cylinder transmission is therefore the more efficient transmission for application in BP prosthetic fingers.","articulating finger; body-powered; efficiency; hydraulic cylinder finger; hysteresis; prosthetic design; prosthetics; pulley-cable finger; qualitative testing; upper limb","en","journal article","Rehabilitation Research and Development Service","","","","","","","","Mechanical, Maritime and Materials Engineering","Biomechanical Engineering","","","",""
"uuid:59991074-c939-48e7-aa10-5f64e4551d86","http://resolver.tudelft.nl/uuid:59991074-c939-48e7-aa10-5f64e4551d86","Strengthening future electricity grid of the Netherlands by integration of HTS transmission cables","Zuijderduin, R.; Chevtchenko, O.; Smit, J.J.; Aanhaanen, G.; Ross, R.","","2014","The electricity grid of the Netherlands is changing. There is a call of society to use more underground cables, less overhead lines (OHL) and to reduce magnetic emissions. At the same time, parts of the future transmission grid need strengthening depending on the electricity demand in the coming decades [1]. Novel high temperature superconductor (HTS) AC transmission cables can play a role in strengthening the grid. The advantages as compared to alternatives, are: economic, underground, higher power capacity, lower losses, reduced magnetic field emissions in (existing) OHL, compact: less occupation of land and less permits needed, a possibility to keep 380 kV voltage level in the grid for as long as needed. The main obstacles are: the relatively high price of HTS tapes and insufficient maturity of the HTS cable technology. In the paper we focus on a 34 km long connection in the transmission grid (to be strengthened in three of the four of TenneT scenarios [1]), present the network study results, derive the requirements for corresponding HTS transmission cable system and compare HTS system to the alternatives (OHLs and XLPE cables).","superconductivity","en","conference paper","IOP","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:2440f6ee-7cf6-42af-b96b-ed53337377ef","http://resolver.tudelft.nl/uuid:2440f6ee-7cf6-42af-b96b-ed53337377ef","Speeddebat Werkt de wijkaanpak?","Smit, V.","","2013","","leefbaarheid; wijken","nl","conference paper","","","","","","","","","","","","","",""
"uuid:4a8e927e-809c-4de9-9cb9-b9edaf2e22db","http://resolver.tudelft.nl/uuid:4a8e927e-809c-4de9-9cb9-b9edaf2e22db","Swan and its recent developments (poster)","Zijlema, M.; Van Vledder, G.P.; Holthuijsen, L.H.; Salmon, J.E.; Smit, P.B.","","2013","The SWAN model is a third-generation spectral wave prediction model developed by Delft University of Technology. Since its initial release in 1998 this model has become a widely used and reliable tool for offshore and near shore wave predictions. Its main field of application is the coastal zone where, by virtue of its implicit numerical scheme, it can be considered as a very efficient tool for high resolution coastal applications. Besides this field of application it is also appropriate for open ocean conditions.","","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:b7daf073-682d-4625-94e0-456ae2151917","http://resolver.tudelft.nl/uuid:b7daf073-682d-4625-94e0-456ae2151917","The Evolution of Inhomogeneous Wave Statistics through a Variable Medium","Smit, P.B.; Janssen, T.T.","","2013","The interaction of ocean waves with variable currents and topography in coastal areas can result in inhomogeneous statistics because of coherent interferences, which affect wave-driven circulation and transport processes. Stochastic wave models, invariably based on some form of the radiative transfer equation (or action balance), do not account for these effects. The present work develops and discusses a generalization of the radiative transfer equation that includes the effects of coherent interferences on wave statistics. Using multiple scales, the study approximates the transport equation for the (complete) second-order wave correlation matrix. The resulting model transports the coupled-mode spectrum (a form of the Wigner distribution) and accounts for the generation and propagation of coherent interferences in a variable medium. The authors validate the model through comparison with analytic solutions and laboratory observations, discuss the differences with the radiative transfer equation and the limitations of this approximation, and illustrate its ability to resolve coherent interference structures in wave fields such as those typically found in refractive focal zones and around obstacles.","gravity waves; oceanic waves; stochastic models","en","journal article","American Meteorological Society","","","","","","","2014-03-01","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:6351529f-fd6e-4860-9d5c-29c5ef21c979","http://resolver.tudelft.nl/uuid:6351529f-fd6e-4860-9d5c-29c5ef21c979","Comparison of mechanical properties of silicone and PVC (polyvinylchloride) cosmetic gloves for articulating hand prostheses","Smit, G.; Plettenburg, D.H.","","2013","Current articulating electric and body-powered hands have a lower pinch force (15–34 N) than electric hands with stiff fingers (55–100 N). The cosmetic glove, which covers a hand prosthesis, negatively affects the mechanical efficiency of a prosthesis. The goal of this study is to mechanically compare polyvinylchloride (PVC) and silicone cosmetic gloves and quantify the stiffness of the finger joints, the required actuation energy, and the energy dissipation during joint articulation. Six cosmetic gloves, identical in size but made from different materials, were mechanically tested: three PVC and three silicone. The silicone gloves required less work and dissipated less energy during flexing. They also had a lower joint stiffness and required a lower maximum joint torque. Based on energy requirements, joint stiffness, and required joint torque, the tested silicone glove is most suitable for application on an articulating hand prosthesis.","body powered; efficiency; hysteresis; prosthetic design; prosthetic evaluation; prosthetic hand; cosmetic glove; silocone glove; pvc glove; handprothese; handprothesen; armprothese; armprothesen; kunstledematen; upper limb","en","journal article","U.S. Department of Veterans Affairs","","","","","","","","Mechanical, Maritime and Materials Engineering","BioMechanical Engineering","","","",""
"uuid:0231b507-ebe4-466b-b9ac-21e6ae2c780d","http://resolver.tudelft.nl/uuid:0231b507-ebe4-466b-b9ac-21e6ae2c780d","Natural grasping, design and evaluation of a voluntary closing adaptive hand prosthesis","Smit, G.","Van der Helm, F.C.T. (promotor); Plettenburg, D.H. (promotor)","2013","Replacement of a missing hand by an artificial alternative remains one of the biggest challenges in rehabilitation. Although many different terminal devices are available, around 27% of the amputees does not actively use their device and 20% totally refrains from wearing it. There are various reasons for prosthesis abandonment, e.g. wearing discomfort (too heavy, too hot), too little added functionality, difficult or tiring to use, lack of sensory feedback. User studies identified multiple aspects of the prostheses that need improvement, in order to meet the user demands. Mass reduction was identified as the most important design priority. In general the user demands can be summarised by the three C’s: Cosmesis, Comfort, and Control. The prosthesis should be beautiful to look at, comfortable to wear, and easy to operate. The goal of this thesis was to design and test a new lightweight and efficient body-powered hand prosthesis with articulating fingers. A low mass will increase wearing comfort. Mechanical efficiency will decrease the required actuation force, which will lead to an increased control comfort. It will also enable the hand to produce a higher pinch force, which will increase the functionality of the hand. The articulating fingers of the hand will enable both power and pinch grip. This enables the grasping and holding of a broad range of different objects and enhances natural cosmesis. The first step of the study was to determine the state-of-the-art in body-powered prostheses. Chapter 2 describes the testing of voluntary closing devices and Chapter 3 the testing of voluntary opening devices. The mechanical performance of the hooks was better than that of the hands. The hands required a high actuation force and energy (1058-2292 Nmm). They dissipated a large part of the actuation energy and produced only a low pinch force (~15 N). The mass of the hands was high (~423 gram). Comparison with data of a study from 1987 showed no improvement in the mechanical performance of the terminal devices over the last decades. In order to meet the user demands, a new hand design should have a lower mass, require less actuation energy, dissipate less energy and should be able to produce a higher pinch force. Chapter 4 describes the design and testing of two underactuated finger prototypes. One finger had a pulley cable transmission, the other a hydraulic cylinder transmission. The fingers were optimized for application in a finger of a cosmetic glove of a prosthetic hand. The fingers had identical dimensions and they had a very low mass. Quantitative mechanical tests were performed to select the most efficient way of transmission. The pulley finger required 35-74% more energy for various tasks than the hydraulic finger. Based on the results the hydraulic finger was selected as the most suitable for application in a prosthetic hand, as it had a higher energy efficiency than the pulley finger. Furthermore the hydraulic transmission offers an additional improvement of efficiency of 10-40% of the entire system, when hydraulics is used to replace the Bowden-cable in the shoulder harness. Therefore the hydraulic transmission was chosen to be used in the new hand prototype. Chapter 5 describes the mechanical comparison of silicone and PVC cosmetic gloves. Both types of gloves can be used for a prosthesis. The tests were performed to select the most energy efficient cosmetic glove. The tested silicone gloves had a 2.5-4.5 lower stiffness than the PVC glove, required 1.8 to 3.8 times less actuation energy and dissipated 1.7 to 3.4 times less energy. Therefore for the new hand prototype a silicone glove was used. Chapter 6 describes the design and testing of a glove compensation mechanism. This mechanism, which fit inside a finger, had a negative stiffness which compensates the undesired positive stiffness of a cosmetic glove. The negative stiffness of the mechanism reduced the required input torque range by 58% for the PVC glove and by 52% for the silicone glove. A negative stiffness mechanism was applied to the new hand prototype, in order to reduce the actuation effort for the user. The final step of the study was the design, and testing of a new hand prototype, described in Chapter 7. The new hand prototype, the Delft Cylinder Hand, has underactuated articulating fingers which adapt to the grasped object. It has voluntary closing body-powered control and it has a hydraulic cylinder transmission. The hand was subjected to various mechanical and functional tests. Chapter 8 describes the comparison of the performance of the hand to current available hands. Through the application of a hydraulic transmission, the hand requires 49-162% less energy from the user when compared to commercially available body-powered hands and it has a higher maximum pinch force (30-60 N). In functional tests the hand scored similar to current myoelectric hands. Yet its mass (152 gram without glove; 217 gram with glove) is 68% lower than the lightest available articulating myoelectric hand and 55% less than the lightest body-powered hand of similar size. Functional tests showed that The ‘Delft Cylinder hand’ provides the amputee with a level of function that is at least comparably to contemporary hands, at a cost (mass and actuation effort) which is much lower than that of all currently available hands. The Delft Cylinder Hand has articulating fingers and is anthropomorphic, slender, fast, efficient and silent. The hand mass is much lower than the lightest commercially available hand. The hand therefore meets one of the most important user demands in upper limb prosthetics, which is a low hand mass. The hand can pinch harder (>30 N) at a lower user effort. Samenvatting Natuurlijk Grijpen: Ontwerp en evaluatie van een actief sluitende adaptieve hand prothese Het vervangen van een ontbrekende menselijke hand, door een kunsthand is een van de grootste uitdagingen op het gebied van de revalidatie. Hoewel er veel verschillende handprothesen beschikbaar zijn, gebruikt 27% van de handprothesedragers de prothese niet actief en draagt 20% helemaal geen prothese. Er zijn verschillende redenen waarom mensen stoppen met het dragen van de prothese, bijv. draagcomfort (te zwaar, te warm), te weinig functioneel voordeel, moeilijk of vermoeiend in het gebruik, gebrek aan sensorische feedback. Gebruikersstudies laten zien dat verschillende aspecten van de prothesen verbeterd dienen te worden, om te voldoen aan de eisen van de gebruiker. Vermindering van de massa van de prothese heeft hierbij de hoogste prioriteit. De gebruikerseisen kunnen kortweg samengevat worden door de drie C’s: Cosmetiek, Comfort en Controle. De prothese moet mooi zijn om te zien, comfortabel om te dragen en moet makkelijk te bedienen zijn. Het doel van deze studie was het ontwerpen en het testen van een lichtgewicht en mechanisch efficiënte lichaamsbekrachtigde handprothese met articulerende ofwel scharnierende vingers. Een lage prothesemassa zal het draagcomfort verbeteren. Mechanische efficiëntie zal de bedieningskracht verlagen en daarmee het bedieningscomfort verhogen. Ook zal de hand hierdoor harder kunnen knijpen, wat zal resulteren in een verbeterde functionaliteit van de hand. De articulerende vingers maken het mogelijk om zowel de pincetgreep als de cilindergreep te vormen. Hierdoor kan een breed scala aan verschillende objecten worden vastgehouden. Bovendien verbetert dit de natuurlijke cosmetiek. De eerste stap in de studie was om de state-of-the-art van de huidige lichaamsbekrachtigde prothesen te bepalen. Hoofdstuk 2 beschrijft het testen van actief sluitende prothesen en hoofdstuk 3 beschrijft het testen van actief openende prothesen. De mechanische efficiëntie van de geteste haken was beter dan die van de handen. Voor het bedienen van de handen was een hoge bedieningsinspanning en bedieningsenergie (1058-2292 Nmm) nodig. Ook dissipeerden de handen een groot gedeelte van de bedieningsenergie en leverden ze slechts een lage knijpkracht (~15 N). De massa van de handen was hoog (~423 gram). Een vergelijking met de resultaten van een studie uit 1987 liet zien dat de prothesen de afgelopen decennia niet verbeterd waren. Om te voldoen aan de gebruikerseisen moet een nieuw handontwerp een lagere massa hebben, minder bedieningsenergie vragen, minder bedieningsenergie dissiperen en de hand dient een hogere knijpkracht te leveren. Hoofdstuk 4 beschrijft het ontwerp en het testen van twee ondergeactueerde vingerprototypen. Het ene vingerprototype was voorzien van een kabel-katrol transmissie, het andere van een hydraulisch transmissie. Beide vingers waren geoptimaliseerd voor toepassing in een cosmetische handschoen van een handprothese. De vingers hadden identieke afmetingen en hadden een erg lage massa. Er zijn kwantitatieve testen uitgevoerd om te bepalen welke transmissie het efficiëntst was. De vinger met de kabel-katrol transmissie had 35-74% meer energie nodig voor verschillende taken dan de hydraulische vinger. Vanwege de hogere mechanische efficiëntie van de hydraulische vinger, is deze vinger geselecteerd als meest geschikte vinger voor toepassing in een handprothese. Bovendien biedt een hydraulische transmissie een extra efficiëntieverbetering van 10-40%, wanneer de hydraulische transmissie gebruikt wordt om de Bowdenkabel te vervangen. Daarom is besloten om in het nieuwe handprototype de hydraulische transmissie toe te passen. Hoofdstuk 5 beschrijft vergelijking van mechanische eigenschappen van cosmetische handschoenen van siliconen en PVC. Beiden typen handschoen kunnen gebruikt worden op een handprothese. De testen zijn uitgevoerd om de handschoen te selecteren met de hoogste energie-efficiëntie. De stijfheid van de gemeten siliconen handschoenen was 2.5-4.5 keer lager dan die van de PVC handschoenen. De siliconen handschoen hadden een 1.8 tot 3.8 keer lagere actuatie-energie nodig en dissipeerden 1.7 tot 3.4 keer minder energie. Er is daarom gekozen om voor het nieuwe hand prototype een siliconen handschoen te gebruiken. Hoofdstuk 6 beschrijft het ontwerp en het testen van een handschoencompensatiemechanisme. Dit mechanisme, dat binnenin een vinger past, heeft een negatieve stijfheid die de ongewenste positieve stijfheid van de handschoen compenseert. De negatieve stijfheid van het mechanisme verminderde het benodigde actuatiemoment met 58% voor de PVC handschoen en met 52% voor de siliconen handschoen. In het nieuwe handprototype is ook een mechanisme met een negatieve stijfheid toegepast, om de vereiste bedieningsinspanning van de gebruiker te verlagen. De laatste stap van de studie was het ontwerpen en het testen van een nieuwe handprototype, beschreven in hoofdstuk 7. Het nieuwe handprototype, de Delft Cylinder Hand, heeft ondergeactueerde articulerende vingers die zich aanpassen aan de vorm van het object. De hand wordt bediend met een lichaamsbekrachtigde actief-sluitende bediening. De transmissie van de hand is hydraulisch. De hand is onderworpen aan verschillende mechanische en functionele testen. Hoofdstuk 8 beschrijft de vergelijking van de prestaties van de hand met die van de huidige prothesehanden. Door de toepassing van een hydraulische transmissie hoeft de gebruiker 49-162% minder energie te leveren om de hand te bedienen dan voor de huidige lichaamsbekrachtigde handen nodig is. De hand kan een hogere knijpkracht leveren (30-60 N). In de functionele testen behaalde de hand vergelijkbare scores als die van myo-elektrische handen. De massa van de hand (152 gram zonder handschoen; 217 gram met handschoen) is 68% lager dan die van de lichtste articulerende myo-elektrische hand en 55% lager dan die van de lichtste lichaamsbekrachtigde hand van vergelijkbaar formaat. De functionele testen lieten zien dat de ‘Delft Cylinder Hand’ de prothesegebruiker een functionaliteit biedt die tenminste vergelijkbaar is met die van de huidige prothesehanden, tegen een belasting (handmassa en bedieningsinspanning) die veel kleiner is dan die van alle huidig beschikbare handen. De Delft Cylinder Hand heeft articulerende vingers en is antropomorfisch, rank, snel, efficiënt en stil. De handmassa is veel lager dan die van de lichtste commercieel verkrijgbare hand. De hand beantwoord daarmee aan een van de belangrijkste gebruikerseisen, namelijk die van een lage handmassa. De hand kan harder knijpen (>30 N) met een lagere bedieningsinspanning.","body powered; efficiency; hysteresis; prosthetic design; prosthetic evaluation; prosthetic hand; prosthetics; qualitative testing; upper limb; voluntary opening; handprothese; handprothesen; armprothese; armprothesen; kunstledematen; Delft Cylinder Hand; hydrauliek; hydraulics; pinch force","en","doctoral thesis","TU Delft","","","","","","","2015-02-09","Mechanical, Maritime and Materials Engineering","BioMechanical Engineering","","","",""
"uuid:e149bfb4-12e4-4d1c-91fd-222296dfe623","http://resolver.tudelft.nl/uuid:e149bfb4-12e4-4d1c-91fd-222296dfe623","Shallow Water Effects - Influence of trim and water depth on power demand for a dredger using RaNS based CFD calculations","Smit, E.","Huijsmans, R.H.M. (mentor)","2013","","hydrodynamics","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:9c1615f4-dfc2-4729-9b6b-cdded210e01d","http://resolver.tudelft.nl/uuid:9c1615f4-dfc2-4729-9b6b-cdded210e01d","Low Friction Cryostat for HTS Power Cable of Dutch Project","Chevtchenko, O.; Zuijderduin, R.; Smit, J.; Willen, D.; Lentge, H.; Thidemann, C.; Traeholt, C.","","2012","Particulars of 6 km long HTS AC power cable for Amsterdam project are: a cable has to fit in an annulus of 160 mm, with only two cooling stations at the cable ends [1]. Application of existing solutions for HTS cables would result in excessively high coolant pressure drop in the cable, possibly affecting public acceptance of the project. In order to solve this problem, a model cryostat was developed consisting of alternating rigid and flexible sections and hydraulic tests were conducted using sub-cooled liquid nitrogen. In the 47 m-long cryostat, containing a full-size HTS cable model, measured pressure drop amounts 11 mbar at the mass flow rate of 0.3 kg/s and temperature 65 K. For a 6 km-long HTS cable this gives a pressure drop below 2 bar, which is acceptable. In order to achieve this result, the cryostat was manufactured from alternating straight rigid sections and corrugated flexible sections. A flexible dummy HTS cable was inserted into this cryostat and sub-cooled liquid nitrogen was circulated in the annulus between the dummy cable surface and the inner cryostat surface. In the paper details are presented of the cryostat, of the measurement setup, of the experiment and of the results.","long HTS AC power cable; Dutch project; model cryostat; alternating rigid and flexible sections; hydraulic measurements; low friction; Reynolds number; friction factor","en","journal article","Elsevier","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:8c42112a-822b-45c8-b7e0-0766580de680","http://resolver.tudelft.nl/uuid:8c42112a-822b-45c8-b7e0-0766580de680","AC HTS Transmission Cable for Integration into the Future EHV Grid of the Netherlands","Zuijderduin, R.; Chevtchenko, O.; Smit, J.J.; Aanhaanen, G.; Melnik, I.; Geschiere, A.","","2012","Due to increasing power demand, the electricity grid of the Netherlands is changing. The future grid must be capable to transmit all the connected power. Power generation will be more decentralized like for instance wind parks connected to the grid. Furthermore, future large scale production units are expected to be installed near coastal regions. This creates some potential grid issues, such as: large power amounts to be transmitted to consumers from west to east and grid stability. High temperature superconductors (HTS) can help solving these grid problems. Advantages to integrate HTS components at Extra High Voltage (EHV) and High Voltage (HV) levels are numerous: more power with less losses and less emissions, intrinsic fault current limiting capability, better control of power flow, reduced footprint, etc. Today's main obstacle is the relatively high price of HTS. Nevertheless, as the price goes down, initial market penetration for several HTS components is expected by year 2015 (e.g.: cables, fault current limiters). In this paper we present a design of intrinsically compensated EHV HTS cable for future grid integration. Discussed are the parameters of such cable providing an optimal power transmission in the future network.","national transmission grid; potential bottlenecks; high temperature superconducting cables; compensation of reactive power; intrinsically compensated cable","en","journal article","Elsevier","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:f06a121d-86fb-4384-b3a8-7fb203d04daf","http://resolver.tudelft.nl/uuid:f06a121d-86fb-4384-b3a8-7fb203d04daf","Low AC Loss in a 3 kA HTS Cable of the Dutch Project","Chevtchenko, O.; Zuijderduin, R.; Smit, J.; Willen, D.; Lentge, H.; Thidemann, C.; Traeholt, C.; Melnik, I.; Geschiere, A.","","2012","are: a cable has to fit in an annulus of 160 mm, with two cooling stations at the cable ends only. Existing solutions for HTS cables would lead to excessively high coolant pressure drop in the cable, potentially affecting public acceptance of the project. A way out would be to substantially reduce AC losses from 1 down to about 0.1 W/m per phase at rated current of 3 kArms, frequency of 50 Hz and temperature of 77 K. In this paper we discuss a strategy towards this ambitious goal, a concept design of the single phase cable 3 kA conductor made of YBCO tapes and present corresponding experimental and simulation data supporting the developed approach leading directly to this goal. HTS cable model was made that show a drastically reduced AC loss. The low loss was achieved by using appropriate pitch angles for two-layer cable conductor of relatively large diameter, by minimizing the gaps between the HTS tapes, and by using narrow HTS tapes that conform well to the roundness of the underlying former. AC loss of 0.12 W/m at 3 kArms was measured at a frequency of 60 Hz and at a temperature of 77 K.","long HTS AC power cable; Dutch project; 3 kA class YBCO cable conductor; single phase model; very low AC losses at 60 Hz and 77 K; concept; experiment; simulation","en","journal article","Elsevier","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:5acc250d-d8cd-4724-b53d-472faa4fb8e8","http://resolver.tudelft.nl/uuid:5acc250d-d8cd-4724-b53d-472faa4fb8e8","Electrical Model of Balanced AC HTS Power Cable","Zuijderduin, R.; Chevtchenko, O.; Smit, J.J.; Willen, D.; Melnik, I.; Geschiere, A.","","2012","The future electricity grid will be more sustainable and it will have more power transmission and distribution capability with more electrical power added from decentralized sources on distribution level and from wind parks and other large sources on transmission level. More interconnections and more underground transmission and distribution will be put up. Use of high temperature superconducting (HTS) power cables provides solutions to many of the future grid problems caused by these trends. In this paper we present an electrical model of a balanced 6 km-long three phase triaxial HTS power cable for the Dutch project being developed by a consortium of Alliander, Ultera and TUD. The cable currents in all three phases are balanced by selecting proper twist pitches and insulation thickness. The paper focuses on determining inductances, capacitances and AC losses of the balanced cable. Using the developed model, we also determine the voltage drop as function of the cable length, the neutral current and the effect of the imbalanced capacitances on the current distribution of the Dutch distribution cable. The model is validated and it can be used for accurate simulation of the electrical behaviour of triaxial HTS cables in electrical grids.","high temperature superconducting power cable; Dutch HTS cable project; cable electrical parameters; balancing of inductances and capacitances; zero neutral current; modelling","en","journal article","Elsevier","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:b43601b8-62af-4be5-b7e6-c9e455519c04","http://resolver.tudelft.nl/uuid:b43601b8-62af-4be5-b7e6-c9e455519c04","Integration of HTS Cables in the Future Grid of the Netherlands","Zuijderduin, R.; Chevchenko, O.; Smit, J.J.; Aanhaanen, G.; Melnik, I.; Geschiere, A.","","2012","ue to increasing power demand, the electricity grid of the Netherlands is changing. The future transmission grid will obtain electrical power generated by decentralized renewable sources, together with large scale generation units located at the coastal region. In this way electrical power has to be distributed and transmitted over longer distances from generation to end user. Potential grid issues like: amount of distributed power, grid stability and electrical loss dissipation merit particular attention. High temperature superconductors (HTS) can play an important role in solving these grid problems. Advantages to integrate HTS components at transmission voltages are numerous: more transmittable power together with less emissions, intrinsic fault current limiting capability, lower ac loss, better control of power flow, reduced footprint, less magnetic field emissions, etc. The main obstacle at present is the relatively high price of HTS conductor. However as the price goes down, initial market penetration of several HTS components (e.g.: cables, fault current limiters) is expected by year 2015. In the full paper we present selected ways to integrate EHV AC HTS cables depending on a particular future grid scenario in the Netherlands.","national transmission grid; potential bottlenecks; high temperature superconducting cables","en","journal article","Elsevier","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:cc1ccf98-81ce-4c51-a318-b1ba37e592d2","http://resolver.tudelft.nl/uuid:cc1ccf98-81ce-4c51-a318-b1ba37e592d2","Vakmanschap van de Projectontwikkelaar?","Smit, H.H.","","2012","Projectontwikkelaars worden in de huidige markt stevig op de proef gesteld. Hans-Hugo Smit geeft zijn visie op het verleggen van de koers van aanbodgericht naar vraaggericht ontwikkelen en de rol van de ontwikkelaar daarbij.","projectontwikkelaar","nl","conference paper","","","","","","","","","","","","","",""
"uuid:8585293d-e751-4605-b2d9-3f77be64fbe4","http://resolver.tudelft.nl/uuid:8585293d-e751-4605-b2d9-3f77be64fbe4","Vakmanschap van de Projectontwikkelaar?","Smit, H.","","2012","","projectontwikkeling","nl","conference paper","","","","","","","","","","","","","",""
"uuid:0da65300-48cb-4a84-906d-61b6a7bf4b34","http://resolver.tudelft.nl/uuid:0da65300-48cb-4a84-906d-61b6a7bf4b34","Sessie 1 Wonen en de wijkaanpak: De Haagse Schilderswijk - De Schilderswijk","Smit, V.","","2012","","achterstand; huurwoningen; leefomgeving","nl","conference paper","","","","","","","","","","","","","",""
"uuid:32c6452a-3548-4105-abaa-676abe1f0387","http://resolver.tudelft.nl/uuid:32c6452a-3548-4105-abaa-676abe1f0387","Non-hydrostatic modelling of infragravity waves using swash","Rijnsdorp, D.P.; Smit, P.B.; Zijlema, M.","","2012","This paper presents numerical modelling of the nearshore transformation of infragravity waves induced by bichromatic wave groups over a horizontal and a sloping bottom. The non-hydrostatic model SWASH is assessed by comparing model predictions with analytical solutions over a horizontal bottom and with detailed laboratory observations for a sloping bottom. Good agreement between model predictions and data is found throughout the domain for bound infragravity waves. Furthermore the model predicts greater outgoing free infragravity wave-heights for steeper slope regimes which is consistent with the measurements. The model however tends to overestimate the magnitude of the outgoing infragravity waves.","infragravity waves; non-hydrostatic modelling; nearshore wave transformation; SWASH","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:d274ac33-b9b4-4db8-90b5-1dd346505206","http://resolver.tudelft.nl/uuid:d274ac33-b9b4-4db8-90b5-1dd346505206","Topography-induced focusing of random waves","Smit, P.B.; Janssen, T.T.; Herbers, T.H.C.","","2012","Refraction of narrow-band surface waves in coastal areas can result in wave-focal zones where due to interference, wave statistics vary rapidly and on similar length scales as those of individual waves. However such interference patterns, or wave coherence, are not accounted for in conventional stochastic wave models that are based on the energy balance equation or radiative transfer equation. In this work we present a quasi-coherent theory, which is an extension of the radiative transfer equation and quasi-homogeneous theory. We show that this new stochastic modelling approach can resolve rapid variations in wave statistics that occur in the vicinity of a wave caustic. The results compare favourably to those obtained from ensemble averages calculated with a deterministic phase resolving model (SWASH) and, in a focal zone, constitute a significant improvement over those obtained with a conventional stochastic wave model based on an energy balance equation (SWAN).","Wave focusing; Random waves; Stochastic wave model; Diffraction; Wave interference","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:fd615056-1246-4736-bbc7-96d783563536","http://resolver.tudelft.nl/uuid:fd615056-1246-4736-bbc7-96d783563536","Topography-induced focusing of random waves","Smit, P.B.; Janssen, T.T.; Herbers, T.H.C.","","2012","Refraction of narrow-band surface waves in coastal areas can result in wave-focal zones where due to interference, wave statistics vary rapidly and on similar length scales as those of individual waves. However such interference patterns, or wave coherence, are not accounted for in conventional stochastic wave models that are based on the energy balance equation or radiative transfer equation. In this work we present a quasi-coherent theory, which is an extension of the radiative transfer equation and quasi-homogeneous theory. We show that this new stochastic modelling approach can resolve rapid variations in wave statistics that occur in the vicinity of a wave caustic. The results compare favourably to those obtained from ensemble averages calculated with a deterministic phase resolving model (SWASH) and, in a focal zone, constitute a significant improvement over those obtained with a conventional stochastic wave model based on an energy balance equation (SWAN).","wave focusing; random waves; stochastic wave model; diffraction; wave interference","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:782c9d01-e5c6-4a1e-beb6-a62edeca3d82","http://resolver.tudelft.nl/uuid:782c9d01-e5c6-4a1e-beb6-a62edeca3d82","Non-hydrostatic modelling of infragravity waves using SWASH","Rijnsdorp, D.P.; Smit, P.B.; Zijlema, M.","","2012","This paper presents numerical modelling of the nearshore transformation of infragravity waves induced by bichromatic wave groups over a horizontal and a sloping bottom. The non-hydrostatic model SWASH is assessed by comparing model predictions with analytical solutions over a horizontal bottom and with detailed laboratory observations for a sloping bottom. Good agreement between model predictions and data is found throughout the domain for bound infragravity waves. Furthermore the model predicts greater outgoing free infragravity wave-heights for steeper slope regimes which is consistent with the measurements. The model however tends to overestimate the magnitude of the outgoing infragravity waves.","infragravity waves; non-hydrostatic modelling; nearshore wave transformation; SWASH","en","conference paper","Coastal Engineering Research Council","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:248286d2-8cd6-4a54-a9f3-8d417eb9d678","http://resolver.tudelft.nl/uuid:248286d2-8cd6-4a54-a9f3-8d417eb9d678","New materials in high voltage technology","Smit, J.J.; Andritsch, T.; Chevtchenko, O.A.","","2012","Assets in high voltage technology have to meet harsh service conditions over long lifetimes of 40 years or more. Due to environmental concerns, substitution of conventional insulating materials becomes a necessity. Because robustness and sustainability are serious requirements, only few new materials are really breaking through. At present some promising material technologies emerge with great potential applicability in high voltage engineering. This paper discusses especially nanocomposites and high temperature superconductors.","high voltage technologies, nanocomposites, superconductors","en","journal article","Springer-Verlag","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:3381b881-c668-4dc4-8107-627b2e222c10","http://resolver.tudelft.nl/uuid:3381b881-c668-4dc4-8107-627b2e222c10","Efficiency of voluntary opening hand and hook prosthetic devices, 24 years of development?","Smit, G.; Bongers, R.M.; Van der Sluis, C.K.; Plettenburg, D.H.","","2012","Quantitative data on the mechanical performance of upper-limb prostheses are very important in prostheses development and selection. The primary goal of this study was to objectively evaluate the mechanical performance of adult-size voluntary opening (VO) prosthetic terminal devices and select the best tested device. A second goal was to see whether VO devices have improved in the last two decades. Nine devices (four hooks and five hands) were quantitatively tested (Hosmer model 5XA hook, Hosmer Sierra 2 Load VO hook, RSL Steeper Carbon Gripper, Otto Bock model 10A60 hook, Becker Imperial hand, Hosmer Sierra VO hand, Hosmer Soft VO hand, RSL Steeper VO hand, Otto Bock VO hand). We measured the pinch forces, activation forces, cable displacements, mass, and opening span and calculated the work and hysteresis. We compared the results with data from 1987. Hooks required lower activation forces and delivered higher pinch forces than hands. The activation forces of several devices were very high. The pinch forces of all tested hands were too low. The Hosmer model 5XA hook with three bands was the best tested hook. The Hosmer Sierra VO hand was the best tested hand. We found no improvements in VO devices compared with the data from 1987.","body powered; efficiency; hysteresis; prosthetic design; prosthetic evaluation; prosthetic hand; prosthetics; qualitative testing; upper limb; voluntary opening","en","journal article","U.S. Department of Veterans Affairs","","","","","","","","Mechanical, Maritime and Materials Engineering","BioMechanical Engineering","","","",""
"uuid:5b6db1c6-e7f1-4562-a051-2be0e1ff109a","http://resolver.tudelft.nl/uuid:5b6db1c6-e7f1-4562-a051-2be0e1ff109a","Simulating nearshore wave transformation with non-hydrostatic wave-flow modelling","Zijlema, M.; Smit, P.B.; Stelling, G.S.","","2011","","","en","conference paper","s.n.","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:aa46bedf-6ca4-4546-a268-64cc3e0497ba","http://resolver.tudelft.nl/uuid:aa46bedf-6ca4-4546-a268-64cc3e0497ba","Sessie A Open deuren, dichte deuren: Middeninkomensgroepen op de woningmarkt - Open deuren, dichte deuren","Smit, V.","","2011","","woningmarkt; koopsector; huishoudens","nl","conference paper","","","","","","","","","","","","","",""
"uuid:472f9e42-f67e-490d-bc95-a0d266cfdf0a","http://resolver.tudelft.nl/uuid:472f9e42-f67e-490d-bc95-a0d266cfdf0a","Open deuren, dichte deuren; middeninkomens op de woningmarkt","Smit, V.","","2011","Themasessie A: Open deuren, dichte deuren; middeninkomensgroepen op de woningmarkt","","nl","conference paper","","","","","","","","","","","","","",""
"uuid:3580c36a-a8b8-4c17-bd12-b5235831ffc0","http://resolver.tudelft.nl/uuid:3580c36a-a8b8-4c17-bd12-b5235831ffc0","Coherent interference and diffraction in random waves","Smit, P.B.; Janssen, T.T.","","2011","Wave fields traveling through a varying medium (e.g. topography, currents), can develop well-defined focal zones and caustics, where the wave field is highly coherent and wave statistics vary rapidly. However, the presence and evolution of such coherent structures in the wave field are not resolved in a quasi-homogeneous description of the wave field (e.g. the radiative transport equation), and a more general description of the wave statistics (and its evolution) is needed. In this work we demonstrate with numerical examples that, when using a (recently developed) transport equation for the second order inhomeogeneous wave statistics that accounts for cross-variance contributions, we can resolve coherent structures in wave fields such as those typically found in focal and diffraction zones. What this shows is, that in a statistical sense, diffraction is essentially an interference phenomenon that can be readily resolved if cross-phase information in the transport equations is retained.","","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:1ff38b79-4582-4ad5-a937-1dc8f0e2a738","http://resolver.tudelft.nl/uuid:1ff38b79-4582-4ad5-a937-1dc8f0e2a738","Using 18th century storm-surge data from the Dutch Coast to improve the confidence in flood-risk estimates","Baart, F.; Bakker, M.A.J.; Van Dongeren, A.; Den Heijer, C.; Van Heteren, S.; Smit, M.W.J.; Van Koningsveld, M.; Pool, A.","","2011","For the design of cost-effective coastal defence a precise estimate is needed of the 1/10 000 per year storm surge. A more precise estimate requires more observations. Therefore, the three greatest storm surges that hit the northern part of the Holland Coast in the 18th century are reconstructed. The reconstructions are based on paintings, drawings, written records and shell deposits that have recently appeared. The storm-surge levels of these storms have been estimated using numerical modelling of the coastal processes. Here we show how these reconstructions can be used in combination with extreme value statistics to give a more confident estimate of low probability events.","","en","journal article","European Geosciences Union","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:ca3611d9-c2f1-4230-9eeb-2c186275f97b","http://resolver.tudelft.nl/uuid:ca3611d9-c2f1-4230-9eeb-2c186275f97b","Modelling of the thermal conductivity in polymer nanocomposites and the impact of the interface between filler and matrix","Kochetov, R.; Korobko, A.V.; Andritsch, T.; Morshuis, P.H.F.; Picken, S.J.; Smit, J.J.","","2011","In this paper the thermal conductivity of epoxy-based composite materials is analysed. Two and three-phase Lewis–Nielsen models are proposed for fitting the experimental values of the thermal conductivity of epoxy-based polymer composites. Various inorganic nano- and microparticles were used, namely aluminium oxide, aluminium nitride, magnesium oxide and silicon dioxide with average particle size between 20 nm and 20?m. It is shown that the filler–matrix interface plays a dominant role in the thermal conduction process of the nanocomposites. The two-phase model was proposed as an initial step for describing systems containing 2 constituents, i.e. an epoxy matrix and an inorganic filler. The three-phase model was introduced to specifically address the properties of the interfacial zone between the host polymer and the surface modified nanoparticles.","","en","journal article","IOP Publishing","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:d8ed1029-29ed-4d66-9548-4b34c0efefa4","http://resolver.tudelft.nl/uuid:d8ed1029-29ed-4d66-9548-4b34c0efefa4","Cultural heritage in urban redevelopment projects: A framework to analyse collaborative strategies","Baarveld, M.Y.; Smit, M.","","2011","Due to technological, economic and spatial developments, various inner-city industrial areas have lost their former use and their original economic value. Many of these areas have elements of cultural-historical value. Preserving this cultural heritage means managing it for the benefit of current and future generations, and by doing so - contributing to a sustainable development. Governments, private parties, citizens and interest groups are often convinced of the desirability of preserving the cultural heritage. However, the presence of cultural heritage entails extra complexity. Hence, public and private parties are searching for new methods, processes and instruments to embed cultural heritage in urban redevelopment projects. In this paper we present a framework to study strategies used and their implications for balancing costs and benefits. To develop this framework, we analyzed five Dutch urban redevelopment projects with cultural heritage and confronted the results with literature. We then argue that value creation, through collaborative efforts in finding new uses, and value claiming, by negotiating on the costs and benefits involved, go hand in hand. From this perspective, value creation and settlements regarding costs and benefits of cultural heritage depend on how stakeholders handle this tension.","cultural heritage; urban redevelopment; collaborative strategies; balancing costs and benefits; negotiation","en","conference paper","","","","","","","","","","","","","",""
"uuid:eb35397e-68b3-49b2-b650-2db6aae40a2d","http://resolver.tudelft.nl/uuid:eb35397e-68b3-49b2-b650-2db6aae40a2d","A versatile low-temperature setup for the electrical characterization of single-molecule junctions","Martin, C.A.; Smit, R.H.M.; Van Egmond, R.; Van der Zant, H.S.J.; Van Ruitenbeek, J.M.","","2011","We present a modular high-vacuum setup for the electrical characterization of single molecules down to liquid helium temperatures. The experimental design is based on microfabricated mechanically controllable break junctions, which offer control over the distance of two electrodes via the bending of a flexible substrate. The actuator part of the setup is divided into two stages. The slow stage is based on a differential screw drive with a large bending range. An amplified piezoceramic actuator forms the fast stage of the setup, which can operate at bending speeds of up to 800 ?m/s. In our microfabricated break junctions this is translated into breaking speeds of several 10 nm/s, sufficient for the fast acquisition of large statistical datasets. The bandwidth of the measurement electronics has been optimized to enable fast dI/dV spectroscopy on molecular junctions with resistances up to 100 M?. The performance of the setup is demonstrated for a ?-conjugated oligo(phenyleneethynylene)-dithiol molecule.","cryogenic electronics; flexible electronics; microfabrication; molecular electronics; piezoceramics; substrates","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:93046bf8-9757-40be-8cfc-5eeca95d3c54","http://resolver.tudelft.nl/uuid:93046bf8-9757-40be-8cfc-5eeca95d3c54","Current feed forward control in dynamic positioning","Smit, M.R.; Tjallema, A.R.; Huijsmans, R.H.M.","","2011","","offshore","","conference paper","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:8c18e55f-842a-4a74-9b62-4b7fd23d9756","http://resolver.tudelft.nl/uuid:8c18e55f-842a-4a74-9b62-4b7fd23d9756","Efficiency of voluntary closing hand and hook prostheses","Smit, G.; Plettenburg, D.H.","","2010","The Delft Institute of Prosthetics and Orthotics has started a research program to develop an improved voluntary closing, body-powered hand prosthesis. Five commercially available voluntary closing terminal devices were mechanically tested: three hands [Hosmer APRL VC hand, Hosmer Soft VC Male hand, Otto Bock 8K24] and two hooks [Hosmer APRL VC hook, TRS Grip 2SS]. The test results serve as a design guideline for future prostheses. A test bench was used to measure activation cable forces and displacements, and the produced pinch forces. The measurements show that the hands require higher activation forces than the hooks and 1.5 to 8 times more mechanical work. The TRS hook requires the smallest activation force (33 N for a 15 N pinch force) and has the lowest energy dissipation (52 Nmm). The Hosmer Soft hand requires the largest activation force (131 N for a 15 N pinch force) and has the highest energy dissipation (1409 Nmm). The main recommendations for future prostheses are the following: (1) Required activation forces should be below the critical muscle force (~18% of maximum), to enable continuous activation without muscle fatigue. (2) Hysteresis of mechanism and glove should be lowered, to increase efficiency and controllability.","hand prosthesis; hand prostheses; voluntary closing; hysteresis; efficiency; pinch force; mechanical testing; handprothese; handprothesen; kunstledematen; armprothese; armprothesen; body powered; upper limb; amputation; prosthetics","en","journal article","SAGE Journals","","","","","","","","Mechanical, Maritime and Materials Engineering","BioMedical Engineering","","","",""
"uuid:667b8567-2267-41a6-a4e4-a425a1b8d4bf","http://resolver.tudelft.nl/uuid:667b8567-2267-41a6-a4e4-a425a1b8d4bf","Cryostat for a high-temperature superconducting power cable","Chevtchenko, O.A.; Smit, J.J.; Geschiere, A.","","2010","Cryostat for a high-temperature superconducting power cable, comprising concentric tubes, an annular region between said tubes, wherein a multilayer thermal insulation and getter material for supporting high vacuum conditions are provided in said annular region, and wherein the multilayer insulation comprises reflective layers separated by fibrous spacer material, wherein the fibrous spacer material comprises activated carbon micro-fibers and/or activated carbon nano-fibers. Beneficially the getter material is at least in part embodied in the activated carbon fibers of the fibrous spacer material.","","en","patent","European Patent Office","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:2458b3cd-547f-47b3-949f-e5b3db27caa2","http://resolver.tudelft.nl/uuid:2458b3cd-547f-47b3-949f-e5b3db27caa2","What determines nearshore sandbar response?","Smit, M.; Reniers, A.; Stive, M.J.F.","","2010","Nearshore sandbars appear with various patterns which may change over time. From observations, these changes seem to be related to changes in hydrodynamic conditions, although observed length scales could not be related directly to occurring wave conditions. The current work investigated the role of both the concurrent and previous hydrodynamics as well as the role of the pre-existing morphological variability of a nearshore bar system. A suite of modeling efforts using a depth-averaged process-based model was analysed on predicted length scales, response times and evolving levels of variability. It was found that with small or moderate hydrodynamic forcing, an existing pattern would remain. Only when the existing pattern was alongshore uniform, the bar pattern would change in response to the conditions. When the hydrodynamic conditions are extreme, an existing pattern can be erased, resulting in an alongshore uniform bathymetry – a reset-event","nearshore sandbars, morphodynamics, patterns, process-based modeling","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:8dd0f37e-bbcc-472c-8326-b829a1517e13","http://resolver.tudelft.nl/uuid:8dd0f37e-bbcc-472c-8326-b829a1517e13","Formation and evolution of nearshore sandbars","Smit, M.W.J.","Stive, M.J.F. (promotor); Reniers, A.J.H.M. (promotor)","2010","The aim of this study is to understand whether hydrodynamic processes or geometrical characteristics play a dominant role in the response of the nearshore sandbar system to hydrodynamic conditions. To that end a depth-averaged (2DH) process-based model has been used to compute the morphological evolution of nearshore sandbars. The morphological evolution was computed for an initially alongshore uniform beach profile with two bars with an alongshore length of 7 km, forced with constant hydrodynamic conditions over a period of two weeks. The computations aimed to investigate the evolution of the system. It was found that an identical initial cross-shore profile responds distinctly different to different constant hydrodynamic conditions, showing the role of the hydrodynamic conditions. The length scales of the bars (corresponding to rip channel distances) increased with increasing alongshore velocities and increasing depths of the bar crests. The length scales ranged from 300-700 m for the inner and 600-2000 m for the outer bar. The response time of the system was in the order of days and depends linearly on the local wave height, the alongshore current, the steepness of the bar and inversely on the active volume of the bar. Bars with a smaller volume were found to respond quicker. To speed up the morphological computations, the initial alongshore uniform bathymetries were perturbed with a random seed in the order of cm. Different seedings resulted in different locations of the evolving features, while maintaining the length scales corresponding to the forcing condition. The role of the antecedent morphology was further investigated with computations with an increasing level of initial morphological variability. A high level of variability is for example formed by deep rip channels. With deeply imprinted bathymetrical patterns, the resulting hydrodynamical patterns prohibited the evolution of new patterns. This prohibited the adaptation toward length scales that would match the concurrent forcing conditions if the initial bathymetry would have been alongshore uniform. Only if the level of variability is small (smaller than O 0.5 m), the patterns adjusted toward the expected length scales. This was found for both evolutions with increasing as well as decreasing energy levels. This explains why observed nearshore bar patterns rarely match the concurrent conditions. The antecedent level of variability is often high, which inhibits complete adaptation. Further, the forcing conditions rarely persist for periods of time that are long enough for a system to evolve towards the corresponding length scales even if the initial variability would have been minimal. A hindcast was performed of an observed morphological evolution at Palm Beach, New South Wales, Australia, during a ten day period including a storm event. Palm Beach is a pocket beach of about 2 km length. During the event, the wave energy increased from moderate to storm levels, subsequently decreasing again to moderate conditions. The observed morphological variability changed from a single barred beach with rip channels toward a reset morphology (no alongshore variability) during the storm with subsequently newly evolving rip channels during the quieter post-storm conditions. The initial bathymetries used for the model computations were inferred from video-observations of the dissipation patterns. The effect of wave groups, wave asymmetry, long wave induced sediment stirring, the amount of turbulence and the rate of morphological change was tested in creating and hindcasting the observed patterns. It was found that these processes affect the magnitude and pace of morphological evolution. With optimal settings, the model including all mentioned processes forecasted a morphological evolution with decreasing variability during the storm event -similar to the observations. However, the observed amount of increase in bathymetrical variability after the storm event could not be matched in magnitude by the model. In general, best matches with observations were obtained for computations with a duration of up to three days. Within this period the different process settings only clearly changed the morphological evolution when the storm event was included within this period. Excluding wave groups resulted in the evolution of slightly shorter length scales. During the storm event an offshore bar formed and subsequent evolution was small and occurred both near the shore (wave groups have a diffusive effect in shallow water) and in deeper water. Computations starting after the storm event showed very little difference in morphological evolution whether wave groups were included or not. Excluding wave asymmetry resulted in shoreward migration of the shoreline and very little morphological evolution after all initial features had been erased. Long wave induced sediment stirring has a large diffusive effect on the evolving morphological features. Excluding this stirring resulted in the evolution of extreme shore-attached features. When the turbulent diffusion in the model was decreased, similar types of features evolved, though at slightly different rates and moments. Increasing the rate of morphological change resulted in the evolution of increased, mainly shore-attached, morphological variability. It was found that obtaining the correct pace and magnitude of morphological evolution is crucial for the level of success. If an event would encompass only an increasing or decreasing level of energy, it could be modelled. However, maintaining the correct pace and magnitude of evolution throughout a storm event has not been achieved with the currently tested model formulations and settings. This indicates that the model formulations need improvement. It is suggested that improving the description of the diffusion, including improving the turbulence description, can improve the model's capabilities. This does not only require improved model formulations, but also increased knowledge of the turbulence processes in the nearshore zone. The location of evolving features was found to be highly sensitive to the location and depth of imprint of features in the initial bathymetry. As this is rarely available to the required degree of accuracy, it is not expected that the exact location of features will be predicted correctly. However, the length scales and level of variability could be hindcasted if optimal settings are found, process descriptions improved (e.g. the diffusion) and if the model is morphologically calibrated both for evolutions with increasing and decreasing wave energy. In conclusion, morphological evolution of nearshore sandbar patterns is found to be influenced by the initial morphology in two ways. First, if the initial variability is low, local hydrodynamic forcings -determined by the off-shore conditions and the local geometry- and their duration will determine the length scale. The location of initially small perturbations -order of cm- influences the location of rip channels. Second, if the initial morphology has a high level of variability, the bathymetry will remain the same due to the occurring hydrodynamic circulations which are reinforced by the incoming waves. Only an event with extreme energy may cause changes in the morphology in this case. The hydrodynamics seem to have a rather small role in changing the patterns of a bathymetry in case there is a significant level of variability: they reinforce existing patterns and are only capable of drastically changing existing patterns when the energy level is extremely high. They do affect the length scales and the response time in case of small initial variability. Using a morphological model requires accurate calibration of both the hydrodynamics as well as of the morphodynamics. Different nearshore processes have different effects with various magnitudes at different locations in the nearshore zone. Obtaining the correct balance between processes which amplify or damp existing patterns throughout an event with varying energy levels is currently a challenge. However, hindcasting either an up-state or a down-state morphological evolution is possible.","nearshore sandbars; morphological model; rip channel; pattern; morphologial process","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:fcf40965-5f68-4e2f-97a7-39be570ddd51","http://resolver.tudelft.nl/uuid:fcf40965-5f68-4e2f-97a7-39be570ddd51","Current feed forward control in dynamic positioning","Smit, M.","Grimmelius, H.T. (mentor)","2010","","","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Offshore and Dredging Engineering","","",""
"uuid:c6024309-5cce-44b4-b026-6713cff32fef","http://resolver.tudelft.nl/uuid:c6024309-5cce-44b4-b026-6713cff32fef","Current Feed Forward Control in Dynamic Positioning","Smit, M.R.","Huijsmans, R.H.M. (mentor)","2010","","hydrodynamics","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:b2d79961-9d60-485d-b043-6c658bb8e4de","http://resolver.tudelft.nl/uuid:b2d79961-9d60-485d-b043-6c658bb8e4de","Toezicht vergt afstand: Woningcorporaties hebben recht op vreemde ogen","Smit, V.; Boelhouwer, P.J.","","2009","","","nl","journal article","","","","","","","","","OTB Research Institute","Support Services","","","",""
"uuid:e66bd9ab-0088-49e9-bb16-7ae6d637a9f2","http://resolver.tudelft.nl/uuid:e66bd9ab-0088-49e9-bb16-7ae6d637a9f2","Electric charger for an accumulator or battery","Robers, E.W.J.; Molenaar, B.A.M.; Smit, W.; Bech, L.P.; Bouman, C.","","2009","The invention relates to an electric charger for an accumulator or a battery or the like, which is adapted for rapid charging during an on-period and comprises for this purpose control means for starting and ending the on-period. The charger is provided with a circuit for converting a supply voltage to a charging current for the battery, and further with a heat-absorbing member in heat-conducting coupling with at least an electrical component of the circuit to be protected against overheating. The control means are adapted such that the on-period cannot be restarted during an off-period following the on-period. The electric charger can hereby comprise a heat-absorbing member with a relatively low heat loss, this saving space and cost.","","en","patent","European Patent Office","","","","","","","","Mechanical, Maritime and Materials Engineering","YES! Delft","","","",""
"uuid:a1472a3d-e274-478b-bac4-9e710ac60f2b","http://resolver.tudelft.nl/uuid:a1472a3d-e274-478b-bac4-9e710ac60f2b","Optimization of condition-based asset management using a predictive health model","Bajracharya, G.; Koltunowicz, T.; Negenborn, R.R.; Papp, Z.; Djairam, D.; De Schutter, B.; Smit, J.J.","","2009","In this paper, a model predictive framework is used to optimize the operation and maintenance actions of power system equipment based on the predicted health sate of this equipment. In particular, this framework is used to predict the health state of transformers based on their usage. The health state of a transformer is hereby given by the hot-spot temperature of the paper insulation of the transformer and is predicted using the planned loading of the transformer. The actual loading of the transformer is subsequently optimized using these predictions. If you want to cite this report, please use the following reference instead: G. Bajracharya, T. Koltunowicz, R.R. Negenborn, Z. Papp, D. Djairam, B. De Schutter, J. J. Smit. Optimization of condition-based asset management using a predictive health model. In Proceedings of the 16th International Symposium on High Voltage Engineering (ISH 2009), Cape Town, South Africa, August 2009.","","en","report","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:50fcccc2-31e3-422f-8473-b5b07419b9ad","http://resolver.tudelft.nl/uuid:50fcccc2-31e3-422f-8473-b5b07419b9ad","Optimization of maintenance for power system equipment using a predictive health model","Bajracharya, G.; Koltunowicz, T.; Negenborn, R.R.; Papp, Z.; Djairam, D.; De Schutter, B.; Smit, J.J.","","2009","In this paper, a model-predictive control based framework is proposed for modeling and optimization of the health state of power system equipment. In the framework, a predictive health model is proposed that predicts the health state of the equipment based on its usage and maintenance actions. Based on the health state, the failure rate of the equipment can be estimated. We propose to use this predictive health model to predict the effects of different maintenance actions. The effects of maintenance actions over a future time window are evaluated by a cost function. The maintenance actions are optimized using this cost function. The proposed framework is applied in the optimization of the loading of transformers based on the thermal degradation of the paper insulation.","maintenance optimization; model-predictive optimization; power system maintenance; power transformer; predictive health management","en","conference paper","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:5104f187-d75f-420c-a398-3adaff99470d","http://resolver.tudelft.nl/uuid:5104f187-d75f-420c-a398-3adaff99470d","Introduction to Molecular Simulation and Statistical Thermodynamics","Vlugt, T.J.H.; Van der Eerden, J.P.J.M.; Dijkstra, M.; Smit, B.; Frenkel, D.","","2009","Statistical Thermodynamics and Molecular Simulation aim at describing the properties of systems that consist of many individual particles (atoms, molecules). Although the properties of the complete system follow directly from the properties and interactions of the individual particles, usually these properties cannot be calculated directly by using pen and paper only. Computer simulations are a convenient and modern tool to actually calculate these properties. These so-called molecular simulations are widely used in the field of chemistry and physics to (1) predict properties of existing or new materials, (2) predict new phenomena, which may lead to new experiments and the development of new theories (3) test approximate theories for these systems. Our book is organized into two parts. In Part I, the concepts of statistical thermodynamics are illustrated with simple computer simulations. These concepts (for example the second law of thermodynamics) can be quite abstract for beginning students. Our teaching experience is that computer simulations are an excellent tool for understanding these concepts. This part of the book is specifically aimed at the bachelor level. In Part II, the basics of molecular simulations are explained based on the concepts that were introduced in Part I. It is shown how these simulations can be used to calculate properties of systems of interacting molecules. This part of the book is specifically aimed at the master level. A beginning master student with some basic knowledge of classical thermodynamics will be able to start with Part II of the book.","molecular simulation; statistical mechanics","en","book","","","","","","","","","Mechanical, Maritime and Materials Engineering","Process and Energy","","","",""
"uuid:1532a009-8eac-4e52-883f-45ef411fa3f5","http://resolver.tudelft.nl/uuid:1532a009-8eac-4e52-883f-45ef411fa3f5","Taskforce management overstromingen, deelrapport planvorming","Smit, R.","TU Delft","2009","Dit deelrapport Planvorming gaat in op de voorbereiding op grootschalige overstromingen. Het beschrijft hoe de planvorming in Nederland kan worden ondersteund en gestructureerd en hoe de afstemming tussen de betrokken bestuurlijke niveaus kan worden zeker gesteld. Het rapport Capaciteitenanalyse voor de taak1 grootschalige evacuatie waarin het nationale beleid is vastgelegd, is daarbij mede uitgangspunt. Een afzonderlijke bijlage (A) gaat in op de werkwijze van het operationele besluitvormingsproces grootschalige overstromingen, bekend als het programma van de driedaagsen. Het doorlopen van het proces bleek al een belangrijke bijdrage aan een goede samenwerking te leveren; het is daarmee een programma dat in de toekomst kan worden ingezet. Het programma is er op gericht de juiste dingen in de planning te doen, niet om een dik plan af te leveren, dat leidt tot planfixatie of het wordt door niemand gebruikt op het moment dat het nodig is. Het koppelvlak, de samenwerking en interactie, tussen nationaal en de regios is de kritische succesfactor, dit aspect komt uitgebreid in het rapport aan bod. In een bijlage (B) worden de elementen die het koppelvlak bepalen beschreven.","overstroming; watersnood; rampenbeheersing","nl","report","Task force Management Overstromingen (TMO)","","","","","","","","","","","","",""
"uuid:147f0aa6-3146-45a0-86c7-24d6cd8ae2e0","http://resolver.tudelft.nl/uuid:147f0aa6-3146-45a0-86c7-24d6cd8ae2e0","Statistical Approach in Power Cables Diagnostic Data Analysis","Cichecki, P.; Jongen, R.A.; Gulski, E.; Smit, J.J.; Quak, B.; Petzold, F.; De Vries, F.","","2008","","cable insulation; data analysis; partial discharges; statistical analysis","en","journal article","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:f93c0b2f-fe53-4568-9b0e-fa18b61b27b3","http://resolver.tudelft.nl/uuid:f93c0b2f-fe53-4568-9b0e-fa18b61b27b3","On-site Testing and PD Diagnosis of High Voltage Power Cables","Gulski, E.; Cichecki, P.; Wester, F.; Smit, J.J.; Bodega, R.; Hermans, T.J.W.H.; Seitz, P.P.; Quak, B.; De Vries, F.","","2008","In addition to after-laying of new-installed high voltage (HV) power cables the use of on-site non-destructive on-site testing and diagnosis of service aged power cables is becoming an important issue to determine the actual condition of the cable systems and to determine the future performances. In this paper based on field experience an overview is presented on on-site testing and partial discharge diagnosis of HV power cables with regard to on-site testing methods: energizing, diagnostic aspects, possibilities and implications for new and service aged power cables.","high voltage power cables; on-site testing; ac over-voltages; partial discharges; diagnosis; condition assessment","en","journal article","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:3c074aca-38b0-4a8d-babc-5b4adb3e852a","http://resolver.tudelft.nl/uuid:3c074aca-38b0-4a8d-babc-5b4adb3e852a","Urbanism on Track: Application of tracking technologies in urbanism","Van der Hoeven, F.D.; Van Schaick, J.; Van der Spek, S.C.; Smit, M.G.J.","","2008","Tracking technologies such as GPS, mobile phone tracking, video and RFID monitoring are rapidly becoming part of daily life. Technological progress offers huge possibilities for studying human activity patterns in time and space in new ways. Delft University of Technology (TU Delft) held an international expert meeting in early 2007 to investigate the current and future possibilities and limitations of the application of tracking technologies in urban design and spatial planning. This book is the result of that expert meeting. Urbanism on Track introduces the reader to the basics of tracking research and provides insight into its advantages above other research techniques. But it also shows the bottlenecks in gathering and processing data and applying research results to real-life problems. Urbanism on Track showcases tracking experiments in urban studies, planning and design – from pedestrian navigation in Austria to Danish field tests, from TU Delft's Spatial Metro project to MIT's Real Time Rome and last but not least the Sense of the City project realised in Eindhoven. Urbanism on Track discusses the relevance of tracking for policy making, the possibilities of a new cartography and the implementation of tracking technologies in urban design and planning. This makes Urbanism on Track a unique book, setting the agenda for the structural embedment of research using tracking technologies in urbanism.","urbanism; tracking technologies; gps","en","book","IOS Press","","","","","","","","Architecture","Urbanism","","","",""
"uuid:165d11d6-aea3-4ae4-85be-8bf24f676d66","http://resolver.tudelft.nl/uuid:165d11d6-aea3-4ae4-85be-8bf24f676d66","Street-level desires, Discovering the city on foot: Pedestrian mobility and the regeneration of the European city centre","Van der Hoeven, F.D.; Van der Spek, S.C.; Smit, M.G.J.","Tan, R.E. (contributor)","2008","Pedestrian mobility and the regeneration of the European city centre. Cities can be chaotic and confusing places at the best of times – even for local people! Spatial Metro, a project largely funded by the EU, aims to make city visits more enjoyable for pedestrians by making cities easier to navigate, easier to walk around and easier to understand and appreciate. This is achieved in various ways, including illuminating characteristic buildings, providing ‘metro style’ maps as well as appropriate information and signposting for pedestrians and the application of GPS technology. Together with municipalities and universities, five cities (Norwich, Bristol, Rouen, Koblenz and Biel/Bienne) in North West Europe have carried out pilot studies and exchanged experiences. In this publication, their findings are shared with the reader.","urban renaissance; pedestrian mobility; public space; urban design; interreg; norwich; rouen; koblenz; bristol","en","book","Booksurge","","","","","","","","Architecture","Urbanism","","","",""
"uuid:07a875de-0dee-411d-987a-b4af4308c523","http://resolver.tudelft.nl/uuid:07a875de-0dee-411d-987a-b4af4308c523","Naar een Cyclisch Iteratief Ontwerpproces en Ontwerpomgeving","Smit, M.W.","Eekhout, A.C.J.M. (promotor)","2008","","","nl","doctoral thesis","","","","","","","","","Architecture and The Built Environment","","","","",""
"uuid:8c762a21-7f8e-4bbb-89e4-8814a9a62aea","http://resolver.tudelft.nl/uuid:8c762a21-7f8e-4bbb-89e4-8814a9a62aea","Upscaling of pipe tensioners","Smit, A.L.","","2008","","","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:573435a5-cc50-4241-a773-7b3c3dc7c78f","http://resolver.tudelft.nl/uuid:573435a5-cc50-4241-a773-7b3c3dc7c78f","Upscaling of pipe tensioners (summary)","Smit, A.L.","","2008","","","","master thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:41b3fb06-61fe-4ae5-ade3-3ac39dfc928b","http://resolver.tudelft.nl/uuid:41b3fb06-61fe-4ae5-ade3-3ac39dfc928b","Topology optmization in engineering; development of a tool for 3D topology optimization in ANSYS (summary)","Smit, A.L.","","2007","","Design assignment","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:38d02ec6-7aa4-43d9-834b-d930966f399a","http://resolver.tudelft.nl/uuid:38d02ec6-7aa4-43d9-834b-d930966f399a","Morsvoorkoming bij grijperoverslag. Een inventarisatie van de mogelijkheden (summary)","Smit, A.L.","","2007","","","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:b61e9042-b093-439a-a8a0-f29501a188e2","http://resolver.tudelft.nl/uuid:b61e9042-b093-439a-a8a0-f29501a188e2","Topology optmization in engineering; development of a tool for 3D topology optimization in ANSYS","Smit, A.L.","","2007","","Design assignment","","report","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:eb9461ce-1e1c-44b9-ad79-8250f5a23092","http://resolver.tudelft.nl/uuid:eb9461ce-1e1c-44b9-ad79-8250f5a23092","Dielectric interfaces in DC constructions: Space charge and polarization phenomena","Morshuis, P.H.F.; Bodega, R.; Fabiani, D.; Montanari, G.C.; Dissado, L.A.; Smit, J.J.","","2007","Interfaces between dielectrics are considered one of the weakest parts of an insulation system but their behavior under electrical stress is not yet completely understood. In particular, when a dc voltage is applied, the electric field distribution at the interface is quite difficult to predict. This is mainly due to the accumulation of internal charge, which distorts the initial Laplacian field. To shed some new light on this topic, space charge measurements were performed on two types of coaxial XLPE-EPR interfaces. A numerical procedure, based on the Maxwell-Wagner theory for interfacial polarization, was developed for the estimation of the dynamic charge build-up at the interface. Experimentally obtained space charge profiles were compared to the calculated profiles. The limits of the Maxwell-Wagner model were assessed and the main parameters, which affect the interfacial polarization but which are not included in the model, were identified.","","en","conference paper","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:9e5d1418-6b30-4c4b-acb2-fa40f2ad0043","http://resolver.tudelft.nl/uuid:9e5d1418-6b30-4c4b-acb2-fa40f2ad0043","Calculation and measurement of space charge in MV-size xxtruded cables systems under load conditions","Morshuis, P.H.F.; Bodega, R.; Fabiani, D.; Montanari, G.C.; Dissado, L.A.; Smit, J.J.","","2007","A load current in dc high voltage cables results in a temperature drop across the insulation and hence a radial distribution of the insulation conductivity is found. Direct consequence is an accumulation of space charge in the bulk of the nsulation, that may significantly affect its reliability. This phenomenon was modeled in terms of the macroscopic properties of the cable insulation and a numerical procedure was developed for the calculation of the time-dependent space charge and electric field in extruded-type cables. Results of calculations were compared to those of space charge measurements performed on MV-size XLPE cables at different values for the temperature drop. The analysis of the results indicates that the space charge induced by the temperature drop is measurable and that its magnitude and location can be reasonably well estimated by means of the proposed numerical procedure. Moreover, different space charge accumulation mechanisms could be distinguished taking into account the knowledge obtained of the space charge distribution induced by the temperature drop.","","en","conference paper","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:1366ad76-1cff-40c3-8e82-74f87f7fe962","http://resolver.tudelft.nl/uuid:1366ad76-1cff-40c3-8e82-74f87f7fe962","Morsvoorkoming bij grijperoverslag. Een inventarisatie van de mogelijkheden","Smit, A.L.","","2007","","","","report","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:03ab8ef6-121e-4173-8345-321da8ab20f9","http://resolver.tudelft.nl/uuid:03ab8ef6-121e-4173-8345-321da8ab20f9","Insulation Diagnosis of High Voltage Power Cables","Gulski, E.; Meijer, S.; Cichecki, P.; Smit, J.J.; Seitz, P.P.; Petzold, F.; De Vries, F.","","2007","","","en","conference paper","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:78fecb4c-211d-4ccc-a036-b19c337e0d3d","http://resolver.tudelft.nl/uuid:78fecb4c-211d-4ccc-a036-b19c337e0d3d","Morsvoorkoming bij grijperoverslag. Een inventarisatie van de mogelijkheden (summary)","Smit, A.L.","","2007","","","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:dbe89986-fc34-453f-8c09-ac179398632e","http://resolver.tudelft.nl/uuid:dbe89986-fc34-453f-8c09-ac179398632e","Rechargeable power supply","Den Uijl, S.; Bouman, C.; Smit, W.","","2006","The invention relates to a rechargeable power supply suitable to be used in a battery-operated device comprising at least one supercapacitor and at least a first and a second DC-DC converter connected in series, wherein the supercapacitor is connectable to an entry of the first DC-DC converter and the device is connectable to an exit of the second DC-DC converter.","","en","patent","European Patent Office","","","","","","","","Delft University of Technology","","","","",""
"uuid:10c917e6-b423-44f5-8e28-565786c2cf19","http://resolver.tudelft.nl/uuid:10c917e6-b423-44f5-8e28-565786c2cf19","The tectonic and metamorphic history of UHP basal gneisses and Blåhø- Surna cover complexes on Otrøy, Moldefjord, northern Western Gneiss Region, Norway: New insights into the pre-Scandian evolution of Iapetus and exhumation of (U)HP metamorphic terranes","Smit, M.A.","","2006","This MSc research is focussed upon two aspects. The first focus is to identify and classify tectonometamorphic signals and to establish their significance with respect to the dynamics of the Iapetus Ocean before late-Caledonian (Scandian) closure and concurrent (ultra-) high pressure ((U)HP) metamorphism. The second focus is to monitor mechanisms and processes that account for the exhumation of the (U)HP gneisses of the Western Gneiss Region. The island of Otrøy, Moldefjord, in the northern (UHP part) of the Western Gneiss Region, was chosen as the research area. On this island (U)HP gneisses, grt-peridotites and eclogites are exposed, that are overlain by a stack of unidentified allochthonous metapelites and metabasites. Correlative field studies indicate that the latter rocks (addressed in this study as the GK-Nappe) are part of the Blåhø-Surna nappe complex, a Norwegian equivalent of the Seve Nappe Complex in Sweden. The multidisciplinary research includes: (1) a field study into lithologies and structures, (2) light-microscopic analysis into microstructures and mineralogy, (3) quantitative Electron Microprobe (EMP) analysis into major element chemistry and (4) EMP U-Pb monazite geochronology. These data provide relevant information on the evolution of the nappe before Scandian collision. Furthermore, Comparison of these data to information on the UHP basal gneisses provides insight into the physical processes in both foot- and hanging wall complexes as a consequence to exhumation.","","","report","Utrecht University","","","","","","","","","","","","Molengraaff Fonds",""
"uuid:d10ce464-c694-4c76-a659-04e7a1755028","http://resolver.tudelft.nl/uuid:d10ce464-c694-4c76-a659-04e7a1755028","Decision support for maintenance managent of high voltage components","Quak, B.; Smit, J.J.; Gulski, E.","","2006","","","en","conference paper","Bandung Institute of Technology/IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:820e1704-6012-4a38-ab48-339e336ea629","http://resolver.tudelft.nl/uuid:820e1704-6012-4a38-ab48-339e336ea629","The upgrade of “Noble Ton van Langeveld to 1500 m waterdepth capability","Smit, Arjan","Pinkster, J.A. (mentor)","2006","","offshore","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:28e4b1a2-4fe6-426d-8c95-d4df43623aa2","http://resolver.tudelft.nl/uuid:28e4b1a2-4fe6-426d-8c95-d4df43623aa2","Space charge measurements on multi-dielectrics by means of the pulsed electroacoustic method","Bodega, R.; Morshuis, P.H.F.; Smit, J.J.","","2006","","","en","journal article","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:3c60e104-0f4b-4c10-b7c7-e48cfaa949ef","http://resolver.tudelft.nl/uuid:3c60e104-0f4b-4c10-b7c7-e48cfaa949ef","Application of statistical methods for making maintenance decisions within power utilities","Jongen, R.A.; Morshuis, P.H.F.; Gulski, E.; Smit, J.J.; Maksymiuk, J.; Janssen, A.L.J.","","2006","","statistics; reliability; insulation life; cable joints; epoxy-resin bushings","en","journal article","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:c08197b4-0df9-4e60-99ea-df85a69eb7e1","http://resolver.tudelft.nl/uuid:c08197b4-0df9-4e60-99ea-df85a69eb7e1","Codesign of an impulse generator and miniaturized antennas for IR-UWB","Bodega, R.; Morshuis, P.H.F.; Smit, J.J.","","2006","","","en","journal article","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:720bb2e2-4cb2-48d4-b14a-e4065c4d9dfa","http://resolver.tudelft.nl/uuid:720bb2e2-4cb2-48d4-b14a-e4065c4d9dfa","Comparison of the breakdown strength of N2, CO2 and SF6 using the extended up-and-down method","Meijer, S.; Smit, J.J.; Girodet, A.","","2006","","","en","conference paper","Bandung Institute of Technology/IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:72ba36af-3603-4636-b82c-9bdfb47617ad","http://resolver.tudelft.nl/uuid:72ba36af-3603-4636-b82c-9bdfb47617ad","Partial discharges at DC voltage: Their mechanism, detection and analysis","Morshuis, P.H.F.; Smit, J.J.","","2005","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:770d0357-ae82-44cd-9aaf-bbff401d000f","http://resolver.tudelft.nl/uuid:770d0357-ae82-44cd-9aaf-bbff401d000f","UHF defect evaluation in gas insulated equipment","Meijer, S.; Smit, J.J.","","2005","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:b7049f5e-79a3-4178-9189-f22a25f007c8","http://resolver.tudelft.nl/uuid:b7049f5e-79a3-4178-9189-f22a25f007c8","PD knowledge rules for insulation condition assessment of distribution power cables","Gulski, E.; Smit, J.J.; Wester, F.J.","","2005","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:48e39c59-3221-44d4-ad4c-c6494c903025","http://resolver.tudelft.nl/uuid:48e39c59-3221-44d4-ad4c-c6494c903025","Atomic-scale electronics in semiconductors","Smit, G.D.J.","Klapwijk, T.M. (promotor)","2004","A dopant atom in a semiconductor, the solid state analogue of a hydrogen atom, has a Bohr radius of several nanometers. Because this length scale is close to being accessible by modern nanolithography, detection and control of charge and spin in a semiconductor down to the level of individual dopant atoms is within reach and provides the unique opportunity to study, manipulate, and utilize a single atom's wave function. We have performed electrical transport measurements across epitaxial defect-free nanometer-sized Schottky diodes. These were formed by self-assembled CoSi2-islands on Si(111) and contacted with the tip of a scanning tunneling microscope (STM). Greatly enhanced conductance was observed in diodes which were small compared to the Debye length in the semiconductor. The observed behavior can be understood qualitatively from a decreased barrier width for smaller diodes. On highly doped substrates, we find that individual dopant atoms even dominate the transport characteristics of our nanometer sized devices, due to their random distribution in the space charge region. The ability to observe the energy levels of single dopant atoms is essential for experimental studies of individual wave functions in a semiconductor. Preliminary results in a fabrication method for nano-devices approaching the size regime necessary for the observation of single dopants demonstrate the feasibility of our STM-based measurement method for this purpose. The most straightforward means to address an individual impurity is manipulation of its wave function with a gate. As a first approach to this problem, we theoretically studied the effect of a homogeneous electric or magnetic field on the energy levels of shallow impurities in silicon, taking the bandstructure into account. Furthermore, we used a description as hydrogen-like impurities for accurate computation of energy levels and lifetimes up to large electric fields. A similar description was used in a realistic device geometry, in which a small nearby gate influences a single dopant atom. This knowledge is particularly important for the development of a dopant-atom based quantum computer.","nano-electronic devices; semiconductors at the atomic scale; discreteness of doping; single-dopant spectroscopy; crystal fields; stark effect; zeeman effect","en","doctoral thesis","OPTIMA Grafische Communicatie, Rotterdam","","","","","","","","Applied Sciences","","","","",""
"uuid:38c92e6f-8452-41f8-bf85-d059939d7d52","http://resolver.tudelft.nl/uuid:38c92e6f-8452-41f8-bf85-d059939d7d52","Group-theoretical analysis of double acceptors in a magnetic field: Identification of the Si:B+ ground state","Smit, G.D.J.; Rogge, S.; Caro, J.; Klapwijk, T.M.","","2004","","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:395f0447-677b-45be-9248-1cd3b7053ceb","http://resolver.tudelft.nl/uuid:395f0447-677b-45be-9248-1cd3b7053ceb","Stark effect in shallow impurities in Si","Smit, G.D.J.; Rogge, S.; Caro, J.; Klapwijk, T.M.","","2004","","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:9a890975-868c-4358-993c-727da441c80f","http://resolver.tudelft.nl/uuid:9a890975-868c-4358-993c-727da441c80f","Conductance distribution in nanometer-sized semiconductor devices due to dopant statistics","Smit, G.D.J.; Rogge, S.; Caro, J.; Klapwijk, T.M.","","2004","","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:17906929-b658-436e-8f80-5b074972a56c","http://resolver.tudelft.nl/uuid:17906929-b658-436e-8f80-5b074972a56c","Direct observation by resonant tunneling of the B+ level in a o-doped silicon barrier","Caro, J.; Vink, I.D.; Smit, G.D.J.; Rogge, S.; Klapwijk, T.M.; Loo, R.; Caymax, M.","","2004","","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:907b1fdc-a272-455b-8f29-11e7e60148a8","http://resolver.tudelft.nl/uuid:907b1fdc-a272-455b-8f29-11e7e60148a8","Gate-induced ionization of single dopant atoms","Smit, G.D.J.; Rogge, S.; Caro, J.; Klapwijk, T.M.","","2003","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:cc03f576-49a3-47c0-af37-c6d9fab01771","http://resolver.tudelft.nl/uuid:cc03f576-49a3-47c0-af37-c6d9fab01771","Scaling of nano-Schottky-diodes","Smit, G.D.J.; Rogge, S.; Klapwijk, T.M.","","2002","A generally applicable model is presented to describe the potential barrier shape in ultrasmall Schottky diodes. It is shown that for diodes smaller than a characteristic length lc (associated with the semiconductor doping level) the conventional description no longer holds. For such small diodes the Schottky barrier thickness decreases with decreasing diode size. As a consequence, the resistance of the diode is strongly reduced, due to enhanced tunneling. Without the necessity of assuming a reduced (non-bulk) Schottky barrier height, this effect provides an explanation for several experimental observations of enhanced conduction in small Schottky diodes.","Schottky diodes; nanotechnology; Schottky barriers","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Kavli Institute of Nanoscience","","","",""
"uuid:3720d580-7696-4711-bf84-8856063580c4","http://resolver.tudelft.nl/uuid:3720d580-7696-4711-bf84-8856063580c4","Enhanced tunneling across nanometer-scale metal–semiconductor interfaces","Smit, G.D.J.; Rogge, S.; Klapwijk, T.M.","","2002","We have measured electrical transport across epitaxial, nanometer-sized metal–semiconductor interfaces by contacting CoSi2 islands grown on Si(111) with the tip of a scanning tunneling microscope. The conductance per unit area was found to increase with decreasing diode area. Indeed, the zero-bias conductance was found to be ? 104 times larger than expected from downscaling a conventional diode. These observations are explained by a model, which predicts a narrower barrier for small diodes and, therefore, a greatly increased contribution of tunneling to the electrical transport.","semiconductor-metal boundaries; cobalt compounds; silicon; elemental semiconductors; tunnelling; metallic epitaxial layers; discontinuous metallic thin films; scanning tunnelling microscopy; Schottky diodes; Schottky barriers","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Kavli Institute of Nanoscience","","","",""
"uuid:a2a97a54-5de1-43c4-84a4-39b339ada80a","http://resolver.tudelft.nl/uuid:a2a97a54-5de1-43c4-84a4-39b339ada80a","Monitoring and diagnostic of transformer solid insulation","van Bolhuis, J.P.; Gulski, E.; Smit, J.J.","","2002","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:557d559c-7b17-4030-9377-3645acd32b3c","http://resolver.tudelft.nl/uuid:557d559c-7b17-4030-9377-3645acd32b3c","Low-loss, compact, and polarization independent PHASAR demultiplexer fabricated by using a double-etch process","den Besten, J.H.; Dessens, M.P.; Herben, C.G.P.; Leijtens, X.J.M.; Groen, F.H.; Leys, M.R.; Smit, M.K.","","2002","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:e5954401-b1bb-486b-ae32-e7d1753fb8a5","http://resolver.tudelft.nl/uuid:e5954401-b1bb-486b-ae32-e7d1753fb8a5","Standardization of on-line VHF PD measurements on turbo generators","van Breen, H.J.; Gulski, E.; Smit, J.J.; Verhaart, H.F.A.; de Leeuw, W.; Krieg-Wezelenburg, M.","","2002","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:f4f2b66d-4164-48da-87e7-e79c7619b6ce","http://resolver.tudelft.nl/uuid:f4f2b66d-4164-48da-87e7-e79c7619b6ce","Van landaanwinning naar kwelderwerken","Dijkema, K.; Nicolai, A.; de Vlas, J.; Smit, C.; Jongerius, H.; Nauta, H.","Alterra, Rijkswaterstaat dir. Noord Nederland","2001","Overzicht van het onderzoek naar de noodzaak en effectiviteit van kwelderwerken tot handhaving van de kustlijn van de Waddenzee na het besluit om deze niet meer te gebruiken voor landaanwinning. Zowel de morfologische als ecologische aspecten komen aan de orde. Technische informatie over opslibbing, rijzendammen en greppels.","kwelderwerken; aanslibbing; waddenkust","nl","report","Rijkswaterstaat, directive Noord Nederland","","","","","","","","","","","","kwelderwerken","53.43, 6.45"
"uuid:912eb45c-c2e9-4a1c-854f-0d81cd4cf1c1","http://resolver.tudelft.nl/uuid:912eb45c-c2e9-4a1c-854f-0d81cd4cf1c1","Advanced partial discharge diagnostic of MV power cable system using oscillating wave test system","Gulski, E.; Wester, F.J.; Smit, J.J.; Seitz, P.N.; Turner, M.","","2000","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:1cd832c8-6ebc-4028-84fd-45ba269c6f62","http://resolver.tudelft.nl/uuid:1cd832c8-6ebc-4028-84fd-45ba269c6f62","Fundamental aspects of PD patterns of on-line measurements on turbogenerators","Zondervan, J.P.; Gulski, E.; Smit, J.J.","","2000","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:3c1f3d47-e204-4f7a-b220-f903dc7918af","http://resolver.tudelft.nl/uuid:3c1f3d47-e204-4f7a-b220-f903dc7918af","Second World Congress on Safety of Transportation, 18-20 February 1998, proceedings imbalance between growth and safety?","Hengst, S.; Smit, K.; Stoop, J.A.","","1999","","verkeersveiligheid","en","book","Delft University Press","","","","","","","","Delft University of Technology","","","","",""
"uuid:60bf3513-76a8-4635-ab1e-fae5483c736a","http://resolver.tudelft.nl/uuid:60bf3513-76a8-4635-ab1e-fae5483c736a","Compact photonic integrated phase and amplitude controller for phased-array antennas","Stulemeijer, J.; van Vliet, F.E.; Benoist, K.W.; Maat, D.H.P.; Smit, M.K.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:695a7f9e-02eb-41ac-b4b6-ac8e58eae104","http://resolver.tudelft.nl/uuid:695a7f9e-02eb-41ac-b4b6-ac8e58eae104","InP-based spotsize converter for integration with switching devices","Stulemeijer, J.; Bakker, A.F.; Moerman, I.; Groen, F.H.; Smit, M.K.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:23e96ac4-a6bd-457f-b96f-16918362a4cb","http://resolver.tudelft.nl/uuid:23e96ac4-a6bd-457f-b96f-16918362a4cb","Experiences with digital analysis of discharges in high voltage components","Gulski, E.; Smit, J.J.; Brooks, R.; Turner, M.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:fb630f18-88ca-46e2-b465-32f6a6074b08","http://resolver.tudelft.nl/uuid:fb630f18-88ca-46e2-b465-32f6a6074b08","Minimization of the loss of intersecting waveguides in InP-based photonic integrated circuits","Bukkems, H.G.; Herben, C.G.P.; Smit, M.K.; Groen, F.H.; Moerman, I.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:15e73c0b-087e-4b8f-86c5-3fbe61d54715","http://resolver.tudelft.nl/uuid:15e73c0b-087e-4b8f-86c5-3fbe61d54715","Polarization independent dilated WDM cross-connect on InP","Herben, C.G.P.; Maat, D.H.P.; Leijtens, X.J.M.; Leys, M.R.; Oei, Y.S.; Smit, M.K.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:64d66477-f33f-4540-8166-63390dfb2f95","http://resolver.tudelft.nl/uuid:64d66477-f33f-4540-8166-63390dfb2f95","Crosstalk performance of integrated optical cross-connects","Herben, C.G.P.; Leijtens, X.J.M.; Maar, P.; Blok, H.; Smit, M.K.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:b14c401b-0482-464a-821b-cebef12923bc","http://resolver.tudelft.nl/uuid:b14c401b-0482-464a-821b-cebef12923bc","Schoon Schip","Smit, J.R.H.","","1999","","brandstofcellen; alternatieve voorstuwing","","report","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:a9e5203f-f4e7-4232-8a15-89b98fa4dab3","http://resolver.tudelft.nl/uuid:a9e5203f-f4e7-4232-8a15-89b98fa4dab3","Woonruimteverdeling in een veranderende woningmarkt: Huursubsidiebeheersing leegstandbestrijding, regionalisering","Priemus, H.; Van Rosmalen, B.; Kruidenberg, C.W.J.; Emmens, B.; van den Ham, A.R.A.; Smit, V.J.M.; Van Hemmen, P.; Heesen, J.; Eerland, G.","","1998","","woonruimteverdeling; woningmarkt; huursubsidie","nl","book","Delft University Press","","","","","","","","OTB Research Institute for the Built Environment","","","","",""
"uuid:a3fd98c7-e4f7-42f4-800c-6010effac4b9","http://resolver.tudelft.nl/uuid:a3fd98c7-e4f7-42f4-800c-6010effac4b9","Pattern analysis of partial discharges in SF6 GIS","Meijer, S.; Gulski, E.; Smit, J.J.","","1998","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:20d7f015-e963-4684-ac85-faf841a9776c","http://resolver.tudelft.nl/uuid:20d7f015-e963-4684-ac85-faf841a9776c","A low-loss 16-channel polarization dispersion-compensated PHASAR demultiplexer","Vreeburg, C.G.M.; Herben, C.G.P.; Leijtens, X.J.M.; Smit, M.K.; Groen, F.H.; van der Tol, J.J.G.M.; Demcester, P.","","1998","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:83c67678-fe73-4e6e-a030-510909b0632e","http://resolver.tudelft.nl/uuid:83c67678-fe73-4e6e-a030-510909b0632e","A compact integrated InP-based single-phasar optical crossconnect","Herben, C.G.P.; Vreeburg, C.G.M.; Maat, D.H.P.; Leijtens, X.J.M.; Oei, Y.S.; Groen, F.H.; Pedersen, J.W.; Demeester, P.; Smit, M.K.","","1998","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:20916ded-f012-4511-aa0c-0f6707b43304","http://resolver.tudelft.nl/uuid:20916ded-f012-4511-aa0c-0f6707b43304","Continue productie van 50 ton per maand amandelzuur door enzymatische synthese van mandelonitril gevolgd door chemokatalytische hydrolyse in een multipurpose-plant","Van den Bergh, S.A.; Friedrich, T.; Horneman, D.A.; Smit, M.","","1997","","(R)-amandelzuur; (R)-mandelonitril; (R)-oxynitrilase; enzymatische omzetting; zuur-gekatalyseerde hydrolyse; continue productie","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:ec54b16e-02ed-4012-a114-2690d87197d2","http://resolver.tudelft.nl/uuid:ec54b16e-02ed-4012-a114-2690d87197d2","De levensduur van de elektrische infrastructuur; hooggespannen verwachtingen","Smit, J.J.","","1997","","Intreerede","nl","public lecture","","","","","","","","","","","","","",""
"uuid:20544c3b-2656-4e50-95a4-859d41c8ff60","http://resolver.tudelft.nl/uuid:20544c3b-2656-4e50-95a4-859d41c8ff60","Chirping of an MMI-PHASAR demultiplexer for application in multiwavelength lasers","Herben, C.G.P.; Vreeburg, C.G.M.; Leijtens, X.J.M.; Blok, H.; Groen, F.H.; Moerman, I.; Pedersen, J.W.; Smit, M.K.","","1997","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:fa76c66c-9cb9-427c-9efa-8e13afca6882","http://resolver.tudelft.nl/uuid:fa76c66c-9cb9-427c-9efa-8e13afca6882","Experimental assessment of the reflection of passive multimode interference couplers","Erasme, D.; Spiekman, L.H.; Herben, C.G.P.; Smit, M.K.; Groen, F.H.","","1997","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:c7380ba4-e5cb-4252-a0c3-f2e813b82183","http://resolver.tudelft.nl/uuid:c7380ba4-e5cb-4252-a0c3-f2e813b82183","First InP-based reconfigurable integrated add-drop multiplexer","Vreeburg, C.G.M.; Uitterdijk, T.; Oei, Y.S.; Smit, M.K.; Groen, F.H.; Metaal, E.G.; Demeester, P.; Frankena, H.J.","","1997","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:a2b9d80d-8199-42a5-bebf-c58fcccf74f2","http://resolver.tudelft.nl/uuid:a2b9d80d-8199-42a5-bebf-c58fcccf74f2","Zwin '94 experiment: Meetopstelling en overzicht van alle meetresultaten","Visser, P.J.; Smit, M.J.; Snip, D.W.","","1996","Beschrijving van de meetopstelling en de meetresultaten van het zwin 1994 experiment alsmede de inhoud van het Zwin 1994 archief.","zwin; bresgroei; dijkdoorbraak; experiment","nl","report","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","51.370251, 3.369244"
"uuid:9f545a14-fa04-4a55-a60d-fb523e83c690","http://resolver.tudelft.nl/uuid:9f545a14-fa04-4a55-a60d-fb523e83c690","Het Zwin, successen en lessen: Bresgroeiexperimenten 6 en 7 oktober 1994 ""Het totale experiment geslaagd""","Bakker, W.T.; Van der Graaff, J.; Kraak, A.; Smit, M.J.; Snip, D.W.; Steetzel, H.J.; Visser, P.J.","Rijkswaterstaat","1996","In deze rapportage wordt een samenvatting van de achtergronden, de voorbereiding en het verloop van de beide proeven gegeven. Aan de successen die zijn behaald en de lessen die zijn geleerd, wordt aandacht besteed. De proeven vormen een onderdeel van het onderzoek naar dijkdoorbraakprocessen dat in opdracht van de Dienst Weg- en Waterbouwkunde van Rijkswaterstaat voor de Technische Adviescommissie voor de Waterkeringen wordt uitgevoerd. Omdat het in deze gevallen om onverdedigde zanddammen gaat, wordt in deze rapportage steeds de term 'damdoorbraak' in plaats van 'dijkdoorbraak' gebruikt.","dike breach; Zwin; dijkdoorbraak","nl","report","TU Delft, Department Hydraulic Engineering","","","","","","","","","","","","TAW/ENW","51.365863, 3.370401"
"uuid:77373e30-eb6d-4974-b3e0-16320c650fe3","http://resolver.tudelft.nl/uuid:77373e30-eb6d-4974-b3e0-16320c650fe3","Het Zwin, successen en lessen: Bresgroeiexperimenten op 6 en 7 oktober 1994","Bakker, W.T.; Van de Graaff, J.; Kraak, A.W.; Smit, M.J.; Snip, D.W.; Steetzel, H.J.; Visser, P.J.","","1996","Op 6 en 7 oktober 1994 hebben twee grootschalige damdoorbraakexperimenten plaatsgevonden in Het Zwin in Zee uwsch-Vlaanderen. Vooral het eerste experiment op 6 oktober heeft veel publicitaire aandacht getrokkcn. Op het beslissende ogenblik, het begin van de proef rondom het tijdstip van hoogwater, verliep deze proef niet volgens verwachting. Het doorbraakproces kwam slecht op gang. Uiteindelijk werd een bescheiden gat bereikt; de gatbreedte bedroeg aan het eind van de proef ongeveer 13 meter. Direct na de afloop van de proef op 6 oktober werd besloten de proef op 7 oktober te herhalen. Op 7 oktober verliep de proef volledig naar wens. In 1 uur tijd werd uiteindelijk een gatbreedte van ongeveer 41 meter bereikt. In deze rapportage wordt een samenvatting van de achtergronden, de voorbereiding en het verloop van de beide proeven gegeven. Aan de successen die zijn behaald en de lessen die z ijn geleerd, wordt aandacht besteed. De proeven vormen een onderdeel van het onderzoek naar dijkdoorbraakprocessen dat in opdracht van de Dienst Weg- en Waterbouwkunde van Rijkswaterstaat voor de Technische Adviescommissie voor de Waterkeringen wordt uitgevoerd. Omdat het in deze gevallen om onverdedigde zanddammen gaat, wordt in deze rapportage steeds de term 'damdoorbraak' in plaats van 'dijkdoorbraak' gebruikt.","breach; dune; dambreak","nl","report","TAW","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:58040c6e-8003-4e41-bb16-7606ddfda76b","http://resolver.tudelft.nl/uuid:58040c6e-8003-4e41-bb16-7606ddfda76b","De produktie van methanol uit koolstofdioxide, uit rookgas, en waterstof","Go, Y.S.Y.; De Haas, E.C.; Sakko, R.; Smit, J.R.N.","","1996","","absorptie; koolstofdioxide; methanolsynthese; rookgas","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:37a5ebe1-766e-42cf-9511-573882edc4b8","http://resolver.tudelft.nl/uuid:37a5ebe1-766e-42cf-9511-573882edc4b8","PHASAR-based WDM-devices: Principles, design and applications","Smit, M.K.; Van Dam, C.","","1996","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:c21d2a30-6198-44e2-b596-7796b8acaf06","http://resolver.tudelft.nl/uuid:c21d2a30-6198-44e2-b596-7796b8acaf06","S-matrix oriented CAD-tool for simulating complex integrated optical circuits","Leijtens, X.J.M.; Le Lourec, P.; Smit, M.K.","","1996","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:44990b26-9ec9-415a-90cf-d124b249738e","http://resolver.tudelft.nl/uuid:44990b26-9ec9-415a-90cf-d124b249738e","Monte Carlo renormalization of the 3D ising model: Analyticity and convergence","Blöte, H.W.J.; Heringa, J.R.; Hoogland, A.; Meyer, E.W.; Smit, T.S.","","1996","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:edc6537c-bb56-40cb-8767-1501665afa1f","http://resolver.tudelft.nl/uuid:edc6537c-bb56-40cb-8767-1501665afa1f","Design and realization of polarization independent phased array wavelength demultiplexers using different array orders for TE and TM","Spiekman, L.H.; Amersfoort, M.R.; De Vreede, A.H.; van Ham, F.P.G.M.; Kuntze, A.; Pedersen, J.W.; Demeester, P.; Smit, M.K.","","1996","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:1500b4cf-45c6-415b-9343-4aae5e140f8f","http://resolver.tudelft.nl/uuid:1500b4cf-45c6-415b-9343-4aae5e140f8f","Novel compact polarization converters based on ultra short bends","van Dam, C.; Spiekman, L.H.; van Ham, F.P.G.M.; Groen, F.H.; van der Tol, J.J.G.M.; Moerman, I.; Pascher, W.W.; Hamacher, M.; Heidrich, H.; Weinert, C.M.; Smit, M.K.","","1996","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:c58b7695-8a31-4911-94fd-8ce1022a6efa","http://resolver.tudelft.nl/uuid:c58b7695-8a31-4911-94fd-8ce1022a6efa","Zoet water in het Schelde-estuarium: Veranderingen in de saliniteit","Holland, A.M.B.; Smit, H.","Rijkswaterstaat","1994","","Schelde-estuarium; Zoet water","nl","report","RIKZ","","","","","","","","","","","","DGW-93.057",""
"uuid:47b78b3e-ddc6-4040-880c-a200ffcd2ec8","http://resolver.tudelft.nl/uuid:47b78b3e-ddc6-4040-880c-a200ffcd2ec8","Extremely small multimode interference couplers and ultrashort bends on InP by deep etching","Spiekman, L.H.; Oei, Y.S.; Metaal, E.G.; Green, F.H.; Moerman, I.; Smit, M.K.","","1994","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:92ad77a6-c4a7-4d41-ba9b-1359cfcfd50c","http://resolver.tudelft.nl/uuid:92ad77a6-c4a7-4d41-ba9b-1359cfcfd50c","Mach-Zehnder interferometer polarization splitter in InGaAsP/InP","Soldano, L.B.; de Vreede, A.I.; Smit, M.K.; Verbeek, B.H.; Metaal, E.G.; Green, F.H.","","1994","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:0950fa27-37b6-42f0-bf8d-067414064e16","http://resolver.tudelft.nl/uuid:0950fa27-37b6-42f0-bf8d-067414064e16","Een proces voor continue harding: Continue harding van monomere vetzuren","Abspoel, M.; Chin a Lien, H.; Van Doeland, D.; Dorsteen, M.; De Feber, M.; Gooijer, J.; Hoeksma, M.; Okhuijsen, B.; Raktoe, L.; Ramondt, M.; Reynders, A.; Schoneveld, W.; Schouten, T.; Smit, W.; Verheul, P.; De Vries, N.; G-groep najaar 1993 ","","1993","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University","","","","","","","2003-11-01","Applied Sciences","DelftChemTech","","","",""
"uuid:7a51b368-fb5a-4ded-b52a-c11e0fbc7d00","http://resolver.tudelft.nl/uuid:7a51b368-fb5a-4ded-b52a-c11e0fbc7d00","A normalized approach to the design of low-loss optical waveguide bends","Smit, M.K.; Pennings, E.C.M.; Blok, H.","","1993","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:1518e01e-59bc-44ea-bbde-08b3d1db2f7a","http://resolver.tudelft.nl/uuid:1518e01e-59bc-44ea-bbde-08b3d1db2f7a","A long InGaAsP/InP waveguide section with small dimensions","Verboom, P.; Oei, Y.S.; Pennings, E.; Smit, M.; van Uffelen, J.; van Brug, H.; Moerman, I.; Coudenijs, G.","","1992","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:09bd0ca8-096b-44b1-9345-d65270bd32e5","http://resolver.tudelft.nl/uuid:09bd0ca8-096b-44b1-9345-d65270bd32e5","Planar monomode optical couplers based on multimode interference effects","Soldano, L.B.; Veerman, F.B.; Smit, M.K.; Verbeek, B.H.; Dubost, A.H.; Pennings, E.C.M.","","1992","","","","journal article","IEEE","","","","","","","","","","","","",""
"uuid:b281f5a0-b233-424a-9a49-4a9a3ead7b4c","http://resolver.tudelft.nl/uuid:b281f5a0-b233-424a-9a49-4a9a3ead7b4c","An optical passive 3-dB TMI-coupler with reduced fabrication tolerance sensitivity","Veerman, F.B.; Schalkwijk, P.J.; Pennings, E.C.M.; Smit, M.K.; Verbeek, B.H.","","1992","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:578ddf8d-fc6d-4d86-937e-756ce6a8d8c8","http://resolver.tudelft.nl/uuid:578ddf8d-fc6d-4d86-937e-756ce6a8d8c8","Integrated optics in silicon-based aluminum oxide","Smit, M.K.","Acket, G.A. (promotor)","1991","","geïntegreerde optica; optoëlectronica","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:11ff4892-2732-4b12-a317-77651b7fde94","http://resolver.tudelft.nl/uuid:11ff4892-2732-4b12-a317-77651b7fde94","Four-channel integrated-optic wavelength demultiplexer with weak polarization dependence","Vellekoop, A.R.; Smit, M.K.","","1991","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:6652ac6e-539b-480d-9f49-449b68b69122","http://resolver.tudelft.nl/uuid:6652ac6e-539b-480d-9f49-449b68b69122","A small-size polarization splitter based on a planar optical phased array","Vellekoop, A.R.; Smit, M.K.","","1990","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:7ec30512-e532-45fa-89d7-a0643cdb689e","http://resolver.tudelft.nl/uuid:7ec30512-e532-45fa-89d7-a0643cdb689e","Onderzoek naar decentralisatie mogelijkheden binnen het rederijbedrijf","Smit, M.G.","","1988","","","","other","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:eae459a3-3fff-4b31-8e8e-516b52fd2b3a","http://resolver.tudelft.nl/uuid:eae459a3-3fff-4b31-8e8e-516b52fd2b3a","Onderzoek naar decentralisatie mogelijkheden binnen het rederijbedrijf","Smit, M.G.","","1988","","","","other","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:b48ff46d-c52a-4d0a-a7c8-99375062b2c2","http://resolver.tudelft.nl/uuid:b48ff46d-c52a-4d0a-a7c8-99375062b2c2","Een 100 MWe centrale op basis van verbranding van steenkool in een PFBC met regeneratieve zwavelafvangst","Smit, N.G.M.; Velthuis, H.W.","","1987","Document(en) uit de collectie Chemische Procestechnologie.","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:c9ad2bcc-54e0-48fd-820f-411e5e9ff911","http://resolver.tudelft.nl/uuid:c9ad2bcc-54e0-48fd-820f-411e5e9ff911","Waarheden omtrent kustgedrag","Bakker, W.T.; Smit, E.","Rijkswaterstaat","1986","Deze nota geeft de tekst van een lezing, gegeven door de eerste auteur bij de start van ""Taakgroep 100"" van het project ""Kustgenese"" op 27 januari 1986. Oudere en nieuwere ""waarheden"" omtrent het kustgedrag, geponeerd door diverse deskundigen worden geevalueerd, zoals de ""Waarheid van Edelman"": ""holle kusten zanden aan en bolle eroderen"". Geconstateerd wordt, dat het bijzonder moeilijk zal zijn het ongelijk van deze waarheid voor de schone Hollandse kust aan te tonen. Deze ""waarheid"" is gesimuleerd in een mathematisch model in appendix A. De tekst in deze appendix is van de tweede auteur, vervaardigd aan de hand van aantekeningen en berekeningen van de eerste. Geconstateerd wordt verder, dat vermoedelijk de snelste manier om een redelijke voorspelling van het kustgedrag in het kader van Taakgroep 1-- te maken de bestudering van het Jarkusbestand is met behulp van Kalman - filtering.","morfologie; aanzanding; erosie","nl","report","Rijkswaterstaat, RIKZ","","","","","","","","","","","","",""
"uuid:46943ff6-24ce-4a60-af4d-dfe0be6e8da2","http://resolver.tudelft.nl/uuid:46943ff6-24ce-4a60-af4d-dfe0be6e8da2","Het Mobil/Badger ethylbenzeen proces","Van Kwartel, R.; Smit, L.","","1986","Document uit de collectie Chemische Procestechnologie","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:07cc726d-8704-4305-b675-eca0951b5c58","http://resolver.tudelft.nl/uuid:07cc726d-8704-4305-b675-eca0951b5c58","De berging van de Castillo de Salas","Smit, M.","","1986","","diversen","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:7d4fb06c-4a45-4fea-b844-b8aabd99d1dd","http://resolver.tudelft.nl/uuid:7d4fb06c-4a45-4fea-b844-b8aabd99d1dd","Operationele prestatie en conditie (opec) analyse","Smit, M.","","1986","","","","other","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:73d05460-84c2-4f92-8fe3-ee35fed4ebe7","http://resolver.tudelft.nl/uuid:73d05460-84c2-4f92-8fe3-ee35fed4ebe7","Ontwerp van een laboratoriumopstelling voor een extractieproces met behulp van hexaan","Smit, B.","","1985","Document uit de collectie Chemische Procestechnologie","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:b9aaeef5-8370-43a3-a7b7-3dfb742373ea","http://resolver.tudelft.nl/uuid:b9aaeef5-8370-43a3-a7b7-3dfb742373ea","Hefsystemen van jack-ups","Smit, M.","","1985","","offshore; diversen","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:0a2571fb-245d-4e53-8220-6e18a497d396","http://resolver.tudelft.nl/uuid:0a2571fb-245d-4e53-8220-6e18a497d396","Geocoding: The spatial dimension of an information system for the MVRO","Van Est, J.; Smit, L.","","1981","One of the major Droblems of research and planning and policy making is the lacking of the availability of information. Modern analysis is of ten hampered by this, due to the fuzzy locational identification of the data. Many variables and attributes are only measured (i.e. available) on geographical areas of different sizes, which are overlapping as well. If the data are available and if they can be linked to each other then it still is a very time consuming process to derive the required information. The above reveals some evidence that gives rise to a new line of thinking, in which the existence of a spatial dimension is accounted for: geocoding. The spatial structure, described by points (addresses) and segments (streets) and polygons (zonal areas), can be combined with locational data files within the framework of a spatial oriented information system. The existing data files remain the source of information and the segments of the network structure function as data carriers for manipulating the data. Hith new methods and techniques administrative data systems can now be used in a much more efficient and decentralized way. Started in 1967 in New Haven, USA, many countries are benefitting from this new concept. For that reason the Ministry of Housing and Physical Planning wanted to draw up an inventory of possible geocoding methods. In 1979 and 1980 the project has been carried out. In this paper a summary is presented.","","en","book","Delftsche Uitgevers Maatschappij B.V.","","","","","","","","Delft University of Technology","","","","",""
"uuid:a3c3f93c-bef6-4795-be88-96477c79b230","http://resolver.tudelft.nl/uuid:a3c3f93c-bef6-4795-be88-96477c79b230","Thresholds for the visual perception of position deviations and motion","Smit, J.","","1978","During a visual approach to landing a pilot uses cues in the visual scene for the control of aircraft attitude and flight path. The accuracy with which some relevant display elements can ""be set at a desired, nominal, position was determined in an experiment via the phychophysical ""method of adjustment"". Furthermore relevant literature with respect to the thresholds for the perception of motion was reviewed.","Pilot performance; Motion perception; Visual perception; Threshold (perception); Aircraft landing; Manual control; Display devices; Tracking (position); Visual tasks; Visual fields; Psychophysiology; Analogue simulation","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:da1b7317-4b14-43e3-87d3-a36e49e0bbc4","http://resolver.tudelft.nl/uuid:da1b7317-4b14-43e3-87d3-a36e49e0bbc4","Scheiding van etheen en propeen uit een gasmengsel","Smit, H.; Lafort, G.J.J.","","1977","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:9dc75c2e-76ad-4599-984e-b62d39d71246","http://resolver.tudelft.nl/uuid:9dc75c2e-76ad-4599-984e-b62d39d71246","Pilot workload analysis based upon in-flight physiological measurements and task analysis methods","Smit, J.","","1976","","","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:c15fa19a-a1e3-4797-a4c1-3072bbead50b","http://resolver.tudelft.nl/uuid:c15fa19a-a1e3-4797-a4c1-3072bbead50b","Orderbegeleiding werf, werk gedaan bij IHC Smit B.V., Int","Smit, J.D.","","1973","","scheepsbouw; werfinrichting","","master thesis","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Design, Production and Operation","","",""
"uuid:e252ec3b-05b1-411f-ab40-dd2a28542a99","http://resolver.tudelft.nl/uuid:e252ec3b-05b1-411f-ab40-dd2a28542a99","Thermische ontleding van calciumnitraat in een fluid-bed reaktor","Smit, A.","","1971","Document(en) uit de collectie Chemische Procestechnologie.","","nl","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:65e87c6d-a8b0-4d17-82cb-3512a19080c5","http://resolver.tudelft.nl/uuid:65e87c6d-a8b0-4d17-82cb-3512a19080c5","Bereiding van allylalkohol uit propeen via acroleïne","Borsboom, J.; Smit, H.C.; Zuiderwijk, J.J.M.","","1970","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:3ef88a27-d1b4-4078-a0d7-cb7196019c73","http://resolver.tudelft.nl/uuid:3ef88a27-d1b4-4078-a0d7-cb7196019c73","Considerations of propeller layout from the engine-builder’s point of view","Smit, J.A.","","1968","","resistance & propulsion","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:db8f9d01-287a-4aba-891b-66778266ea99","http://resolver.tudelft.nl/uuid:db8f9d01-287a-4aba-891b-66778266ea99","Zwavelzuurfabricage","Margarita, R.E.; Smit, W.P.","","1966","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:aee233e9-9698-41e3-bd84-d163344366a0","http://resolver.tudelft.nl/uuid:aee233e9-9698-41e3-bd84-d163344366a0","Bereiding van 80% salpeterzuur door hoge druk absorptie van nitreuze gassen in water","Goossens, A.G.; Smit, G.J.","","1965","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:4be50bed-fc61-473e-8f05-24394da90d96","http://resolver.tudelft.nl/uuid:4be50bed-fc61-473e-8f05-24394da90d96","Methylmercaptaan","Smit, A.M.","","1961","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:97a23ff2-e028-49dd-b56f-3dd39d27ba83","http://resolver.tudelft.nl/uuid:97a23ff2-e028-49dd-b56f-3dd39d27ba83","Verslag fabrieksschema salpeterzuurfabriek","Smit, B.C.H.J.","","1960","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:b828deb4-b899-45ba-b91f-1fbfab99a298","http://resolver.tudelft.nl/uuid:b828deb4-b899-45ba-b91f-1fbfab99a298","Theorie en praktijk van het zinken op stroom","Smit, N.","Prins, J.E. (contributor); TU Delft","1960","Op initiatief van de commissie Bodembezinking van de Ned. Ver. Kust- en Oeverwerken werd een studie opgezet waarbij zowel theorie als praktijk en waterloopkundig modelonderzoek een rol hebben gespeeld. Op grond van daze studie en bij de toepassing in de praktijk opgedane ervaring kan thans worden gezegd, dat het zinken op stroom technisch gezien een reële uitvoeringsmogelijkheid biedt voor het aanbrengen van de klassieke bodembescherming.","zinkstuk; bodembescherming; stroming","nl","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:4aa591e6-9f9a-4226-99c4-832dfa2c0563","http://resolver.tudelft.nl/uuid:4aa591e6-9f9a-4226-99c4-832dfa2c0563","De linolzuren en de oxydatie van onverzadigde vetzuren door organische perzuren","Smit, W.C.","Böeseken, J. (promotor)","1929","","","nl","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""