"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:6d3dd4f1-0f24-4316-ab7c-57190e516042","http://resolver.tudelft.nl/uuid:6d3dd4f1-0f24-4316-ab7c-57190e516042","Optimal Ship Fuel Selection under Life Cycle Uncertainty","Zwaginga, J.J. (TU Delft Ship Design, Production and Operations); Lagemann, Benjamin (Norwegian University of Science and Technology (NTNU); SINTEF Ocean); Erikstad, Stein Ove (Norwegian University of Science and Technology (NTNU)); Pruyn, J.F.J. (TU Delft Ship Design, Production and Operations; Rotterdam University of Applied Sciences)","","2024","Shipowners need to prepare for low-emission fuel alternatives to meet the IMO 2050 goals. This is a complex problem due to conflicting objectives and a high degree of uncertainty. To help navigate this problem, this paper investigates how methods that take uncertainty into account, like robust optimization and stochastic optimization, could be used to address uncertainty while taking into account multiple objectives. Robust optimization incorporates uncertainty using a scalable measure of conservativeness, while stochastic programming adds an expected value to the objective function that represents uncertain scenarios. The methods are compared by applying them to the same dataset for a Supramax bulk carrier and taking fuel prices and market-based measures as uncertain factors. It is found that both offer important insights into the impact of uncertainty, which is an improvement when compared to deterministic optimization, that does not take uncertainty into account. From a practical standpoint, both methods show that methanol and LNG ships allow a cheap but large reduction in emissions through the use of biofuels. More importantly, even though there are limitations due to the parameter range assumptions, ignoring uncertainty with respect to future fuels is worse as a starting point for discussions.","ship design; alternative fuel; energy system selection; uncertainty; optimization; robust; stochastic","en","journal article","","","","","","","","","","","Ship Design, Production and Operations","","",""
"uuid:01c64b60-8248-4110-b798-ece9e42bee1b","http://resolver.tudelft.nl/uuid:01c64b60-8248-4110-b798-ece9e42bee1b","Dealing with Cross-Sectoral Uncertainty: A Case Study on Governing Uncertainty for Infrastructures in Transition","Røsok, O.P. (TU Delft Organisation & Governance); de Bruijne, M.L.C. (TU Delft Organisation & Governance); Veeneman, Wijnand (TU Delft Organisation & Governance)","","2023","The interdependencies between infrastructures are growing. Engineering decision making that earlier was largely confined to a specific sector now requires more and more understanding of how systems interact: a system-of-systems perspective. The article analyzes the effect of that added complexity in a single case study in de Zuid-As, Amsterdam, in the Netherlands, and relates the findings to the literature on engineering decision making and project management in complex projects. The article concludes that cross-sectoral engineering decision making has an additional level of complexity that requires governance of uncertainty. Despite this challenge being a well-known challenge among infrastructure operators, it is still not recognized for its importance, and it seems to be a neglected element in collaboration. Key is an open approach in the early stages that goes beyond classic cooperative decision making in engineering and project management environments.","cross-sectoral; interdependency; infrastructures; uncertainty; governance; infrastructure projects","en","journal article","","","","","","","","","","","Organisation & Governance","","",""
"uuid:e3579e62-7665-4e61-b8c4-3a208ca88695","http://resolver.tudelft.nl/uuid:e3579e62-7665-4e61-b8c4-3a208ca88695","Methods for Partial Discharge Calibration in Gas-Insulated Substations for HVDC Power Grids and Charge Evaluation Uncertainty","Mier Escurra, C. (TU Delft High Voltage Technology Group); Khamlichi, Abderrahim (Laboratorio Central Oficial de Electrotencia, Madrid); Dalstein, Matthieu (Super Grid Institute, Villeurbanne); Vidal, Jose Ramon (Laboratorio Central Oficial de Electrotencia, Madrid); Garnacho, Fernando (Laboratorio Central Oficial de Electrotencia, Madrid); Mor, Armando Rodrigo (Universitat Politécnica de Valencia); Vu-Cong, Thanh (Super Grid Institute, Villeurbanne)","","2023","Driven by the voltage increase in high-voltage direct current (HVDC) gas-insulated substations (GISs), novel methods are needed for partial discharge (PD) detection and monitoring. This article shows a PD calibration method for very-high-frequency (VHF) magnetic and electric sensors in GIS. The calibration method uncertainty is tested in three laboratories using a low-voltage (LV) test bench and a high-voltage (HV) full-scale GIS. In the LV test, the calibration method's linearity, signal-to-noise ratio (SNR), and pulsewidth were compared against a reference charge, resulting in an error of around ±10%. The HV test consisted of different artificial defects introduced in a full-scale GIS, resulting in errors of around ±30%. The uncertainty is attributed mainly to random noise, which is critical in the charge estimation method. The electric and magnetic sensor combination showed better results, especially in the full-scale GIS, where reflections play an important role. This research has been performed in the framework of the project Future Energy 19ENG02 of EURAMET, resulting in a calibration method with the potential to measure PD pulses and discriminate impulse interferences, giving an advantage over conventional and ultrahigh-frequency (UHF) methods.","calibration; GIS; partial discharges; uncertainty","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-05","","","High Voltage Technology Group","","",""
"uuid:fc35eeb5-7d40-4839-9828-e971277d6107","http://resolver.tudelft.nl/uuid:fc35eeb5-7d40-4839-9828-e971277d6107","Between flexibility and relativism: How students deal with uncertainty in sustainability challenges","Bohm, N.L. (TU Delft Urban Development Management); Klaassen, R.G. (TU Delft Policy & Implementation); van Bueren, Ellen (TU Delft Management in the Built Environment); den Brok, P. (Wageningen University & Research)","Reilly, Ger (editor); Murphy, Mike (editor); Nagy, Balazs Vince (editor); Jarvinen, Hannu-Matti (editor)","2023","Universities open their doors to society, inviting the complexity of the world to enter engineering education through challenge-based courses. While working on complex issues, engineering students learn to deal with different kinds of uncertainty: uncertainty about the dynamics of a real-world challenge, the knowledge gaps in the problem, or the conflicting perspectives amongst the people involved. Although we know from previous research that students are likely to encounter these uncertainties in sustainability challenges, which metacognitive strategies they use to deal with them is unclear. We interviewed nine MSc students at the end of a challenge-based course at a Dutch university of technology. We asked the students how they dealt with uncertainty in collaboration with the commissioner, their student team, and the teachers. The interviews were analyzed through grounded, consensus-based coding by two researchers. Preliminary results show students use three main strategies. First, the different perspectives from peers in their team inform the position of the student. Second, students find expectation management of the commissioner essential, yet students struggle with how to do this in a professional and timely way. Third, students frame the uncertainties they encounter as part of the learning process, which allows them to accept the possibility of failure. This study provides first insights in metacognitive uncertainty strategies and suggests those strategies should become a more prominent topic in coaching students. When uncertainty becomes an explicit part of challenge-based education, students learn to deal with both the known and unknown in the transition to a sustainable society.","challenge-based learning; metacognition; uncertainty; urban sustainability","en","conference paper","European Society for Engineering Education (SEFI)","","","","","Publisher Copyright: © 2023 SEFI 2023 - 51st Annual Conference of the European Society for Engineering Education: Engineering Education for Sustainability, Proceedings. All Rights Reserved.","","","","Management in the Built Environment","Urban Development Management","","",""
"uuid:ed997758-c6bc-48a0-86ad-454094be862b","http://resolver.tudelft.nl/uuid:ed997758-c6bc-48a0-86ad-454094be862b","Systematic errors observed in CryoSat-2 elevation swaths on mountain glaciers and their implications","Haacker, J.M. (TU Delft Physical and Space Geodesy); Wouters, B. (TU Delft Physical and Space Geodesy); Slobbe, D.C. (TU Delft Physical and Space Geodesy)","","2023","Our awareness of ice caps’ and mountain glaciers’ sensitivity to climate change has driven major advances in the application of remote sensing techniques during the past decade. Regarding ESA’s SARIn altimeter CryoSat-2, processing the full waveform to generate swaths of elevation estimates has become standard practice in regions of complex topographies. This technique provides information on areas where we would be blind otherwise. In this article, we discuss systematic errors and analyze their impact on surface elevation measurements and change rates of two test areas. In particular, we focus on periodically occurring errors in elevation swaths, caused by the superposition of coherent signals from range-ambiguous surfaces. They can lead to measurement errors in excess of 10m, affect most measurements in mountainous regions, are difficult to exclude with established post-processing techniques, and occur repeatedly for satellite revisits introducing a 369-day periodicity—difficult to distinguish from the annual cycle. We show a correlation between derived elevation swaths and the sensor view angle and explore the influence of common data exclusion choices on higher-level products. Our results indicate that these systematic errors hold a substantial share of the error budget and that the choice of thresholds impacts higher-level products. We conclude that error correlations need to be considered to characterize the data accuracy. With the established data editing strategies, systematic errors prevent resolving seasonal mass changes of single mountain glacier basins and impact aggregates over larger areas or longer periods.","Coherence; CryoSat-2; error; Ice; mountain glacier; Remote sensing; resolution; Rough surfaces; Spatial resolution; Surface roughness; Surface topography; swath; Systematics; uncertainty","en","journal article","","","","","","","","","","","Physical and Space Geodesy","","",""
"uuid:442e0267-4b34-416c-a1dd-26f7dbfc10ac","http://resolver.tudelft.nl/uuid:442e0267-4b34-416c-a1dd-26f7dbfc10ac","IEC 60270 Calibration Uncertainty in Gas-Insulated Substations","Mier Escurra, C. (TU Delft High Voltage Technology Group); Mor, A. R. (Universitat Politécnica de Valencia); Vaessen, P.T.M. (TU Delft High Voltage Technology Group)","","2023","Partial discharge (PD) measurements in gasinsulated substations (GIS) are tested according to the standard IEC 60270. This “conventional” PD test method applies to electrically small devices. The equipment size increases the resonance, and attenuation, contributing to the total uncertainty. Additionally, when an ultra-high frequency (UHF) sensor is used as a coupling capacitor, the calibrator and PD pulse duration difference increase the measurement uncertainty. In this paper, the IEC method, using an external capacitor coupler and a UHF sensor, is simulated and tested in a full-scale GIS. The results show the uncertainty dependency with the IEC 60270 filter bandwidth. With proper measures, the UHF sensor correlates with the external coupling capacitor, resulting in a reasonable charge estimation for a 25-meter-long GIS. Knowing the calibration limits is critical to estimate the PD charge uncertainty.","partial discharge; IEC 60270; calibration; uncertainty; UHF","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.","","2024-01-14","","","High Voltage Technology Group","","",""
"uuid:e3cac856-57c7-4dc1-8228-91c4c49d6098","http://resolver.tudelft.nl/uuid:e3cac856-57c7-4dc1-8228-91c4c49d6098","Towards more credible models in catchment hydrology to enhance hydrological process understanding: Preface","Refsgaard, Jens Christian (Geological Survey of Denmark and Greenland); Mai, Juliane (University of Waterloo; Helmholtz Centre for Environmental Research–UFZ; Center for Scalable Data Analytics and Artificial Intelligence); Hrachowitz, M. (TU Delft Water Resources); Jain, Sharad K. (Indian Institute of Technology Roorkee); Stisen, Simon (Geological Survey of Denmark and Greenland)","","2023","Catchment modelling has undergone tremendous developments during the past decades. In the 1970s, the focus was on simulation of catchment runoff with process descriptions and data inputs being lumped to the catchment scale. Later developments included spatially distributed models allowing data inputs and hydrological processes to be simulated at model grid scale, that is, much finer than catchment scale. These models were able to explicitly simulate various processes such as soil moisture, evapotranspiration, groundwater and surface runoff. With the advancements in remote sensing technology and availability of high-resolution data, increased attention has in recent years been given to enhancing the capability of catchment models to reproduce spatial patterns and in this way improve our understanding of hydrological processes and the physical realism of catchment models. This development process has involved a wide spectrum of different aspects in the modelling process, reaching from an improved understanding of uncertainties in data, model parameters and model structures to new protocols for good modelling practices in water management. Recognizing the important role of biodiversity and social aspects, hydrologists are now extending the scope of their models to capture the interactions between water, biota and human social systems.
This special issue (SI) of hydrological processes is the result of an open call for abstracts announced in October 2020. The SI comprises a collection of 14 papers authored and co-authored by 77 scientists from 37 research institutions in 16 countries. Based on the key focus for each of the papers we have grouped them into five thematic topics: (i) review papers; (ii) papers developing and testing new process descriptions; (iii) papers focusing on how model calibration can improve process descriptions; (iv) papers exploring how the use of multiple model structures can improve model performance and process descriptions; and (v) papers focusing on modelling uncertainties. The grouping of the papers into the five topics should be considered as indicative only, because all papers address more than one of the five themes. The key findings in the papers of this Special Issue are summarized in the following five topic sections.","calibration; evaluation; hydrological modelling; model structure; process description; uncertainty","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-19","","","Water Resources","","",""
"uuid:d9722f27-fe58-4467-9687-c51b420b6b05","http://resolver.tudelft.nl/uuid:d9722f27-fe58-4467-9687-c51b420b6b05","Uncertainties in the Projected Patterns of Wave-Driven Longshore Sediment Transport Along a Non-straight Coastline","Zarifsanayei, Amin Reza (Griffith University); Antolínez, José A. Á. (TU Delft Coastal Engineering); Etemad-Shahidi, Amir (Edith Cowan University; Griffith University); Cartwright, Nick (Griffith University); Strauss, Darrell (Griffith University); Lemos, Gil (University of Lisbon)","","2022","This study quantifies the uncertainties in the projected changes in potential longshore sediment transport (LST) rates along a non-straight coastline. Four main sources of uncertainty, including the choice of emission scenarios, Global Circulation Model-driven offshore wave datasets (GCM-Ws), LST models, and their non-linear interactions were addressed through two ensemble modelling frameworks. The first ensemble consisted of the offshore wave forcing conditions without any bias correction (i.e., wave parameters extracted from eight datasets of GCM-Ws for baseline period 1979–2005, and future period 2081–2100 under two emission scenarios), a hybrid wave transformation method, and eight LST models (i.e., four bulk formulae, four process-based models). The differentiating factor of the second ensemble was the application of bias correction to the GCM-Ws, using a hindcast dataset as the reference. All ensemble members were weighted according to their performance to reproduce the reference LST patterns for the baseline period. Additionally, the total uncertainty of the LST projections was decomposed into the main sources and their interactions using the ANOVA method. Finally, the robustness of the LST projections was checked. Comparison of the projected changes in LST rates obtained from two ensembles indicated that the bias correction could relatively reduce the ranges of the uncertainty in the LST projections. On the annual scale, the contribution of emission scenarios, GCM-Ws, LST models and non-linear interactions to the total uncertainty was about 10–20, 35–50, 5–15, and 30–35%, respectively. Overall, the weighted means of the ensembles reported a decrease in net annual mean LST rates (less than 10% under RCP 4.5, a 10–20% under RCP 8.5). However, no robust projected changes in LST rates on annual and seasonal scales were found, questioning any ultimate decision being made using the means of the projected changes.","uncertainty; longshore sediment transport; ensemble modelling; climate change; projection of wavedriven sediment transport patterns; robustness of projections","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:e32a4af3-8b10-429b-b7eb-3046f0678255","http://resolver.tudelft.nl/uuid:e32a4af3-8b10-429b-b7eb-3046f0678255","Optimization of Charging Strategies for Battery Electric Vehicles under Uncertainty","Huber, Gerhard (University of the Federal Armed Forces Munich); Bogenberger, Klaus (Technische Universität München); van Lint, J.W.C. (TU Delft Transport and Planning)","","2022","The comparably low driving ranges of battery electric vehicles (BEV) cause time-consuming recharging stops if long distances have to be covered. Thus, navigation systems not only have to compute routes leading from the BEV's current position to the destination, but also to plan recharging stops. This type of routing problem is often modeled as a constrained shortest path problem. The constraint ensures that the BEV does not run out of energy. In this paper, a de facto deterministic reformulation of this problem type is suggested, which allows handling uncertainty-particularly the risks resulting from imperfect energy consumption predictions. For this purpose, a certain part of the battery capacity is used as an energy buffer. Different approaches to dynamically optimize the size of this energy buffer in dependency of the expected level of uncertainty are proposed and a corresponding modification of a typical routing algorithm is described. Furthermore, a simulation study is conducted showing that the described framework allows keeping the probability to run out of energy close to zero (for the test settings: < 0.5%) as long as a suitable approach for defining the size of the energy buffer is applied.","Battery electric vehicle; routing; shortest path problem; uncertainty","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.","","2021-04-15","","","Transport and Planning","","",""
"uuid:b0d921fb-cd86-4c82-ba4e-fd56e7e0753c","http://resolver.tudelft.nl/uuid:b0d921fb-cd86-4c82-ba4e-fd56e7e0753c","Policy Analysis of Multi-Actor Systems","Enserink, B. (TU Delft Policy Analysis); Bots, P.W.G. (TU Delft Policy Analysis); van Daalen, C. (TU Delft Policy Analysis); Hermans, L.M. (TU Delft Policy Analysis); Kortmann, Rens (TU Delft Policy Analysis); Koppenjan, Joop (Erasmus Universiteit Rotterdam); Kwakkel, J.H. (TU Delft Policy Analysis); Ruijgh-van der Ploeg, M.P.M. (TU Delft Policy Analysis); Slinger, J (TU Delft Policy Analysis); Thissen, W.A.H. (TU Delft Policy Analysis)","","2022","Policy of Multi-Actor Systems is an introduction into the art of craft of problem exploration and problem structuring. It positions policy analysis as a scientific discipline focused on systems analysis in a multi-actor context to support better informed decision-making. The approach presented in this book is considered to be the cornerstone of the curricula of the Faculty of Technology, Policy and Management of Delft University of Technology and underlies the research on (the governance of) socio-technical systems. Systems thinking applied in a multi-actor environment and its inherent multi-disciplinary character is what makes this work stand out from traditional hard- and soft systems approaches. The core of the book is dedicated to systems analysis, actor- or stakeholder-analysis and discusses methods for dealing with uncertainty. These analytical activities combined lead to a rich problem description and to plans for further research. Due to the stepwise approach this book serves as a basis for any problem analysis both for our bachelor and master students, our alumni worldwide and any interested practitioners.","problem structuring; systems analysis; actor analysis; uncertainty; research proposal; OA-Fund TU Delft","en","book","TU Delft OPEN Publishing","978-94-6236-299-4","","","","","","","","","Policy Analysis","","",""
"uuid:9634fc62-d95f-47f3-b32b-5a6ee93041c1","http://resolver.tudelft.nl/uuid:9634fc62-d95f-47f3-b32b-5a6ee93041c1","A Systematic Literature Review of Predictive Maintenance for Defence Fixed-Wing Aircraft Sustainment and Operations","Scott, Michael J. (Royal Melbourne Institute of Technology University); Verhagen, W.J.C. (Royal Melbourne Institute of Technology University); Bieber, M.T. (TU Delft Air Transport & Operations); Marzocca, Pier (Royal Melbourne Institute of Technology University)","","2022","In recent decades, the increased use of sensor technologies, as well as the increase in digitalisation of aircraft sustainment and operations, have enabled capabilities to detect, diagnose, and predict the health of aircraft structures, systems, and components. Predictive maintenance and closely related concepts, such as prognostics and health management (PHM) have attracted increasing attention from a research perspective, encompassing a growing range of original research papers as well as review papers. When considering the latter, several limitations remain, including a lack of research methodology definition, and a lack of review papers on predictive maintenance which focus on military applications within a defence context. This review paper aims to address these gaps by providing a systematic two-stage review of predictive maintenance focused on a defence domain context, with particular focus on the operations and sustainment of fixed-wing defence aircraft. While defence aircraft share similarities with civil aviation platforms, defence aircraft exhibit significant variation in operations and environment and have different performance objectives and constraints. The review utilises a systematic methodology incorporating bibliometric analysis of the considered domain, as well as text processing and clustering of a set of aligned review papers to position the core topics for subsequent discussion. This discussion highlights state-of-the-art applications and associated success factors in predictive maintenance and decision support, followed by an identification of practical and research challenges. The scope is primarily confined to fixed-wing defence aircraft, including legacy and emerging aircraft platforms. It highlights that challenges in predictive maintenance and PHM for researchers and practitioners alike do not necessarily revolve solely on what can be monitored, but also covers how robust decisions can be made with the quality of data available.","aircraft; decision-making; defence; diagnostics; maintenance; predictive; prognostics; uncertainty","en","journal article","","","","","","","","","","","Air Transport & Operations","","",""
"uuid:0bca9a48-3945-4dc4-a625-15956d29090e","http://resolver.tudelft.nl/uuid:0bca9a48-3945-4dc4-a625-15956d29090e","An Advanced Discrete Fracture Methodology for Fast, Robust, and Accurate Simulation of Energy Production From Complex Fracture Networks","de Hoop, S. (TU Delft Reservoir Engineering); Voskov, D.V. (TU Delft Reservoir Engineering; Stanford University); Bertotti, G. (TU Delft Applied Geology); Barnhoorn, A. (TU Delft Applied Geophysics and Petrophysics)","","2022","Fracture networks are abundant in subsurface applications (e.g., geothermal energy production, CO2 sequestration). Fractured reservoirs often have a very complex structure, making modeling flow and transport in such networks slow and unstable. Consequently, this limits our ability to perform uncertainty quantification and increases development costs and environmental risks. This study provides an advanced methodology for simulation based on Discrete Fracture Model approach. The preprocessing framework results in a fully conformal, uniformly distributed grid for realistic 2D fracture networks at a required level of precision. The simplified geometry and topology of the resulting network are compared with input (i.e., unchanged) data to evaluate the preprocessing influence. The resulting mesh-related parameters, such as volume distributions and orthogonality of control volume connections, are analyzed. Furthermore, changes in fluid-flow response related to preprocessing are evaluated using a high-enthalpy two-phase flow geothermal simulator. The simplified topology directly improves meshing results and, consequently, the accuracy and efficiency of numerical simulation. The main novelty of this work is the introduction of an automatic preprocessing framework allowing us to simplify the fracture network down to required level of complexity and addition of a fracture aperture correction capable of handling heterogeneous aperture distributions, low connectivity fracture networks, and sealing fractures. The graph-based framework is fully open-source and explicitly resolves small-angle intersections within the fracture network. A rigorous analysis of changes in the static and dynamic impact of the preprocessing algorithm demonstrates that explicit fracture representation can be computationally efficient, enabling their use in large-scale uncertainty quantification studies.","complex fracture networks; efficient discrete fracture methodology; geothermal energy; topology; two-phase flow; uncertainty","en","journal article","","","","","","","","","","","Reservoir Engineering","","",""
"uuid:24dd59db-8ae5-4209-80b1-5b3d76985725","http://resolver.tudelft.nl/uuid:24dd59db-8ae5-4209-80b1-5b3d76985725","Dealing With Uncertainty in Early Health Technology Assessment: An Exploration of Methods for Decision Making Under Deep Uncertainty","Scholte, Mirre (Radboud Universiteit Nijmegen); Marchau, V.A.W.J. (Radboud Universiteit Nijmegen); Kwakkel, J.H. (TU Delft Policy Analysis); Klijn, Catharina J.M. (Radboud Universiteit Nijmegen); Rovers, Maroeska M. (Radboud Universiteit Nijmegen); Grutters, Janneke P.C. (Radboud Universiteit Nijmegen)","","2022","Objectives: In early stages, the consequences of innovations are often unknown or deeply uncertain, which complicates early health economic modeling (EHEM). The field of decision making under deep uncertainty uses exploratory modeling (EM) in situations when the system model, input probabilities/distributions, and consequences are unknown or debated. Our aim was to evaluate the use of EM for early evaluation of health technologies. Methods: We applied EM and EHEM to an early evaluation of minimally invasive endoscopy-guided surgery (MIS) for acute intracerebral hemorrhage and compared these models to derive differences, merits, and drawbacks of EM. Results: EHEM and EM differ fundamentally in how uncertainty is handled. Where in EHEM the focus is on the value of technology, while accounting for the uncertainty, EM focuses on the uncertainty. EM aims to find robust strategies, which give relatively good outcomes over a wide range of plausible futures. This was reflected in our case study. EHEM provided cost-effectiveness thresholds for MIS effectiveness, assuming fixed MIS costs. EM showed that a policy with a population in which most patients had severe intracerebral hemorrhage was most robust, regardless of MIS effectiveness, complications, and costs. Conclusions: EHEM and EM were found to complement each other. EM seems most suited in the very early phases of innovation to explore existing uncertainty and many potential strategies. EHEM seems most useful to optimize promising strategies, yet EM methods are complex and might only add value when stakeholders are willing to consider multiple solutions to a problem and adopt flexible research and adoption strategies.","decision making under deep uncertainty; early health technology assessment; health economic modeling; uncertainty","en","journal article","","","","","","","","","","","Policy Analysis","","",""
"uuid:a26fb2f5-8c53-44f3-bbe3-cd6bb8bac626","http://resolver.tudelft.nl/uuid:a26fb2f5-8c53-44f3-bbe3-cd6bb8bac626","Ice Sheet and Climate Processes Driving the Uncertainty in Projections of Future Sea Level Rise: Findings From a Structured Expert Judgement Approach","Bamber, J. L. (University of Bristol; Technische Universität München); Oppenheimer, M. (Princeton University); Kopp, R. E. (Rutgers University); Aspinall, W. P. (University of Bristol; Aspinall and Associates); Cooke, R.M. (TU Delft Applied Probability)","","2022","The ice sheets covering Antarctica and Greenland present the greatest uncertainty in, and largest potential contribution to, future sea level rise. The uncertainty arises from a paucity of suitable observations covering the full range of ice sheet behaviors, incomplete understanding of the influences of diverse processes, and limitations in defining key boundary conditions for the numerical models. To investigate the impact of these uncertainties on ice sheet projections we undertook a structured expert judgement study. Here, we interrogate the findings of that study to identify the dominant drivers of uncertainty in projections and their relative importance as a function of ice sheet and time. We find that for the 21st century, Greenland surface melting, in particular the role of surface albedo effects, and West Antarctic ice dynamics, specifically the role of ice shelf buttressing, dominate the uncertainty. The importance of these effects holds under both a high-end 5°C global warming scenario and another that limits global warming to 2°C. During the 22nd century the dominant drivers of uncertainty shift. Under the 5°C scenario, East Antarctic ice dynamics dominate the uncertainty in projections, driven by the possible role of ice flow instabilities. These dynamic effects only become dominant, however, for a temperature scenario above the Paris Agreement 2°C target and beyond 2100. Our findings identify key processes and factors that need to be addressed in future modeling and observational studies in order to reduce uncertainties in ice sheet projections.","expert judgement; ice sheets; sea level rise; uncertainty","en","journal article","","","","","","","","","","","Applied Probability","","",""
"uuid:c75f864b-814f-4f8d-b749-0b503906af15","http://resolver.tudelft.nl/uuid:c75f864b-814f-4f8d-b749-0b503906af15","Quantifying the Uncertainty of Short-Term Vegetation Anomalies Detection Using Eo-Based Coarse-Resolution Vegetation Products","Zhou, J. (TU Delft Optical and Laser Remote Sensing; Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan); Liu, Xuan (Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan); Xiong, Xuqian (Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan); Jia, Li (Chinese Academy of Sciences); Lu, Jing (Chinese Academy of Sciences); Cui, Yilin (Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan)","","2022","Satellite-based Earth Observation systems archived a variety of vegetation products during the last 50 years, which can reveal regional to global ecosystem dynamics across diverse spatiotemporal scales. The anomaly metrics such as Vegetation Condition Index (VCI) defined by comparing the current vegetation growth condition to historical average status based on long-term EO-based vegetation products were widely used to delineate abnormal vegetation variation exerted by either climatic or anthropogenic factors (e.g., droughts, wildfires). However, currently available long-term vegetation products may differ from each other in terms of sensors (observational platform or spectral bands), bio-physical definitions (e.g., NDVI, EVI, LAI, and VOD), spatiotemporal resolution, as well as the time-spans, which results in inconsistency across these vegetation products. Taking the VCI as an example, this study evaluated the uncertainty of vegetation anomalies detected based on different vegetation products over the middle reach of the Yangtze River by explicitly considering the effect of sensors, biophysical definitions, and time-spans. The preliminary results showed that VCI derived from NDVI products from different sensors (AVHRR vs. MODIS) induced significant inconsistent anomalies over most landscapes. The differences resulting from products with different biophysical definitions (NDVI vs. EVI, LAI, and VOD) are much lower than those from different sensors but still significant over specific areas. As for the time-spans, the 20-year NDVI based VCI presented a considerable reduction in variance over the study area on average compared to VCI calculated based on 5-year NDVI. In summary, caution should be taken when applying EO-based vegetation products for vegetation anomalies mapping, especially for quantitative assessment.","EO-based vegetation products; uncertainty; vegetation anomalies; Vegetation Condition Index","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Optical and Laser Remote Sensing","","",""
"uuid:66a6b145-9370-49ec-864f-95c1ff470563","http://resolver.tudelft.nl/uuid:66a6b145-9370-49ec-864f-95c1ff470563","OC6 Phase Ia: CFD Simulations of the Free-Decay Motion of the DeepCwind Semisubmersible","Wang, Lu (National Renewable Energy Laboratory); Robertson, Amy (National Renewable Energy Laboratory); Jonkman, Jason (National Renewable Energy Laboratory); Kim, Jang (Front Energies); Shen, Zhi‐Rong (Front Energies); Koop, Arjen (Maritime Research Institute Netherlands (MARIN)); Chandramouli, P. (TU Delft Wind Energy); Viré, A.C. (TU Delft Wind Energy); Ramesh Reddy, L. (TU Delft Wind Energy)","","2022","Currently, the design of floating offshore wind systems is primarily based on mid-fidelity models with empirical drag forces. The tuning of the model coefficients requires data from either experiments or high-fidelity simulations. As part of the OC6 (Offshore Code Comparison Collaboration, Continued, with Correlation, and unCertainty (OC6) is a project under the International Energy Agency Wind Task 30 framework) project, the present investigation explores the latter option. A verification and validation study of computational fluid dynamics (CFD) models of the DeepCwind semisubmersible undergoing free-decay motion is performed. Several institutions provided CFD results for validation against the OC6 experimental campaign. The objective is to evaluate whether the CFD setups of the participants can provide valid estimates of the hydrodynamic damping coefficients needed by mid-fidelity models. The linear and quadratic damping coefficients and the equivalent damping ratio are chosen as metrics for validation. Large numerical uncertainties are estimated for the linear and quadratic damping coefficients; however, the equivalent damping ratios are more consistently predicted with lower uncertainty. Some difference is observed between the experimental and CFD surge-decay motion, which is caused by mechanical damping not considered in the simulations that likely originated from the mooring setup, including a Coulomb-friction-type force. Overall, the simulations and the experiment show reasonable agreement, thus demonstrating the feasibility of using CFD simulations to tune mid-fidelity models.","CFD; validation; free decay; offshore wind; semisubmersible; uncertainty; OC6; IEA; Free decay; Validation; Uncertainty; Semisubmersible; Offshore wind","en","journal article","","","","","","","","","","","Wind Energy","","",""
"uuid:0fd5201c-09cd-46e1-899c-47c0d9ad1f6b","http://resolver.tudelft.nl/uuid:0fd5201c-09cd-46e1-899c-47c0d9ad1f6b","Best-Worst Method: Inconsistency, Uncertainty, Consensus, and Range Sensitivity","Liang, F. (TU Delft Transport and Logistics)","Rezaei, J. (promotor); Brunelli, Matteo (promotor); Delft University of Technology (degree granting institution)","2021","It is our choices that make us who we are. To lead a better life, we have to make better decisions. Nowadays, decisions are increasingly made in complex contexts, in a host of different application domains. Because of that, we need more reliable decision analysis methodologies to improve our decisions. The ability to deal with multi-dimensionality is one of the critical requirements of the decision analysis methods that help us make better decisions. Multi-Criteria Decision-Making (MCDM) is one of the most popular approaches when it comes to formulating and solving decision-making problems, best-known for its ability to handle problems where a multitude of, often conflicting, criteria arise. As one of the latest MCDM methods, the Best-Worst Method (BWM) has been studied substantially and applied increasingly to various fields since its introduction, thanks to its simplicity, flexibility and general applicability. Despite its popularity, some significant issues of BWM have not yet been systematically investigated in existing literature, including: (i) the inconsistency in the preferences provided by Decision-Makers (DMs), (ii) the uncertain information embedded in the DMs’ judgements, (iii) problems in reaching a consensus in group decision-making, and (iv) the range sensitivity in an MCDM problem that is not taken into account in BWM. The main objective of this thesis is to develop an approach to measure, check and improve inconsistency, to develop an approach to incorporate judgments uncertainty, to develop a method to reach consensus and to incorporate range sensitivity in the BWM.","Best-Worst Method; inconsistency; uncertainty; consensus; range sensitivity","en","doctoral thesis","","978-94-6366-484-4","","","","","","","","","Transport and Logistics","","",""
"uuid:745928c2-1e5d-4df7-b9c0-0c7956001dfe","http://resolver.tudelft.nl/uuid:745928c2-1e5d-4df7-b9c0-0c7956001dfe","Uncertainties based queries for Interactive policy learning with evaluations and corrections","Celemin, Carlos (TU Delft Learning & Autonomous Control); Kober, J. (TU Delft Learning & Autonomous Control)","Hammal, Zakia (editor); Busso, Carlos (editor); Pelachaud, Catherine (editor); Oviatt, Sharon (editor); Salah, Albert Ali (editor); Zhao, Guoying (editor)","2021","","ambiguities; corrective feedback; evaluative feedback; Interactive Learning; uncertainty","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.","","2022-06-17","","","Learning & Autonomous Control","","",""
"uuid:9f0918e0-cc1f-408f-b011-be5d05858683","http://resolver.tudelft.nl/uuid:9f0918e0-cc1f-408f-b011-be5d05858683","Influence of uncertainty on performance of opportunistic maintenance strategy for offshore wind farms","Li, M. (TU Delft Transport Engineering and Logistics); Jiang, X. (TU Delft Transport Engineering and Logistics); Carroll, James (University of Strathclyde); Negenborn, R.R. (TU Delft Transport Engineering and Logistics)","","2021","The increasing capacity of offshore wind energy around the world brings challenges in Operation and Maintenance (O&M) management. Over the past years, many studies have focused on developing sound maintenance strategies in order to minimize maintenance cost or maximize availability. One of the promising maintenance strategies is opportunistic maintenance due to its potential to combine maintenance activities and save maintenance efforts. In these models, a common assumption is made that input parameters are deterministic and maintenance decisions are made based on these assumed deterministic input parameters. However, offshore wind farm maintenance in the practical world is a complicated task where multiple types of uncertainty exist. These uncertainties may affect evaluation or output of the maintenance model, making maintenance decisions sub-optimal or even inappropriate. In this paper, a probabilistic simulation-based approach integrating an uncertainty module and a simulation module is proposed to study the influence of the uncertainties on maintenance performance. We identify the primary input parameters which should be considered as uncertainty but are simplified to be deterministic values in offshore wind energy maintenance models. These deterministic parameters are modelled as stochastic values in the uncertainty module to generate uncertainty scenarios. The simulation module for opportunistic maintenance is developed to quantity the expected maintenance cost and lost production. The most influential uncertainties are identified. Valuable information and suggestions are provided to offshore wind farm owners for future decision-making and project management.","maintenance strategy; uncertainty; offshore wind energy; operation and maintenance","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.","","2022-08-15","","","Transport Engineering and Logistics","","",""
"uuid:70cf7b7b-b4d6-4a72-aec8-365af8c9edba","http://resolver.tudelft.nl/uuid:70cf7b7b-b4d6-4a72-aec8-365af8c9edba","Higher Education and Wicked Problems: Students Engaging with Complexity and Uncertainty in Sustainability Transitions","Fenten, Jan (Universiteit Leiden); Bohm, N.L. (TU Delft Urban Development Management); Van den Berg, Bas (De Haagse Hogeschool)","","2021","The challenges we collectively face, such as climate change, are characterized by more complexity, interdependence, and dynamism than is common for educational practice. This presents a challenge for (university) education. These sustainability transition challenges are often described as wicked or VUCA (Volatile, Uncertain, Complex, and Ambiguous) problems. In response, educational innovations that are inspired by ecology, such as living labs are starting to emerge, but little is known about how students engage within and with these more ecologically-inspired forms of education. This work is an exploratory study into how students navigate VUCA learning environments linked to tackling sustainability transition challenges, with a focus on the positive qualities of these experiences. This is done through interpretative phenomenological analysis (IPA) of seven students (using semi- structured interviews) of the MSc Metropolitan Analysis, Design and Engineering program, a joint degree from Wageningen University and Delft University of Technology in the Netherlands. The main findings, which are both psychological and educational, of this exploration include openness to new experiences (1), flexibility (2), a process appreciation of learning (3), a desire to create a positive impact on one’s direct biophysical environment and society (4). In addition, we discuss the potential limitations of the malleability of these different qualities and propose future avenues for research into ecological learning for universities. This work closes by highlighting recommendations for educators to consider when designing or engaging in ecological forms of higher education that connect to sustainability transitions.","VUCA; Sustainability transitions; Ecological learning; uncertainty; complexity; Higher Education; Wicked problems","en","conference paper","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-08-07","","","Urban Development Management","","",""
"uuid:1466625e-5b5d-46f0-a02c-386a1ad7a7fc","http://resolver.tudelft.nl/uuid:1466625e-5b5d-46f0-a02c-386a1ad7a7fc","Optimized Expansion Strategy for a Hydrogen Pipe Network in the Port of Rotterdam with Compound Real Options Analysis","van den Boomen, M. (TU Delft Integral Design & Management; Rotterdam University of Applied Sciences); Van der Meulen, Sjoerd (Rotterdam University of Applied Sciences; HAN University of Applied Sciences); Van Ekris, Jonathan (Rotterdam University of Applied Sciences); Spanjers, Roel (Rotterdam University of Applied Sciences); Ten Voorde, Olle (Rotterdam University of Applied Sciences); Mulder, Janwin (Rotterdam University of Applied Sciences); Blommaart, Peter (Rotterdam University of Applied Sciences)","","2021","br/>The port of Rotterdam is the largest seaport in Europe. To maintain its position, the harbor will have to anticipate global transitions such as transferring to sustainable energy. Hydrogen is seen as a promising energy carrier; however, future demand is uncertain. The current research investigates decision making under uncertainty and values flexibility. Compound real options analysis is applied to optimize the time-variant expansion strategies for a hydrogen pipe network. The trade-off between early investments and missed revenues when not investing in time determines the optimized expansion strategy. Moreover, the real options approach also provides the levelized unit price for hydrogen distribution, to cover the life cycle costs of the optimal expansion strategy. Finally, this real options approach offers flexibility to a decision maker as it allows for enhancing future decisions. The academic contribution of this research is a distinct perspective on a compound real options approach where the optimal strategic path is the key result of interest. This in contrast to other real options applications in the literature which focus on option value, exchange with limiting the options or do not visualize a strategic path. Moreover, this research demonstrates how stepwise expansion and decision making under uncertainty facilitate transitions such as the transition toward clean energy.","real options analysis; expansion; compound options; adaptive decision making; uncertainty","en","journal article","","","","","","","","","","","Integral Design & Management","","",""
"uuid:3cef9da8-d432-4d6a-8805-4c094440bd56","http://resolver.tudelft.nl/uuid:3cef9da8-d432-4d6a-8805-4c094440bd56","Replacement optimisation for public infrastructure assets: Quantitative optimisation modelling taking typical public infrastructure related features into account","van den Boomen, M. (TU Delft Integral Design & Management)","Bakker, H.L.M. (promotor); Kapelan, Z. (promotor); Delft University of Technology (degree granting institution)","2020","Ageing infrastructures and shortage of financing induce the need for optimising public infrastructure replacements. From an economic perspective, classical net present value comparison is traditionally the method of choice to decide on investments and replacements. The current research observes that typical infrastructure related features make the classical net present value comparison less suitable in its application for optimising infrastructure replacements. Especially the low discount rate of public sector organisations, price increases and price uncertainty contribute to this phenomenon in which the application of classical net present value comparison leads to suboptimal timing and costs. This observation led to the development of six dedicated replacement optimisation models for common types of infrastructure replacement challenges. A decision support guideline is provided to assist in selecting an appropriate model based on the sequence of intervention strategies, the development of forecasted cash flows and whether uncertainty is involved. The quantitative replacement optimisation models function as blueprints for similar challenges and support a wider decision-making context.","replacement; optimisation; public infrastructure; reliability; real options; uncertainty; Markov decision process","en","doctoral thesis","","978‐94‐028‐1965‐6","","","","","","2020-03-25","","","Integral Design & Management","","",""
"uuid:b13eba55-3181-4d8c-8312-0982ba390e48","http://resolver.tudelft.nl/uuid:b13eba55-3181-4d8c-8312-0982ba390e48","Untangling decision tree and real options analyses: a public infrastructure case study dealing with political decisions, structural integrity and price uncertainty","van den Boomen, M. (TU Delft Integral Design & Management); Spaan, M.T.J. (TU Delft Algorithmics); Schoenmaker, R. (TU Delft Integral Design & Management); Wolfert, A.R.M. (TU Delft Integral Design & Management; TU Delft Materials and Environment)","","2019","Managerial flexibility in infrastructure investment and replacement decisions adds value. Real options analysis (ROA) captures this value under uncertain market prices. The concept of ROA is that future unfavourable payoffs can be deferred as soon as more information about market prices becomes available. The popularity of ROA is seen in a growing number of case studies on real assets. Despite its increasing popularity, ROA has not gained a foothold in public infrastructure decision making. One of the difficulties in the application of ROA is the required estimation of market variables. To avoid this, a simplified but not correct version of ROA is easily applied, referred to as a Decision Tree Approach (DTA) to ROA. Another difficulty is that infrastructure assets are subject to other types of uncertainties, defined here as asset uncertainties. This study investigates the value of managerial flexibility in a public infrastructure replacement decision. The uncertainty drivers are the strength of a bridge, political decisions regarding traffic flow and the price development of construction costs. Three valuation approaches are compared: DTA, ROA and the DT approach to ROA. Although it is complex, ROA certainly adds value in public infrastructure decision making when market price uncertainty is prevalent. However, in the absence of reasonable estimates of market variables, the DT approach to ROA is the best alternative. In the absence of market price uncertainties, ROA should be avoided DTA is to be preferred.","decision analysis; infrastructure planning; Real options; replacement; uncertainty","en","journal article","","","","","","","","","","","Integral Design & Management","","",""
"uuid:fab05adb-73b3-4261-8102-f15c943ef27a","http://resolver.tudelft.nl/uuid:fab05adb-73b3-4261-8102-f15c943ef27a","An Effective Couple Method for Reliability-Based Multi-Objective Optimization of Truss Structures with Static and Dynamic Constraints","Vo-Duy, T. (Ton Duc Thang University); Duong-Gia, D. (Ton Duc Thang University); Ho-Huu, V. (TU Delft Air Transport & Operations); Nguyen-Thoi, T. (Ton Duc Thang University)","","2019","This paper proposes an effective couple method for solving reliability-based multi-objective optimization problems of truss structures with static and dynamic constraints. The proposed coupling method integrates a single-loop deterministic method (SLDM) into the nondominated sorting genetic algorithm II (NSGA-II) algorithm to give the so-called SLDM-NSGA-II. Thanks to the advantage of SLDM, the probabilistic constraints are treated as approximating deterministic constraints. And therefore the reliability-based multi-objective optimization problems can be transformed into the deterministic multi-objective optimization problems of which the computational cost is reduced significantly. In these reliability-based multi-objective optimization problems, the conflicting objective functions are to minimize the weight and the displacements of the truss. The design variables are cross-section areas of the bars and contraints include static and dynamic constraints. For reliability analysis, the effect of uncertainty of parameters such as force, added mass in the nodes, material properties and cross-section areas of the bars are taken into account. The effectiveness and reliability of the proposed method are demonstrated through three benchmark-type truss structures including a 10-bar planar truss, a 72-bar spatial truss and a 200-bar planar truss. Moreover, the influence of parameters on the reliability-based Pareto optimal fronts is also carried out.","Multi-objective optimization; non-dominated sorting genetic algorithm II (NSGA-II); reliability-based multi-objective optimization; single-loop algorithm; static and dynamic constraints; uncertainty","en","journal article","","","","","","","","2020-05-01","","","Air Transport & Operations","","",""
"uuid:8c869465-d0ad-489a-aa38-d9d08a209ff5","http://resolver.tudelft.nl/uuid:8c869465-d0ad-489a-aa38-d9d08a209ff5","Accounting for the uncertain effects of hydraulic interactions in optimising embankments heights: Proof of principle for the IJssel River","Ciullo, A. (TU Delft Policy Analysis; Deltares); de Bruijn, Karin M. (Deltares); Kwakkel, J.H. (TU Delft Policy Analysis); Klijn, F. (TU Delft Policy Analysis; Deltares)","","2019","Most alluvial plains in the world are protected by flood defences, for example, embankments, whose primary aim is to reduce the probability of flooding of the protected areas. At the same time, however, the presence of embankments at one area influences hydraulic conditions of downstream areas located on the same river. These hydraulic interactions are often neglected in current flood risk management. The aim of this study is to explicitly acknowledge hydraulic interactions and investigate their impact on establishing optimal embankment heights along a stretch of the IJssel River. We find that the current approach leads to a single solution, while taking into account hydraulic interactions substantially expands the number of promising solutions. Furthermore, under a reference scenario, the current approach is in fact suboptimal with respect to both downstream locations and the system as a whole. Under uncertainty, it performs adequately from a system viewpoint, but poorly for individual locations, mostly due to risk overestimation downstream. Overall, the current approach proves to be too short-sighted, because spatial trade-offs among locations are neglected and alternative solutions remain hidden. Acknowledging the effect of hydraulic interactions provides policy makers with a broader and more comprehensive spectrum of flood risk management strategies.","flood risk; hydraulic interactions; many-objective optimization; robust decision making; system approach; uncertainty","en","journal article","","","","","","","","","","","Policy Analysis","","",""
"uuid:a2115853-fdb7-4ad9-9435-99e470d0fd9c","http://resolver.tudelft.nl/uuid:a2115853-fdb7-4ad9-9435-99e470d0fd9c","Dynamic and Robust Timetable Rescheduling for Uncertain Railway Disruptions","Zhu, Y. (TU Delft Transport and Planning); Goverde, R.M.P. (TU Delft Transport and Planning)","Peterson, Anders (editor); Joborn, Martin (editor); Bohlin, Markus (editor)","2019","Unexpected disruptions occur frequently in railway systems, during which many train services cannot run as scheduled. This paper deals with timetable rescheduling during such disruptions, particularly in the case where all tracks between two stations are blocked for a few hours. In practice, the disruption length is uncertain, and a disruption may become shorter or longer than predicted. Thus, it is necessary to take the uncertainty of the disruption duration into account. This paper formulates the robust timetable rescheduling as a rolling horizon two-stage stochastic programming problem in deterministic equivalent form. The random disruption duration is assumed to have a finite number of possible realizations, called scenarios, with given probabilities. Every time a prediction about the range of the disruption end time is updated, new scenarios are defined, and the model computes the optimal rescheduling solution for an extended control horizon, which is robust to all these scenarios. Based on the model, uncertain disruptions can be handled with robust solutions in a dynamic environment. The stochastic method was tested on a part of the Dutch railways, and compared to a deterministic rolling-horizon method. The results showed that compared to the deterministic method, the stochastic method is more likely to generate better rescheduling solutions for uncertain disruptions by less train cancellations and/or delays, while the solution robustness can be affected by the predicted range regarding the disruption end time.","uncertainty; disruption management; rescheduling; stochastic programming; rolling horizon","en","conference paper","","","","","","","","","","","Transport and Planning","","",""
"uuid:23d0fc8f-bdd0-41e0-9dd7-3f7f896d0d5c","http://resolver.tudelft.nl/uuid:23d0fc8f-bdd0-41e0-9dd7-3f7f896d0d5c","Dynamic Planning for Flexible Port Infrastructure after Panama Canal Expansion: A Real Case Study","Reyes, O. Soto (Panama Canal Authority); Taneja, P. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Pielage, B. A. (Witteveen+Bos); Van Schuylenburg, M. (IHE Delft Institute for Water Education)","Jain, Pooja (editor); Stahlman, William S. (editor)","2019","This paper presents a study carried out to first assess the impact of the Panama Canal expansion (PCE) on selected Caribbean ports, and thereafter, to examine how the ports can adapt in order to seize new opportunities created by the expansion. An applied case of long-term dynamic planning and flexibility in engineering design is presented for a new port terminal in Barranquilla, Colombia. Furthermore, this paper presents the results of a stochastic method for quantifying opportunities from containerized traffic using dynamic forecasting, real options analysis, and Monte Carlo simulation, within the framework and spirit of adaptive port planning under uncertainty.","adaptive; Dynamic Forecasting; Dynamic planning; flexibility; Monte Carlo Simulation; opportunities; Real Options; uncertainty","en","conference paper","American Society of Civil Engineers (ASCE)","","","","","Accepted Author Manuscript","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:7f9d5eaf-87dc-4e59-b599-69783594662c","http://resolver.tudelft.nl/uuid:7f9d5eaf-87dc-4e59-b599-69783594662c","Uncertainty Tracking and Geotechnical Reliability Updating Using Bayesian Networks","Duvvuru Mohan, V.K. (TU Delft Geo-engineering); Vardon, P.J. (TU Delft Geo-engineering); Hicks, M.A. (TU Delft Geo-engineering); van Gelder, P.H.A.J.M. (TU Delft Safety and Security Science)","Ching, Jianye (editor); Li, Dian-Qing (editor); Zhang, Jie (editor)","2019","Bayesian networks are proposed as a tool to integrate reliability and influential variables relating to the slope stability of an idealized embankment. The site investigation (extent) and slope geometry, as well as the material properties and their spatial variability, are considered within a Bayesian network. The random finite element method (RFEM) is used to quantify the slope reliability and demonstrate the overall methodology. Prior probabilities of geometry, material parameters and their heterogeneity are obtained from ‘initial’ site investigation data. Probabilistic distributions of slope performance (factor of safety) are obtained by Bayesian inference in the network to investigate the impact of additional site investigation. The amount of additional site investigation required to increase the geotechnical reliability is assessed. This work illustrates the applicability of Bayesian networks as an effective reliability and uncertainty assessment tool that can aid decision making for site investigation and during maintenance, where new observations can be readily integrated to obtain updated reliability estimates.","Bayesian network; geotechnical reliability; random fields; slope reliability; spatial variability; uncertainty","en","conference paper","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-06-13","","","Geo-engineering","","",""
"uuid:9be9c07f-0399-49f7-b6bf-99d725ad7e25","http://resolver.tudelft.nl/uuid:9be9c07f-0399-49f7-b6bf-99d725ad7e25","Comparative analysis of nonparametric change-point detectors commonly used in hydrology","Zhou, C. (TU Delft Water Resources); van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (TU Delft Water Resources); Hrachowitz, M. (TU Delft Water Resources)","","2019","Several commonly-used nonparametric change-point detection methods are analysed in terms of power, ability and accuracy of the estimated change-point location. The analysis is performed with synthetic data for different sample sizes, two types of change and different magnitudes of change. The methods studied are the Pettitt method, a method based on the Cramér von Mises (CvM) two-sample test statistic and a variant of the CUSUM method. The methods differ considerably in behaviour. For all methods the spread of estimated change-point location increases significantly for points near one of the ends of the sample. Series of annual maximum runoff for four stations on the Yangtze River in China are used to examine the performance of the methods on real data. It was found that the CvM-based test gave the best results, but all three methods suffer from bias and low detection rates for change points near the ends of the series.","ability; change-point detection; Cramér von Mises test; CUSUM test; Pettitt test; power; uncertainty","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:953b6795-560d-470e-809e-0dda843ecc68","http://resolver.tudelft.nl/uuid:953b6795-560d-470e-809e-0dda843ecc68","From Deterministic to Generative: Multimodal Stochastic RNNs for Video Captioning","Song, Jingkuan (University of Electronic Science and Technology of China); Guo, Yuyu (University of Electronic Science and Technology of China); Gao, Lianli (University of Electronic Science and Technology of China); Li, Xuelong (Chinese Academy of Sciences); Hanjalic, A. (TU Delft Intelligent Systems); Shen, Heng Tao (University of Electronic Science and Technology of China)","","2018","Video captioning, in essential, is a complex natural process, which is affected by various uncertainties stemming from video content, subjective judgment, and so on. In this paper, we build on the recent progress in using encoder-decoder framework for video captioning and address what we find to be a critical deficiency of the existing methods that most of the decoders propagate deterministic hidden states. Such complex uncertainty cannot be modeled efficiently by the deterministic models. In this paper, we propose a generative approach, referred to as multimodal stochastic recurrent neural networks (MS-RNNs), which models the uncertainty observed in the data using latent stochastic variables. Therefore, MS-RNN can improve the performance of video captioning and generate multiple sentences to describe a video considering different random factors. Specifically, a multimodal long short-term memory (LSTM) is first proposed to interact with both visual and textual features to capture a high-level representation. Then, a backward stochastic LSTM is proposed to support uncertainty propagation by introducing latent variables. Experimental results on the challenging data sets, microsoft video description and microsoft research video-to-text, show that our proposed MS-RNN approach outperforms the state-of-the-art video captioning benchmarks.","Recurrent neural network (RNN); uncertainty; video captioning.","en","journal article","","","","","","Accepted Author Manuscript","","","","Intelligent Systems","","","",""
"uuid:19dc6b8e-dee4-44af-a598-24a4dfbeb83e","http://resolver.tudelft.nl/uuid:19dc6b8e-dee4-44af-a598-24a4dfbeb83e","Discussion of “Perceptual models of uncertainty for socio-hydrological systems: a flood risk change example” * ","Ertsen, M.W. (TU Delft Water Resources)","","2018","Dealing with uncertainty is key in socio-hydrological analysis. As such, thinking through what uncertainties mean for whom and when is key. This discussion contribution introduces three issues related to defining uncertainties. The first issue deals with the problem of defining uncertainty as a given external reality. The second issue deals with who decides about relevant uncertainties. The third issue deals with the issue whether coupled human-hydrological systems can be seen as existing on their own. Finally, the text provides two examples of hydrological research that try to be explicit about our dealing with multiple (interpretations of) realities.","hydrological models; socio-hydrology; uncertainty","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-06-03","","","Water Resources","","",""
"uuid:1bae2e58-0136-4a04-96b1-b07e9e364a0f","http://resolver.tudelft.nl/uuid:1bae2e58-0136-4a04-96b1-b07e9e364a0f","From integration mainstreaming to convivial disintegration: how superdiversity shows the pitfalls of (mainstreaming) immigrant integration","Meissner, F.V.M. (TU Delft OLD Urban Renewal and Housing)","","2018","The emergent literature on mainstreaming immigrant integration frequently references the term superdiversity. The diversification of migration is put forward as one rational for implementing measures to support immigrant integration across policy fields and across levels of policy making. In this paper I reflect on those assertions and argue that contrarily using superdiversity is not an argument in favour of mainstreaming immigrant integration, but that instead a superdiversity lens is uniquely placed to critically examine whether the goal of mainstreaming should be integration at all. To move this argument forward I propose more concertedly thinking about the merits of better understanding convivial disintegration as a more adequate starting point for thinking through the social and economic implications of international migration and how to address them through policy interventions.","convivial disintegration; complexity; uncertainty; superdiversity; integration policy,; mainstreaming","en","working paper","Max Planck for the Study of Religious and Ethnic Diversity","","","","","","","","","","OLD Urban Renewal and Housing","","",""
"uuid:9428475f-8360-425b-86d1-ad684d03421c","http://resolver.tudelft.nl/uuid:9428475f-8360-425b-86d1-ad684d03421c","Towards sustainable infrastructure with planned adaptation","Taneja, P. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)","","2018","In the present turbulent environment, adaptability and robustness belong under the overarching definition of sustainability. Sustainable infrastructures should not only achieve economic, environmental, and social objectives, but should be robust and adaptable under uncertainty. This paper examines the current guidelines for port development and concludes that a comprehensive planning approach that systematically accounts for uncertainty during planning, to result in a sustainable plan, is missing. It proposes an approach for port planning based on planned adaptation. Case studies illustrating how planned adaptation can effectively help to deal with short- and long term vulnerabilities, and seize opportunities to come up with sustainable plans that are able to achieve economic, environmental, and social objectives for a long-term uncertain future, are presented.","Adaptive port planning; planned adaptation; flexibility; infrastructure planning; sustainable infrastructure; maritime port planning; uncertainty","en","conference paper","Pianc","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:82981ce2-e734-440f-91e6-061e568125dc","http://resolver.tudelft.nl/uuid:82981ce2-e734-440f-91e6-061e568125dc","What lies beneath: Bounded manageability in complex underground infrastructure projects","Leijten, M. (TU Delft Organisation & Governance)","de Bruijn, J.A. (promotor); Veeneman, Wijnand (copromotor); Delft University of Technology (degree granting institution)","2017","Complex underground infrastructure construction projects tend to develop in a state of “bounded manageability”. Various types of uncertainties are inherent to these projects and put the project manager in front of serious challenges, risking budget overruns, delays and sometimes even technical failure. Managing such a project is a matter of considering the options to keep ambitions and means in balance, without losing control. In practice this means that project managers, when confronted with these uncertainties in their projects, have to make trade-offs that have strong “double-bind” characteristics. With every advantage come serious downsides. This disables them to make optimal decisions. Moreover, a chosen path pre-defines conditions for later trade-offs that were often not considered explicitly when choosing this path. This research provides a new framework for understanding uncertainty in the management of projects. It maps out the typical manageability dilemmas that evolve in complex underground infrastructure projects and comes with suggestions to improve this manageability.","infrastructure; project management; uncertainty","en","doctoral thesis","","978-94-6233-694-0","","","","","","","","","Organisation & Governance","","",""
"uuid:1dbabb9d-a825-4dc0-9927-d1bf8d03ae93","http://resolver.tudelft.nl/uuid:1dbabb9d-a825-4dc0-9927-d1bf8d03ae93","Strategic Modeling of Global Container Transport Networks: Exploring the future of port-hinterland and maritime container transport networks","Halim, R.A. (TU Delft Transport and Logistics)","Tavasszy, Lorant (promotor); Kwakkel, J.H. (copromotor); Delft University of Technology (degree granting institution)","2017","Uncertainties in future global trade flows due to changes in trade agreements, transport technologies or sustainability policies, will affect the patterns of global freight transport and, as a consequence, also affect the demand for major freight transport infrastructures such as ports and hinterland networks. Policy makers face the challenge of making robust policies and investments that sustain and promote economic development amidst the various uncertainties. This thesis proposes a set of empirically grounded quantitative models of global freight transport that can support strategic decision making about investments in freight transport infrastructures. We specify, estimate and validate these models for both maritime and hinterland transport, and apply them in comprehensive analyses of the EU’s and the global container transport networks.","global container transport; freight transport modeling; port-hinterland transport networks; global maritime networks; uncertainty; scenario discovery","en","doctoral thesis","TRAIL Research School","978-90-5584-220-9","","","","TRAIL Thesis Series no. T2017/1, the Netherlands Research School TRAIL","","","","","Transport and Logistics","","",""
"uuid:211e9dc4-7332-426a-aa11-9f6749423c9b","http://resolver.tudelft.nl/uuid:211e9dc4-7332-426a-aa11-9f6749423c9b","The influence of the length of the calibration period and observation frequency on predictive uncertainty in time series modeling of groundwater dynamics","van der Spek, J.E. (TU Delft Water Resources); Bakker, M. (TU Delft Structural Integrity & Composites)","","2017","The influence of the length of the calibration period and observation frequency on the predictive uncertainty in time series modeling of groundwater dynamics is investigated. Studied series are from deltaic regions with predominantly shallow groundwater tables in a temperate maritime climate where heads vary due to precipitation and evaporation. Response times vary over a wide range from ∼60 to ∼1200 days. A Transfer Function-Noise model is calibrated with the Markov Chain Monte Carlo method to both synthetic series and measured series of heads. The model fit and uncertainty are evaluated for various calibration periods and observation frequencies. It is often assumed that the required length of the calibration period is related to the response time of the system. In this study, no strong relationship was observed. Results indicate, however, that the required length of the calibration period is related to the decay time of the noise. Furthermore, the length of the calibration period was much more important than the total number of observations. For the measured series, the credible intervals could commonly be reduced to ∼10% of the measured head range and the prediction intervals to ∼50% of the measured head range with calibration periods of 20 years with approximately two observations per month.","calibration period; observation frequency; time series analysis; uncertainty","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:424c4f19-4bd2-48cd-9221-b6e3e8426636","http://resolver.tudelft.nl/uuid:424c4f19-4bd2-48cd-9221-b6e3e8426636","Uncertainty assessment in coastal morphology prediction with a bayesian network","Kroon, J. (TU Delft Coastal Engineering; Svašek Hydraulics); de Schipper, M.A. (TU Delft Coastal Engineering; Shore Monitoring & Research); den Heijer, C. (TU Delft Management Support; TU Delft Coastal Engineering; Deltares); Aarninkhof, S.G.J. (TU Delft Coastal Engineering); van Gelder, P.H.A.J.M. (TU Delft Safety and Security Science)","Aagaard, T. (editor); Deigaard, R. (editor); Fuhrman, D. (editor)","2017","In the present time of sea-level rise and climate change a global shift has occurred toward sandy coastal protection measures and Building with Nature. These type of protection measures impose extra uncertainty on the instantaneous state of the coastal system over time for which present deterministic forecasting techniques are not capable of providing necessary information on uncertainties and hence could display a false sense of accuracy and skill. At present in long term morphological modeling a full systemic approach for uncertainty assessment has not yet been applied. This paper investigates the use of a Bayesian Network as a tool for uncertainty assessment in decadal scale morphological modeling for the evolution of a mega nourishment at the Dutch North-Holland coast, the Hondsbossche Dunes (HBD). The Bayesian Network is trained with an existing set of model data and field data of one year bed development. The Bayesian Network successfully transfers the bandwidth in input variables, model uncertainty and calibration uncertainty to an uncertainty bandwidth around the output parameter of choice.","Bayesian Network; uncertainty; morphodynamics; numerical modelling; Building with Nature","en","conference paper","","","","","","","","","","","Coastal Engineering","","",""
"uuid:340af6c1-5be2-4e86-ac3a-833292f0d3e9","http://resolver.tudelft.nl/uuid:340af6c1-5be2-4e86-ac3a-833292f0d3e9","Design-led innovation and sensemaking: Opportunities to connect","Price, R.A. (TU Delft Marketing and Consumer Research); Wrigley, Cara (University of Sydney); Matthews, Judy (Queensland University of Technology)","Bohemia, E. (editor); de Bont, C. (editor); Svengren Holm, L. (editor)","2017","Design-led innovation (DLI) is a framework with particular focus on developing design capability. Implementation of DLI has been observed to positively influence firm innovation performance. As the framework is of relative infancy, there is opportunity to learn from and integrate methods and practice from other fields to strengthen the implementation of DLI. Therefore, the aim of this paper is to make explicit, the similarities DLI shares with sensemaking as in order to provider clearer approaches to managing the design process. An action research design is applied for 14 months within a major Australian Airport Corporation (AAC) to implement DLI. Qualitative data is collected and analysed, with the findings showing there are implicit similarities between the practice of DLI and mandates of sensemaking. The paper contributes opportunities to strengthen DLI by incorporating mandates of sensemaking consciously to enrich interpersonal interactions during the design process.","uncertainty; complexity; foresight; retrospective","en","conference paper","The Design Research Society","","","","","","","","","","Marketing and Consumer Research","","",""
"uuid:5839bb19-a7f7-4726-b60b-3c44b0af8f5c","http://resolver.tudelft.nl/uuid:5839bb19-a7f7-4726-b60b-3c44b0af8f5c","Technical feasibility of a Dutch radioactive waste repository in Boom Clay: Tunnel crossings","Yuan, Jun; Vardon, P.J. (TU Delft Geo-engineering); Hicks, M.A. (TU Delft Geo-engineering); Hart, J (NRG (Nuclear Research and Consultancy Group) Petten); Fokker, PA (TNO)","","2017","OPERA-PU-TUD321b
Radioactive substances and ionizing radiation are used in medicine, industry, agriculture, re- search, education and electricity production. This generates radioactive waste. In the Neth- erlands, this waste is collected, treated and stored by COVRA (Centrale Organisatie Voor Radioactief Afval). After interim storage for a period of at least 100 years radioactive waste is intended for disposal. There is a world-wide scientific and technical consensus that geological disposal represents the safest long-term option for radioactive waste. Geological disposal is emplacement of radioactive waste in deep underground formations. The goal of geological disposal is long-term isolation of radioactive waste from our living environ- ment in order to avoid exposure of future generations to ionising radiation from the waste. OPERA (OnderzoeksProgramma Eindberging Radioactief Afval) is the Dutch research pro- gramme on geological disposal of radioactive waste. Within OPERA, researchers of different organisations in different areas of expertise will cooper- ate on the initial, conditional Safety Cases for the host rocks Boom Clay and Zechstein rock salt. As the radioactive waste disposal process in the Netherlands is at an early, conceptual phase and the previous research programme has ended more than a decade ago, in OPERA a first preliminary or initial safety case will be developed to structure the research necessary for the eventual development of a repository in the Netherlands. The safety case is conditional since only the long-term safety of a generic repository will be assessed. OPERA is financed by the Dutch Ministry of Economic Affairs and the public limited liability company Electriciteits- Produktiemaatschappij Zuid-Nederland (EPZ) and coordinated by COVRA. Further details on OPERA and its outcomes can be accessed at www.covra.nl.","Boom Clay; feasibility; radioactive waste disposl; reliability; tunnel modelling; uncertainty","en","report","Delft University of Technology","","","","","","","","","","Geo-engineering","","",""
"uuid:b56ecaa6-80a8-46b0-aef8-f7487d7d5a13","http://resolver.tudelft.nl/uuid:b56ecaa6-80a8-46b0-aef8-f7487d7d5a13","Real time floodrisk management","Kolen, B. (TU Delft Safety and Security Science; HKV Consultants); Zethof, Marit (HKV Consultants); de Bruijn, Karin (Deltares); Hazenoot, Evert (Waterschap Rivierenland)","","2017","The central issue for authorities (as well as the public) is how and when to respond to forecasted extreme water levels on rivers, lakes and along the coast and large-scale flooding is an actual risk. The decision-making process is influenced by contradicting information, overloads and gaps in information, rumours, uncertainties in forecasts, the consequences of a flood and the effectiveness of measures. Emergency measures can be taken to reduce the probability of flooding(e.g. placing sand bags), other measures can be taken to reduce the consequences of a flooding (such as evacuation of inhabitants). For many of these measures, decisions are made days or hours prior to the expected moment of occurrence of the flooding. Using forecasts of water levels, by definition uncertain, and forecasts of the strength of levees, decisions can be made based on the acceptability of the actual flood risk level. The concept of risk can be used to prioritise measures in case of limited time.","emergency management; flood risk; uncertainty; mapping","en","abstract","","","","","","","","","","","Safety and Security Science","","",""
"uuid:a1be9972-78e5-4e18-8a26-a27a7582ee2a","http://resolver.tudelft.nl/uuid:a1be9972-78e5-4e18-8a26-a27a7582ee2a","Interpolation in Time Series: An Introductive Overview of Existing Methods, Their Performance Criteria and Uncertainty Assessment","Lepot, M.J. (TU Delft Sanitary Engineering); Aubin, Jean Baptiste (Université de Lyon); Clemens, F.H.L.R. (TU Delft Sanitary Engineering; Deltares)","","2017","A thorough review has been performed on interpolation methods to fill gaps in time-series, efficiency criteria, and uncertainty quantifications. On one hand, there are numerous available methods: interpolation, regression, autoregressive, machine learning methods, etc. On the other hand, there are many methods and criteria to estimate efficiencies of these methods, but uncertainties on the interpolated values are rarely calculated. Furthermore, while they are estimated according to standard methods, the prediction uncertainty is not taken into account: a discussion is thus presented on the uncertainty estimation of interpolated/extrapolated data. Finally, some suggestions for further research and a new method are proposed.","comparison; review; uncertainty; methods; interpolation; criteria; OA-Fund TU Delft","en","journal article","","","","","","","","","","","Sanitary Engineering","","",""
"uuid:ae8304ba-aecf-4908-a856-f9da08cdf3ed","http://resolver.tudelft.nl/uuid:ae8304ba-aecf-4908-a856-f9da08cdf3ed","Flood Hazard Mapping: Uncertainty and its Value in the Decision-making Process","Mukolwe, M.M. (TU Delft Water Resources)","Solomatine, D.P. (promotor); Di Baldassarre, G (promotor); Delft University of Technology (degree granting institution)","2016","Computers are increasingly used in the simulation of natural phenomena such as floods. However, these simulations are based on numerical approximations of equations formalizing our conceptual understanding of flood flows. Thus, model results are intrinsically subject to uncertainty and the use of probabilistic approaches seems more appropriate. Uncertain, probabilistic floodplain maps are widely used in the scientific domain, but still not sufficiently exploited to support the development of flood mitigation strategies. In this thesis the major sources of uncertainty in flood inundation models are analyzed, resulting in the generation of probabilistic floodplain maps. The utility of probabilistic model output is assessed using value of information and the prospect theory. The use of these maps to support decision making in terms of floodplain development under flood hazard threat is demonstrated.","uncertainty; probabilistic flood map; floodplain planning","en","doctoral thesis","CRC Press / Balkema - Taylor & Francis Group","978-1-138-03286-6","","","","Dissertation submitted in fulfilment of the requirements of the Board for Doctorates of Delft University of Technology and of the Academic Board of the UNESCO-IHE Institute for Water Education.","","","","","Water Resources","","",""
"uuid:23eeef94-43fc-4c17-bca4-816569150bcc","http://resolver.tudelft.nl/uuid:23eeef94-43fc-4c17-bca4-816569150bcc","Operational flood forecasting, warning and response for multi-scale flood risks in developing cities","Rogelis Prada, M.C. (TU Delft Environmental Fluid Mechanics)","Mynett, A.E. (promotor); Werner, MGF (copromotor); Delft University of Technology (degree granting institution)","2016","Flood early warning systems are recognized as one of the most effective flood risk management instruments when correctly embedded in comprehensive flood risk management strategies and policies. Many efforts around the world are being put in place to advance the components that determine the effectiveness of a flood early warning system. The aim of this research is to contribute to the understanding of the risk knowledge and forecasting components of flood early warning in the particular environment of tropical high mountains in developing cities. These represent a challenge taking into account the persistent lack of data, limited resources and often complex climatic, hydrologic and hydraulic conditions. The contributions of this research are intended to advance the knowledge required for design and operation of flood early warning in data-scarce watersheds from a hydrological perspective, without neglecting the crosscutting nature of flood early warning in the flood risk management process.","rainfall field interpolation; debris flows; flash floods; mountain hazards; flood risk; vulnerability; hydrological models; páramo; uncertainty; flood forecasting; ensemble; Weather Research and Forecasting (WRF) model; numerical weather models","en","doctoral thesis","CRC Press / Balkema - Taylor & Francis Group","978-1-138-03003-9","","","","","","","","","Environmental Fluid Mechanics","","",""
"uuid:055795fb-611e-4e04-b431-fd0c377581f1","http://resolver.tudelft.nl/uuid:055795fb-611e-4e04-b431-fd0c377581f1","On the role of model structure in hydrological modeling: Understanding models","Gharari, S.","Savenije, H.H.G. (promotor)","2016","Modeling is an essential part of the science of hydrology. Models enable us to formulate what we know and perceive from the real world into a neat package. Rainfall-runoff models are abstract simplifications of how a catchment works. Within the research field of scientific rainfall-runoff modeling, the focus is shifting from performance to consistency with fundamental principles of hydrological processes. Despite all efforts there are still gaps in our understanding of how real catchments work. Additionally there are enormous endeavors to understand the behavior of rainfall-runoff mechanisms within a catchment. Examples of research items that characterize system behavior are; water residence time, travel time, differences between velocity and celerity, use of tracers and remote sensing techniques. Meanwhile not much attention is given to understanding how all this knowledge should be implemented in a model. This thesis is an attempt to understand the role of model structure and the related assumptions in making better use of the available knowledge on catchment processes. The starting point of this thesis is building a hydrological model based on topographical landscape units, using a newly introduced descriptor called HAND (Height above nearest drainage). The purpose of this part of research was to build a model which contains our perception of how rainfall-runoff mechanisms work for distinct landscapes, classified based on HAND and slope. Three different models have been developed from simple to complex. A simple model has a limited number of constraints while a complex model can have various constraints imposed. To have a realistic behavior of these models a set of constraints has been defined and imposed on the model parameters as well as model fluxes and states in a comparative fashion. After simulations with these models, it is observed that even without calibration and just by constraining, the complex model was able to simulate discharge within an acceptable range. Moreover, without the constraints the complex model shows higher parity with observation compared to the simple model. To refine this method even more, a simple parameter search strategy is proposed to satisfy all imposed constraints (chapters 3, 4 and 5). The fact that adding proper constraints can have such a positive impact on the accuracy of the outcome is the basis for further research into the structural elements and type of constraints imposed on the model. However to study the effect of structural changes in a model, the dominant effect of assumptions on state-discharge relations (parameterizations) had to be diminished. To achieve this, weak parameterization was introduced building on the concept of random functions. Using weak parameterization, it was found that structural complexity can improve themodel’s correspondence with observed data significantly. It was also found that there is a balance between model complexity, imposed constraints and performance of the model. Although increased complexity of a model can improve its performance, an over-constrained model can deviate from observed data. This means that, although a complex model may be structurally more favorable, the constraints, based on expert knowledge, should be set-up in such a way as to minimize the bias of the model outcome. This research can be a basis for the dialog between modelers and experimentalists. This approach can be used to investigate the behavior of the model in relation to its structural configuration, parameterizations and the set of imposed constraints (chapter 6). The last part of this thesis (chapter 7) covers the introduction of the concept of time consistent model parameters. Traditionally a part of the time series is kept for a separate evaluation of the model. However, during so-called SubPeriod calibration (SuPer calibration), parameter sets are evaluated based on their resulting model performance for different sub-periods of the entire observed time series. The parameter sets identified by SuPer calibration are different from the optimal parameter set found by calibration over the same period of data. This thesis concludes with a critical review of this research work together with discussions that took place during the research (chapter 8). This chapter is reflecting the novelty and deficiency of presented work and the battles to be fought in future.","rainfall-runoff modeling; model structure; uncertainty; information","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Water Management","","","","49.85, 6.10"
"uuid:68ed4345-599a-44a1-83d0-72a5f895ba70","http://resolver.tudelft.nl/uuid:68ed4345-599a-44a1-83d0-72a5f895ba70","Device-independent two-party cryptography secure against sequential attacks","Kaniewski, J. (TU Delft Network Architectures and Services; TU Delft QuTech Advanced Research Centre; National University of Singapore); Wehner, S.D.C. (TU Delft Quantum Internet Division; TU Delft Quantum Information and Software; TU Delft QuTech Advanced Research Centre)","","2016","The goal of two-party cryptography is to enable two parties, Alice and Bob, to solve common tasks without the need for mutual trust. Examples of such tasks are private access to a database, and secure identification. Quantum communication enables security for all of these problems in the noisy-storage model by sending more signals than the adversary can store in a certain time frame. Here, we initiate the study of device-independent (DI) protocols for two-party cryptography in the noisy-storage model. Specifically, we present a relatively easy to implement protocol for a cryptographic building block known as weak string erasure and prove its security even if the devices used in the protocol are prepared by the dishonest party. DI two-party cryptography is made challenging by the fact that Alice and Bob do not trust each other, which requires new techniques to establish security. We fully analyse the case of memoryless devices (for which sequential attacks are optimal) and the case of sequential attacks for arbitrary devices. The key ingredient of the proof, which might be of independent interest, is an explicit (and tight) relation between the violation of the Clauser–Horne–Shimony–Holt inequality observed by Alice and Bob and uncertainty generated by Alice against Bob who is forced to measure his system before finding out Alice's setting (guessing with postmeasurement information). In particular, we show that security is possible for arbitrarily small violation.","quantum cryptography; device-independent; two-party cryptography; CHSH inequality; uncertainty; nonlocality","en","journal article","","","","","","","","","","Quantum Internet Division","Network Architectures and Services","","",""
"uuid:22555264-c31c-4568-952c-490c9490ade9","http://resolver.tudelft.nl/uuid:22555264-c31c-4568-952c-490c9490ade9","Low-cost Space-borne Data for Inundation Modelling: Topography, Flood Extent and Water Level","Yan, K.","Solomatine, D.P. (promotor); Di Baldassarre, G. (promotor)","2015","Floods are among the most damaging natural hazards and their impacts have been dramatically increasing worldwide over the past decades. As most basins of the world are ungauged or poorly gauged and some measurement networks are continuously under decline, the spatial distribution of flood hazard is often difficult to estimate because the input data needed for flood inundation modelling (e.g. topographies, flood extents, water levels) are often not available. A unique opportunity is nowadays provided by the ongoing development of remote sensing data, such as the low-cost, space-borne data. In particular, the development of new remotely sensed data sources has not only shifted flood modelling from a datapoor to a data-rich environment, but also provided a paradigm shift in flood modelling: from developing more sophisticated flood models to evaluating potential of remote sensing data. There is a general consensus that the increased availability and quality of those low-cost remote sensing data will be valuable for improving prediction in ungauged basins. However, their value and potential in supporting hydraulic modelling of floods are still not sufficiently explored in view of the unavoidable, intrinsic uncertainty affecting any modeling exercise. In this context, this thesis aims to explore the potential and limitations of low-cost, space-borne data in flood inundation modelling under uncertainty. In our research work, we analyze the potential in supporting hydraulic modelling of floods of: NASA’s SRTM (Shuttle Radar Topographic Mission) topographic data, SAR (Synthetic Aperture Radar) satellite imagery and radar altimetry. The characteristics of those data, and their pros and cons for inundation modelling are discussed. For example, SRTM`s global coverage and relatively low vertical error on low-slope areas are in favour of floodplain modelling, while its absence of in-channel geometry information would hamper its application in flood studies. Low-cost SAR imagery`s day-night, all-weather, cloud-free acquisition are particularly useful for flood extent monitoring, while its low resolution could induce equifinality in inundation model conditioning. Radar altimetry`s reliable water level measurements over large rivers provides opportunities for flood model calibration and evaluation, while its low space-time frequency limits the application in areas such as flood forecasting. To this end, research work has been carried out by either following a model calibration-evaluation approaches or by explicitly considers major sources of uncertainty within a Monte Carlo framework. To generalize our findings, three river reaches with various scales (from medium to large) and topographic characteristics (e.g. valley-filling, two-level embankments, large and flat floodplain) are used as test sites. Thus, specific modelling exercises are implemented with slight, tailor-made modifications to deal with practical issues, such as the actual data availability, the characteristics of flood events etc. The usefulness of the low-cost space-borne data is quantitatively analyzed. Lastly, an application of SRTM-based flood modelling of a large river is conducted to highlight the challenges of predictions in ungauged basins. The outcomes of the study provide indications on the potential and limitations of low-cost, space-borne data in supporting flood inundation modelling under uncertainty. Specifically, DEM resolution is often less of an issue than its vertical accuracy, as long as the coarse resolution allows the representation of flood patterncontrolling topographic features for the flood modelling issue, which is often not the case in urban flood studies. Thus, the thesis includes and discusses the usefulness of these data according to specific modelling purpose (e.g. re-insurance, planning, design). Moreover, topographic uncertainty could be compensated by other sources of uncertainties in hydraulic modelling if they are explicitly taken into account. The model prediction based on SRTM can be very close to that based on high-resolution, high-accuracy topographic data under other sources of uncertainty. However, besides modelling purpose and uncertainty considered, their actual usefulness could be affected by several other factors, such as the scale of the river under study, flood frequency, and the choice of modelling tools. Furthermore, the issue of in-channel information absent in SAR-derived DEMs are also discussed. It could be partially resolved by using either the global river depth dataset, or depth estimating from hydraulic geometry theory or model parameterization. Lastly, we discuss the upcoming satellite missions, which could potentially impact the way we model flood inundation patters.","SRTM topography; uncertainty; SAR imagery; flood extent","en","doctoral thesis","Taylor & Francis Group","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:d9cd85d4-2647-49e4-8e7c-df66e27681d3","http://resolver.tudelft.nl/uuid:d9cd85d4-2647-49e4-8e7c-df66e27681d3","Very long term development of the Dutch Inland Waterway Transport System: Policy analysis, transport projections, shipping scenarios, and a new perspective on economic growth and future discounting","Van Dorsser, J.C.M.","Ligteringen, H. (promotor); Van Wee, G.P. (promotor)","2015","This thesis addresses how a new method for the evaluation of policies with a very long term impact on the Dutch Inland Waterway Transport (IWT) system can be developed. It proposes an outline for a very long term transport model, prepares a number of very long term scenarios, and indicates that a different perspective on economic growth and future discounting is required to obtain realistic projections and develop sensible policies for issues with a very long term impact. Extended summary report: http://resolver.tudelft.nl/uuid:ef349716-b484-4820-a02a-d1cd13bc51b8","very long term; inland waterway transport; policy analysis; uncertainty; transport modelling; probabilistic projections; climate change; intermodal transport; scenario analysis; delta scenarios; economic growth; future discounting","en","doctoral thesis","TRAIL Research School","","","","","","","2015-05-13","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:91e2668d-83e1-4ace-b110-3dc2109238e5","http://resolver.tudelft.nl/uuid:91e2668d-83e1-4ace-b110-3dc2109238e5","Climate Change Impacts on River Floods: Uncertainty and Adaptation","Wang, L.","Vrijling, J.K. (promotor); Van Gelder, P.H.A.J.M. (promotor)","2015","The modelling frameworks, which include greenhouse gas emission scenarios, climate models, downscaling methods and hydrological models, are generally used to assess climate change impacts on river floods. In this research, the uncertainty associated with each component of the modelling framework is analysed with particular reference to climate change impacts on flood frequency. A method of risk-averse economic optimisation has been proposed for adapting river dikes to climate change under uncertainty. The Huai River Basin in China has been selected as a case study. The outputs of climate models, i.e., General Circulation Models (GCMs), under greenhouse gas emission scenarios have been commonly used as fundamental inputs of the climate change impact assessments. The analysis in this thesis employed the climate model projections of the WCRP CMIP3 and CMIP5 datasets. In Chapter 2, a brief introduction of emission scenarios, as well as a preliminary analysis of the simulative ability and future projections of the participating climate models, is provided. The results confirm the necessity to bias-correct and downscale the climate model outputs before being used in impact-related studies. The annual mean temperature in the study area is suggested to increase up to 8oC at the end of this century under a high greenhouse gas emission scenario without mitigation measures. The standard deviation of precipitation intensity is suggested to increase, especially in summer, which may in the future lead to high-magnitude floods. Empirical statistical downscaling methods are becoming increasingly popular in climate change impact assessments that require downscaling multi-GCM projections. In Chapter 3 empirical statistical downscaling methods are classified based on calibration strategies and statistical transformations. Ten combinations of calibration strategies and transformation methods were used to represent a range of empirical statistical downscaling methods. To test the performance of these methods in downscaling daily precipitation and temperature, an inter-model cross validation was carried out using an ensemble of 16 GCMs. These downscaling methods were further applied to downscale the climate for the future period to assess the associated uncertainties. The results show that the change factor based methods outperform the bias correction based methods in projecting the probability distribution of downscaled daily temperature. With the change factor calibration strategy, simply adding (for temperature) or multiplying (for precipitation) the mean change factor is sufficient to represent most of the relative changes projected by GCMs. The use of quantile based methods appear to be advantageous only at the tails of the distribution. More sophisticated bias correction based methods are needed to remove the biases in the higher-order statistics of the GCM outputs. The two calibration strategies led to fundamentally different temporal structures and spatial variability of the downscaled climatic variables. Bias correction based methods produced larger uncertainty bounds of inter-annual variability than the change factor methods. For downscaled precipitation, the uncertainty arising from the downscaling methods is comparable to the uncertainty arising from GCMs, while more uncertainty is introduced by calibration strategies than statistical transformation methods. There is a growing consensus that the performance of hydrological models should be routinely evaluated before being used in impact-related studies. The uncertainty, which stems from transferring calibrated models to a changing future climate, is receiving increasing attention. Chapter 4 assesses the uncertainties associated with the parameter calibration of the lumped Xinanjiang hydrological model when assessing the climate change impacts on river flow. The transferability of model parameters was tested in the context of historical climate variability using the differential split-sample test. The parameters calibrated from the periods representing differing climatic conditions were used to project future river flow in a changing climate. The uncertainties in projected future river flows stemming from the choice of calibration periods and parameter equifinality were compared. The results show that the transferability of the parameters calibrated from a wet period to a dry period is poorer than the other way around. The model error as well as the variability in the simulations due to equifinality increase with the increase of the difference in rainfall between the calibration and validation periods. The uncertainty due to the choice of calibration periods takes the majority of the total parameter uncertainty in the projected future mean discharge. When the calibration period contains enough information on climate variability, the equifinality effect and the choice of calibration periods contribute comparable magnitudes of uncertainty in terms of extreme discharge. Five sources of uncertainty mentioned above were compared in Chapter 5, i.e. GCM structure, greenhouse gas emission scenario, downscaling method, choice of period for calibrating the hydrological model, and non-uniqueness of hydrological parameters. Multiple samples of flood frequency curves were generated through the combinations of different emission scenarios, GCMs, downscaling methods and hydrological model settings. All samples were given equal weights in the analysis. The results show that the future flood magnitude is expected to increase, not only due to the increase in mean precipitation, but also due to the increase in variation of precipitation. Nonetheless, there is still a small likelihood that the flood quantiles with a high return period (above 20 years) will decrease in the future. The results of uncertainty comparison suggest that the GCM structure is the dominant source of uncertainty, emission scenarios and empirical statistical downscaling methods also result in considerable uncertainty, and the uncertainties related to hydrological model are less than those related to other uncertainty sources. To guarantee a safe flood defence in a changing environment, the adaptation to climate change needs to be considered in the design of river dikes. However, the large uncertainty in the projections of the future climate leads to varied estimations of future flood probability. How to cope with the uncertainties in future flood probability under climate change is an inevitable question in adaptation decision-makings. In Chapter 6, the uncertainty introduced by climate projections was integrated into the ‘expected predictive flood probability’, and the risk-aversion attitude was introduced in the adaptation of river dikes. The uncertainty in the climate change projections on flood probability was represented by the uncertainty in the parameters of the probabilistic model. This parameter uncertainty was estimated based on the outputs from the GCMs participating in IPCC AR4. The parameter uncertainty, estimated from the selected GCMs under different scenarios, was integrated into the expected predictive probability of flooding, which was then used in the risk-averse economic optimization. Different optimal results were obtained based on varied values of the risk-aversion index which represents the risk-averse altitude of decision makers. The case of a dike ring area in the Bengbu City in the Huai River Basin is studied as an example using the proposed approach. The results show that the uncertainty of climate change decreases the optimal safety level and increases the optimal dike heightening up to 8.23 m (with the risk-aversion index of 1.5) in a gradually changing climate. The value would be even larger if the climate will change sooner. Integrated adaptive measures rather than only dike heightening are needed to respond to the uncertain impacts in the future. The proposed approach enables decision makers to cope with climate change and the associated uncertainty by adjusting the level of risk aversion.","climate change; river flood frequency; uncertainty; adaptatioin","en","doctoral thesis","VSSD","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:5930fbfb-e2e8-4936-8bae-28724909d803","http://resolver.tudelft.nl/uuid:5930fbfb-e2e8-4936-8bae-28724909d803","Towards improved handling of uncertainty in cost-benefit analysis: Addressing the ‘price-quality’ and ‘communication’ dilemmas","Mouter, N.; Holleman, M.; Calvert, S.C.; Annema, J.A.","","2015","An important limitation of Cost-Benefit Analysis (CBA) is the inherent uncertainty in estimations of future welfare effects. In this paper, we argue that consideration of the ‘price-quality’ dilemma and the ‘communication’ dilemma is useful to explain and improve the handling of uncertainty in CBA. The ‘price-quality’ dilemma refers to the trade-off between the quality of welfare effect estimations and the costs of providing these estimations. Instruments to produce good quality effect estimates (including uncertainties) can be expensive both in monetary terms and time. We discuss the application of probabilistic traffic models as a promising example of how the ‘price-quality’ dilemma can be solved. The ‘communication’ dilemma refers to the observation that both a poor communication and a too prominent communication of uncertainties can cause problems for decision-makers. We argue that cognitive psychological theory provides useful perspectives to solve this dilemma, by providing a psychological framework which might help to explain why different types of people process CBA information differently. The results of this research may enhance first insights into the questions how the two dilemmas can be solved.","cost-benefit analysis; probabilistic dynamic traffic modelling; social psychology; transport appraisal; uncertainty","en","journal article","Delft University of Technology, Transport and Logistics Group","","","","","","","","Technology, Policy and Management","Engineering, Systems and Services","","","",""
"uuid:ef349716-b484-4820-a02a-d1cd13bc51b8","http://resolver.tudelft.nl/uuid:ef349716-b484-4820-a02a-d1cd13bc51b8","Very long term development of the Dutch Inland Waterway Transport System: Policy analysis, transport projections, shipping scenarios, and a new perspective on economic growth and future discounting: Extended summary report","Van Dorsser, J.C.M.","Wolters, M.A. (contributor)","2015","This report, that provides an extended summary of a similar named thesis, addresses how a new method for the evaluation of policies with a very long term impact on the Dutch Inland Waterway Transport (IWT) system can be developed. It proposes an outline for a very long term transport model, prepares a number of very long term scenarios, and indicates that a different perspective on economic growth and future discounting is required to obtain realistic projections and develop sensible policies for issues with a very long term impact.","very long term; inland waterway transport; policy analysis; uncertainty; transport modelling; climate change; intermodal transport; scenario analysis; delta scenarios; economic growth; future discounting","en","report","Rijkswaterstaat","","","","","","","2015-05-13","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:733536e7-c97f-40d3-aa08-ef353537d946","http://resolver.tudelft.nl/uuid:733536e7-c97f-40d3-aa08-ef353537d946","Challenges in Delivering Green Building Projects: Unearthing the Transaction Costs (TCs)","Qian, K.; Chan, E.H.W.; Khalid, A.G.","","2015","Delivering green building (GB) projects involve some activities that are atypical in comparison with conventional buildings. Such new activities are characterized by uncertainty, and they incur hidden costs that have not been expected nor are they readily appreciated among the stakeholders. This paper develops a typology and chronology to examine the new activities that are associated with transaction costs (TCs) in the real estate development process (REDP) of green building. Through in-depth interviews with representatives from the major developers in Hong Kong who have experiences in GB practice, this study aims to unearth TCs involved at the critical stages of the REDP. Apart from reconfirming the early project planning stage as the most critical in the consideration of TCs, the study results also identified “extra legal liability risk of the GB product” as the major concern for any GB developer in Hong Kong. The key additional activities that bring significant TCs in developing GB are identified and compared to their traditional counterparts. In turn, project managers not only have to pursue overall cost management whilst winning more business, but they also have to pay particular attention to sustainability in order to minimize hidden societal costs. The study also provides a reference for governments and professionals that will aid in forming policy as well as advance the practice of the GB market by optimizing the societal costs.","green building (GB); transaction costs (TCs); uncertainty; real estate development process (REDP); government policy; OA-Fund TU Delft","en","journal article","MDPI","","","","","","","","Architecture and The Built Environment","OTB","","","",""
"uuid:ec57b16b-0beb-4064-a621-9c99b79ea6cb","http://resolver.tudelft.nl/uuid:ec57b16b-0beb-4064-a621-9c99b79ea6cb","A numerical and reliability-based investigation into the technical feasibility of a Dutch radioactive waste repository in Boom Clay","Arnold, P. (TU Delft Geo-engineering); Vardon, P.J. (TU Delft Geo-engineering); Hicks, M.A. (TU Delft Geo-engineering); Fokkens, Jan (NRG (Nuclear Research and Consultancy Group) Petten); Fokker, Peter A. (TNO)","","2015","OPERA-PU-TUD311
The Onderzoeks Programma Eindberging Radioactief Afval (OPERA) is the third national research programme for the geological disposal of radioactive waste in the Netherlands, operating during the period 2011 to 2016. This document is the final report of Work Package 3.1, where the principal technical feasibility of the current OPERA reference design of a radioactive waste disposal facility, in Boom Clay at a depth of about 500m was investigated, during the period 12-2012 till 12-2014.