"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:e3f2d8a8-048f-49a0-ac2f-347f224c55e4","http://resolver.tudelft.nl/uuid:e3f2d8a8-048f-49a0-ac2f-347f224c55e4","Indoor Localization for Efficient Bike-Sharing Management","Visser, Berend (TU Delft Electrical Engineering, Mathematics and Computer Science)","Venkatesha Prasad, Ranga Rao (mentor); Song, Q. (graduation committee); Willemsen, G.M. (graduation committee); Delft University of Technology (degree granting institution)","2024","In response to the growing demand for sustainable transportation solutions, bike-sharing systems have gained prominence in supporting an eco-friendly means of commuting. Within this landscape, Skopei, a forward-thinking company specializing in innovative sharing propositions, has developed a smart bike lock capable of autonomous rentals and returns. This master’s thesis delves into the application of radio frequency-based distance measurements to create an indoor positioning system for the efficient management of bike storage. Specifically, the system is designed to determine whether bikes have been correctly parked at docking locations, enabling users to conclude their rentals autonomously. The architecture of this system uses a network of anchor nodes (known-location routers) that should ascertain the positions of mobile nodes (bikes) within the bicycle storage area. Notably, the solution developed in this thesis employs sophisticated distance measurement techniques, including frequency hopping and phase shift analysis. By finding the amplitude and phase shift over multiple frequencies, we can find the channel impulse response and estimate the distance using machine learning. We employ a novel Multi-layer Perceptron neural network regressor to improve the accuracy in the presence of complex environmental factors in bike storage environments. In the bike storage test case, we achieved a mean absolute error in position estimation of 1.68m compared to 3.80m of a naive approach. We improved the parking state classification from 75.99% of a naive approach to 98.09% with our machine-learning-based approach. This thesis underscores the importance of cutting-edge distance measurement methods and real world field studies in advancing indoor positioning systems, specifically for smart bike storage management. By bridging the gap between technology and sustainable transportation, this work aims to make urban bike-sharing systems more scalable, efficient, user-friendly, and environmentally conscious.","Indoor positioning; Multilayer Perceptron; Machine Learning (ML); Localization","en","master thesis","","","","","","","","2026-01-22","","","","Electrical Engineering | Embedded Systems","",""
"uuid:daa27f4b-d1f6-4be7-b143-558425a43d60","http://resolver.tudelft.nl/uuid:daa27f4b-d1f6-4be7-b143-558425a43d60","Surface Energy Balance Modeling in Urban Environments: A numerical study on the influence of thermal radiation on the urban heat island effect using a one-way coupled RANS approach","Visser, Alje (TU Delft Applied Sciences)","Kenjeres, S. (mentor); Bera, B. (graduation committee); de Roode, S.R. (graduation committee); Delft University of Technology (degree granting institution)","2023","A phenomenon that compromises the health of city inhabitants is the urban heat island (UHI) effect. This effect is mainly driven by thermal radiation and designates the typically higher air temperature in cities compared to the surrounding rural areas. Over 55% of the world’s population lives in cities, and with this percentage set to rise to more than 65% by 2050, it is vital to model the urban climate to be able to mitigate the UHI-effect. In this study, the surface energy balance (SEB) is modeled in urban environments using a one-way coupled RANS 𝑘 − 𝜖 approach in order to gain fundamental insights into the influence of thermal radiation on the UHI-effect. The SEB model is built mechanism-by-mechanism, adding in different physical mechanisms one at a time and validating the model at each step with literature- or theoretical values. The SEB model showed a good agreement with experimentally found values for the effect of surface irregularity of an urban structure on the absorption and reflection of incident solar radiation. A good agreement was also found with theoretical values for the longwave radiation and conductive heat flux part of the SEB model. Subsequently, a study was done on a 2D street canyon to compare the model with literature results. This study showed a good agreement for the radiative fluxes, but a lesser agreement for the conductive- and sensible heat fluxes. A more complex scenario of an intersection between buildings was studied. It was shown that the longwave trapping effect is highly correlated with building height. Finally, the effect of wall heating on flow characteristics in a 2D street canyon was examined. For homogeneously heated walls, the SEB model showed a relatively good agreement with literature results. A study was also done with non-homogeneously heated walls. This study showed less realistic results and should be further investigated in further research.","","en","master thesis","","","","","","","","2025-08-28","","","","Applied Physics","",""
"uuid:5fa2a662-3e60-4f79-ac28-4c4a6e4aacaf","http://resolver.tudelft.nl/uuid:5fa2a662-3e60-4f79-ac28-4c4a6e4aacaf","PLAI: Positive Implementation of Generative AI in Education Through Play-Based Learning","Visser, Titus (TU Delft Industrial Design Engineering; TU Delft Human-Centered Design)","Lomas, J.D. (mentor); Gielen, M.A. (graduation committee); Delft University of Technology (degree granting institution)","2023","Generative AI has had a profound impact on various sectors since mid-2022. The rapid adoption by students poses challenges for student assessment and raises concerns about student development. This thesis delves into the subject and proposes a positive implementation in education through play-based learning. The project uses a human-centred iterative design approach, consisting of co-design workshops with children, teachers and expert interviews. The research shows that teaching children about AI and generative AI can be done from a young age using play-based learning.
The study captures the diverse perceptions of elementary school children and teachers regarding generative AI. Key findings highlight children’s concerns and needs with regards to generative AI. Cooperatively formulated design criteria point towards children’s main interests for products or services with generative AI or AI to have a play-based nature, foster creativity and inspiration, safeguard their privacy and security and help them achieve their goals.
The research in this thesis also explores educators’ perceived challenges and interests in classroom integration of generative AI. Key findings include the perceived necessity for both teachers and students to learn about generative AI, the interest across different levels of education and that the age deemed appropriate for students to be introduced to generative AI is often considered to be at the end of primary school or at the start of secondary school.
From the research several design principles are proposed to create an engaging, ethical and human-centred AI learning experience. To facilitate this experience and to spearhead the integration of generative AI into education, a company named “PLAI” is conceptualised. The company aims to implement generative AI in education in a positive way by providing learning material which stimulates engagement, creativity and social learning while safeguarding privacy and security by offering play-based and scaffolded learning in workshops. Future recommendations and plans include the development of a multi-modal generative AI model which can run locally on school servers and is alignable with their curriculum.
Limitations of this study include a lack of direct interaction and research with high school students, a need to explore text based generative AI interactions with students, and a need to assess generative AI’s long-term effects on student well-being.","Generative AI; Child-AI interaction; Teacher-AI interaction; Play-based learning; Human-Centered Design; Iterative approach; workshop design; Implementation; Education; creativity; AI Literacy","en","master thesis","","","","","","","","","","","","Integrated Product Design","","52.002627, 4.370436"
"uuid:d6644989-1269-45b0-bed1-70e7640c4c00","http://resolver.tudelft.nl/uuid:d6644989-1269-45b0-bed1-70e7640c4c00","On-chip SPAD array with IO designed for quantum sensing","van Rijs, Samantha (TU Delft Electrical Engineering, Mathematics and Computer Science); Westenbrink, Dagmar (TU Delft Electrical Engineering, Mathematics and Computer Science); Visser, Lars (TU Delft Electrical Engineering, Mathematics and Computer Science)","Ishihara, R. (mentor); Varveris, I. (mentor); van der Veen, A.J. (graduation committee); Krasnov, O.A. (graduation committee); Delft University of Technology (degree granting institution)","2023","In this Bachelor graduation project, a 16x16 Single Photon Avalanche Diode (SPAD) array is designed in 40nm TSMC CMOS for diamond single Nitrogen Vacancy center array readout. It includes an active quenching and recharge circuit (AQC), a hold-off circuit for controllable dead-time and IO electronics for off-chip communication. The chip is part of a proposed high sensitivity magnetometer based on single NV center readout with a focus on detecting cancer in biological samples. From the Quantum Integration Technology (QIT) lab, pre-designed SPADs were received to be implemented into the design together with SPAD quenching, recharge and input-output controller electronics. A SPAD model is adapted from literature for simulations of the electric behaviour of the electronics. We present a design and implementation of the Active Quenching Circuit (AQC), a design and implementation of the recharge and hold-off circuits, Input-Output (IO) interface design and implementation and the final top-level implementation ready for the next tape out. Post-layout simulations show negligible speed slowdown and distortion. The AQC has a 12ns quenching time and a 1ns recharge time, leading to a theoretical maximum count rate of 76Mc/s. The hold-off circuit has a tunable dead-time for afterpulsing reduction and 16, 16 bit parallel-in-serial-out (PISO) modules allow per-row readout of the array. The electronics are co-located with the SPADs and pixel pitch is 24𝜇m. The final chip design meets the single NV fluorescence count rate requirement of above 3 Mc/s, the 1.1x1.1 𝑚𝑚2 area requirement, the 32-pin IO requirement, the 16x16 SPAD pixel requirement and, steps have been taken to ensure acceptable crosstalk levels in the array. Finally, the SPAD array chip is designed to run on a 1GHz clock. It should interface with an FPGA that configures the hold-off circuit and reads out the SPAD status bits.","SPAD; NV centers; Single-Photon Avalanche Diode Array","en","bachelor thesis","","","","","","","","","","","","Electrical Engineering","",""
"uuid:046ed852-99cd-4f28-886e-2be4977a079e","http://resolver.tudelft.nl/uuid:046ed852-99cd-4f28-886e-2be4977a079e","Moving with Water: Creating a Flexible and Resilient City in the Face of Extreme Weather","Visser, Froukje (TU Delft Architecture and the Built Environment)","Aalbers, K.P.M. (mentor); Goncalves, J. E. (graduation committee); Delft University of Technology (degree granting institution)","2023","The built environment of the future should move with the changes the weather brings as well as evolve with slower and larger trends in our society like climate change, demographic changes, and technical advancements. By planning for the future now we can reduce obstacles for future generations of planners, designers, and governing bodies.
The built environment should be able to function well whether water is in high or low flux. Water is fluid. It is shaped by and shapes its surroundings. Cities can learn a lot from this fluidity. By increasing the flexibility of urban design, we can anticipate and move with the changes the future brings instead of being in a continuous cycle of trying to catch up. The built environment should follow the current of the future and adapt to the changes in our climate and weather. Creating a city that adapts to new circumstances and moves with water.
use radiance fields which style a whole scene instead of just the 3D reconstructed object, we have developed a method which styles an implicit surface.
We achieve this by using Implicit Differentiable Renderer (IDR), which trains, using masked
images as input, two neural networks that learn the geometry and appearance. Rendered views of the object are styled using 2D neural style transfer (NST) methods, and the style information is used to further train the appearance network to display the given style. With Masked deferred back-propagation we are able to optimize the appearance renderer, which is normally trained on only patches of the rendered image to save memory, while using style
transfers designed for full-resolution images. We showcase different results from our method using different 3D reconstruction datasets and style images, and showcase how to implement a user-created dataset. We carry out
extensive tests on what effects different parameters have on the final result. Comparing our results to similar 3D style methods demonstrates that our method performs equally well in achieving faithful style transfer, while having the benefits of creating high quality geometry and only styling the reconstructed surface.","","en","master thesis","","","","","","","","","","","","Geomatics","",""
"uuid:d818a87a-9c98-403a-aaa4-3ad80b360f72","http://resolver.tudelft.nl/uuid:d818a87a-9c98-403a-aaa4-3ad80b360f72","Removing shared faces in 3D datasets for numerical simulations","Therias, Adele (TU Delft Architecture and the Built Environment); Theodoridou, Eleni (TU Delft Architecture and the Built Environment); PAPADIMITRIOU, CHRYSANTHI (TU Delft Architecture and the Built Environment); Visser, Fabian (TU Delft Architecture and the Built Environment); Zhang, Fengyan (TU Delft Architecture and the Built Environment); Panagiotidou, Ioanna (TU Delft Architecture and the Built Environment)","Garcia Sanchez, C. (mentor); Pađen, I. (graduation committee); Delft University of Technology (degree granting institution)","2022","Currently more than 4 billion people live in urban areas around the globe, a trend that is expected to be increased in the upcoming years. While urbanisation provides the space for innovation and new opportunities, in the meantime physical, technical and social challenges are rising and the cities’ vulnerability is increasing. A tool to tackle these issues are Computational Fluid Dynamics
(CFD) simulations, which can provide insight in various topics.
CFD simulations are valuable for modelling complex urban phenomena such as wind flow, microclimates and thermal comfort. A CFD requires as an input a 3D geometric dataset that represents objects in the urban environment which are most commonly buildings and then according to this input the air flow is simulated around it.
When creating geometries automatically for CFD simulations, several clean up tasks must be completed for them to be usable without any issues. One of the problems arising is related to the redundant faces shared between adjacent buildings, which have no purpose for outdoor flow simulations and cause complications when creating the mesh that is needed for the CFD. This
synthesis project focuses on addressing the aforementioned issue by removing the shared faces.
The ultimate goal of this project was to create an open-source product that can efficiently and in an automated way remove the adjacent faces between buildings. The benefits will be imminent during the meshing process, as we strive to reduce the time that consultancies spend fixing the input geometries before running a CFD simulation, along with an overall improved user experience.
This report is organised in four main sections. The first section is the general introduction of the issue that needs to resolved. The second section defines more in depth the problem and sets the research questions, in accordance to that, in the third section the research methodology is developed. In the fourth section the results of both methods are presented. The fifth sectionfocuses on a reflection of the project, while the sixth section presents the final conclusions. Finally, the seventh section contains the specifics of the project management itself.
The project was carried out in cooperation with Dassault Syst`emes and is developed in the context of the GEO1101 course in MSc Geomatics TU Delft. In addition to this report we have created a GitHub repository (https://github.com/Fabisser/facesBgone) that contains the source code of the two methods.","CFD; Geometry Preparation; Adjacent faces; 3D modelling","en","student report","","","","","","https://github.com/Fabisser/facesBgone R GitHub Repository of ""facesBgone"" project.","","","","","","Geomatics","",""
"uuid:a76d8f50-81a7-40c3-92e1-fd8ffb92bf60","http://resolver.tudelft.nl/uuid:a76d8f50-81a7-40c3-92e1-fd8ffb92bf60","Implementing social contagion for the Dutch neighborhood approach of the energy transition","Visser, Rose (TU Delft Industrial Design Engineering)","van Engelen, J.M.L. (mentor); van Dam, Sonja (graduation committee); Aartsma, Yael (graduation committee); Delft University of Technology (degree granting institution)","2022","95 % of all the buildings in the Netherlands rely on natural gas for heat. But in just 30 years, all of these 7 million homes must have said goodbye to gas forever. A complex project, since the alternative to gas, is not a one size fits all solution. There are several options and their feasibility is highly dependent on the neighborhood context. Therefore, municipalities became responsible for the Dutch energy transition. In the earlier energy transition from coal to gas in the 1980s, there were clear economic benefits for residents. Now, despite the record-breaking gas prices, the long-term returns on investments are uncertain while there are many short-term inconveniences.
The technical side of the energy transition tends to overshadow the social dimension. The technical challenges are clear and the path to work on the viable solution is familiar since the municipalities have been in charge of similar infrastructure projects. The social transition, however, is highly dependent on the local situation and requires time. The municipalities have to become the spider that holds the web of stakeholders together to make this complex process work. To help municipalities stay in charge of the energy transition, Stroomversnelling developed Wijkkompas: a process management tool that guides municipalities from ‘Transitie Visie Warmte’ to ‘Wijk Uitvoerings Plan’. Wijkkompas helps municipalities balance the social and technical side of the transition.
On the social side of the transition, participation is a well-known factor that municipalities already take into account. The goal of participation is to make informed decisions together with residents through representation. However, through participation alone municipalities will not be able to reach all seven million households. Therefore the goal of this thesis is to effectively apply the social contagion method to the Wijkkompas tool since social contagion is a process in which the network in the neighborhood will take on the task of activating residents themselves.
Social contagion theory teaches us both information and behavior can be transmitted in a network. Each has its optimal way of traveling through the network and thus has an optimal seeding strategy. For the energy transition, the transmitting behavior with the snowball strategy can be very valuable. Holistically it would be best to separate the participation from the social contagion approach and run a parallel process. However, for the social transition, we rely on volunteers who are busy and scarce. Therefore we propose a six-step model that adequately combines both techniques for a successful neighborhood transition.
The biggest impact can be made when municipalities find the courage to try out this new activation method. The Lopend vuurtje box, designed in this project, uses the principles of social contagion to spread the method through the inter-municipal network. The box invites its receivers to try out the method for themselves through personal assignment, a small experiment, an educational flyer, and by becoming part of the Lopend vuurtje network by sending the box further along its journey through the Dutch municipal network.","Energy transition; Social contagion; Strategic Design; Built environment; Behaviour Change; Toolkit; Neighbourhood","en","master thesis","","","","","","","","","","","","Strategic Product Design","",""
"uuid:4c7b4c8f-1797-447e-8854-d9440e2f4a18","http://resolver.tudelft.nl/uuid:4c7b4c8f-1797-447e-8854-d9440e2f4a18","Probabilistic Risk Assessment of Urban Drainage Systems: Exploring Hanoi’s inundation problems using PCSWMM","Visser, Florida (TU Delft Civil Engineering and Geosciences)","Rutten, M.M. (mentor); Langeveld, J.G. (graduation committee); Mai Van, C. (graduation committee); Eulderink, J.L.F. (mentor); Delft University of Technology (degree granting institution)","2022","This research explores the frequent urban flooding problems typically experienced in South-East Asian cities. Heavy rainfall during the monsoon period in combination with rapid urbanisation in the past decades causes an increasing amount of inundation events in the case study area Hanoi. The damage caused by these floods results in major economic losses that affect local citizens as well as governmental authorities. Flood waters are often heavily polluted with sewer water, threatening public health
and reducing the overall livability of Hanoi. In addition, inundated streets are difficult to navigate, and waves induced by vehicles can lead to dangerous situations for pedestrians and other road users. This research aims to have a better understanding of the failure mechanisms of Hanoi’s drainage system, and the risks associated with each mechanism. Since there is no standard methodology for probabilistic risk assessment of urban drainage systems, the methodology for levee assessment was adopted and adjusted to the field of urban drainage. This straight-forward method is transferable to other study areas and results in clear and comprehensive fault trees which are easily interpreted by drainage authorities.
A combination of expert judgement, qualitative fieldwork and analysis of newspapers was used to obtain an overview of all failure mechanisms and presented in the form of a fault tree. To investigate the potential damage that could be done by each failure mechanism, a probabilistic risk assessment was done using the urban drainage modelling software PCSWMM, and the potential risk of each mechanism was quantified. For the mechanisms with an unacceptably high risk, potential solutions were proposed. Four failure mechanisms were found that pose an unacceptably high risk on the drainage system: increased catchment size, pipeline blockage, inaccessible drains, and design inaccuracies. Potential solutions are to incorporate Low Impact Development (LID) in the urban area such as green and blue roofs, infiltration trenches and rain barrels. This type of infrastructure reduces the hydraulic load on the drainage system by reducing the runoff peak. In this way, urbanisation goes hand in hand
with preserving the natural flows. Other recommended solutions are to revise the cleaning schedule to make it more efficient, and raise awareness among local inhabitants to enlarge their role in the functioning of Hanoi’s drainage system.","urban flooding; Hanoi; probabilistic risk assessment; fault tree analysis; PCSWMM; integrated 1D-2D modelling; LID","en","master thesis","","","","","","","","","","","","Civil Engineering","","21.028511, 105.804817"
"uuid:329d6116-35ef-453d-a2e8-874ce6a99337","http://resolver.tudelft.nl/uuid:329d6116-35ef-453d-a2e8-874ce6a99337","Investigating fair rankers under the expected exposure framework","Visser, Maaike (TU Delft Electrical Engineering, Mathematics and Computer Science)","Hauff, C. (mentor); Chen, Lydia Y. (graduation committee); Delft University of Technology (degree granting institution)","2022","As the amount of information available in the world grows, Information Retrieval (IR) systems have become an integral part of day to day life. They determine what subset of the large pool of information is shown to people. IR algorithms determine which items should be returned in response to a query and rank the results in a ranked list.
Recently, concerns about the fairness of IR algorithms have surfaced. In particular, research is being done into whether IR algorithms are fair to producers, people or organizations that provide the items that are retrieved by IR algorithms. The higher an item is in the ranked list, the more attention it receives from users. This attention translates to benefits for the producers, e.g. fame or financial compensation.
In this thesis we investigate the fairness of IR algorithms in terms of a specific measure for provider fairness: the Expected Exposure Loss (EEL). This measure measures whether the providers of equally relevant items receive the same amount of attention in expectation. EEL was first proposed as part of the 2020 TREC Fair Ranking track (FAIR-TREC), which also provided a matching dataset. We investigate for two IR systems whether they achieve fairness on this dataset. We conduct a failure analysis and propose improvements for both systems.
We find that for a system that always returns the same ranking it is not useful to improve its accuracy, but rather that it benefits most from fairness-aware post-processing. By contrast, a fairness-aware systems does benefit from a higher accuracy, since EEL requires that equally relevant items are treated the same. We note that the generalizability of our investigation is limited due to the small size of the FAIR-TREC 2020 dataset and recommend that a larger dataset be made available.","information retrieval; fairness; expected exposure","en","master thesis","","","","","","https://github.com/pilmus/thesis Repository for reproduction purposes.","","","","","","Computer Science | Data Science and Technology","",""
"uuid:8ea9ad6b-0418-4b30-ba5c-c77b5f59aeaf","http://resolver.tudelft.nl/uuid:8ea9ad6b-0418-4b30-ba5c-c77b5f59aeaf","An Independent, Generic, User-Commanded, Sequential Quadratic Programming Module for Solving the Aircraft Trim Problem","Visser, michael (TU Delft Aerospace Engineering)","Stroosma, O. (graduation committee); van Paassen, M.M. (mentor); Delft University of Technology (degree granting institution)","2022","The Delft University of Technology (’TU Delft’) developed a real-time distributed system for scientific and educational purposes. Because of the high level of expertise required to learn from- and work in a real-time environment, TU Delft created a middleware layer, DUECA (Delft University Environment for Communication and Activation), and a simulation-specific addition framework: DUSIME (Delft University SIMulation Environment). A common practice is embedding the numerical optimization tool in an aircraft model and retrieving the starting conditions, referred to as the initial trim set. Setting up such an embedded tool for every aircraft model is very labor-intensive. For over 20 years, these issues have limited the overall user experience in DUECA. Hence, the research created an independent, generic, User-commanded, Sequential Quadratic Program (SQP) module capable of solving the aircraft trim problem in DUECA. The trim module works by a user selecting a desired steady-state aircraft trajectory through a Graphic User Interface (GUI) and then commands the trim module to search for the set of initial trim conditions. The advised flight trajectory found so far by minimizing the DASMAT trim problem are the straight-and-level descending, pull-up, and turning flight. The calculated initial trim sets allow the starting up of an aircraft simulation in a steady-state, stable enough such that a pilot can take over manual control.","","en","master thesis","","","","","","","","","","","","Aerospace Engineering","",""
"uuid:0dc6e290-1a30-42e0-bd37-5d3dc6db95db","http://resolver.tudelft.nl/uuid:0dc6e290-1a30-42e0-bd37-5d3dc6db95db","UniformGAN: generative adversarial networks in uniform probability spaces: Improving correlation by leveraging integral probability transform","Visser, Marc (TU Delft Electrical Engineering, Mathematics and Computer Science)","Chen, Lydia Y. (mentor); Zhao, Z. (mentor); Langendoen, K.G. (graduation committee); Delft University of Technology (degree granting institution)","2022","Sharing data is becoming increasingly difficult, due to the regulatory constraints imposed by the General Data Protection Regulation (GDPR). Businesses are not allowed to share data which contains privacy sensitive information. Synthetic data generation has emerged as a solution to this problem. State of the art generative adversarial networks (GAN) can generate synthetic data which statistically resembles the original data, while changing privacy sensitive information so that it cannot be related back to a person.
However, the process of generating synthetic data is still a very time consuming process for data scientists.
One of the challenges faced in synthetic data generation is aptly modeling the raw data; transforming it into numerical, and specifying the hyper-parameters such as which columns are categorical, mixed type, numerical or log distributed, is a non-trivial task. Another challenge is making estimations about the underlying distributions of the data and how these different distributions are correlated.
The proposed solution UniformGAN addresses these issues by adopting a transformer which can handle raw data and detect the data type and transforms it into a numerical equivalent. It uses the data type and estimated distribution to set the hyper-parameters for categorical columns, mixed columns, and log columns.
Furthermore, it estimates the underlying distributions of the data and leverages a statistical transformation in order for the machine learning model to easier learn the dependence structure of variables.
The evaluation with regard to machine learning utility, statistical similarity, and privacy preverabiliy has shown that UniformGAN improves accuracy with regard to decision tree classification utility, improving averaged machine learning utility by 2% compared to CTAB-GAN, and 19.21% compared to copulaGAN, while maintaining statistical similarity and privacy preservability compared to state of the art tabular data modeling techniques.","neural networks; distribution functions; GAN","en","bachelor thesis","","","","","","","","","","","","Computer Science and Engineering","CSE3000 Research Project",""
"uuid:7e7e96da-91b1-4bdb-b7d6-7b1fefd5c462","http://resolver.tudelft.nl/uuid:7e7e96da-91b1-4bdb-b7d6-7b1fefd5c462","From the seashore to the stratosphere: A step closer to continuous lung monitoring using wearable ultrasound: Lung sliding quantification","Visser, Jeffrey (TU Delft Mechanical, Maritime and Materials Engineering)","van Westerloo, D. (mentor); Lopez Matta, J.E. (mentor); Pham, H. (graduation committee); de Jonge, E. (graduation committee); Elzo Kraemer, C. (mentor); Dekker, R. (graduation committee); Delft University of Technology (degree granting institution); Universiteit Leiden (degree granting institution); Erasmus Universiteit Rotterdam (degree granting institution)","2022","b>Background: The prevention of ventilator-induced lung injury (VILI) is an important topic in criticalcare. Lung overdistention is a great attributor to VILI. Regional evaluation of the pulmonary mechanicsis a relatively new method and is currently being studied using electrical impedance tomography (EIT)and computed tomography (CT). However, ultrasonography may be an effective alternative tomeasure lung overdistention by quantifying lung sliding.
Objective: The primary aim of this study was to explore if lung sliding can be quantified using in-housemade speckle tracking algorithms. Second, the usability of lung sliding quantification to detect lungoverdistention was investigated.
Methods: Two speckle tracking algorithms were built and validated to quantify lung sliding. Adultpatients admitted to the ICU were prospectively examined using ultrasound. Ultrasound images wereanalyzed offline using the in-house developed Fourier-Based Speckle Tracking algorithm (FBST) andthe Intensity-Based Speckle Tracking algorithm (IBST). The performance of the best algorithm wasvalidated against the manual evaluation of lung sliding by experts and validated against lungcompliance. Besides, the performance of the best algorithm was investigated by reproducibilitytesting. Finally, we tested the algorithm for its ability to detect lung overdistention.
Results: The FBST algorithm could not reliably quantify lung sliding and was not further evaluated.However, the IBST algorithm showed an overall success rate of 88%. Moreover, the IBST algorithmdifferentiated normal and moderate lung sliding with a mean IBST score of 12.1 and 29, respectively(p<0.001). A positive correlation was measured between IBST score and lung compliance (β 0.15, SE0.025, 95% CI 0.101-0.208, p <0.001). The reproducibility test calculated a relative standard error of2.7. Finally, a difference was found in IBST scores between patients with a PEEP value <12 and ≥12with a mean ± SD of 20.9 ± 7 and 12.6 ± 6, p < 0.05, respectively.
Conclusion: The IBST algorithm enables a robust lung sliding quantification. The IBST scores correlatewell with expert opinion and lung compliance, but the reliability needs improvement. Our results showthat detection of lung overdistention using ultrasound is feasible. Further clinical studies should assessif ultrasonography can measure lung overdistention.","Lung; Monitoring; ARDS; Wearables; Ultrasound; COVID-19; Lung sliding; Quantification","en","master thesis","","","","","","","","","","","","Technical Medicine","",""
"uuid:63e34cba-d4c7-4387-b21b-138c035e6f99","http://resolver.tudelft.nl/uuid:63e34cba-d4c7-4387-b21b-138c035e6f99","A new social way of living in building design","Visser, Janneke (TU Delft Architecture and the Built Environment)","de Wit, L.M.M. (mentor); Speksnijder, F.J. (graduation committee); Reinders, L.G.A.J. (graduation committee); Delft University of Technology (degree granting institution)","2021","Often, the current housing stock does not address problems of social isolation at this moment in time. For example, dwellings are designed as interior spaces and the route towards the home is often an unpleasant and boring one. It is important for architects and designers to have positive impulses and guidelines to address these problems. To find these kind of guidelines, I started my graduation at the Explore Lab studio at the TU Delft with a research. Parallel to a literary study, I researched people, their social relations, space, objects and architecture through observational studies relating to social sciences (short-term ethnography, qualitative fieldwork inquiry, praxeology). I found patterns in elements relating to social relations which enabled the drafting of design principles. Through the design of a programmatic hybrid city building in Rotterdam, challenges of social isolation were explored and addressed across scales. Not only the space in and around the home, also the workspace in or outside the home is important to consider within this problematic. In the design proposal, social relations are considered in for example the route through the building, sightlines between spaces within the building, in the program, and in the didactics and details of the facade.","Social relations; Social isolation; Interdisciplinary research; Dwelling design; Home; Workspace; City building","en","master thesis","","","","","","","","","","","","Architecture, Urbanism and Building Sciences","",""
"uuid:b08f752a-42c8-4343-b784-850f15d16e45","http://resolver.tudelft.nl/uuid:b08f752a-42c8-4343-b784-850f15d16e45","The Plug-in Hybrid Electric Superyacht: An operational data-driven design","Visser, Bobby (TU Delft Mechanical, Maritime and Materials Engineering)","Hopman, J.J. (mentor); Jongepier, Bram (mentor); Kana, A.A. (graduation committee); de Vos, P. (graduation committee); Delft University of Technology (degree granting institution)","2021","This study aims to provide a proof of concept of a plug-in hybrid electric superyacht. In this way, the yachting industry can help reduce carbon emissions worldwide and potentially increase comfort levels. The concept takes advantage of the typical operating profile of a yacht. A statistical analysis is performed to discretise this and obtain parameters for the all-electric design range at design speed. The available shore power is examined by means of a questionnaire. Three options to compensate the battery weight are presented to minimise impact on design. The resulting concept versions are checked for their potential impacts on four aspects: Design, Sustainability, Comfort and Operation. This includes a life-cycle assessment that results in serious impacts on sustainability at an all-electric range of 2% to 3% of the full range capability. Finally, the concept is tested by means of a test cruise.","Sustainability; Superyacht; hybrid-electric; Plug-in electric; Data-driven design","en","master thesis","","","","","","","","","","","","Marine Technology","",""
"uuid:af85b235-2afb-47cb-b942-1d4cbc5e7a75","http://resolver.tudelft.nl/uuid:af85b235-2afb-47cb-b942-1d4cbc5e7a75","A future-proof food box: Making sustainable consumption choices easier with design","Visser, Arwin (TU Delft Industrial Design Engineering)","Schoormans, J.P.L. (mentor); Buijs, M.J.J. (graduation committee); Delft University of Technology (degree granting institution)","2021","Our food system has a huge impact on the environment and is one of the largest contributors to a global threat: climate change. The meat industry alone accounts for 15% of the greenhouse gas emissions. So, the solution would be eating less meat and dairy. But although the Dutch eat most meat replacers in Europe, the annual meat consumption hasn’t declined between 2005 and 2019. The growing number of vegans and vegetarians in The Netherlands show that it isn’t always willingness to eat less meat, but often it is habitual behaviour that is hard to disrupt. Teaching and preaching sustainability is proven to be ineffective, since consumers often filter out information that doesn’t result in short-term benefits and personal gain. Filtering out information is to reduce the mental load that consists of several struggles that consumers experience in the cooking process: finding inspiration, sticking to their budget and eating healthy and varied food. And even if consumers consider sustainability, it almost never has top priority. Therefore, a product or service that wants to help consumers choose to consume more sustainably should, primarily, focus on offering personal value and short-term benefits. In addition, sustainability has to be subtly incorporated, but never be the main attribute of the product. Consumers are already looking for help with their struggles in the cooking process, like finding inspiration Consumers are already looking for help with their struggles in the cooking process, like finding inspiration and help online and buying products that make cooking simpler and more convenient, like food boxes. But, research shows that consumers quit their food box subscription, because it is too expensive and they have no control over the size, quality and price of the vegetables. Furthermore, the recipe and herbs/sauce of the food box are considered more valuable than the vegetables. Therefore, the product that is developed in this project is a food box without vegetables. Instead, consumers receive a recipe, for inspiration and including a shopping list, and a ready-to-use sauce made of natural herbs and ingredients, which helps them with the most expensive and complicated part of a meal. All recipes are vegetarian, which nudges sustainable consumption, without compromising on price and convenience. Vegetables can be purchased in the local supermarket or local market. This increases the physical barrier compared to regular food boxes, but gives the consumer a lot of flexibility in return. The focus of the solution is to reduce the mental load for the consumer by making eating less meat easier, not more complicated. The target group are generation Y and Z, because these generations are already most sustainable, like cooking and they live online, which make it easier to target them.","food; sustainability; Product design","en","master thesis","","","","","","http://www.meetgoodcase.nl/foodbox","","","","","","Integrated Product Design","",""
"uuid:90e93658-826b-4e66-a82f-0609f26f3898","http://resolver.tudelft.nl/uuid:90e93658-826b-4e66-a82f-0609f26f3898","Forecasting elections based on the aggregation of election polls","Visser, Romée (TU Delft Electrical Engineering, Mathematics and Computer Science)","Nane, G.F. (mentor); van den Dries, B. (graduation committee); Delft University of Technology (degree granting institution)","2021","br/>Elections polls have been known to exist since 1824 [14], to fulfill the objective of what is happening and may happen. In this thesis it is investigated what the performance of election polls is and if the aggregation of polls give a better forecast than the polls themselves. The data is used of Spain during years 2012 until 2017 and The Netherlands during years 2010 until 2021. Furthermore, in this thesis the results of Spain and The Netherlands are compared. The aggregation of polls is done by using The Classical Model of Roger Cooke [2] and by using two types of Equal weighting. When using the Classical Model two different methods are used, namely a window-shift way and a cumulative way. The comparison between the aggregation of polls and the polls themselves is done by looking at the unnormalized weights and the total absolute differences. The results were quite different for the two countries. However, for both countries it appeared that method 1 was better when looking at the unnormalized weights, while method 2 was better when considering the total absolute differences. When looking at the unnormalized weights for the Spanish data the forecast when aggregating the polls, using the Item weight decision maker, was better than most of the polls’ forecasts. In addition when looking at the absolute total differences of the Spanish data, the forecast when aggregating the polls, also using the Item weight decision maker, was better than most of the polls’ forecasts. Similarly for the Dutch data when looking at the unnormalized weights, the forecast of the election when aggregating the polls, using the Performance-based decision maker, was better than most of the polls’ forecasts. In addition, when looking at the total absolute differences, the aggregation using the Equal weight decision maker based on distribution was better than most of the polls’ forecasts.","Decision theory; Classical Model; Aggregation","en","bachelor thesis","","","","","","","","","","","","","",""
"uuid:76d6fcf7-3ef5-4f4c-99e4-c04b29b1468d","http://resolver.tudelft.nl/uuid:76d6fcf7-3ef5-4f4c-99e4-c04b29b1468d","A Techno-Economical Analysis of Hydrogen as Long-Term Storage Medium in the Netherlands: How long-term hydrogen storage helps to achieve energy security in an energy system dominated by variable renewable energy sources","Visser, Julian (TU Delft Electrical Engineering, Mathematics and Computer Science)","van der Blij, N.H. (mentor); Delft University of Technology (degree granting institution)","2021","The integration of Variable Renewable Energy Sources (VRES) creates challenges for meeting load demand. The lack of on-demand power generation of these VRES effectively threatens energy security. Therefore, storage facilities, especially hydrogen, have been broadly researched for potential implementation in our energy system, enabling on-demand power ""generation"". This thesis adds to this research by providing a framework on how VRES and long-term storage technologies can be most optimally utilized to ensure weekly or monthly energy security. This framework is explicitly applied to the Netherlands and reviews the opportunities of a VRES dominated future energy system. The framework consists of a VRES generation model and load model and identifies the optimal load coverage using single- and multi-objective genetic algorithms. The VRES generation model is designed for a weekly and monthly timeframe by using 31 years of available weather data (1988-2018), specifically average wind speeds and solar irradiance, for a number of locations in the Netherlands. Using the available weather data, power generation per MW of onshore wind, offshore wind, and solar PV are calculated. Subsequently, this calculated VRES power generation is compared to available real-world VRES power generation data and a correction factor is determined. Applying the correction factor to the more extensive weather data set allows to effectively create a VRES power generation model, based on the weather circumstances as in these 31 years. Additionally, a weekly and monthly 31-year load profile is determined, using available data for load demand in the Netherlands. Thereafter, both a single and multi-objective algorithm is tasked to provide load coverage in two main scenarios at minimum cost. First, load coverage is achieved exclusively utilizing VRES capacity. Secondly, a variety of long-term storage facilities are introduced in combination with VRES capacity to acquire energy security. Furthermore, these two methods for achieving energy security are restricted in a number of sub-scenarios, which represent the societal preference restrictions regarding VRES installations.
Generally, energy security is most cost-effectively achieved utilizing long-term hydrogen storage facilities, as compared to an exclusive VRES approach. Specifically, alkaline electrolysis and hydrogen combined cycle gas turbines seem to be the most promising technologies to be applied for the hydrogen storage facility electrolysis and reconversion sub-steps respectively. Furthermore, societal preference has a significant effect on the total costs, increasing it considerably when offshore wind capacity is forcefully introduced in the VRES capacity mixture. Lastly, the timeframe considered for achieving energy security, either weekly or monthly, has a substantial effect on the total cost. The smaller weekly timeframe results in additional costs, as the long-term hydrogen storage facility, is utilized more broadly to meet load demand, increasing the capacity requirements for charging, discharging, and storage. Overall costs range between 139 and 211 billion Euros to achieve energy security using the more cost-effective long-term hydrogen storage approach, depending on the timeframe and societal constraints applied.
In a within-subject driving simulator study, thirty-two participants drove under five conditions: no enhancement (Off), PTE, ESE, PTE and ESE combined (PTE-ESE) and a control condition (Control) with a physically sportier car (i.e., more engine power and a sports car sound). PTE provided a more sensitive pedal-to-throttle mapping and ESE an engine sound associated with increased engine speed. Both implementations did not increase engine power. Perceived sportiness was measured using a questionnaire, whereas driving behaviour was retrieved from the simulator.
The results showed that ESE contributed significantly to perceived sportiness and perceived engine responsiveness, whereas PTE had no to limited effect. Furthermore, ESE created the impression of enhanced engine responsiveness, more so than PTE. PTE resulted in increased acceleration during acceleration from standstill, whereas driving behaviour was not significantly affected by ESE compared to Off. In addition, PTE significantly influenced control behaviour: it led to a decreased mean accelerator pedal depression angle and an increased mean throttle reversal rate compare to Off.
We conclude that ESE increases perceived sportiness to the extent it approaches the perceived sportiness of an actual sportier car without altering the driving behaviour or decreasing safety margins. The findings of this study support the use of ESE in sport mode. PTE should be further explored in an experimental setup that provides vestibular feedback.","perceived sportiness; engine sound enhancement; power-train enhancement; driving simulator","en","master thesis","","","","","","","","","","","","Mechanical Engineering","",""
"uuid:ac19345f-0f16-466e-8e80-4b6f16acbe6b","http://resolver.tudelft.nl/uuid:ac19345f-0f16-466e-8e80-4b6f16acbe6b","The debugger as a learning tool for object-oriented programming","Visser, John (TU Delft Electrical Engineering, Mathematics and Computer Science)","Zaidman, A.E. (mentor); Delft University of Technology (degree granting institution)","2021","Novice students still have problems with the abstraction of object-oriented programming. This research shows that the debugger could be used to clarify abstraction of the object-oriented programming with the C++ program language. Our investigation spans two consecutive courses on object-oriented programming. For the introduction course on the object-oriented programming, we modified both lectures and lab sessions so that with the help of the debugger objects could be visualised, and we could walk through the program step by step. In the second course, the lectures were extended by forty-five minutes, allowing the students to do assignments during the lectures with the help of the debugger. The results of the written examination and the completed questionnaire showed that working with the debugger in both the lectures and the practical exercises had a positive influence, especially for the introductory course on object-oriented programming. Although the Corona pandemic influenced part two, the results of the written exam did improve, but it is unclear which influence the use of the debugger had during this course. Visualising objects and walking through methods step by step could help in understanding the fundamentals of object-oriented programming language C++.","debugger; Object-Oriented Programming; education","en","master thesis","","","","","","","","","","","","Computer Science","","52.0017011, 4.3678927"
"uuid:3ff92e66-7e7f-4b76-8aa2-a4d95e2d2e4a","http://resolver.tudelft.nl/uuid:3ff92e66-7e7f-4b76-8aa2-a4d95e2d2e4a","The (mis)alignment of user involvement with development objectives: An exploration of the alignment of private-led user involvement with the objectives of the private developer, municipality and users in urban renewal projects","Visser, Dana (TU Delft Architecture and the Built Environment)","Czischke, D.K. (mentor); Janssen, C. (mentor); Delft University of Technology (degree granting institution)","2021","Urban renewal is seen as an opportunity to improve the environmental and socio-economic performance of cities. Yet, it appears hard to tackle the social challenges by a focus on spatial interventions only. A more participating society and more user involvement could help to improve the social environment. Dutch urban area development, such as urban renewal, is becoming more private-led, while the government is trying to shift responsibilities. The Environment and Planning Act is a tool to ensure the involvement of users during private-led developments. In theory, an involvement process can contribute to the objectives of the most important stakeholders in urban renewal projects: the government, users and private developers. Since these potentials in practice are often not achieved, literature advises to involve users early and intensively in the development process and to develop with flexibility along the process. However, for each project, boundaries limit the development options for a private developer and therefore, as well the options to involve users. It seems that private developers do not have enough room for involvement to align the involvement process with the objectives of the three stakeholders. This study explores that hypothesis. Considering the perspective of the private developer, the main question of this research is: to what extent do the development boundaries leave enough room for private developers to align user involvement with the objectives of users, the municipality and the developer themselves? The research is conducted through a case study analysis of three private-led urban renewal projects in which users were involved. Developers, municipal officials and users were interviewed to gain insights. The analyses show how development boundaries are defined, what room is left for user involvement and how the involvement process aligns with the objectives of the three parties. By considering the developers perspective, it is explored why the current involvement processes are not reaching their full potential as described in theory. This study shows that full alignment is difficult due to conflicting demands. Municipal broader, cross border objectives often conflict with those of the local users. It appears that the boundaries defined by the municipality are quite fixed, while those of the developers are flexible. This flexibility could be used when there is a lack of support for the plans. Since full alignment seems impossible, a second interview round provides insights into what extend of alignment would be important for private developers to aim for. For developers, long term business continuity and a positive corporate image are important to ensure profit gaining in the future. For them, this is more important than profit gaining in the short term. Flexibility can be found in the development boundaries when these long term objectives seem to be threatened. Game theory, approaching user involvement as a negotiation process and integral development offer opportunities for private developers to improve the alignment of everyone’s objectives with user involvement without having to adjust their development boundaries, unplanned. This will need to be further explored in new research. The insights from this study provide knowledge about the relation between the important stakeholders in urban renewal projects and how they influence a user involvement process. This new knowledge can help to reach more potentials of user involvement in practice.","Urban renewal; Social city performances; User involvement; Private-led development; Development boundaries; Alignment of objectives; Environment and planning act","en","master thesis","","","","","","","","","","","","","",""
"uuid:84f14de1-74d7-48c5-a5f9-a83a8c9482c4","http://resolver.tudelft.nl/uuid:84f14de1-74d7-48c5-a5f9-a83a8c9482c4","Seasonal Hydrogen Storage in Dutch Depleted Gas Reservoirs: A Feasibility Study for The Netherlands","Visser, Thomas (TU Delft Civil Engineering and Geosciences)","Hajibeygi, H. (mentor); Delft University of Technology (degree granting institution)","2020","The Netherlands will need to transform her traditionally fossil fueled energy system in the coming decades to achieve the goal of reducing CO2 emissions to net-zero in 2050. Therefore, an increase in renewable energy sources as solar and wind energy in the overall energy mix will be essential. However, due to the highly variable energy production patterns of these renewable energy sources, a primary need for energy storage is created. Since electricity can not be stored on a large enough scale to balance significant energy fluctuations, the need for a gaseous CO2 neutral energy carrier is created. In The Netherlands, this role could potentially be fulfilled by green hydrogen gas. Green hydrogen can be stored in geological formations such as depleted gas reservoirs. Due to the immense storage volumes and frequent occurrence in the Dutch subsurface, depleted gas reservoirs could be an excellent opportunity to serve as large scale energy storage sites. Moreover, underground natural gas storage in gas reservoirs is a proven and used technique in The Netherlands. Utilizing a natural gas reservoir as a hydrogen storage site comes with several challenges. This report provides a full overview of all the challenges with underground hydrogen storage in geological formations as aquifers, depleted gas reservoirs and salt caverns based on literature. In this way, the full potential and risks of using depleted gas reservoirs for this technique is clearly highlighted. Using this overview, a priority scheme for the usage of different geological formations as storage facilities for hydrogen is proposed. In combination with possible meteorological conditions combined with different Dutch policy scenarios, a minimum seasonal storage need of 16 TWh through the use of hydrogen is identified. Using the priority scheme, rock salt caverns are used as much as possible to fulfill the minimal need for seasonal hydrogen storage. By performing an analysis on the potential subsurface storage capacity in The Netherlands, it becomes clear that the Dutch subsurface can not realize more than 12.1 TWh of potential hydrogen storage capacity by only utilizing salt caverns. Since depleted gas reservoirs are identified as the best alternative for underground hydrogen storage, a minimum need for hydrogen storage from Dutch depleted gas reservoirs is estimated at 3.9 TWh in 2050. In this thesis, all physical and chemical aspects that are important during the subsurface storage of hydrogen in porous media are addressed. This leads to the identification of potential losses of hydrogen during the storage of the gas in the depleted gas reservoir. Analyzing all the possible methods leading to potential hydrogen loss shows that on the long term, bacterial conversion seems to be the biggest challenge if no measures against this conversion are taken. Using numerical reservoir simulation as a quantification and sensitivity analysis tool, the hydrodynamic behaviour of hydrogen in contact with other gasses is described. This is done by introducing a dimensionless gravity number. The interpretation of this number shows if the displacement process is either dominated by viscous or gravitational forces. Furthermore, the displacement efficiency of hydrogen towards other gasses is analyzed. Displacement of hydrogen towards residual gasses in porous media dominated by viscous forces proves to be more efficient than the displacement dominated by gravitational forces. By performing cyclic storage simulations, the overall efficiency of injecting and reproducing hydrogen from a depleted gas reservoir is examined. This is done for both homogeneous and heterogeneous reservoirs. By performing a sensitivity analysis on the input parameters of the simulator, an overview is given of the parameters that will have the most positive or negative impact on the cycle efficiency. The results of the simulation show a regular cycle efficiency that is estimated at roughly 70%. Applying a higher difference in injection and production pressure leads to a lower cycle efficiency whereas using a more elongate reservoir as storage site shows to have a positive effect on the overall cyclic efficiency.","Hydrogen; Storage; Depleted gas reservoir; Gravity Number; Reservoir Simulation; The Netherlands; Seasonal storage; Feasibility Study","en","master thesis","","","","","","","","","","","","Petroleum Engineering and Geo-sciences","",""
"uuid:8820b395-c64b-4a5d-87a4-fbf7d1b17a6c","http://resolver.tudelft.nl/uuid:8820b395-c64b-4a5d-87a4-fbf7d1b17a6c","A cup deposit system: An implementation strategy for NS stations to engage customers to use reusable cups and lower their environmental impact","Visser, J.S. (TU Delft Industrial Design Engineering)","Schuffelers, R.J.G. (mentor); Balkenende, A.R. (mentor); van den Berg, E.K. (mentor); Delft University of Technology (degree granting institution)","2020","This graduation project focused on lowering the environmental impact in which warm beverages were drunk at NS stations by motivating user to use reusable cups. It was explored why customers currently do not use reusable cups at NS stations, which solution space can be used to motivate customers to use a reusable cup and how NS can implement this solution space in the NS context.
Different research activities were conducted to under why customers are not using reusable cups now and how NS can motivate thee users. By analysing the results from observations, user interviews and context mapping. Based on the findings 5 barriers were found why customers are not using reusable cups.
Next to these insights 4 personas were created and it was also found how NS can improve the customer experience of drinking a warm beverage at their stations.
Based on these insights two solutions spaces where formulated which were compared to the paper cup. It was concluded that the deposit cup system would be the best reusable cup system for under the right circumstances, but that a user owned cup and a paper cup still have their place.
Because there is no cup deposit system that fits the needs of NS stations the following design goal was formulated:
Design a cup deposit system that has a return rate of at least 98.5% and motivates customers that buy a warm beverage at NS stations to use a reusable cup instead of a single use paper cup, by taking their drivers into account, while at the same time fitting inside the constraints of the NS retail system. This will lower the environmental impact of cups for warm beverages sold at NS stations.
Next to the design goal a design vision was formulated to illustrate how customers should feel when these the system taking each persona into account.
Based on the design goal and the design vision multiple concepts were created from which one was chosen and further detailed into a final concept. This final concept was evaluated with experts within NS, see figure FIX ME. To implement the final concept a road map was made.","Sustainabilty; Contextmapping; Cup deposit system; Nederlandse Spoorwegen","en","master thesis","","","","","","","","","","","","Design for Interaction","",""
"uuid:e7bb26fe-da1a-4dd0-a0e8-da017c190730","http://resolver.tudelft.nl/uuid:e7bb26fe-da1a-4dd0-a0e8-da017c190730","Exploring the value-stacking opportunities of batteries providing frequency containment reserve services in different regulatory environments","Visser, Jelle (TU Delft Technology, Policy and Management)","Heijnen, P.W. (mentor); Warnier, Martijn (mentor); Okur, Ö. (graduation committee); Delft University of Technology (degree granting institution)","2020","The security and reliability of the European power system network that is used to transmit electricity from producers to consumers is under increasing pressure. The penetration of renewable energy resources that have a variable and unpredictable energy output and the rising cost of the operation of fossil-based power generators are negatively influencing the availability of controlling power that is critical for normal system functioning. Without this controlling power, there is a risk of electricity network imbalances and complete electricity blackouts. To be able to guarantee the continuity of electricity supply, transmission system operators are required to search for new and alternative flexibility resources, including resources that could provide the primary system response (frequency containment reserve) to these grid imbalances. Battery energy storage systems are one of the most promising alternative resources that could provide this load controlling capacity. These systems are, however, extremely cost-intensive. Using a battery for multiple battery applications simultaneously could improve the financial viability of these battery energy storage systems and thereby, accelerate their deployment in society. To be able to get the full potential out of this value-stacking opportunity, more insight into the technical and operational compatibility of using a battery for frequency containment reserve and other battery applications is required. In this master thesis, a research was conducted to obtain a better understanding of the opportunities to create added value in the utilization of a battery that is providing frequency containment reserve services. By means of a (multiple-)case study research (including a literature review, a simulation model and a time series analysis and forecasting model), more insight was obtained in the power and energy capacity utilization of a battery that is providing frequency containment reserve services and the usability of the leftover capacities of this battery for serving other battery applications. In the literature review that was performed, it was demonstrated that the activation of batteries for frequency containment reserve is mainly dependent upon the regulations and grid characteristics that are present in the area of interest. These regulations provide terms and conditions for the theoretical use of a battery’s power and energy capacity and therefore, the theoretical opportunities for valuestacking. These value-stacking opportunities include the use of moments in which a battery is idle and the time periods in which a battery is not using its full energy capacity. The simulation study that was performed subsequently showed that for all frequency containment reserve markets examined in this research, there are moments and periods in time in which a battery is not using its entire reserved frequency containment reserve power and energy capacity. This indicates that using a battery at these particular moments and periods in time for other battery purposes might create substantial added value to the overall system operation. The analysis of the data that was obtained from the simulation study showed that the practical usability of these moments and periods in time for value-stacking opportunities seems limited. Although it was illustrated that there are moments in which the battery’s power capacity is not used, no clear prediction can be made of these so called ‘idle moments’. Consequently, it is uncertain at what exact moments in time the battery is idle and could be used for other battery purposes. The duration of the idle moments is furthermore relatively short, which makes it difficult to use these idle time periods for applications that require consecutive power supply or energy storage. Results of the time series analysis and forecasting model demonstrated that there might be opportunities to predict the required energy capacity for frequency containment reserve. This indicates that forecasts can be made of the state of charge development of a battery over a certain time period. This information can be used to identify the underutilized battery energy capacity, which subsequently could be used for other battery applications. The combination of both the power and energy capacity limitations prove to be a challenge when aiming at value-stacking of a battery. Using the idle moments and the forecasted available energy capacity of a battery for other battery applications requires expert knowledge of the energy capacity that is needed for the additional application and seems to require flexibility of power capacity utilization of the additional application itself. Further research should focus on the improvement and validation of the frequency containment reserve activation forecasts to be able to make a better estimation of the battery energy capacity that is available for serving other battery purposes. Research should moreover be conducted to examine the energy and power requirements of other applications over time. This includes the need for state of charge control. The information that is obtained from these studies is essential to identify how various battery applications, including frequency containment reserve, can be properly aligned and could add value to the battery system operation.","","en","master thesis","","","","","","","","","","","","Complex Systems Engineering and Management (CoSEM)","",""
"uuid:29c8cc24-dc38-44f4-96da-4a26f39b57e6","http://resolver.tudelft.nl/uuid:29c8cc24-dc38-44f4-96da-4a26f39b57e6","Energy System Integration Demonstrator: Energy data widget","van Paassen, D. (TU Delft Electrical Engineering, Mathematics and Computer Science); Visser, B.E. (TU Delft Electrical Engineering, Mathematics and Computer Science)","Cvetkovic, M. (mentor); van der Meer, A.A. (graduation committee); Delft University of Technology (degree granting institution)","2020","Renewable sources are gaining more importance now than ever. As a consequence, the development and complexity of electricity grids are rising. This thesis is part of a project which aims to comprehend and package the integration of such complex grids into something more understandable such as a demonstrator tool. More precisely, how do you find a solution to model these kinds of components inside a grid to something easier and touchy? In the context of this thesis, this means that sources, loads and energy storage in today’s grids need modelling to represent their operations. Based on models in literature studies, a correct operational way of modelling is discussed and worked out. Several cases will be presented where the operation of such models is verified and presented. Experimental results show that the accuracy of these models comes very close with actual data values from manufacturers. On the basis of these results it is stated that a tool such as this thesis describes, will resemble such a transition appropriately and therefore helps for better understanding.","Energy grid; emulation; demonstrator; data widget","en","bachelor thesis","","","","","","","","","","","","","",""
"uuid:542097e8-3335-497d-ac4b-a355829c2808","http://resolver.tudelft.nl/uuid:542097e8-3335-497d-ac4b-a355829c2808","Study into the short and long term (re)production of relations between communities, inorganic solid waste and the Surabaya River, Indonesia","Visser, Swaen (TU Delft Civil Engineering and Geosciences; TU Delft Water Resources)","Ertsen, M.W. (mentor); Scholten, L. (graduation committee); Bogaard, T.A. (graduation committee); Doorn, N. (graduation committee); Pramana, K.E.R. (graduation committee); Delft University of Technology (degree granting institution)","2019","In Indonesia, river pollution due to inorganic solid waste has become an enormous issue. This article explores the (re)production of relations between communities, river and inorganic solid waste in the Surabaya River Basin. It does so by analysing activities based on interviews, observations and measurements. It tries to explain the current situation in the Surabaya River Basin and shows how ’river water’ and ’waste’ shape ontologies. Furthermore, how these two nonhuman actors act differently (or the same) in different ontologies. The definition used in this study for an ontology is ""a construction of how concepts of reality are constructed"". Several analyses are used. Firstly, statistics are used to support narratives where deemed necessary. In addition, QGIS is used to visualise data. Lastly, a flow diagram is made to show the flow of waste into the Surabaya River. Existence of multiple ontologies in the Surabaya River Basin is described. It is found that both reproduction of actions is present (on the short term) as well as production of different actions, which becomes more visible in the long term. For example, waste burning every afternoon is a reoccurring action. However, the reduction of single-use plastics is an evolved state. The riverbank is an important location in the relations and could serve as a suitable location for such actions. Lack of information, communication and facilities are identified to be the most important issues. In general, people are optimistic and motivated concerning the environment. However there are some people not engaged. This causes a divide and together with social control leads to tensions in the community. Recommendations include, among others, setting up an information sharing platform between institutions and community members and making use of the cultural resources to work towards a common goal. Including the multiple ontologies in decision-making processes could lead to inclusive and sustainable river management and waste management.","River pollution; Ontology; Surabaya River; Domestic inorganic solid waste; Community","en","master thesis","","","","","","","","","","","","Water Management","","-7.400528, 112.528167"
"uuid:3fa73fcf-044b-4f4c-b425-1e3d76acd31a","http://resolver.tudelft.nl/uuid:3fa73fcf-044b-4f4c-b425-1e3d76acd31a","Calibration of a Single element ultrasound transducer using an aberration mask","Visser, Bram (TU Delft Electrical Engineering, Mathematics and Computer Science)","Leus, Geert (mentor); Kruizinga, Pieter (graduation committee); van der Meulen, Pim (graduation committee); Delft University of Technology (degree granting institution)","2019","Previous work [1] has demonstrated the possibility of high resolution imaging through the use of a single element and a aberration mask. This thesis will expand on the previous work by examining the proposed method for errors in the creation of the model. The analysis is preformed by examining the various aspects of the measurements setup and underlying theoretical model, after which measurements are performed to determine their contribution and correctness with regard to the model. Results demonstrated a systematic error of a non-linear frequency scaling and semi-linear phase shift. The origin of the error lies in the unwanted addition of transfer functions of some of the components. A Tikhonov regularized least squares method is proposed to estimate this transfer function and supply compensation based on all the measurements. The results of application of this method on the uncalibrated model are demonstrated through 1D imaging experiments. The result of which show a signicant improvement over the previous uncalibrated results. After which the possibility of calibration due to a singular measurement is explored and a adaptation of the Tikhonov regularized least squares method is proposed for close approximation of the previously found transfer function. Further to obtain an indication of possible remaining hurdles and successes with this method, extensive simulations are preformed to examine the individual impact of various sources of noise and interference.","Calibration; Ultrasound; Single element imaging","en","master thesis","","","","","","","","","","","","","",""
"uuid:672e1f92-306e-4b71-a18d-6b59d3c5ba8d","http://resolver.tudelft.nl/uuid:672e1f92-306e-4b71-a18d-6b59d3c5ba8d","A strategy to monitor and mitigate risks associated with the plan-adaptation process at HollandPTC","Visser, Miranda (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Biomechanical Engineering)","Klein, J. (mentor); Clarijs, Jesse (graduation committee); Delft University of Technology (degree granting institution)","2019","The steep rise of advanced technology in healthcare and the required spe- cialisation of staff causes healthcare systems to have become increasingly complex. This increased complexity poses great challenges on the risk management of systems. Many different methods have been developed the past decennia to identify potential risks in these system to enhance safety. A commonly used prospective risk analysis method is HFMEA, which is based on the linear view on system safety. Another relatively new method is FRAM which meets the dynamic systemic view on safety and focusses more on potential risks in a system due to ""everyday performance"". An example of a complex healthcare system is proton therapy; a novel type of radiotherapy to treat tumours in the proximity of the central nervous system. The first operational clinic in the Netherlands providing this therapy is HollandPTC. During the therapy the tumours are irradiated with a high precision in multiple sessions. When anatomical variation is observed between these sessions, the treatment plan of a patient has to be adjusted. This critical process is called plan-adaptation and has to be both time-efficient and safe. To ensure the safety of the plan-adaptation process at HollandPTC, currently controls are designed based on potential risks identified with HFMEA.
The aim of this thesis is to identify an effective strategy to identify which controls are able to monitor and mitigate risks associated with the process of plan adaptation at HollandPTC.
Independently of the HFMEA, a FRAM was conducted on the plan-adaptation process at HollandPTC. The resulting set of potential risks were compared with the po- tential risks identified with HFMEA. Furthermore, the effectiveness of the controls proposed by HFMEA were assessed on the set of potential risks identified with FRAM. Based on these results a strategy is proposed to monitor and mitigate the potential risks.
The analysis of the FRAM models revealed among others potential risks related to: informal communication lines between caregivers, discrepancies between caregivers ideas about task division and identified multiple causes for time delays. These risks were not identified with HFMEA. The controls proposed by HFMEA do not mitigate the potential risks identified with FRAM. By combining the strengths of both HFMEA and FRAM, an effective strategy is proposed to monitor risk and to identify effective controls. This strategy can be used as a prospective risk-analysis method and on ongoing processes.","Proton therapy; FRAM; Safety","en","master thesis","","","","","","","","2021-08-22","","","","","",""
"uuid:71cb9565-2e55-4733-a96e-e8b74abfc615","http://resolver.tudelft.nl/uuid:71cb9565-2e55-4733-a96e-e8b74abfc615","Families in the city","Visser, Daphne (TU Delft Architecture and the Built Environment)","Kupers, Theo (mentor); Adema, Ferry (mentor); van der Putt, Pierijn (mentor); Delft University of Technology (degree granting institution)","2019","The number of households in Amsterdam has decreased significantly over the past few years. This trend seems to continue and may result in an unbalanced age composition within the city. The design of the apartment complex NEST 020 contributes to the preservation of families in the city.","families; city; amsterdam; housing","en","master thesis","","","","","","","","","","","","Architecture, Urbanism and Building Sciences","",""
"uuid:1152030a-ab73-4336-8f98-144024ea9db8","http://resolver.tudelft.nl/uuid:1152030a-ab73-4336-8f98-144024ea9db8","Effects of reducing extraneous water on the performance of wastewater treatment plants","Visser, Thibaut (TU Delft Civil Engineering and Geosciences)","Langeveld, Jeroen (mentor); van Lier, Jules (graduation committee); Spanjers, Henri (graduation committee); Mostert, Erik (graduation committee); van der Veen, Ron (graduation committee); Delft University of Technology (degree granting institution)","2019","Besides wastewater and rainwater, the sewers in the Netherlands also transport a lot of water that is not supposed to be in the sewer. This water is called extraneous water and is the result of unwanted discharges in the sewer system. This could be groundwater infiltrating leaky sewer pipes, or pumped from construction sites directly into the sewer. Or it could be surface water flowing in from wrong illicit connections. In the Netherlands, all this extra water account for a quarter of all the influent that enters the treatment plants.
This thesis studies the effect of a reduction of extraneous water in the influent on the workings of the treatment plant. For this two cases are studied: the treatment plant of Dokhaven in Rotterdam and Willem Annapolder in Kapelle. Dokhaven is a high loaded treatment plant with an A-B configuration that treats the wastewater from the center of Rotterdam in which it is located. Willem Annapolder is a low loaded treatment plant with biological phosphor removal and pre-denitrification and treats the wastewater from different cities and municipalities in its surroundings connected by long pressure mains. Both cases are known to receive a lot of extraneous water in their influent.
Two models were made for each case study: one that simulates the dynamics of the influent concentrations and another that describes the water treatment processes in the treatment plant. After calibration, the models of the treatment plant were run with a different influent in which the extraneous water was reduced.
Previous studies have indicated that a reduction in extraneous water leads only to small changes in the effluent concentration, but due to the reduced flow leads to significant reduction in the effluent load. In the case of Dokhaven the models show similar results. In the case of Willem Annapolder, the effects of the pressure mains was also taken into account. This caused the resulting effluent ammonia concentration to increase when extraneous water was reduced. The reduction in clean extraneous water increases the dry weather concentration of the pollutants in the pressure mains. When a rain event occurs, this water with high concentration is pushed towards the treatment plant with increased flow, which causes increased peak loads at the start of every heavy rain event.
Although the overall nitrogen load on the effluent was also decreased at Willem Annapolder when the extraneous water was reduced, the pressure mains resulted in a much lower decrease than in the case of Dokhaven. This thesis thus shows that it is important to take into account the sewer system when evaluating the effects of reducing extraneous water.","Extraneous water; wastewater treatment; sewer network; model; BioWin","en","master thesis","","","","","","","","","","","","Civil Engineering","",""
"uuid:54fce99b-0349-434f-9d52-5219d72fdc7e","http://resolver.tudelft.nl/uuid:54fce99b-0349-434f-9d52-5219d72fdc7e","Data analysis application for the ORCHID","Visser, Maaike (TU Delft Electrical Engineering, Mathematics and Computer Science); van der Heijden, Stefan (TU Delft Electrical Engineering, Mathematics and Computer Science); Mironov, Stas (TU Delft Electrical Engineering, Mathematics and Computer Science); Hullegien, Nils (TU Delft Electrical Engineering, Mathematics and Computer Science)","Head, Adam (mentor); Rellermeyer, Jan (graduation committee); Delft University of Technology (degree granting institution)","2019","The Organic Rankine Cycle Hybrid Integrated Device (ORCHID) is a small scale power plant that is used to study the fundamental gas dynamic behavior of dense organic fluids, as well as the behavior of turbomachinery. In order to draw accurate conclusions about the raw sensor data generated by the ORCHID one has to know when the system is in steady-state. Currently, determining the steady state over historical data is cumbersome, and difficult to do in real time.
Our application aims to solve the problems with the current information workflow by consolidating the functionality that is currently spread across multiple applications into one main application, as well by offering steady state detection over real-time data. Aside from the lack of steady state detection capabilities, our client indicated that the applications currently in use often lag or crash. Therefore we defined three design goals: Performance, Reliability, and Ease of Use.
The main challenge we encountered during this phase was finding a way to properly connect the different external applications needed to properly process the ORCHID's data. The design goals were continuously referenced during the implementation phase to ensure the quality of our application. Additionally, we used unit, integration, and manual testing. The last category also comprised user tests conducted with our client to ensure that the final product would meet his requirements.
With our final application, we solve the client's main problem: it is now possible to detect whether or not a system is in steady state while an experiment is being conducted. This greatly reduces both the amount of time the client has to invest, as well as the amount of energy needed to conduct a successful experiment.","data processing; data visualization; graphical user interface; external components","en","bachelor thesis","","","","","","","","","","","","","",""
"uuid:3ca2d0d4-d275-46fd-b8db-3f66ebef53a2","http://resolver.tudelft.nl/uuid:3ca2d0d4-d275-46fd-b8db-3f66ebef53a2","Discrete Frequency Seismology","Visser, Adriaan (TU Delft Applied Sciences; TU Delft Civil Engineering and Geosciences)","Hanssen, Ramon (mentor); Verschuur, D.J. (graduation committee); Dheenathayalan, Prabu (graduation committee); Blacquière, Gerrit (graduation committee); Kalkman, Jeroen (graduation committee); Delft University of Technology (degree granting institution)","2018","This work determines whether the amount of frequency components present in the data can be reduced, whilst still retaining image quality, whereas most efforts in seismological research are done in reducing spatial sampling. It is shown using a PCA on the frequency spectra of several data sets that indeed a large redundancy in frequency content is present in onshore seismic data, and an attempt is made to generate a distribution of frequencies in order of importance. Given this redundancy in the frequency spectrum of onshore seismic data, it has been attempted to reconstruct the missing frequencies by applying the Fourier transformation iteratively to the data. However, this transform does not take spatial sampling into account, which is aimed at to compensate for the missing frequencies. Therefore it has been elected to use a linear Radon transformation instead, which keeps components which are connected in space-time connected in the transform domain. A CGNE scheme has been set up to reconstruct the data, which performs very well along the almost linear asymptots in the shot records, up to a reduction of 70% of frequency components. This scheme iteratively applies the linear Radon transform to a shot record, weighing the data in the transform domain with an amplitude based norm. The energy that was spread out due to aliasing because of the missing frequencies is refocused to the main reflectors, especially along the asymptots of the reflection hyperbola. Missing frequencies are reconstructed, up to a scaling factor, and band gaps of up to 6Hz get filled in very well. Next, it is attempted in this work to give quantitative quality metrics, to make comparison between seismic images easier and based on data, rather than subjective visual inspection. Treating migration as a black box, several quality metrics have been devised for the migrated sections: correlation to the ground truth, contrast within an image, average length of found lines, and local SNR. Contrast is not a very good metric to compare between images as its average across an image is almost constant with reduction percentage. The other parameters are good metrics and show a clear trend that the fewer frequency components present in the shot records, the worse the quality of the final image. An increase in deterioration of image quality is observed around 70% reduction, which is in correspondence with the earlier found value for the shot records.","Seismology; Frequency; Sparse inversion; Radon","en","master thesis","","","","","","","","","","","","Applied Earth Sciences","",""
"uuid:719c107b-67a2-497d-991a-a70b0cb992aa","http://resolver.tudelft.nl/uuid:719c107b-67a2-497d-991a-a70b0cb992aa","Creating a simplified and standardised bioreactor system for tissue-engineered vascular graft culturing and characterisation","Visser, Dmitri (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Biomechanical Engineering; TU Delft Biomaterials & Tissue Biomechanics)","Hinderer, Svenja (mentor); Fratila-Apachitei, Lidy (mentor); Zadpoor, Amir (graduation committee); Kenjeres, Sasa (graduation committee); Delft University of Technology (degree granting institution)","2018","With the recent developments in tissue-engineered organ substitutes, there has been an increasing demand for novel culturing techniques to create biological substitutes in vitro, as well as reliable and efficient test methods that can assess their biocompatibility and mechanical performance. In the past two decades, perfusion bioreactors have proved to be important tools in the creation, control, and evaluation of cell cultures and engineered tissues under precisely controlled in vitro conditions that simulate the physiological environment. Due to the demanding requirements for blood vessel substitutes, they have been extensively deployed in the culture and conditioning experiments of novel tissue-engineered vascular grafts (TEVGs) and have been often used to study haemodynamic mechanic stimuli, including the cyclic vessel expansion and wall shear stress. However, a key limitation of the currently available TEVG perfusion bioreactors is their often complex design and operation and the lack of standardisation of the mechanical characterisation.
In this study, the goal was to design, characterise, and construct a TEVG perfusion bioreactor that is foremost simpler to operate and extends the capabilities of particular currently available set-ups. A modular bioreactor design is presented that allows for the toolless mounting of the graft with a diameter up to 6 mm and features completely separated circuits for the intra- and extraluminal side of the scaffold wall. The culture chamber encloses a removable graft frame, mainly machined out of polyether ether ketone (PEEK). In silico simulations have been used to assess local fluid dynamics within the scaffold, to predict the reliability of the simulated culture conditions. The presented design allows the exertion of a broad range of physiologically relevant shear stresses on cultured TEVGs, including arterial shear stresses. A test for the in vitro cytotoxicity showed that the medium extracts of the constructed graft frame did not show any cytotoxic potential. Finally, an assessment method for the estimation of the radial compliance is proposed, which aims to adhere to the relevant international standards on the mechanical characterisation of vascular substitutes.","bioreactor; cardiovascular disease; tissue engineering; Blood vessels","en","master thesis","","","","","","","","2020-11-23","","","","Biomedical Engineering","",""
"uuid:3ef7a56e-4062-4139-af98-5b8b60357416","http://resolver.tudelft.nl/uuid:3ef7a56e-4062-4139-af98-5b8b60357416","An intervention study to gain insight on sustainable water supply strategies in El Progreso, Panama: a Multidisciplinary Project in the Colon Province","Kleijn, Sarah (TU Delft Civil Engineering & Geosciences); Visser, Swaen (TU Delft Civil Engineering & Geosciences); Vollaers, Vita (TU Delft Civil Engineering & Geosciences); Wiggins, Joris (TU Delft Civil Engineering & Geosciences); van Wijngaarden, Jeroen (TU Delft Civil Engineering & Geosciences)","Ertsen, M.W. (mentor); Leijten, M. (mentor); Luxemburg, W.M.J. (mentor); de Krijger, K. (mentor); Delft University of Technology (degree granting institution)","2018","The main focus of this project is to gain insight into feasible strategies for sustainable water supply in a community inhabited by indigenous people. This was done by an intervention study in a small village called El Progreso in the province of Colon, on the Caribbean coast of Panama. The project aims to provide safe drinking water to the 80 members of the Embera tribe, living in El Progreso. This is done by constructing rainwater harvesting tanks where rainwater will be collected from roofs of houses and school buildings and stored within the tanks. We want to investigate the impact of this system, which supplies safe drinking water on a daily basis, on the community. The construction of the storage tanks (ferrocement) will stimulate and create local entrepreneurship. In these ways we will take our first step towards a sustainable local enterprise and sustainable employment. This can ultimately result in a long-term development in the El Progreso area. The project consists of 3 study topics: the physical construction of the rainwater harvesting tanks and the project control and quality that comes with this, evaluating the quality and quantity of available water sources in the area of rainwater and rainwater and the possible changes in the community due to this project (both the influence of the newly constructed tanks on daily life as well as the presence of aid in the community and social impacts that comes along with this). The project resulted in the construction of 11 tanks, improved job opportunities for several community members, improved trust in aid organizations as well as connecting the community to a national aid network for future projects.","Intervention study; Rainwater harvesting; Panama; Indigenous community","en","student report","","","","","","","","","","","","","MDP261",""
"uuid:145a6fba-4161-44c8-b6b7-df0b2a7e1947","http://resolver.tudelft.nl/uuid:145a6fba-4161-44c8-b6b7-df0b2a7e1947","The Potential of Blockchain for Financial Control in Construction Supply Chains","Visser, Ben (TU Delft Civil Engineering and Geosciences)","Wolfert, A.R.M. (mentor); van Nederveen, G.A. (mentor); Vrijhoef, R. (mentor); Delft University of Technology (degree granting institution)","2018","Blockchain technology is able to guarantee an immutable data record which could avoid disputes and litigations. It could also significantly reduce time and costs through process automation. The technology presents a potential solution for the many legal barriers in BIM, regarding ownership of information. This thesis will continue research based on these hypotheses by experimenting within a project transcending partnership in the Dutch social housing sector. For these partnerships alignment of business objectives and commercial interests is still lacking. An overarching goal through benefit-sharing agreements could be implemented by blockchain-enabled contract management. This could potentially result in better financial control and a lucrative business case, which are instrumental for actual adoption of new innovations.","Blockchain; Supply Chain Management","en","master thesis","","","","","","","","","","","","Civil Engineering | Construction Management and Engineering","",""
"uuid:6a86a544-198f-43b7-ae8a-8bd253482246","http://resolver.tudelft.nl/uuid:6a86a544-198f-43b7-ae8a-8bd253482246","Improved parcel merging for a parcel sorter system","Visser, Thijs (TU Delft Mechanical, Maritime and Materials Engineering)","Negenborn, R.R. (mentor); Duinkerken, M.B. (mentor); Delft University of Technology (degree granting institution)","2018","Within this research two new reservation control methods are examined for a parcel sorting system. Parcel sorting systems consist among other elements several infeed conveyors which are connected to a main conveyor. Parcels are then merged onto the main line. This is done using a First-Come-First-Serve method. This method experiences both a loss in throughput and an imbalanced throughput over all infeed conveyors. The two new methods improve the throughput and reduce the imbalance greatly.","Parcel sorting systems; Merge Sort; material handling","en","master thesis","","","","","","","","","","","","Marine Technology | Transport Engineering and Logistics","",""
"uuid:5c384dca-7a02-4b02-8cb7-0a5725e8f3ae","http://resolver.tudelft.nl/uuid:5c384dca-7a02-4b02-8cb7-0a5725e8f3ae","Improving Employee Engagement: A Digital Design Proposition for FlyCo","Visser, Wolke (TU Delft Industrial Design Engineering)","Snelders, H.M.J.J. (mentor); Price, R.A. (mentor); Gubler, Marissa (graduation committee); van Rooij, Marthe (graduation committee); Delft University of Technology (degree granting institution)","2018","","Employee Engagement; Design; Digital transformation; Interaction Design","en","master thesis","","","","","","","","2019-08-06","","","","Design for Interaction","",""
"uuid:f0e02f8f-d34e-4c64-9d4c-bad2b0157280","http://resolver.tudelft.nl/uuid:f0e02f8f-d34e-4c64-9d4c-bad2b0157280","Optimizing Shoreface Nourishment Design Using The Concept Of Equilibrium Beach Profiles: A Case Study In Nags Head","Visser, Ruben (TU Delft Civil Engineering and Geosciences; TU Delft Hydraulic Engineering)","Aarninkhof, Stefan (mentor); Reniers, Ad (mentor); de Schipper, Matthieu (mentor); Walstra, DJR (mentor); Kana, Timothy (mentor); Delft University of Technology (degree granting institution)","2018","Introduction and Problem Description: The autonomous nearshore morphodynamics along the Nags Head shoreline are characterized by consistent erosional behavior. The use of shoreface nourishments to counteract this erosion along shorelines has received considerable attention in the past, having the advantage of reduced cost compared to beach nourishments. Although shoreface nourishments are thus an increasingly interesting option for coastal managers, their design is often highly empirical and based on guidelines. A better understanding of the way a shoreface nourishment interacts with the antecedent bathymetry and respective forcing agents (i.e. - waves and tides) may help to reduce the degree of empiricism and possibly optimizing nourishment design in terms of longevity and shoreline sedimentation. Rather than using design guidelines, the present research aims to relate nourishment design to beach profile shaping parameters like wave climate and sediment characteristics.
Representation of beach profiles based on local wave dissipation, wave reflection and sediment characteristics have previously been studied in the form of equilibrium beach profiles (EBP). Recently major improvement in beach profile representations are made by including wave reflection in the energy balance, resulting in a two-sectioned EBP. After local site-specific parameter calibration, the vertical deviation between the initial profile and analogous calibrated EBP (z_{ebp} - z_{ini}) should indicate where a scarcity of sediment along the cross-shore profile is. Shoreface nourishments are then designed by filling in the vertical gaps between these two profiles. A hypothesis was postulated stating that the optimal form for a shoreface nourishment follows the equilibrium beach profile the best. The differences in impact conventional nourishment designs (based on guidelines) have on either cross-shore and longshore transport rates are computed and compared to an EBP-based design in two separate modeling studies.
Effects on cross-shore transport: Beach profile morphology and the response to shoreface nourishments are modeled in the 1D cross-shore profile model UNIBEST-TC. Three distinct conventional designs which have found recent applications are selected and based on either; extension of the outer bar, creating a new outer bar or filling in the trough shoreward of the outer bar. Analysis of the model results show that all four nourishment designs are incorporated well in the cross-shore morphodynamics as compared to the situation prior to construction.
The EBP-design shows strongest reduction of offshore directed transport, followed by designs based on filling in the trough, creating a new outer bar or extending the existing outer bar. Therefore the model simulations suggest that a nourishment design with the largest vertical deviations from the EBP may be the least effective to counteract coastal erosion. This partially confirms the postulated hypothesis that cross-shore transport rates are lowered most efficient while using the concept of EBP to design shoreface nourishments.
Effects on longshore transport: The coastal area flow model Delft3D was utilized for a series of numerical modeling simulations to examine the potential dependencies between nourishment design and post-dredging longshore transport rates and local gradients. Model results show a similar outcome as the cross-shore profile model, where the EBP-design results in the lowest longshore transport rates. Closer examination of the simulations, especially concerning the local gradients and longshore transport rates, show that the EBP-design reduces longshore gradients by a factor two up to four compared to conventional nourishment designs. The EBP-design therefore shows less sediment transport and local gradients because of a divergence of non-linear local sediment transport rates over the coastal zone. Confirming earlier studies that local longshore gradients dominate coastal change at the scale of nourishments and the hypothesis that shoreface nourishment design based on the concept of EBP is a more efficient way compared to conventional designs.
Practical applications: The results and theory demonstrate how the incoming wave climate and sediment characteristics are responsible for both the EBP shape and sediment transport. Since the erosion rates at the project site show local longshore variability, and the EBP shape remains constant even though using the same characteristics, the deviation between the initial- and EBP profile should indicate a gradient in longshore transport rates as well. Knowing this, the overall longshore gradient can be estimated using only one survey dataset. This could lead to a preliminary nourishment design, based on only one bathymetry survey and project budget. Approximation of longshore transport gradients could strongly improve the nourishment lifetime, especially in remote locations.
The constant longshore shape of the EBP with respect to MSL is furthermore efficient in reducing the local longshore transport gradients. Since the EBP-model is used as a template to fill in the vertical deviations between the initial profile and EBP, the longshore variabilities are spread out over the project site creating a less obstructive flow, thereby reducing longshore transport rates as well. Whereas conventional nourishment designs follow the original longshore variabilities and only enhance them, resulting in strong 3D bathymetrical features corresponding to coastal erosion as well.","Shoreface; Nourishment; Delft3D; Unibest","en","master thesis","","","","","","","","","","","","","",""
"uuid:d3998898-06ca-485a-afb6-cfcab3fb9374","http://resolver.tudelft.nl/uuid:d3998898-06ca-485a-afb6-cfcab3fb9374","Borderscape: Increasing the level of permeability in between land and sea (in Northern Netherlands)","Visser, Malou (TU Delft Architecture and the Built Environment)","Piccinini, D. (mentor); Kuzniecow Bacchin, T. (mentor); Delft University of Technology (degree granting institution)","2018","The sea dike is a spatial interim in the dialogue between human at land and natural forces at the Wadden sea. Standing on the dike gives me a feeling of conquest but also of separation. It stands out as a green wall between two worlds and stretches in the wide, open landscape as far as my eyes can see. This narrow edge has once been marshlands, a gradual transition between land and sea. Now, the dike abruptly excludes the exchange of the natural phenomena between them. Seawards, the tidal gullies are hardly visible as the sedimentation is too high. On the other side, on reclaimed land, straight ditches regulate the fresh water level to serve the big agricultural plots. The modernization of the last centuries has led to a functional coastal landscape in the Northern Netherlands with hardly any ecological, economic and social development along the dike. Instead, people have turned their back against the sea and forgotten the existence of, and potential coexistence with, it.
A dialogue is a continuous process. The increasing tidal volume and effect of salinization caused by relative climate change asks for a new perspective on the edge between land and sea. To what extent will we hold on to the belief that the dike as a thin, rigid line will protect us in a sustainable way against change? In my project these effects are not seen as threats but as a stimulus to deal with uncertain outcomes in spatial design. Creating a gradual transition zone will increase the level of resilience and establish ecological and social development.
Looking at natural ecologies, the edge is after all the zone of the highest living activity. Making the dike more permeable has many gradations but in all cases the existing landscape with its traces will be taken as found. Using site-specific differences in topography, soil type and water infrastructure including the generic processes, will help to locate the suitable level and type of permeability. Revealing and reintroducing natural phenomena in different forms will make the narrative of the coastal dynamics in this landscape legible again.