"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:da0041d8-2f77-4716-8816-d70e0c66cd05","http://resolver.tudelft.nl/uuid:da0041d8-2f77-4716-8816-d70e0c66cd05","Classifying Human Manual Control Behavior Using LSTM Recurrent Neural Networks","Versteeg, Rogier (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2024","This article discusses a long short-term memory (LSTM) recurrent neural network that uses raw time-domain data obtained in compensatory tracking tasks as input features for classifying (the adaptation of) human manual control with single- and double-integrator controlled element dynamics. Data from two different experiments were used to train and validate the LSTM classifier, including investigating effects of several key data preprocessing settings. The model correctly classifies human control behavior (cross-experiment validation accuracy 96%) using short 1.6-s data windows. To achieve this accuracy, it is found crucial to scale/standardize the input feature data and use a combination of input signals that includes the tracking error and human control output. A possible online application of the classifier was tested on data from a third experiment with time-varying and slightly different controlled element dynamics. The results show that the LSTM classification is still successful, which makes it a promising online technique to rapidly detect adaptations in human control behavior.","Behavioral sciences; Classification; cybernetics; Data models; Frequency control; human–machine systems; manual control; neural networks; Pattern recognition; Real-time systems; Task analysis; Training","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-03","","","Control & Simulation","","",""
"uuid:a1941ca3-b824-40e3-904c-3d80bce999a1","http://resolver.tudelft.nl/uuid:a1941ca3-b824-40e3-904c-3d80bce999a1","Techno-Economic Comparison of Electricity Storage Options in a Fully Renewable Energy System","Mulder, Sebastiaan (Student TU Delft); Klein, S.A. (TU Delft Energy Technology)","","2024","To support increasing renewable capacity for a net-zero future, energy storage will play a key role in maintaining grid stability. In this paper, all current and near-future energy storage technologies are compared for three different scenarios: (1) fixed electricity buy-in price, (2) market-based electricity buy-in price, and (3) energy storage integrated into a fully renewable electricity system. In the first part of this study, an algorithm is devised to simulate strategic buy-in of electricity for energy storage. This analysis yields a qualitative decision-making tool for a given energy storage duration and size. Building upon the first part’s findings, an integration study gives insight into expected power prices and expected storage size in a typical northwestern European fully renewable energy system. The integration study shows significant need for electricity storage with durations spanning from one to several days, typically around 40 h. Pumped Hydro Storage and Pumped Thermal storage surface as the best options. The overall levelized costs of storage are expected to be in the USD 200–500/MWh range. Integration of storage with renewables can yield a system-levelized cost of electricity of about USD 150/MWh. Allowing flexibility in demand may lower the overall system-levelized cost of electricity to USD 100/MWh.","batteries; energy storage; grid stability; LCOE; markets; modelling; net-zero","en","journal article","","","","","","","","","","","Energy Technology","","",""
"uuid:e9f92bbb-0fbd-409f-be4f-86ad1b78f9cd","http://resolver.tudelft.nl/uuid:e9f92bbb-0fbd-409f-be4f-86ad1b78f9cd","Using problem-based exploratory training to improve pilot understanding of autopilot functions","van Leeuwen, J.K. (TU Delft Control & Simulation); Landman, H.M. (TU Delft BUS/TNO STAFF; TU Delft Control & Simulation); Groen, Eric L. (DIANA FEA); Mumaw, Randall J. (San José State University); Stroosma, O. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2024","Previous research indicated a need to improve pilot training with regard to understanding of autopilot logic and behavior, especially in non-routine situations. Therefore, we tested the effect of problem-based exploratory training on pilots’ understanding of autopilot functions. Using a moving-base flight simulator, general aviation pilots (n = 45) were trained to diagnose failures either without foreknowledge and guidance (exploratory group), without foreknowledge but with some guidance (exploratory-guidance group) or with foreknowledge and full guidance (control group). They subsequently performed six test scenarios in which their understanding of the effects of failures was tested by requiring them to deduce the failures and select autopilot modes that were still functioning. Those who received exploratory training with guidance were significantly more likely than the other groups to diagnose failures correctly. The exploratory training group also selected the most appropriate functioning autopilot modes significantly faster than the control group. The results suggest that exploratory training with an appropriate level of guidance is useful for gaining a practical understanding of autopilot logic and behavior. Exploratory training may help to improve transfer of training to operational practice, and prevent automation surprises and accidents.","Automation surprise; Human–automation interaction; Simulator training; Situation awareness; Transfer of training","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:98dbb10d-8911-49d2-8a36-17fc5be73129","http://resolver.tudelft.nl/uuid:98dbb10d-8911-49d2-8a36-17fc5be73129","Stationary-phase analysis of time-shift extended imaging in a constant-velocity model","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2024","To estimate the depth errors in a subsurface model obtained from the inversion of seismic data, the stationary-phase approximation in a two-dimensional constant-velocity model with a dipped reflector is applied to migration with a time-shift extension. This produces two asymptotic solutions: one is a straight line, and the other is a curve. If the velocity differs from the true one, a closed-form expression of the depth error follows from the depth and apparent dip of the reflector as well as the position of the amplitude peak at a non-zero time shift, where the two solutions meet and the extended migration image focuses. The results are compared to finite-frequency results from a finite-difference code. A two-dimensional synthetic example with a salt diapir illustrates how depth errors can be estimated in an inhomogeneous model after inverting the seismic data for the velocity model.","computing aspects; inverse problem; mathematical formulation; seismics; wave","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:d5f9bd8c-3c51-462e-8cf0-472864e1a798","http://resolver.tudelft.nl/uuid:d5f9bd8c-3c51-462e-8cf0-472864e1a798","A highly stable, pressure-driven, flow control system based on Coriolis mass flow sensors for organs-on-chips","de Haan, Pim (Rijksuniversiteit Groningen; TI-COAST); Mulder, Jean Paul S.H. (Rijksuniversiteit Groningen); Lötters, J.C. (TU Delft Precision and Microsystems Engineering; Bronkhorst High-Tech BV; University of Twente); Verpoorte, Elisabeth (Rijksuniversiteit Groningen)","","2024","Stable delivery of liquids to microfluidic systems is essential for their reproducible functioning, especially when supplying flows to organs-on-chips – delicate living models that recreate human physiology on the microscale and thus can be used to reduce the need for animal testing. Most flow control systems are unable to sustain a robust and stable flow in longer experiments (>1 week), particularly those based on the ubiquitous syringe pump. Though easy to use, syringe pumps have no mechanism for actually measuring flow, let alone flow regulation with sensor feedback. We have developed a liquid delivery system based on the generation of flow by applying a constant air pressure to liquids in sealed containers. A flow of liquid is monitored by accurate measurement of mass flows (mg/min) using downstream Coriolis-based mass flow sensors. Measured mass flows provide fast feedback to integrated valves, with valves opening or closing slightly to increase or decrease solution flows to the organs-on-chips as required. This mass flow sensing principle is not affected by changes in the density, temperature, and viscosity of the liquids being displaced. This is in contrast to systems that use volumetric flow sensors, which require recalibration when these parameters change. The rationale behind using this principle for organs-on-chips, is that the stability provided by this flow control system allows for more control over growth of these mini-organs. We demonstrate the functionality of this system with three examples: 1) Fast stabilization (within seconds) under changing physical conditions; 2) Short-term stability (minutes to hours) of delivered flows in a microreactor with interconnected inlets; and 3) Long-term stability (>1 week) of cell medium flows to a living organ-on-a-chip. Two categories of organs-on-chips (OOCs) can be distinguished: 1) solid OOC are designed for three-dimensional cell or tissue constructs that interact with each other and their surroundings, and 2) barrier-type OOC contain a selective cellular barrier between two compartments as do many barriers in the body. The latter of these two types is the most challenging to culture and maintain as they are very sensitive to variations in flow and pressure surges. The flow control system presented in this work provides a great improvement compared to the use of syringe pumps and volumetric flow sensors in OOC studies. The novelty of this work lies in the long-term stability use of this system for organs-on-chips, maintaining stability for short to very long periods of time without compromising the barrier function of the organ-on-chip by pressure surges, bacterial contamination, or other undesired effects from the flow delivery system.","Coriolis flow sensor; Flow control system; Flow stability; Organ-on-a-chip","en","journal article","","","","","","","","","","Precision and Microsystems Engineering","","","",""
"uuid:11a27e7d-8d43-47ed-91b5-99dc1b3264de","http://resolver.tudelft.nl/uuid:11a27e7d-8d43-47ed-91b5-99dc1b3264de","Shaping the nanoworld: From precursors to functional nanocrystals","Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials)","Houtepen, A.J. (promotor); Manna, L. (promotor); Delft University of Technology (degree granting institution)","2023","","Nanocrystals; Quantum dots; Photoluminescence; Electrochemistry; Perovskite; Indium Phosphide; Lanthanides; Phosphors; Quantum Yield; Energy Transfer; Chemical Synthesis; Doping; Lattice Matching; Quenching; Yb:YLF; InZnP; CsPbBr3; LiYF4; Ytterbium; Surface Chemistry; Ligands","en","doctoral thesis","","978-94-6473-048-5","","","","","","2024-04-25","","","ChemE/Opto-electronic Materials","","",""
"uuid:15509f00-c9f2-4b1a-8edf-d9c6761d3224","http://resolver.tudelft.nl/uuid:15509f00-c9f2-4b1a-8edf-d9c6761d3224","Factors favouring vegetation in quay masonry walls: A pilot field study","Mulder, K.B. (TU Delft Architectural Technology); Lubelli, B. (TU Delft Heritage & Architecture); Dijkhuis, Edwin (Floron - Plant Conservation Netherlands)","","2023","Walls overgrown with plants can have a positive impact on urban comfort and contribute to biodiversity in the city. In particular, quay walls, thanks to their close contact with water, have the potential to be ecologically engineered to encourage the growth of herbaceous plants. Different factors can affect growth of vegetation on walls. This research aims at experimentally investigating the effect of several variables, including quay wall design, building materials and environmental conditions, on receptivity of brick masonry quay walls for herbaceous plants. To this scope, ten quay walls (size 2 m × 2 m x 0.43 m), have been built and placed in a canal in the city of Breda (the Netherlands). The survival and growth of vegetation and the moisture content in the wall were monitored during a period of about 2 years. The results show that the presence of a layer of soil substrate with high capillary suction, positioned in between the masonry cladding and the concrete structure of the wall, has the most relevant positive effect on vegetation growth on the masonry. Mortar composition and irregularities of the wall surface influence bio-receptivity too, but to a less extent; orientation had only a limited effect. Moreover, the strategy of using a mechanically strong bedding mortar in combination with a weaker but more bio-receptive pointing mortar has proven successful at favouring growth of herbaceous plants, while providing sufficient strength to the masonry.","Green wall; Quay wall; Nature-inclusive design; Wall vegetation; Monitoring","en","journal article","","","","","","","","","","","Heritage & Architecture","","",""
"uuid:efa4f555-d392-4438-8c61-43b2d211cf08","http://resolver.tudelft.nl/uuid:efa4f555-d392-4438-8c61-43b2d211cf08","Simulator Assessment of the Lateral-Directional Handling Qualities of the Flying-V","Joosten, S.K.B. (Student TU Delft); Stroosma, O. (TU Delft Control & Simulation); Vos, Roelof (TU Delft Flight Performance and Propulsion); Mulder, Max (TU Delft Control & Simulation)","","2023","Flying wings are known for their limited lateral-directional stability and handling qualities. This study aims at assessing the lateral-directional handling qualities of a conceptual flying wing aircraft currently in development at TU Delft, the Flying-V, in a moving-base flight simulator. It focuses on two aspects: First assess the lateral-directional handling qualities of the bare-airframe Flying-V, and the compliance to quantitative requirements. Second, improve these handling qualities through a prototype flight control system, and assess its effect on the handling qualities and the requirement compliance. These assessments were performed both analytically and with a pilot-in-the-loop simulator experiment, in order to experimentally validate analytical findings and obtain new pilot-subjective insights. The analytical and experimental assessment for lowspeed flight conditions both show the lateral-directional handling qualities of the Flying-V to be insufficient for requirement compliance, due to a lack of pitch, roll and yaw control authority and an insufficiently stable Dutch roll eigenmode. The prototype flight control system, consisting of an adapted control allocation and a stability augmentation system, showed both analytically and experimentally to improve the control authority, stability, and handling qualities of the Flying-V. While the effect on the lateral-directional stability was sufficient for stability requirement compliance, the control authority was not sufficiently increased for maneuverability requirement compliance at low speed. Thus, if the landing speed is not increased from the current baseline, a challenge remains to improve the handling qualities of the Flying-V. An approximation of the control authority required for full requirement compliance in the low-speed flight conditions tested showed a control authority increase of over a factor four to be required in that case.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:11d55e6d-8511-4d6e-ac41-fc646be032c6","http://resolver.tudelft.nl/uuid:11d55e6d-8511-4d6e-ac41-fc646be032c6","Sensitivity analysis of a minimum lateral control speed prediction system","Bouwman, F. (Student TU Delft); Stroosma, O. (TU Delft Control & Simulation); in 't Veld, A.C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","Preventing Loss of Control In-flight (LOC-I) in commercial and general aviation is an active research area with numerous proposed solutions. One of these solutions aims to prevent lateral LOC-I, a special type of LOC-I, by presenting a roll-performance based minimum lateral control speed to the pilot in roll-limited situations, such as single-engine failure scenarios in multi-engine aircraft. This minimum lateral control speed is predicted by a system, named the Vc Prediction System (VPS), which continually predicts the minimum lateral control speed Vc at which an aircraft can still obtain a certain roll angle within a certain amount of time. It consists of three components; a linear model, a parameter estimation method and a Vc prediction model. These VPS components were designed for a simulation model of the Piper Seneca. This study analyzes the sensitivity of the VPS design to a change in aircraft dynamics and simulation model complexity by redesigning this system for a high-fidelity simulation model of the Fokker 50. The results show that both aircraft favor a small linear model and the Modified Kalman Method for parameter estimation. The original Vc prediction model however gives higher Vc prediction errors for the Fokker 50 than for the Piper Seneca. By simplifying the original Vc prediction model a stable, smooth and relatively accurate Vc prediction for the Fokker 50 can be obtained.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:bf16e501-9df4-45be-beea-5a1296325e75","http://resolver.tudelft.nl/uuid:bf16e501-9df4-45be-beea-5a1296325e75","Using the Hess Adaptive Pilot Model for Modeling Human Operator's Control Adaptations in Pursuit Tracking","Jakimovska, N. (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","An improved understanding of pilot’s control behavior adaptations in response to sudden changes in the vehicle dynamics is essential for realizing adaptive support systems that remain effective when task characteristics suddenly change. In this paper, we replicate, extend, and validate the ‘adaptive pilot model’ proposed by Hess to verify its effectiveness for predicting human adaptive behavior in pursuit tracking tasks. The model relies on a Triggering function, that compares the current tracking performance to a stored nominal (pre-transition) state, and an Adaptation mechanism which determines new adapted human operator gain settings proportional to the magnitude of the off-nominal error occurrences. For model validation data from a previous experiment were used, where ten participants performed a pursuit tracking task with transitions in controlled element dynamics from a single to a double integrator, and vice versa. Overall, with an added human operator delay and participant-specific inner- and outer-loop gain adjustments, the model was found to accurately describe the measured steady-state tracking behavior for the participants in our data set. The results for the time-varying single integrator to double integrator transitions showed that the model can capture the transient control behavior of participants. However, the adaptive logic could only be tuned to activate for participants that had a pre-transition crossover frequency above 0.9 rad/s. Furthermore, the model was not able to capture the change in control behavior for transitions from a double to a single integrator. Here, as no distinct degradation in tracking performance occurs for such a transition to a more easily controlled system, the model's proposed Triggering logic will not activate. Further investigation and more experiment data are required for improving the applicability of the model's adaptive logic and to enable more accurate prediction of adaptive human control behavior.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:ba09adbf-1c3f-4fb2-ac51-511d46e38be2","http://resolver.tudelft.nl/uuid:ba09adbf-1c3f-4fb2-ac51-511d46e38be2","Procedure and Interface Design for Continuous Descent Approaches Under End Time Constraints","Vasilopoulos, V.G. (Student TU Delft); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); in 't Veld, A.C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","The Continuous Descent Approach (CDA) offers reduced aircraft noise emissions and fuel consumption, but the obstacle limiting it to reduced traffic density conditions, is the low predictability of the trajectory and Estimated Time of Arrival (ETA). The solution proposed by this research is to develop a pilot support interface to facilitate the execution of a fixed flight path angle CDA, where thrust is not limited to idle and a velocity profile can be tracked, which will lead to a selected ETA. Initially, the CDA trajectory was investigated through an aerodynamic model, while the solution space of the ETA and the calculation of the stepwise velocity profile were defined. Following the analysis of the pilot’s role, a two-fold support interface was designed based on Ecological Interface Design (EID), with a Vertical Situation Display (VSD) playing a central role for planning and execution. The interface was tested in a MATLAB®/Simulink® setup and five pilots were recruited to execute simulations over different wind conditions. Their on-time performance was satisfactory, while they worked with the provided cues and suggested some interface changes to offer more flexibility. A more robust application of the proposed approach can lead to a wider adoption of the CDA, as a validated procedure.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:61dc0642-4f6a-4324-ac49-5e0b4753ad22","http://resolver.tudelft.nl/uuid:61dc0642-4f6a-4324-ac49-5e0b4753ad22","Simulator Evaluation of Flightpath-oriented Control Allocation for the Flying-V","Vugts, G. (Student TU Delft); Stroosma, O. (TU Delft Control & Simulation); Vos, Roelof (TU Delft Flight Performance and Propulsion); Mulder, Max (TU Delft Control & Simulation)","","2023","A novel aircraft configuration, the tailless Flying-V, is examined for its longitudinal handling qualities in cruise by means of piloted simulations. The Flying-V is controlled by two aileron/elevator (elevon) surfaces on each side, and rudders on each wingtip. Two control allocation schemes were created: a conventional one where both inboard and outboard elevons deflect in the same direction, and one where the change in lift the elevons generate is countered by deploying the inboard and outboard elevons in opposite directions, allowing more direct control of the resulting flight path. The longitudinal handling qualities in cruise conditions were investigated by pilot opinion in a moving base simulator. Three experiments were conducted: a traditional pitch tracking experiment with the conventional control allocation, and a new flight-path-angle tracking experiment, using both the conventional and the flight-path-oriented control allocation. The pilots indicated the conventional pitch attitude control to have Level 1 handling qualities for the pitch control task, and Level 2 for the flight path control task. The flight-path-oriented control allocation improved the performance of the pilots during the flight-part tracking experiment, but the perceived control authority was considered too small for most pilots to consistently rate it at Level 1.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:73b44772-e40f-4a26-aa7b-b4b63ed12afe","http://resolver.tudelft.nl/uuid:73b44772-e40f-4a26-aa7b-b4b63ed12afe","Piloted Simulator Evaluation of Low-Speed Handling Qualities of the Flying-V","Torelli, R. (Student TU Delft); Stroosma, O. (TU Delft Control & Simulation); Vos, Roelof (TU Delft Flight Performance and Propulsion); Mulder, Max (TU Delft Control & Simulation)","","2023","An improved understanding of pilot’s control behavior adaptations in response to sudden changes in the vehicle dynamics is essential for realizing adaptive support systems that remain effective when task characteristics suddenly change. In this paper, we replicate, extend, and validate the ‘adaptive pilot model’ proposed by Hess to verify its effectiveness for predicting human adaptive behavior in pursuit tracking tasks. The model relies on a Triggering function, that compares the current tracking performance to a stored nominal (pre-transition) state, and an Adaptation mechanism which determines new adapted human operator gain settings proportional to the magnitude of the off-nominal error occurrences. For model validation data from a previous experiment were used, where ten participants performed a pursuit tracking task with transitions in controlled element dynamics from a single to a double integrator, and vice versa. Overall, with an added human operator delay and participant-specific inner- and outer-loop gain adjustments, the model was found to accurately describe the measured steady-state tracking behavior for the participants in our data set. The results for the time-varying single integrator to double integrator transitions showed that the model can capture the transient control behavior of participants. However, the adaptive logic could only be tuned to activate for participants that had a pre-transition crossover frequency above 0.9 rad/s. Furthermore, the model was not able to capture the change in control behavior for transitions from a double to a single integrator. Here, as no distinct degradation in tracking performance occurs for such a transition to a more easily controlled system, the model's proposed Triggering logic will not activate. Further investigation and more experiment data are required for improving the applicability of the model's adaptive logic and to enable more accurate prediction of adaptive human control behavior.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:6fece11b-8aff-4e20-a670-382cf0c1ab80","http://resolver.tudelft.nl/uuid:6fece11b-8aff-4e20-a670-382cf0c1ab80","Improving rowing performance by adjusting oar blade size and angle","van Nieuwburg, W.C.A.M. (Student TU Delft); van Spreuwel, B.J.J. (Student TU Delft); Tran, Minh Tâm Kevin (Student TU Delft); Yang, M.D. (Student TU Delft); Greidanus, A.J. (TU Delft Fluid Mechanics); Mulder, G. (Student TU Delft); Tummers, M.J. (TU Delft Fluid Mechanics); Westerweel, J. (TU Delft Fluid Mechanics); Suijker, W. (Maritime Research Institute Netherlands (MARIN)); van Wijk, R. (Maritime Research Institute Netherlands (MARIN))","","2023","The principal aim of the work presented here is to investigate and demonstrate that a forward tilted rowing blade would result in a more efficient and effective motion of the blade through the water that would result in a higher boat speed when an equal input power is provided. A 1:5 scaled rowing boat is used to determine the performance of rowing blades with different sizes and blade angles. This is used to validate the results of a previous study where the optimal blade angle of 15 (Formula presented.) with respect to the oar shaft was determined (1). The input power and speed of the rowing boat can be compared between original and modified oar blades. Measurements in a towing tank demonstrate that a modified rowing blade result in faster rowing by 0.4% at the same input power. Maintaining the same stroke rate, the improvement of the blade efficiency is compensated by using a 4–6% increased blade area to yield the same input power.","rowing blade; performance; efficiency; optimisation; robot","en","journal article","","","","","","","","","","","Fluid Mechanics","","",""
"uuid:334c7661-a53b-4f06-9a8e-8033b2095bba","http://resolver.tudelft.nl/uuid:334c7661-a53b-4f06-9a8e-8033b2095bba","Automation on thermal control of blast furnace","Masuda, Ryosuke (JFE Steel Corp.); Hashimoto, Y. (JFE Steel Corp.); Mulder, Max (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Kano, Manabu (Kyoto University)","","2023","Accurate process control through automation is the key to achieving efficient and stable operation of a blast furnace. In this study, we developed an automatic control system of hot metal temperature (HMT). To cope with the slow and complex process dynamics of the blast furnace, we constructed a control algorithm that predicts eight-hour-ahead HMT using a two-dimensional (2D) transient model and calculates optimal target pulverized coal ratio (PCR) and pulverized coal flow rate by non-linear model predictive control (NMPC). An evaluation in a real plant showed that the developed control system suppressed the effects of disturbances, such as changes in the coke ratio and blast volume, on the HMT. The root mean square (RMS) of the control deviation of HMT was successfully reduced by 1.6 °C compared to the conventional manual operation.","Hot metal temperature; Industrial application; Model predictive control; Process control","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:a80547b8-0092-42f9-b75e-bc4e3d78ca85","http://resolver.tudelft.nl/uuid:a80547b8-0092-42f9-b75e-bc4e3d78ca85","Modeling driver steering behavior in restricted-preview boundary-avoidance tasks","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","In the design of human-like steering support systems, driver models are essential for matching the supporting automation's behavior to that of the human driver. However, current driver models are very limited in capturing the driver's adaptation to key task variables such as road width and visibility (i.e., 'preview' of the road ahead). This paper uses a recently proposed, novel control-theoretical model for centerline tracking to investigate driver steering in lane-keeping tasks with restricted and unrestricted preview, in an attempt to substantially extend this model's validity. Using data from a tailored driving simulator experiment, three driver control loops (feedforward, heading and position feedback) are separately quantified using system identification techniques. The results show that when preview is restricted, drivers use all of the remaining preview to anticipate the curves of the road ahead, and are no longer able to 'smooth' tight curves in the road trajectory (i.e., corner cutting). When sufficient preview and lane width are available, the time to line crossing increases, and steering behavior is less aggressive and more intermittent, or more 'satisficing'. The novel driver steering model captures these adaptations very well (over 95% of the steering actions) and can thereby be instrumental in realizing human-like steering automation and support systems.","Driver behavior; Driver modeling; Preview; Reduced visibility; Steering","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:d883c231-8331-4fa6-9d70-e52c4aad1e08","http://resolver.tudelft.nl/uuid:d883c231-8331-4fa6-9d70-e52c4aad1e08","Supplementing Haptic Feedback in Flight Envelope Protection Through Visual Display Indications","de Rooij, G. (TU Delft Control & Simulation); van Baelen, D. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","Haptic cues on the side stick are a promising method to reduce loss of control in-flight incidents. They can be intuitively interpreted and provide immediate support, leading to a shared control system. However, haptic interfaces are limited in providing information, and the reason for cues may not always be clear to pilots. This study presents the results of the conceptual development of visual display symbology that supports haptic feedback on the side stick in communicating flight envelope boundaries to pilots. Novel indications for the limits of airspeed, load factor, angle of attack, and angle of bank, which for the first time simultaneously indicate magnitude and direction of the haptic cues, were integrated in an Airbus primary flight display. The symbology was tested in a pilot-in-the-loop experiment with professional Airbus pilots (N=16) flying several approaches in alternate law with haptic feedback. Objective results do not show clear improvements, although the time spent outside the flight envelope is slightly reduced. Subjective results indicate a preference, however, for the new display and an increased understanding of the haptic feedback. Further research is recommended to improve the interface design, remove unused indications, and test a bank scenario using current operational bank limits.","Flight Envelope Protection; Flight Display Systems; Aircraft Flight Control System; Airbus Aircraft; Primary Flight Display; Flight Deck; Human-In-The-Loop; Angle of Attack; Human-Machine Interaction","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:37a03c0a-5214-4247-9dd6-f2d2c9d091dc","http://resolver.tudelft.nl/uuid:37a03c0a-5214-4247-9dd6-f2d2c9d091dc","Navigating Approaches to the Use of Pattern Language Theory in Practice","Chen, Ruihua (Beijing Shangyi Heart Technology Co. Ltd); Bos-de Vos, M. (TU Delft Methodologie en Organisatie van Design); Mulder, I. (TU Delft Design Conceptualization and Communication); van Eldik, Zoë (Wageningen University & Research)","","2023","Christopher Alexander’s Pattern Language Theory (PLT) has been recognized as a valuable methodology to understand complex systems. It has been applied across domains through a variety of different approaches. This article reviews exist-ing approaches to PLT application and reflects upon the differences between them. We find that application generally differs across four components: artefact, activity, roles and tools, informed by practitioners’ diverging values and needs. We elaborate on how consciously navigating the dimensions that these components consist of can help to broaden the application of PLT in practice. We report on the development of a set of conceptual tools that aim to support this process. The resulting “activity kit” has been applied in a Dutch housing renovation project to support homeowners in communication and decision‐making to illustrate the applicability of our methodology. It can be concluded that the “activity kit” is a promising approach to broaden the use of PLT and contributes to the methodological repertoire of researchers and practitioners to address complexity in today’s societal challenges.","action repertoire; design methodology; housing renovation; literature synthesis; pattern language theory","en","journal article","","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:61588ae9-bbba-4afe-85ab-a6e277f1148f","http://resolver.tudelft.nl/uuid:61588ae9-bbba-4afe-85ab-a6e277f1148f","Probabilistic Prediction of Longitudinal Driving Behaviour for Driving Simulator Pre-Positioning","Eppink, J.M. (TU Delft Control & Simulation; BMW Group); Kolff, M.J.C. (TU Delft Control & Simulation; BMW Group); Venrooij, Joost (BMW Group); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","Due to the non-deterministic nature of longitudinal human driver behaviour, motion cueing algorithms currently cannot fully utilize the workspace of driving simulators. This paper explores the possibility of using various predictor variables to predict longitudinal driving behaviour. Through the development of a logistic regression model, it is shown that a combination of the current vehicle velocity, the speed limit eight seconds ahead and the accelerator pedal deflection yields the most accurate estimate of the probabilities that drivers will accelerate or decelerate. Based on these probabilities, a driving simulator was linearly pre-positioned in combination with a classical washout algorithm. The perceived motion incongruence was subjectively evaluated by the drivers (N = 34), testing: (i) no pre-positioning, (ii) pre-positioning, and (iii) pre-positioning with an increased longitudinal classical washout gain enabled by the pre-positioning. Results show that the pre-positioning improves the margins with respect to the longitudinal workspace limits (better workspace management), without affecting the motion incongruence ratings. When using the increased margins to increase the longitudinal gain, however, no significant reduction in motion incongruence ratings was observed. This is likely due to the small motion space of the hexapod motion system used in the current study. However, this paper shows that longitudinal driving behaviour can be accurately predicted and can enable improved workspace utilization for driving simulators.","Motion cueing; behaviour prediction; pre-positioning; workspace management","en","conference paper","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-01","","","Control & Simulation","","",""
"uuid:828b21f0-d32a-4e61-9b4f-88a1a2ade6d6","http://resolver.tudelft.nl/uuid:828b21f0-d32a-4e61-9b4f-88a1a2ade6d6","Driving Simulator Experiment Stakeholder Perspectives on Motion Cueing Algorithm Quality","Kolff, M.J.C. (TU Delft Control & Simulation; BMW Group); Venrooij, Joost (BMW Group); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","In driving simulation, the choice of a simulator, motion cueing algorithm, and associated set of tuning parameters for an experiment is typically made with an exclusive focus on the quality of the motion. In practice, many other metrics could affect this choice as well, such as tuning complexity, algorithm stability, or the financial costs of the simulation. Arguably, the complete motion cueing algorithm quality is thus more than the quality of the motion alone. This paper presents results of a survey which attempted to identify the most important metrics from the perspective of the main experiment stakeholders. Four stakeholder groups in typical driving simulator experi- ments are defined: The experimenters, motion cueing engineers, operators, and participants. All groups received the same survey, asking them to indicate how important various metrics are for them. Results show that, next to the quality of the motion, experimenters and participants are generally interested in reducing simulator sickness. The motion cueing engineers rank tuning effort and tuning complexity as most important metrics. Operators prefer an easy to use and overall stable motion cueing. A typical BMW experiment is discussed as example, which shows that the choice for a simulator and motion cueing algorithm can indeed differ when including these metrics in a trade-off, compared to when only motion quality is considered. The presented methods allow for a better, multi- faceted selection of the simulator, motion cueing algorithm, and associated tuning parameters, improving future driving simulation experiments.","Motion cueing; quality comparison; objective assessment; stakeholder survey","en","conference paper","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-01","","","Control & Simulation","","",""
"uuid:8b8175c9-10a4-4762-90e6-d437f2ff3632","http://resolver.tudelft.nl/uuid:8b8175c9-10a4-4762-90e6-d437f2ff3632","Performance of old and new mass-lumped triangular finite elements for wavefield modelling","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2023","Finite elements with mass lumping allow for explicit time stepping when modelling wave propagation and can be more efficient than finite differences in complex geological settings. In two dimensions on quadrilaterals, spectral elements are the obvious choice. Triangles offer more flexibility for meshing, but the construction of polynomial elements is less straightforward. The elements have to be augmented with higher-degree polynomials in the interior to preserve accuracy after lumping of the mass matrix. With the classic accuracy criterion, triangular elements suitable for mass lumping up to a polynomial degree 9 were found. With a newer, less restrictive criterion, new elements were constructed of degree 5–7. Some of these are more efficient than the older ones. To assess which of all these elements performs best, the acoustic wave equation is solved for a homogeneous model on a square and on a domain with corners, as well as on a heterogeneous example with topography. The accuracy and runtimes are measured using either higher-order time stepping or second-order time stepping with dispersion correction. For elements of polynomial degree 2 and higher, the latter is more efficient. Among the various finite elements, the degree-4 element appears to be a good choice.","acoustics; computing aspects; modelling; numerical study; seismics; wave","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:5bbdd7aa-5d43-48e6-974c-ebcf76d3472a","http://resolver.tudelft.nl/uuid:5bbdd7aa-5d43-48e6-974c-ebcf76d3472a","Contributing Factors to Flight-Centric Complexity in En-Route Air Traffic Control","de Rooij, G. (TU Delft Control & Simulation); Stienstra, A. (Student TU Delft); Borst, C. (TU Delft Control & Simulation); Tisza, A. B. (EUROCONTROL); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","To alleviate the workload of air traffic controllers, part of the air traffic may be handled by a future automated system. When deciding which flights to delegate, a distinction can be made between basic and non-basic flights, with the former being prime candidates for delegation. The human controller can then focus on the non-basic flights, where human competencies are most valuable and more difficult to automate. The classification of flights is preferably based on objective measures relating to the traffic situation. Existing complexity models are, however, often used for capacity predictions or airspace restructuring and primarily to assess the complexity of a sector as a whole. In this paper we use empirically collected flight complexity ratings from 15 professional en-route air traffic controllers. They indicated which other flights contributed to their complexity assessment of a single flight of interest. This exploratory study was able to build a machine-learning model which adequately classifies these flights, based on a qualified majority of controllers. By analyzing the interactions between the included flights, we discuss whether a classification model can differentiate between basic and non-basic flights, and which traffic features play the largest role. Once this can be done reliably and an appropriate complexity threshold has been chosen, a model can be developed as a starting point for an automatic allocation algorithm that distributes flights between a human controller and the computer.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:b2d4fb9e-5cc0-454a-85b6-7a2fc1f1d667","http://resolver.tudelft.nl/uuid:b2d4fb9e-5cc0-454a-85b6-7a2fc1f1d667","3D geomechanical modelling of induced seismicity including intersecting faults and reservoir compartments","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2023","To investigate the physical processes behind induced seismicities due to, for example, production of hydrocarbons from a reservoir, most of the earlier studies performed geomechanical simulations on a simple reservoir geometry. The effect of fluid depletion is, in general, simulated for such a simple geometry. Neglecting the contribution of realistic 3-D reservoir geometries can lead to a wrong estimation of the incremental stress field. A reliable estimate of the induced stress field is key to producing meaningful simulation results. We perform geomechanical simulations on a simple fault model as well as a more realistic model based on the known geological structures at the earthquake source-region in Zeerijp region, the Netherlands. Our results demonstrate that the angle of the fault intersection affects the incremental stress field, including the effective normal stress, the shear stress, and hence, the Coulomb stress and the SCU value. Our results also show a shift in the rupture pattern and the location of the maximum slip on the fault plane. We conclude that, to properly evaluate the effects of production activities and to simulate precisely the in-situ stress field and the induced seismicity, the incorporation of a realistic reservoir structure in modelling is essential.","","en","conference paper","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:04871dc3-8642-45c5-a7e6-447fd36baa27","http://resolver.tudelft.nl/uuid:04871dc3-8642-45c5-a7e6-447fd36baa27","Nucleation and Growth of Bipyramidal Yb:LiYF4 Nanocrystals─Growing Up in a Hot Environment","Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Jenkinson, Kellie (Universiteit Antwerpen); Toso, Stefano (Istituto Italiano di Tecnologia); Prato, Mirko (Istituto Italiano di Tecnologia); Evers, W.H. (TU Delft BN/Afdelingsbureau); Bals, Sara (Universiteit Antwerpen); Manna, Liberato (Istituto Italiano di Tecnologia); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials)","","2023","Lanthanide-doped LiYF4 (Ln:YLF) is commonly used for a broad variety of optical applications, such as lasing, photon upconversion and optical refrigeration. When synthesized as nanocrystals (NCs), this material is also of interest for biological applications and fundamental physical studies. Until now, it was unclear how Ln:YLF NCs grow from their ionic precursors into tetragonal NCs with a well-defined, bipyramidal shape and uniform dopant distribution. Here, we study the nucleation and growth of ytterbium-doped LiYF4 (Yb:YLF), as a template for general Ln:YLF NC syntheses. We show that the formation of bipyramidal Yb:YLF NCs is a multistep process starting with the formation of amorphous Yb:YLF spheres. Over time, these spheres grow via Ostwald ripening and crystallize, resulting in bipyramidal Yb:YLF NCs. We further show that prolonged heating of the NCs results in the degradation of the NCs, observed by the presence of large LiF cubes and small, irregular Yb:YLF NCs. Due to the similarity in chemical nature of all lanthanide ions our work sheds light on the formation stages of Ln:YLF NCs in general.","Lanthanides; LiYF4; YLF; Ytterbium; Nanocrystals; nucleation and growth; Doping; Phosphors","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:5d894220-3cca-4932-bd0e-86c40503e2e6","http://resolver.tudelft.nl/uuid:5d894220-3cca-4932-bd0e-86c40503e2e6","Estimating large-scale uncertainty in the context of full-waveform inversion","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); Kuvshinov, B. (Shell Global Solutions International B.V.)","","2023","The uncertainty of model parameters obtained by full-waveform inversion can be determined from the hessian of the least-squares error functional. Because the hessian is generally too costly to compute and too large to be stored, a segmented representation of perturbations of the reconstructed subsurface model in the form of geological units is proposed. This enables the computation of the hessian and the related covariance matrix on a larger length scale. A synthetic 2-D isotropic elastic example illustrates how conditional and marginal uncertainties can be estimated for the properties per geological unit by themselves and in relation to other units. A discussion on how the chosen length scale affects the result is included.","","en","conference paper","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:119f1856-8bf6-4fb6-8c6f-d29f0f3bf30a","http://resolver.tudelft.nl/uuid:119f1856-8bf6-4fb6-8c6f-d29f0f3bf30a","Time-shift extended imaging for estimating depth errors","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2023","The stationary-phase method applied to migration with a time-shift extension in a 2-D constant-velocity model with a dipped reflector produces two solutions in the domain of the extended image: one a straight line and the other a curve. If the velocity differs from the true one, the depth error follows from the depth and apparent dip of the reflector as well as the depth of the amplitude peak at a non-zero time shift, where the two solutions meet and the extended image focuses. The results are compared to finite-frequency results from a finite-difference code. A 2-D synthetic example with a salt diapir illustrates how depth errors can be estimated in an inhomogeneous model after inverting the seismic data for the velocity model.","","en","conference paper","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:d96ef936-e7e7-4324-8b1a-050d253569a2","http://resolver.tudelft.nl/uuid:d96ef936-e7e7-4324-8b1a-050d253569a2","A dimensionality reduction approach in helicopter level flight performance testing","Arush, I. (TU Delft Control & Simulation; National Test Pilot School); Pavel, M.D. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","Evaluation of the power required in level flight is essential to any new or modified helicopter performance flight-testing effort. The conventional flight-test method is based on an overly simplification of the induced and profile power components required for a helicopter in level flight. This simplistic approach incorporates several drawbacks that not only make execution of flight sorties inefficient and time consuming, but also compromise the level of accuracy achieved. This paper proposes an alternative flight-test method for evaluating the level-flight performance of a conventional helicopter while addressing and rectifying all identified deficiencies of the conventional method. The proposed method, referred to as the corrected-variables screening using dimensionality reduction (CVSDR), uses an original list of 36 corrected variables derived from basic dimensional analysis principles. This list of 36 corrected variables is reduced using tools of dimensionality reduction to keep only the most effective level-flight predictors. The CVSDR method is demonstrated and tested in this paper using flight-test data from a MBB BO-105 helicopter. It is shown that the CVSDR method predicts the power required for level flight about 21% more accurately than the conventional method while reducing the required flight time by an estimate of at least 60%. Unlike the conventional method, the CVSDR is not bounded by the high-speed approximation associated with the induced power estimation, therefore it is also relevant to the low airspeed regime. This low-airspeed relevancy allows the CVSDR method to bridge between the level-flight regime and the hover. Although demonstrated in this paper for a specific type of helicopter, the CVSDR method is applicable for level-flight performance flight testing of any type of conventional helicopter.","CVSDR; Dimensional Analysis; Helicopter Performance; Keywords:; Level-Flight; SVD","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:dd1eb3ba-71d3-4744-a195-7701b6d14f84","http://resolver.tudelft.nl/uuid:dd1eb3ba-71d3-4744-a195-7701b6d14f84","Autorotation Transfer of Training: Effects of Helicopter Dynamics","Scaramuzzino, P.F. (Politecnico di Milano); Pool, D.M. (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Quaranta, Giuseppe (Politecnico di Milano); Mulder, Max (TU Delft Control & Simulation)","","2023","This paper analyzes the effects of the helicopter dynamics on pilots’ learning process and transfer of learned skills during autorotation training. A quasi-transfer-of-training experiment was performed with ten experienced helicopter pilots in the SIMONA moving-base flight simulator at Delft University of Technology. Pilots had to control an in-house flight dynamics model set up to simulate two types of helicopter dynamics: 1) a “hard” dynamics characterized by a low autorotative flare index requiring high pilot control compensation, and 2) a “easy” dynamics characterized by a high autorotative flare index with low pilot control compensation required. Two groups of pilots tested these types of dynamics in a different training sequence: hard-easy-hard (HEH group) and easy-hard-easy (EHE group). The main conclusion of this study proved that simulator training for autorotation can best start with pilots training in the most resource demanding condition. A more challenging helicopter’s dynamics will require a higher pilot agility and more rapid responses to his/her perceptual changes. This will result in pilots developing more robust and adaptable flying skills. Indeed, a clear positive transfer of training effect was observed in the experiment presented in this paper in terms of acquired pilot skills in the HEH group, but not the EHE group. Positive transfer was especially observed in terms of reduced rate of descent at touchdown. The two groups differed in the control strategy applied, with the HEH group having developed a control technique mimickingmore closely the one adopted in a real helicopter.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-03","","","Control & Simulation","","",""
"uuid:2a91679b-45f9-4851-998b-2ff6bda30efd","http://resolver.tudelft.nl/uuid:2a91679b-45f9-4851-998b-2ff6bda30efd","A mass-based aptasensor for real-time, continuous quantification of TNF-alpha with quartz crystal microbalance","Fasching, L.R. (TU Delft ChemE/Product and Process Engineering); Zhu, P. (TU Delft ChemE/Product and Process Engineering); Mulder, Atticus (Student TU Delft); Beltrao, Gabriel Spiller (Student TU Delft); Neeleman, Yannick (Student TU Delft); Rwei, A.Y. (TU Delft ChemE/Product and Process Engineering)","","2023","Accurate and real-time monitoring of biomarker proteins, such as Tumor Necrosis Factor (TNF) alpha, plays a vital role in early disease diagnosis, effective treatment design, and personalized health management strategies. However, existing detection methods, including enzyme-linked immunosorbent assay (ELISA), radioimmune assays (RIA), and polymerase chain reaction (PCR), have significant drawbacks regarding sensitivity, cost, time, and labor efficiency, emphasizing the urgent need for alternative biosensing techniques. Here, we present a mass-based biosensing approach utilizing aptamers for the real-time detection of proteins, using TNF-alpha as the model analyte. The recognition process is based on the selective binding of the target molecule to the aptamer's unique three-dimensional structure. By utilizing a quartz crystal microbalance (QCM) as the transducing element, real-time detection of target binding is translated into a linear decrease in resonant frequency due to the change in mass upon target binding. The developed aptasensor enabled real-time quantification of TNF-alpha with high reliability, sensitivity, and specificity. The sensitivity of the sensor ranged from 14.5 nM to 115.6 nM, in which a linear correlation between target concentration and frequency decrease rate was found. Successful sensor regeneration demonstrated potential for continuous measurements in solution. By directly monitoring the change in mass during sensor fabrication and upon analyte binding, this platform provides key mechanistic insights in the surface functionalization process during sensor fabrication and analyte binding kinetics during sensor operation. In the future, incorporation of alternative target receptors, by simply changing the aptamer sequence, can broaden the analyte spectrum, making this platform highly versatile. We hereby demonstrate a technology that can be utilized for various biosensing platforms upon minimal modifications, including electrochemical and optical systems, for a wide range of macromolecular analytes.","aptamer-based biosensor; continuous; mass-sensitive aptasensor; real-time cytokine biomarker monitoring","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-04-17","","","ChemE/Product and Process Engineering","","",""
"uuid:9d0dac8c-61df-4d89-8d59-f94664b9e2ff","http://resolver.tudelft.nl/uuid:9d0dac8c-61df-4d89-8d59-f94664b9e2ff","Understanding and Preventing Photoluminescence Quenching to Achieve Unity Photoluminescence Quantum Yield in Yb:YLF Nanocrystals","Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Meijer, M.S. (TU Delft ChemE/Opto-electronic Materials); van Blaaderen, J.J. (TU Delft RST/Luminescence Materials); du Fossé, I. (TU Delft ChemE/Opto-electronic Materials); Jenkinson, Kellie (Universiteit Antwerpen); Bals, Sara (Universiteit Antwerpen); Manna, Liberato (Istituto Italiano di Tecnologia); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials)","","2023","Ytterbium-doped LiYF4 (Yb:YLF) is a commonly used material for laser applications, as a photon upconversion medium, and for optical refrigeration. As nanocrystals (NCs), the material is also of interest for biological and physical applications. Unfortunately, as with most phosphors, with the reduction in size comes a large reduction of the photoluminescence quantum yield (PLQY), which is typically associated with an increase in surface-related PL quenching. Here, we report the synthesis of bipyramidal Yb:YLF NCs with a short axis of 60 nm. We systematically study and remove all sources of PL quenching in these NCs. By chemically removing all traces of water from the reaction mixture, we obtain NCs that exhibit a near-unity PLQY for an Yb3+ concentration below 20%. At higher Yb3+ concentrations, efficient concentration quenching occurs. The surface PL quenching is mitigated by growing an undoped YLF shell around the NC core, resulting in near-unity PLQY values even for fully Yb3+-based LiYbF4 cores. This unambiguously shows that the only remaining quenching sites in core-only Yb:YLF NCs reside on the surface and that concentration quenching is due to energy transfer to the surface. Monte Carlo simulations can reproduce the concentration dependence of the PLQY. Surprisingly, Forster resonance energy transfer does not give satisfactory agreement with the experimental data, whereas nearest-neighbor energy transfer does. This work demonstrates that Yb3+-based nanophosphors can be synthesized with a quality close to that of bulk single crystals. The high Yb3+ concentration in the LiYbF4/LiYF4 core/shell nanocrystals increases the weak Yb3+ absorption, making these materials highly promising for fundamental studies and increasing their effectiveness in bioapplications and optical refrigeration.","core/shell; energy transfer; luminescence; nanocrystals; optical refrigeration; rare earth ions; ytterbium","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:f1aa38df-d38e-42f5-bbc7-459a361bc97a","http://resolver.tudelft.nl/uuid:f1aa38df-d38e-42f5-bbc7-459a361bc97a","Broadband microwave detection using electron spins in a hybrid diamond-magnet sensor chip","Carmiggelt, J.J. (TU Delft QN/vanderSarlab; Kavli institute of nanoscience Delft); Bertelli, I. (TU Delft QN/vanderSarlab; Kavli institute of nanoscience Delft); Mulder, R.W. (TU Delft QN/vanderSarlab; Kavli institute of nanoscience Delft); Teepe, A. (TU Delft QN/vanderSarlab; Kavli institute of nanoscience Delft); Elyasi, Mehrdad (Tohoku University); Simon, B.G. (TU Delft QN/vanderSarlab; Kavli institute of nanoscience Delft); Bauer, G.E. (TU Delft QN/Bauer Group; Tohoku University; Kavli institute of nanoscience Delft); Blanter, Y.M. (TU Delft QN/Blanter Group; Kavli institute of nanoscience Delft); van der Sar, T. (TU Delft QN/vanderSarlab; Kavli institute of nanoscience Delft)","","2023","Quantum sensing has developed into a main branch of quantum science and technology. It aims at measuring physical quantities with high resolution, sensitivity, and dynamic range. Electron spins in diamond are powerful magnetic field sensors, but their sensitivity in the microwave regime is limited to a narrow band around their resonance frequency. Here, we realize broadband microwave detection using spins in diamond interfaced with a thin-film magnet. A pump field locally converts target microwave signals to the sensor-spin frequency via the non-linear spin-wave dynamics of the magnet. Two complementary conversion protocols enable sensing and high-fidelity spin control over a gigahertz bandwidth, allowing characterization of the spin-wave band at multiple gigahertz above the sensor-spin frequency. The pump-tunable, hybrid diamond-magnet sensor chip opens the way for spin-based gigahertz material characterizations at small magnetic bias fields.","","en","journal article","","","","","","","","","","","QN/vanderSarlab","","",""
"uuid:57a266a7-77d4-49db-87d9-c4ddd7028bf9","http://resolver.tudelft.nl/uuid:57a266a7-77d4-49db-87d9-c4ddd7028bf9","Revisiting the Electrochemical Nitrogen Reduction on Molybdenum and Iron Carbides: Promising Catalysts or False Positives?","Izelaar, B. (TU Delft Large Scale Energy Storage); Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Asperti, S. (TU Delft Large Scale Energy Storage); Dugulan, A.I. (TU Delft RID/TS/Instrumenten groep; TU Delft RST/Fundamental Aspects of Materials and Energy); Hendrikx, R.W.A. (TU Delft Team Amarante Bottger); Bottger, A.J. (TU Delft Team Amarante Bottger); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Kortlever, R. (TU Delft Large Scale Energy Storage)","","2023","The electrochemical dinitrogen reduction reaction (NRR) has recently gained much interest as it can potentially produce ammonia from renewable intermittent electricity and replace the Haber-Bosch process. Previous literature studies report Fe- and Mo-carbides as promising electrocatalysts for the NRR with activities higher than other metals. However, recent understanding of extraneous ammonia and nitrogen oxide contaminations have challenged previously published results. Here, we critically assess the NRR performance of several Fe- and Mo-carbides reported as promising by implementing a strict experimental protocol to minimize the effect of impurities. The successful synthesis of α-Mo2C decorated carbon nanosheets, α-Mo2C nanoparticles, θ-Fe3C nanoparticles, and χ-Fe5C2 nanoparticles was confirmed by X-ray diffraction, scanning and transmission electron microscopy, and X-ray photoelectron and Mössbauer spectroscopy. After performing NRR chronoamperometric tests with the synthesized materials, the ammonia concentrations varied between 37 and 124 ppb and are in close proximity with the estimated ammonia background level. Notwithstanding the impracticality of these extremely low ammonia yields, the observed ammonia did not originate from the electrochemical nitrogen reduction but from unavoidable extraneous ammonia and NOx impurities. These findings are in contradiction with earlier literature studies and show that these carbide materials are not active for the NRR under the employed conditions. This further emphasizes the importance of a strict protocol in order to distinguish between a promising NRR catalyst and a false positive.","ammonia; carbide; electrocatalysis; impurities; iron; molybdenum; nitrogen reduction reaction","en","journal article","","","","","","","","","","","Large Scale Energy Storage","","",""
"uuid:35d96ea3-00c0-48bd-98d8-9f4ec96a9bcc","http://resolver.tudelft.nl/uuid:35d96ea3-00c0-48bd-98d8-9f4ec96a9bcc","Tumour-educated platelets for breast cancer detection: biological and technical insights","Liefaard, Marte C. (Netherlands Cancer Institute); Moore, Kat S. (Netherlands Cancer Institute); Mulder, Lennart (Netherlands Cancer Institute); van den Broek, Daan (Netherlands Cancer Institute); Wesseling, Jelle (Netherlands Cancer Institute; Leiden University Medical Center); Sonke, Gabe S. (Netherlands Cancer Institute); Wessels, L.F.A. (TU Delft Pattern Recognition and Bioinformatics; Netherlands Cancer Institute); Rookus, Matti (Netherlands Cancer Institute); Lips, Esther H. (Netherlands Cancer Institute)","","2023","Background: Studies have shown that blood platelets contain tumour-specific mRNA profiles tumour-educated platelets (TEPs). Here, we aim to train a TEP-based breast cancer detection classifier. Methods: Platelet mRNA was sequenced from 266 women with stage I–IV breast cancer and 212 female controls from 6 hospitals. A particle swarm optimised support vector machine (PSO-SVM) and an elastic net-based classifier (EN) were trained on 71% of the study population. Classifier performance was evaluated in the remainder (29%) of the population, followed by validation in an independent set (37 cases and 36 controls). Potential confounding was assessed in post hoc analyses. Results: Both classifiers reached an area under the curve (AUC) of 0.85 upon internal validation. Reproducibility in the independent validation set was poor with an AUC of 0.55 and 0.54 for the PSO-SVM and EN classifier, respectively. Post hoc analyses indicated that 19% of the variance in gene expression was associated with hospital. Genes related to platelet activity were differentially expressed between hospitals. Conclusions: We could not validate two TEP-based breast cancer classifiers in an independent validation cohort. The TEP protocol is sensitive to within-protocol variation and revision might be necessary before TEPs can be reconsidered for breast cancer detection.","","en","journal article","","","","","","correction: the data availability statement was incorrectly given. “EGAS0000100682” should have been “EGAS00001006821”. The original article has been corrected (the pdf file has been changed now)","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:c7de4eee-2c55-49c6-8f44-a19dbb4e49eb","http://resolver.tudelft.nl/uuid:c7de4eee-2c55-49c6-8f44-a19dbb4e49eb","Unisolvence of Symmetric Node Patterns for Polynomial Spaces on the Simplex","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2023","Finite elements with polynomial basis functions on the simplex with a symmetric distribution of nodes should have a unique polynomial representation. Unisolvence not only requires that the number of nodes equals the number of independent polynomials spanning a polynomial space of a given degree, but also that the Vandermonde matrix controlling their mapping to the Lagrange interpolating polynomials can be inverted. Here, a necessary condition for unisolvence is presented for polynomial spaces that have non-decreasing degrees when going from the edges and the various faces to the interior of the simplex. It leads to a proof of a conjecture on a necessary condition for unisolvence, requiring the node pattern to be the same as that of the regular simplex.","Finite elements; Node patterns; Polynomial; Simplex; Unisolvence","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:62bcf04d-0f87-46ae-ad4c-42db203c4f34","http://resolver.tudelft.nl/uuid:62bcf04d-0f87-46ae-ad4c-42db203c4f34","Preventing Scenario Recognition in Human-in-the-Loop Air Traffic Control Research","de Rooij, G. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2023","In academic air traffic control research, traffic scenarios are often repeated to increase the sample size and enable paired-sample comparisons, e.g., between different display variants. This comes with the risk that participants recognize scenarios and consequently recall the desired response. In this paper we provide an overview of mitigation techniques found in literature and conclude that rotating scenario geometries is most frequently used. The potential impact of these transformations on participant behavior, as described in this paper, is however not sufficiently addressed in most studies. As an example we, therefore, analyze previously collected eye tracking data from ten professional air traffic controllers, each presented with three repetitions in various rotations of several distinct scenarios. Results imply that researchers wishing to repeat scenarios should more carefully consider whether mitigation techniques might have an impact on their results.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:6554f955-2b49-445f-97fe-5cc5c77646fe","http://resolver.tudelft.nl/uuid:6554f955-2b49-445f-97fe-5cc5c77646fe","Temporal dispersion correction for wave-propagation modelling with a series approach","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2023","Temporal dispersion correction of second-order finite-difference time stepping for numerical wave propagation modelling exploits the fact that the discrete operator is exact but for the wrong frequencies. Mapping recorded traces to the correct frequencies removes the numerical error. Most of the implementations employ forward and inverse Fourier transforms. Here, it is noted that these can be replaced by a series expansion involving higher time derivatives of the data. Its implementation by higher-order finite differencing can be sensitive to numerical noise, but this can be suppressed by enlarging the stencil. Tests with the finite-element method on a homogeneous acoustic problem with an exact solution show that the method can achieve the same accuracy as higher-order time stepping, similar to that obtained with Fourier transforms. The same holds for an inhomogeneous problem with topography where the solution on a very fine mesh is used as reference. The series approach costs less than dispersion correction with the Fourier method and can be used on the fly during the time stepping. It does, however, require a wavelet that is sufficiently many times differentiable in time.","computing aspects; modelling; seismics; wave","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:c622aa5a-f70c-48d3-825a-a8522670f07d","http://resolver.tudelft.nl/uuid:c622aa5a-f70c-48d3-825a-a8522670f07d","Correction To: Tumour-educated platelets for breast cancer detection: biological and technical insights (British Journal of Cancer, (2023), 128, 8, (1572-1581), 10.1038/s41416-023-02174-5)","Liefaard, Marte C. (Netherlands Cancer Institute); Moore, Kat S. (Netherlands Cancer Institute); Mulder, Lennart (Netherlands Cancer Institute); van den Broek, Daan (Netherlands Cancer Institute); Wesseling, Jelle (Netherlands Cancer Institute; Leiden University Medical Center); Sonke, Gabe S. (Netherlands Cancer Institute); Wessels, L.F.A. (TU Delft Pattern Recognition and Bioinformatics; Netherlands Cancer Institute); Rookus, Matti (Netherlands Cancer Institute); Lips, Esther H. (Netherlands Cancer Institute)","","2023","In this article the data availability statement was incorrectly given. “EGAS0000100682” should have been “EGAS00001006821”. The correct statement as follows. The datasets generated during and/or analysed during the current study are deposited at the European Genome-phenome Archive (EGA) under the accession numbers EGAS00001006821 and EGAD00001009790. The original article has been corrected.","","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:27d19137-42e7-47fc-be6f-df10d78b285b","http://resolver.tudelft.nl/uuid:27d19137-42e7-47fc-be6f-df10d78b285b","A generic approach to parameterize the turbulent energy of single-epoch atmospheric delays from InSAR time-series","Mulder, G. (TU Delft Geoscience and Remote Sensing); van Leijen, F.J. (TU Delft Mathematical Geodesy and Positioning); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning)","","2023","The observed phase in time series of interferometric synthetic aperture radar (InSAR) products is a superposition of various components. Differential topography, line-of-sight displacements, and differential atmospheric delays are the main contributions and need to be disentangled to derive accurate digital elevation model (DEM), deformation, or atmospherical products from InSAR. However, isolating the atmospheric component has been proven difficult as it is spatiotemporally highly dynamic and a superposition of two atmospheric states. Here, we propose an approach to parameterize the stochastic properties of the single-epoch atmospheric delay field as a way to define the atmospheric signal. We found that the atmospheric signal of a time series of interferograms can be characterized by structure functions, which can be used to isolate the single-epoch structure functions. Due to the scaling properties of the atmospheric signal, it is then possible to construct a parametric function per SAR acquisition, using two isotropic and three anisotropic parameters. In particular, the isotropic parameters for the short-distance variation and long-distance variation in atmospheric delay can be used to characterize the atmospheric signal. For a test set of 151 Sentinel-1 acquisitions, this results in an atmospheric energy range of about 10 for short-distance scales and about 50 for long-distance scales. Our parameterization demonstrates that we can describe the spatiotemporal variability of InSAR atmospheric delays, which provides a measure for atmospheric noise for individual epochs in deformation time series based on distance and azimuth.","Atmospheric measurements; Atmospheric modeling; Deformation; Delays; InSAR; Liquids; Meteorology; Periodic structures; tropospheric delay; tropospheric scaling; turbulence","en","journal article","","","","","","","","","","Geoscience and Remote Sensing","Mathematical Geodesy and Positioning","","",""
"uuid:55ae2a99-c385-4029-84b3-584d68d67482","http://resolver.tudelft.nl/uuid:55ae2a99-c385-4029-84b3-584d68d67482","From fear to forecast: The role of simulators, accompanied driving, age, gender, and information-processing style in driver training and beyond","Kuipers, J.R. (TU Delft Control & Simulation; Green Dino BV); de Winter, J.C.F. (TU Delft Cognitive Robotics; TU Delft Human-Robot Interaction); Mulder, Max (TU Delft Control & Simulation)","","2023","Background: Even though accompanied driving and simulator training are common, clarity on their usage trends and effectiveness is lacking. This research aimed to deepen the understanding of the relationships between personal characteristics, pre-licence accompanied driving, self-reported post-licence driving behaviour, and driving performance scores during simulator lessons. Methods: We used data from a questionnaire completed by simulator and non-simulator students (total n = 3,761). Data were analysed by dividing the sample into two groups based on variables such as gender, age at licensure, education level, fear of driving a car when starting driver education, information-processing style, participation in accompanied driving, and the number of driving simulator lessons completed. Results: Males took fewer on-road lessons and reported lower fear, but they had poorer simulator safety scores than females. Younger learners required fewer lessons and test attempts, were less fearful, and violated traffic rules more than older respondents. Higher-educated respondents had more fear and safer driving scores in the simulator. Thinkers, who were typically more educated, showed more caution in the simulator and on the road, and were older at licensure. Compared to regular students, students participating in accompanied driving were younger at licensure. Moreover, students with a higher driving skill score in the simulator were less fearful and needed slightly fewer attempts to pass the road driving test. Discussion and conclusion: The fear towards driving, which is strongly linked to personal characteristics, provides a logical explanation for the progression of students through driver education. Furthermore, this study illustrated the possibility of considering information-processing styles, education level, and driving simulator performance in driving education. However, in order to conclusively study the safety-effectiveness of accompanied driving and simulator training, further research in the form of a randomised controlled trial is necessary.","","en","journal article","","","","","","","","","","Cognitive Robotics","Control & Simulation","","",""
"uuid:0837d31b-08a4-479d-959c-ffd1e79f3ee7","http://resolver.tudelft.nl/uuid:0837d31b-08a4-479d-959c-ffd1e79f3ee7","Polarized Signatures of a Habitable World: Comparing Models of an Exoplanet Earth with Visible and Near-infrared Earthshine Spectra","Gordon, Kenneth E. (University of Central Florida); Karalidi, Theodora (University of Central Florida); Bott, Kimberly M. (University of California; University of Washington); Miles-Páez, Paulo A. (European Southern Observatory); Mulder, W. (Universiteit Leiden); Stam, D.M. (TU Delft Astrodynamics & Space Missions)","","2023","In the JWST, Extremely Large Telescopes, and LUVOIR era, we expect to characterize a number of potentially habitable Earth-like exoplanets. However, the characterization of these worlds depends crucially on the accuracy of theoretical models. Validating these models against observations of planets with known properties will be key for the future characterization of terrestrial exoplanets. Due to its sensitivity to the micro- and macro-physical properties of an atmosphere, polarimetry will be an important tool that, in tandem with traditional flux-only observations, will enhance the capabilities of characterizing Earth-like planets. In this paper we benchmark two different polarization-enabled radiative-transfer codes against each other and against unique linear spectropolarimetric observations of the earthshine that cover wavelengths from ∼0.4 to ∼2.3 μm. We find that while the results from the two codes generally agree with each other, there is a phase dependency between the compared models. Additionally, with our current assumptions, the models from both codes underestimate the level of polarization of the earthshine. We also report an interesting discrepancy between our models and the observed 1.27 μm O2 feature in the earthshine, and provide an analysis of potential methods for matching this feature. Our results suggest that only having access to the 1.27 μm O2 feature coupled with a lack of observations of the O2 A and B bands could result in a mischaracterization of an Earth-like atmosphere. Providing these assessments is vital to aid the community in the search for life beyond the solar system.","","en","journal article","","","","","","","","","","","Astrodynamics & Space Missions","","",""
"uuid:97f2a3cb-f727-4d61-9f73-d30187887f8c","http://resolver.tudelft.nl/uuid:97f2a3cb-f727-4d61-9f73-d30187887f8c","Fault intersection and induced seismicity: the effects on the induced stress field and the dynamic rupture, and their implications","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2023","Intersecting faults are often ignored in the geomechanical simulation of induced seismicity. To investigate the effects of fault intersection and the resulting reservoir geometry on induced seismicity, caused, for instance, by gas extraction, we have developed 3D geomechanical models considering two intersecting normal faults and the surrounding horst structure. We simulate the stress field and the dynamic fault reactivation in a uniformly depleted reservoir. We observe that a smaller intersection angle increases the incremental Coulomb stress at the lower reservoir juxtaposition, thus changing the temporal rupture pattern of the seismic event. In our dynamic simulation, the rupture propagates from the main fault to the secondary fault. We conclude that the fault intersection has important effects on the induced seismicity and should be taken into account when evaluating the seismicity risk in a specific region.","geomechanical modelling; fault intersection; induced seismicty; Groningen gas field; seismic source","en","conference paper","Society of Exploration Geophysicists","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:04db64e6-35fb-4f2d-a27c-9ad5fe9fd9ba","http://resolver.tudelft.nl/uuid:04db64e6-35fb-4f2d-a27c-9ad5fe9fd9ba","Revealing the role of values in developing a garden data ecosystem through a reflective participatory design approach","Cazacu, Silvia (Katholieke Universiteit Leuven); Mulder, I. (TU Delft Design Conceptualization and Communication); Vande Moere, Andrew (Katholieke Universiteit Leuven); Steenberghen, Thérèse (Katholieke Universiteit Leuven)","","2023","Data-driven domains such as public administration, health or mobility have adopted a so-called 'data ecosystem' perspective to unify the socio-technical aspects fostering data-driven collaboration. While a data ecosystem is technically able to collect and merge their different datasets, it is yet relatively unable to facilitate meaningful forms of collaboration between actors. Based on previous research on value creation in data ecosystems, we hypothesize that this inability is mainly due to ecosystems not reflecting actor values, i.e. aspects which are important and imply a desirable behavior, often related to goals, objectives, motivations and decision making. This paper therefore proposes a reflective approach to reveal the values in data-driven collaboration by answering the following research questions: What role do values play in the process of developing a data ecosystem? And how can value-led participatory design support data-driven collaboration? We attempt to answer these questions through an exploratory study based on 5 interviews with consortium members of a garden data ecosystem currently in development around a citizen science initiative in Flanders, Belgium. We discovered that the explicit use of values and frictions has the potential to augment the collaboration between actors. This approach can thus be useful to future practitioners who aim to expand the societal impact of their work.","Citizen science; data ecosystem; data platform; data-driven collaboration; reflective participatory design; values","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:79f075dd-0d0d-4369-b64a-8f258b2f2506","http://resolver.tudelft.nl/uuid:79f075dd-0d0d-4369-b64a-8f258b2f2506","Beyond headcount statistics: Exploring the utility of energy poverty gap indices in policy design","Croon, T.M. (TU Delft Urban Development Management; TNO); Hoekstra, J.S.C.M. (TU Delft Urban Development Management); Elsinga, M.G. (TU Delft Urban Development Management); Dalla Longa, F. (TNO); Mulder, Peter (TNO)","","2023","Recent energy price spikes have led to increased energy poverty among low-income households living in inefficient homes. Accurate statistics on energy poverty help inform resource allocation and better target relief schemes and retrofit funds. Existing indicators are predominantly defined in terms of a headcount ratio – the share of population living below a certain threshold or poverty line. In this paper we draw from the literature on income poverty evaluation to argue that the use of more elaborate energy poverty gap indices can substantiate the design and monitoring of energy poverty policies, by not only considering incidence but also intensity and inequality of energy poverty across households. We demonstrate that the choice for a particular energy poverty (gap) indicator makes the implicit welfare choices of energy poverty policies explicit. We illustrate our arguments for the case of the Netherlands, using recently developed microdata statistics on energy poverty, and an imposed energy price shock. We show that spatial targeting of relief funds based on incidence would neglect the full depth of energy poverty deprivation. Finally, we argue that visualisation techniques from the income poverty literature help to comprehend different poverty orderings and draw comparisons between time periods, regions, and subgroups.","Energy poverty; Energy transition; Fuel poverty; Policy targeting; Poverty gap","en","journal article","","","","","","","","","","","Urban Development Management","","",""
"uuid:073e9bac-2e86-42a6-88f8-1d73757ba616","http://resolver.tudelft.nl/uuid:073e9bac-2e86-42a6-88f8-1d73757ba616","Effect of Temperature and H Flux on the NH3 Synthesis via Electrochemical Hydrogen Permeation","Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Schreuders, H. (TU Delft ChemE/O&O groep); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2023","Ammonia is an indispensable commodity and a potential carbon free energy carrier. The use of H permeable electrodes to synthesize ammonia from N 2, water and electricity, provides a promising alternative to the fossil fuel based Haber-Bosch process. Here, H permeable Ni electrodes are investigated in the operating temperature range 25–120 °C, and varying the rate of electrochemical atomic hydrogen permeation. At 120 °C, a steady reaction is achieved for over 12 h with 10 times higher cumulative NH 3 production and almost 40-fold increase in faradaic efficiency compared to room temperature experiments. NH 3 is formed with a cell potential of 1.4 V, corresponding to a minimum electrical energy investment of 6.6 kWh kg −1 (Figure presented.). The stable operation is attributed to a balanced control over the population of N, NH x and H species at the catalyst surface. These findings extend the understanding on the mechanisms involved in the nitrogen reduction reaction and may facilitate the development of an efficient green ammonia synthesis process.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:f72d2ac8-6d3c-486f-ad64-a692496bb3d7","http://resolver.tudelft.nl/uuid:f72d2ac8-6d3c-486f-ad64-a692496bb3d7","Towards a framework for Open Data literacy in education:: A systematic mapping review of Open Data skills and learning approaches","Vargas, Alejandra Celis (Aalborg University); Magnussen, Rikke (Aalborg University); Mulder, I. (TU Delft Design Conceptualization and Communication); Larsen, Birger (Aalborg University)","","2023","Open Data (OD) is defined as digital data that is made available with the technical and legal characteristics necessary to be freely used, reused, and redistributed by anyone, anytime and anywhere. Although OD can be seen as a commons, citizens often face challenges in accessing, using and making sense of available open datasets. Current literature identifies a lack of data expertise as one of the main barriers and emphasises the importance of strategies for training and teaching the appropriate competencies. Furthermore, a clear definition of OD skills and learning approaches is missed. A two-sided systematic mapping review with a focus on the educational domain was conducted to identify relevant OD skills and the approaches facilitating the development of these competencies. The results section presents a map of OD skills and learning approaches, while the discussion section elaborates on the potential of OD in education to empower students with skills and competencies to better understand their context, act in their everyday life environment and address future challenges. The current contribution is an OD literacy framework that puts OD at the centre of competence-based education, fostering responsible citizenship necessary for addressing today’s societal challenges.","Open Data Education; Open Data skills; Open Data competencies; Open Data literacy; Responsible citizenship; Competence-based education","","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-09-04","","","Design Conceptualization and Communication","","",""
"uuid:3bc42b38-682b-42d4-a565-9dd6a2032582","http://resolver.tudelft.nl/uuid:3bc42b38-682b-42d4-a565-9dd6a2032582","Tuning the Driving Force for Charge Transfer in Perovskite-Chromophore Systems","Wei, Z. (TU Delft ChemE/Opto-electronic Materials); Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Dubey, R. (TU Delft ChemE/Opto-electronic Materials); Evers, W.H. (TU Delft BN/Afdelingsbureau); Jager, W.F. (TU Delft ChemE/Advanced Soft Matter); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials); Grozema, F.C. (TU Delft ChemE/Opto-electronic Materials)","","2023","Understanding the interplay between the kinetics and energetics of photophysical processes in perovskite-chromophore hybrid systems is crucial for realizing their potential in optoelectronics, photocatalysis, and light-harvesting applications. By combining steady-state optical characterizations and transient absorption spectroscopy, we have investigated the mechanism of interfacial charge transfer (CT) between colloidal CsPbBr3 nanoplatelets (NPLs) and surface-anchored perylene derivatives and have explored the possibility of controlling the CT rate by tuning the driving force. The CT driving force was tuned systematically by attaching acceptors with different electron affinities and by varying the bandgap of NPLs via thickness-controlled quantum confinement. Our data show that the charge-separated state is formed by selectively exciting either the electron donors or acceptors in the same system. Upon exciting attached acceptors, hole transfer from perylene derivatives to CsPbBr3 NPLs takes place on a picosecond time scale, showing an energetic behavior in line with the Marcus normal regime. Interestingly, such energetic behavior is absent upon exciting the electron donor, suggesting that the dominant CT mechanism is energy transfer followed by ultrafast hole transfer. Our findings not only elucidate the photophysics of perovskite-molecule systems but also provide guidelines for tailoring such hybrid systems for specific applications.","","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:92bbefb4-0fc8-4edf-bbb7-073e2df49ec9","http://resolver.tudelft.nl/uuid:92bbefb4-0fc8-4edf-bbb7-073e2df49ec9","Identification, Quantification, and Elimination of NOx and NH3 Impurities for Aqueous and Li-Mediated Nitrogen Reduction Experiments","Izelaar, B. (TU Delft Large Scale Energy Storage); Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); van Noordenne, D.D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Jungbacker, M.P. (TU Delft ChemE/Materials for Energy Conversion and Storage); Kortlever, R. (TU Delft Large Scale Energy Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2023","","","en","journal article","","","","","","","","","","","Large Scale Energy Storage","","",""
"uuid:4a5b50ab-ac84-4699-babf-0638a2ebb03e","http://resolver.tudelft.nl/uuid:4a5b50ab-ac84-4699-babf-0638a2ebb03e","Adaptive Manual Control: a Predictive Coding Approach","Terenzi, L. (Student TU Delft); Zaal, P.M.T. (NASA Ames Research Center); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2022","Improved understanding of human adaptation can be used to design better (semi-)automated systems that can support the human controller when task characteristics suddenly change. This paper evaluates the effectiveness of a model-based adaptive control technique, Model Reference Adaptive Control (MRAC), for describing the adaptive control policy used by human operators while controlling a time-varying system in a pursuit-tracking task. Ten participants took part in an experiment in which they controlled a time-varying system whose dynamics changed twice between approximate single and double integrator dynamics, and vice versa. Our proposed MRAC controller is composed of a feedforward and a feedback controller and an internal reference model that is used to drive an adaptive control policy. MRAC's adaptive control gains, the internal model parameters, and the learning rates were estimated from the experiment data using non-linear optimization aimed at maximizing the quality-of-fit of participants' control outputs. Participants' control behavior rapidly changed when the dynamics of the controlled system changed, in particular for transitions from single to double integrator dynamics. The MRAC model was indeed able to accurately capture the transient dynamics exhibited by the participants when the system changed from an approximate single to a double integrator, however, for the opposite transition the MRAC gains were always adapted too slowly. Therefore, in its current form, our MRAC model can be used to approximate human adaptation in pursuit tracking tasks when a change in the dynamics of the controlled system requires significant (rate) feedback controller adaptation to maintain satisfactory closed-loop control performance.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:c2f8284e-306a-4f0a-bcf1-bdbcac922902","http://resolver.tudelft.nl/uuid:c2f8284e-306a-4f0a-bcf1-bdbcac922902","Impact of random variation in albuminuria and estimated glomerular filtration rate on patient enrolment and duration of clinical trials in nephrology","Waijer, Simke W. (Rijksuniversiteit Groningen); Provenzano, Michele (Second University of Naples); Mulder, S.T. (TU Delft Pattern Recognition and Bioinformatics; Rijksuniversiteit Groningen); Rossing, Peter (Steno Diabetes Centre Copenhagen; University of Copenhagen); Persson, Frederik (Steno Diabetes Centre Copenhagen); Perkovic, Vlado (University of New South Wales); Heerspink, Hiddo J.L. (Rijksuniversiteit Groningen; University of New South Wales)","","2022","Aim: To test whether a screening approach with more flexible urinary albumin creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) thresholds would decrease screen failure rate without negatively impacting on the event rate and overall study duration. Methods: We performed a post-hoc analysis of the ALTITUDE trial. We selected participants randomized to placebo with a UACR of >300 mg/g and an eGFR between 30 mL/min/1.73 m2 and 60 mL/min/1.73 m2 at the first visit (pre-screening) for the trial. We then used less stringent lower UACR and higher eGFR thresholds for the following qualifying visit. For each scenario we calculated the number of eligible participants, the number of renal and cardiovascular endpoints, and the event rates. Based on this, we performed simulations for a future trial and estimated the duration of enrolment and total duration of this trial. Results: The base scenario consisted of 848 participants (median UACR 1239 mg/g; median eGFR 44 mL/min/1.73 m2). Lowering the UACR and/or raising eGFR qualification thresholds increased the number of eligible participants, decreased screen failures and resulted in only a modest decrease in renal and cardiovascular event rates. For example, relaxing the UACR criterion from 300 mg/g to 210 mg/g at the qualifying visit, increased the number of eligible patients from 848 to 923, and increased the number of renal events from 117 to 122 events. The event rate showed a moderate decrease from 5.6 (4.6-6.7) events per 100 patient-years to 5.3 (4.4-6.4) events per 100 patient-years. In simulations, lowering the UACR and raising eGFR thresholds for inclusion accelerated patient enrolment and did not increase in the overall trial duration. Conclusion: More flexible albuminuria and eGFR-based inclusion criteria, in participants who met the inclusion criteria of a trial based on pre-screening values prior to the clinical trial, decreases screen failure rates and accelerated patient enrolment leading to more efficient trial conduct without impacting the overall trial duration.","albuminuria; chronic kidney disease; clinical trial design; eGFR; screen failure","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:6b7844fc-601a-42b3-96a0-b64d15f4b9c6","http://resolver.tudelft.nl/uuid:6b7844fc-601a-42b3-96a0-b64d15f4b9c6","Operando isotope selective ammonia quantification in nitrogen reduction studies via gas chromatography-mass spectrometry","Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Zaffaroni, R. (TU Delft ChemE/Materials for Energy Conversion and Storage); Kolen, M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Middelkoop, J. (TU Delft ChemE/O&O groep); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2022","Rapid advances in electrocatalytic ammonia synthesis are impeded by laborious detection methods commonly used in the field and by constant risk of external contaminations, which generates misleading false positives. We developed a facile real-time GC-MS method for sensitive isotope NH3 quantification, requiring no external sample manipulations. This method ensures high detection reliability paramount to accelerate (electro-)catalyst screening.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:e8d7dd04-0bbf-452a-89f1-63ab8d9ed83d","http://resolver.tudelft.nl/uuid:e8d7dd04-0bbf-452a-89f1-63ab8d9ed83d","Imagining digital twins in healthcare: Designing for values as designing for technical milieus","de Boer, Bas (University of Twente); Strasser, C. (Student TU Delft); Mulder, S.S. (TU Delft Methodologie en Organisatie van Design)","","2022","Medicine is increasingly focusing on the prevention of diseases. The digital twin (DT) is considered to be an important technological development for realizing this transition. Broadly speaking, a DT is an in silico representation of an individual that dynamically reflects molecular and physiological status, which makes it possible to monitor precisely health status over time. Currently, DTs are more of an abstract ideal than a concrete technological reality, which makes it possible to actively imagine the different ways in which DTs might materialize. This article develops an approach to imagining the different ways in which DTs can be integrated into the lives of people. It focuses on how potential users want to be cared for by means of DTs and how care practices might be changed through the introduction of DTs. The article shows that a shift towards preventive medicine is taking place and situates DT in this context. Then, drawing on the insights of Gilbert Simondon, it suggests that the notion of technical milieu can be a helpful tool for designers to imagine the practices of valuing to which DTs give rise. Subsequently, it explains how our philosophical approach helps inform what kinds of DTs can be imagined. Then, based on interviews with people likely to relate to DTs in the (near) future, it develops six conceptions of DTs and fleshes out some of the implications of our approach for the design of DTs.","","en","journal article","","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:b8eb71f4-8888-4346-9394-b984e380ed99","http://resolver.tudelft.nl/uuid:b8eb71f4-8888-4346-9394-b984e380ed99","Overcoming Nitrogen Reduction to Ammonia Detection Challenges: The Case for Leapfrogging to Gas Diffusion Electrode Platforms","Kolen, M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Smith, W.A. (TU Delft ChemE/Materials for Energy Conversion and Storage); Burdyny, T.E. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2022","The nitrogen reduction reaction (NRR) is a promising pathway toward the decarbonization of ammonia (NH3) production. However, unless practical challenges related to the detection of NH3 are removed, confidence in published data and experimental throughput will remain low for experiments in aqueous electrolyte. In this perspective, we analyze these challenges from a system and instrumentation perspective. Through our analysis we show that detection challenges can be strongly reduced by switching from an Hcell to a gas diffusion electrode (GDE) cell design as a catalyst testing platform. Specifically, a GDE cell design is anticipated to allow for a reduction in the cost of crucial 15N2 control experiments from €100−2000 to less than €10. A major driver is the possibility to reduce the 15N2 flow rate to less than 1 mL/min, which is prohibited by an inevitable drop in mass-transport at low flow rates in H-cells. Higher active surface areas and improved mass transport can further circumvent losses of NRR selectivity to competing reactions. Additionally, obstacles often encountered when trying to transfer activity and selectivity data recorded at low current density in Hcells to commercial device level can be avoided by testing catalysts under conditions close to those in commercial devices from the start.","ammonia; detection; nitrogen reduction; gas diffusion electrode; catalyst","en","review","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:52e2fb79-e3c7-4083-85c2-27add899cae1","http://resolver.tudelft.nl/uuid:52e2fb79-e3c7-4083-85c2-27add899cae1","Serious Games for Building Data Capacity","Di Staso, D. (TU Delft Design Conceptualization and Communication); Mulder, I. (TU Delft Design Conceptualization and Communication); Janssen, M.F.W.H.A. (TU Delft Information and Communication Technology); Kleiman, F. (NHL Stenden University of Applied Sciences)","","2022","Open data can support the creation of new services, facilitate research, and provide insights into everyday issues affecting citizens. Although public administrations are making efforts to create sustainable and inclusive open data systems, there is limited capacity to identify suitable datasets, clean, release, and reuse them. Serious games offer a possible solution for data capacity building and have already been used to train civil servants and citizens on the topic of open data. This research presents a review of serious games and discusses their potential for data capacity building. The games selected in the review are classified and described according to their different learning outcomes, formats, and type of media. Most serious games found in this review can be categorized as teaching games and are designed to raise data awareness, which is only a limited aspect of building data capacity. We found a lack of design games, research games, and policy games. Given their success for ideation in other fields, design games offer a particular opportunity to build data capacity by generating new ideas about how to reuse open datasets.","data capacity; open data; serious games","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:17754670-2f32-4556-8a81-8056b7832fcc","http://resolver.tudelft.nl/uuid:17754670-2f32-4556-8a81-8056b7832fcc","Linking geomechanical simulation of induced seismicity to surface seismic observations: Simulated finite fault rupture to moment tensor inversion","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Masfara, La ODE Marzujriban (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (Shell Global Solutions International B.V.)","","2022","Dynamic geomechanical modeling can generate the seismic wavefield caused by a fault rupture. In dynamic fault-rupture modeling, the source is considered to be finite, with a limited extent both in space and in time. This contrasts with the definition of a point source, which is generally assumed to explain the seismic wavefield caused by an earthquake. Most earlier seismic inversion studies, including those of the induced earthquakes caused by depletion of the Groningen gas field, were performed assuming a point source. Still, finding a point-source reference from the seismic wavefield, even when generated by finite faulting, is important in order to calibrate the geomechanical simulation with field-seismic observations. To this end, we have developed a workflow that links geomechanical forward modeling to seismic moment-tensor inversion. We have tested this workflow for the dynamic rupture considering a realistic 3D layered earth model. At first, we simulate the triggering of dynamic fault slip at the center of a fault plane. Next, we invert the seismograms recorded by receivers located on or near the surface to obtain the full moment-tensor point-source representation and the location of the earthquake. The results of inversion show similar waveforms for both the point source and the finite source. The location of the inverted point source is within 400 m from the center of the slip patch. The double-couple components of the inverted moment tensor also match with the strike and the dip of the fault plane.","geomechanical modeling; seismic inversion; Induced seismicity; Groningen gas field; finite source","en","book chapter","Society of Exploration Geophysicists","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:d8132c0d-cb6e-4186-98a9-5a9c42f0bd62","http://resolver.tudelft.nl/uuid:d8132c0d-cb6e-4186-98a9-5a9c42f0bd62","Efficiency of Old and New Triangular Finite Elements for Wavefield Modelling in Time","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2022","Finite elements with mass lumping allow for explicit time stepping when modelling wave propagation and can be more efficient than finite differences in complex geological settings. In 2D on quadrilaterals, spectral elements are the obvious choice. Triangles are more flexible for meshing, but the construction of polynomial elements is less straightforward. So far, elements up to degree 9 have been found. Some years ago, an accuracy criterion that is sharper and less restrictive than the customary one led to new tetrahedral elements that are considerably more efficient than those previously known. Applying the same criterion to triangular elements provides infinitely many new elements of degree 5, with the same number of nodes as the old one, and two elements of degree 6 with less nodes than the known ones. Their efficiency, measured in terms of the compute time needed to obtain a solution with a given accuracy, is determined for a homogeneous problem and compared to that of the old elements of degree 1 to 8. For moderate accuracy, elements of degree 3 are the most efficient. For high accuracy, one of the new degree-6 elements performs best.","","en","conference paper","European Association of Geoscientists and Engineers","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:2d159f93-0e61-4acc-a3c9-3178a7588360","http://resolver.tudelft.nl/uuid:2d159f93-0e61-4acc-a3c9-3178a7588360","3D geomechanical modelling of induced seismicity: Simulated finite-source to moment tensor inversion","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Masfara, La ODE Marzujriban (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2022","","","en","abstract","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:d198b488-7b35-42d4-9bef-00f51b34e343","http://resolver.tudelft.nl/uuid:d198b488-7b35-42d4-9bef-00f51b34e343","High-order homogenization for simulating local effects of small-scale structures on seismic waves","Cupillard, Paul (Lorraine University); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2022","","","en","abstract","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:c9a49b2e-813c-456c-a167-d00152b3148b","http://resolver.tudelft.nl/uuid:c9a49b2e-813c-456c-a167-d00152b3148b","Design and engineering as agents of change: a capabilities framework: a capabilities framework","Mulder, I. (TU Delft Design Conceptualization and Communication); Magni, A. (TU Delft Design Conceptualization and Communication)","Bohemia, Erik (editor); Buck, Lyndon (editor); Grierson, Hilary (editor)","2022","Design is generally accepted to provide valuable contributions to addressing complex societal challenges. Even though design and engineering professionals show increasingly capable of making societal impact, it is not straightforward why some creative practices are more impactful in fostering systemic change, let alone what additional capabilities they pursue to be distinctive. The current study introduces a capabilities framework highlighting a set of advanced design capabilities expanding the conventional skillset of designers and engineers towards enabling the adoption of local innovation at a systemic scale. Afterwards, the developed capabilities framework is used as a pedagogical framework
to design a learning environment to prepare the next generation of design and engineering students to respond to today’s societal challenges. We close with a discussion on the professional and pedagogic role of design and engineering as agents of change","design capabilities; disruption; regeneration; societal challenges; urban transformation","en","conference paper","The Design Society","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:460aeaca-ec24-4682-a3a0-cb1a68013be5","http://resolver.tudelft.nl/uuid:460aeaca-ec24-4682-a3a0-cb1a68013be5","Towards a Power-Balanced Participatory Design Process","Tomasini Giannini, F. (Student TU Delft); Mulder, I. (TU Delft Design Conceptualization and Communication)","Vlachokyriakos, Vasilis (editor); Yee, Joyce (editor); Frauenberger, Christopher (editor); Hurtado, Melisa Duque (editor); Hansen, Nicolai (editor); Strohmayer, Angelika (editor); Van Zyl, Izak (editor); Dearden, Andy (editor); Talhouk, Reem (editor); Gatehouse, Cally (editor); Leishman, Donna (editor); Agid, Shana (editor); Sciannamblo, Mariacristina (editor); Taylor, Jennyfer (editor); Botero, Andrea (editor); Del Gaudio, Chiara (editor); Akama, Yoko (editor); Clarke, Rachel (editor); Vines, John (editor)","2022","Participatory designers have taken inspiration from other practices like the social sciences to develop socially just and horizontal processes to collaborate with communities. In the current work, we take the premise that designers do not have enough means to address concepts of power and politics in design practice. Therefore, we elaborate upon how designers could develop horizontal
relationships within participatory design practices. Informed by the legacy of Paulo Freire, a research-through-design study exploring new ways of engaging and interacting with the community has been conducted. The study setup allowed for reflection upon the changing role of the designer in a community context. We conclude with a series of propositions and discuss their contribution to power-balanced relationships in participatory design processes.","Dialogical Spaces; Liberation; Participatory Design; Power Dynam- ics; Praxis; Reflection; Social Justice","en","conference paper","Association for Computer Machinery","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:e70bf304-fbd9-4af2-9609-2af45a4b71e9","http://resolver.tudelft.nl/uuid:e70bf304-fbd9-4af2-9609-2af45a4b71e9","Dynamic Digital Twin: Diagnosis, Treatment, Prediction, and Prevention of Disease During the Life Course","Mulder, S.T. (TU Delft Pattern Recognition and Bioinformatics); Omidvari, Amir-Houshang (Erasmus MC); Rueten-Budde, A.J. (Erasmus MC); Hai, R. (TU Delft Web Information Systems); Akgün, O.C. (TU Delft Bio-Electronics); Tax, D.M.J. (TU Delft Pattern Recognition and Bioinformatics); Reinders, M.J.T. (TU Delft Pattern Recognition and Bioinformatics); Reinders, Marcel (TU Delft Pattern Recognition and Bioinformatics); Visch, V.T. (TU Delft Design Aesthetics)","","2022","A digital twin (DT), originally defined as a virtual representation of a physical asset, system, or process, is a new concept in health care. A DT in health care is not a single technology but a domain-adapted multimodal modeling approach incorporating the acquisition, management, analysis, prediction, and interpretation of data, aiming to improve medical decision-making. However, there are many challenges and barriers that must be overcome before a DT can be used in health care. In this viewpoint paper, we build on the current literature, address these challenges, and describe a dynamic DT in health care for optimizing individual patient health care journeys, specifically for women at risk for cardiovascular complications in the preconception and pregnancy periods and across the life course. We describe how we can commit multiple domains to developing this DT. With our cross-domain definition of the DT, we aim to define future goals, trade-offs, and methods that will guide the development of the dynamic DT and implementation strategies in health care.","artifical intelligence; cardiovascular; digital health; digital twin; disease; health; machine learning; obstetrics","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:39103f30-c111-4bb6-8b46-2434a0cf4d9a","http://resolver.tudelft.nl/uuid:39103f30-c111-4bb6-8b46-2434a0cf4d9a","Automatic Control of Hot Metal Temperature","Hashimoto, Y. (JFE Steel Corporation); Masuda, Ryosuke (JFE Steel Corporation); Mulder, Max (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2022","To achieve the automation of blast furnace operation, an automatic control system for hot metal temperature (HMT) was developed. Nonlinear model predictive control (NMPC) which predicts up to ten-hour-ahead HMT and calculates appropriate control actions of pulverized coal rate (PCR) was constructed. Simulation validation showed that the NMPC algorithm generates control actions similar to those by the operators and that HMT can be maintained within ±10 °C of the set point. The automatic control system using NMPC was then implemented in an actual plant. As a result, the developed control system suppressed the effects of disturbances, such as the changes in the coke ratio and blast volume, and successfully reduced the average control error of HMT by 4.6 °C compared to the conventional manual operation. The developed control system has contributed to the reduction of reducing agent rate (RAR) and CO2 emissions.","blast furnace; process control; reducing agent rate; thermal control","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:4630a71e-e3e7-4273-97ce-b0a4687b97fb","http://resolver.tudelft.nl/uuid:4630a71e-e3e7-4273-97ce-b0a4687b97fb","3D geomechanical modelling of induced seismicity: finite source wavefield simulation to moment tensor inversion","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Masfara, La ODE Marzujriban (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2022","Geomechanical modelling is generally used to simulate the nucleation of induce d earthquakes in, for instance the Groningen gas field. We apply quasi static simulation to investigate the stress changes from gas production. When a fault reaches a critical state, dynamic simulation provides information on the dynamic rupture during ea rthqu ake nucleation and the resulting wavefield . With the use of geomechanical modelling, it is possible to investigate the effects of the model parameters, e.g., depletion pattern and friction parameters. I n the modelling, the dynamic rupture at a finite fault is simulated both in space and time. The generated seismic wavefield from such a finite source is considered to be more realistic than the resulting wavefield from a point source. T he latter is often assumed in previous studies on the inversion of in duced earthquake data in the Groningen area. To link the wavefield generated by a geomechanically simulated finite source to the field seismic data for an earlier earthquake, we apply the same full moment tensor inversion to the waveform of a finite and of a point source . The inverted moment tensor from the field seismic observation provides a constraint to our geomechanical simulation. This allows us to perform a more realistic simulation of an induced earthquake.","","en","poster","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:8b646b74-5416-48ba-b20b-5dc082fb22d5","http://resolver.tudelft.nl/uuid:8b646b74-5416-48ba-b20b-5dc082fb22d5","Reducing Motion Sickness by Manipulating an Autonomous Vehicle's Accelerations","Wijlens, R. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); Takamatsu, Atsushi (Nissan Motor Co., Ltd.); Makita, Mitsuhiro (Nissan Motor Co., Ltd.); Wada, Takahiro (Nara Institute of Science and Technology)","","2022","Without intervention the widespread adoption of autonomous vehicles could be compromised by an increased incidence of motion sickness compared to conventional cars. To investigate whether passengers' motion sickness can be reduced by manipulating an autonomous vehicle's accelerations on a fixed route without altering the travel time, a human-out-of-the-loop experiment was performed in the SIMONA Research Simulator at Delft University of Technology. The experiment consisted of two different driving conditions, in which an identical 22-km road including 52 curves was travelled in 30 minutes. Condition 1 comprised larger longitudinal, but smaller lateral, acceleration values compared to Condition 2. Experimental results suggested that Condition 1 resulted in more severe motion sickness than Condition 2, with fitted learning curves providing final MIsery SCale scores of 1.19 vs. 0.80. A similar relative difference between the two conditions had been predicted by the 6-DOF Subjective Vertical Conflict model. Hence, this model has the potential to, once further developed, support the design of autonomous vehicles by reducing the need to perform costly, time-consuming experiments.","autonomous vehicles; driving; mitigation; modeling; motion sickness","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:6cca46e6-d492-4b41-b5ef-4649714499c9","http://resolver.tudelft.nl/uuid:6cca46e6-d492-4b41-b5ef-4649714499c9","Cybernetic Data Augmentation for Neural Network Classification of Control Skills","de Jong, M.A. (TU Delft Electrical Engineering, Mathematics and Computer Science); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2022","Mathematical human controller (HC) models are widely used in tuning manual control systems and for understanding human performance. Typically, quasi-linear HC models are used, which can accurately capture the linear portion of HCs' behavior, averaged over a long measurement window. This paper presents a deep learning HC skill-level evaluation method that works on short windows of raw HC time signals, and accounts for both the linear and non-linear portions of HC behavior. This deep learning approach is applied to data from a previous skill training experiment performed in the SIMONA Research Simulator at TU Delft. Additional human control data is generated using cybernetic HC model simulations. The results indicate that the deep learning evaluation method is successful in predicting HC skill level with 85-90% validation accuracy, but that training the classifier solely on simulated HC data reduces this accuracy by 15-25%. Inspection of the results especially shows a strong sensitivity of the classifier to the presence of remnant in the simulated training data. In conclusion, these results reveal that current quasi-linear HC model simulations, and in particular the remnant portion, do not adequately capture real time-domain HC behavior to allow effective training-data augmentation.","classification; control skills; Cybernetics; manual control; neural networks","en","journal article","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","Control & Simulation","","",""
"uuid:a2d4e771-88ae-4255-bf65-3997c1d14d1d","http://resolver.tudelft.nl/uuid:a2d4e771-88ae-4255-bf65-3997c1d14d1d","Situation Awareness Prompts: Bridging the Gap between Supervisory and Manual Air Traffic Control","Kim, Munyung (Student TU Delft); Borst, C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2022","To meet increasing safety and performance demands in air traffic control (ATC), more advanced automated systems will be introduced to assist human air traffic controllers. Some even foresee complete automation, with the human as a supervisor only to step-in when automation fails. Literature and empirical evidence suggest that supervising highly-automated systems can cause severe vigilance and complacency problems, out-of-the-loop situation awareness and transient workload peaks. These impair the ability for humans to successfully take over control. In this study, situation awareness prompts were used as a way to keep controllers cognitively engaged during their supervision of a fully automated ATC system. Results from an exploratory human-in-the-loop experiment, in which eight participants were instructed to monitor a fully automated ATC system in a simplified ATC context, show a significant decrease in workload peaks following an automation failure after being exposed to high-level SA questions. Although the selected method did not necessarily yield improved safety and manual control efficiency, results suggest that using situation awareness feedback in line with controllers' attention could be an avenue worth exploring further as a training tool.","cooperation; Decision making and cognitive processes; degree of automation; Human centred automation; Shared control","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:05096f26-30f1-4cfc-8e7e-74dccaa3659f","http://resolver.tudelft.nl/uuid:05096f26-30f1-4cfc-8e7e-74dccaa3659f","Neuroscience Perspectives on Adaptive Manual Control with Pursuit Displays","Mulder, Max (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van der El, Kasper (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2022","Cyberneticists develop mathematical human control models which are used to tune manual control systems and understand human performance limits. Neuroscientists explore the physiology and circuitry of the central nervous system to understand how the brain works. Both research human visuomotor control tasks, such as the pursuit tracking task. In this paper we discuss some commonalities and differences in both approaches to better understand the adapting human controller. Special attention is given to Adaptive Model Theory, which studied adaptive human control using several linear and nonlinear control engineering techniques. The insights gained yield schemes and concepts which pave the way for key future work on this topic.","Adaptive system and control; Manual Control; Modeling of human performance","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:6a120d64-bf41-41f4-872c-bc9e3947e4c7","http://resolver.tudelft.nl/uuid:6a120d64-bf41-41f4-872c-bc9e3947e4c7","Identifying Human Preview Control Behavior Using Subsystem Identification","Bentinck, Pieter Bas J.C. (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); van der El, Kasper (TU Delft Control & Simulation); Hoagg, Jesse B. (University of Kentucky); Mulder, Max (TU Delft Control & Simulation)","","2022","Better understanding of manual control requires more research on human anticipatory feedforward behaviour. Recent advances include a human control model for preview tracking, and a subsystem identification (SSID) technique that uses a candidate pool approach to identify the human feedforward and feedback responses. This paper discusses the performance of the SSID method when estimating the preview control model parameters. Through simulations of a preview task with two controlled element dynamics, the SSID performance with different remnant noise levels and candidate pool densities is quantified. We demonstrate its successful application to the preview model and show that its performance deteriorates for higher noise levels. While the feedforward parameters are estimated accurately, the high-frequency compensatory feedback dynamics cannot be reliably determined. Future work focuses on alternative formulations for using SSID to estimate preview model parameters. Since in manual control the closed-loop magnitude decreases at higher frequencies, effects of manipulating the weightings of the closed-loop fitting cost values at these frequencies must be further analyzed.","Modeling of HMS; Modeling of human performance","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:e1b83880-a2ea-472c-9a0b-6d2b92b294ce","http://resolver.tudelft.nl/uuid:e1b83880-a2ea-472c-9a0b-6d2b92b294ce","Towards Human-Automation Teamwork in Shared En-Route Air Traffic Control: Task Analysis","de Rooij, G. (TU Delft Control & Simulation); Tisza, A. B. (EUROCONTROL); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","Kaber, David (editor); Guerrieri, Antonio (editor); Fortino, Giancarlo (editor); Nurnberger, Andreas (editor)","2022","In the quest for more efficient air traffic management, a common approach is to allocate an increasing amount of functionality to higher levels of automation, with a supervisory role for humans. This potentially leads to forthcoming issues such as skill degradation and out-of-the-loop phenomenon. If the traffic in an airspace is instead shared between a human operator and an automated system, with specific flights fully delegated to automation, operators can maintain their skills and stay actively involved in controlling the rest of the traffic. This does, however, lead to new forms of mixed conflicts, where two flights are controlled by different agents. A smart flight allocation strategy, starting with the delegation of basic flights requiring little monitoring or cognitive effort, is expected to improve combined human-automation performance. In this paper, we present flowcharts to model en-route air traffic controller cognitive think and action processes in two core tasks: conflict detection and resolution. We qualitatively describe the impact of delegating flights to automation and the associated introduction of mixed conflicts. Once empirically validated and quantified in follow-up research, these models can be used to design flight allocation strategies for future human-automation teams.","Air traffic control; Human-automation teamwork; Task analysis","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Control & Simulation","","",""
"uuid:2027ed55-c4a7-4c3b-ae58-44637f6d7a8a","http://resolver.tudelft.nl/uuid:2027ed55-c4a7-4c3b-ae58-44637f6d7a8a","Motion Cueing Quality Comparison of Driving Simulators using Oracle Motion Cueing","Kolff, M.J.C. (TU Delft Control & Simulation; BMW Group); Venrooij, Joost (BMW Group); Schwienbacher, Markus (BMW Group); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2022","BMW’s new driving simulation center operates multiple motion-base simulators – each with a different kinematic configuration – to serve various experiment use-cases and requirements of simulator users. The selection of a simulator for each experiment should ideally be based on their relative strengths and weaknesses. To support this decision-making process, subjective and objective predictions of motion cueing quality can be used. This paper provides an example comparison of four motion-base driving simulators. The kinematic configurations of the simulators considered differed in the additional presence of a yaw-drive and/or a linear xy-drive. The comparison is made by calculating offline, optimization-based motion cueing with perfect prediction capabilities (the ‘Oracle’) for nine urban drives. A prediction of subjective motion incongruence ratings is made for each simulator. In addition, an error type identification method is used (identifying scaling, missing cue, false cue and false direction cue errors) and evaluated per simulator. As Oracle can fully utilize the available workspace, the employed evaluation methods provide an insight in the fundamental capabilities of each simulator. Both the modelled ratings and the error type analysis show the benefits of adding a xy-drive in urban use-cases: predicted ratings reduce by 19% (i.e., better), while scaling and missing cue errors in the yaw rate are reduced when adding a yaw-drive. The presence of both of these additional motion systems allow for practically one-to-one and therefore error-free motion cueing. The proposed methods provide a straight-forward, yet insightful basis for simulator selection. The presented methods can be extended towards the analysis of multiple motion cueing algorithms and/or other usecases for systematically selecting the best-suited motion cueing method.","Motion cueing; simulator comparison; quality comparison; objective assessment","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:289f4015-d4b0-4c6f-b642-1f6d8085c5c9","http://resolver.tudelft.nl/uuid:289f4015-d4b0-4c6f-b642-1f6d8085c5c9","Predicting Human Control Adaptation from Statistical Variations in Tracking Error and Error Rate","van Ham, Jacomijn M. (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2022","This paper presents the results of an experiment that was performed to verify the 'supervisory control algorithm', a well-known model of human operator adaptation to changes in controlled element dynamics. This model proposes that human adaptive behavior is triggered once the magnitudes of the tracking error or error rate exceed certain decision region limits. In the experiment, a compensatory tracking task with a sudden transition in the controlled element dynamics, as also tested in other recent experiments, was performed by six skilled participants. In addition to performing the control task, participants had to indicate with a button press when they detected a controlled element transition. The results indicate that the published detection limits for the 'supervisory control algorithm' are too conservative for our experiment data, as measured detections could be related to error or error rate occurrences that exceeded 2-6 times their respective pre-transition standard deviations. The effectiveness of new detection limits proportional to these pre-transition standard deviations was tested. The best match to our experiment data was obtained with limits at 3.9σ, for which in only 9.38% and 11.5% of cases a (false positive) too early detection or a (false negative) missed detection occurred, respectively. Overall, these results demonstrate that human operator adaptation can indeed be effectively predicted from statistical variations in tracking error and error rate.","Cybernetics; human operator adaptation; manual control; time-varying behavior","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:b7c5a34d-4dfa-4484-8869-ee5edda4ea84","http://resolver.tudelft.nl/uuid:b7c5a34d-4dfa-4484-8869-ee5edda4ea84","Human Performance in Solving Multi-UAV Over-Constrained Dynamic Vehicle Routing Problems","Gupta, Ankit (Student TU Delft); Borst, C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2022","For many logistics applications, such as drone delivery missions, finding an optimized network of routes yields a Vehicle Routing Problem (VRP). Such optimizations are mostly conducted offline prior to actual operations for reasons of computational complexity. In case disturbances arise during operations, for example a sudden loss of a vehicle, the VRP needs to be re-optimized in real-time and this raises concerns regarding obtaining a solution within time. In a previous study, it was demonstrated that humans, when supported through a human-machine interface, can quickly deal with these routing problems through satisficing, providing workable solutions. This paper extends our previous research by exposing human operators to an over-constrained VRP with different mission priorities and vehicle capabilities. Experiment results (n = 16) indicate that the mission type had the largest impact on how participants used the interface and what constraints were relaxed. In particular, during a search-and-rescue context the mission emphasis was put on delivering (medical) payload (close) to as many customers as possible, even if this would involve sacrificing vehicles and relaxing the depot constraint. Ethical aspects of the VRP are taken into account which algorithms do not by themselves, underlining the importance of involving humans in automation. Human operators complement algorithms with their context awareness, yielding more safe, resilient and responsible systems.","cognitive processes; Decision making; Human operator support","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:2ec5f54a-6d12-434b-8035-973561e83d85","http://resolver.tudelft.nl/uuid:2ec5f54a-6d12-434b-8035-973561e83d85","Probabilistic Perspective on Compensatory, Pursuit and Preview Manual Control","Mulder, Max (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van der El, Kasper (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2022","Mathematical human control models are widely used in tuning manual control systems and understanding human performance. Human behavior is commonly described using linear time-invariant models, averaging-out all non-linear and time-varying effects, which are gathered into the remnant. These models are limited in their capability to capture particular tracking strategies that an experienced subject may learn to use. In this paper, we consider manual control from a different perspective, namely through investigating the probability densities of the tracking error for different regions of the target signal amplitude. Results show that distinct strategies become apparent for compensatory, pursuit and preview tracking tasks. Effects of these strategies are often averaged-out by current models and can only be captured in situation-dependent models. Modeling this systematic human adaptation not captured in linear models could potentially lead to better model fits and explain/reduce part of the remnant.","Cybernetics; manual control; probability theory; system identification","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:39cfbff2-b88e-40d9-9c52-f1de9038c3f3","http://resolver.tudelft.nl/uuid:39cfbff2-b88e-40d9-9c52-f1de9038c3f3","A Call for Scaling Literacy: On strategic dimensions and directions of systemic scaling","Mulder, I. (TU Delft Design Conceptualization and Communication); Buckenmayer, M.B. (Student TU Delft); Murphy, Ryan J.A. (Memorial University of Newfoundland)","","2022","Scaling is a motif describing the proportionate growth of innovation. Over the past decade, scholars have adapted the original idea of scaling from business to differentiate different ways to scale that are more appropriate in the context of social innovation. Scaling is sometimes thought of as a panacea: it is the end result, purpose, or answer to what we are trying to achieve. However, scaling remains ill-defined in systems change: we do not have a commonly agreed-upon
language for what we are scaling, where we are scaling, or how we are scaling change in social systems. Instead, systemic designers refer to a mix of jargon from (social) innovation, design, systemic change, and/or transition design.
Although these fields share similar ambitions for scaling, we argue that systemic designers need advanced scaling strategies for systemic innovation. The complexity of issues addressed by systemic design requires a better understanding of how scaling systems change happens and demands building capabilities for designing for these different dimensions and directions of scale. The context of the study is a Master-level course building the capacity designers need to understand when maturing systemic social innovations. Students demonstrated a richness in their scaling strategies distinguishing different dimensions and layers of scale. The current work unfolds dimensions of scaling and scaling strategies necessary for systemic scaling and elaborates upon a 2 multi-level framework for scaling literacy. We conclude with a call for scaling literacy to further advance systemic design’s methodological practices and expand the capabilities and action repertoire of future generations of systemic designers.","design capabilities; design curricula; scaling literacy; scaling strategies; social innovation; systems change; systemic impact","en","conference paper","Systemic Design Association","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:e9b6644b-d038-40cc-8eb1-ebb0c5eda606","http://resolver.tudelft.nl/uuid:e9b6644b-d038-40cc-8eb1-ebb0c5eda606","Scaling Circular Collaborations in Cities through engagement","Odayakulam Balasubramaniam, D. (Student TU Delft); Brown, P.D. (TU Delft Design for Sustainability); Calderon Gonzalez, A. (TU Delft Design Conceptualization and Communication); Mulder, I. (TU Delft Design Conceptualization and Communication)","Fitzpatrick, C. (editor)","2022","Circular economy has gained traction within companies resulting in many exploring new product and business model combinations. Yet, to transition towards a circular economy on a societal level requires going beyond new product and market-based opportunities. To enable societal level change, ecosystem-level innovations are important and so collaboration plays a key role. Cities are considered in this paper as hubs of innovation playing a key role in transitioning to a circular economy. They are responsible for 80% of global resource consumption, with a high concentration of capital, data and talent spread over a relatively small geographic area; making them an important part of societal level transitions. The current work stresses the need to understand and support collaborations in transitioning towards a circular economy. This paper explores what factors influence collaborations and how organizations collaborate for a circular economy in the context of cities. An initial literature review resulted in a framework for exploration, which informed the set-up of the questionnaire. This helped in conducting semi-structured interviews with people ranging from founders, designers to engineers from six circular start-ups, which operate and utilize the resources in cities; to understand how different organisations collaborate in cities. Results showed they focus on operationalizing their innovation through engagement with various stakeholders. As they increased their visibility in cities showcasing their value, increasing the ways and number of engagements, the organisation engaged with people and organisations having similar values and grew by scaling through engagement. This paper elaborates the idea of scaling through engagement as a way for circular organisations to scale.","Circular Economy; Cities; Collaboration; Engagement; Scaling Innovation","en","conference paper","University of Limerick","","","","","","","","","","Design for Sustainability","","",""
"uuid:fd570765-74c1-4a74-b5df-97c401a06419","http://resolver.tudelft.nl/uuid:fd570765-74c1-4a74-b5df-97c401a06419","A study on strategic activities to foster design practices in a local government organization","Kim, A. (TU Delft Methodologie en Organisatie van Design); van der Bijl-Brouwer, M. (TU Delft Methodologie en Organisatie van Design); Mulder, I. (TU Delft Design Conceptualization and Communication); Lloyd, P.A. (TU Delft Methodologie en Organisatie van Design)","","2022","In recent years, governments have increasingly pursued innovation by embed-ding design into their organizations. One particularly common approach to em-bedding design in government organization is to establish public sector innova-tion labs. These labs are described as contributors and facilitators of innovation in policymaking processes; however, less light has been shed on the role of in-house designers (including these labs) in fostering and managing the changes made by design practices within government organizations. In the current study, design management has been used as a theoretical lens to study the strategic activities of in-house designers in a Dutch municipality to embed design within the organization. The findings show the importance of strategic activity by in-house designers to foster design practice and resulting organizational changes and the need for participation of more organizational members in this activity. We conclude with setting an agenda for more research and practices on strategic activities to foster design practices and organizational changes in government.","design for policy; embedding design; design management; Local government","en","conference paper","","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:1c98ec76-fb6f-46e5-bc9e-a2f9d1052c37","http://resolver.tudelft.nl/uuid:1c98ec76-fb6f-46e5-bc9e-a2f9d1052c37","Evaluation of a Decision-Based Invocation Strategy for Adaptive Support for Air Traffic Control","IJtsma, Martijn (Ohio State University); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2022","Air traffic controller workload is a limiting factor in the current air traffic management system. Adaptive support systems have the potential to balance controller workload and gain acceptance as they provide support during times of need. Challenges in the design of adaptive support systems are to decide when and how to trigger support. The goal of this study is to gain empirical insights into these challenges through a human-in-the-loop experiment, featuring a simplified air traffic control environment in which a novel triggering mechanism uses the quality of the controller's decisions to determine when support is needed. The designed system seeks to prevent high workload conditions by providing resolution advisories when the controller exceeds a threshold of 'self-complicating' decisions. Results indicate that the new system is indeed capable of increasing the efficiency and safety compared to full manual control without intervention. More adaptive support, however, increased the frustration of participants, decreased acceptance, and did not result in improved workload ratings. These findings suggest that, unless we can better infer human intent in complex work environments, adaptive support at the level of decision-making is problematic. A potentially more fruitful direction is to provide support at the level of information integration, with full decision-making authority with the human.","Adaptive intervention system; Adaptive systems; Aerospace control; air traffic control (ATC); Aircraft; Automation; Control systems; decision quality; Monitoring; Task analysis; triggering threshold","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Control & Simulation","","",""
"uuid:94502915-707d-487a-95c0-ae8fa0122694","http://resolver.tudelft.nl/uuid:94502915-707d-487a-95c0-ae8fa0122694","Limits of Defect Tolerance in Perovskite Nanocrystals: Effect of Local Electrostatic Potential on Trap States","du Fossé, I. (TU Delft ChemE/Opto-electronic Materials); Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Almeida, Guilherme (Student TU Delft); Spruit, Anne G.M. (Student TU Delft); Infante, Ivan (Istituto Italiano di Tecnologia); Grozema, F.C. (TU Delft ChemE/Opto-electronic Materials); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials)","","2022","One of the most promising properties of lead halide perovskite nanocrystals (NCs) is their defect tolerance. It is often argued that, due to the electronic structure of the conduction and valence bands, undercoordinated ions can only form localized levels inside or close to the band edges (i.e., shallow traps). However, multiple studies have shown that dangling bonds on surface Br- can still create deep trap states. Here, we argue that the traditional picture of defect tolerance is incomplete and that deep Br- traps can be explained by considering the local environment of the trap states. Using density functional theory calculations, we show that surface Br- sites experience a destabilizing local electrostatic potential that pushes their dangling orbitals into the bandgap. These deep trap states can be electrostatically passivated through the addition of ions that stabilize the dangling orbitals via ionic interactions without covalently binding to the NC surface. These results shed light on the formation of deep traps in perovskite NCs and provide strategies to remove them from the bandgap.","","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:169e191d-983e-4f8c-8ab7-955c9670cc40","http://resolver.tudelft.nl/uuid:169e191d-983e-4f8c-8ab7-955c9670cc40","Estimating Single-Epoch Integrated Atmospheric Refractivity from InSAR for Assimilation in Numerical Weather Models","Mulder, G. (TU Delft Mathematical Geodesy and Positioning; Royal Netherlands Meteorological Institute (KNMI)); van Leijen, F.J. (TU Delft Mathematical Geodesy and Positioning); Barkmeijer, Jan (Royal Netherlands Meteorological Institute (KNMI)); De Haan, Siebren (Royal Netherlands Meteorological Institute (KNMI)); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning)","","2022","Numerical weather prediction (NWP) models are used to predict the weather based on current observations in combination with physical and mathematical models. Yet, they are limited by the spatial density and the accuracy of the available observations. Satellite radar interferometry (InSAR) is known to be extremely sensitive to the 3D atmospheric refractivity distribution, and has a high spatial resolution, providing information that can be used for assimilation in NWP models. However, due to the inherent superposition of two or more atmospheric states, only biased and temporally differenced signals can be retrieved, that can also be contaminated by deformation signals and decorrelation. Here we present a method to estimate single-epoch absolute atmospheric delays by combining InSAR time series with prior NWP model prediction time series, using a constrained least-squares estimation. We show that this leads to a solution that reliably extracts the single-epoch relative delays from InSAR data and uses prior NWP model data to find the absolute reference for these delays, while mitigating long-term deformation and decorrelation signal. This approach leads to repetitive delay updates with a spatial resolution of 500 m, that can be directly assimilated into numerical weather models.","atmospheric delay; Atmospheric modeling; Data models; Delays; Meteorology; nSAR; Numerical models; NWP model; Predictive models; single epoch; Strain","en","journal article","","","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:cb2069ee-f143-419e-8b04-7e4d580d87fa","http://resolver.tudelft.nl/uuid:cb2069ee-f143-419e-8b04-7e4d580d87fa","Comprehensive characterization of pre- and post-treatment samples of breast cancer reveal potential mechanisms of chemotherapy resistance","Hoogstraat, Marlous (Netherlands Cancer Institute); Lips, Esther H. (Netherlands Cancer Institute); Mayayo-Peralta, Isabel (Netherlands Cancer Institute); Mulder, Lennart (Netherlands Cancer Institute); Kristel, Petra (Netherlands Cancer Institute); van der Heijden, Ingrid (Netherlands Cancer Institute); Annunziato, Stefano (Netherlands Cancer Institute); van Seijen, Maartje (Netherlands Cancer Institute); Wessels, L.F.A. (TU Delft Pattern Recognition and Bioinformatics; Netherlands Cancer Institute)","","2022","When locally advanced breast cancer is treated with neoadjuvant chemotherapy, the recurrence risk is significantly higher if no complete pathologic response is achieved. Identification of the underlying resistance mechanisms is essential to select treatments with maximal efficacy and minimal toxicity. Here we employed gene expression profiles derived from 317 HER2-negative treatment-naïve breast cancer biopsies of patients who underwent neoadjuvant chemotherapy, deep whole exome, and RNA-sequencing profiles of 22 matched pre- and post-treatment tumors, and treatment outcome data to identify biomarkers of response and resistance mechanisms. Molecular profiling of treatment-naïve breast cancer samples revealed that expression levels of proliferation, immune response, and extracellular matrix (ECM) organization combined predict response to chemotherapy. Triple negative patients with high proliferation, high immune response and low ECM expression had a significantly better treatment response and survival benefit (HR 0.29, 95% CI 0.10–0.85; p = 0.02), while in ER+ patients the opposite was seen (HR 4.73, 95% CI 1.51–14.8; p = 0.008). The characterization of paired pre-and post-treatment samples revealed that aberrations of known cancer genes were either only present in the pre-treatment sample (CDKN1B) or in the post-treatment sample (TP53, APC, CTNNB1). Proliferation-associated genes were frequently down-regulated in post-treatment ER+ tumors, but not in triple negative tumors. Genes involved in ECM were upregulated in the majority of post-chemotherapy samples. Genomic and transcriptomic differences between pre- and post-chemotherapy samples are common and may reveal potential mechanisms of therapy resistance. Our results show a wide range of distinct, but related mechanisms, with a prominent role for proliferation- and ECM-related genes.","","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:498dafe0-7241-4e1a-aeb1-d01c6a34d273","http://resolver.tudelft.nl/uuid:498dafe0-7241-4e1a-aeb1-d01c6a34d273","Motorcycle simulator subjective and objective validation for low speed maneuvering","Grottoli, M. (TU Delft Intelligent Vehicles; Siemens PLM Software); Mulder, Max (TU Delft Control & Simulation); Happee, R. (TU Delft Intelligent Vehicles)","","2022","The use of driving simulators for training and for development of new vehicles is widely spread in the automotive industry. In the last decade, a few motorcycle riding simulators have been developed for similar purposes, with focus on maneuvering at high speed. This article presents the subjective and objective evaluation of a motorcycle riding simulator specifically for low speed longitudinal and lateral maneuvering, between 0 and 10 ms–1. An experiment was conducted with and without platform motion, focusing on three maneuvers: acceleration from standstill, braking to standstill and turning at constant speed. Participants briefly evaluated the fidelity of the simulator after each maneuver and more extensively after each motion condition. Behavioral fidelity was evaluated using experimental data measured on an instrumented motorcycle. Overall, the results show that the participants could reproduce the selected maneuvers without falling or losing balance, reporting a sufficient level of simulator realism. In terms of subjective fidelity, platform motion had a positive effect on simulator presence, significantly increasing the feeling of being involved in the virtual environ0ment. In terms of behavioral fidelity, the comparison between the simulator and experimental results shows good agreement, with a limited positive influence of motion for the braking maneuver, which indicates that for this maneuver the use of motion is beneficial to reproduce the real-life experience and performance.","Motorcycle; simulator; validation","en","journal article","","","","","","","","","","","Intelligent Vehicles","","",""
"uuid:b3b9d0de-2910-4569-91a4-29b6aa46113f","http://resolver.tudelft.nl/uuid:b3b9d0de-2910-4569-91a4-29b6aa46113f","Scaling Local Bottom-Up Innovations through Value Co-Creation","Marradi, C. (TU Delft Education AE); Mulder, I. (TU Delft Design Conceptualization and Communication)","","2022","Bottom-up initiatives of active citizens are increasingly demonstrating sustainable practices within local ecosystems. Local urban farming, sustainable agri-food systems, circular supply chains, and community fablabs are exemplary ways of tackling global challenges on a local level. Although promising in accelerating towards future-proof systems, these hyper-localized, bottom-up initiatives often struggle to take root in new contexts due to embedded socio-cultural challenges. With the premise that transformative capacity can be co-created to overcome such scaling challenges, the current work addresses the identified gap in scaling bottom-up initiatives into locally embedded ecosystems. While how to diffuse such practices across contexts is not straightforward, we introduce a three-phased approach enabling knowledge exchange and easing collaboration across cultures and ecosystems. The results allowed us to define common scalability criteria and to unfold scaling as a multi-step learning process to bridge identified cognitive and context gaps. The current article contributes to a broader activation of impact-driven scaling strategies and value creation processes that are transferable across contexts and deemed relevant for local ecosystems that are willing to co-create resilient socio-economic systems.","co-creation; cross-cultural learning; innovation ecosystems; mission-driven innovation; resilience; scaling strategies; urban food systems; value creation process","en","journal article","","","","","","","","","","","Education AE","","",""
"uuid:929b2360-2d3a-4acb-8f68-ac736c50a400","http://resolver.tudelft.nl/uuid:929b2360-2d3a-4acb-8f68-ac736c50a400","Spectropolarimetry of life: Airborne measurements from a hot air balloon","Mulder, W. (TU Delft Astrodynamics & Space Missions; Universiteit Leiden); Patty, C. H.Lucas (University of Bern); Spadaccia, Stefano (University of Bern); Pommerol, Antoine (University of Bern); Demory, Brice Olivier (University of Bern); Keller, Christoph U. (Universiteit Leiden; Lowell Observatory); Kühn, Jonas G. (University of Bern; Université de Genève); Snik, Frans (Universiteit Leiden); Stam, D.M. (TU Delft Astrodynamics & Space Missions)","Lakshminarayanan, Vasudevan (editor); Creath, Katherine (editor); Shaw, Joseph A. (editor)","2022","Does life exist outside our Solar System A first step towards searching for life outside our Solar System is detecting life on Earth by using remote sensing applications. One powerful and unambiguous biosignature is the circular polarization resulting from the homochirality of biotic molecules and systems. We aim to investigate the possibility of identifying and characterizing life on Earth by using airborne spectropolarimetric observations from a hot air balloon during our field campaign in Switzerland, May 2022. In this proceeding we present the optical-setup and the data obtained from aerial circular spectropolarimetric measurements of farmland, forests, lakes and urban sites. We make use of the well-calibrated FlyPol instrument that measures the fractionally induced circular polarization (V/I) of (reflected) light with a sensitivity of < 10-4. The instrument operates in the visible spectrum, ranging from 400 to 900 nm. We demonstrate the possibility to distinguish biotic from abiotic features using circular polarization spectra and additional broadband linear polarization information. We review the performance of our optical-setup and discuss potential improvements. This sets the requirements on how to perform future airborne spectropolarimetric measurements of the Earth's surface features from several elevations.","Biosignatures; Earth observation; Field campaign; Polarization; Remote-sensing; Spectropolarimetry","en","conference paper","SPIE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Astrodynamics & Space Missions","","",""
"uuid:5243a2d4-b23f-41fa-97b6-cc469c3de809","http://resolver.tudelft.nl/uuid:5243a2d4-b23f-41fa-97b6-cc469c3de809","In Situ Study of Hydrogen Permeable Electrodes for Electrolytic Ammonia Synthesis Using Near Ambient Pressure XPS","Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Izelaar, B. (TU Delft Large Scale Energy Storage); van Noordenne, D.D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Jungbacker, M.P. (TU Delft ChemE/Materials for Energy Conversion and Storage); Kolen, M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Karanth, P. (TU Delft ChemE/Materials for Energy Conversion and Storage); Cruz, Daniel (Fritz-Haber-Institut der Max-Planck-Gesellschaft); Zeller, Patrick (Fritz-Haber-Institut der Max-Planck-Gesellschaft; Helmholtz-Zentrum Berlin für Materialen und Energie GmbH); Pérez-Dieste, Virginia (ALBA Synchrotron Light Facility); Villar-Garcia, Ignacio J. (ALBA Synchrotron Light Facility); Smith, W.A. (TU Delft ChemE/Materials for Energy Conversion and Storage; University of Colorado); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2022","Hydrogen permeable electrodes can be utilized for electrolytic ammonia synthesis from dinitrogen, water, and renewable electricity under ambient conditions, providing a promising route toward sustainable ammonia. The understanding of the interactions of adsorbing N and permeating H at the catalytic interface is a critical step toward the optimization of this NH3 synthesis process. In this study, we conducted a unique in situ near ambient pressure X-ray photoelectron spectroscopy experiment to investigate the solid-gas interface of a Ni hydrogen permeable electrode under conditions relevant for ammonia synthesis. Here, we show that the formation of a Ni oxide surface layer blocks the chemisorption of gaseous dinitrogen. However, the Ni 2p and O 1s XPS spectra reveal that electrochemically driven permeating atomic hydrogen effectively reduces the Ni surface at ambient temperature, while H2 does not. Nitrogen gas chemisorbs on the generated metallic sites, followed by hydrogenation via permeating H, as adsorbed N and NH3 are found on the Ni surface. Our findings suggest that the first hydrogenation step to NH and the NH3 desorption might be limiting under the operating conditions. The study was then extended to Fe and Ru surfaces. The formation of surface oxide and nitride species on iron blocks the H permeation and prevents the reaction to advance; while on ruthenium, the stronger Ru-N bond might favor the recombination of permeating hydrogen to H2 over the hydrogenation of adsorbed nitrogen. This work provides insightful results to aid the rational design of efficient electrolytic NH3 synthesis processes based on but not limited to hydrogen permeable electrodes.","adsorption; ammonia synthesis; hydrogen permeation; in situ; NAP-XPS; nitrogen","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:2e24a763-1885-46c9-a96e-0faf9a4867a9","http://resolver.tudelft.nl/uuid:2e24a763-1885-46c9-a96e-0faf9a4867a9","Elucidation of Enhanced Lithium Conductivity in Nanoporous Ionogel Using Solid State NMR","Weijers, M.J. (TU Delft ChemE/Materials for Energy Conversion and Storage); Karanth, P. (TU Delft ChemE/Materials for Energy Conversion and Storage); Ganapathy, S. (TU Delft RID/TS/Instrumenten groep); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2022","Nanostructured solid composite electrolyte or nano-SCE, which is composed of an ionic liquid, nanoporous silica, and residuals of immobilized precursor components, shows promising synergistic properties. The ionic conductivity of nano-SCE is in the range of 2–5 mS cm−1, which exceeds the bulk ionic liquid conductivity at ambient temperature, while maintaining characteristics of a solid electrolyte such as having no leakage issues as the ionic liquid is confined, and lower flammability compared to conventional liquid electrolytes. In this study, the underlying mechanism of enhanced conductivity is investigated by using magic angle spinning NMR and NMR relaxometry analysis. Water, one of the volatile precursor molecules has shown to play a key role in the final conductivity and stability at the solid-electrolyte interface, as it enhances the temperature range in which the ionic liquid remains mobile. In line with previous studies, water with lowered mobility is found in the silicon matrix. The activation energies of lithium ion transfer probed by NMR relaxometry, however, do not change as function of water content. The increase in bulk mobility of lithium ions under ambient conditions compared to water-less nano-SCE is found to be the origin of the altered conductivity of this material.","diffusivity; ionic conductivity; ionogel; nanoporous silica; nuclear magnetic resonance spectroscopy","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:499f0f6d-444e-456c-8e1c-8f571f3037e3","http://resolver.tudelft.nl/uuid:499f0f6d-444e-456c-8e1c-8f571f3037e3","Measurement of single nanoparticle anisotropy by laser induced optical alignment and Rayleigh scattering for determining particle morphology","Rademacher, Markus (University College London (UCL)); Gosling, Jonathan (University College London (UCL)); Pontin, Antonio (University College London (UCL)); Toroš, Marko (University of Glasgow); Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials); Barker, P. F. (University College London (UCL))","","2022","We demonstrate the measurement of nanoparticle anisotropy by angularly resolved Rayleigh scattering of single optical levitated particles that are oriented in space via the trapping light in vacuum. This technique is applied to a range of particle geometries from perfect spherical nanodroplets to octahedral nanocrystals. We show that this method can resolve shape differences down to a few nanometers and be applied in both low-damping environments, as demonstrated here, and in traditional overdamped fluids used in optical tweezers.","","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:2227c0ee-77eb-424f-866d-b94adc5ca963","http://resolver.tudelft.nl/uuid:2227c0ee-77eb-424f-866d-b94adc5ca963","Long-Range Charge Transport via Redox Ligands in Quantum Dot Assemblies","Vogel, Y.B. (TU Delft ChemE/Opto-electronic Materials); Stam, M. (TU Delft ChemE/Opto-electronic Materials); Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials)","","2022","We present a strategy to actively engineer long-range charge transport in colloidal quantum dot assemblies by using ligand functionalities that introduce electronic states and provide a path for carrier transfer. This is a shift away from the use of inactive spacers to modulate charge transport through the lowering of the tunneling barrier for interparticle carrier transfer. This is accomplished with the use of electronically coupled redox ligands by which a self-exchange chain reaction takes place and long-range charge transport is enabled across the film. We identified the different modes of charge transport in these quantum dot/redox ligand assemblies, their energetic position and kinetics, and explain how to rationally manipulate them through modulation of the Fermi level and redox ligand coverage.","charge transfer; charge transport; electrochemistry; quantum dots; redox ligands","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:7111fd52-526c-4e01-bb3d-8f27eae7c1f4","http://resolver.tudelft.nl/uuid:7111fd52-526c-4e01-bb3d-8f27eae7c1f4","Combinatorial Screening of Bimetallic Electrocatalysts for Nitrogen Reduction to Ammonia Using a High-Throughput Gas Diffusion Electrode Cell Design","Kolen, M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Antoniadis, Grigorios (Student TU Delft); Schreuders, H. (TU Delft ChemE/O&O groep); Boshuizen, B. (TU Delft ChemE/O&O groep); van Noordenne, D.D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Smith, W.A. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2022","The electrochemical nitrogen reduction reaction (NRR) is a promising alternative to the current greenhouse gas emission intensive process to produce ammonia (NH3) from nitrogen (N2). However, finding an electrocatalyst that promotes NRR over the competing hydrogen evolution reaction (HER) has proven to be difficult. This difficulty could potentially be addressed by accelerating the electrocatalyst development for NRR by orders of magnitude using high-throughput (HTP) workflows. In this work, we developed a HTP gas diffusion electrode (GDE) cell to screen up to 16 electrocatalysts in parallel. The key innovation of the cell is the use of expanded Polytetrafluoroethylene (ePTFE) gas diffusion layers (GDL) which simplifies the handling of catalyst arrays compared to carbon fabrics and enables sufficient N2 mass transport. We demonstrate the robustness of the HTP workflow by screening 528 bimetallic catalysts of composition AB (A,B = Ag, Al, Au, Co, Cu, Fe, Mn, Mo, Ni, Pd, Re, Ru, W) for NRR activity. None of the materials produced ammonia significantly over background level which emphasizes the difficulty of finding active electrocatalysts for NRR and narrows down the search space for future studies.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:67e1df92-d38e-4627-a2f5-187cbb50c0b7","http://resolver.tudelft.nl/uuid:67e1df92-d38e-4627-a2f5-187cbb50c0b7","More Continuous Mass-Lumped Triangular Finite Elements","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2022","When solving the wave equation with finite elements, mass lumping allows for explicit time stepping, avoiding the cost of a lower-upper decomposition of the large sparse mass matrix. Mass lumping on the reference element amounts to numerical quadrature. The weights should be positive for stable time stepping and preserve numerical accuracy. The standard triangular polynomial elements, except for the linear element, do not have these properties. Accuracy can be preserved by augmenting them with higher-degree polynomials in the interior. This leaves the search for elements with positive weights, which were found up to degree 9 by various authors. The classic accuracy condition, however, is too restrictive. A sharper, less restrictive condition recently led to new mass-lumped tetrahedral elements up to degree 4. Compared to the known ones up to degree 3, they have less nodes and are computationally more efficient. The same criterion is applied here to the construction of triangular elements. For degrees 2 to 4, these turn out to be identical to the known ones. For degree 5, the number of nodes is the same as for the known element, but now there are infinitely many solutions. Some of these have a considerably larger stability limit for time stepping. For degree 6, two elements are found with less nodes than the known ones. For degree 7, one element with less nodes was found but with a negative weight, making it useless for time stepping with the wave equation. If the number of nodes is the same as for the classic element, there are now infinitely many solutions. Numerical tests for a homogeneous wave-propagation problem with a point source confirm the expected accuracy of the new elements. Some of them require less compute time than those obtained with the more restrictive accuracy criterion.","Finite elements; Numerical quadrature; Triangles; Wave equation","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:cb4731d6-0e89-49f5-b3f1-2c9e769c4a89","http://resolver.tudelft.nl/uuid:cb4731d6-0e89-49f5-b3f1-2c9e769c4a89","Human-automation interaction for helicopter flight: Comparing two decision-support systems for navigation tasks","Friesen, D. (TU Delft Control & Simulation; Politecnico di Milano); Borst, C. (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); Masarati, Pierangelo (Politecnico di Milano); Mulder, Max (TU Delft Control & Simulation)","","2022","This paper investigates the effects of different automation design philosophies for a helicopter navigation task. A baseline navigation display is compared with two more advanced systems: an advisory display, which provides a discrete trajectory suggestion; and a constraint-based display, which provides information about the set of possible trajectory solutions. The results of a human-in-the-loop experiment with eight pilot participants show a significant negative impact of the advisory display on pilot trajectory decision-making: out of the 16 encountered off-nominal situations across the experiment, only 6 were solved optimally. The baseline and constraint-based display both lead to better decisions, with 14 out of 16 being optimal. However, pilots still preferred the advisory display, in particular in off-nominal situations. These results highlight that even when a support system is preferred by pilots, it can have strong inadvertent negative effects on their decision-making.","Automation; Display; Helicopter; Human-machine interface","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:f695d155-a1ee-4a54-b5d2-39e2e5801624","http://resolver.tudelft.nl/uuid:f695d155-a1ee-4a54-b5d2-39e2e5801624","A collaborative learning infrastructure to build capacity for urban transformations","Mulder, I. (TU Delft Design Conceptualization and Communication); Magni, A. (TU Delft Design Conceptualization and Communication)","","2022","An increasing number of social innovators are leveraging cities as urban learning ecosystems in order to experiment with design approaches to tackle societal challenges at a local level. However, the scale and complexity of these challenges force them to constantly acquire new capabilities to advance the local experimentation towards systemic change. We introduce co-design as a transformative community-driven design method to facilitate innovators to continuously identify, connect, co-define, and share with other peers their learning journeys to build capacity over time for addressing societal challenges. The current article elaborates upon a capacity-building framework that not only resulted in elaborate training activities for urban transformations, but also fostered a community of practice that was instrumental to self-sustain a learning network. Results highlight the importance of developing a collaborative learning infrastructure capable of expanding the pool of societal actors contributing to the further diffusion and co-creation of knowledge for urban transformations","Capacity building; Co-design; Collaborative learning; Learning ecosystem; Reflection; Self-development; Urban innovators; Urban transformations.","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:c57471a6-6eb3-4fdf-987e-2737819376fa","http://resolver.tudelft.nl/uuid:c57471a6-6eb3-4fdf-987e-2737819376fa","Collaborative Sensemaking of Design-Enabled Urban Innovations:: The MappingDESIGNSCAPES Case","de Moor, Aldo (CommunitySense, Tilburg); Papalioura, Evi (Ministry of Environment and Energy, Thessaloniki); Taka, Evi (Municipality of Neapolis-Sikeon, Thessaloniki); Rapti, Dora (External organisation); Wolff, Annika (LUT University); Knutas, Antti (LUT University); te Velde, T. (Suit-Case); Mulder, I. (TU Delft Design Conceptualization and Communication)","Polovina, Rubina (editor); Polovina, Simon (editor); Kemp, Neil (editor)","2022","Wicked societal problems, such as environmental issues and climate
change, are complex, networked problems involving numerous intertwined issues,no optimal solutions, and a wide range of stakeholders. Cities are problem owners and living labs for finding solutions through design-enabled innovation initiatives. However, to reach collective impact, it is paramount that these initiatives can learn from one another and align efforts through collaborative sensemaking. In the MappingDESIGNSCAPES project, we piloted a participatory collaboration mapping approach for cross-case sensemaking across design-enabled urban innovation initiatives. We used the CommunitySensor methodology for participatory community network mapping together with the Kumu online network visualization tool to help representatives of three urban prototype cases share and collectively make sense of their design lessons learnt. In this second of two papers, we build on the participatory mapping foundation introduced in [1]. We describe the collaborative sensemaking approach used, then present the core collaboration patterns and
common perspectives that form the sensemaking scaffolding. We show how we
collaboratively made sense by first taking individual perspectives, then making
common sense together. An extended discussion puts our findings in a larger context of how an approach like MappingDESIGNSCAPES can be used to move from collaborative sensemaking to collective impact in design-driven urban innovation.","Design-enabled urban innovation; Participatory mapping; Collaborative sensemaking; Collective impact","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Design Conceptualization and Communication","","",""
"uuid:a15fd542-ef07-4b06-b9df-62dd0a1ebc96","http://resolver.tudelft.nl/uuid:a15fd542-ef07-4b06-b9df-62dd0a1ebc96","In search of Inclusive Participatory City-Making","Lopez Reyes, M.E. (Student TU Delft); Mulder, I. (TU Delft Design Conceptualization and Communication)","","2021","Participatory methods have been widely explored in the public sector to democratize city-making projects and foster civic engagement. Although well-intentioned, participatory processes still too often exclude citizens. The current study looks for elements enabling city makers to articulate an inclusive Participatory City Making process. Starting from a review of participatory methods, we distilled the conditions necessary to consider a participatory process inclusive. In order to understand inclusiveness in practice, we performed interviews with a diverse group of city makers in an ongoing local participation process. The result is a framework that offers eight moments of reflection for public sector city makers to articulate more inclusive Participatory City-Making processes.","Citizen Engagement; Reflection; Participation; Inclusiveness","en","conference paper","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:9778a674-f50e-49d3-beaf-24c0180038d3","http://resolver.tudelft.nl/uuid:9778a674-f50e-49d3-beaf-24c0180038d3","Quality comparison of motion cueing algorithms for urban driving simulations","Kolff, Maurice (BMW Group; Student TU Delft); Venrooij, J. (TU Delft Control & Simulation; BMW Group); Schwienbacher, Markus (BMW Group); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","Kemeny, Andras (editor)","2021","When designing driving simulation experiments with motion cueing, it is often necessary to make choices between Motion Cueing Algorithms (MCAs) without being fully able to know how well an MCA will perform during the experiment. Choices between MCAs can therefore be greatly supported by previous measurements or predictions of motion cueing quality. This paper describes a data collection experiment on a nine degree-of-freedom motion-base simulator, in which participants are asked to continuously rate the motion cueing quality during a pre-recorded drive through an urban environment. Three benchmark MCAs are compared: a Model-Predictive Control (MPC) algorithm with infinite prediction horizon, a Classical Washout Algorithm (CWA) tuned for the use-case, and the same algorithm (CWA), but with the tilt-coordination channels turned off. By comparing ratings for the whole scenario, as well as ratings for each maneuver individually, the results show a preference of the presence of tilt-coordination, as well as a preference for the optimization-based MPC algorithm over the CWA condition. The collected data will be used directly for modeling and predicting motion cueing quality for future experiments at BMW, such that the best-suited MCA and parameter setting can be selected before experiments.","Motion cueing; Quality comparison; Urban simulations","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:c15cbe9b-f9a9-40ae-82a2-8fe1e2480761","http://resolver.tudelft.nl/uuid:c15cbe9b-f9a9-40ae-82a2-8fe1e2480761","Quality comparison of motion cueing algorithms for urban driving simulations","Kolff, Maurice (BMW Group; Student TU Delft); Venrooij, J. (TU Delft Control & Simulation; BMW Group); Schwienbacher, Markus (BMW Group); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2021","When designing driving simulation experiments with motion cueing, it is often necessary to make choices between Motion Cueing Algorithms (MCAs) without being fully able to know how well an MCA will perform during the experiment. Choices between MCAs can therefore be greatly supported by previous measurements or predictions of motion cueing quality. This paper describes a data collection experiment on a nine degree-of-freedom motion-base simulator, in which participants are asked to continuously rate the motion cueing quality during a pre-recorded drive through an urban environment. Three benchmark MCAs are compared: a Model-Predictive Control (MPC) algorithm with infinite prediction horizon, a Classical Washout Algorithm (CWA) tuned for the use-case, and the same algorithm (CWA), but with the tilt-coordination channels turned off. By comparing ratings for the whole scenario, as well as ratings for each maneuver individually, the results show a preference of the presence of tilt-coordination, as well as a preference for the optimization-based MPC algorithm over the CWA condition. The collected data will be used directly for modeling and predicting motion cueing quality for future experiments at BMW, such that the best-suited MCA and parameter setting can be selected before experiments.","Motion cueing; Quality comparison; Urban simulations","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:32481845-9aad-4784-b0fc-92e87e5ffb61","http://resolver.tudelft.nl/uuid:32481845-9aad-4784-b0fc-92e87e5ffb61","Rotorcraft Safety: A Simulator-based Training Perspective","Scaramuzzino, Paolo Francesco (TU Delft Control & Simulation; Politecnico di Milano); Pavel, M.D. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Quaranta, Giuseppe (Politecnico di Milano); Mulder, Max (TU Delft Control & Simulation)","","2021","Training has the potential to inject a “safety vaccination” into the rotorcraft community by reducing the number of accidents. The term training should not be intended only in a strict sense, i.e., as pilot technical skills training, but more broadly as risk avoidance and safety culture training. As in the case of vaccination, where immunity is created only when applied on a large scale, helicopter accidents will not be eradicated until every player in the rotorcraft community is involved in the safety enhancement process. In particular, as outlined by accident and safety reports, a reduction in the helicopter accident rate cannot be accomplished disregarding pilots’ training and the contribution that _ight simulators can provide to both training and certi_cation. This paper provides an overview of the research into simulator training for helicopter pilots conducted as part of the European Joint Doctorate NITROS (Network for Innovative Training on Rotorcraft Safety). An approach that requires an in-depth analysis of the actual training task is adopted for two different maneuvers, namely hover and autorotation. This approach enables the training developer to understand what are the aspects of the actual training situation that should be reproduced in the simulated training situation to avoid ineffective training and negative transfer of skills. Moreover, such an approach allows to identify differences in terms of requirements between the training of basic and advanced maneuvers and between initial and recurrent training. The results of three different pilot-in-theloop experiments, performed to explicitly con_rm the effectiveness of developed training programs and to understand whether certain elements of the simulation can foster the development of superior _ying skills, are summarized in this paper.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:40d1d79d-86ef-4a7b-ab05-cae20d1a7659","http://resolver.tudelft.nl/uuid:40d1d79d-86ef-4a7b-ab05-cae20d1a7659","The Apparent Anisotropy of the SEG-EAGE Overthrust Mode","Cupillard, Paul (Lorraine University); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); Anquez, Pierre (Lorraine University); Mazuyer, Antoine (Lorraine University; Stanford University); Barthélémy, J. (Cerema: Center for Studies and Expertise on Risks, the Environment, Mobility and Planning)","","2021","The Earth interior contains heterogeneities at all scales, ranging from pores and mineral grains to major global units. On the contrary, seismic recordings only contain variations larger than the minimum wavelength λmin. The heterogeneities smaller than λmin are naturally smoothed by the wavefield, leading to effective media when inverting seismic recordings to image the Earth. In particular, oriented small-scale structures lead to apparent anisotropy. In the present work, we apply the non-periodic homogenization method to the SEG-EAGE overthrust model to get the effective properties of a typical subsurface medium and to estimate the magnitude and the symmetry of the apparent anisotropy. We show that such anisotropy can reach 18%, most of it being explained by locally-tilted transverse isotropy. We also show that using the effective properties within an anisotropic wave simulator considerably decreases the computation requirement with respect to a wave simulation in the original model.","","en","conference paper","EAGE","","","","","Accepted Author Manuscript","","2021-06-11","","","Applied Geophysics and Petrophysics","","",""
"uuid:ec2a912a-c1e0-430e-8365-d9ae3c6623fd","http://resolver.tudelft.nl/uuid:ec2a912a-c1e0-430e-8365-d9ae3c6623fd","On the error behaviour of force andmoment sources in tetrahedral spectral finite elements","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2021","The representation of a force or of a moment point source in a spectral finite-element code for modelling elastic wave propagation becomes fundamentally different in degenerate cases where the source is located on the boundary of an element. This difference is related to the fact that the finite-element basis functions are continuous across element boundaries, but their derivatives are not. A method is presented that effectively deals with this problem. Tests on 1-D elements show that the numerical errors for a force source follow the expected convergence rate in terms of the element size, apart from isolated cases where superconvergence occurs. For a moment source, the method also converges but one order of accuracy is lost, probably because of the reduced regularity of the problem. Numerical tests in 3D on continuous mass-lumped tetrahedral elements show a similar error behaviour as in the 1-D case, although in 3D, the loss of accuracy for the moment source is not a severe as a full order.","","en","conference paper","EAGE","","","","","Accepted Author Manuscript","","2021-06-11","","","Applied Geophysics and Petrophysics","","",""
"uuid:24959b0b-6eb2-4082-8aae-c5047e881767","http://resolver.tudelft.nl/uuid:24959b0b-6eb2-4082-8aae-c5047e881767","A matrix-free reformulation of the multi-parameter descent and conjugate-gradient method for isotropic elastic iterative reverse-time migration","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2021","Multi-parameter inversion of linear systems appears in many problems. The focus here is on isotropic elastic iterative reverse-time migration for three position-dependent subsurface model parameters, which amounts to data fitting of processed seismic data with synthetics from the Born approximation of the elastic wave equation. In that case, the matrix of the linear system is the hessian. As it is impractical to form, a matrix-free formulation is needed, which is readily derived for the gradient descent method. For single-parameter inversion, the conjugate-gradient (CG) method is generally more efficient than simple descent. However, the multiple-parameter CG method has a significantly higher cost than the descent method. Here, first a matrix-free data-domain reformulation is derived. Then, its performance is compared to the simple descent method to see of its faster convergence justifies the higher cost. A comparison on a marine 2-D toy problem with a salt body and sea-bottom receivers shows that the multiple-parameter descent method wins in terms of efficiency if the number of iterations is limited and that the single-parameter CG method is even faster.","","en","conference paper","EAGE","","","","","Accepted Author Manuscript","","2022-04-18","","","Applied Geophysics and Petrophysics","","",""
"uuid:15d6a8ba-3bed-4ff7-8fca-4f0716a6d8b6","http://resolver.tudelft.nl/uuid:15d6a8ba-3bed-4ff7-8fca-4f0716a6d8b6","Working around the corner problem in numerically exact non-reflecting boundary conditions for the wave equation","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2021","Recently introduced non-reflecting boundary conditions are numerically exact: the solution on a given domain is the same as a subset of one on an enlarged domain where boundary reflections do not have time to reach the original domain. In 1D with second- or higher-order finite differences, a recurrence relation based on translation invariance provides the boundary conditions. In 2D or 3D, a recurrence relation was only found for a non-reflecting boundary on one or two opposing sides of the domain and zero Dirichlet or Neumann boundaries elsewhere. Otherwise, corners cause translation invariance to be lost.
The proposed workaround restores translation invariance with classic, approximately non-reflecting boundary conditions on the other sides. As a proof of principle, the method is applied to the 2-D constant-density acoustic wave equation, discretized on a rectangular domain with a second-order finite-difference scheme, first-order Enquist-Majda boundary conditions as approximate ones, and numerically exact boundary conditions in the horizontal direction. The method is computationally costly but has the advantage that it can be reused on a sequence of problems as long as the time step and the sound speed values next to the boundary are kept fixed.","","en","conference paper","EAGE","","","","","Accepted Author Manuscript","","2022-04-18","","","Applied Geophysics and Petrophysics","","",""
"uuid:694840bd-1ba1-4745-91d0-283acdd19c6f","http://resolver.tudelft.nl/uuid:694840bd-1ba1-4745-91d0-283acdd19c6f","Between-simulator comparison of motion-filter order and break frequency effects on manual control","Pool, D.M. (TU Delft Control & Simulation); Zaal, P.M.T. (Metis Technology Solutions); Pieters, M.A. (San José State University); Stroosma, O. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2021","This paper investigates the interaction effects of motion filter order and break frequency on pilots’ manual control behavior and control performance using two simulators. Eighteen pilots performed the experiment in the Vertical Motion Simulator (VMS) at NASA Ames Research Center and 20 pilots in the SIMONA Research Simulator at Delft University of Technology. The experiment used a full-factorial design with three motion filter orders (first-, second-, and third-order) and two filter break frequencies (0.5 and 2.0 rad/s), in addition to reference no-motion and full-motion conditions. Key task variables, such as the quality of the motion and visual cues and the characteristics of the sidestick, were matched across both simulators. Overall, the expected effects of filter order and break frequency variations were found, with both increasing order and increasing break frequency causing pilots to use less motion feedback in their control strategy, resulting in lower tracking performance. Furthermore, across the wide range of filter orders tested in the experiment, the existing Sinacori–Schroeder motion fidelity criterion was found to be a good predictor of the interaction effects of both filter settings on pilot control behavior. For the same motion condition, there was a consistent offset in the results between simulators, due to the more high-gain control strategy adopted by a number of the VMS pilots. Still, the observed relative trends in pilot control behavior and performance between motion conditions were equivalent in both simulators and thus accurately replicated.","","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:381f98f7-faf6-4788-a958-91627b91af8f","http://resolver.tudelft.nl/uuid:381f98f7-faf6-4788-a958-91627b91af8f","Fast Fourier transform of electromagnetic data for computationally expensive kernels","Werthmüller, D. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2021","3-D controlled-source electromagnetic data are often computed directly in the domain of interest, either in the frequency domain or in the time domain. Computing it in one domain and transforming it via a Fourier transform to the other domain is a viable alternative. It requires the evaluation of many responses in the computational domain if standard Fourier transforms are used. This can make it prohibitively expensive if the kernel is time-consuming as is the case in 3-D electromagnetic modelling. The speed of modelling obtained through such a transform is defined by three key points: solver, method and implementation of the Fourier transform, and gridding. The faster the solver, the faster modelling will be. It is important that the solver is robust over a wide range of values (frequencies or times). The method should require as few kernel evaluations as possible while remaining robust. As the frequency and time ranges span many orders of magnitude, the required values are ideally equally spaced on a logarithmic scale. The proposed fast method uses either the digital linear filter method or the logarithmic fast Fourier transform together with a careful selection of evaluation points and interpolation. In frequency-to-time domain tests this methodology requires typically 15-20 frequencies to cover a wide range of offsets. The gridding should be frequency-or time-dependent, which is accomplished by making it a function of skin depth. Optimizing for the least number of required cells should be combined with optimizing for computational speed. Looking carefully at these points resulted in much smaller computation times with speedup factors of ten or more over previous methods. A computation in one domain followed by transformation can therefore be an alternative to computation in the other domain domain if the required evaluation points and the corresponding grids are carefully chosen.","Controlled source electromagnetics (CSEM); Fourier analysis; Numerical modelling","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:64990ffe-e49d-4b27-98fd-1186cc2894a1","http://resolver.tudelft.nl/uuid:64990ffe-e49d-4b27-98fd-1186cc2894a1","Fruitful friction as a strategy to scale social innovations: A conceptual framework to enable the emergence of common ground in multi-stakeholder social innovation projects","Buckenmayer, M.B. (Student TU Delft); Gonçalves, M. (TU Delft Methodologie en Organisatie van Design); Mulder, I. (TU Delft Design Conceptualization and Communication)","","2021","Social innovations are promising to tackle today's complex global challenges, especially when they scale, leading to a higher impact, which can generate asocietal transformation. The current work elaborates on scaling deep, a specific scaling strategy aiming to shift cultural values, mindsets and beliefs. However, applying this strategy in practice is not straightforward. Therefore, we first aim to
develop an actionable strategy that supports social innovators in their scaling efforts. Our research findings show that scaling deep can be defined as an (1) internal transformation process, (2) a social process, with (3) friction being an enabler for change. Second, these insights inform a framework that makes scaling deep more actionable and helps social innovators to use fruitful friction as a strategy
to scale deep. The current study adds a new viewpoint to the scaling deep context and presents a concrete starting point of the scaling deep strategy by linking it with the creation of common ground.","Social Innovation; Multi-stakeholder collaboration; Common ground; Scaling deep; Framing","en","conference paper","","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:ce4d79aa-02e7-4026-92c3-ff8dacb35d4d","http://resolver.tudelft.nl/uuid:ce4d79aa-02e7-4026-92c3-ff8dacb35d4d","Off to new shores: Sailing towards common ground","Buckenmayer, M.B. (Student TU Delft); Gonçalves, M. (TU Delft Methodologie en Organisatie van Design); Mulder, I. (TU Delft Design Conceptualization and Communication)","","2021","“Off to new shores!” is a two-hour, interactive online workshop, participants will sail together to common ground and co-create a shared understanding of central concepts regarding a provided case. Participants learn and apply the concept of fruitful friction and use the metaphor of sailing. Fruitful friction is a concept that deliberately triggers people to express their implicit perspectives to create openness and awareness about different aspects that are usually not put on the table.","","en","conference paper","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:0d6c9d8c-a0fe-4de1-80cd-9ed4d9bd7cac","http://resolver.tudelft.nl/uuid:0d6c9d8c-a0fe-4de1-80cd-9ed4d9bd7cac","Towards value-creating and sustainable open data ecosystems: A comparative case study and a research agenda","van Loenen, B. (TU Delft Urban Data Science); Zuiderwijk-van Eijk, A.M.G. (TU Delft Information and Communication Technology); Vancauwenberghe, G. (Katholieke Universiteit Leuven); Lopez-Pellicer, Francisco J. (Universidad de Zaragoza); Mulder, I. (TU Delft Design Conceptualization and Communication); Alexopoulos, Charalampos (University of the Aegean); Magnussen, Rikke (Aalborg University); Saddiqa, Mubashrah (Aalborg University); Dulong de Rosnay, Melanie (CNRS); Crompvoets, Joep (Katholieke Universiteit Leuven); Pollini, Andrea (University of Camerino); Re, Barbara (University of Camerino); Casiano Flores, Cesar (Katholieke Universiteit Leuven)","","2021","Current open data systems lag behind in their promised value creation and sustainability. The objective of the current study is twofold: 1) to investigate whether existing open data systems meet the requirements of open data ecosystems, and 2) to develop a research agenda that discusses the gaps between current open data systems on the one hand and participatory, value-creating, sustainable open data ecosystems on the other hand. The literature reveals that the main characteristics of value-creating, sustainable open data ecosystems are user-drivenness, inclusiveness, circularity, and skill-based. Our comparative case study of five open data systems in various application domains and countries highlighted that none of these systems are real open data ecosystems: they often do not balance open data supply and demand, exclude specific user groups and domains, are linear, and lack skill-training. We elaborate on a research agenda that discusses how research should address the challenge of making open data ecosystems more value-generating and sustainable.","Open data ecosystem; open data; research agenda; inclusive; circular; user driven","en","journal article","","","","","","","","","","","Urban Data Science","","",""
"uuid:a346ecd0-6636-4603-b5ab-b6a7ee81b277","http://resolver.tudelft.nl/uuid:a346ecd0-6636-4603-b5ab-b6a7ee81b277","Beach-dune modelling in support of Building with Nature for an integrated spatial design of urbanized sandy shores","Wijnberg, Kathelijne (University of Twente); Poppema, Daan (University of Twente); Mulder, Jan (University of Twente); van Bergen, J. (TU Delft Landscape Architecture); Campmans, Geert (University of Twente); Galiforni-Silva, Filipe (University of Twente); Hulscher, Suzanne J.M.H. (University of Twente); Pourteimouri, Paran (University of Twente)","","2021","The long-term physical existence of sandy shores critically depends on a balanced sediment budget. From the principles of Building with Nature it follows that a sustainable protection of sandy shores should employ some form of shore nourishment. In the spatial design process of urbanized sandy shores, where multiple functions must be integrated, the knowledge and the prediction of sediment dynamics and beach-dune morphology thus play an essential role. This expertise typically resides with coastal scientists who have condensed their knowledge in various types of morphological models that serve different purposes and rely on different assumptions, thus have their specific strengths and limitations. This paper identifies morphological information needs for the integrated spatial design of urbanized sandy shores using BwN principles, outlines capabilities of different types of morphological models to support this and identifies current gaps between the two. A clear mismatch arises from the absence of buildings and accompanying human activities in current numerical models simulating morphological developments in beach-dune environments.","Beach-dune modelling; Building with nature; Coastal spatial design; Urbanized shore; Wind-driven sediment dynamics","en","journal article","","","","","","Vol. 7 (2021): Building with Nature perspectives: Cross-disciplinary BwN approaches in coastal regions. ISBN 978-94-6366-379-3","","","","","Landscape Architecture","","",""
"uuid:21e502d0-ee85-4ebc-8b42-7e2d490f260f","http://resolver.tudelft.nl/uuid:21e502d0-ee85-4ebc-8b42-7e2d490f260f","Flying by Feeling: Communicating Flight Envelope Protection through Haptic Feedback","van Baelen, D. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Ellerbroek, Joost (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Human-Robot Interaction); Mulder, Max (TU Delft Control & Simulation)","","2021","Modern aircraft can be equipped with a flight envelope protection system: automation which modifies pilot control inputs to ensure that the aircraft remains within the allowable limits. Overruling the pilot inputs may lead to mode confusion, even when visual or auditory feedback is provided to alert pilots. We advocate using active control devices to make the flight envelope protection system tangible to the pilot. This paper presents the main findings of an evaluation of three haptic feedback designs for flight envelope protection. The first concept used both force feedback and vibro-tactile alerts, producing promising, yet inconclusive, results. The second concept used asymmetric vibrations to give directional alerting cues, which did not result in improved performance on initial use, but which did yield improved learning rate for the task. The third system employed force feedback to physically guide the pilot away from flight envelope limits, which yielded safety improvements from the first use, but created dependence: pilot performance degraded immediately after the force feedback was removed. From this, we advise to use asymmetric vibrations during training for flight envelope excursions, to leverage active control interfaces for providing force feedback during operation, and reevaluate a combination of both to combine their advantages for single-pilot operations.","","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:c696b5cc-e7e8-4abd-83b1-627b8370961a","http://resolver.tudelft.nl/uuid:c696b5cc-e7e8-4abd-83b1-627b8370961a","Urban dunes: Towards BwN design principles for dune formation along urbanized shores","van Bergen, J. (TU Delft Landscape Architecture); Mulder, J. (University of Twente); Nijhuis, S. (TU Delft Landscape Architecture); Poppema, D. (University of Twente); Wijnberg, K. (University of Twente); Kuschnerus, M. (TU Delft Optical and Laser Remote Sensing)","","2021","Sandy shores worldwide suffer from coastal erosion due to a lack of sediment input and sea-level rise. In response, coastal sand nourishments are executed using ‘Building with Nature’ techniques (BwN), in which the sand balance is amplified and natural dynamics are instrumental in the redistribution of sand, cross- and alongshore. These nourishments contribute to the growth of beaches and dunes, serving various design objectives (such as flood safety, nature, and recreation). Nevertheless, human interference (such as buildings and traffic) along urbanized sandy shores may have significant, yet poorly understood, effects on beach and dune development. Better insight is required into the interplay of morphological, ecological and urban processes to support Aeolian BwN processes for dune formation and contribute to the sustainable design of urbanized coastal zones. This paper aims to bridge the gap between coastal engineering and urban design by formulating design principles for BwN along urbanized sandy shores, combining nourishments, natural dune formation and urban development on a local scale to strengthen the coastal buffer. The first part of the paper analyses sedimentation processes in the (built) sea-land interface and identifies spatial mechanisms that relate coastal occupation to dune formation. Hence a preliminary set of design principles is derived by manipulating wind-driven sediment transport for BwN dune formation after nourishment. In the second part of the paper, these principles are applied and contextualized in two case-studies to compare their capability for BwN in different coastal profiles: the vast, rural, geomorphologically high dynamic profile of a mega-nourishment (Sand Motor); versus the compact, highly urbanized, profile(s) of a coastal resort (Noordwijk). Conclusions reflect on the applicability of BwN design principles within different coastal settings (dynamics, urbanity) and spatial arrangements facilitating BwN dune formation.","Building with Nature; Nourishment; dune formation; urban coast; design principles","en","journal article","","","","","","Vol. 7 (2021): Building with Nature perspectives: Cross-disciplinary BwN approaches in coastal regions. ISBN 978-94-6366-379-3","","","","","Landscape Architecture","","",""
"uuid:e4f0458f-cc2e-4e11-8d49-2ab7f4b82328","http://resolver.tudelft.nl/uuid:e4f0458f-cc2e-4e11-8d49-2ab7f4b82328","The Skill Assumption: Over-Relicance on Perception Skills in Hazard Analysis","van Paassen, M.M. (TU Delft Control & Simulation); Reitsma, J.P. (TU Delft Control & Simulation); Huijbrechts, Erik-Jan A. M. (KLM Royal Dutch Airlines); Borst, C. (TU Delft Control & Simulation); Landman, H.M. (TU Delft Control & Simulation; TNO); Mulder, Max (TU Delft Control & Simulation)","","2021","In the analysis of human performance and human error, considerable attention is given to the cognitive processes of actors involved in error or success scenarios. Even with awareness of hindsight bias, it takes effort to understand the actions of agents in later inspection of error scenarios. One such topic of heated discussion was the perceived poor performance of pilots in the two 737 MAX MCAS-related crashes in applying the “memory item” checklist pertaining to a runaway trim. In this paper, we argue that it is not so much the reproduction of the checklist that was lacking in these scenarios, but the trigger for even starting the checklist. Not only trim run-away problems, but several other issues likewise require an instant reaction from pilots, designated as “memory items”. Rasmussen’s simplified schematic for the “skill, rule and knowledge” taxonomy already provides the tools for properly analyzing this. The skill to provide the triggers for these reactions relies on pattern extraction from the available sensory input, and, importantly, it can only be learned in a valid training context. It is argued that re-appraisal of these items is needed, addressing explicitly the validity of the training environments that enable pilots to learn the required pattern recognition skills.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:a7c86a48-8b63-4051-a818-4e471cc8aa77","http://resolver.tudelft.nl/uuid:a7c86a48-8b63-4051-a818-4e471cc8aa77","Flight Allocation in Shared Human-Automation En-Route Air Traffic Control","de Rooij, G. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2021","Allocation is a challenge for higher levels of automation in air traffic control, where flights can be dynamically assigned to either a human or an automated agent. Through an exploratory experiment with six professional air traffic controllers, insight was gained into the possibilities and challenges of human-automation teamwork in an en-route environment. Participants showed high levels of automation trust, but mostly ignored automation-suggested allocations, preferring a highly automated sector instead. Most flights were delegated to automation, after they were given a direct and conflict-free path. Flights handled manually were those requiring level changes or non-standard routing. Future research should focus on establishing specifically which flights can be automated.","Air traffic control; Human-automation interaction","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:35a5591a-fc65-4641-9a0c-d239f71a6d28","http://resolver.tudelft.nl/uuid:35a5591a-fc65-4641-9a0c-d239f71a6d28","Modelling dynamic fault slip and seismic wavefield for production-induced seismicity in Groningen","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2021","Induced seismicity from a gas-producing region such as Groningen is believed to be caused by reservoir depletion due to long-term gas production. However, because of the complexity and uncertainty regarding the underground structure and composition, it is difficult to quantify the effect on induced seismicity due to gas production. Here we use finite-element modelling to investigate the seismogenic potential of a pre-existing fault reactivated due to fluid depletion, considering different model settings. By applying quasi-static poroelastic loading representing reservoir depletion, the stress and strain fields are derived from the resulting displacement field. The equilibrium of the fault is then evaluated using either rate-and-state or slip-weakening behaviour for friction. When the critical state is reached on the fault, where the shear stress is greater than the friction, the reactivation of the fault takes place. This reactivation is simulated by using a dynamic solver to observe the propagation and the arrest of the dynamic faulting, as well as the resultant wavefield due to seismic slip. By comparing the depletion value at both aseismic and seismic ruptures, and looking at the stress distribution on the fault, the pattern of rupture nucleation, and the resulting seismic wavefield, we are able to evaluate separately the effect of different model settings, including the geometry and material property of both caprock and reservoir, reservoir depletion pattern, and the friction law. Furthermore, by combining our study with the observed seismic wavefield, it is possible to obtain useful insights on the spatial variation in the source region.","","en","poster","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:f1cf2912-b639-4a5c-9bb5-5c26ceb445e6","http://resolver.tudelft.nl/uuid:f1cf2912-b639-4a5c-9bb5-5c26ceb445e6","Modelling dynamic fault slip and seismic wavefield for production-induced seismicity in Groningen","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2021","Induced seismicity from a gas-producing region such as Groningen is believed to be caused by reservoir depletion due to long-term gas production. However, because of the complexity and uncertainty regarding the underground structure and composition, it is difficult to quantify the effect on induced seismicity due to gas production. Here we use finite-element modelling to investigate the seismogenic potential of a pre-existing fault reactivated due to fluid depletion, considering different model settings. By applying quasi-static poroelastic loading representing reservoir depletion, the stress and strain fields are derived from the resulting displacement field. The equilibrium of the fault is then evaluated using either rate-and-state or slip-weakening behaviour for friction. When the critical state is reached on the fault, where the shear stress is greater than the friction, the reactivation of the fault takes place. This reactivation is simulated by using a dynamic solver to observe the propagation and the arrest of the dynamic faulting, as well as the resultant wavefield due to seismic slip. By comparing the depletion value at both aseismic and seismic ruptures, and looking at the stress distribution on the fault, the pattern of rupture nucleation, and the resulting seismic wavefield, we are able to evaluate separately the effect of different model settings, including the geometry and material property of both caprock and reservoir, reservoir depletion pattern, and the friction law. Furthermore, by combining our study with the observed seismic wavefield, it is possible to obtain useful insights on the spatial variation in the source region.","","en","abstract","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:f4ed2bee-28fc-4cd1-a04e-d382249faf8a","http://resolver.tudelft.nl/uuid:f4ed2bee-28fc-4cd1-a04e-d382249faf8a","A numerically exact nonreflecting boundary condition applied to the acoustic Helmholtz equation","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2021","ABSTRACTWhen modeling wave propagation, truncation of the computational domain to a manageable size requires nonreflecting boundaries. To construct such a boundary condition on one side of a rectangular domain for a finite-difference discretization of the acoustic wave equation in the frequency domain, the domain is extended on that one side to infinity. Constant extrapolation in the direction perpendicular to the boundary provides the material properties in the exterior. Domain decomposition can split the enlarged domain into the original one and its exterior. Because the boundary-value problem for the latter is translation-invariant, the boundary Green functions obey a quadratic matrix equation. Selection of the solvent that corresponds to the outgoing waves provides the input for the remaining problem in the interior. The result is a numerically exact nonreflecting boundary condition on one side of the domain. When two nonreflecting sides have a common corner, the translation invariance is lost. Treating each side independently in combination with a classic absorbing condition in the other direction restores the translation invariance and enables application of the method at the expense of numerical exactness. Solving the quadratic matrix equation with Newton?s method turns out to be more costly than solving the Helmholtz equation and may select unwanted incoming waves. A proposed direct method has a much lower cost and selects the correct branch. A test on a 2D acoustic marine seismic problem with a free surface at the top, a classic second-order Higdon condition at the bottom, and numerically exact boundaries at the two lateral sides demonstrates the capability of the method. Numerically exact boundaries on each side, each computed independently with a free-surface or Higdon condition, provide even better results.","","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:1466625e-5b5d-46f0-a02c-386a1ad7a7fc","http://resolver.tudelft.nl/uuid:1466625e-5b5d-46f0-a02c-386a1ad7a7fc","Optimized Expansion Strategy for a Hydrogen Pipe Network in the Port of Rotterdam with Compound Real Options Analysis","van den Boomen, M. (TU Delft Integral Design & Management; Rotterdam University of Applied Sciences); Van der Meulen, Sjoerd (Rotterdam University of Applied Sciences; HAN University of Applied Sciences); Van Ekris, Jonathan (Rotterdam University of Applied Sciences); Spanjers, Roel (Rotterdam University of Applied Sciences); Ten Voorde, Olle (Rotterdam University of Applied Sciences); Mulder, Janwin (Rotterdam University of Applied Sciences); Blommaart, Peter (Rotterdam University of Applied Sciences)","","2021","br/>The port of Rotterdam is the largest seaport in Europe. To maintain its position, the harbor will have to anticipate global transitions such as transferring to sustainable energy. Hydrogen is seen as a promising energy carrier; however, future demand is uncertain. The current research investigates decision making under uncertainty and values flexibility. Compound real options analysis is applied to optimize the time-variant expansion strategies for a hydrogen pipe network. The trade-off between early investments and missed revenues when not investing in time determines the optimized expansion strategy. Moreover, the real options approach also provides the levelized unit price for hydrogen distribution, to cover the life cycle costs of the optimal expansion strategy. Finally, this real options approach offers flexibility to a decision maker as it allows for enhancing future decisions. The academic contribution of this research is a distinct perspective on a compound real options approach where the optimal strategic path is the key result of interest. This in contrast to other real options applications in the literature which focus on option value, exchange with limiting the options or do not visualize a strategic path. Moreover, this research demonstrates how stepwise expansion and decision making under uncertainty facilitate transitions such as the transition toward clean energy.","real options analysis; expansion; compound options; adaptive decision making; uncertainty","en","journal article","","","","","","","","","","","Integral Design & Management","","",""
"uuid:e85c634d-ddf6-4ba3-98cd-67421445118f","http://resolver.tudelft.nl/uuid:e85c634d-ddf6-4ba3-98cd-67421445118f","Operationalizing Framing to Support Multiperspective Recommendations of Opinion Pieces","Mulder, M. (Student TU Delft); Inel, O. (TU Delft Web Information Systems); Oosterman, J.E.G. (Blendle); Tintarev, N. (Universiteit Maastricht)","","2021","Diversity in personalized news recommender systems is often defined as dissimilarity, and operationalized based on topic diversity (e.g., corona versus farmers strike). Diversity in news media, however, is understood as multiperspectivity (e.g., different opinions on corona measures), and arguably a key responsibility of the press in a democratic society. While viewpoint diversity is often considered synonymous with source diversity in communication science domain, in this paper,we take a computational view.We operationalize the notion of framing, adopted from communication science. We apply this notion to a re-ranking of topic-relevant recommended lists, to form the basis of a novel viewpoint diversification method. Our offline evaluation indicates that the proposed method is capable of enhancing the viewpoint diversity of recommendation lists according to a diversity metric from literature. In an online study, on the Blendle platform, a Dutch news aggregator, with more than 2000 users, we found that users are willing to consume viewpoint diverse news recommendations.We also found that presentation characteristics significantly influence the reading behaviour of diverse recommendations. These results suggest that future research on presentation aspects of recommendations can be just as important as novel viewpoint diversification methods to truly achieve multiperspectivity in online news environments.","Framing aspects; Recommender systems; Viewpoint diversity","en","conference paper","","","","","","","","","","","Web Information Systems","","",""
"uuid:74d45c2f-1532-4455-9c8b-ea6358706910","http://resolver.tudelft.nl/uuid:74d45c2f-1532-4455-9c8b-ea6358706910","Neutron Diffraction Study of a Sintered Iron Electrode In Operando","Weninger, B. (TU Delft ChemE/Materials for Energy Conversion and Storage); Thijs, M.A. (TU Delft RST/Neutron and Positron Methods in Materials); Nijman, Jeroen A.C. (Independent researcher); van Eijck, L. (TU Delft RST/Neutron and Positron Methods in Materials); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2021","Iron is a promising, earth-abundant material for future energy applications. In this study, we use a neutron diffractometer to investigate the properties of an iron electrode in an alkaline environment. As neutrons penetrate deeply into materials, neutron scattering gives us a unique insight into what is happening inside the electrode. We made our measurements while the electrode was charging or discharging. Our key questions are: Which phases occur for the first and second discharge plateaus? And why are iron electrodes less responsive at higher discharge rates? We conclude that metallic iron and iron hydroxide form the redox pair for the first discharge plateau. For the second discharge plateau, we found a phase similar to feroxyhyte but with symmetrical and equally spaced arrangement of hydrogen atoms. The data suggest that no other iron oxide or iron (oxy)hydroxide formed. Remarkable findings include the following: (1) substantial amounts of iron hydroxide are always present inside the electrode. (2) Passivation is mostly caused by iron hydroxide that is unable to recharge. (3) Iron fractions change as expected, while iron hydroxide fractions are delayed, resulting in substantial amounts of
amorphous, undetectable iron phases. About 40% of the participating iron of the first plateau and about 55% of the participating iron for the second plateau are undetectable. (4) Massive and unexpected precipitation of iron hydroxide occurs in the transition from discharging to charging. (2), (3), and (4) together cause accumulation of iron hydroxide inside the electrode.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:2aff786f-35b1-42ad-9065-2837a77e75a8","http://resolver.tudelft.nl/uuid:2aff786f-35b1-42ad-9065-2837a77e75a8","Modeling the Performance of an Integrated Battery and Electrolyzer System","Mangel Raventos, A. (TU Delft Large Scale Energy Storage); Kluivers, Gerard J. (Student TU Delft); Haverkort, J.W. (TU Delft Energy Technology); de Jong, W. (TU Delft Large Scale Energy Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Kortlever, R. (TU Delft Large Scale Energy Storage)","","2021","Both daily and seasonal fluctuations of renewable power sources will require large-scale energy storage technologies. A recently developed integrated battery and electrolyzer system, called battolyser, fulfills both time-scale requirements. Here, we develop a macroscopic COMSOL Multiphysics model to quantify the energetic efficiency of the battolyser prototype that, for the first time, integrates the functionality of a nickel-iron battery and an alkaline electrolyzer. The current prototype has a rated capacity of 5 Ah, and to develop a larger, enhanced system, it is necessary to characterize the processes occurring within the battolyser and to optimize the individual components of the battolyser. Therefore, there is a need for a model that can provide a fast screening on how the properties of individual components influence the overall energy efficiency of the battolyser prototype. The model is validated using experimental results, and new configurations are compared, and the energy efficiency is optimized for the scale-up of this lab-scale device. Based on the modeling work, we find an optimum electrode thickness for the nickel electrode of 3 and 2.25 mm for the iron electrode with optimal electrode porosities in the range of void fraction of 0.15-0.35. Additionally, electrolyte conductivity and the gap thickness are found to have a small effect on the overall efficiency of the device.","","en","journal article","","","","","","","","","","","Large Scale Energy Storage","","",""
"uuid:a0896e68-49eb-4f0d-8377-64c26fd9e101","http://resolver.tudelft.nl/uuid:a0896e68-49eb-4f0d-8377-64c26fd9e101","Supporting Urban Innovators’ Reflective Practice","Magni, A. (TU Delft Design Conceptualization and Communication); Calderon Gonzalez, A. (TU Delft Design Conceptualization and Communication); Mulder, I. (TU Delft Design Conceptualization and Communication)","Mealha, Óscar (editor); Dascalu, Mihai (editor); Di Mascio, Tania (editor)","2021","Over the past years, a growing number of local initiatives are generating solutions for societal challenges in their cities. However, the scale and complexity of these challenges force urban innovators to constantly adapt and learn, having to acquire new capabilities that will help them advance towards systemic change. In the current work, we take the premise that these urban innovators need to be able to utilise the urban context as a learning ecosystem in order to push their interventions beyond the boundaries of small innovative niches. In keeping with Schön’s reflective practice, we envisage reflection as a core competence for these urban change makers to grow and present a reflective process supporting urban innovators in framing their professional learning journey to succeed in their projects. A series of online sessions have been conducted to investigate how to scaffold a reflective process enabling innovators to better identify challenges in their projects and the corresponding capabilities they need to acquire. In the proposed paper, we present reflective activities as a tool supporting urban innovators in self-defining their learning journeys and elaborate on the insights gained. It can be concluded that the reflective process we developed was valuable to urban innovators in unveiling new learning needs for their projects, while further research is needed to more effectively translate these learnings into actionable steps to sustain innovators’ self-development.","Design; Learning ecosystems; Reflection; Self-development; Societal challenges; Urban innovators","en","conference paper","Springer Nature","","","","","Accepted Author Manuscript","","2022-08-31","","","Design Conceptualization and Communication","","",""
"uuid:29eb7ce0-aa66-408d-abc6-9887dc266ac3","http://resolver.tudelft.nl/uuid:29eb7ce0-aa66-408d-abc6-9887dc266ac3","Groene kades langs de Nieuwe Mark","Dijkhuis, Edwin (Floron - Plant Conservation Netherlands); Mulder, K.B. (TU Delft Architectural Technology); Lubelli, B. (TU Delft Heritage & Architecture)","","2021","Aan de zuidwestzijde van de binnenstad van Breda ligt de deels gedempte rivier de Mark. Deze wordt de komende jaren uitgegraven en getransformeerd tot een blauwgroene ader: de Nieuwe Mark. De Nieuwe Mark moet straks de lokale ecologie verstevigen en het stedelijk klimaat verbeteren. Onderdeel van deze natuurinclusieve transformatie is het realiseren van met muurplanten begroeide kademuren. Wat daar technisch voor nodig is wordt momenteel onderzocht binnen het GreenQuays project.","quay wall; Green wall","nl","journal article","","","","","","","","","","","Heritage & Architecture","","",""
"uuid:efa91ae6-a7a0-4e29-b806-7de1f629e2d1","http://resolver.tudelft.nl/uuid:efa91ae6-a7a0-4e29-b806-7de1f629e2d1","Evaluating Stick Stiffness and Position Guidance for Feedback on Flight Envelope Protection","van Baelen, D. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Ellerbroek, Joost (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Human-Robot Interaction); Mulder, Max (TU Delft Control & Simulation)","","2021","Modern aircraft use a variety of fly-by-wire control devices and combine these with a flight envelope protection system to limit pilot control inputs when approaching the aircraft limits. The current research project aims to increase pilot awareness of such a protection system through the use of force feedback on the control device, i.e., haptics. A previous design used asymmetric vibrations to cue the pilot on the flight envelope. The evaluation showed no improvement in metrics at the first emergency encounter, yet did show a potential training benefit. Therefore, a new haptic feedback concept was designed with the specific aim to guide the pilot when approaching a limit and provide support from the first time use. This paper evaluates these haptic feedback designs with 36 active PPL/LAPL pilots who flew a challenging vertical profile and encountered a windshear in a fixed-base simulator. The pilots were divided in three groups who received either cueing, guidance, or no haptic feedback. It was hypothesized that: (i) cueing haptic feedback provides a faster learning rate compared to no-haptics, and (ii) guidance haptic feedback results in best performance from the first run yet worse metrics when no feedback is provided. Comparing the results of the cueing and no-haptic feedback groups confirmed the first hypothesis. Results also showed that the guidance haptic feedback resulted in improved metrics at the first run, and the worsening of metrics when no longer provided.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Virtual/online event due to COVID-19","","","","","Control & Simulation","","",""
"uuid:97b4441c-4c48-42eb-8c3c-d2d454951769","http://resolver.tudelft.nl/uuid:97b4441c-4c48-42eb-8c3c-d2d454951769","Perceptual Eigenmode Distortion Analysis for Motion Cueing Evaluation in Fixed-Wing Aircraft Simulators","Tillema, G.H.J. (Student TU Delft); Stroosma, O. (TU Delft Control & Simulation); Miletović, I. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2021","The Perceptual Eigenmode Distortion (PEMD), an extension to the Eigenmode Distortion (EMD), is a method for objectively evaluating simulator motion fidelity, developed over the last few years. EMD assesses how the Motion Cueing Algorithm (MCA) distorts the vehicle's perceived eigenmodes. In this paper, EMD is extended by a human perception model, which helps to balance the various motion cue contributions in a more human-centered context. Additionally, a new automatic MCA tuning approach is introduced to create an MCA parameter set that is optimal in terms of eigenmode distortion. The method is applied to a combined linear model of the Cessna Citation 500 for asymmetrical flight and the Classical Washout Algorithm (CWA). A pilot-in-the-loop experiment was performed, with six pilots in the SIMONA Research Simulator, to compare the PEMD method's parameter set with sets designed with the current state-of-the-art method of the Objective Motion Cueing Test (OMCT), and with a baseline motion configuration, as well as a condition without any simulator motion. Throughout each run of the double-blind pairwise comparisons, the Dutch roll eigenmode was externally excited with a gust of semi-random amplitude and direction. Two hypotheses were tested using subjective preferences and through measuring the Dutch roll suppression performance. Subjective preferences varied between and within pilots, and similar results for PEMD and OMCT were found. A significant improvement in performance was found, however, between the no-motion condition and the PEMD. Although the perceived differences between a PEMD-tuned and alternative MCA settings seem very subtle, the improved mode suppression performance suggests the method having merit in flight scenarios where the aircraft's dynamic modes play an important role.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Virtual/online event due to COVID-19","","","","","Control & Simulation","","",""
"uuid:1f648dbb-d8b0-4a31-a658-e93ccec9e181","http://resolver.tudelft.nl/uuid:1f648dbb-d8b0-4a31-a658-e93ccec9e181","A Procedure for Inducing the Leans Illusion in a Hexapod Motion Simulator","Landman, H.M. (TNO); van den Hoed, Annemarie (Cognizant Technology Solutions); van Baelen, D. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Groen, Eric L. (TNO); Mulder, Max (TU Delft Control & Simulation)","","2021","Ground-based demonstration of spatial disorientation (SD) has been recommended for military as well as commercial pilot training. Although the leans illusion is the most common form of SD, no data exist yet of an effective ground-based leans procedure for a hexapod simulator. In this paper we describe the development of such a procedure and its tuning with nine subjects. The procedure was then used in an experiment with 18 airline pilots, which is described elsewhere. The final procedure started with a prepositioning phase, during which the simulator platform was slowly tilted to a 3.5° prepositioning roll angle, while the pilot performed a distraction task and the instruments and outside visuals indicated level flight. Next followed an adaptation phase, during which the pilot's vestibular system adapted to the new angle, the outside visibility degraded to zero and the instruments were covered. Then the platform was moved back to level, above the perceptual threshold, after which the instruments were shown again. The pilot was then tasked to roll back to level. The addition of the motion cues caused an increase in roll reversal errors by a factor of 3 in airline pilots. The procedure can be implemented in a scenario for demonstrating the leans in a cost-effective simulator.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Virtual/online event due to COVID-19","","","","","Control & Simulation","","",""
"uuid:b5c27afb-fe6a-4368-8cb7-dcf81d5d69ae","http://resolver.tudelft.nl/uuid:b5c27afb-fe6a-4368-8cb7-dcf81d5d69ae","Linear Mixed-Effects Models for Human-in-the-Loop Tracking Experiment Data","Zaal, P.M.T. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2021","Linear mixed-effects models provide several benefits over more traditional statistical inference tests and are particularly useful for most human-in-the-loop tracking experiment data. However, surprisingly, mixed models are virtually not used for the analysis of tracking experiment data. This paper uses linear mixed-effects models to analyze combined tracking data from two previous human-in-the-loop roll tracking experiments that compared control behavior metrics collected in both a research aircraft and a motion-base simulator. In the experiments, pilots' behavior under 10 different motion configurations with varying motion filter gains and break frequencies was evaluated and compared to that in the real aircraft. The linear mixed-effects model analysis on the combined dataset confirmed the main statistical outcomes of the individual experiments. The main benefits of mixed models for this type of data were demonstrated by successfully combining data from two experiments that used different experimental conditions and of which one had an additional apparatus and the other a missing participant. Finally, the mixed-model analysis was able to explicitly test for scientifically relevant statistical differences in the dependent measures between the aircraft and simulator, as well as between both experiments.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Virtual/online event due to COVID-19","","","","","Control & Simulation","","",""
"uuid:4fe45f67-1d4d-43a7-91f4-1d215f2db456","http://resolver.tudelft.nl/uuid:4fe45f67-1d4d-43a7-91f4-1d215f2db456","Grading 600+ students: A Case Study on Peer and Self Grading","Aniche, Maurício (TU Delft Software Engineering); Mulder, F. (TU Delft Computer Science & Engineering-Teaching Team); Hermans, Felienne (Universiteit Leiden)","O'Conner, L. (editor)","2021","Grading large classes has become a challenging and expensive task for many universities. The Delft University of Technology (TU Delft), located in the Netherlands, has observed a large increase in student numbers over the past few years. Given the large growth of the student population, grading all the submissions results in high costs. We made use of self and peer grading in the 2018-2019 edition of our software testing course. Students worked in teams of two, and self and peer graded three assignments in our course. We ended up with 906 self and peer graded submissions, which we compared to 248 submissions that were graded by our TAs. In this paper, we report on the differences we observed between self, peer, and TA grading. Our findings show that: (i) self grades tend to be 8-10% higher than peer grades on average, (ii) peer grades seem to be a good approximator of TA grades; in cases where self and peer grade differ significantly, the TA grade seems to lie in between, and (iii) the gender and the nationality of the student do not seem to affect self and peer grading.","computer science education; peer grading; self grading","en","conference paper","IEEE","","","","","Accepted author manuscript","","","","","Software Engineering","","",""
"uuid:6fc02e4b-da4f-4fbe-802a-74b793686a40","http://resolver.tudelft.nl/uuid:6fc02e4b-da4f-4fbe-802a-74b793686a40","Quantifying automatable checklist items on a commercial flightdeck","Reitsma, J.P. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2021","In-flight non-normal events can be rather taxing for a flight crew. Numerous tasks, often competing for attention, need to be handled adequately after which, the best plan of action for the remainder of the flight needs to be determined. In the light of recent developments towards reduced crew operations, the demand for reducing workload has become apparent. This requires us to rethink the role of the pilot, which to the authors perspective is mainly one of a flying and flight plan manager. System management is a function that can be assigned to automation. Automation on modern plane often already monitors systems more accurate and faster than pilots can every do. However, in this study we explore the potential checklist step reduction if, the automation will go one step further. Namely, automatically execute reconfiguration steps that do not affect flight characteristic. In total, 39% of the checklist items are potential candidates for this new automation. Average checklist size can be reduced to 4, compared to the current average of 6.5 items per checklists. This result does not provide us with an estimated time saving. Although, the result seems promising to reduce the workload on the flight crew. This exploration can be followed-up by a study to estimate the potential time savings. Besides this improvements can be made to reduce the length of the informative statements and implications on the flight plan can be presented in a more efficient manner.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Virtual/online event due to COVID-19","","","","","Control & Simulation","","",""
"uuid:23814247-b55d-402a-a01c-14ebf238e40a","http://resolver.tudelft.nl/uuid:23814247-b55d-402a-a01c-14ebf238e40a","A Novel Automated Electronic Checklist for Non-Normal Event Resolution Tasks","Linskens, C.E. (Student TU Delft); Reitsma, J.P. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2021","Non-normal event resolution in-flight can be challenging on the flight crew with increased time pressure, workload, stress. Other competing tasks impose a risk on flight safety and burdens the decision-making process. Pilots rely on checklists to aid in their effort, which in its state-of-the-art form are presented on the dedicated Electronic Checklist (ECL) display for Boeing aircraft and on the Electronic Centralised Aircraft Monitor (ECAM) system for Airbus aircraft. However, human-induced errors and limitations remain prevalent. Exploring a different approach from other research efforts, this paper proposes a novel design which assumes automated checklist handling as a viable option to reduce workload durning nonnormal events. In a human-in-the-loop experiment with 12 commercial pilots, the design was compared against a reproduced Boeing 787 ECL over two scenarios. A synthetic setup was used, assuming a touch-based Boeing 737-8 flight deck combined with the Boeing 787 state-of-the-art alerting systems and displays. Results indicate significant checklist completion time reductions with the proposed design of 31.3% and 42.0% for an electrical and hydraulic failure, respectively. Experienced workload and situation awareness remained unchanged, though compressed in a shorter time frame. The novel display was positively anticipated by participants but was found to lack automation feedback.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Virtual/online event due to COVID-19","","","","","Control & Simulation","","",""
"uuid:9fe5c0ed-095d-48b4-b501-858b0e7fe03b","http://resolver.tudelft.nl/uuid:9fe5c0ed-095d-48b4-b501-858b0e7fe03b","Hybrid Approach for the Modeling of Magnetic Force Excitations in Multipole Wind Turbine Generators Considering Air Gap Imperfections","Kern, Alexander (Rheinisch-Westfälische Technische Hochschule); Mulder, Christoph (Rheinisch-Westfälische Technische Hochschule); Hameye, Kay (Rheinisch-Westfälische Technische Hochschule); Dong, J. (TU Delft DC systems, Energy conversion & Storage)","","2021","Magnetic force excitations in the air gap of generators can lead to tonal noise emissions of direct-drive wind turbines. Besides the magnetic circuit design, the generator air gap topology has an impact on the excited vibration modes and their frequencies, respectively. For the model-based analysis of the excited force density waves, the spatial and temporal distribution of the air gap magnetic flux density has to be modeled accurately, since it is directly linked with the interfacial forces by the Maxwell stress tensor. Electromagnetic simulations by finite elements consider nonlinear effects, as e.g. saturation, and are therefore convenient for the quantitative analysis. The processing of finite element meshes for the stated purpose is however cumbersome, since many full-models of huge structures (multipole) are necessary. Semi-analytical approaches using conformal maps are efficient for analyzing air gap deformations linearly, even though they do not consider the saturation behavior implicitly. In this work, an efficient hybrid approach for the modeling of force excitations by multipole generators considering air gap imperfection is presented. The calculation method combines electromagnetic 2D-finite-element results of symmetrical units with permeance functions of deformed air gaps obtained by conformal mapping to study the spatial and temporal shape of excited force density waves along the whole generator circumference.","Generators; Hybrid power systems; Acoustic Emission and Vibration; Modeling; Air Gap Imperfections; Nonuniform Air Gap","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-05-16","","","DC systems, Energy conversion & Storage","","",""
"uuid:892fb909-ed44-46b8-a4a6-ac3c1e97d800","http://resolver.tudelft.nl/uuid:892fb909-ed44-46b8-a4a6-ac3c1e97d800","Influence of brick and mortar properties on bioreceptivity of masonry: Results from experimental research","Lubelli, B. (TU Delft Heritage & Technology); Moerman, J. (TU Delft Design of Constrution); Esposito, R. (TU Delft Applied Mechanics); Mulder, K.B. (TU Delft Design of Constrution)","","2021","The effect of mortar and brick properties on the growth of ivy-leaved toadflax (Cymbalaria muralis) and yellow corydalis (Pseudofumaria lutea) has been investigated in laboratory. Different mortar compositions were designed and tested in combination with two different bricks. Highly porous bricks and mortars showed good bioreceptivity; mortars with lime-trass and, in lower extent, those with natural hydraulic lime binder, gave the best results in terms of bioreceptivity. The addition of vermiculite to the mortar was beneficial for plant growth. The brick-mortar combinations most favourable for plant growth were those with estimated low compressive and flexural bond strength values. Proposals are advanced for obtaining a compromise between mechanical strength and bioreceptivity.","Binder; Bioreceptivity; Brick; Mechanical strength; Mortar; Porosity","en","journal article","","","","","","","","","","","Heritage & Technology","","",""
"uuid:6c9387a8-88bf-488b-8126-d9456d03da75","http://resolver.tudelft.nl/uuid:6c9387a8-88bf-488b-8126-d9456d03da75","Nickel-iron layered double hydroxides for an improved Ni/Fe hybrid battery-electrolyser","Iranzo, A. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2021","The transition to renewable electricity sources and green feedstock implies the development of electricity storage and conversion systems to both stabilise the electricity grid and provide electrolytic hydrogen. We have recently introduced the concept of a hybrid Ni/Fe battery-electrolyser (battolyser) for this application1. The hydrogen produced during the Ni/Fe cell charge and continued electrolysis can serve as chemical feedstock and a fuel for long-term storage, while the hybrid battery electrodes provide short term storage. Here, we present Ni-Fe layered double hydroxides (NiFe-LDHs) for enhancing the positive electrode performance. The modified Ni(OH)2 material capacity, high rate performance and stability have been tested over a large range of charge rates (from 0.1C to 20C) over 1000 cycles. The Ni-Fe layered double hydroxides allow the capacity per nickel atom to be multiplied by 1.8 in comparison to the conventional β-Ni(OH)2 material which suggests that the nickel content can be reduced by 45% for the same capacity. This reduction of the nickel content is extremely important as this presents the most costly resource. In addition, Fe doped Ni(OH)2 shows improved ionic and electronic conductivity, OER catalytic activity outperforming the benchmark (Ir/C) catalyst, and long term cycling stability. The implementation of this Fe doped Ni(OH)2 material in the Ni/Fe hybrid battery-electrolyser will bring both electrolysis and battery function forward at reduced material cost and energy loss.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:8a5d8e67-65d8-4e81-b9fd-6d6d0744cac0","http://resolver.tudelft.nl/uuid:8a5d8e67-65d8-4e81-b9fd-6d6d0744cac0","The effect of building geometry on the size of aeolian deposition patterns: Scale model experiments at the beach","Poppema, Daan W. (University of Twente); Wijnberg, Kathelijne M. (University of Twente); Mulder, Jan P.M. (University of Twente); Vos, S.E. (TU Delft Coastal Engineering); Hulscher, Suzanne J.M.H. (University of Twente)","","2021","In sandy environments, like the beach-dune system, buildings not only affect the airflow, but also the aeolian sediment transport in their surroundings. In this study, we determine how the horizontal size of sediment deposition patterns around buildings depends on the building's dimensions. Four one-day experiments were conducted at the beach using box-shaped scale models. We tested 32 building geometries, where scale model height, width and length ranged between 0.3 and 2.0 m. The deposition patterns were substantial in size: the total length and width of the deposition area were up to an order of magnitude larger than the horizontal building dimensions. It was found that the size of upwind and downwind deposition patterns depended more on the building width perpendicular to the wind direction (w), than on the building height (h). Building length had little influence. Especially the combined effect of w and h correlated well with horizontal deposition size. This is expressed in a new scaling length B for deposition around buildings, with B=w2/3·h1/3. As a first validation, the spatial dimensions of the initial deposition patterns observed around a scale model of 2.5 × 12 × 2.5 m, placed at the beach for five weeks, showed good agreement with those predicted based on B.","Characteristic length scale; Obstacles to wind flow; Roughness element; Sand drift; Structure-from-motion photogrammetry; Urbanized beach","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:2c7af185-6da3-45ed-8bb8-d1891340d336","http://resolver.tudelft.nl/uuid:2c7af185-6da3-45ed-8bb8-d1891340d336","Estimating instantaneous sea-ice dynamics from space using the bi-static radar measurements of Earth Explorer 10 candidate Harmony","Kleinherenbrink, M. (TU Delft Mathematical Geodesy and Positioning); Korosov, Anton (Nansen Environmental and Remote Sensing Center); Newman, Thomas (University College London (UCL)); Theodosiou, A. (TU Delft Mathematical Geodesy and Positioning); Komarov, Alexander S. (Environment Canada); Li, Y. (TU Delft Mathematical Geodesy and Positioning); Mulder, G. (TU Delft Mathematical Geodesy and Positioning); Rampal, Pierre (ENS-PSL Research University & CNRS); Stroeve, Julienne (University College London (UCL)); Lopez Dekker, F.J. (TU Delft Mathematical Geodesy and Positioning)","","2021","This article describes the observation techniques and suggests processing methods to estimate dynamical sea-ice parameters from data of the Earth Explorer 10 candidate Harmony. The two Harmony satellites will fly in a reconfigurable formation with Sentinel-1D. Both will be equipped with a multi-angle thermal infrared sensor and a passive radar receiver, which receives the reflected Sentinel-1D signals using two antennas. During the lifetime of the mission, two different formations will be flown. In the stereo formation, the Harmony satellites will fly approximately 300km in front and behind Sentinel-1, which allows for the estimation of instantaneous sea-ice drift vectors. We demonstrate that the addition of instantaneous sea-ice drift estimates on top of the daily integrated values from feature tracking have benefits in terms of interpretation, sampling and resolution. The wide-swath instantaneous drift observations of Harmony also help to put high-temporal-resolution instantaneous buoy observations into a spatial context. Additionally, it allows for the extraction of deformation parameters, such as shear and divergence. As a result, Harmony's data will help to improve sea-ice statistics and parametrizations to constrain sea-ice models. In the cross-track interferometry (XTI) mode, Harmony's satellites will fly in close formation with an XTI baseline to be able to estimate surface elevations. This will allow for improved estimates of sea-ice volume and also enables the retrieval of full, two-dimensional swell-wave spectra in sea-ice-covered regions without any gaps. In stereo formation, the line-of-sight diversity allows the inference of swell properties in both directions using traditional velocity bunching approaches. In XTI mode, Harmony's phase differences are only sensitive to the ground-range direction swell. To fully recover two-dimensional swell-wave spectra, a synergy between XTI height spectra and intensity spectra is required. If selected, the Harmony mission will be launched in 2028.","","en","journal article","","","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:c38e25c7-5a7f-4cc8-a0c6-79b5b847debd","http://resolver.tudelft.nl/uuid:c38e25c7-5a7f-4cc8-a0c6-79b5b847debd","Towards a synthetic cell cycle","Olivi, Lorenzo (Wageningen University & Research); Berger, Mareike (AMOLF); Creyghton, Ramon N.P. (Systems Biophysics; AMOLF); De Franceschi, N. (TU Delft BN/Cees Dekker Lab; Kavli institute of nanoscience Delft); Dekker, C. (TU Delft BN/Cees Dekker Lab; Kavli institute of nanoscience Delft); Mulder, Bela M. (AMOLF); Claassens, Nico J. (Wageningen University & Research); ten Wolde, Pieter Rein (AMOLF); van der Oost, John (Wageningen University & Research)","","2021","Recent developments in synthetic biology may bring the bottom-up generation of a synthetic cell within reach. A key feature of a living synthetic cell is a functional cell cycle, in which DNA replication and segregation as well as cell growth and division are well integrated. Here, we describe different approaches to recreate these processes in a synthetic cell, based on natural systems and/or synthetic alternatives. Although some individual machineries have recently been established, their integration and control in a synthetic cell cycle remain to be addressed. In this Perspective, we discuss potential paths towards an integrated synthetic cell cycle.","","en","review","","","","","","","","","","","BN/Cees Dekker Lab","","",""
"uuid:0f99b3eb-def8-4f7e-8ab6-443792760bd3","http://resolver.tudelft.nl/uuid:0f99b3eb-def8-4f7e-8ab6-443792760bd3","Ammonia Synthesis at Ambient Conditions via Electrochemical Atomic Hydrogen Permeation","Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Zaffaroni, R. (TU Delft ChemE/Materials for Energy Conversion and Storage); Schreuders, H. (TU Delft ChemE/O&O groep); Boshuizen, B. (TU Delft ChemE/O&O groep); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2021","Direct electrochemical nitrogen reduction holds the promise of enabling the production of carbon emission-free ammonia, which is an important intermediate in the fertilizer industry and a potential green energy carrier. Here we show a strategy for ambient condition ammonia synthesis using a hydrogen permeable nickel membrane/electrode that spatially separates the electrolyte and hydrogen reduction side from the dinitrogen activation and hydrogenation sites. Gaseous ammonia is produced catalytically in the absence of electrolyte via hydrogenation of adsorbed nitrogen by electrochemically permeating atomic hydrogen from water reduction. Dinitrogen activation at the polycrystalline nickel surface is confirmed with 15N2 isotope labeling experiments, and it is attributed to a Mars-van Krevelen mechanism enabled by the formation of N-vacancies upon hydrogenation of surface nitrides. We further show that gaseous hydrogen does not hydrogenate the adsorbed nitrogen, strengthening the benefit of having an atomic hydrogen permeable electrode. The proposed approach opens new directions toward green ammonia.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:86a7e909-1337-40be-9efa-5800c0b9797c","http://resolver.tudelft.nl/uuid:86a7e909-1337-40be-9efa-5800c0b9797c","Electrochemical p-Doping of CsPbBr3Perovskite Nanocrystals","Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); du Fossé, I. (TU Delft ChemE/Opto-electronic Materials); Alimoradi Jazi, M. (TU Delft ChemE/Opto-electronic Materials); Manna, L. (TU Delft ChemE/Opto-electronic Materials; Istituto Italiano di Tecnologia); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials)","","2021","Lead halide perovskite nanocrystals have drawn attention as active light-absorbing or -emitting materials for opto-electronic applications due to their facile synthesis, intrinsic defect tolerance, and color-pure emission ranging over the entire visible spectrum. To optimize their application in, e.g., solar cells and light-emitting diodes, it is desirable to gain control over electronic doping of these materials. However, predominantly due to the intrinsic instability of perovskites, successful electronic doping has remained elusive. Using spectro-electrochemistry and electrochemical transistor measurements, we demonstrate here that CsPbBr3 nanocrystals can be successfully and reversibly p-doped via electrochemical hole injection. From an applied potential of ∼0.9 V vs NHE, the emission quenches, the band edge absorbance bleaches, and the electronic conductivity quickly increases, demonstrating the successful injection of holes into the valence band of the CsPbBr3 nanocrystals.","perovskite; nanocrystal; electrochemical doping; CsPbBr3","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:748c3c46-f58b-4419-ada2-fecebf8e2695","http://resolver.tudelft.nl/uuid:748c3c46-f58b-4419-ada2-fecebf8e2695","Accelerating 1H NMR Detection of Aqueous Ammonia","Kolen, M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Smith, W.A. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2021","Direct electrolytic N2 reduction to ammonia (NH3) is a renewable alternative to the Haber-Bosch process. The activity and selectivity of electrocatalysts are evaluated by measuring the amount of NH3 in the electrolyte. Quantitative 1H nuclear magnetic resonance (qNMR) detection reduces the bench time to analyze samples of NH3 (present in the assay as NH4+) compared to conventional spectrophotometric methods. However, many groups do not have access to an NMR spectrometer with sufficiently high sensitivity. We report that by adding 1 mM paramagnetic Gd3+ ions to the NMR sample, the required analysis time can be reduced by an order of magnitude such that fast NH4+ detection becomes accessible with a standard NMR spectrometer. Accurate, internally calibrated quantification is possible over a wide pH range.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:f3e4533d-9311-4d2f-8640-b3cb805a38d4","http://resolver.tudelft.nl/uuid:f3e4533d-9311-4d2f-8640-b3cb805a38d4","Biosignatures of the Earth: I. Airborne spectropolarimetric detection of photosynthetic life","Patty, C. H.Lucas (University of Bern); Kühn, Jonas G. (University of Bern; Université de Genève); Lambrev, Petar H. (Biological Research Center); Spadaccia, Stefano (University of Bern); Keller, C.U. (TU Delft QN/Fysics of NanoElectronics; Universiteit Leiden); Mulder, W. (TU Delft Astrodynamics & Space Missions; Universiteit Leiden); Pallichadath, V. (TU Delft Astrodynamics & Space Missions); Snik, Frans (Universiteit Leiden); Stam, D.M. (TU Delft Astrodynamics & Space Missions)","","2021","Context. Homochirality is a generic and unique property of life on Earth and is considered a universal and agnostic biosignature. Homochirality induces fractional circular polarization in the incident light that it reflects. Because this circularly polarized light can be sensed remotely, it can be one of the most compelling candidate biosignatures in life detection missions. While there are also other sources of circular polarization, these result in spectrally flat signals with lower magnitude. Additionally, circular polarization can be a valuable tool in Earth remote sensing because the circular polarization signal directly relates to vegetation physiology. Aims. While high-quality circular polarization measurements can be obtained in the laboratory and under semi-static conditions in the field, there has been a significant gap to more realistic remote sensing conditions. Methods. In this study, we present sensitive circular spectropolarimetric measurements of various landscape elements taken from a fast-moving helicopter. Results. We demonstrate that during flight, within mere seconds of measurements, we can differentiate (S∕ N > 5) between grass fields, forests, and abiotic urban areas. Importantly, we show that with only nonzero circular polarization as a discriminant, photosynthetic organisms can even be measured in lakes. Conclusions. Circular spectropolarimetry can be a powerful technique to detect life beyond Earth, and we emphasize the potential of utilizing circular spectropolarimetry as a remote sensing tool to characterize and monitor in detail the vegetation physiology and terrain features of Earth itself.","Astrobiology; Earth; Planets and satellites: surfaces; Planets and satellites: terrestrial planets; Polarization; Techniques: polarimetric","en","journal article","","","","","","","","","","","QN/Fysics of NanoElectronics","","",""
"uuid:792cb42b-9122-464f-bc0a-0128a483890e","http://resolver.tudelft.nl/uuid:792cb42b-9122-464f-bc0a-0128a483890e","A Call for Value Literacy in Port City Transitions","Hein, C.M. (TU Delft History, Form & Aesthetics); Mulder, I. (TU Delft Design Conceptualization and Communication); Sennema, Hilde (Erasmus Universiteit Rotterdam)","","2021","Over the last decades, values have been re-addressed in planning, policies, businesses, heritage and education. While these fields seem to agree on the importance of values, it is often unclear what actors mean by values, and how they use these values to shape decisions. A decade after a global financial crisis, in the midst of a global pandemic, and on the eve of global climate emergencies, difficult choices need to be made to safeguard a sustainable future. These choices call for value-driven deliberations, especially in the globally connected, multi-problem environment of the port city. To do that, however, stakeholders need to know what they mean when they talk about values, and how to deliberate them. In other words: they need to be value literate. In this article, we study the concept of value and values in the context of port cities in the past, present and future. After an analysis of historical uses of values in port cities, we assess six projects that explicitly and implicitly deal with values in port cities, to explore methods or strategies that can help to elicit values in different phases of decision making processes.","Value Literacy; Methodology; Transitions; Port City Eco-system; Complexity","en","journal article","","","","","","Vol. 4 No. 2 (2021): Port City Cultures, Values, or Maritime Mindsets, Part 2: Studying and Shaping Cultures in Port City Territories","","","","","History, Form & Aesthetics","","",""
"uuid:1e13344e-0d89-45a9-ab33-ec773ccf8e0e","http://resolver.tudelft.nl/uuid:1e13344e-0d89-45a9-ab33-ec773ccf8e0e","Effects of Helicopter Dynamics on Autorotation Transfer of Training","Scaramuzzino, Paolo Francesco (TU Delft Control & Simulation; Politecnico di Milano); Pavel, M.D. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); Quaranta, Giuseppe (Politecnico di Milano)","","2021","This paper analyzes the effects of the helicopter dynamics on pilots’ learning process and transfer of learned skills during autorotation training. A quasi-transfer-of-training experiment was performed with 14 experienced helicopter pilots in a moving-base flight simulator. Two types of helicopter dynamics, characterized by a different autorotative index, were considered: “hard,” with high pilot compensation required, and “easy,” with low compensation required. Two groups of pilots tested the two types of dynamics in a different training sequence: hard-easy-hard (HEH group) and easy-hard-easy (EHE group). Participants of both groups were able to attain adequate performance at touchdown in most of the landings with both types of dynamics. However, a clear positive transfer effect in terms of acquired skills is found in both groups from the hard to the easy dynamics, but not from the easy to the hard dynamics, confirming previous experimental evidence. Positive transfer is especially observed for the rate of descent at touchdown. The two groups differed in the control strategy applied, with the HEH group having developed a more robust control technique. During the last training phase the EHE group aligned its control strategy with that of the HEH group.","","en","journal article","","","","","","","","2022-09-01","","","Control & Simulation","","",""
"uuid:c432edaa-b9ed-4702-9606-38f28a2a0234","http://resolver.tudelft.nl/uuid:c432edaa-b9ed-4702-9606-38f28a2a0234","Eigenmode Distortion: A New Perspective on Motion Cueing Fidelity in Flight Simulation","Miletović, I. (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); Wentink, Mark (Desdemona B.V.)","","2021","Eigenmode distortion is a novel quantitative methodology developed to objectively evaluate motion cueing fidelity in flight simulation. It relies on an explicit coupling of linearized vehicle and Motion Cueing Algorithm dynamics. Modal analysis subsequently performed on this coupled system reveals the degree of distortion imposed by the Motion Cueing Algorithm on to the dynamics of the simulated vehicle. Eigenmode distortion thereby provides unprecedented insight into the combined dynamics of the two systems along modal coordinates. Compared with existing methods for motion cueing fidelity assessment, the eigenmode distortion method enables a systematic analysis of the coupled vehicle and Motion Cueing Algorithm dynamics. This is mainly because it does not consider the Motion Cueing Algorithm in isolation and does not inherently rely on assumptions regarding the excitation of the simulated vehicle dynamics. This paper outlines the theoretical foundation of the eigenmode distortion method and includes a case study on helicopter longitudinal dynamics and a sensitivity analysis to demonstrate its utility. The results presented in this paper shown that the eigenmode distortion method can reveal interactions between the Motion Cueing Algorithm and the vehicle dynamics that are currently not captured by other established methods, such as the Sinacori–Schroeder criteria and the Objective Motion Cueing Test.","","en","journal article","","","","","","Accepted Author Manuscript","","","","","Control & Simulation","","",""
"uuid:93b19fe8-98c7-4017-a6b2-632833622f0b","http://resolver.tudelft.nl/uuid:93b19fe8-98c7-4017-a6b2-632833622f0b","Non-alloy Mg anode for Ni-MH batteries: Multiple approaches towards a stable cycling performance","Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2021","Mg attracts much research interest as anode material for Ni-MH batteries thanks to its lightweight, cost-effectiveness and high theoretical capacity (2200 mA h g−1). However, its practical application is tremendously challenged by the poor hydrogen sorption kinetics, passivation from aggressive aqueous electrolytes, and insulating nature of MgH2. Mg-based alloys exhibit enhanced hydrogen sorption kinetics and electrical conductivity, but significant amount of costly transition metal elements are required. In this work, we have, for the first time, utilized non-alloyed but catalyzed Mg as anode for Ni-MH batteries. 5 mol.% TiF3 was added to nanosized Mg for accelerating the hydrogen sorption kinetics. Several strategies for preventing the problematic passivation of Mg have been studied, including protective encapsulation of the electrode and utilizing room-temperature/high-temperature ionic liquids and an alkaline polymer membrane as working electrolyte. Promising electrochemical performance has been achieved in this Mg–TiF3 composite anode based Ni-MH batteries with room for further improvements.","Alkaline polymer membrane; Electrochemical hydrogen storage; Encapsulation; Ionic liquid; MgH; Ni-MH batteries","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:265b6610-1a93-4f1f-bf2c-3ffbb2c860b5","http://resolver.tudelft.nl/uuid:265b6610-1a93-4f1f-bf2c-3ffbb2c860b5","Exploring Multiple Perspectives in Citizenship Education with a Serious Game","Blokland, Erik (Student TU Delft); Cullinan, Caroline (Student TU Delft); Mulder, Doreen (Student TU Delft); Overman, Willie (Student TU Delft); Visscher, Marin (Student TU Delft); Zaidi, Amir (Student TU Delft); Bueno Perez, M.R. (TU Delft Computer Graphics and Visualisation); Bidarra, Rafael (TU Delft Computer Graphics and Visualisation)","Mitchell, Alex (editor); Vosmeer, Mirjam (editor)","2021","Within citizenship education, a new focus is being laid upon what is expected of citizens within a diverse and lightning-fast society: more emphasis is placed on teaching students how to understand and respect other people’s opinions, regardless of how they may contrast with one’s own. However, learning to be tolerant with others’ viewpoints comes with hurdles, as currently it is quite easy to become stuck within one’s own worldview. We developed Diermocratie, an in-classroom game aimed at encouraging a more open conversation, which breaks through these hurdles and addresses key competencies such as empathy and argumentation. By role-playing metaphors that parallel real-world events, students explore their own predispositions, are made aware of the perspectives of others, and are enabled to discuss issues objectively. From a preliminary evaluation, most students could identify the parallelism between the in-game metaphor and real-world situations. They also indicated that the game motivates them to further talk to each other, approaching sensitive topics among them.","Citizenship education; Diversity; Multiple perspectives; Serious games","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-06-06","","","Computer Graphics and Visualisation","","",""
"uuid:041dfe87-b5c4-4708-8bb8-228407dfa2a7","http://resolver.tudelft.nl/uuid:041dfe87-b5c4-4708-8bb8-228407dfa2a7","Human Threshold Model for Perceiving Changes in System Dynamics","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","Limitations of a haptic device can cause distortions of the force feedback it presents. Just-noticeable difference (JND) in system dynamics is important for creating transparent haptic interaction. Based on the previous work, this article presents a unified model that extends the existing JND rule. Our approach projects the JNDs in the mechanical properties of a second-order mass-spring-damper system onto the real and imaginary components of the system's frequency response function (FRF). We discuss the results of two experiments and show that the JNDs obtained for both the real and imaginary components can be expressed as the same fraction of, and thus are proportional to, the magnitude of the total system's FRF. Furthermore, the findings are generalized to cases where the system's dynamics order is different than two. What results is a unified model that accurately describes the threshold for changes in human perception of any linear system dynamics with only two dimensions: the real and imaginary axes in the complex plane.","Damping; Difference threshold; Force; Frequency response; frequency response function (FRF); Haptic interfaces; haptics; just-noticeable difference (JND); Manipulators; mass-spring-damper systems; System dynamics; Weber's law; Weber's law","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:2527ba1e-661c-4408-86c8-3a5aa6d1f893","http://resolver.tudelft.nl/uuid:2527ba1e-661c-4408-86c8-3a5aa6d1f893","A singular values approach in helicopter gas turbine engines flight testing analysis","Arush, I. (TU Delft Control & Simulation; National Test Pilot School); Pavel, M.D. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","The process of empirical models evaluation is at the core business of experimental flight-testing data analysis. Accurate and convenient flight-testing of helicopter engine(s) available power is crucial for predicting the total helicopter performance. Common practice in estimation of in-flight helicopter gas turbine engine power consists of a reduction of flight-test data into simplistic single-variable analysis approach. While such an approach is convenient for practical use, it often results in unrealistic predictions of the available engine(s) power. A novel approach for the helicopter available power problem is the so-called Multivariable Polynomial Optimization under Constraints method. In this method, 18 regressors, constructed from the engine non-dimensional parameters, are used to define empirical polynomial models. This paper is intended to complement the Multivariable Polynomial Optimization under Constraints method and answer the question of which multivariable polynomial can be generally used in representing helicopter gas-turbine engine performance? In this sense, a variety of seven gas-turbine engines installed on different helicopters are analyzed, each one giving 512 possible polynomial models to be used for available-power calculations. While conventional statistical methods of hypothesis-testing failed in providing the answer to the question stated above of which the best general empirical model for representing engine performance is, an alternative approach based on the Singular-Value-Decomposition theorem, was proven successful in providing the answer. Moreover, this approach presented in the paper yielded a short list of 10 simple and convenient multivariable polynomials, best representing the performance of all seven engines analyzed as a group.","flight-testing; Gas-turbine; helicopter-performance; Singular-Value-Decomposition","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:c515f001-50d9-4b15-9ce5-1c28fb3cf456","http://resolver.tudelft.nl/uuid:c515f001-50d9-4b15-9ce5-1c28fb3cf456","Port cities as hubs of diversity and inclusivity: The case of Rotterdam","Hein, C.M. (TU Delft History, Form & Aesthetics); Van de Laar, Paul; Jansen, Maurice; Luning, Sabine; Brandellero, Amanda; Azman, Lucija; Hinman, Sarah; Mulder, I. (TU Delft Design Conceptualization and Communication); Harteveld, Maurice (TU Delft Urban Design)","","2020","Port cities are a particular type of territory and are often long-standing examples of resilience, bringing opportunities, wealth, and innovation to their nations and their citizens. They have developed at the crossroads of international trade and commerce and the intersection of sea and land. Flows of people through trade and migration have played a key role in their spatial, social and cultural development. Their strong local identities share legacies of diversity and cosmopolitanism, but also of colonialism and segregation. The Qingjing Mosque in Quanzhou, Fujian speaks of the exchange between Arabia and China along the maritime silk road. Hanseatic cities stand as an example of far-flung networks with districts for foreign traders—think of the German merchants who established Bryggen, the German dock, in Bergen, now a UNESCO world heritage site.","","en","report","Port City Futures","","","","","","","","","","History, Form & Aesthetics","","",""
"uuid:97c30818-591b-4ca3-a198-fd95f173d6ce","http://resolver.tudelft.nl/uuid:97c30818-591b-4ca3-a198-fd95f173d6ce","Effects of Target Trajectory Bandwidth on Manual Control Behavior in Pursuit and Preview Tracking","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","The 1960s crossover model is widely applied to quantitatively predict a human controller's (HC's) manual control behavior. Unfortunately, the theory captures only compensatory tracking behavior and, as such, a limited range of real-world manual control tasks. This article finalizes recent advances in manual control theory toward more general pursuit and preview tracking tasks. It is quantified how HCs adapt their control behavior to a final crucial task variable: the target trajectory bandwidth. Beneficial adaptation strategies are first explored offline with computer simulations, using an extended crossover model theory for pursuit and preview tracking. The predictions are then verified with data from a human-in-the-loop experiment, in which participants tracked a target trajectory with bandwidths of 1.5, 2.5, and 4 rad/s, using compensatory, as well as pursuit and preview displays. In stark contrast to the crossover regression found in compensatory tasks, humans attenuate only their feedforward response when tracking higher-bandwidth trajectories in pursuit tasks, while their behavior is generally invariant in preview tasks. A full quantitative theory is now available to predict HC manual control behavior in tracking tasks, which includes HC adaptation to all key task variables.","Manual control; modeling; preview; pursuit; target trajectory bandwidth","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:43b0e75e-5af4-4d13-972d-8aa14071e537","http://resolver.tudelft.nl/uuid:43b0e75e-5af4-4d13-972d-8aa14071e537","Expectation Causes Misperception of the Attitude Indicator in Nonpilots: A Fixed-Base Simulator Experiment","Landman, H.M. (TU Delft Control & Simulation; TNO); Groen, Eric L. (TNO); van Paassen, M.M. (TU Delft Control & Simulation); Bronkhorst, Adelbert W. (TNO); Mulder, Max (TU Delft Control & Simulation)","","2020","Previous studies show that pilots sometimes make roll reversal errors (RREs) when responding to the aircraft bank angle shown on the attitude indicator (AI). This is suggestive of a perceptual ambiguity in the AI. In the current study, we investigated whether expectation contributes to such misperception. Twenty nonpilots performed tasks in a fixed-base flight simulator. Their expectation about the bank angle was manipulated with a flying task using outside view only. When flying at a bank angle, the outside view disappeared, a moving-horizon type AI was shown, and participants had to roll the wings level, trusting the AI. The AI often matched the previously flown turn. However, in some runs, it showed an opposite bank direction (Opposite condition), which was hypothesized to facilitate a misperception. In some other runs, it showed level flight (Level condition), which should not facilitate this. In a second session, participants rolled wings level without preceding flying task (Baseline condition). Participants made 11.2 times more RREs in the Opposite condition (75% error rate) compared to Baseline condition (6.7%), and 2.5 times more compared to the Level condition (30%). This indicates that RREs were in many cases caused by expectation-induced misperception of the AI bank angle.","frames of reference; perceptual organization; rivalry/bistability; spatial cognition; bistability; rivalry","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:c352f5d1-2e3f-4910-ba3c-57d471dee261","http://resolver.tudelft.nl/uuid:c352f5d1-2e3f-4910-ba3c-57d471dee261","UAV Haptic Interface for Dynamic Obstacle Avoidance","Piessens, Tom (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","Teleoperation by definition means a deprivation of the teleoperator's senses, which can pose a handicap when operating, e.g., an UAV, in an unknown, perhaps even dynamic environment. Noticing moving obstacles in such a situation can prove to be quite difficult and the UAV runs the risk of colliding with them. Previous work designed a shared control haptic interface based on the artificial force field method to help navigating in a static environment. This interface was evaluated for its usability in a dynamic environment where linearly moving obstacles were present. Offline simulations show that the existing interface would have difficulty in preventing collisions with moving obstacles. A new method is developed based on the velocity obstacles method. The new design supports the operator by using the haptic side stick to guide the operator out of a so-called ``forbidden velocity zone''. Offline tests show that the developed algorithm is indeed capable of avoiding both static and dynamic obstacles. It was implemented in a real-time simulator and investigated further with human-in-the-loop experiments. An initial test in a simulator with five participants shows promising results in avoiding sudden appearing obstacles and moving obstacles in the open field. The haptic controller, however makes maneuvering in tight spaces hard for the operator.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:5e6f741c-6ffd-49a8-b35a-fc97919b7706","http://resolver.tudelft.nl/uuid:5e6f741c-6ffd-49a8-b35a-fc97919b7706","Reconstruction of Pilot Behaviour from Cockpit Image Recorder","Tsuda, Hiroka (Japan Aerospace Exploration Agency); Stroosma, O. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","A method to automatically identify pilot actions from cockpit camera footage is reported in this paper. Although they have long been considered for the enhancement of flight safety, cockpit image recorders have not yet been standard equipment in aircraft cockpits. The rules on Flight Data Recorders have been changed, however, to include a cockpit image recorder as one of the safety devices, and it is recommended to be installed in small aircraft as a substitute for a Flight Data Recorder. With cockpit images becoming available, it would surely be useful for accident analysis as well as for daily flight analysis. Especially for the latter purpose, pilot behavior should be automatically analyzed and classified into specific actions, or procedures. The authors conducted a study to assess the feasibility of automatic detection of pilot actions in the cockpit by a machine learning process. Results show that even with a small amount of training data, the resulting algorithm could identify some typical actions, such as manipulation of the switches on the glare shield, with 80% accuracy. Even in cases with a button and a switch positioned very close to each other, the actions ‘pushing the switch’ and ‘pushing the button’ could be distinguished by the algorithm. The action estimation accuracy improves up to 90% when using the training data focused on the pilot’s body parts, rather than the data focused on the whole body.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Invited paper","","","","","Control & Simulation","","",""
"uuid:0d8056fb-dd49-43ef-9411-08a223bc1491","http://resolver.tudelft.nl/uuid:0d8056fb-dd49-43ef-9411-08a223bc1491","Effects of Grid Cell Size in Altitude Control in an Augmented Reality Terrain Display","da Silva Rosa, David (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Ernst, Johanne (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","Helicopter pilot performance in degraded visual conditions may be improved through sensor fusion and an augmented reality display. A simulator experiment with 12 participants was done to test the effect of synthetic terrain grid cell size and helicopter heave dynamics on task performance and control behaviour in a terrain-following hill-climb task. An increase in grid cell size lowered task performance and increased control activity due to reduced optical information. Slower heave dynamics decreased task performance and led to a more prospective control strategy. It was concluded that an effective AR terrain display for altitude control can be designed independently from the vehicle dynamics.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:7a47b7a0-f2d5-40d8-ae66-731a06a5d8a7","http://resolver.tudelft.nl/uuid:7a47b7a0-f2d5-40d8-ae66-731a06a5d8a7","Design and Evaluation of a Constraint-Based Head-Up Display for Helicopter Obstacle Avoidance During Forward Flight","Friesen, D. (TU Delft Control & Simulation; Politecnico di Milano); Pavel, M.D. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Masarati, Pierangelo (Politecnico di Milano); Mulder, Max (TU Delft Control & Simulation)","","2020","This paper aims to reveal the effect of different display design principles in the helicopter domain. Two different obstacle avoidance support displays are evaluated during low-altitude, forward helicopter flight: a baseline Head-Up Display (HUD) is complemented either by a conventional advisory display, or a constraint-based display inspired by Ecological Interface Design. The latter has only been sparsely applied in the helicopter domain. It is hypothesized that the advisory display reduces workload, increases situation awareness, and improves performance measures in nominal obstacle avoidance situations, while the constraint-based display increases the resilience of the pilot-vehicle system towards unexpected, off-nominal situations. Twelve helicopter pilots with varying flight experience participated in an experiment in the SIMONA Research Simulator at Delft University of Technology. Contrary to expectations, the experiment revealed no significant effects of the displays on any of the dependent measures. However, there was a trend of decreasing pilot workload and increasing situation awareness when employing any of the support displays, compared to the baseline HUD. Pilots preferred the advisory display in nominal and the constraint-based display in off-nominal situations, reproducing similar findings from research in the fixed-wing domain. The relatively short time-frame and monotony of the control-task, an already cue-rich baseline HUD condition, and similarity between the displays possibly prohibited revealing larger differences between conditions. Future research will analyze the obstacle avoidance trajectories of this experiment, possibly revealing changes in control strategy caused by the displays, even when the lumped performance measures are similar. A follow-up experiment will focus on a longer task time-frame, more variable situations, and a truly ecological display to investigate the effect of applying Ecological Interface Design and different automation systems in the helicopter domain.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","Invited paper","","","","","Control & Simulation","","",""
"uuid:ef45b0f7-ef93-4473-83e6-9b5c6aa30a41","http://resolver.tudelft.nl/uuid:ef45b0f7-ef93-4473-83e6-9b5c6aa30a41","Manual Control Behavior in Stereoscopic Vision-Enhanced Depth Control Tasks","Kemna, Maarten (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); Wentink, Mark (Desdemona B.V.); Mulder, Max (TU Delft Control & Simulation)","","2020","Numerous critical manual teleoperation tasks, such the control of the refueling boom during aerial refueling, require human controllers to accurately manipulate objects in the depth dimension, i.e., aligned with the viewing direction. To better understand the intricacies of depth control tasks and to be able to better support human controllers in such tasks, a cybernetic analysis of human control behavior in stereoscopic vision-enhanced depth control tasks would be a valuable extension of the current state-of-the-art in manual control research. This paper presents the initial findings of a human-in-the-loop experiment in which participants performed an abstract pursuit tracking task in which multisine target and disturbance forcing functions were used to facilitate cybernetic analysis of the measured control behavior. In terms of depth perception (i.e., perspective, viewing distance), the task was modeled after an aerial refueling scenario. Participants performed the pursuit tracking task for a reference ""flat-plane"" condition (task axis aligned with vertical screen axis) and depth tracking tasks either without stereoscopic cues, with natural stereoscopic vision, and with amplified hyperstereoscopic vision. Overall, the results of the experiment showed that participants achieved degraded task performance and less effective control dynamics in depth tracking tasks compared the the reference ""flat-plane"" condition. However, in line with earlier research on aerial refueling operator support systems, increased strength of the stereoscopic vision enhancements is found to enable much improved performance and increased human control gains.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:cfbfd0af-ab9a-4eec-9f67-3dc4e2c01dbb","http://resolver.tudelft.nl/uuid:cfbfd0af-ab9a-4eec-9f67-3dc4e2c01dbb","Design and Evaluation of Vertical Situation Display Reflecting Configuration Changes","van Geel, Alexander (Student TU Delft); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","Loss of control is the largest contributor to the yearly aviation death toll, with energy mismanagement in low-energy conditions as one of its main causal factors. This has led to a large emphasis from both scientific and aviation safety communities on the prevention of aircraft upset conditions. Changes in aircraft configuration largely impact performance, and improved insight therein should allow pilots to better predict potentially dangerous situations, maintain suitable safety margins and more effectively react to unforeseen events. This paper presents the design and experimental evaluation of a Vertical Situation Display (VSD) with enhancements visualizing changes in the flight performance envelope. Sixteen pilots were tasked to fly approach and go-around scenarios with both a baseline and an ecological VSD, some of the scenarios containing flight control failures. Results show that the new display makes pilots maintain larger margins in velocity, thus spending less time below the advised minimum speed limit in final approach. However, these larger velocity margins also led to larger errors with respect to target velocities. Flight control failures were more often and more quickly discovered, and pilots reported feeling better able to predict dangerous situations. No significant differences in workload were recorded. These results conclude that the new VSD design enhances safety performance, but simultaneously raise the question whether the effect of enlarged safety margins is desirable if it causes a reduction in velocity tracking.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:9785aaa4-20b9-4dda-b3ab-c8ed8caabfc7","http://resolver.tudelft.nl/uuid:9785aaa4-20b9-4dda-b3ab-c8ed8caabfc7","Using asymmetric vibrations for feedback on flight envelope protection","van Baelen, D. (TU Delft Control & Simulation); Ellerbroek, Joost (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Human-Robot Interaction); Mulder, Max (TU Delft Control & Simulation)","","2020","Modern aircraft use a variety of fly-by-wire control devices and combine these with a flight envelope protection system to limit pilot control inputs when approaching the aircraft limits. The current research project aims to increase pilot awareness of such a protection system through the use of force feedback on the control device, i.e., haptics. This paper describes a new iteration of a design with the specific aim to warn the pilot when approaching a limit and provide a clear direction of suggested control input. This is achieved by using vibrations asymmetric in both amplitude, i.e. the mean of the signal is non-zero, and time, i.e. a cue which has a rise time different from the fall time. An evaluation is performed where 24 active PPL/LAPL pilots flew a challenging vertical profile and encountered a windshear. The pilots are divided in two groups: one group performing four flights with haptic feedback, followed by four without, the other groups has a reversed order. Although acceptance ratings slightly improved when providing haptic feedback, the other metrics are unchanged when switching between haptic feedback conditions, due to a large training effect during the first four runs. The results do show that enabling the haptic feedback does seem to improve the learning rate over the first runs, and no after effects are present when feedback is removed. As such, next to the fact that most pilots indicated that they expect an improved safety, this experiment shows a potential training benefit of haptic feedback.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:6922c885-08ed-4aec-8029-a6d75b6f5da2","http://resolver.tudelft.nl/uuid:6922c885-08ed-4aec-8029-a6d75b6f5da2","Supplementing Haptic Feedback Through the Visual Display of Flight Envelope Boundaries","de Rooij, G. (TU Delft Control & Simulation); van Baelen, D. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","This paper describes the design and evaluation of a visual display in supplementing haptic feedback on the side stick as a way to communicate flight envelope boundaries to pilots. The design adds indications for the limits in airspeed, load factor, angle of attack and angle of bank to a standard Airbus primary flight display (PFD). The indications not only show the limits of the flight envelope, but also indicate magnitude and direction of the haptic cues. Fifteen professional Airbus pilots and one Airbus sim instructor participated in an experiment in the SIMONA Research Simulator at Delft University of Technology. Several approaches in three different scenarios were flown in alternate law with the old and new PFD, while haptic feedback was always enabled. Objective results do not show clear improvements with the new display, although the time spent outside the flight envelope is slightly reduced. Subjective results indicate a preference, however, for the new display and an increased understanding of the haptic feedback. Further research is recommended to focus on improving the design by removing unused indications and setting up an experiment with a bank scenario that allows the use of operational bank limits rather than artificially reduced limits.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:3c234f59-1748-4664-958f-674cb0c6762e","http://resolver.tudelft.nl/uuid:3c234f59-1748-4664-958f-674cb0c6762e","Design of a Haptic Feedback System for Flight Envelope Protection","van Baelen, D. (TU Delft Control & Simulation); Ellerbroek, Joost (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2020","Several modern aircraft use a passive control manipulator: a spring–damper system that generates command signals to the flight control computers in combination with a flight envelope protection system that limits pilot inputs when approaching the aircraft limits. This research project aims to increase pilot awareness of this protection system through the use of force feedback on the control device, that is, haptics. This paper describes in detail how the haptic feedback works and when it triggers; another paper will discuss the results of an experimental evaluation. With the current haptic design, pilots can get five cues: first, a discrete force cue when approaching the limits; second, an increased spring coefficient for control deflections that bring the aircraft closer to its limits; third, a stick shaker for low velocities; fourth, if a low-velocity condition requires an input, the stick is moved forward to the desired control input; and finally, the stick follows the automatic Airbus “pitch-up” command during an overspeed condition. This novel system is expected to help pilots correctly assess the situation and decide upon the right control action. It will be evaluated in two scenarios close to the flight envelope limits: a windshear and an icing event.","","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:c55fe748-af92-4876-b451-dd441333a20e","http://resolver.tudelft.nl/uuid:c55fe748-af92-4876-b451-dd441333a20e","The Effectiveness of a Mnemonic-Type Startle and Surprise Management Procedure for Pilots","Landman, H.M. (TU Delft Control & Simulation; TNO); van Middelaar, Sophie H. (Student TU Delft); Groen, Eric L. (TNO); van Paassen, M.M. (TU Delft Control & Simulation); Bronkhorst, Adelbert W. (TNO); Mulder, Max (TU Delft Control & Simulation)","","2020","Background: Mnemonic-type startle and surprise procedures were previously proposed to help pilots cope with startle and surprise in-flight, but effects on performance after procedure execution have not yet been investigated. Objective: Thus, we tested the effectiveness a new mnemonic-type procedure in a moving-base simulator with a non-linear model of a small twin-propeller aircraft flown single-pilot. Method: An experimental group of twelve line pilots was trained to use a four-item procedure: 1. Calm down: take a deep breath, sit up straight and relax shoulders and hands. 2. Observe: call out the basic flight parameters. 3. Outline: formulate a hypothesis about the problem. 4. Lead: formulate and execute a plan of action. A control group of twelve line pilots received a control training. Next, all pilots performed four scenarios with startling and surprising events. Data were obtained on pilot performance, stress, procedure application and evaluation. Results: Application of the procedure in the test scenarios was high (90.0% full, 100.0% partly), and pilots evaluated the procedure positively (median: 4 on a 1–5 point scale). There was significantly superior decision-making in the experimental group, but immediate responses were significantly less optimal. Pilots sometimes applied the procedure at inappropriate moments. Conclusion: The results of the tested mnemonic-type procedure were promising. The procedure may benefit, however, from modifications to reduce complexity and to stimulate application at the appropriate moment.","","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:a648077b-39ce-45b6-a04e-76a485fda9b8","http://resolver.tudelft.nl/uuid:a648077b-39ce-45b6-a04e-76a485fda9b8","A Variable Stability In-Flight Simulation System using Incremental Non-Linear Dynamic Inversion","Scholten, Pepijn (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","A variable stability in-flight simulator has the capabilities to change the response of an aircraft in-flight, often without changing the physical properties of the aircraft. The ability to adjust the aircraft response characteristics and handling qualities has various purposes, such as pilot training, control logic development and handling quality research. A variable stability control system is designed for a medium range business jet using Incremental Non-linear Dynamic Inversion. The performance of the in-flight simulator is verified by two experiments, one conducted in a fixed-base flight simulator and one in a Cessna Citation II laboratory aircraft. The fly-by-wire actuation system in the Cessna Citation II is based on its existing autopilot, inheriting the limited performance and safety protections.The simulator experiment shows differences between the experienced handling qualities for a reference model and the designed controller combined with aircraft dynamics. These differences mainly arise due to actuator saturation for specific handling quality settings. The in-flight experiment supports the simulator findings but also reveals how the available control authority around the initial condition is limited due to constraints of the fly-by-wire system.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:9e1dee7a-5719-4554-bf5d-f7ab9938c52c","http://resolver.tudelft.nl/uuid:9e1dee7a-5719-4554-bf5d-f7ab9938c52c","Research Note: A workaround for the corner problem in numerically exact non-reflecting boundary conditions","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2020","Simulations of wave propagation in the Earth usually require truncation of a larger domain to the region of interest to keep computational cost acceptable. This introduces artificial boundaries that should not generate reflected waves. Most existing boundary conditions are not able to completely suppress all the reflected energy, but suffice in practice except when modelling subtle events such as interbed multiples. Exact boundary conditions promise better performance but are usually formulated in terms of the governing wave equation and, after discretization, still may produce unwanted artefacts. Numerically exact non-reflecting boundary conditions are instead formulated in terms of the discretized wave equation. They have the property that the numerical solution computed on a given domain is the same as one on a domain enlarged to the extent that waves reflected from the boundary do not have the time to reach the original truncated domain. With a second- or higher-order finite-difference scheme for the one-dimensional wave equation, these boundary conditions follow from a recurrence relation. In its generalization to two or three dimensions, a recurrence relation was only found for a single non-reflecting boundary on one side of the domain or two of them at opposing ends. The other boundaries should then be zero Dirichlet or Neumann. If two non-reflecting boundaries meet at a corner, translation invariance is lost and a simple recurrence relation could not be found. Here, a workaround is presented that restores translation invariance by imposing classic, approximately non-reflecting boundary conditions on the other sides and numerically exact ones on the two opposing sides that otherwise would create the strongest reflected waves with the classic condition. The exact ones can also be applied independently. As a proof of principle, the method is applied to the two-dimensional acoustic wave equation, discretized on a rectangular domain with a second-order finite-difference scheme and first-order Enquist–Majda boundary conditions as approximate ones. The method is computationally costly but has the advantage that it can be reused on a sequence of problems as long as the time step and the sound speed values next to the boundary are kept fixed.","Acoustics; Computing aspects; Mathematical formulation; Modelling; Seismics","en","journal article","","","","","","Accepted Author Manuscript","","2021-07-29","","","Applied Geophysics and Petrophysics","","",""
"uuid:68583842-8b9f-45ae-9cc6-2e79d56ccde3","http://resolver.tudelft.nl/uuid:68583842-8b9f-45ae-9cc6-2e79d56ccde3","Revenue management with two fare classes in synchromodal container transportation","Van Riessen, Bart (Erasmus Universiteit Rotterdam); Mulder, Judith (Erasmus Universiteit Rotterdam); Negenborn, R.R. (TU Delft Transport Engineering and Logistics); Dekker, Rommert (Erasmus Universiteit Rotterdam)","","2020","The cargo fare class mix (CFCM) problem aims to find the optimal fare class mix for a given intermodal transportation network based on known client demands. It is based on a revenue management problem for aviation passengers, the fare class mix problem, but considering intermodal cargo transportation, two major differences apply. Firstly, the CFCM’s premise is that long-term commitments to customers must be provided, such that a customer has a guaranteed daily capacity. Secondly, cargo may be rescheduled or rerouted, as long as the customer’s delivery due date is met. Our goal is to balance revenue maximisation and capacity utilisation by optimally combining two delivery service levels. Therefore, the optimisation problem is to select fare class limits at a tactical level up to which transportation demand will be accepted on a daily basis at the operational level. Any accepted demand that does not fit on the available network capacity during operation, must be transported by truck at increased expenses for the network operator. In this paper, we propose a faster method than the previously proposed solution method for a single corridor network and we provide proofs for the optimality of the result. Using this, we extend the problem to an intermodal network of multiple corridors. We provide numerical results for different settings, in which we compare the baseline of individual corridor optimums with the result of using rerouting. Finally, we apply the methods in a case study for an intermodal transportation network in North-West Europe.","Container transportation; Fare class sizes; Intermodal planning; Revenue management; Synchromodal planning","en","journal article","","","","","","","","","","","Transport Engineering and Logistics","","",""
"uuid:bb5438bb-cc07-499f-9a09-96d64fd29996","http://resolver.tudelft.nl/uuid:bb5438bb-cc07-499f-9a09-96d64fd29996","Research Note: On the error behaviour of force and moment sources in simplicial spectral finite elements","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2020","The representation of a force or moment point source in a spectral finite-element code for modelling elastic wave propagation becomes fundamentally different in degenerate cases where the source is located on the boundary of an element. This difference is related to the fact that the finite-element basis functions are continuous across element boundaries, but their derivatives are not. A method is presented that effectively deals with this problem. Tests on one-dimensional elements show that the numerical errors for a force source follow the expected convergence rate in terms of the element size, apart from isolated cases where superconvergence occurs. For a moment source, the method also converges but one order of accuracy is lost, probably because of the reduced regularity of the problem. Numerical tests in three dimensions on continuous mass-lumped tetrahedral elements show a similar error behaviour as in the one-dimensional case, although in three dimensions the loss of accuracy for the moment source is not a severe as a full order.","Computing aspects; Elastics; Mathematical formulation; Modelling; Seismics","en","journal article","","","","","","Accepted Author Manuscript","","2021-07-18","","","Applied Geophysics and Petrophysics","","",""
"uuid:e4de61df-627c-4892-b667-09749846e03e","http://resolver.tudelft.nl/uuid:e4de61df-627c-4892-b667-09749846e03e","Variable stability in-flight simulation system based on existing autopilot hardware","Scholten, Pepijn A. (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Chu, Q. P. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","A variable stability in-flight simulator has the capabilities to change the response of an aircraft in-flight, often without changing the physical properties of the aircraft. The ability to adjust the aircraft response characteristics and handling qualities has various purposes, such as pilot training, control system development, and handling quality research. A variable stability control system is designed for a medium-range business jet using incremental nonlinear dynamic inversion. The performance of the in-flight simulator is verified by two experiments, one conducted in a fixed-base flight simulator and one in a Cessna Citation II laboratory aircraft. The fly-by-wire actuation system in the Cessna Citation II is based on its existing autopilot, inheriting the limited performance and safety protections. The simulator experiment shows differences between the experienced handling qualities for a reference model and the designed controller combined with aircraft dynamics. These differences mainly arise due to actuator saturation for specific handling quality settings. The in-flight experiment supports the simulator findings but also reveals how the available control authority around the initial condition is limited due to constraints of the fly-by-wire system.","","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:8db2656b-e37e-4999-ac9e-3ed3f7c0ad31","http://resolver.tudelft.nl/uuid:8db2656b-e37e-4999-ac9e-3ed3f7c0ad31","Considering the human-dimension to make sustainable transitions actionable","Reyes, María Elena L. (Student TU Delft); Zwagers, W.A. (Student TU Delft); Mulder, I. (TU Delft Design Conceptualization and Communication)","","2020","Sustainable innovation and transitions are increasingly gaining traction within academia, industries, and policymakers. Despite the research efforts, sustaining innovation and operationalizing transitions still remains a barely explored field. The pragmatic step from understanding towards doing is often not made explicit in the literature. In fact, it results in an unclear and vague grip on how to operationalize these understandings, or differently put on how to make this understanding pragmatic. In the current article, we conducted an integrative literature review using human-centeredness lenses that informs the so-called ‘Human-Dimension’ framework. We argue that adding the Human-Dimension to the existing models for analysis, such as the Multi-Level Perspective framework, might clarify the different meanings that emerge within the network of actors in a transition, and knowing how to translate those individual meanings towards a collective construction of meaning might be enabled. To illustrate the framework’s contribution, we applied it to the context of a local sustainable development project. The results show how human-centeredness could serve as a domain to make the Human-Dimension of sustainable transitions actionable.","Actionable; Human-centeredness; Human-dimension; Multi-level perspective; Sustainable innovation; Sustainable transitions","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:d2e7d329-44de-49ec-9ef7-901f17174f6d","http://resolver.tudelft.nl/uuid:d2e7d329-44de-49ec-9ef7-901f17174f6d","Insecure tenure in Amsterdam: who rents with a temporary lease, and why? A baseline from 2015","Huisman, C.J. (TU Delft Housing Management; Rijksuniversiteit Groningen); Mulder, Clara H. (Rijksuniversiteit Groningen)","","2020","Given that insecure leases impact negatively on ontological security and subjective well-being, and given increasing pressure on European housing markets, more insight into insecure leases is timely. In this article, we assess the occurrence of temporary leases in the city of Amsterdam in 2015, and explore the characteristics of the tenants. We employ hitherto underused local survey data (N = 17,803). Although permanent contracts are still dominant, the majority of young adults aged 18–23 are renters with a temporary lease. Students, those with a Western migration background, those who moved because their previous rental contract was terminated or because the previous dwelling was too expensive, and those who moved from abroad were particularly likely to have a temporary lease. Families were unlikely to have a temporary lease. Given recent developments–in 2016 temporary leases were legally established as a regular tenure in the Netherlands–the number of temporary leases may increase sharply from the reported baseline of 2015.","multinomial logistic regression; policy; rental housing; Security of tenure; temporary contracts; the Netherlands","en","journal article","","","","","","","","","","","Housing Management","","",""
"uuid:910e7327-5216-4e27-81d5-1eec59fbb3be","http://resolver.tudelft.nl/uuid:910e7327-5216-4e27-81d5-1eec59fbb3be","Status of National Open Spatial Data Infrastructures: a Comparison Across Continents","Mulder, A.E. (Student TU Delft); Wiersma, M.G. (Geonovum); van Loenen, B. (TU Delft Geo Information)","","2020","The increasing need for geospatial information demands for well-organised management among all levels of society. A Spatial Data Infrastructure (SDI) is a multidisciplinary and dynamic instrument that facilitates access and sharing of geospatial information. The current trend towards open data initiatives is influencing the development of these infrastructures. In order to examine this effect, this article addresses the following question: what is the current state of SDI openness of four best practice open data countries Canada, The Netherlands, Australia and Brazil, and how do they compare? The question is answered through a qualitative literature study and the application of a newly developed Open SDI Assessment Framework to the countries. The Netherlands and Canada show a high performance on all assessment dimensions; data discovery, data access and data properties. Australia and Brazil show a poor open SDI performance, as they could not meet the requirements set for the assessed datasets. General conclusions of the assessment are that data is currently fragmented and scattered among the web in all four countries, which strongly negatively influences the user experience. It is crucial that a strict legal framework is embedded in a country, which ensures that current SDI objectives and propositions regarding an user-centred approach and open data availability are achieved.","open data; spatial data infrastructure; assessment framework; open SDI; User-Centric; Argentina; Australia; Canada; Netherlands","en","journal article","","","","","","","","","","","Geo Information","","",""
"uuid:3aebdc1c-3ee7-43ea-ac7f-b8274934f7a1","http://resolver.tudelft.nl/uuid:3aebdc1c-3ee7-43ea-ac7f-b8274934f7a1","Urban dunes: promoting BwN dune formation at nourished beaches through spatial design","van Bergen, J. (TU Delft Landscape Architecture); Nijhuis, S. (TU Delft Landscape Architecture); Mulder, Jan (University of Twente); Wijnberg, Kathelijne (University of Twente)","","2020","","","en","abstract","","","","","","","","","","","Landscape Architecture","","",""
"uuid:65881f28-c36a-45ef-91c3-84ee25f66872","http://resolver.tudelft.nl/uuid:65881f28-c36a-45ef-91c3-84ee25f66872","Leans Illusion in Hexapod Simulator Facilitates Erroneous Responses to Artificial Horizon in Airline Pilots","van den Hoed, Annemarie (Student TU Delft); Landman, H.M. (TU Delft Control & Simulation; TNO); van Baelen, D. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Groen, Eric L. (TNO); Mulder, Max (TU Delft Control & Simulation)","","2020","Objective: We tested whether a procedure in a hexapod simulator can cause incorrect assumptions of the bank angle (i.e., the “leans”) in airline pilots as well as incorrect interpretations of the attitude indicator (AI). Background: The effect of the leans on interpretation errors has previously been demonstrated in nonpilots. In-flight, incorrect assumptions can arise due to misleading roll cues (spatial disorientation). Method: Pilots (n = 18) performed 36 runs, in which they were asked to roll to wings level using only the AI. They received roll cues before the AI was shown, which matched with the AI bank angle direction in most runs, but which were toward the opposite direction in a leans-opposite condition (four runs). In a baseline condition (four runs), they received no roll cues. To test whether pilots responded to the AI, the AI sometimes showed wings level following roll cues in a leans-level condition (four runs). Results: Overall, pilots made significantly more errors in the leans-opposite (19.4%) compared to the baseline (6.9%) or leans-level condition (0.0%). There was a pronounced learning effect in the leans-opposite condition, as 38.9% of pilots made an error in the first exposure to this condition. Experience (i.e., flight hours) had no significant effects. Conclusion: The leans procedure was effective in inducing AI misinterpretations and control input errors in pilots. Application: The procedure can be used in spatial disorientation demonstrations. The results underline the importance of unambiguous displays that should be able to quickly correct incorrect assumptions due to spatial disorientation.","aviation; display; perception; simulation; spatial disorientation","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:80a7f7c4-d940-49c1-995d-44d9544e6f93","http://resolver.tudelft.nl/uuid:80a7f7c4-d940-49c1-995d-44d9544e6f93","Unlocking the democratic potential of design capabilities in public management","Rita, F. (Student TU Delft); Mulder, I. (TU Delft Design Conceptualization and Communication); Calderon Gonzalez, A. (TU Delft Design Conceptualization and Communication)","","2020","Public management needs to keep pace with contemporary problems and harvest capabilities to meet future scenarios. Consequently, practitioners in the public field must advocate for critical discussions and engage with people who are going to benefit from their guidance. The purpose of the current research is to investigate strategies to
strengthen public management by exploring the potential of Design Thinking as a policy competency. A participatory design approach has been selected to co-create a learning environment for building design capabilities. In other words, a safe space that allows for sharing and nurturing knowledge, skills and attitudes. The setup of the participatory process entails a thorough exploration, in which a team of seven public managers of a regional association of municipalities participated. In four participatory sessions, a learning space has been iteratively prototyped, and finally evaluated in the context. Advantages and challenges to the selected approach are discussed to provide guidelines for a practical
application and replication of the process within the target domain. It can be concluded that design interventions developed with the current integrated design approach have demonstrated viable opportunities for capacity-building inpublic management.","Participatory design; Design Capabilities; Learning environment; Collaboration; Public management; Capacity building; Co-reflection","en","conference paper","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:0b8a608c-5270-4955-80c5-a8585cd897ae","http://resolver.tudelft.nl/uuid:0b8a608c-5270-4955-80c5-a8585cd897ae","Sensitivity Analysis of an MPC-based Motion Cueing Algorithm for a Curve Driving Scenario","van der Ploeg, J.R. (Student TU Delft; Max Planck Institute for Biological Cybernetics); Cleij, D. (TU Delft Control & Simulation; Max Planck Institute for Biological Cybernetics); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); Bülthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics)","","2020","Despite gaining popularity, the use of Motion Cueing Algorithms (MCAs) based on Model Predictive Control (MPC) remains challenging due to the required tuning of a large number of cost function parameters. This paper investigates the effects of two critical MPC cost function parameters, the lateral specific force and roll rate error weights (Way and Wp), on the motion cueing quality achieved with an MPC-based MCA for a curve driving scenario. An offline sensitivity analysis, which quantified the effects of varying Way and Wp on the Root Mean Square Error (RMSE) and Pearson Correlation Coefficient (PCC) of the resulting simulator motion outputs, shows that for the same percentage-wise variation, Way has a more pronounced effect on both cueing quality predictors than Wp. In addition, for both RMSE and PCC, the effects of Way and Wp are also found to be largely independent, i.e., without interaction effects. This was further tested in a passive human-in-the-loop experiment with 20 participants and with nine different Way and Wp parameter combinations as test conditions, performed in the hexapod moving-base simulator of the Max Planck Institute for Biological Cybernetics in T¨ubingen. The collected continuous rating data, which were found to be reliable for 18/20 participants, show a statistically significant variation across all experiment conditions, and especially a strong interaction effect of Way and Wp. Somewhat surprisingly, the overall lowest continuous ratings were given to the combination of both reference weight settings from earlier research (our baseline condition). In line with the interaction effect in the continuous data, an extended post-experiment correlation analysis shows that a weighted combination of lateral specific force RMSE and and roll rate RMSE above the roll rate perception threshold strongly correlates (_ = 0.98) with the variation in mean continuous ratings across all experiment conditions. This approach can potentially be used for straightforward prediction of perceived motion cueing quality and offline MCA optimization.","Motion cueing; driving simulators; model predictive control; curve driving; continuous subjective ratings","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:1317a9fa-d156-409f-9f08-edb3548430cb","http://resolver.tudelft.nl/uuid:1317a9fa-d156-409f-9f08-edb3548430cb","Comparison of Quality Metrics between Motion Cueing Algorithms in a Virtual Test Environment","Kolff, M.J.C. (TU Delft Control & Simulation; BMW Group); Venrooij, J. (BMW Group); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","Motion cueing algorithm design often involves a trade-off between priorities due to the limited workspace of the simulator. Such a trade-off requires a detailed understanding of human perception, which we do not yet have. For that reason, objective motion cueing quality metrics, based on the difference between vehicle and simulator signals, offer a fast and simple alternative. Next to motion cueing quality, we argue that the total motion cueing algorithm (MCA) quality is about more than only the quality of the motion, and can also entail implementation and operational aspects of an MCA for a specific use-case and simulator combination, i.e., it is a task-dependent issue. In this paper this idea is discussed by comparing three objective motion cueing quality metrics (absolute difference, delay and cross-correlation) from literature and two metrics regarding simulator operations (workspace management and energy consumption). Comparing such metrics is difficult, but is nevertheless useful to improve the process of simulator operations if various MCAs and/or simulators are available, to aid their selection pro- cess. As a first step towards such a method, a Virtual Test Environment (VTE) was developed as a versatile software environment to compare these metrics, as well as to visualize simulator motion and its characteristics in a 3D-animation. This aims at helping MCA designers in making choices between different MCA types, their configurations, simulators and use-cases, guiding them to select the best-suited motion cueing solution.","Motion cueing; quality comparison; objective criteria; test environment","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:0c34b1dd-2e36-4625-b767-a8c5063128d9","http://resolver.tudelft.nl/uuid:0c34b1dd-2e36-4625-b767-a8c5063128d9","Optimizing an Optimization-Based MCA using Perceived Motion Incongruence Models","Cleij, D. (TU Delft Control & Simulation; Max Planck Institute for Biological Cybernetics); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); Bülthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics)","","2020","In this paper the potential of Motion Incongruence Rating (MIR) models for the optimization of Motion Cueing Algorithms (MCAs) is investigated. In a human-in-the-loop simulator experiment, two optimization-based MCAs are compared for a roundabout scenario simulated on a medium-stroke hexapod simulator. The first MCA uses standard cueing error weights from reference literature in its cost function, while for the second case these weights were based on a MIR model fitted to previous experiment data. Results show that such models provide a promising cueing error weight estimation method for optimization-based MCAs, but also highlight the limitations of these models due to, for example, their dependency on the richness of the datasets to which they are fitted.","Motion cueing algorithms; motion incongruence models; model predictive control; continuous ratings","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:f090fecb-01b7-4060-bcaf-a262dc828994","http://resolver.tudelft.nl/uuid:f090fecb-01b7-4060-bcaf-a262dc828994","Simulator Sickness Ratings Reduce with Simulator Motion when Driven Through Urban Environments","Hogerbrug, M. (TU Delft Control & Simulation; BMW Group); Venrooij, J. (BMW Group); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2020","A necessity in driving simulation testing is to understand and attenuate simulator sickness, to reduce the number of undesired drop-outs. Especially urban environments, with its many turns and changes in the velocity profile, are a challenge. This paper describes the motion sickness rating results of a between-subjects experiment (n = 63), which investigated the effects of adding scaled yaw motion to a simulator on the sickness incidence and severity while being driven as passenger through an urban environment. Three cases were considered: no motion, scaled yaw motion, and including the vehicle pitch and roll rotations in addition to the scaled yaw motion. The misery scale (MISC) was obtained every minute, and the simulator sickness questionnaire (SSQ) was completed before and after the 45-minute trial. Experimental results show that less participants became sick when some form of yaw-motion was provided.","Motion cueing; Driving simulators; simulator sickness; simulator motion; subjective ratings","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:9a65a574-b6a2-4a61-822e-04e6924eb75a","http://resolver.tudelft.nl/uuid:9a65a574-b6a2-4a61-822e-04e6924eb75a","Modelling episodic induced seismicity with poroelastic dynamic rupture and large-scale wavefield propagation","Ruan, J. (TU Delft Applied Geophysics and Petrophysics); Ghose, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2020","Modelling dynamic rupture is essential to correctly describe the process of induced seismicity. Defmod, an open-source finite-element code featuring quasi-static loading, co-seismic volumetric strain, and dynamic rupture, is used to simulate the entire chain of induced seismicity, from pressure evolution due to fluid injection and extraction, building up of stress, and nucleation of dynamic faulting, to wavefield propagation towards the surface. To study induced earthquakes caused by fluid extraction, we modelled the behaviour of a 2-D poroelastic medium including a predefined fault by assigning a fluid source, either constant or varying, in a homogeneous reservoir layer to induce a pressure-field change. For each quasi-static step, the pressure field difference generates a displacement field that in turn affects the pressure through a coupling matrix, depending on Biot's coefficient. The rate of pressure variation is
subject to the fluid source as well as the material properties, e.g., porosity and fluid mobility, which affect the speed and distribution of the stress build-up on the fault and thus the pattern of rupture nucleation. In addition, we implemented a predefined pressure profile to simulate the induced rupture in case of a uniform depletion of the reservoir to allow for a comparison with other studies. The results
provide useful insights on the causality between reservoir-pressure behaviour and the induced seismicity.","induced earthquakes; finite element method; poroelasticity; dynamic rupture; Defmod","en","abstract","","","","","","Accepted Author Manuscript","","2021-02-26","","","Applied Geophysics and Petrophysics","","",""
"uuid:1d39f774-6007-422d-9f14-c4d18d932765","http://resolver.tudelft.nl/uuid:1d39f774-6007-422d-9f14-c4d18d932765","Biomimicry design thinking education: a base-line exercise in preconceptions of biological analogies","Stevens, L.L. (TU Delft Science Education and Communication; The Hague University of Applied Sciences); Kopnina, Helen (The Hague University of Applied Sciences); Mulder, K.F. (TU Delft Organisation & Governance; The Hague University of Applied Sciences); de Vries, M.J. (TU Delft Science Education and Communication; TU Delft Ethics & Philosophy of Technology)","","2020","Preliminary empirical research conducted by the leading author has shown that design students using biological analogies, or models across different contexts, often misinterpreted these, intentionally or unintentionally, during design. By copying shape or form without integrating the main function of the mimicked biological model, students failed to consider the process or system directing that function when attempting to solve the design need. This article considers the first step in the development of an applicable educational model using distant analogies from nature, by means of biomimicry thinking methodology. The analysis examines results from a base-line exercise taken by students in the Minor Design with Nature during the Spring semester of Industrial Design Engineering at The Hague University of Applied Sciences in 2019, verifying that students without biomimicry training use this hollow approach automatically. This research confirms the gap between where students are at the beginning of the semester and where they need to be as expert sustainable designers when they graduate. These findings provide a starting point for future interventions in biomimicry workshops to improve systematic design thinking through structural and scientifically based iterations of analogical reasoning.","Analogical reasoning; Biomimicry; Design thinking; Distant analogies; Sustainable design education","en","journal article","","","","","","","","","","","Science Education and Communication","","",""
"uuid:bdf6285f-0b26-4e23-804f-0c3a91a0e2a1","http://resolver.tudelft.nl/uuid:bdf6285f-0b26-4e23-804f-0c3a91a0e2a1","Developing Lattice Matched ZnMgSe Shells on InZnP Quantum Dots for Phosphor Applications","Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Kirkwood, N.R.M. (TU Delft ChemE/Opto-electronic Materials); De Trizio, Luca (Istituto Italiano di Tecnologia); Li, Chen (Universiteit Antwerpen); Bals, Sara (Universiteit Antwerpen); Manna, L. (Istituto Italiano di Tecnologia); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials)","","2020","Indium phosphide quantum dots (QDs) have drawn attention as alternatives to cadmium- and lead-based QDs that are currently used as phosphors in lamps and displays. The main drawbacks of InP QDs are, in general, a lower photoluminescence quantum yield (PLQY), a decreased color purity, and poor chemical stability. In this research, we attempted to increase the PLQY and stability of indium phosphide QDs by developing lattice matched InP/MgSe core-shell nanoheterostructures. The choice of MgSe comes from the fact that, in theory, it has a near-perfect lattice match with InP, provided MgSe is grown in the zinc blende crystal structure, which can be achieved by alloying with zinc. To retain lattice matching, we used Zn in both the core and shell and we fabricated InZnP/ZnxMg1-xSe core/shell QDs. To identify the most suitable conditions for the shell growth, we first developed a synthesis route to ZnxMg1-xSe nanocrystals (NCs) wherein Mg is effectively incorporated. Our optimized procedure was employed for the successful growth of ZnxMg1-xSe shells around In(Zn)P QDs. The corresponding core/shell systems exhibit PLQYs higher than those of the starting In(Zn)P QDs and, more importantly, a higher color purity upon increasing the Mg content. The results are discussed in the context of a reduced density of interface states upon using better lattice matched ZnxMg1-xSe shells.","core-shell; InP; lattice matching; MgSe; phosphor; quantum dots","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:a3344ee6-698e-4eb1-b486-e6d46089e725","http://resolver.tudelft.nl/uuid:a3344ee6-698e-4eb1-b486-e6d46089e725","Locating and Controlling the Zn Content in In(Zn)P Quantum Dots","Kirkwood, N.R.M. (TU Delft ChemE/Opto-electronic Materials); De Backer, Annick (Universiteit Antwerpen); Longo, Alessandro (Universiteit Gent; Instituto per lo Studio dei Materiali Nanostrutturati); Geuchies, J.J. (TU Delft ChemE/Opto-electronic Materials); Mulder, J.T. (TU Delft ChemE/Opto-electronic Materials); Renaud, N. (TU Delft ChemE/Opto-electronic Materials); Bals, Sara (Universiteit Antwerpen); Manna, L. (Istituto Italiano di Tecnologia); Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials)","","2020","Zinc is routinely employed in the synthesis of InP quantum dots (QDs) to improve the photoluminescence efficiency and carrier mobility of the resulting In(Zn)P alloy nanostructures. The exact location of Zn in the final structures and the mechanism by which it enhances the optoelectronic properties of the QDs are debated. We use synchrotron X-ray absorbance spectroscopy to show that the majority of Zn in In(Zn)P QDs is located at their surface as Zn carboxylates. However, a small amount of Zn is present inside the bulk of the QDs with the consequent contraction of their lattice, as confirmed by combining high-resolution high-angle annular dark-field imaging scanning transmission electron microscopy with statistical parameter estimation theory. We further demonstrate that the Zn content and its incorporation into the QDs can be tuned by the ligation of commonly employed Zn carboxylate precursors: the use of highly reactive Zn acetate leads to the formation of undesired Zn3P2 and the final nanostructures being characterized by broad optical features, whereas Zn carboxylates with longer carbon chains lead to InP crystals with much lower zinc content and narrow optical features. These results can explain the differences between structural and optical properties of In(Zn)P samples reported across the literature and provide a rational method to tune the amount of Zn in InP nanocrystals and to drive the incorporation of Zn either as surface Zn carboxylate, as a substitutional dopant inside the InP crystal lattice, or even predominantly as Zn3P2.","","en","journal article","","","","","","","","","","","ChemE/Opto-electronic Materials","","",""
"uuid:de49f144-9425-47d2-9629-253248ad1c94","http://resolver.tudelft.nl/uuid:de49f144-9425-47d2-9629-253248ad1c94","Gas Chromatographic Method for in Situ Ammonia Quantification at Parts per Billion Levels","Zaffaroni, R. (TU Delft ChemE/Materials for Energy Conversion and Storage); Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage); Middelkoop, J. (TU Delft ChemE/O&O groep); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2020","","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:8f7ac7d7-047f-4231-b2da-8575c0b61bf6","http://resolver.tudelft.nl/uuid:8f7ac7d7-047f-4231-b2da-8575c0b61bf6","The need for sustainable teleconsultation systems in the aftermath of the first COVID-19 Wave","Giunti, Guido (TU Delft Applied Ergonomics and Design; University of Oulu); Goossens, R.H.M. (TU Delft Applied Ergonomics and Design; TU Delft Human-Centered Design); de Bont, Antoinette (Erasmus Universiteit Rotterdam); Visser, J.J. (Erasmus MC); Mulder, Mark (Erasmus MC); Schuit, Stephanie C.E. (Erasmus MC)","","2020","The physical and social distancing measures that have been adopted worldwide because of COVID-19 will probably remain in place for a long time, especially for senior adults, people with chronic conditions, and other at-risk populations. Teleconsultations can be useful in ensuring that patients continue to receive clinical care while reducing physical crowding and avoiding unnecessary exposure of health care staff. Implementation processes that typically take months of planning, budgeting, pilot testing, and education were compressed into days. However, in the urgency to deal with the present crisis, we may be forgetting that the introduction of digital health is not exclusively a technological issue, but part of a complex organizational change problem. This viewpoint offers insight regarding issues that rapidly adopted teleconsultation systems may face in a post–COVID-19 world.","COVID-19; Digital health; Exposure; Organization; Software; Teleconsultation; Telehealth; Telemedicine; OA-Fund TU Delft","en","journal article","","","","","","","","","","Human-Centered Design","Applied Ergonomics and Design","","",""
"uuid:dbf2b485-124f-43ca-ad87-dd1ce05a5f9f","http://resolver.tudelft.nl/uuid:dbf2b485-124f-43ca-ad87-dd1ce05a5f9f","Developing a Design Inquiry Method for Data Exploration","Kun, P. (TU Delft Design Conceptualization and Communication; Aalborg University); Mulder, I. (TU Delft Design Conceptualization and Communication); Kortuem, G.W. (TU Delft Internet of Things)","","2020","The increasing availability of large-scale datasets such as sensor data or social media data and increasingly accessible data science tools create unique
opportunities for design. However, the relationship between data science practices and design methods is still underdeveloped. In this paper, we propose that data exploration activities can be effectively embedded within a broader design inquiry framework and define a new design method, coined Data Exploration for Design, to support methodical designerly data exploration. The design method addresses the novice’s learning curve and supporting developing a data exploration inquiry mindset with procedures and curated tools. The empirical evaluation highlights support for producing exploration outcomes that are worth the additional technical effort. We close the paper by positioning the
findings in design methodology literature and motivating data exploration principles for design inquiry. The principles urge to acknowledge biases in data collection, spending time with the data, using visualizations as a means-to-anend, and designers being part of the data collection","data exploration; design methods; digital design; technology","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:79581fb2-b445-4392-bee5-2758ac1575a4","http://resolver.tudelft.nl/uuid:79581fb2-b445-4392-bee5-2758ac1575a4","Exploring Short-Term Training Effects of Ecological Interfaces: A Case Study in Air Traffic Control","Borst, C. (TU Delft Control & Simulation); Visser, Roeland M. (Netherlands Airport Consultants, Den Haag); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","In many work domains, the push toward higher levels of automation raises the concern of diminishing human expertise. Ecological interfaces could help operators in retaining and potentially even in acquiring expertise as they are hypothesized to lead to a deeper understanding of the work domain. This study explores the short-term impact of ecological interfaces on knowledge development and compares the results with an instruction-based training method. To monitor and compare students' progress, their decision-making strategies, identified from verbal comments recorded in 'think-aloud' simulator sessions, are mapped onto the decision ladder. This method has been applied to an experiment (N=16) aimed at training novices in conflict detection and resolution (CD&R) within a simplified air traffic control context. Results show that the overall CD&R performance in the final measurement sessions, featuring a transfer manipulation, was not significantly different between the 'ecological' and 'instructional' groups. In terms of cognitive behavior, however, students in the ecological group exhibited more laborious rule- and knowledge-based behaviors that sparked goal-oriented thoughts and corresponding control performances beyond the CD&R task. These findings indicate that ecological interfaces can change how people think and approach a control problem, even after removing the support. It is therefore reasonable to believe that ecological interfaces can play an important role in the early stages of deep knowledge development.","Air traffic control (ATC); ecological interface design (EID); human-machine interface; training","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:10dec22b-1a05-44d5-9f22-b00335a7d40f","http://resolver.tudelft.nl/uuid:10dec22b-1a05-44d5-9f22-b00335a7d40f","Solution-Space-based ATC support for 4DT heterogeneous aircraft-mix control","Mulder, Max (TU Delft Control & Simulation); Yang, L. (TU Delft Control & Simulation; Nanjing University of Aeronautics and Astronautics); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2019","Future Air Traffic Management concepts will require air traffic controllers to move from a tactical to a strategic way of operation. This paper evaluates two novel concepts which support controllers to perform four-dimensional trajectory management in a contingency situation. The Travel Space Representation and Time-Space Diagram are both solution-space based displays where automation calculates all possible actions in real-time. All decision-making is still to be done by the operator but is greatly facilitated by this automation, as it shows all possible actions at a glance. An experiment is described which evaluated the performance of novice controllers in managing a sector where suddenly a bad weather cell emerged, requiring them to re-route traffic in space and time. Results show that the display concepts work well and support operators even in complex situations with a heterogeneous mix of aircraft types and speeds. Performance and workload indicators become worse for the higher-density, higher-heterogeneity situations.","","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","","","","","","Control & Simulation","","",""
"uuid:3e887db7-9036-4f22-bb4c-d12fcea4babb","http://resolver.tudelft.nl/uuid:3e887db7-9036-4f22-bb4c-d12fcea4babb","Flow-based air traffic control: Human-machine interface for steering a path-planning algorithm","Ten Brink, D. S.A. (Student TU Delft); Klomp, R.E. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","In the near future, air traffic controllers are expected to adhere to stringent time and position constraints in controlling traffic. For this new task, new decision-support tools are required which include higher levels of automation, whilst letting humans remain to be the ultimate responsible for the safety of operations. In previous research, an advanced human-machine interface was designed and evaluated that allows controllers to manipulate four-dimensional flight plans of each individual aircraft. In this research, a higher level of automation is explored by designing a new interface prototype that enables controllers to manipulate multiple flows of traffic by facilitating interaction with a path-planning algorithm. A first evaluation of this interface, in which five participants were asked to structure a perturbed airspace as they saw fit, showed that the participants were able to influence the algorithm as they desired and were supported by the interface that visualized the inner workings of the algorithm. However, human influence did not improve the solutions in terms of sector robustness and efficiency, as compared the previously designed interface for aircraft. Therefore, improvements and its use case warrant further research.","","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","","","","","","Control & Simulation","","",""
"uuid:464b0f17-e40d-4d86-91e1-610be3b9c5f6","http://resolver.tudelft.nl/uuid:464b0f17-e40d-4d86-91e1-610be3b9c5f6","Exploring the potential benefits of multi-aircraft trajectory manipulation in future air traffic control","Nagaraj, R. (Student TU Delft); Klomp, R.E. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","Future Air Traffic Management is expected to shift towards four dimensional trajectory (4DT) management, requiring new decision support tools for air traffic controllers to meet stringent time and position constraints. In previous work, a prototype human-machine interface has been developed for 4D trajectory manipulations of single aircraft. This paper describes a tool for multi-aircraft manipulation and investigates its potential control efficiency benefits. A human-in-the-loop experiment (N = 13) has been conducted using scenarios with sector disruptions and varying conflict geometry. Results show that participants preferred to use multi-aircraft manipulation for groups of aircraft having small convergence angles. Since the current implementation involves re-routing all selected aircraft through one common waypoint (referred to as a 'merge point'), extra additional track miles were flown and airspace robustness reduces. Regarding efficiency and safety, multi-aircraft trajectory manipulation seems favourable only for smaller convergence angles, although this also depends on the way the operators place the aircraft merging points. For future development, attention should be devoted to making flight efficiency constraints of each aircraft more salient, enabling controllers to better time the rerouting multiple aircraft and more fairly distribute re-routing costs.","","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","","","","","","Control & Simulation","","",""
"uuid:5519da60-7d60-42ed-a149-2c162d28281a","http://resolver.tudelft.nl/uuid:5519da60-7d60-42ed-a149-2c162d28281a","Systematically quantifying oil–water microemulsion structures using (spin-echo) small angle neutron scattering","Mulder, Maarten (Student TU Delft); Li, Xuesong X. (Shell Global Solutions International B.V.); Nazim, M.M. (TU Delft ImPhys/Practicum support); Dalgliesh, Robert M. (Rutherford Appleton Laboratory); Tian, B. (TU Delft RST/Neutron and Positron Methods in Materials); Buijse, Marten (Shell Global Solutions International B.V.); van Wunnik, John (Shell Global Solutions International B.V.); Bouwman, W.G. (TU Delft RST/Neutron and Positron Methods in Materials)","","2019","Microemulsion systems consisting of D2O, an alkane, an anionic internal olefin sulfonate surfactant, salt and secondary butyl alcohol (SBA) as co-solvent are studied in a systematic way. In four different sample sets, either the salt content, SBA content or alkane carbon number was varied in order to study the effects of the individual compounds on the structure sizes making up the microemulsion. Using complementary small-angle neutron scattering techniques SANS and Spin-Echo SANS, it was found that the microemulsion systems exhibit the largest structures in the optimum state (domain size of d/2 =144 nm in the model by Teubner and Strey), where the structure is considered bicontinuous. In comparison, at under- and over-optimum states where the structures consist of emulsified spherical droplets, the smallest measured diameter was 2R = 44 nm. Furthermore, the structure sizes in bicontinuous microemulsions decrease exponentially (down to d/2 =15 nm for pentadecane and 5 wt% SBA) as function of both SBA content and alkane carbon number. The observed trends in structure sizes combined with the trends observed in the area per surfactant molecule, are qualitatively explained with the extended Winsor R-ratio, the HLD-NAC model and surfactant film flexibility arguments.","","en","journal article","","","","","","","","","","","ImPhys/Practicum support","","",""
"uuid:0d5929e2-3c0e-4f4b-8bb2-e7ee5b1e9b6a","http://resolver.tudelft.nl/uuid:0d5929e2-3c0e-4f4b-8bb2-e7ee5b1e9b6a","Modelling wing wake and tail aerodynamics of a flapping-wing micro aerial vehicle","Armanini, S.F. (TU Delft Control & Simulation); Caetano, J. V. (Portuguese Air Force Research Center); de Visser, C.C. (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); de Croon, G.C.H.E. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","Despite significant interest in tailless flapping-wing micro aerial vehicle designs, tailed configurations are often favoured, as they offer many benefits, such as static stability and a simpler control strategy, separating wing and tail control. However, the tail aerodynamics are highly complex due to the interaction between the unsteady wing wake and tail, which is generally not modelled explicitly. We propose an approach to model the flapping-wing wake and hence the tail aerodynamics of a tailed flapping-wing robot. First, the wake is modelled as a periodic function depending on wing flap phase and position with respect to the wings. The wake model is constructed out of six low-order sub-models representing the mean, amplitude and phase of the tangential and vertical velocity components. The parameters in each sub-model are estimated from stereo-particle image velocimetry measurements using an identification method based on multivariate simplex splines. The computed model represents the measured wake with high accuracy, is computationally manageable and is applicable to a range of different tail geometries. The wake model is then used within a quasi-steady aerodynamic model, and combined with the effect of free-stream velocity, to estimate the forces produced by the tail. The results provide a basis for further modelling, simulation and design work, and yield insight into the role of the tail and its interaction with the wing wake in flapping-wing vehicles. It was found that due to the effect of the wing wake, the velocity seen by the tail is of a similar magnitude as the free stream and that the tail is most effective at 50–70% of its span.","aerodynamic modelling; Flapping-wing micro air vehicle; flapping-wing wake; system identification; tail-wing wake interaction; OA-Fund TU Delft","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:134c10b1-1713-4372-91cb-3c4f9549f350","http://resolver.tudelft.nl/uuid:134c10b1-1713-4372-91cb-3c4f9549f350","Time-varying perceived motion mismatch due to motion scaling in curve driving simulation","van Leeuwen, T. D. (Student TU Delft); Cleij, D. (TU Delft Control & Simulation; Max Planck Institute for Biological Cybernetics); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); Bülthoff, H. H. (Max Planck Institute for Biological Cybernetics)","","2019","In motion simulation, motion input scaling is often applied to deal with the limited motion envelopes of motion simulators. In this research, the time-varying effects of scaling the lateral specific force up or down during passive curve driving in a car driving simulation are investigated through a simulator experiment. It is concluded that lateral specific force scaling has a time-varying effect on the perceived fidelity of a curve-driving simulation. In particular, motion scaling during a curve entry is found to be less detrimental than motion scaling during a curve's sustained part and during the curve exit.","Continuous subjective rating; Curve driving; Driving simulators; Motion simulation","en","journal article","","","","","","","","2021-03-21","","Control & Operations","Control & Simulation","","",""
"uuid:e4162ff3-dae4-4e6a-a324-4cbd760b4d2e","http://resolver.tudelft.nl/uuid:e4162ff3-dae4-4e6a-a324-4cbd760b4d2e","Measuring and modeling driver steering behavior: From compensatory tracking to curve driving","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","Drivers rely on a variety of cues from different modalities while steering, but which exact cues are most important and how these different cues are used is still mostly unclear. The goal of our research project is to increase understanding of driver steering behavior; through a measuring and modeling approach we aim to extend the validity of McRuer et al.'s crossover model for compensatory tracking to curve driving tasks. As part of this larger research project, this paper first analyzes the four main differences between compensatory tracking and curve driving: (1) pursuit and preview, (2) viewing perspective, (3) multiple feedback cues, and (4) boundary-avoidance strategies due to available lane width. Second, this paper introduces multiloop system identification as a method for explicitly disentangling the driver's simultaneous responses to various cues, which is subsequently applied to two sets of human-in-the-loop experimental data from a preview tracking and a curve driving experiment. The results suggest that recent human modeling advances for preview tracking can be extended to curve driving, by including the human's adaptation to viewing perspective, multiple feedback cues, and lane width. Such a model's physically interpretable parameters promise to provide unmatched insights into between-driver steering variations, and facilitate the systematic design of novel individualized driver support systems.","Compensatory tracking; Curve driving; Driver modeling; Preview; System identification","en","journal article","","","","","","","","2019-11-01","","Control & Operations","Control & Simulation","","",""
"uuid:8f3f6311-8b12-4ce0-b0ba-41d014396ac7","http://resolver.tudelft.nl/uuid:8f3f6311-8b12-4ce0-b0ba-41d014396ac7","Framework for a Two-step Evaluation of Haptic Displays","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","Haptic displays can greatly facilitate manual control tasks. Their capacity of allowing the operator to perceive the desired dynamics is an important design parameter. However, attempts to evaluate haptic displays on the basis of what dynamics humans actually perceive are scarce. This paper proposes a two-step framework which incorporates the characteristics of human haptic perception into the evaluation of haptic displays. The first step is to evaluate the haptic display based on a recently developed model of the threshold for changes in the perception of system dynamics. It allows us to know the frequency spectrum in which a haptic device alters the operator's perception of the system dynamics. The second step is then to understand how the perceived dynamic distortions affect the operator's characterization of the system dynamics. Findings from recent psychophysical studies allow us to relate the changes in perception caused by the haptic device to changes in the perceived mechanical properties of the system. A numerical example illustrates how haptic displays can be evaluated using the proposed framework.","Augmented Reality; Display Design; Human - Computer Interaction; Virtual","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:f25a572a-337b-4c7f-ade9-53c81c80ebf7","http://resolver.tudelft.nl/uuid:f25a572a-337b-4c7f-ade9-53c81c80ebf7","Methodology Comparison for Designing a Decision-making Support System","Reitsma, J.P. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","Designing interfaces for effective decision-making supports for complex, dynamic systems is a challenging task. Besides the already challenging task of determining the visual form, the task of defining the content of these supports can be even more demanding. Especially for an unstable and complex work domain with multiple stakeholders and multiple interrelated systems, e.g., commercial flight operations. Various methodologies for designing such supports have been introduced in the last decades. In this paper two methodologies, Ecological Interface Design (EID) and Applied Cognitive Work Analysis (ACWA) are compared to determine what methodology is best suited for the design of an in-flight decision support system. The methodologies are compared on two aspects, (1) development of the knowledge-based model and (2) the means to translate this model into requirements for the actual representation. The functional abstraction network (FAN), as part of the ACWA, is the preferred knowledge-based modelling method for capturing a complex multi-system work domain, like commercial flight operations. Mainly due to the increased flexibility in modeling and ease of extending the model. The ACWA is also found to the preferable method to translate the functional model into representation requirements due to its structured step-wise and system engineering inspired approach.","applied cognitive work analysis; decision support systems; ecological interface design; Human-machine interface","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:4ebcb0ef-4d71-4aae-88ed-ac8a0bdd465a","http://resolver.tudelft.nl/uuid:4ebcb0ef-4d71-4aae-88ed-ac8a0bdd465a","New mass-lumped tetrahedral elements for 3D wave propagation modelling","Geevers, S. (University of Twente); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell); van der Vegt, J (University of Twente)","","2019","We present a new accuracy condition for constructing mass-lumped elements. This condition is less restrictive than the one previously used and enabled us to construct new mass-lumped tetrahedral elements for 3D wave propagation modelling. The new degree-2 and degree-3 elements require significantly fewer nodes than previous versions and mass-lumped tetrahedral elements of higher degree had not been found before. We also present a new accuracy condition for evaluating the stiffness matrix-vector product. This enabled us to obtain tailored quadrature rules for the new elements that further reduce the computational cost.","mass lumping; tetrahedral element; spectral element; wave equation","en","abstract","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:1890d5f8-0081-453e-b813-040f8dd7d88c","http://resolver.tudelft.nl/uuid:1890d5f8-0081-453e-b813-040f8dd7d88c","Landscape of participatory city makers: A distinct understanding through different lenses","de Koning, J.I.J.C. (TU Delft Design for Sustainability); Puerari, E. (Rijksuniversiteit Groningen); Mulder, I. (TU Delft Design Conceptualization and Communication); Loorbach, Derk (DRIFT: Dutch Research Institute for Transitions)","","2019","Today, citizens, professionals, civil servants, social enterprises, and others form different types of coalitions to overcome the challenges facing our modern cities. In this paper, the particularities of these types of groups are characterised and categorised into ten different types of city makers. Generally, these types of city makers bring value to cities, but we conclude that this value could be enriched through more participatory approaches that stimulate crossovers and accelerate the transition towards sustainable futures. Therefore, we characterise the different identified types as potential ‘participatory’ city makers. However, these participatory approaches and the networks between them still need to be developed, while improving conditions and dynamics that can enable and enhance innovation in urban environments. Design and systems thinking could contribute valuable methods and perspectives to the development of these participatory and systemic approaches. Finally, the categorisation presented in this paper must enable a better understanding of the transformative capacity of these different types of city makers, necessary for flourishing and sustainable communities.","","en","journal article","","","","","","","","","","","Design for Sustainability","","",""
"uuid:b42d4f09-68a4-4af0-8647-303f8b3d7704","http://resolver.tudelft.nl/uuid:b42d4f09-68a4-4af0-8647-303f8b3d7704","Join the Park!: Exploring Opportunities to Lower the Participation Divide in Park Communities","Slingerland, G. (TU Delft System Engineering); Mulder, I. (TU Delft Design Conceptualization and Communication); Jaśkiewicz, T.J. (TU Delft Design Conceptualization and Communication)","Cech, Florian (editor); Tellioglu, Hilda (editor)","2019","The current work explores the participation divide that is oftentimes at play within local citizen communities. The studied case illustrates a common situation where the majority of local citizens does not participate in public space improvement and maintenance activities organised by local community activists. The presented research involved semi-structured interviews supported by interactive service design probes. It has led to two strategies for stimulating community participation, namely 1) increasing transparency around community activities, and 2) embedding community participation in citizens' daily social practices.","Local communities; Design strategies; Citizen participation","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","System Engineering","","",""
"uuid:3321c0b3-7408-4685-9dfc-f8f75268ea95","http://resolver.tudelft.nl/uuid:3321c0b3-7408-4685-9dfc-f8f75268ea95","Operational alerting on modern commercial flight decks","Reitsma, J.P. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","Tsang, P.S. (editor); Vidulich, M.A. (editor); van Paassen, M.M. (editor)","2019","The glass cockpit and EFB enable new ways of information presentation and interaction on the flight deck of modern commercial jets. This information supports crews in flight plan management, which essentially entails evaluating the plan against (ever-changing) flight constraints and, if necessary, modifying it. Flight constraints emerge from the interaction between the system and its operational environment. Understanding the constraints, and checking the flight plan against these constraints, requires selection and combination of information from many sources. Operational alerting can support this process, by prioritizing and formatting information to match the operational context. A number of modern flight deck systems are evaluated on how they support alerting in an operational ready format. From the comparison we can conclude, that there is a trend towards operational alerting, especially on a tactical level.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:f7a8cf7c-5cc9-4d4f-9d7b-63875fd59077","http://resolver.tudelft.nl/uuid:f7a8cf7c-5cc9-4d4f-9d7b-63875fd59077","Operational alerting concept for commercial single pilot operations systems","Reitsma, J.P. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","Tsang, P.S. (editor); Vidulich, M.A. (editor); van Paassen, M.M. (editor)","2019","Reducing high workload levels are a major challenge to enable single pilot operations. Where the pilot is currently supported with many automated systems, the role of mission planner is relatively unsupported, i.e., the flight crew is required to integrate and combine information from various sources to extract the implications on the missions’ high-level goals to determine if the mission can still be completed safely and successfully. An operational alerting display is developed to provide the pilot with a clear overview of the current and future operational flight constraints. This enables the pilot to determine if the initial plan is valid under the existing conditions. The display is not limited to system malfunctions, but combines the full spectrum of operational constraints, e.g., weather and airport operations. The display concept was tested on usability with a commercial pilot to provide a preliminary performance indication on the effectiveness of the concept.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:550de1f2-030f-4c2d-857d-0a5ec232c7c5","http://resolver.tudelft.nl/uuid:550de1f2-030f-4c2d-857d-0a5ec232c7c5","Pilot evaluations of a non-verbal startle and surprise management method, tested during airline recurrent simulator training","Landman, H.M. (TU Delft Control & Simulation; TNO); Groen, E.L. (TNO); Frank, M (Luxair Luxembourg); Steinhardt, G. (Cargolux International Airlines); van Paassen, M.M. (TU Delft Control & Simulation); Bronkhorst, A (TNO); Mulder, Max (TU Delft Control & Simulation)","Tsang, P.S. (editor); Vidulich, M.A. (editor); van Paassen, M.M. (editor)","2019","Aviation safety organizations have recommended that airline pilots are trained for startle and surprise. However, little information is available on useful training interventions. Therefore, a training intervention trial was executed during airline recurrent simulator training. The method consisted of a slow visual scan from the side-window, over the instruments, ending with facing the other pilot. Following a recorded video instruction, 38 airline pilots in two-pilot crews performed a training scenario in which they could apply the method. Data on application and evaluation of the method were obtained from each pilot. Few pilots actually applied the method (18.4%), and many gave low ratings to applicability of the method in the scenario, as well as in operational practice. Results show that a startle management method, as well as manner in which it is trained, should be carefully evaluated before being implemented in training practice.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:6d2649ac-f537-4d0c-98bd-5a6799b5c5b6","http://resolver.tudelft.nl/uuid:6d2649ac-f537-4d0c-98bd-5a6799b5c5b6","emg3d: A multigrid solver for 3D electromagnetic diffusion","Werthmüller, D. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2019","Controlled-source electromagnetic (CSEM) surveys are a common geophysical investigationtool in the search for, amongst other, groundwater, hydrocarbons, and minerals. The nu-merical modelling of CSEM data requires the solution of the Maxwell equations. These canbe simplified in the particular case of CSEM, as the frequencies used in surveys are usuallysufficiently low to ignore any displacement currents. A diffusive problem remains, which hasthe resulting system of equations given in the frequency domain byE","","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:63881646-8ac9-4cad-93de-26512bd926f5","http://resolver.tudelft.nl/uuid:63881646-8ac9-4cad-93de-26512bd926f5","Testing the applicability of a checklist-based startle management method in the simulator","Landman, H.M. (TU Delft Control & Simulation); van Middelaar, S.H.; Groen, Eric L. (TNO); van Paassen, M.M. (TU Delft Control & Simulation); Bronkhorst, Adelbert W. (TNO); Mulder, Max (TU Delft Control & Simulation)","","2019","Several checklist-based methods have been proposed to help pilots manage startle in unexpected situations. In the current experiment, we tested how pilots reacted to using such a method, which featured the mnemonic COOL: Calm down – Observe – Outline – Lead. Using a motion-based simulator outfitted with a non-linear aerodynamic model of a small twin-propeller aircraft, twelve pilots practiced using the COOL method before performing four test scenarios involving startling events. Application of the full method in the test scenarios was high (90-100%), and pilots rated the method on average as useful (4 on a 1-5 point Likert scale). The first two steps of the method were seen as the “core” of the method. However, pilots also displayed difficulty with prioritizing dealing with immediate threats over executing the method. The results are promising, but they also warn us to be cautious when introducing a startle management method.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:44a3fa98-e56d-4aad-96a6-b3dd0d5a2ab1","http://resolver.tudelft.nl/uuid:44a3fa98-e56d-4aad-96a6-b3dd0d5a2ab1","On transforming transition design: From promise to practice","van Selm, Maaike (Student TU Delft); Mulder, I. (TU Delft Design Conceptualization and Communication)","Bohemia, Erik (editor); Gemser, Gerda (editor); de Bont, Cees (editor); Fain, Nusa (editor); Assoreira Almendra, Rita (editor)","2019","We are living in transitional times. Much has been under debate on the need to change and to cope with societal transitions, less emphasis, however, is devoted on how to do so. Therefore, one of the primary questions in Transition Design is how to design for sustainabilitytransitions? The current work aims to evaluate ‘transition design studies’ by analysing and evaluating the current available practice of transition design in order to contribute to the field in two ways: first, by maturing through evaluation, and second, by identifying points of further research. Our findings show that three phases can be distinguished within transition design processes: Design researchto understand past, present, and to envision the future; Designing interventionsto create the right thing, at the right place, at the right time, and Design practice for transitionthat accumulate the design interventions in order to drive societal transitions","Design methods; persistent problems; sustainability transitions; systemic change; transition design","en","conference paper","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:2aaf6a31-f72d-48b4-9a4f-d76829155bc0","http://resolver.tudelft.nl/uuid:2aaf6a31-f72d-48b4-9a4f-d76829155bc0","French Biological Philosophy of Technology as a Candidate Perspective Furthering Design Methodology","Mulder, S.S. (TU Delft Methodologie en Organisatie van Design)","Badke Schaub, Petra (editor); Kleinsmann, Maaike (editor)","2019","A first exploration is conducted to what the French biological philosophy of technology perspective has to offer to the field of design methodology. If this French perspective is combined with contemporary speculative pragmatism a generative design methodology emerges offering novelty in what is sensed as important in a design situation. Within this perspective, drawing upon the late French philosopher Gilbert Simondon, technical objects have their own mode of existence and their own trajectory of development apart from human intention.
Designers working with such a generative design methodology follow the constitutive value of openness and attune to the regulative value of techno-aesthetic judgments. By way of a 'vignette+', a paradigmatic example from a real case, a more encompassing argument is made towards design situations where a sophisticated machine is 'inserted' into a domestic setting.
The example taken is the use of an artificial kidney machine in a domestic setting and the development of a novel machine with a design team. Four aspects were sensed as important in the unfolding design situation and directions for further research are discussed.","Design methodology; Design methods; Simondon; Techno-aesthetics; Technology","en","conference paper","Cambridge University Press","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:07688e6d-e330-4044-8adf-441acbda008c","http://resolver.tudelft.nl/uuid:07688e6d-e330-4044-8adf-441acbda008c","Developing active manipulators in aircraft flight control","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","Most haptic interfaces developed for aircraft control provide haptic support as an additional force on the control manipulator. This study revisits the active manipulator, which is a design concept that is different from but complementary to existing haptic interfaces. This control device sends the force that the pilot exerts on it to the aircraft while feeding back the aircraft rotational rate by means of its deflection angle. It is found that, in comparison with the conventional passive manipulator, the active manipulator greatly facilitates target following and disturbance rejection in compensatory tracking tasks. Furthermore, larger improvements in task performance are associated with higher forcing-function bandwidths. These findings are accounted for by the fact that the active manipulator changes the effective controlled-element dynamics into integratorlike dynamics while at the same time integrating disturbance rejection into the neuromuscular system. However, the high-frequency disturbances acting on the aircraft present in feedback about the aircraft state adversely affect the operational effectiveness of the active manipulator. Based on the experimental findings and results from the passivity theory, a lead-lag filter is designed and evaluated, which mitigates this effect without affecting task performance.","","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:9f572963-db3a-4a76-be2a-cdfd5c2c4268","http://resolver.tudelft.nl/uuid:9f572963-db3a-4a76-be2a-cdfd5c2c4268","Open Innovation Strategies for Sustainable Urban Living","van Genuchten, E.J.S. (TU Delft Design Conceptualization and Communication); Calderon Gonzalez, A. (TU Delft Design Conceptualization and Communication); Mulder, I. (TU Delft Design Conceptualization and Communication)","","2019","Cities are increasingly seen as having an important role in tackling societal challenges related to climate change, while open innovation is increasingly accepted as a new way of working for governments. In the current work, we explore the role of open innovation to tackle global challenges on a city level. In the context of the city of Rotterdam and its vision on sustainability and liveability, seven collaborative initiatives are introduced. These initiatives aim to address both sustainability and liveability goals. Our research shows that in order to have these initiatives contribute to the overall municipal goal on sustainability and liveability, the municipality needs to take different roles. Whereas traditional open innovation literature usually distinguishes three main types of open innovation, namely outside-in, inside-out, and coupled processes, the current study shows that open innovation for sustainability in the city needs a much more fine-grained and elaborate perspective; a multi-level open innovation model that allows for different co-creative partnerships joining forces in sustainability challenges. It can be concluded that governments have a key role in infrastructuring these co-creative partnerships.","cities; co-creative partnerships; infrastructuring; open innovation; public sector; sustainable urban living","en","journal article","","","","","","This article belongs to the Special Issue Open Innovation for Sustainability: An Urban Perspective.","","","","","Design Conceptualization and Communication","","",""
"uuid:190771f7-5a32-4907-b37b-615b763a15b8","http://resolver.tudelft.nl/uuid:190771f7-5a32-4907-b37b-615b763a15b8","Sanitary systems: Challenges for innovation","Eijlander, Sabine (The Hague University of Applied Sciences); Mulder, K.F. (TU Delft Organisation & Governance; The Hague University of Applied Sciences)","","2019","Global society is confronted with various challenges: climate change should be mitigated, and society should adapt to the impacts of climate change, resources will become scarcer and hence resources should be used more efficiently and recovered after use, the growing world population and its growing wealth create unprecedented emissions of pollutants, threatening public health, wildlife and biodiversity. This paper provides an overview of the challenges and risks for sewage systems, next to some opportunities and chances that these developments pose. Some of the challenges are emerging from climate change and resource scarcity, others come from the challenges emerging from stricter regulation of emissions. It also presents risks and threats from within the system, next to external influences which may affect the surroundings of the sewage systems. It finally reflects on barriers to respond to these challenges.","Climate change adaptation and mitigation; Emissions; Load factor; Lock in; Modern sanitary systems; Resource recovery; Sewage effluents","en","journal article","","","","","","","","","","","Organisation & Governance","","",""
"uuid:f398d858-617d-42ae-ba12-62b62b99713f","http://resolver.tudelft.nl/uuid:f398d858-617d-42ae-ba12-62b62b99713f","Sustainable urban innovation strategies","Mulder, K.F. (TU Delft Organisation & Governance; The Hague University of Applied Sciences)","","2019","","","en","contribution to periodical","","","","","","","","","","","Organisation & Governance","","",""
"uuid:9d6ec708-3038-446d-9484-6d1d9fd948f0","http://resolver.tudelft.nl/uuid:9d6ec708-3038-446d-9484-6d1d9fd948f0","Solution space concept: Human-machine interface for 4D trajectory management","Klomp, R.E. (TU Delft Control & Simulation); Riegman, R. (Student TU Delft); Borst, C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2019","The current evolution of the ATM system, led by the SESAR programme in Europe and the NextGen programme in the US, is foreseen to bring a paradigm shift to the work of the air traffic controller. Rather than the current primarily tactical control method, one aims for the introduction of more strategic, 4D (space and time) trajectory management. In both programmes a central role is foreseen for the human operator, aided by higher levels of automation and advanced decision-support tools. Previous work has shown promising results in the design of such automated support tools, however, issues with controller acceptance and intuitiveness were found to be key for their overall acceptability. This paper presents a concept decision-support tool for 4D trajectory management that aims to overcome these issues by directly visualizing action-relevant solution spaces. Rather than imposing a certain control strategy, the solution space visualizes all possible control actions, regardless of their optimality. Results of preliminary validation experiments with partial implementations of the solution space representation demonstrated the viability of the concept, but also highlighted areas for improvement.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:bbf68d9e-d156-452a-a24d-78e3a783843a","http://resolver.tudelft.nl/uuid:bbf68d9e-d156-452a-a24d-78e3a783843a","Speeding up a mass-lumped tetrahedral finite-element method for wave propagation","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); Geevers, S. (Universität Wien); van der Vegt, J. (University of Twente)","","2019","Mass-lumped finite elements on tetrahedra offer more flexibility than their counterpart on hexahedra for the simulation of seismic wave propagation, but there is no general recipe for their construction, unlike as with hexahedra. Earlier, we found new elements up to degree 4 that have significantly less nodes than previously known elements by sharpening the accuracy criterion. A similar approach applied to numerical quadrature of the stiffness matrix provides a speed improvement in the acoustic case and an additional factor 1.5 in the isotropic elastic case. We present numerical results for a homogeneous and heterogeneous isotropic elastic test problem on a sequence of successively finer meshes and for elements of degrees 1 to 4. A comparison of their accuracy and computational efficiency shows that a scheme of degree 4 has the best performance when high accuracy is desired, but the one of degree 3 is more efficient at intermediate accuracy.","","en","conference paper","EAGE","","","","","Accepted Author Manuscript","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:5fc95147-d21c-4e5f-9520-1cb9e75bb2c4","http://resolver.tudelft.nl/uuid:5fc95147-d21c-4e5f-9520-1cb9e75bb2c4","Small-scale-induced anisotropy of a 3D subsurface model: quantitative analysis and numerical simulations of waves within","Cupillard, Paul (Lorraine University); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); Irakarama, Modeste (Lorraine University); Mazuyer, Antoine (Lorraine University; Stanford University); Anquez, Pierre (Lorraine University)","","2019","Within the last decade, non-periodic homogenization proved to be an accurate upscaling method for computing smooth equivalent media of elastic models of the earth interior. Doing so, it reveals the seismic anisotropy induced by small-scale structures and it eases the numerical simulation of wave propagation in complex geological settings by preventing from the use of fine and complex meshes or grids, provided that wave simulators can take anisotropy into account. In the present work, we investigate the small-scale-induced anisotropy of a typical subsurface model, namely the SEG-EAGE overthrust, for a fmax = 10Hz wavefield. We find that the amount of anisotropy can reach 20% locally and that orthorhombic anisotropy can be a poor approximation in some areas, suggesting that the analysis of datasets in terms of orthorhomby may be not relevant. However, while low-symmetry classes of anisotropy are naturally handled by the spectral-element method (SEM), they challenge the finite-difference method (FDM) in terms of implementation and computation cost. To estimate the benefit of using homogenized media in either SEM or FDM codes, we perform numerical simulations in both the initial overthrust model and its smooth version, using either regular SEM meshes or FDM grids of different resolution. We compare the obtained waveforms with a reference solution, which allows us to study the accuracy of the simulations as a function of the computation cost for both the SEM and the FDM.","","en","abstract","","","","","","Accepted Author Manuscript","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:032f005f-280a-40ef-82e7-3070b3ce5535","http://resolver.tudelft.nl/uuid:032f005f-280a-40ef-82e7-3070b3ce5535","Future options for sewage and drainage systems three scenarios for transitions and continuity","Mulder, K.F. (TU Delft Organisation & Governance; The Hague University of Applied Sciences)","","2019","The challenge of sustainable development requires cities to aim for drastic improvements in the systems that support its vital functions. Innovating these systems can be extremely hard, and might take lots of time. A transparent and democratic strategy is important to guarantee support for change. Such a process should aim at developing consensus regarding a basic vision to guide the process of systems change. This paper sketches future options for the development of sanitation- and urban drainage systems in industrialized economies. It will provide an analysis of relevant trends for sewage system innovation. In history, sewage systems have emerged from urban sewage and precipitation removal systems, to urban sewage and precipitation removal and cleaning systems. The challenge for the future is recovering energy and resources from sewage systems while maintaining/improving its sanitary service and lowering its emissions.","Sewage systems; Systems innovation; Systems strategy; Urban sustainability","en","journal article","","","","","","","","","","","Organisation & Governance","","",""
"uuid:0c67dcc0-b912-4151-bf6f-5aa5c5a7ee61","http://resolver.tudelft.nl/uuid:0c67dcc0-b912-4151-bf6f-5aa5c5a7ee61","Research through Design for accounting values in design","Conversano, I. (Student TU Delft); del Conte, Livia (Student TU Delft); Mulder, I. (TU Delft Design Conceptualization and Communication)","Giaccardi, Elisa (editor); Stappers, Pieter Jan (editor)","2019","Although Value Sensitive Design offers a theoretical and methodological framework to account for values in design, many questions and controversies are left. The current work aims to contribute to this value debate, by taking stock of large Research through Design (RtD) programs including their developed artifacts, to explore to what extent the explicit and tacit knowledge generated enabled actors to make public and cultural values explicit. Differently put, seven ongoing RtD projects have been studied in an elaborate RtD process articulated in three phases, differentiating in their focus: 1) understanding the values involved in the RtD projects; 2) share insights to steer peer debate on Research on Values, and 3) co-analyse the data and generate further insights. The current research brings forward two main contributions to the RTD community. On the one hand, using ongoing RtD projects in an RtD approach provides a kaleidoscopic perspective on how research and design constantly inform each other through the application of design. On the other hand, the adoption of this kaleidoscopic RtD approach in the context of multidisciplinary research on values acts as a catalyst that generated knowledge and insights to stimulate the debate on accounting values in design research.","artifacts; awareness; definition; ethics; explicit; tools; values","en","conference paper","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:7277028c-a059-477e-8be4-06273aae0f50","http://resolver.tudelft.nl/uuid:7277028c-a059-477e-8be4-06273aae0f50","Evaluation of a Haptic Feedback System for Flight Envelope Protection","van Baelen, D. (TU Delft Control & Simulation); Ellerbroek, Joost (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","Modern fly-by-wire aircraft use flight envelope protection systems, whose actions are not always clear to pilots. To promote situation awareness, proximity to the limits of the flight envelope can be communicated using haptic feedback, by providing forces through the control device. Such a system was developed and this paper reports on the evaluation experiment. Professional pilots were invited to fly an Airbus A320 model in the Delft University of Technology Simona research simulator. A windshear and an icing scenario were flown using a full and degraded control law, with and without the haptic feedback system. The objective results show that the haptic feedback system does not lead to significant improvements in either performance or safety metrics, but also does not interfere with nominal pilot tasks. In the debriefing questionnaire, however, pilots expressed a clear preference for the haptic system. Recommendations for future research include the addition of visual support to complement the haptic cues, and the redesign of the scenarios to allow pilots more freedom in control.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:71424691-9987-4255-afe4-bf618aee417c","http://resolver.tudelft.nl/uuid:71424691-9987-4255-afe4-bf618aee417c","Eigenmode Distortion Analysis for Motion Cueing Evaluation in Fixed-Wing Aircraft Simulators","Stoev, Stanimir (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Miletović, I. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","The Eigenmode Distortion (EMD) analysis is a novel method for objective evaluation of simulator motion cueing fidelity, developed at Delft University of Technology. It expresses the distortions of the perceived motion cues in terms of the dynamic modes of a linear model of the vehicle and has been applied to assess rotorcraft simulations. This paper presents the adaptation of EMD for fixed wing aircraft, including performing the analysis at the pilot station instead of the centre of gravity. The method is applied to a combined linear model of a Cessna Citation 500 aircraft and the Classical Washout Algorithm (CWA). EMD is compared to the current state-of-the-art objective method, the Objective Motion Cueing Test (OMCT), which does not consider the dynamics of the simulated vehicle in its analysis. The two methods show different results in their cueing fidelity assessment of fourCWA configurations. An experiment with six pilots is performed in the SIMONA Research Simulator to test the capability of EMD and OMCT to predict the cueing fidelity as perceived by pilots. The subjects perform pairwise comparisons between the four CWA configurations by exciting the short period dynamics of the aircraft. Results indicate that preferences vary considerably between pilots, causing both EMD and OMCT to show poor, but similar, predictive capabilities.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:4b9e7649-f39f-4ee5-910a-8a8af92ceea3","http://resolver.tudelft.nl/uuid:4b9e7649-f39f-4ee5-910a-8a8af92ceea3","Mitigating the Coriolis Effect in Human Centrifuges by coherent G-misalignment","Mkhoyan, T. (TU Delft OLD SnC Culture; TU Delft Aerospace Structures & Computational Mechanics); Wentink, Mark (Desdemona B.V.); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); de Graaf, B (Desdemona B.V.)","","2019","When coupled with additional degrees of freedom, centrifuge-based motion platforms can combine the agility of an hexapod-basedmotion platform with the ability of sustaining higher Glevels and an extended motion space. This combination of motion characteristics is required for realistic simulation of extreme flight scenarios. However, a false and often nauseating sensation of rotation, the so-called Coriolis effect, induced by the central yaw rotation, combined with the simultaneous rotation of the centrifuge cabin (passive Coriolis effect), or pilot’s head (active Coriolis effect), is the main disadvantage of any centrifuge-based motion platform. For this reason, the majority of human centrifuges are used solely as passive G-trainers in relatively short sessions. This paper discusses the development of a novel motion filter which aims to minimize the undesired Coriolis effects, by allowing for small mismatches in the alignment of pitch or roll coordination. Numerical studies showed that this Coherent Alignment Method (COHAM), is capable of reducing the angular accelerations, while constrained to operate within a region of coherent alignment, the Coherent Alignment Zone. In order obtain data to construct the CAZ region, i.e., establish body tilt thresholds in pitch and roll, an experiment was carried out in the Desdemona motion simulator. Results show higher thresholds in pitch and also higher ambiguity in pitch perception. A follow-up study is planned to further develop and experimentally validate our novel, predictive motion filter, based on the established CAZ region.","","en","conference paper","","","","","","","","","","","OLD SnC Culture","","",""
"uuid:e29968e3-0d66-4a1e-9657-143b01e4d958","http://resolver.tudelft.nl/uuid:e29968e3-0d66-4a1e-9657-143b01e4d958","A Simulator Comparison Study into the Effects of Motion Filter Order on Pilot Control Behavior","Pieters, Marc (Student TU Delft; San Jose State University Research Foundation / NASA Ames Research Center); Zaal, P.M.T. (TU Delft Control & Simulation; San Jose State University Research Foundation / NASA Ames Research Center); Pool, D.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","This paper describes an experiment investigating the effects of motion filter order on human manual control tracking behavior and performance. The experiment was performed on two simulators: the Vertical Motion Simulator at NASA Ames Research Center and the SIMONA Research Simulator at Delft University of Technology. Eighteen pilots in the Vertical Motion Simulator and twenty pilots in the SIMONA Research Simulator performed the experiment with a full factorial variation of three motion filter orders and two motion filter frequencies, in addition to a reference no-motion and full-motion condition. Motion shaping filters derived from Objective Motion Cueing Test measurements on the Vertical Motion Simulator were included in the SIMONA Research Simulator motion logic to match the motion cues between both simulators. Furthermore, the side sticks were set to matching characteristics and the visual cues were matched in terms of time delay, graphics size and screen characteristics. With increased motion filter order, pilots showed worse performance and a lowered contribution of motion feedback in their control strategy. Increasing the motion filter break frequency had similar effects, which were stronger than the effects of increasing the motion filter order, for the eight experimental conditions that were considered in this experiment. For the same motion condition the simulators showed offsets in the results. However, the trends between the motion conditions were similar, leading to the conclusion that for simulator comparisons relative trends are easier to replicate between simulators than absolute results within one condition.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:9f0bc7a2-7010-4de1-9310-31794c28483d","http://resolver.tudelft.nl/uuid:9f0bc7a2-7010-4de1-9310-31794c28483d","Simulator Evaluation of a Medium-Cost Variable Stability System for a Business Jet","Mirza, Abdullah (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, T.J. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","This paper discusses an approach to convert the longitudinal dynamics of the Cessna Citation into a variable stability platform using response feedback, thereby enabling it to take different positions on the Control Anticipation Parameter (CAP) handling quality criterion. The different positions of an aircraft on the criterion reflect different handling qualities, short period damping ratios and CAP. An experiment is performed to investigate whether the handling qualities found analytically, as a result of a variable stability control law, match those found practically from pilot tests on an aircraft simulator. Results of the experiment show that pilots are able to sensitive to even small changes in aircraft dynamics caused by the variable stability system, however, their judgment of the handling qualities does not always agree with handling qualities predicted analytically from the CAP criterion.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:3a3a8296-70aa-48b2-b25a-66ccf87a46c5","http://resolver.tudelft.nl/uuid:3a3a8296-70aa-48b2-b25a-66ccf87a46c5","Revisiting Active Manipulators in Aircraft Flight Control","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","This study revisits the active manipulator developed for manual aircraft control. The active manipulator sends the force applied by the pilot to the aircraft while feeding back the aircraft rotational velocity bymeans of its deflection angle. We find that the activemanipulator, in comparison with the conventional passive manipulator, greatly facilitates target following and disturbance rejection in compensatory tasks. We also find that greater improvements in task performance are associated with higher forcing-function bandwidths. The findings are accounted for by the fact that the active manipulator changes the effective controlled element dynamics into an integrator, and integrates the disturbance rejection into the neuromuscular system. Furthermore, we demonstrate that the haptic feel of the activemanipulator depends on the dynamics of the aircraft. With further exploration, we reveal that human haptic perception of the active manipulator could be characterized by mass-spring-damper properties.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:08958bf0-e2d4-4111-a1df-5b750e883752","http://resolver.tudelft.nl/uuid:08958bf0-e2d4-4111-a1df-5b750e883752","A Unifying Theory of Driver Perception and Steering Control on Straight and Winding Roads","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","Novel driver support systems potentially enhance road safety by cooperating with the human driver. To optimize the design of emerging steering support systems, a profound understanding of driver steering behavior is required. This article proposes a new theory of driver steering, which unifies visual perception and control models. The theory is derived directly from measured steering data, without any a priori assumptions on driver inputs or control dynamics. Results of a human-in-the-loop simulator experiment are presented, in which drivers tracked the centerline of straight and winding roads. Multiloop frequency response function (FRF) estimates reveal how drivers use visual preview, lateral position feedback, and heading feedback for control. Classical control theory is used to model all three FRF estimates. The model has physically interpretable parameters, which indicate that drivers minimize the bearing angle to an 'aim point' (located 0.25-0.75 s ahead) through simple compensatory control, both on straight and winding roads. The resulting unifying perception and control theory provides a new tool for rationalizing driver steering behavior, and for optimizing modern steering support systems.","Control theory; Driver steering; multiloop control; preview information; Roads; system identification; Task analysis; Vehicle dynamics; Vehicles; visual perception; Visualization; Windings","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:1f3e33ec-b3f8-41b6-a59f-3998da1abb7c","http://resolver.tudelft.nl/uuid:1f3e33ec-b3f8-41b6-a59f-3998da1abb7c","In-memory database acceleration on FPGAs: a survey","Fang, J. (TU Delft Computer Engineering); Mulder, Yvo T.B. (IBM Research); Hidders, Jan (Vrije Universiteit Brussel); Lee, Jinho (Yonsei University); Hofstee, H.P. (TU Delft Computer Engineering; IBM Austin Research Lab.)","","2019","While FPGAs have seen prior use in database systems, in recent years interest in using FPGA to accelerate databases has declined in both industry and academia for the following three reasons. First, specifically for in-memory databases, FPGAs integrated with conventional I/O provide insufficient bandwidth, limiting performance. Second, GPUs, which can also provide high throughput, and are easier to program, have emerged as a strong accelerator alternative. Third, programming FPGAs required developers to have full-stack skills, from high-level algorithm design to low-level circuit implementations. The good news is that these challenges are being addressed. New interface technologies connect FPGAs into the system at main-memory bandwidth and the latest FPGAs provide local memory competitive in capacity and bandwidth with GPUs. Ease of programming is improving through support of shared coherent virtual memory between the host and the accelerator, support for higher-level languages, and domain-specific tools to generate FPGA designs automatically. Therefore, this paper surveys using FPGAs to accelerate in-memory database systems targeting designs that can operate at the speed of main memory.","Acceleration; FPGA; High bandwidth; In-memory database; Survey","en","journal article","","","","","","","","","","","Computer Engineering","","",""
"uuid:4bc7fbc6-fe71-48ea-ba3b-3730313248ba","http://resolver.tudelft.nl/uuid:4bc7fbc6-fe71-48ea-ba3b-3730313248ba","On digital citizenship and data as a new commons: Can we design a new movement?
","Mulder, I. (TU Delft Design Conceptualization and Communication); Jaśkiewicz, T.J. (TU Delft Design Conceptualization and Communication); Morelli, Nicola (Aalborg University)","","2019","Along with the urgent need to reinvent our society, a series of paradigm shifts are already shaping transitions toward a more participatory and digital society. The current work takes stock of the promise of open data as a new resource and elaborates upon the maker movement, which has spurred people’s capacity to participate and has provided tools and infrastructures to unleash people’s intrinsic ability to create and innovate. We explore how open data can be a new commons, discuss how hackathons can support digital citizenship, and reflect on the role of Transition Design in creating ecosystems around the common resource and in building capacity","capacity building; data literacy; diffuse design; digital citizenship; hackathons; open data; paradigm shift; societal challenges; Transition Design","es","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:d2b69bd1-c898-4385-9f23-337b84155ca1","http://resolver.tudelft.nl/uuid:d2b69bd1-c898-4385-9f23-337b84155ca1","Framework for human haptic perception with delayed force feedback","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Human-Robot Interaction); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2019","Time delays in haptic teleoperation affect the ability of human operators to assess mechanical properties (damping, mass, and stiffness) of the remote environment. To address this, we propose a unified framework for human haptic perception of the mechanical properties of environments with delayed force feedback. In a first experiment, we found that the delay in the force feedback led our subjects to underestimate all the three mechanical properties. Moreover, subjects perceived additional damping or stiffness properties that the environment did not possess. It was found that the extents of these changes in the perception depend on both time-delay magnitude and the frequency of the movement with which subjects interacted with the environment. This was due to the fact that subjects were not able to distinguish the delay-caused phase shift in the movement-force relation from changes in the three mechanical properties. Based on this, we proposed a framework that allowed for a prediction of the change associated with delayed force in perception of mass-spring-damper environments. The framework was corroborated by a second experiment, in which a combined mass-damper environment was tested. Our hypotheses that the delay would cause subjects to underestimate the mass but overestimate the damping and that the extents of the under- A nd overestimation would differ between individual subjects due to the difference in the interaction frequency were confirmed.","Delays; Force; Force feedback; Haptic perception; haptics; Manipulators; mechanical properties; Springs; Task analysis; teleoperation; time delay","en","journal article","","","","","","Accepted Author Manuscript","","","","Control & Operations","Control & Simulation","","",""
"uuid:c56764c4-db87-465f-ad1b-9cf64c24e2cc","http://resolver.tudelft.nl/uuid:c56764c4-db87-465f-ad1b-9cf64c24e2cc","Adventure :: Expedition to Pragmatism and Inventivism in the design situation","Mulder, S.S. (TU Delft Methodologie en Organisatie van Design); Boess, S.U. (TU Delft Applied Ergonomics and Design); Fritsch, Jonas (IT University of Copenhagen)","Prendeville, Sharon (editor); Leahy, Keelin (editor); Durrant, Abigail (editor); O' Murchú, Nora (editor)","2019","In this Conversation session we explored the two contrasting philosophical perspectives of Pragmatism and Inventivism. Pragmatism tends to focus on technical objects as fulfilling a purpose for mankind in a concrete situational context. In contrast, the French philosopher Gilbert Simondon introduces an Inventivist philosophical position in which technical objects a) have their own mode of being called technicity, b) are becoming more open, and c) should not be reduced to a purpose, as that hinders their co-emergence with mankind - a problematic position with regards to design. The Conversation took the form of exploring an imaginary design case revolving around using the technology of a wildlife camera to design for a dinner table setting. Two imaginary design teams were formed, each operating in a philosophical 'clearing' representing one of the perspectives. Moderators supported each team. Each team had a wildlife camera at their disposal to work with, which at the same time captured each session at selected points. Four participants joined the Conversation session, two per clearing. Halfway through the session the participants reflected intermediately and then one each swapped clearings. The last 10 minutes were spent on a joint reflection. This exploration indicates how the differences in philosophical positions play out when entering concrete design consideration.","Pragmatism; Inventivism; Design Philosophy; Design situations","en","conference paper","Design Research Society","","","","","","","","","","Methodologie en Organisatie van Design","","",""
"uuid:a7689868-6ab0-4d9a-85b5-685a65d4ed26","http://resolver.tudelft.nl/uuid:a7689868-6ab0-4d9a-85b5-685a65d4ed26","Dual-axis manual control: Performance degradation, axis asymmetry, crossfeed, and intermittency","Barendswaard, S. (TU Delft Human-Robot Interaction); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2019","Vehicle control tasks require simultaneous control of multiple degrees-of-freedom. Most multi-axis human-control modeling is limited to the modeling of multiple fully independent single axes. This paper contributes to the understanding of multi-axis control behavior and draws a more realistic and complete picture of dual-axis manual control. A human-in-the-loop experiment was performed to study four distinctive phenomena that can occur in multi-axis control: performance degradation, axis asymmetry, crossfeed, and intermittency. In a simulator, three conditions were tested in the presence and absence of physical motion: the full dual-axis control task, single-axis roll task, and single-axis pitch task. Controlled element dynamics, stick dynamics, and forcing functions were equal in all cases. Results show that performance is worse in dual-axis tasks. Performance in roll axis is consistently worse than pitch, thereby proving axis asymmetry. Physical motion improves the performance and stability of the system. The application of independent forcing function signals in both controlled axes resulted in the detection of crossfeed in dual-axis tasks from spectral analysis. Using a novel extended Fourier coefficient method, the identified crossfeed dynamics can explain up to 20% of the measured control inputs and improves modeling accuracy by up to 5%. Dual-axis control behavior is less accurately modeled with linear time-invariant models and is more intermittent.","Aircraft; Analytical models; Crossfeed; cybernetics; Degradation; dual axis; Human factors; man-machine systems; manual control; modeling; Task analysis; Vehicle dynamics; Visualization","en","journal article","","","","","","Accepted Author Manuscript","","","","Control & Operations","Human-Robot Interaction","","",""
"uuid:3062a185-1a10-485b-9e9a-e2bca4fe0faa","http://resolver.tudelft.nl/uuid:3062a185-1a10-485b-9e9a-e2bca4fe0faa","Why novel sanitary systems are hardly introduced?","Blanken, Micha (The Hague University of Applied Sciences); Verweij, Cees (The Hague University of Applied Sciences); Mulder, K.F. (TU Delft Organisation & Governance)","","2019","Innovations are required in urban infrastructures due to the pressing needs for mitigating climate change and prevent resource depletion. In order to address the slow pace of innovation in urban systems, this paper analyses factors involved in attempts to introduce novel sanitary systems. Today new requirements are important: sanitary systems should have an optimal energy/climate performance, with recovery of resources, and with fewer emissions. Anaerobic digestion has been suggested as an alternative to current aerobic waste water treatment processes. This paper presents an overview of attempts to introduce novel anaerobic sanitation systems for domestic sanitation. The paper identifies main factors that contributed to a premature termination of such attempts. Especially smaller scale anaerobic sanitation systems will probably not be able to compete economically with traditional sewage treatment. However, anaerobic treatment has various advantages for mitigating climate change, removing persistent chemicals, and for the transition to a circular economy. The paper concludes that loss avoidance, both in the sewage system and in the waste water treatment plants, should play a key role in determining experiments that could lead to a transition in sanitation.","Anaerobic digestion; Load factor; Lock in; Sanitary systems; Spatial development; Systems innovation; Transitions","en","journal article","","","","","","","","","","","Organisation & Governance","","",""
"uuid:2313c28e-77c6-451a-ba58-a76d9eee64a1","http://resolver.tudelft.nl/uuid:2313c28e-77c6-451a-ba58-a76d9eee64a1","Efficient Quadrature Rules for Computing the Stiffness Matrices of Mass-Lumped Tetrahedral Elements for Linear Wave Problems","Geevers, S. (University of Twente); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); van der Vegt, J.J.W. (University of Twente)","","2019","We present new and efficient quadrature rules for computing the stiffness matrices of mass-lumped tetrahedral elements for wave propagation modeling. These quadrature rules allow for a more efficient implementation of the mass-lumped finite element method and can handle materials that are heterogeneous within the element without loss of the convergence rate. The quadrature rules are designed for the specific function spaces of recently developed mass-lumped tetrahedra, which consist of standard polynomial function spaces enriched with higher-degree bubble functions. For the degree-2 mass-lumped tetrahedron, the most efficient quadrature rule seems to be an existing 14-point quadrature rule, but for tetrahedra of degrees 3 and 4, we construct new quadrature rules that require fewer integration points than those currently available in the literature. Several numerical examples confirm that this approach is more efficient than computing the stiffness matrix exactly and that an optimal order of convergence is maintained, even when material properties vary within the element.","Mass lumping; Quadrature rule; Spectral element method; Tetrahedral element; Wave equation","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:dcf0d4b1-47e4-4345-abc5-534be646049b","http://resolver.tudelft.nl/uuid:dcf0d4b1-47e4-4345-abc5-534be646049b","Pilot Model Development and Human Manual Control Considerations for Helicopter Hover Displays","Friesen, D. (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); Masarati, Pierangelo (Politecnico di Milano); Mulder, Max (TU Delft Control & Simulation)","","2019","Head-down hover displays and instrument panels theoretically provide all necessary 2ight data information to control low-speed helicopter manoeuvring. However, past experiments have shown that head-down displays can incur high workload, control instability, and even loss of control when used as the sole 2ight data source. This paper investigates the reasons for this instability incurred by replacing good outside visuals with a head-down hover display and an instrument panel. A pilot model based on crossover theory is developed for a linear six-degree-of-freedom Bo. helicopter model. Utilising a target trajectory based on-theory and assuming perfect information availability, the developed model can perform the required manoeuvring task with a control time-delay stability margin of . s (with SAS) or . s (without SAS). Then, the actual information availability based on human perception methods and limitations is discussed. A pilot-in-the-loop experiment in the SIMONA Research Simulator qualitatively validates the developed pilot model for good outside visuals. However, the pilot model does not capture the added diZculties of having to utilise the hover display and instrument panel instead of good outside visuals; during the experiment, the task was impossible to complete with only these displays. This is likely caused by an increase in control time-delay, which in turn is caused by the loss of peripheral and flow 1eld information, a more abstract information representation compared to good outside visuals, and the fact that the pilot now needs to scan multiple displays to acquire all necessary 2ight state information. Improving head-down hover display symbology and scaling factors might rectify some, but probably not all of these effects.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:7dc3669d-c1d5-4710-bbc8-dde7266d82a5","http://resolver.tudelft.nl/uuid:7dc3669d-c1d5-4710-bbc8-dde7266d82a5","Supporting Humans in Solving Multi-UAV Dynamic Vehicle Routing Problems","Klein Koerkamp, N.W.; Borst, C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2019","Real-time optimization of Vehicle Routing Problems (VRP) during mission operations raises concerns regarding obtaining a solution within a reasonable timeframe, especially in domains where operations cannot easily be paused and the number of control parameters is high. Humans, however, are heuristic problem solvers and could potentially complement VRP algorithms in providing quickly a workable and safe solution from which the algorithms can further find the optimum. In this study, a visual interface was developed and evaluated aiming to support humans in manually solving a dynamic VRP in which they needed to solve various simulated payload delivery missions, featuring multiple Unmanned Aerial Vehicles, under failure conditions. Experiment results (n = 16) indicate that the interface enabled the majority of participants to quickly solve the perturbed scenarios, although not always in the most efficient way. Interestingly, participants experienced most difficulty in solving the seemingly easier scenarios, featuring less customers and a relatively low number of vehicles compared to the more complex scenarios.","Human-machine interfac; vehicle routing problem; unmanned aerial vehicles","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:2ad67886-6c56-44b8-9c17-795893febfda","http://resolver.tudelft.nl/uuid:2ad67886-6c56-44b8-9c17-795893febfda","Evaluation of a 3D Solution Space-based ATC Workload Metric","Borst, C. (TU Delft Control & Simulation); Somers, V.L.J.; Mulder, Max (TU Delft Control & Simulation)","","2019","Air Traffic Control (ATC) workload is a limiting factor for air traffic growth, creating a need for objective ATC workload metrics. Previous research has shown that the solution space diagram can be a basis for a workload prediction metric. The current solution space metric however, does not incorporate altitude. In this paper, a 3D solution space metric is described and evaluated. An experiment has been conducted to test the relation of the 3D solution space metric with workload and compare it to other workload metrics; the aircraft count, and a quasi-3D metric: the 2D layered solution space and the Instantaneous Self Assessment-based method. Weak correlations with workload were found for all tested metrics and no significant differences were found between them. Although no significant differences were found, the 2D layered metric showed better results than the 3D solution space-based metric, indicating that air traffic controllers might think in 2D layers over fixed altitude ranges rather than considering the complete 3D physical solution space.","Air Traffic Control; mental workload; supervisory control; decision making","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:8cbf901e-1319-4083-8a36-bb54821fc062","http://resolver.tudelft.nl/uuid:8cbf901e-1319-4083-8a36-bb54821fc062","Investigation of the effects of autorotative flare index variation on helicopter flight dynamics in autorotation","Scaramuzzino, Paolo Francesco (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Quaranta, Giuseppe (Politecnico di Milano); Mulder, Max (TU Delft Control & Simulation)","","2019","Autorotation is a flight condition whereby the engine of a helicopter is no longer supplying power to the main rotor system, which is driven solely by the upward flow of the air moving through the rotor. For helicopters, autorotation is a common emergency procedure performed by pilots to safely land the vehicle in the event of a power failure or tail-rotor failure. In the classic analysis of dynamic stability of helicopters in powered flight, it is common practice to neglect the effect of variation of rotor angular velocity, as the rotorspeed is constant. However, this assumption is no longer justified in case of autorotative flight. Therefore, the rotorspeed becomes an additional degree-of-freedom in autorotation, giving rise to a new stability mode that couples with classical rigid-body modes. The present paper aims at understanding the role of the rotorspeed degree-of-freedom in modifying the stability characteristics in autorotation of rotor systems with different autorotative flare indexes. Results show that the helicopter dynamics are considerably affected in autorotation as a consequence of the fact that the rotorspeed degree of freedom couples with the heave subsidence mode. Therefore, autorotation requires a different control strategy by the pilot and should not be mistakenly considered only as an energy management task. Furthermore, the autorotative flare index, used to characterize the autorotative performance during the preliminary design phase of a new helicopter, provides only energy information. Indeed, this paper demonstrates that high values of this index, representative of good autorotative performance in terms of available energy over required energy, may lead to degraded stability characteristics of the helicopter in autorotation.","","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:33339a4f-da8f-449b-8742-a15eaa793de4","http://resolver.tudelft.nl/uuid:33339a4f-da8f-449b-8742-a15eaa793de4","Online Identification of Pilot Adaptation to Sudden Degradations in Vehicle Stability","Plaetinck, Wouter (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2019","Time-varying pilot control identification is essential for better understanding of how pilots respond when faced with sudden changes in the dynamics of the vehicle they control, such as when automatic control and stabilization systems disengage or undergo a mode transition. This paper presents the results of a human-in-the-loop experiment performed at TU Delft to test a promising online pilot identification method, based on recursive low-order ARX identification, developed in earlier work. In the experiment, eight skilled participants performed tracking tasks with time-varying vehicle dynamics, where at an unpredictable moment during each tracking run a sudden degradation in vehicle stability was induced. In addition to controlling the time-varying vehicle, participants were asked to indicate when they detected the change in the vehicle dynamics with a button push. This paper compares the effectiveness of two different approaches to detect the moment when pilot adaptation occurs from online identified pilot parameter traces. Overall, the results indicate that the lag in this detection of identified pilot adaptation is equivalent to the subjective detection times, or less. This implies that these online techniques have clear potential for ensuring timely and effective changes in adaptive pilot support systems.","Aircraft control; Human-Machine interaction in aircraft","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:efee641e-c7e6-4575-b119-df0ec02c6959","http://resolver.tudelft.nl/uuid:efee641e-c7e6-4575-b119-df0ec02c6959","UKF-based Identification of Time-Varying Manual Control Behaviour","Rojer, Jim (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","This paper describes a novel method for time-varying identification of Human Controller (HC) manual control parameters (called UKF-FPV), based on a steady-state (constant state covariance) Unscented Kalman Filter (UKF). This approach requires no a priori assumptions on the shape of HC parameter variations, which is a potential advantage over state-of-the-art methods such as the recently proposed MLE-APV approach, for which a sigmoid-shaped parameter variation is assumed. For a scenario where an HC performs a single-loop compensatory tracking task with time-varying controlled system dynamics, both identification methods are compared using Monte Carlo simulations and human-in-the-loop experiment data. Despite some lag in the HC parameter traces of UKF-FPV, the identification results and the HC model quality-of-fit obtained with both methods were found to match well for both the simulation and experiment data. For the experiment data, UKF-FPV even revealed clear ""local"" changes in HC parameters not captured by the MLE-APV approach, which confirms that HCs adapt unpredictably even in what are considered time-invariant conditions. Overall, the results show that an identification method that requires no a priori assumptions on HC parameter variations is of critical importance for a complete analysis of time-varying HC behaviour.","Cybernetics; manual control; time-varying identification; Unscented Kalman Filter","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:ac3324c8-8b1e-4b50-9789-d2575ae8cc85","http://resolver.tudelft.nl/uuid:ac3324c8-8b1e-4b50-9789-d2575ae8cc85","Manual Control with Pursuit Displays: New Insights, New Models, New Issues","Mulder, Max (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van der El, Kasper (TU Delft Control & Simulation); Drop, F.M. (TU Delft Control & Simulation; Max Planck Institute); van Paassen, M.M. (TU Delft Control & Simulation)","","2019","Mathematical control models are widely used in tuning manual control systems and understanding human performance. The most common model, the crossover model, is severely limited, however, in describing realistic human control behaviour in relevant control tasks as it is only valid for tracking with a compensatory display. This paper first discusses the state-of-the-art in modelling human control in tracking with pursuit displays. It is shown that, although both tasks seem very similar, the separate presentation of target and system output signals allows operators to adopt a huge variety in control strategies, which makes the development of a universal model for pursuit control a challenge. Two recent models are then described which can act as precursors to such a universal model. Third, system identification choices and issues are discussed for pursuit tracking tasks. Finally, it is argued that it is inevitable that time-varying rather than time-invariant methods are needed to properly describe human behaviour in the pursuit tracking task, as skilled operators will learn to characterize the probabilistic nature of the task, which cannot be captured in a single, linear, time-invariant model.","Cybernetics; human-machine interface; manual control; system identification","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:6b40fcf0-0ddf-4e1e-9eb1-9bcff7d170aa","http://resolver.tudelft.nl/uuid:6b40fcf0-0ddf-4e1e-9eb1-9bcff7d170aa","Analysis of Human Skill Development in Manual Ramp-Tracking Tasks","Willems, M. (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); van der El, Kasper (TU Delft Control & Simulation); Damveld, H.J. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","Human modelling approaches are typically limited to feedback-only, compensatory tracking tasks. Advances in system identification techniques allow us to consider more realistic tasks that involve feedforward and even precognitive control. In this paper we study the human development of a feedforward control response while learning to accurately follow a ramp-shaped target signal in the presence of a disturbance acting on the controlled element. An experiment was conducted in which two groups of eight subjects each tracked ramps of different steepnesses in a random or ordered fashion. In addition, ordered runs were followed by a 'surprise' run with a random ramp steepness. Results show that operators learn rapidly, continue to learn during the entire experiment, and can adapt very quickly to surprise situations. Experiments involving learning operators are challenging, as it is difficult to balance-out all experimental conditions and control for inevitable differences between (groups of) subjects.","cybernetics; learning; manual control; modeling; skill","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:35031007-6861-41f2-acc4-c8d326ffe483","http://resolver.tudelft.nl/uuid:35031007-6861-41f2-acc4-c8d326ffe483","Approximating Road Geometry with Multisine Signals for Driver Identification","Kolff, M.J.C. (TU Delft Control & Simulation); van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2019","The understanding of human responses to visual information in car driving tasks requires the use of system identification tools that put constraints on the design of data collection experiments. Most importantly, multisine perturbation signals are required, including a multisine road geometry, to separately identify the different driver steering responses in the frequency domain. It is as of yet unclear, however, to what extent drivers steer differently along such multisine roads than they do for real roads. This paper presents a method for approximating real-world road geometries with multisine signals, and applies it to a stretch of road used in an earlier investigation into driver steering. In addition, a human-in-the-loop experiment is performed to collect driver steering data for both the realistic real-world road and its multisine approximation. Overall, the analysis of driver performance metrics and driver identification data shows that drivers adopt equivalent control behaviour when steering along both roads. Hence, the use of such multisine approximations allows for the realization of realistic roads and driver behaviour in car driving experiments, in addition to supporting the application of quantitative driver identification techniques for data analysis.","driver modeling; driving; manual control; multisine signals; system identification","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:30d0f5d2-f54b-4148-bf9b-620a2c0eaf81","http://resolver.tudelft.nl/uuid:30d0f5d2-f54b-4148-bf9b-620a2c0eaf81","Colloidal Liquid Crystals Confined to Synthetic Tactoids","Gârlea, Ioana C. (University of Vienna; AMOLF); Dammone, Oliver (University of Oxford); Alvarado, José (AMOLF); Notenboom, Valerie (AMOLF); Jia, Yunfei (Forschungszentrum Jülich GmbH); Koenderink, G.H. (TU Delft BN/Gijsje Koenderink Lab; Kavli institute of nanoscience Delft; AMOLF); Aarts, Dirk G.A.L. (University of Oxford); Lettinga, M. Paul (Forschungszentrum Jülich GmbH; Katholieke Universiteit Leuven); Mulder, Bela M. (AMOLF)","","2019","When a liquid crystal forming particles are confined to a spatial volume with dimensions comparable to that of their own size, they face a complex trade-off between their global tendency to align and the local constraints imposed by the boundary conditions. This interplay may lead to a non-trivial orientational patterns that strongly depend on the geometry of the confining volume. This novel regime of liquid crystalline behavior can be probed with colloidal particles that are macro-aggregates of biomolecules. Here we study director fields of filamentous fd-viruses in quasi-2D lens-shaped chambers that mimic the shape of tactoids, the nematic droplets that form during isotropic-nematic phase separation. By varying the size and aspect ratio of the chambers we force these particles into confinements that vary from circular to extremely spindle-like shapes and observe the director field using fluorescence microscopy. In the resulting phase diagram, next to configurations predicted earlier for 3D tactoids, we find a number of novel configurations. Using Monte Carlo Simulations, we show that these novel states are metastable, yet long-lived. Their multiplicity can be explained by the co-existence of multiple dynamic relaxation pathways leading to the final stable states.","","en","journal article","","","","","","","","","","","BN/Gijsje Koenderink Lab","","",""
"uuid:70424a00-b1ce-4089-a03b-de6d9bd75ff6","http://resolver.tudelft.nl/uuid:70424a00-b1ce-4089-a03b-de6d9bd75ff6","Spatiotemporal Quantification of Lithium both in Electrode and in Electrolyte with Atomic Precision via Operando Neutron Absorption","Harks, P.P.R.M.L. (TU Delft ChemE/Materials for Energy Conversion and Storage); Verhallen, T.W. (TU Delft RST/Storage of Electrochemical Energy); George, C. (TU Delft RST/Storage of Electrochemical Energy); van den Biesen, Jan Karel (Student TU Delft); Liu, Q. (TU Delft ChemE/Advanced Soft Matter); Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2019","The commercial uptake of lithium-sulfur (Li-S) batteries is undermined by their rapid performance decay and short cycle life. These problems originate from the dissolution of lithium polysulfide in liquid electrolytes, causing charge and active material to shuttle between electrodes. The dynamics of intractable polysulfide migration at different length scales often tend to escape the probing ability of many analytical techniques. Spatial and temporal visualization of Li in Li-S electrodes and direct mechanistic understanding of how polysulfides are regulated across Li-S batteries starting from current collector and active layer coating to electrode-electrolyte interface are still lacking. To address this we employ neutron depth profiling across Li-S electrodes using the naturally occurring isotope, 6Li, which yields direct spatial information on Li-S electrochemistry. Using three types of Li-S electrodes, namely, carbon-sulfur, carbon-sulfur with 10% lithium titanium oxide (LTO), and carbon-sulfur with LTO membrane, we provide direct evidence for the migration, adsorption, and confinement of polysulfides in Li-S cells at work. Our findings further provide insights into the dynamics of polysulfide dissolution and re-utilization in relation to Li-S battery capacity and longevity to aid rational electrode designs toward high-energy, safe, and low-cost batteries.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:0a9c8424-e9af-4dfd-ac84-1920facae2b7","http://resolver.tudelft.nl/uuid:0a9c8424-e9af-4dfd-ac84-1920facae2b7","Renewable Hydrogen and Electricity Dispatch with Multiple Ni-Fe Electrode Storage","Weninger, B. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2019","","","en","review","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:740fd430-d6d2-412a-a857-6858352214e2","http://resolver.tudelft.nl/uuid:740fd430-d6d2-412a-a857-6858352214e2","Engineering the direct deposition of Si nanoparticles for improved performance in Li-ion batteries","Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Borsa, Dana M. (Meyer Burger (Netherlands)); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2019","In our efforts to address the issues of Si based anodes for Li ion batteries, such as limited active mass loading, rapid capacity degradation and low scalability in manufacturing, we reported a scalable, high mass loading, and additive-free Si nanoparticles (NP) deposition based electrode, but the achieved capacity and cycle life were still limited. In order to improve the reversible capacity and cycling stability of this Si NP deposition electrode, in this work, we have investigated various substrates for Si deposition, including carbon paper (CP), preheated CP and stainless steel felt/mesh (SSF/SSM), and their influences on the electrochemical Li-ion storage performance of the Si NP electrodes. Meanwhile, protective encapsulations of amorphous carbon or silicon nitride on Si NP has been performed and the capabilities of these coatings in improving the cycling stability of Si NP electrodes have been researched. It is found that a carbon-coated Si NP deposition on an SSM substrate achieves an extraordinary cycling stability in electrochemical Li-ion storage for 500 cycles with an average capacity loss of 0.09% per cycle, showing significantly improved commercial viability of Si NP deposition based electrodes in high-energy-density Li-ion batteries.","Batteries - Lithium; Energy Storage; Silicon; Electrode engineering; Lithium-ion batteries; Silicon nanoparticles deposition","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:9f1d6f9c-9543-4501-907e-d3c3bc9b34bd","http://resolver.tudelft.nl/uuid:9f1d6f9c-9543-4501-907e-d3c3bc9b34bd","Immersion precipitation route towards high performance thick and flexible electrodes for Li-ion batteries","Harks, P.P.R.M.L. (TU Delft ChemE/Materials for Energy Conversion and Storage); Robledo, C.B. (TU Delft Energy Technology); George, C. (TU Delft RST/Storage of Electrochemical Energy); Wang, C. (TU Delft RST/Storage of Electrochemical Energy); van Dijk, Thomas (E-Stone); Sturkenboom, Leon (E-Stone); Roesink, Erik D.W. (University of Twente); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2019","Enabling the transition to renewable power sources requires further optimization of batteries in terms of energy/power density and cost-effectiveness. Increasing the practical thickness of Li ion battery electrodes not only can improve energy density on cell level but reduces manufacturing cost. However, thick electrodes exhibit sluggish charge-transport kinetics and are mechanically less stable, typically resulting in substandard battery performance compared to the current commercial standards (~50 μm). Here we disclose a novel method based on immersion precipitation by employing a non-solvent to solidify the battery binder, instead of solvent evaporation. This method allows for the fabrication of thick and suitable density electrodes (>100 μm with ultra-high mass loading) offering excellent electrochemical performance and mechanical stability. Using commercial electrode active materials at a remarkable mass-loading of 24 mg cm−2, the electrodes processed via immersion method are shown to deliver 3.5 mAh cm−2 at a rate of 2C and operate at rates up to 10C. As additional figure of merit, this method produces electrodes that are both stand-alone and highly flexible, which have been evaluated in flexible full-cells. Furthermore, via immersion precipitation the commonly used more toxic N-Methyl-2-pyrrolidone can be supplanted by environmentally benign dimethyl sulfoxide as solvent for processing electrode layers.","Batteries; Electrodes; Flexible batteries; Immersion precipitation; Phase inversion","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:6a193141-0a0b-4ea1-a83d-57e2793e4dcc","http://resolver.tudelft.nl/uuid:6a193141-0a0b-4ea1-a83d-57e2793e4dcc","Analyzing Aircraft Controllability After Engine Failure During Takeoff in Adverse Weather Conditions","Koolstra, H.J. (TU Delft Control & Simulation); Huijbrechts, Erik-Jan (KLM Royal Dutch Airlines); Mulder, J.A. (TU Delft Control & Simulation)","","2019","When an aircraft experiences an engine failure during takeoff, it must be able to either reject or continue the takeoff without exceeding the longitudinal or lateral dimensions of the usable runway. This paper focuses on the lateral deviation. During certification, the minimum control speed ground is determined in certification tests; at this speed, the allowable maximum lateral deviation is 30 ft. These tests are done with a free castering nose wheel and other requirements such as not using ailerons. These are all V mcg increasing factors. On the other hand, the aircraft manufacturer chooses the most favorable conditions, new tires, a dry runway, and no crosswind. It is unclear if the free castering nose wheel is a stringent-enough requirement to compensate for reduced runway friction, and the effect of crosswind is not considered in the certification tests. Furthermore, the rejected takeoff condition is not certified against a lateral excursion limit. Therefore, in this paper, a model is developed to determine the lateral deviation in a continued as well as a rejected takeoff, including the effect of pilot reaction time, runway surface condition, and crosswind. For the present evaluation, a Boeing 737-300 model was used.","","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:5b246061-ee84-402f-bbec-3ff01f99e17f","http://resolver.tudelft.nl/uuid:5b246061-ee84-402f-bbec-3ff01f99e17f","Using Vmcg-Limited V1, Controllability Issues on Contaminated Runways and in Crosswind","Huijbrechts, Erik-Jan (KLM Royal Dutch Airlines); Koolstra, H.J. (TU Delft Control & Simulation); Mulder, J.A. (TU Delft Control & Simulation)","","2019","Vmcg, or ground minimum control speed, is established by aircraft manufacturers during the aircraft certification process. Vmcg is used as a limiting speed for V1 (decision speed) when performing takeoff performance calculations. Performance calculations on contaminated and slippery runways will result in a V1 speed equal to Vmcg-limited V1 for a wide range of takeoff weights when using aircraft manufacturer procedures in a flight crew operationsmanual or computer calculations based on theV1−min policy. In this paper, itwill be shown thatVmcg will not be a safe speed to continue a takeoff after an engine failure in strong crosswind or reduced runway surface friction conditions. A model is used to determine the effect of these environmental conditions on lateral deviation. Apart from the continued takeoff, the lateral deviation in the rejected takeoff after an engine failure was also calculated under different environmental conditions. This resulted in advice for the use of a differential braking technique to prevent a runway excursion if a runway is not dry. A method to mitigate the risk of runway excursion on contaminated and slippery runways is presented. An evaluation, conclusions, and subjects for further research are also presented.","","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:fd65a29b-d211-4a19-af4d-4679d176e1f5","http://resolver.tudelft.nl/uuid:fd65a29b-d211-4a19-af4d-4679d176e1f5","Hacking the hackathon format to empower citizens in outsmarting ""smart"" cities","Jaśkiewicz, T.J. (TU Delft Design Conceptualization and Communication); Mulder, I. (TU Delft Design Conceptualization and Communication); Morelli, Nicola (Aalborg University); Pedersen, Janice S.","","2019","This paper investigates the opportunities of leveraging a hackathon format to empower citizens by increasing their abilities to use open data to improve their neighbourhoods and communities. The presented discussion is grounded in five civic hackathon case studies organised in five European cities. The research revealed specialised learning and collaborative alignment as two mutually complementary aspects of the involved learning processes, which were achieved with the help of high-fidelity and low-fidelity prototypes, respectively. Consequently, the paper identifies and discusses three main factors required to sustain social learning ecosystems beyond hackathon events, and with the purpose of democratising smart city services. These factors include a) supporting individuals in obtaining specific expert knowledge and skills, b) nurturing data- literate activist communities of practice made up of citizens with complementary expert skillsets, and c) enabling members of these communities to generate prototypes of open-data services of varying fidelity.","learning through making; hackathons; open data; prototyping","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:8beb2a2c-af8f-4392-a692-a3130b6f5bfa","http://resolver.tudelft.nl/uuid:8beb2a2c-af8f-4392-a692-a3130b6f5bfa","In-flight Spatial Disorientation Induces Roll Reversal Errors when Using the Attitude Indicator","Landman, H.M. (TU Delft Control & Simulation; TNO); Davies, Simon (Cranfield University); Groen, Eric L. (TNO); van Paassen, M.M. (TU Delft Control & Simulation); Lawson, Nicholas (Cranfield University); Bronkhorst, Adelbert W. (TNO); Mulder, Max (TU Delft Control & Simulation)","","2019","We hypothesized that an incorrect expectation due to spatial disorientation may induce roll reversal errors. To test this, an in-flight experiment was performed, in which forty non-pilots rolled wings level after receiving motion cues. A No-leans condition (subthreshold motion to a bank angle) was included, as well as a Leans-opposite condition (leans cues, opposite to the bank angle) and a Leans-level condition (leans cues, but level flight). The presence of leans cues led to an increase of the roll reversal error (RRE) rate by a factor of 2.6. There was no significant difference between the Leans-opposite and Leans-level condition. This suggests that the expectation strongly affects the occurrence of an RRE, and that people tend to base their responses on motion cues instead of on information on the AI. We conclude that expectation and spatial disorientation have a large effect on piloting errors and may cause hazardous aircraft upsets.
We propose to achieve this in a playful and immersive manner, which is a more familiar and convenient way to introduce children to new concepts. For this we developed Save Schrödinger’s Cat, a puzzle game in virtual reality featuring a classical physics mode and a quantum physics mode. As virtual objects and phenomena behave differently in each mode, this mechanic encourages players to toggle between modes, in order to explore the differences between quantum and classical physics in an immersive, entertaining and challenging way. A preliminary evaluation showed that players could better identify various distinguishing features of either mode.","Classical physics; Educational games; Quantum physics; Virtual reality","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-05-01","","","Computer Graphics and Visualisation","","",""
"uuid:cc03edc6-6d59-4f6d-be06-5a212d50b867","http://resolver.tudelft.nl/uuid:cc03edc6-6d59-4f6d-be06-5a212d50b867","Innovation and Design","Concilio, Grazia (Politecnico di Milano); De Götzen, Amalia (Aalborg University); Molinari, Francesco (Anci Toscana); Morelli, Nicola (Aalborg University); Mulder, I. (TU Delft Design Conceptualization and Communication); Simeone, Luca (Aalborg University); Tosoni, Ilaria (Politecnico di Milano); Van Dam, Kirsten (Aalborg University)","Concilio, G. (editor); Tosoni, I. (editor)","2019","The focus of design studies has shifted from a product-centric perspective to a perspective in which value is defined by and co-created with the consumer, rather than embedded in the output. The reasoning hence focuses on the interplay between innovation and design processes. Moving from an earlier conceptualization of design-driven innovation, the attempt is to define the space of interaction between the different components of the innovation process. In this way a 3D innovation space can be sketched where different practices and experiences can be mapped. Through this exercise the key hypothesis of this work is empowered: no innovation is possible without design.","","en","book chapter","Springer","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:be0be1e4-b53b-4a90-99ab-d66c16a73f4b","http://resolver.tudelft.nl/uuid:be0be1e4-b53b-4a90-99ab-d66c16a73f4b","Dispersion Properties of Explicit Finite Element Methods for Wave Propagation Modelling on Tetrahedral Meshes","Geevers, S. (University of Twente); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); van der Vegt, J. J.W. (University of Twente)","","2018","We analyse the dispersion properties of two types of explicit finite element methods for modelling acoustic and elastic wave propagation on tetrahedral meshes, namely mass-lumped finite element methods and symmetric interior penalty discontinuous Galerkin methods, both combined with a suitable Lax–Wendroff time integration scheme. The dispersion properties are obtained semi-analytically using standard Fourier analysis. Based on the dispersion analysis, we give an indication of which method is the most efficient for a given accuracy, how many elements per wavelength are required for a given accuracy, and how sensitive the accuracy of the method is to poorly shaped elements.","Discontinuous Galerkin method; Dispersion analysis; Explicit finite element method; Mass lumping; Tetrahedral mesh; Wave equation","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:17b4ed03-8c09-4224-8e73-9b3b464e4dd5","http://resolver.tudelft.nl/uuid:17b4ed03-8c09-4224-8e73-9b3b464e4dd5","Training Pilots for Unexpected Events: A Simulator Study on the Advantage of Unpredictable and Variable Scenarios","Landman, H.M. (TU Delft Control & Simulation; TNO); van Oorschot, P. (TU Delft Aerospace Engineering); van Paassen, M.M. (TU Delft Control & Simulation); Groen, Eric L.; Bronkhorst, Adelbert W. (TNO); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","Objective: This study tested whether simulator-based training of pilot responses to unexpected or novel events can be improved by including unpredictability and variability in training scenarios. Background: Current regulations allow for highly predictable and invariable training, which may not be sufficient to prepare pilots for unexpected or novel situations in-flight. Training for surprise will become mandatory in the near future. Method: Using an aircraft model largely unfamiliar to the participants, one group of 10 pilots (the unpredictable and variable [U/V] group) practiced responses to controllability issues in a relatively U/V manner. A control group of another 10 pilots practiced the same failures in a highly predictable and invariable manner. After the practice, performance of all pilots was tested in a surprise scenario, in which the pilots had to apply the learned knowledge. To control for surprise habituation and familiarization with the controls, two control tests were included. Results: Whereas the U/V group required more time than the control group to identify failures during the practice, the results indicated superior understanding and performance in the U/V group as compared to the control group in the surprise test. There were no significant differences between the groups in surprise or performance in the control tests. Conclusion: Given the results, we conclude that organizing pilot training in a more U/V way improves transfer of training to unexpected situations in-flight. Application: The outcomes suggest that the inclusion of U/V simulator training scenarios is important when training pilots for unexpected situations.","flight simulation; mental models; startle; surprise; training","en","journal article","","","","","","","","","Aerospace Engineering","Control & Operations","Control & Simulation","","",""
"uuid:aaad21b3-df03-4762-bc64-f26ecdc589e2","http://resolver.tudelft.nl/uuid:aaad21b3-df03-4762-bc64-f26ecdc589e2","Ecological Interface Design for Vehicle Locomotion Control","van Paassen, M.M. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); Ellerbroek, Joost (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation); Flach, John M. (Wright State University)","","2018","Ecological interface design (EID) was originally developed in the context of process control but has been extended into many domains where technology has resulted in both changing work demands and increased opportunities for improved interface applications. This paper gives an overview of the application of the EID to the control of vehicle locomotion, either from within the vehicle, as a driver or a pilot, or from the outside, as an operator or a (air traffic) controller. It discusses lessons learned from the application of the EID for the vehicle locomotion control task and focuses on how the methodology can be applied to this domain. Specific issues identified are that the planning and control of a vehicle simultaneously spans multiple time scales and that the interface must be designed considering the format in which the control input is defined. Also, due to the extensive standardization of the instrumentation and training certification, changes introduced by the new displays must initially be additional to the existing displays. Chosen representations must also be shown in a format that matches the current instrumentation and the directly observable outside world.","Aerospace electronics; Aircraft; Control systems; Ecological interface design (EID); human–machine systems; Optical feedback; Optical sensors; Planning; Task analysis; vehicle control","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:db2cf8d7-1535-4826-bd47-57f581395563","http://resolver.tudelft.nl/uuid:db2cf8d7-1535-4826-bd47-57f581395563","Flight Tests on fault-tolerant autopilot control laws in laboratory aircraft Citation II","in 't Veld, A.C. (TU Delft Control & Simulation); Mulder, T.J. (TU Delft Control & Simulation); Looye, Gertjan H.N. (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR))","","2018","The Delft University laboratory aircraft Cessna Citation II has the capability to implement and test new auto pilot control laws. The aircraft is equipped as a Fly-By-Wire testbed, that enables the user to control the aircraft through an experimental computer and directly have control over the control surfaces. An extra control stick is mounted on the righthand side in the cockpit from where the aircraft can be controlled in a closed loop. The gains can be adjusted in-flight. An experimental display in the cockpit showed the setpoints for the rate and direct control in pitch and roll.
The control laws that were tested are developed by the department of aircraft systems dynamics of the German Aerospace Center together with Delft University of Technology. The control laws are based on Incremental Nonlinear Dynamic Inversion (INDI). INDI uses synchronized measurements or estimations of (angular) accelerations and control surface deflections. This way it is not dependent on an airplane model, but it is able to automatically adapt flight control laws to changing dynamic behavior of the aircraft, even in case of major system failures or damage to the airframe. The INDI controller directly controls the current to the control surface actuators.
This paper treats the execution of the test flights.
actively involved with ULLs in the Rotterdam-The Hague region in the Netherlands. Our findings show five distinct types of co-creation elements that relate to specific dynamics of participation, facilitation, and organization. We conclude with a discussion on the ambivalent role of contextualized knowledge and the implications for sustainability transitions.","sustainability transitions; urban innovation; participatory design and planning practices; co-creation; experimentation; Rotterdam; OA-Fund TU Delft","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:b5151d16-80a9-4dde-821a-3f691ac8abbe","http://resolver.tudelft.nl/uuid:b5151d16-80a9-4dde-821a-3f691ac8abbe","A topology of shared control systems: Finding common ground in diversity","Abbink, D.A. (TU Delft Human-Robot Interaction); Carlson, Tom (University College London (UCL)); Mulder, M. (TU Delft Human-Robot Interaction); de Winter, J.C.F. (TU Delft Biomechatronics & Human-Machine Control); Aminravan, Farzad (University of British Columbia); Gibo, T.L. (TU Delft Biomechatronics & Human-Machine Control); Boer, E.R. (TU Delft Human-Robot Interaction)","","2018","Shared control is an increasingly popular approach to facilitate control and communication between humans and intelligent machines. However, there is little consensus in guidelines for design and evaluation of shared control, or even in a definition of what constitutes shared control. This lack of consensus complicates cross fertilization of shared control research between different application domains. This paper provides a definition for shared control in context with previous definitions, and a set of general axioms for design and evaluation of shared control solutions. The utility of the definition and axioms are demonstrated by applying them to four application domains: automotive, robot-assisted surgery, brain–machine interfaces, and learning. Literature is discussed for each of these four domains in light of the proposed definition and axioms. Finally, to facilitate design choices for other applications, we propose a hierarchical framework for shared control that links the shared control literature with traded control, co-operative control, and other human–automation interaction methods. Future work should reveal the generalizability and utility of the proposed shared control framework in designing useful, safe, and comfortable interaction between humans and intelligent machines.","Automation; Automotive engineering; Control systems; Human-automation interaction; machine interaction; robot interaction (HRI); Mobile robots; Robot sensing systems; shared control; supervisory control; Task analysis; traded control cooperation","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-11-01","","","Human-Robot Interaction","","",""
"uuid:81480599-be45-4bd2-ab41-3a14a559e7ca","http://resolver.tudelft.nl/uuid:81480599-be45-4bd2-ab41-3a14a559e7ca","Effects of Preview Time in Manual Tracking Tasks","van der El, Kasper (TU Delft Control & Simulation); Padmos, S. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2018","In manual control tasks, preview of the target trajectory ahead is often limited by poor lighting, objects, or display edges. This paper investigates the effects of limited preview, or preview time, in manual tracking tasks with single- and double-integrator controlled element dynamics. A quasi-linear human controller model is used to predict the human behavior adaptations offline, by finding the model parameters that yield optimal performance at each preview time. These predictions are then verified by fitting the same model to measurements from a human-in-the-loop experiment, where subjects performed a tracking task with eight different preview time settings between 0 and 2 s. Results show that the tracking performance improves and the model’s “look-ahead” time parameters increase with increasing preview time. Beyond a certain preview time, approximately 0.6 s and 1.15 s in single- and double-integrator tasks, respectively, additional preview evokes no further adaptations. The offline model predictions closely match the experimental results, which thereby promises to facilitate similar quantitative insights in other tasks with restricted preview.","Adaptation models; Data models; Manual control; Manuals; modeling; parameter estimation; Predictive models; preview time; system identification; Target tracking; Task analysis; Trajectory","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:4a5959d9-7d2b-4d17-b99b-2b452cb75816","http://resolver.tudelft.nl/uuid:4a5959d9-7d2b-4d17-b99b-2b452cb75816","Rethinking Design: A critical perspective to embrace societal challenges","Mulder, I. (TU Delft Design Conceptualization and Communication); Loorbach, Derk (Erasmus Universiteit Rotterdam)","Kossoff, G. (editor); Potts, R. (editor)","2018","","","en","conference paper","Carnegie Mellon University","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:13ddbcf5-ad1b-406b-944d-00b884905c4e","http://resolver.tudelft.nl/uuid:13ddbcf5-ad1b-406b-944d-00b884905c4e","Empowering community volunteers through matchmaking services","Slingerland, G. (TU Delft System Engineering); Mulder, I. (TU Delft Design Conceptualization and Communication); Jaśkiewicz, T.J. (TU Delft Design Conceptualization and Communication)","Meroni, A. (editor); Medina, A.M.O. (editor); Villari, B. (editor)","2018","In Rotterdam, the participatory turn has spurred various bottom-up communities around public parks. These communities aim to take care of the parks in their neighbourhood and search for ways to demonstrate the societal value of their initiative. The current work explores how digital matchmaking services can strengthen community relationships. A research-through-design approach is applied to identify the main barriers hindering community participation. The final design Park Makers uses both Citizen-to-Activity matching and Citizen-to-Citizen matching as ways to engage citizens in the community. The corresponding research demonstrates that connecting park users (or better: future volunteers) with another citizen or activity matching their personal interest fosters community engagement. From this point of view, it might be interesting to focus further research on the potential value of other matchmaking principles, or even other services, for bottom-up citizen communities.","citizen participation; community engagement; public parks; service design; social cohesion","en","conference paper","Linköping University Electronic Press","","","","","","","","","","System Engineering","","",""
"uuid:7a3fe23a-0d7d-4d02-bca6-072486f30afb","http://resolver.tudelft.nl/uuid:7a3fe23a-0d7d-4d02-bca6-072486f30afb","Data Exploration for Generative Design Research","Kun, P. (TU Delft Design Conceptualization and Communication); Mulder, I. (TU Delft Design Conceptualization and Communication); Kortuem, G.W. (TU Delft Internet of Things)","Storni, C. (editor); Leahy, K. (editor); McMahon, M. (editor); Lloyd, P. (editor); Bohemia, E. (editor)","2018","The current work elaborates upon a Generative Data Exploration method, which is a design technique aiming at supporting designers in integrating data in their design activities. Digital data offers new opportunities in all sort of professional domains, yet existing approaches and tools to manipulate data are predominantly targeted at data experts. As access to data is becoming democratised, new types of techniques are needed to leverage the agency of designers and to empower them to utilise data in the design process. Designers without prior data experience can benefit from the techniques, know-how, best practices of experts, if such expert knowledge is codified in design methods and tools. The aims of a Generative Data Exploration method are two-fold. First, the method facilitates a learning curve on gaining holistic data literacy.
Second, the method supports designing where digital data, exploration of data and sense-making of data is part of the process.","design methods; data exploration; generative design; fuzzy front-end","en","conference paper","Design Research Society","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:6d3b11a8-e0de-402d-9020-547b57702eb3","http://resolver.tudelft.nl/uuid:6d3b11a8-e0de-402d-9020-547b57702eb3","New higher-order mass-lumped tetrahedral elements for wave propagation modelling","Geevers, S. (University of Twente); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); van der Vegt, J. J.W. (University of Twente)","","2018","We present a new accuracy condition for the construction of continuous mass-lumped elements. This condition is less restrictive than the one currently used and enabled us to construct new mass-lumped tetrahedral elements of degrees 2 to 4. The new degree-2 and degree-3 tetrahedral elements require 15 and 32 nodes per element, respectively, while currently, these elements require 23 and 50 nodes, respectively. The new degree-4 elements require 60, 61, or 65 nodes per element. Tetrahedral elements of this degree had not been found until now. We prove that our accuracy condition results in a mass-lumped finite element method that converges with optimal order in the $L^2$-norm and energy-norm. A dispersion analysis and several numerical tests confirm that our elements maintain the optimal order of accuracy and show that the new mass-lumped tetrahedral elements are more efficient than the current ones.
the first-order form has short-wavelength null-vectors. Once excited, these modes are not seen by the spatial operator but only by the time- stepping scheme and show up as noise. A sourcewith a larger spatial extent, for instance a Gaussian or a tapered sinc, can avoid the excitation of problematic short wavelengths. A series of numerical experiments on a 2-D problem with an exact solution provides a suggestion for the best choice of parameters for these source
term distributions. The tapered sinc provided the best results and the resulting accuracy can be better than that of the second-order form. The higher operation count of the former, however, does not make it more efficient in terms of accuracy for a given computational effort, at least not for the 2-D examples considered here","","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:7cc16226-c6e5-4b4a-8e78-9f767013d37e","http://resolver.tudelft.nl/uuid:7cc16226-c6e5-4b4a-8e78-9f767013d37e","Leveraging prototypes to Support Self-directed Social learning in Makerspaces","Jaśkiewicz, T.J. (TU Delft Design Conceptualization and Communication); Mulder, I. (TU Delft Design Conceptualization and Communication); Verburg, Samuel (Student TU Delft); Verheij, Bob (Student TU Delft)","Bohemia, E. (editor); Kovacevic, A. (editor); Buck, L. (editor); Childs, P. (editor); Green, S. (editor); Hall, A. (editor); Dasan, A. (editor)","2018","The “Maker Movement” signifies emergence of a cultural model of a society where anyone can become a creative maker. As part of this movement, various kinds of “Makerspaces” provide physical and social infrastructures that help unleash people’s intrinsic abilities to make, create, and innovate. In this way, makerspaces become loci where maker communities develop as communities of interest and communities of practice. In such communities, participants acquire skills and knowledge through selfdirected peer-learning and learning-by-doing, while leveraging each other’s practical expertise, individual motivations and enthusiasm. The presented work elaborates upon how maker communities
within academic design engineering education and everyday-life contexts could better support their participants’ self-directed learning. Throughout two independent researches through design case studies, we investigated how these learning processes could be improved. Both cases involved the iterative development and assessment of service platforms for supporting the social learning processes of makers. One platform focused on documenting and sharing skills of makers, the other on documenting and sharing the making processes leading to a given artefact. Reflecting on the two platforms revealed two distinct aspects of encountered learning. The first aspect involves deepening
and mutually encouraging development of individual expert skills. The second aspect involves multidisciplinary alignment during collaborations and peer-learning within a maker community, performed in teams encompassing complementary skills. The lessons learnt lead to proposing a conceptual framework, which aims to provide a support structure to improve self-directed social learning processes in makerspaces.","Learning-by-Making; Makerspaces; Peer-learning; Prototyping; Research-through-Design","en","conference paper","The Design Society","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:ad3cfafe-2569-4546-b6dd-32ddcaf5e17c","http://resolver.tudelft.nl/uuid:ad3cfafe-2569-4546-b6dd-32ddcaf5e17c","Effects of Preview on Human Control Behavior in Tracking Tasks With Various Controlled Elements","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","This paper investigates how humans use a previewed target trajectory for control in tracking tasks with various controlled element dynamics. The human's hypothesized ""near"" and ""far"" control mechanisms are first analyzed offline in simulations with a quasi-linear model. Second, human control behavior is quantified by fitting the same model to measurements from a human-in-the-loop experiment, where subjects tracked identical target trajectories with a pursuit and a preview display, each with gain, single-, and double-integrator controlled element dynamics. Results show that target-tracking performance improves with preview, primarily due to the far-viewpoint response, which allows humans to cancel their own and the controlled element's lags, without additional control activity. The near-viewpoint response yields better target tracking at higher frequencies, but requires substantially more control activity. The control-theoretic approach adopted in this paper provides unique quantitative insights into human use of preview, which can help to explain human behavior observed in other preview control tasks, like driving.","","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:d465584a-e935-46b0-a2a5-db192c182231","http://resolver.tudelft.nl/uuid:d465584a-e935-46b0-a2a5-db192c182231","Effects of Linear Perspective on Human Use of Preview in Manual Control","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2018","Due to linear perspective, the visual stimulus provided by a previewed reference trajectory reduces with increasing distance ahead. This paper investigates the effects of linear perspective on human use of preview in manual control tasks. Results of a human-in-the-loop tracking experiment are presented, where the linear perspective's horizontal and vertical deformations along the previewed trajectory were applied separately and combined, or were absent (plan-view task). Measurements are analyzed with both nonparametric and parametric system identification techniques, in combination with a quasi-linear human controller model for plan-view preview tracking tasks. Results show that reduced visual stimuli in perspective tasks evoke less aggressive control behavior, but that the human's underlying control mechanisms are still accurately captured by the model. We conclude that human controllers use preview information similar in plan-view and perspective tasks.","Adaptation models; Analytical models; Human factors; Linear perspective; man–machine systems; Man-machine systems; manual control; parameter estimation; preview; system identification; Target tracking; Trajectory; Visualization","en","journal article","","","","","","","","","","","Control & Simulation","","",""
"uuid:5fae23aa-d79a-4863-911d-c296cc0f6baf","http://resolver.tudelft.nl/uuid:5fae23aa-d79a-4863-911d-c296cc0f6baf","Higher-order source-wavefield reconstruction for reverse time migration from stored values in a boundary strip just one point wide","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2018","One way to deal with the storage problem for the forward source wavefield in reverse time migration and full-waveform inversion is the reconstruction of that wavefield during reverse time stepping along with the receiver wavefield. Apart from the final states of the source wavefield, this requires a strip of boundary values for the whole time range in the presence of absorbing boundaries. The width of the stored boundary strip, positioned in between the interior domain of interest and the absorbing boundary region, usually equals about half that of the finite-difference stencil. The required storage in 3D with high frequencies can still lead to a decrease in computational efficiency, despite the substantial reduction in data volume compared with storing the source wavefields at all or at appropriately subsampled time steps. We have developed a method that requires a boundary strip with a width of just one point and has a negligible loss of accuracy. Stored boundary values over time enable the computation of the second and higher even spatial derivatives normal to the boundary, which together with extrapolation from the interior provides stability and accuracy. Numerical tests show that the use of only the boundary values provides at most fourth-order accuracy for the reconstruction error in the sourcewavefield. The use of higher even normal derivatives, reconstructed from the stored boundary values, allows for higher orders as numerical examples up to order 26 demonstrate. Subsampling in time is feasible with highorder interpolation and provides even more storage reduction but at a higher computational cost.","","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:89fc1ed9-294b-4b12-ba82-127a4ce07e6f","http://resolver.tudelft.nl/uuid:89fc1ed9-294b-4b12-ba82-127a4ce07e6f","A Cybernetic Analysis of Biodynamic Effects in Touchscreen Operation in Turbulence","Mobertz, Xander; Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","This paper describes a human-in-the-loop experiment performed in TU Delft’s SIMONA Research Simulator to explicitly investigate the effects of biodynamic feedthrough (BDFT) on the execution of a two-dimensional touchscreen waypoint dragging task in turbulence. In the experiment, 16 participants performed the same task in a stationary simulator and whilst being perturbed in either surge, sway, or heave directions by the same motion disturbance signal. In addition, the effect of screen location on biodynamic effects was tested by considering two touchscreen display positions, i.e., representative for the Primary Flight Display (PFD) and the Control Display Unit (CDU), respectively. The collected results show significantly more issues with loss of screen contact for the PFD display, due to the extended arm position when operating this display. Despite the fact that small biodynamic effects are also found for off-axis disturbances, the results clearly show that issues with BDFT predominantly occur when motion disturbances are aligned with the touchscreen control input direction. Due to the use of a multisine motion disturbance signal in the experiment, explicit BDFT detection and identification was possible with spectral methods. For the conditions where sufficient BDFT was detected to allow for modeling the BDFT dynamics, a second-order BDFT model was proposed and found to explain at least 70% of the BDFT input components. With consistent BDFT model parameter estimates between conditions, this approach shows clear merit for quantitative analysis of biodynamic effects on touchscreen operation and potentially even for BDFT mitigation through model-based input cancellation.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","2019-02-01","","Control & Operations","Control & Simulation","","",""
"uuid:5fb751fa-8ee9-4ad8-ab76-e82ec3f6f5d6","http://resolver.tudelft.nl/uuid:5fb751fa-8ee9-4ad8-ab76-e82ec3f6f5d6","Design of a Haptic Feedback System for Flight Envelope Protection","van Baelen, D. (TU Delft Control & Simulation); Ellerbroek, Joost (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","Current Airbus aircraft use a fly-by-wire control device: a passive spring-damper system which generates, without any force feedback, an electrical signal to the flight control computer. Additionally, a hard flight envelope protection system is used which can limit the inputs of the pilot when approaching the edges of the flight envelope. To increase the situation awareness of the pilot, this research aims to provide intuitive information on the flight envelope through haptics, force feedback trough the control device, integrated in the existing Airbus control laws. The goal of this paper is to describe when and how haptics is used in this design. The pilot can get five cues of the flight envelope: when approaching the flight envelope a discrete force cue is given. Next, control inputs which move the aircraft closer to the flight envelope are indicated with an increased spring coefficient. Moving too close to the lower velocity limit activates a stick shaker: a vibration force on the stick. If a stick neutral position is not sufficient to return to the safe flight envelope, the stick is moved forward to the desired control input. Finally, following the automatic Airbus pitch up command during an overspeed condition, the stick is moved back to follow this command. This new system is expected to help identifying the situation and choosing a possible mitigation technique which is evaluated for two scenarios: when the aircraft is moving to the flight envelope, i.e. a windshear, or when the flight envelope moves towards the aircraft.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","2019-02-01","","Control & Operations","Control & Simulation","","",""
"uuid:2a21c80a-a674-497e-acb3-c65fb439a421","http://resolver.tudelft.nl/uuid:2a21c80a-a674-497e-acb3-c65fb439a421","Design and Evaluation of a Haptic Aid for Training of the Manual Flare Manoeuvre","Deldycke, Pieter-Jan; van Baelen, D. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2018","The use of haptic feedback as a tool for skill training has shown benefits for the formation ofmotor-memory and support for certain temporal tasks. Therefore, this research focuses on the development of a haptic aid for supporting the training of the challenging manual flare maneuver in initial pilot training. The haptic aid, which consisted of three “off-target” haptic modes each meant to clarify a typical mistake in flare execution, was designed based on instructor actions during real flight training. The High Roundout (HR) mode was designed to better train flare timing. This haptic mode implemented an increase in pitch-up stick stiffness when still above the desired flare altitude. The Late Roundout (LR) and Ballooning (BA) modes used repeated pulses on the stick – in pitch-up and pitch-down directions, respectively – to alert trainees when they flared too late (or not at all) or when overly large pitch-up inputs that would lead to regaining altitude were given. To test the haptic aid, a quasi-transfer-of-training experiment with 16 novices was performed in a full-motion research simulator. A baseline group and a group receiving haptic feedback were compared and in the haptics group the haptic aid was used during the training phase of the experiment, but disabled in the evaluation phase. A second-stage evaluation, with an untrained landing scenario, was used to verify the generalizability of the skills. The obtained data indicates no improved learning effect regarding flare trajectory. It was found that due to the difficulty of the task, strategies based on linking the cues to desired discrete touchdown performance were formed. The usage of the HR mode, however, resulted in more consistent initiation of the flare which was retained after transfer. The second-stage evaluation also did not show worsening of flare performance, suggesting generalizability of the skills with the haptic aid.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","2019-02-01","","Control & Operations","Control & Simulation","","",""
"uuid:7aa392f4-899f-4010-88b5-39c14c78881b","http://resolver.tudelft.nl/uuid:7aa392f4-899f-4010-88b5-39c14c78881b","Identification of Time-Varying Manual-Control Adaptations with Recursive ARX Models","van Grootheest, Andries; Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","Time-varying human-operator (HO) adaptation in basic manual-control tasks is barely understood, as most HO identification methods do not explicitly take into account time variations. An identification procedure based on both batch and recursive autoregressive exogenous (ARX) models is used in this paper for captur- ing HO adaptation to time-varying changes in controlled-element dynamics in compensatory tracking tasks. Conditions with constant controlled-element dynamics, matching recent experimental work, and gradual and sudden transitions in the controlled-element dynamics were compared by means of Monte Carlo simulations with different remnant noise intensities. Overall, with batch ARX model identification results for conditions with constant dynamics, it is shown that differences between remnant noise and HO dynamics, both of which are directly coupled in the ARX model structure, will bias the identified ARX model parameters. Nevertheless, recursive ARX model identification results were still found to provide a reasonably estimate of time-varying HO model parameters for the tested time-varying scenarios. A direct comparison of using a constant scalar forgetting factor and a constant forgetting matrix, containing separate forgetting factors for each ARX model parameter, showed that a forgetting matrix did not result in a significant improvement for the considered HO identification problem. A forgetting factor of = 0.99609, corresponding to a memory horizon of 256 samples at 100 Hz, is found to be optimal for all tested conditions. An evaluation of real experimental manual-control data shows that, with straightforward online implementation, the method has potential as a tool for investigating, modeling, and measuring operators’ adaptive control characteristics.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","2019-02-01","","Control & Operations","Control & Simulation","","",""
"uuid:67df6464-fbd1-4186-872c-9401d26a8283","http://resolver.tudelft.nl/uuid:67df6464-fbd1-4186-872c-9401d26a8283","Robots and us: towards an economics of the ‘Good Life’","Naastepad, C.W.M. (TU Delft Economics of Technology and Innovation); Mulder, Jesse M. (Universiteit Utrecht)","","2018","(Expected) adverse effects of the ‘ICT Revolution’ on work and opportunities for individuals to use and develop their capacities give a new impetus to the debate on the societal implications of technology and raise questions regarding the ‘responsibility’ of research and innovation (RRI) and the possibility of achieving ‘inclusive and sustainable society’. However, missing in this debate is an examination of a possible conflict between the quest for ‘inclusive and sustainable society’ and conventional economic principles guiding capital allocation (including the funding of research and innovation). We propose that such conflict can be resolved by re-examining the nature and purpose of capital, and by recognising mainstream economics’ utilitarian foundations as an unduly restrictive subset of a wider Aristotelian understanding of choice.","Philosophical foundations of economics; homo economicus; responsible research and innovation (RRI); capital; productivity growth; ICT; IT; Aristotle; golden mean; inclusive society; telos; technological unemployment","en","journal article","","","","","","","","","","","Economics of Technology and Innovation","","",""
"uuid:3794a461-8fa2-4780-8650-855467f6c846","http://resolver.tudelft.nl/uuid:3794a461-8fa2-4780-8650-855467f6c846","Perception Centered Transparency Evaluation of Wave-variable based Bilateral Teleoperation","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","O’Conner, Lisa (editor)","2018","Wave-variable transformation is a means to maintain stability of haptic teleoperation in the presence of communication time delays. Its drawback is that it affects haptic perception of remote properties and thereby degrades transparency. This paper studies the effect of wave-variable transformation on human haptic perception. Based on a framework of haptic perception developed in previous work, we systematically investigated how the wave variable affects human perception of damping, mass and stiffness properties of an arbitrary linear environment. Both the original wave-variable approach and the generalized wave-variable approach are investigated. Results show how both approaches change human perception of all three mechanical properties of the environment, and how these changes vary with both excitation frequency and time delay. The generalized wave-variable approach on the whole outperforms the original in terms of rendering mass and stiffness, but not always for rendering damping. Results also show that human perception of the dynamics rendered by both approaches is similar to that of the original environment only when time delays are small. As the time delay increases, evaluating the mechanical properties can become very difficult for a human operator if the interaction with the environment is not static.","Teleoperation; Transparency; Wave variable; Haptic perception; Mechanical properties","en","conference paper","IEEE","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:89e20e80-af13-46bf-9525-750f634c1035","http://resolver.tudelft.nl/uuid:89e20e80-af13-46bf-9525-750f634c1035","Relating Human Gaze and Manual Control Behavior in Preview Tracking Tasks with Spatial Occlusion","Rezunenko, Evgeny (Student TU Delft); van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2018","In manual tracking tasks with preview of the target trajectory, humans have been modeled as dual-mode “near” and “far” viewpoint controllers. This paper investigates the physical basis of these two control mechanisms, and studies whether estimated viewpoint positions represent those parts of the previewed trajectory which humans use for control. A combination of human gaze and control data is obtained, through an experiment which compared tracking with full preview (1.5 s), occluded preview, and no preview. System identification is applied to estimate the two look-ahead time parameters of a two-viewpoint preview model. Results show that humans focus their gaze often around the model’s near-viewpoint position, and seldom at the far viewpoint. Gaze measurements may augment control data for the online identification of preview control behavior, to improve personalized monitoring or shared-control systems in vehicles.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:8ec3edf4-56a4-47e6-99ae-846358bb132c","http://resolver.tudelft.nl/uuid:8ec3edf4-56a4-47e6-99ae-846358bb132c","Energy Transition in Existing Districts in The Hague, a Bottom up Approach","Zoller, Fred; Mulder, K.F. (TU Delft Organisation & Governance)","","2018","","","en","conference paper","","","","","","","","","","","Organisation & Governance","","",""
"uuid:fc4bff7c-a633-4857-90c2-6b2ff29d98d7","http://resolver.tudelft.nl/uuid:fc4bff7c-a633-4857-90c2-6b2ff29d98d7","Niet zonder conflicten","Mulder, K.F. (TU Delft Organisation & Governance)","","2018","Duurzame ontwikkeling in het ingenieursonderwijs blijkt geen snelle conflictloze strategie voor verduurzaming. Met als gevolg dat het breder leren denken van de ingenieur in opleiding nog in de kinderschoenen staat.","","nl","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-04-01","","","Organisation & Governance","","",""
"uuid:295ab7f8-338a-4fa5-a1f0-960c02e98e91","http://resolver.tudelft.nl/uuid:295ab7f8-338a-4fa5-a1f0-960c02e98e91","Increasing Acceptance of Haptic Feedback in UAV Teleoperations by Visualizing Force Fields","Ho, V. (Student TU Delft); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","Haptic interfaces have been developed to assist human operators controlling unmanned aerial vehicles (UAV) be- yond line-of-sight. These systems complement the predominantly camera-based visual interfaces and act like a collision-avoidance system: when nearing obstacles, the operator gets re-directed by the haptic force feedback. Previous research showed that, although being successful in reducing the number of collisions, these haptic interfaces also lead to lower user acceptance, as the operators do not always understand the system’s intentions. This paper discusses two novel visualizations which were developed to increase operator acceptance. Both designs were evaluated in a human-in-the-loop experiment (n=12). Results from acceptance- related questionnaires show that our subjects preferred tele- operating the UAV with the visualizations active. Acceptance ratings were higher for the same levels of safety, performance and operator workload.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:9d2fac79-0b75-4f73-974c-89d6b2b902d9","http://resolver.tudelft.nl/uuid:9d2fac79-0b75-4f73-974c-89d6b2b902d9","Modeling the Coupled Difference Threshold of Perceiving Mass and Stiffness from Force","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","O’Conner, Lisa (editor)","2018","Abstract—Just notable difference (JND) thresholds for the perception of manipulator dynamic properties are relevant for tele-operation and simulation of vehicles. Manipulator dynamic properties are characterized by multiple variables (describing mass, spring and damping for a linear manipulator) and the JND threshold for any of these variables is affected by variation in the remaining variables. In previous work, we demonstrated and modeled the coupling of the stiffness JND and the mass JND, and investigated the effects of stiffness and mass properties on the damping JND. In this work we investigate how changes in the damping parameter affect the JND in perceiving stiffness and mass. In an experiment our subjects were instructed to discriminate between different levels of manipulator’s stiffness or mass, while tracking a prescribed sinusoidal manipulator movement. Results show that the JND in spring force and the JND in inertia force are identical, and increase for higher damping levels. The JND model developed in our previous work can successfully describe the experimental observations, thereby providing an extension of Weber’s law. The impedance of the manipulator is considered as the reference stimulus in the frequency domain, so that a single ratio describes the JND thresholds for all three properties. Index Terms—Just noticeable difference, Mass-spring-damper systems, Frequency response function, Weber’s law, haptics","Just noticeable difference; Mass-spring-damper systems; Frequency response function; Weber’s law; haptics","en","conference paper","IEEE","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:24df98e9-42e7-4915-a500-a53c27c9da2d","http://resolver.tudelft.nl/uuid:24df98e9-42e7-4915-a500-a53c27c9da2d","Identification and Modeling of Driver Multiloop Feedback and Preview Steering Control","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","Novel (semi-)automated systems are rapidly being introduced into modern road vehicles, but anticipating possibly critical human-machine interaction issues is difficult, because the human driver’s behavior is as of yet still poorly understood. This paper aims to improve our understanding and models of driver steering behavior on winding roads, using Frequency-Response Function (FRF) measurements of drivers’ feedforward, heading feedback, and lateral position feedback dynamics. The steering behavior data were collected in a human-in-the-loop simulator experiment, in which drivers followed the road centerline at constant forward velocity, while being perturbed laterally by wind-gust disturbances. All three measured FRFs can be captured with a multiloop, single preview-point driver model, which has only five parameters. These parameters provide unmatched understanding of – otherwise lumped – driver internal steering processes, quantifying how and what portion of the previewed centerline trajectory is used for control, and how lateral position and heading feedback are weighed. The gained insights may help to reduce driver-automation interaction issues in modern road vehicles, to quantify between-driver steering variations, adaptation and learning, and to design human-like and individualized automatic and shared steering controllers.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:671702cc-bd11-4548-827f-abe113f37826","http://resolver.tudelft.nl/uuid:671702cc-bd11-4548-827f-abe113f37826","A perceptually inspired Driver Model for Speed Control in curves","Gruppelaar, V. (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); Abbink, D.A. (TU Delft Human-Robot Interaction)","","2018","Understanding speed control in driving is important for analysis of road geometry and for the development of driver support assistance devices. Current models for speed selection are primarily based on the relation between road geometry and observed speeds. This study proposes a more detailed model that relates individual speed control to accelerator and brake pedal, based on perception of the visual scene as captured by the Extended Tangent Point (ETP). We investigated the potential of the the Time to ETP (TETP) as input for accelerator and brake pedal control. Based on observations from driving studies, we propose a model, and tuning rules to adjust the model parameters to observed behavior. A simulator experiment showed that, after individualization of the thresholds using a binary classification method, the model is capable of accurately capturing individual speed adaptation of 15 drivers on single lane roads with multiple curves.","","en","conference paper","IEEE","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:82f8ffbf-96d7-42d4-9cee-ade5676f90c4","http://resolver.tudelft.nl/uuid:82f8ffbf-96d7-42d4-9cee-ade5676f90c4","Co-creative partnerships as catalysts for social change","Mulder, I. (TU Delft Design Conceptualization and Communication)","","2018","Mundane cities are challenged to design for unpredictable and rapidly changing futures. In the current work, we refer to thesechallenges as a collaborative design challenge and explore how co-creative partnerships can enable a participatory turn by establishinga new social infrastructure. The corresponding citizen-centred design approach offers a variety of design opportunitiesto engage with citizens, to empower all involvement, and enabling a social fabric to be increasingly reflexive and responsive.Through the illustration of three collaborative design studies in the public realm, we explore how design can act as a strategytowards a transforming society. It shows that participatory designing enabled empowerment across the co-creative partnership,though it also calls for strategic guidance in order to sustain transformational change. We end with an elaborate discussion onthe role of strategic design in facilitating the interplay among new coalitions of city makers towards a transforming society thatembraces sustainable social innovation. It can be concluded that co-creative partnerships can act as network designers, capacitybuilders, and enablers of transformational change, and have the potential to act as change makers, driving sustainable socialinnovation.","co-creative partnerships; diffuse design; participation; social innovation; transitions","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:42f31d3a-d18b-41b9-9b09-bf1c0643a96c","http://resolver.tudelft.nl/uuid:42f31d3a-d18b-41b9-9b09-bf1c0643a96c","Using Augmented Reality to Improve Collision Avoidance and Resolution","Procee, S. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","Bertram, Volker (editor)","2018","Based on the Cognitive Work Analysis, described in a previous paper, an Ecological Interface is designed and built for the Augmented Reality application at Willem Barentsz. Incorporated, a.o., is the concept of Velocity Obstacles. This innovative way to visualize the problem space and solution space, provides the navigator with real time information about the possible combinations of course and speed that avoid intrusion into an other ship’s protected zone. Hence, it is anticipated that this will result in better Situation Awareness, leading to less close encounters, a.k.a. near misses, and fewer collisions.","","en","conference paper","Technische Universität Hamburg-Harburg","","","","","","","","","","Control & Simulation","","",""
"uuid:e7a11851-6f5b-4035-9308-e41da8a27b9c","http://resolver.tudelft.nl/uuid:e7a11851-6f5b-4035-9308-e41da8a27b9c","Haptic Support for Aircraft Approaches with a Perspective Flight-path Display","Beeftink, Derek G. (Student TU Delft); Borst, C. (TU Delft Control & Simulation); van Baelen, D. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2018","Perspective flight-path displays are a viable alternative for the aircraft primary flight display, but increases the pilot head-down time. A haptic interface is developed to counter this effect and increase the task-sharing performance during approach. An experiment (n=12) was conducted to test the effects of the haptic design on primary task performance with a tunnel-in-the-sky display, in a low and high workload condition. To investigate the effects of the haptic interface on the headdown time, a secondary task was presented on the simulator outside visual, in the form of bucket-shaped figures, requiring participants to indicate the direction of the one divergent figure. Secondary task performance was measured by success rate, average time to answer correctly and – by means of eye-tracker measurements – head-up time and number of gaze switches. Pilots also provided a subjective measure of their mental effort after each run. Results show that haptic feedback significantly increases both primary and secondary task performance of the pilots, especially when the primary task is more challenging. Workload ratings are significantly lower, and head-up time increases with haptic feedback.","Just noticeable difference; Mass-spring-damper systems; Frequency response function; Weber’s law; haptics","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:4ab54329-692a-4e36-88d0-579c12b41285","http://resolver.tudelft.nl/uuid:4ab54329-692a-4e36-88d0-579c12b41285","New Continuous Mass-lumped Finite Elements for 3D Wave Propagation","Geevers, S. (University of Twente); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell); van der Vegt, J.J.W. (University of Twente)","","2018","Spectral elements with mass lumping allow for explicit time stepping and are therefore attractive for modelling seismic wave propagation. Their formulation on rectangular elements is straighforward, but for tetrahedra only elements up to degree 3 are known. To preserve accuracy after mass lumping, these elements require additional nodes that make them computationally more expensive. Here, we propose a new, less restrictive accuracy condition for the construction of these continuous mass-lumped elements. This enables us to construct several new tetrahedral elements. The new degree-2 and degree-3 elements require 15 and 32 nodes, while the existing ones have 23 and 50 nodes per element, respectively. We also developed degree-4 tetrahedral elements with 60, 61, or 65 nodes per element. Numerical examples confirm that the various mass-lumped elements maintain the optimal order of accuracy and show that the new elements are significantly more efficient in terms of accuracy versus compute time than the existing ones.","","en","conference paper","","","","","","","","2019-01-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:d929d485-959a-4733-8d9b-a8da26bb42c9","http://resolver.tudelft.nl/uuid:d929d485-959a-4733-8d9b-a8da26bb42c9","Effectiveness of a Computer-Based Helicopter Trainer for Initial Hover Training","Scaramuzzino, Paolo Francesco (TU Delft Control & Simulation; Politecnico di Milano); D’Intino, Giulia (Max Planck Institute for Biological Cybernetics; University of Pisa); Geluardi, Stefano (Max Planck Institute for Biological Cybernetics); Pavel, M.D. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation); Bülthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics)","Hermans, C. (editor)","2018","Today, simulators are achieving levels of complexity and cost that are comparable to those of the aircraft they should replace. For this reason, questions have been raised, in both the technical and training communities, on the required level of simulation 1delity for effective pilot training. Computer Based Trainers (CBTs) are not currently considered in regulatory standards, because it has not been proven yet whether they can replace or complement actual 2ight training hours. The aim of this paper is to better understand to what extent the low-level hover skills developed on a CBT are effectively transferred to a more realistic simulation environment. To achieve this goal, a quasi-Transfer-of-Training (qToT) experiment with task-naïve participants was performed in the CyberMotion Simulator (CMS) at the Max Planck Institute for Biological Cybernetics. Twenty-four subjects, divided in two groups, were trained to perform the hover maneuver controlling an identi1ed model of a Robinson R44 civil light helicopter. The 1rst group (the “experimental” group) was trained in a CBT and then transferred to the realistic setting in the CMS. The second group (the “control” group) received the entire training in the CMS. At the end of the experiment, the two groups were found to show comparable performance. This suggests that, even for the training of low-level 2ying skills, CBTs may be a valid alternative to high 1delity simulators, if supported by a suitable training program.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:19fcd84a-a31f-4302-a92e-c26bed99101f","http://resolver.tudelft.nl/uuid:19fcd84a-a31f-4302-a92e-c26bed99101f","Eigenmode Distortion as a Novel Criterion for Motion Cueing Fidelity in Rotorcraft Flight Simulation","Miletović, I. (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Wentink, Mark (Desdemona B.V.); Mulder, Max (TU Delft Control & Operations)","Hermans, C. (editor)","2018","Eigenmode distortion (EMD) is a novel methodology developed to study the degradation of perceived vehicle dynamics as a result of motion cueing algorithms (MCA’s) applied in rotorcraft 2ight simulators. This paper brie2y introduces EMD and subsequently describes its application in a pilot-in-the-loop experiment conducted on the SIMONA Research Simulator at Delft University of Technology. The experiment considers a precision hover task performed by two test pilots in three different motion cueing conditions. Each of the evaluated conditions is devised such to best reproduce one of the vehicle modes (pitch/heave subsidences and phugoid) simulated using an independently developed, three degree-of-freedom, longitudinal, nonlinear model of the AH-†„ Apache helicopter. The experiment yielded a number of interesting results. For example, the mode participation factors (MPFs) computed using recorded model states showed that the unstable phugoid mode dominates the overall dynamic response in all conditions evaluated. Also, based on the relative distribution of MPF’s across the three motion conditions, some indication of a change in pilot control behaviour as a result of motion cues (or lack thereof) was exposed. Finally, subjective pilot ratings suggest that the motion cueing condition optimized for the pitch subsidence mode is preferred, even though this is not the dominant mode in the vehicle’s response. The condition corresponding to the heave subsidence mode (i.e., only vertical motion cues) is appreciated least.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:a3faa8a7-8823-4394-9d51-108e32504b53","http://resolver.tudelft.nl/uuid:a3faa8a7-8823-4394-9d51-108e32504b53","Estimation of Nonlinear Contributions in Human Controller Frequency Response Functions","Wagenaar, S.E. (Student TU Delft); Pool, D.M. (TU Delft Control & Simulation); Damveld, H.J. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations; TU Delft Control & Simulation)","","2018","Traditional Frequency Response Function (FRF) estimation techniques used for analysis of Human Controller (HC) dynamics in tracking tasks assume HC dynamics to be linear, but generally do not quantify or compensate for the effects of human nonlinearities. The robust and fast Best Linear Approximation (BLA) techniques for estimating an FRF do provide such quantification of nonlinear distortions caused by Period-In-Same-Period-Out (PISPO) nonlinearities and can reduce the effect of PISPO nonlinear operations on the FRF estimate. This paper investigates the application of these BLA techniques to both measured and simulated HC data. For the simulated data, a linear HC model was deliberately extended with a symmetric PISPO deadzone nonlinear operator and a realistic level of HC “remnant” noise. Overall, both the measured and the simulated data indicate that due to the high levels of remnant noise inherent to HC data, no consistent estimate of PISPO nonlinear contributions could be made. This also means that the improvement of using BLA techniques and averaging over multiple forcing function realizations does not result in a substantial improvement over the current practice of estimating HC FRFs from repeated measurements of a single forcing function.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:24021697-2005-4f67-ba08-fc1504a88891","http://resolver.tudelft.nl/uuid:24021697-2005-4f67-ba08-fc1504a88891","Effects of Simulator Motion on Driver Steering Performance with Various Visual Degradations","Wolters, Joris P. M. A. (Student TU Delft); van der El, Kasper (TU Delft Control & Simulation); Damveld, H.J. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2018","This paper investigates the effects of simulator motion on driver steering performance, and how this depends on the available visual information and external disturbances such as wind gusts. A human-in-the-loop driving experiment was performed in which twelve participants steered a fixedvelocity car to follow a winding road (target tracking, TT) while suppressing side-wind gusts (disturbance-rejection, DR). Driver performance with and without motion feedback is compared in six tasks: “regular” lane-keeping with optic flow, centerline tracking with optic flow, and centerline tracking without optic flow, all with both 5 and 100 m of preview. Performance is calculated in the frequency domain to separate TT and DR contributions. The results show that motion feedback always yields improved DR performance, but the actual improvement depends strongly on the available simulator visuals. TT performance is generally unaffected by motion feedback, except when preview is limited. We conclude that simulator motion is required to evoke realistic driver performance in tasks where substantial external disturbances are present, but not in disturbance-free tasks where a winding road is being followed.","Terms—Driving; simulation; manual control; physical motion; simulator visuals; vehicle steering","en","conference paper","","","","","","","","","","","Control & Simulation","","",""
"uuid:ba917eb8-0d71-4c16-ac44-b6da67e47692","http://resolver.tudelft.nl/uuid:ba917eb8-0d71-4c16-ac44-b6da67e47692","Oriented Attachment and Nanorod Formation in Atomic Layer Deposition of TiO2 on Graphene Nanoplatelets","Grillo, F. (TU Delft ChemE/Product and Process Engineering); La Zara, D. (TU Delft ChemE/Product and Process Engineering); Mulder, P.C.M. (TU Delft Applied Sciences); Kreutzer, M.T. (TU Delft ChemE/Chemical Engineering); Ruud Van Ommen, J.","","2018","Understanding the spontaneous organization of atoms on well-defined surfaces promises to enable control over the shape and size of supported nanostructures. Atomic layer deposition (ALD) boasts atomic-scale control in the synthesis of thin films and nanoparticles. Yet, the possibility to control the shape of ALD-grown nanostructures remains mostly unexplored. Here, we report on the bottom-up formation of both linear and V-shaped anatase TiO2 nanorods (NRs) on graphene nanoplatelets during TiCl4/H2O ALD carried out at 300 °C. NRs as large as 200 nm form after only five ALD cycles, indicating that diffusional processes rather than layer-by-layer growth are behind the NR formation. In particular, high-resolution transmission electron microscopy reveals that the TiO2 NRs and graphene nanoplatelets are in rotational alignment as a result of lattice matching. Crucially, we also show that individual nanocrystals can undergo in-plane oriented attachment.","","en","journal article","","","","","","","","","Applied Sciences","ChemE/Chemical Engineering","ChemE/Product and Process Engineering","","",""
"uuid:226374a4-954e-4c46-90eb-154ef20ae6aa","http://resolver.tudelft.nl/uuid:226374a4-954e-4c46-90eb-154ef20ae6aa","Honeycomb-like porous 3D nickel electrodeposition for stable Li and Na metal anodes","Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Sreekumar Menon, A. (TU Delft ChemE/Materials for Energy Conversion and Storage; TNO); Harks, P.P.R.M.L. (TU Delft ChemE/Materials for Energy Conversion and Storage); Hermes, Dorothee C. (TNO); Haverkate, Lucas A. (TNO); Unnikrishnan, Sandeep (TNO); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2018","Li and Na metals have the highest theoretical anode capacity for Li/Na batteries, but the operational safety hazards stemming from uncontrolled growth of Li/Na dendrites and unstable electrode-electrolyte interfaces hinder their real-world applications. Recently, the emergence of 3D conductive scaffolds aimed at mitigating the dendritic growth to improve the cycling stability has gained traction. However, while achieving 3D scaffolds that are conducive to completely prevent dendritic Li/Na is challenging, the routes proposed to fabricate 3D scaffolds to date are often complex and expensive. This not only leads to sub-optimal battery performance but can make the manufacturing nearly unachievable, compromising their commercial viability. We herein introduce a facile and single-step route to honeycomb-like 3D porous Ni@Cu scaffolds via a hydrogen bubble dynamic template (HBDT) electrodeposition method. The current collectors fabricated by this method offer highly stable cycling performance of Li plating/stripping (>300 cycles at 0.5 mAh cm−2 and over 200 cycles at 1.0 mAh cm−2), attributed to their ability to effectively accommodate Li/Na deposits in their porous networks and to delocalize the charge distribution. The beneficial role of LiNO3 as an electrolyte additive in improving the mechanical integrity of solid electrolyte interface (SEI) and mechanistic insights into how the 3D porous structure facilitates Li/Na plating/stripping are comprehensively presented. Finally, with an outstanding cycling performance of reversible Na deposition (over 240, 110 and 50 cycles for 0.5, 1.0 and 2.0 mAh cm−2 at 1.0 mA cm−2), our findings open new doors to expedite the development of Li/Na metal battery technology.","3D nickel; Dendrite-free; Electrodeposition; Li/Na metal anode","en","journal article","","","","","","Accepted Author Manuscript","","2019-12-06","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:bba9de9d-9ccc-4e0e-9f19-569bb9413ab3","http://resolver.tudelft.nl/uuid:bba9de9d-9ccc-4e0e-9f19-569bb9413ab3","TiF3 catalyzed MgH2 as a Li/Na ion battery anode","Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2018","MgH2 has been considered as a potential anode material for Li ion batteries due to its low cost and high theoretical capacity. However, it suffers from low electronic conductivity and slow kinetics for hydrogen sorption at room temperature that results in poor reversibility, cycling stability and rate capability for Li ion storage. This work presents a MgH2–TiF3@CNT based Li ion battery anode manufactured via a conventional slurry based method. Working with a liquid electrolyte at room temperature, it achieves a high capacity retention of 543 mAh g−1 in 70 cycles at 0.2 C and an improved rate capability, thanks to the improved hydrogen sorption kinetics with the presence of catalytic TiF3. Meanwhile, the first realization of Na ion uptake in MgH2 has been evidenced in experiments.","Li ion battery; MgH; Na ion battery; TiF","en","journal article","","","","","","Accepted Author Manuscript","","2020-10-04","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:f6b45caf-b69b-4531-9b64-5ae14bdeadce","http://resolver.tudelft.nl/uuid:f6b45caf-b69b-4531-9b64-5ae14bdeadce","Nitros: An innovative training program to enhance rotorcraft safety","Quaranta, Giuseppe (Politecnico di Milano); Pavel, M.D. (TU Delft Control & Simulation); Barakos, George (University of Glasgow); White, Mark (University of Liverpool); Mulder, Max (TU Delft Control & Simulation)","","2018","Helicopters are currently used in important applications providing a valuable contribution to society and economic growth. Thanks to their operational flexibility it is possible to accomplish increasingly complex missions. If the expansion of the usage of rotorcraft is to follow the pace of growth achieved by the fixed-wing public transport in the last years, several issues need to be urgently addressed to increase the use and the public acceptance of rotorcraft. Aspects related to complexity of the operations and safety are of primary importance, since in the last 20 years helicopter accident rates, worldwide, remained unacceptably high, when compared to fixed-wing aircraft. The complexity of the phenomena involved in rotorcraft flight calls for the training of engineers with a genuine multidisciplinary background. This paper presents the doctoral research and training program NITROS, which is set up under the Marie Skłodowska-Curie Action of the European Union to address complex solutions to rotorcraft safety.","","en","journal article","","","","","","","","2019-12-01","","","Control & Simulation","","",""
"uuid:73d09182-4075-495c-a632-8b6e46c3ed9e","http://resolver.tudelft.nl/uuid:73d09182-4075-495c-a632-8b6e46c3ed9e","Creating Circular, Efficient and Symbiotic Cities: And How Higher Education Should Contribute to Create the Solutions that are Required","Mulder, K.F. (TU Delft Organisation & Governance)","Leal Filho, Walter (editor)","2018","The ‘Grand Challenges’ of our times, like climate change, resource depletion, global inequity and the destruction of wildlife and biodiversity can only be addressed by innovating cities. This paper will analyse major options for innovating cities, main barriers for these innovations that are rooted in the paradigms of the experts running urban systems and educational reforms that might contribute overcoming these barriers.","","en","book chapter","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-04-04","","","Organisation & Governance","","",""
"uuid:a8bf5f67-14db-45e8-b243-cfafb63eb57e","http://resolver.tudelft.nl/uuid:a8bf5f67-14db-45e8-b243-cfafb63eb57e","Dealing With Unexpected Events on the Flight Deck: A Conceptual Model of Startle and Surprise","Landman, H.M. (TU Delft Control & Simulation); Groen, Eric L. (TNO); van Paassen, M.M. (TU Delft Control & Simulation); Bronkhorst, Adelbert W. (TNO); Mulder, Max (TU Delft Control & Operations)","","2017","Objective: A conceptual model is proposed in order to explain pilot performance in surprising and startling situations. Background: Today’s debate around loss of control following in-flight events and the implementation of upset prevention and recovery training has highlighted the importance of pilots’ ability to deal with unexpected events. Unexpected events, such as technical malfunctions or automation surprises, potentially induce a “startle factor” that may significantly impair performance. Method: Literature on surprise, startle, resilience, and decision making is reviewed, and findings are combined into a conceptual model. A number of recent flight incident and accident cases are then used to illustrate elements of the model. Results: Pilot perception and actions are conceptualized as being guided by “frames,” or mental knowledge structures that were previously learned. Performance issues in unexpected situations can often be traced back to insufficient adaptation of one’s frame to the situation. It is argued that such sensemaking or reframing processes are especially vulnerable to issues caused by startle or acute stress. Conclusion: Interventions should focus on (a) increasing the supply and quality of pilot frames (e.g., though practicing a variety of situations), (b) increasing pilot reframing skills (e.g., through the use of unpredictability in training scenarios), and (c) improving pilot metacognitive skills, so that inappropriate automatic responses to startle and surprise can be avoided. Application: The model can be used to explain pilot behavior in accident cases, to design experiments and training simulations, to teach pilots metacognitive skills, and to identify intervention methods.","aviation; mental models; pilot performance; resilience; training","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:659b6dde-99d7-4909-a4d7-58c35b867f92","http://resolver.tudelft.nl/uuid:659b6dde-99d7-4909-a4d7-58c35b867f92","The Influence of Surprise on Upset Recovery Performance in Airline Pilots","Landman, H.M. (TU Delft Control & Simulation; TNO); Groen, Eric L. (TNO); van Paassen, M.M. (TU Delft Control & Simulation); Bronkhorst, Adelbert (TNO); Mulder, Max (TU Delft Control & Operations)","","2017","Objective: The aim of this study was to test if performance of airline pilots, in performing an aerodynamic stall recovery procedure, decreases when they are surprised, compared to when they anticipate a stall event.
Background: New flight-safety regulations for commercial aviation recommend the introduction of surprise and startle in upset prevention and recovery training. This calls for more evidence on the effects of surprise on pilot performance, as well as methods to effectively induce surprise in training simulators.
Method: The study took place in a motion-base simulator with a poststall aerodynamic model. Using a within-subjects design, the recovery performance of 20 pilots was tested in 2 conditions: 1 anticipated condition, and 1 surprise condition. In addition to flight parameters, subjective and physiological data relating to surprise and startle were measured.
Results: Pilots had significantly more difficulties with adhering to the recovery procedure in the surprise condition compared to the anticipation condition. The subjective and physiological measures confirmed that the manipulation mainly increased surprise, and to a lesser extent also startle.
Conclusion: The results suggest that pilots have more difficulty in managing an upset situation (i.e., an aerodynamic stall) when this situation is presented unexpectedly, underlining that upset prevention and recovery training should include elements of surprise.","","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:88951b0d-8b6a-421d-a232-914a620a847e","http://resolver.tudelft.nl/uuid:88951b0d-8b6a-421d-a232-914a620a847e","Surface-wave inversion for a P-velocity profile with a constant depth gradient of the squared slowness","Ponomarenko, A. V. (St. Petersburg State University); Kashtan, B. M. (St. Petersburg State University); Troyan, V. N. (St. Petersburg State University); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2017","Surface waves are often used to estimate a near-surface shear-velocity profile. The inverse problem is solved for the locally one-dimensional problem of a set of homogeneous horizontal elastic layers. The result is a set of shear velocities, one for each layer. To obtain a P-wave velocity profile, the P-guided waves should be included in the inversion scheme. As an alternative to a multi-layered model, we consider a simple smooth acoustic constant-density velocity model, which has a negative constant vertical depth gradient of the squared P-wave slowness and is bounded by a free surface at the top and a homogeneous half-space at the bottom. The exact solution involves Airy functions and provides an analytical expression for the dispersion equation. If the vs/vp ratio is sufficiently small, the dispersion curves can be picked from the seismic data and inverted for the continuous P-wave velocity profile. The potential advantages of our model are its low computational cost and the fact that the result can serve as a smooth starting model for full-waveform inversion. For the latter, a smooth initial model is often preferred over a rough one. We test the inversion approach on synthetic elastic data computed for a single-layer P-wave model and on field data, both with a small vs/vp ratio. We find that a single-layer model can recover either the shallow or deeper part of the profile but not both, when compared with the result of a multi-layer inversion that we use as a reference. An extension of our analytic model to two layers above a homogeneous half-space, each with a constant vertical gradient of the squared P-wave slowness and connected in a continuous manner, improves the fit of the picked dispersion curves. The resulting profile resembles a smooth approximation of the multi-layered one but contains, of course, less detail. As it turns out, our method does not degrade as gracefully as, for instance, diving-wave tomography, and we can only hope to fit a subset of the dispersion curves. Therefore, the applicability of the method is limited to cases where the vs/vp ratio is small and the profile is sufficiently simple. A further extension of the two-layer model to more layers, each with a constant depth gradient of the squared slowness, might improve the fit of the modal structure but at an increased cost.","P-wave velocity profile; Squared-slowness gradient; Surface-wave inversion","en","journal article","","","","","","","","2018-07-31","","","Applied Geophysics and Petrophysics","","",""
"uuid:57e7bbeb-a3ad-4879-95c1-f5b99958e7be","http://resolver.tudelft.nl/uuid:57e7bbeb-a3ad-4879-95c1-f5b99958e7be","High-Performance and Low-Cost Sodium-Ion Anode Based on a Facile Black Phosphorus-Carbon Nanocomposite","Peng, B. (TU Delft ChemE/Materials for Energy Conversion and Storage; Renmin University of China); Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Liu, Kai (Renmin University of China); Wang, Xiaoqun (Renmin University of China; Shanghai Jiao Tong University); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2017","Black phosphorus (BP) has received increasing research attention as an anode material in sodium-ion batteries (SIBs), owing to its high capacity, electronic conductivity, and chemical stability. However, it is still challenging for BP-based SIB anodes to achieve a high electrochemical performance utilizing cost-effective materials and synthetic methods. This work presents a sodium-ion anode based on a BP-carbon nanocomposite synthesized from commercial red phosphorus and low-cost super P carbon black. Intimate interactions between BP and carbon are present, which helps to maintain the electrical conduction during cycling and, therefore, a high cycling stability is achieved. It exhibits a high capacity retention of 1381mAhg-1 for sodium-ion storage after 100 cycles, maintaining 90.5% of the initial reversible capacity. Such high performance/materials cost ratio may provide direction for future phosphorus-based anodes in high energy density SIBs.","Anode materials; Black phosphorus; Nanocomposites; Sodium-ion batteries","en","journal article","","","","","","","","2017-12-01","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:1656bbd3-d7d1-4942-919c-e8edc91fa1d5","http://resolver.tudelft.nl/uuid:1656bbd3-d7d1-4942-919c-e8edc91fa1d5","The electrochemical performance of super P carbon black in reversible Li/Na ion uptake","Peng, B. (TU Delft ChemE/Materials for Energy Conversion and Storage; Renmin University of China); Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Wang, Xiaoqun (Renmin University of China; Shanghai Jiao Tong University); Shi, Xinghua (National Center for Nanoscience and Technology (NCNST)); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2017","Super P carbon black (SPCB) has been widely used as a conducting additive in Li/Na ion batteries to improve the electronic conductivity. However, there has not yet been a comprehensive study on its structure and electrochemical properties for Li/Na ion uptake, though it is important to characterize its contribution in any study of active materials that uses this additive in non-negligible amounts. In this article the structure of SPCB has been characterized and a comprehensive study on the electrochemical Li/Na ion uptake capability and reaction mechanisms are reported. SPCB exhibits a considerable lithiation capacity (up to 310 mAh g–1) from the Li ion intercalation in the graphite structure. Sodiation in SPCB undergoes two stages: Na ion intercalation into the layers between the graphene sheets and the Na plating in the pores between the nano-graphitic domains, and a sodiation capacity up to 145 mAh g–1 has been achieved. Moreover, the influence of the type and content of binders on the lithiation and sodiation properties has been investigated. The cycling stability is much enhanced with sodium carboxymethyl cellulose (NaCMC) binder in the electrode and fluoroethylene carbonate (FEC) in the electrolyte; and a higher content of binder improves the Coulombic efficiency during dis-/charge.","Li ion batteries; Na ion batteries; super P carbon black","en","journal article","","","","","","","","2018-04-14","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:a81c52b0-3b76-43f0-a667-ff19eba7f5d1","http://resolver.tudelft.nl/uuid:a81c52b0-3b76-43f0-a667-ff19eba7f5d1","A simple finite-difference scheme for handling topography with the second-order wave equation","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2017","The presence of topography poses a challenge for seismic modeling with finite-difference codes. The representation of topography by means of an air layer or vacuum often leads to a substantial loss of numerical accuracy. A suitable modification of the finite-difference weights near the free surface can decrease that error. An existing approach requires extrapolation of interior solution values to the exterior while using the boundary condition at the free surface. However, schemes of this type occasionally become unstable and may be impossible to implement with highly irregular topography. One-dimensional extrapolation along coordinate lines results in a simple and efficient scheme. The stability of the 1D scheme is improved by ignoring the interior point nearest to the boundary during extrapolation in case its distance to the boundary is less than half a grid spacing. The generalization of the 1D scheme to more than one dimension requires a modification if the boundary intersects the finite-difference stencil on both sides of the central evaluation point and if there are not enough interior points to build the finite-difference stencil. Examples for the 2D constant-density acoustic case with a fourth-order finite-difference scheme demonstrate the method's capability. Because the 1D assumption is not valid in two dimensions if the boundary does not follow grid lines, the formal numerical accuracy is not always obtained, but the method can handle highly irregular topography.","","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:d72daf4c-d030-4d7d-97ee-42d9f8a2c2cc","http://resolver.tudelft.nl/uuid:d72daf4c-d030-4d7d-97ee-42d9f8a2c2cc","Efficient electricity storage with a battolyser, an integrated Ni-Fe battery and electrolyser","Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Weninger, B. (TU Delft ChemE/Materials for Energy Conversion and Storage); Middelkoop, J. (TU Delft ChemE/Chemical Engineering); Ooms, F.G.B. (TU Delft RST/Bedrijfsondersteuning); Schreuders, H. (TU Delft ChemE/Chemical Engineering)","","2017","Grid scale electricity storage on daily and seasonal time scales is required to accommodate increasing amounts of renewable electricity from wind and solar power. We have developed for the first time an integrated battery-electrolyser ('battolyser') that efficiently stores electricity as a nickel-iron battery and can split water into hydrogen and oxygen as an alkaline electrolyser. During charge insertion the Ni(OH)2 and Fe(OH)2 electrodes form nanostructured NiOOH and reduced Fe, which act as efficient oxygen and hydrogen evolution catalysts respectively. The charged electrodes use all excess electricity for efficient electrolysis, while they can be discharged at any time to provide electricity when needed. Our results demonstrate a remarkable constant and a high overall energy efficiency (80-90%), enhanced electrode storage density, fast current switching capabilities, and a general stable performance. The battolyser may enable efficient and robust short-term electricity storage and long-term electricity storage through production of hydrogen as a fuel and feedstock within a single, scalable, abundant element based device.","","en","journal article","","","","","","","","2017-12-14","","ChemE/Chemical Engineering","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:df7753b3-4137-4275-9442-e33f04bc18ed","http://resolver.tudelft.nl/uuid:df7753b3-4137-4275-9442-e33f04bc18ed","Towards assimilation of InSAR data in operational weather models","Mulder, G. (TU Delft Mathematical Geodesy and Positioning); van Leijen, F.J. (TU Delft Mathematical Geodesy and Positioning); Barkmeijer, Jan (Royal Netherlands Meteorological Institute (KNMI)); de Haan, Siebren (Royal Netherlands Meteorological Institute (KNMI)); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning)","","2017","InSAR signal delays due to the varying atmospheric refractivity are a potential data source to improve weathermodels [1]. Especially with the launch of the new Sentinel-1 satellites, which increases data coverage, latency andaccessibility, it may become possible to operationalize the assimilation of differential integrated refractivity (DIR)values in numerical weather models. Although studies exist on comparison between InSAR data and weathermodels [2], the impact of assimilation of DIR values in an operational weather model has never been assessed. Inthis study we present different ways to assimilate DIR values in an operational weather model and show the firstforecast results.","","en","abstract","","","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:2841cc0d-97f1-491a-a54a-48a38aed67f2","http://resolver.tudelft.nl/uuid:2841cc0d-97f1-491a-a54a-48a38aed67f2","Assimilation of InSAR-derived Atmospheric Data in Operational Weather Models","Mulder, G. (TU Delft Mathematical Geodesy and Positioning); van Leijen, F.J. (TU Delft Mathematical Geodesy and Positioning); Barkmeijer, Jan (Royal Netherlands Meteorological Institute (KNMI)); de Haan, Siebren (Royal Netherlands Meteorological Institute (KNMI)); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning)","","2017","The influence of signal delay due to the varying atmospheric refractivity can be significant in individual interferograms. This signal is generally considered to be noise in deformation studies, but it can also potentially be used to improve weather models [1]. This application has an enormous potential, because, contrary to deformation studies, every acquired SAR image contains valuable information on the state of the atmosphere.","","en","abstract","","","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:f5269cac-53f3-47b8-a707-7fa4714d7ffc","http://resolver.tudelft.nl/uuid:f5269cac-53f3-47b8-a707-7fa4714d7ffc","Doris 5 and Event-Triggered InSAR Processing","Levelt, D.F. (TU Delft Mathematical Geodesy and Positioning); Mulder, G. (TU Delft Mathematical Geodesy and Positioning); van Leijen, F.J. (TU Delft Mathematical Geodesy and Positioning); Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning)","","2017","","","en","abstract","","","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:37b89d9a-a33c-4fbb-a524-2fa92873733a","http://resolver.tudelft.nl/uuid:37b89d9a-a33c-4fbb-a524-2fa92873733a","Urban Symbiosis as a strategy for sustainabilising cities: An overview of options and their potential, pitfalls and solutions","Mulder, K.F. (TU Delft Organisation & Governance)","","2017","","","en","journal article","","","","","","","","","","","Organisation & Governance","","",""
"uuid:15031ca6-ae82-4d7f-92b4-e645a5ddf41c","http://resolver.tudelft.nl/uuid:15031ca6-ae82-4d7f-92b4-e645a5ddf41c","Admittance-adaptive model-based approach to mitigate biodynamic feedthrough","Venrooij, J. (Max Planck Institute for Biological Cybernetics); Mulder, Max (TU Delft Control & Operations); Mulder, M. (TU Delft Human-Robot Interaction; TU Delft Biomechatronics & Human-Machine Control); Abbink, D.A. (TU Delft Human-Robot Interaction; TU Delft Biomechatronics & Human-Machine Control); van Paassen, M.M. (TU Delft Control & Simulation); van der Helm, F.C.T. (TU Delft Biomechatronics & Human-Machine Control); Bulthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics)","","2017","Biodynamic feedthrough (BDFT) refers to the feedthrough of vehicle accelerations through the human body, leading to involuntary control device inputs. BDFT impairs control performance in a large range of vehicles under various circumstances. Research shows that BDFT strongly depends on adaptations in the neuromuscular admittance dynamics of the human body. This paper proposes a model-based approach of BDFT mitigation that accounts for these neuromuscular adaptations. The method was tested, as proof-of-concept, in an experiment where participants inside a motion simulator controlled a simulated vehicle through a virtual tunnel. Through evaluating tracking performance and control effort with and without motion disturbance active and with and without cancellation active, the effectiveness of the cancellation was evaluated. Results show that the cancellation approach is successful: the detrimental effects of BDFT were largely removed.","Biodynamic feedthrough (BDFT); mitigation; neuromuscular admittance; neuromuscular adaptation","en","journal article","","","","","","","","","","Control & Operations","Human-Robot Interaction","","",""
"uuid:50581890-e0ed-43b9-870e-d81806ad8209","http://resolver.tudelft.nl/uuid:50581890-e0ed-43b9-870e-d81806ad8209","The Influence of Discrimination Strategy on the JND in Human Haptic Perception of Manipulator","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2017","","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","2018-06-01","","Control & Operations","Control & Simulation","","",""
"uuid:6795ac4a-20b0-42da-86c3-3d5f7101d8eb","http://resolver.tudelft.nl/uuid:6795ac4a-20b0-42da-86c3-3d5f7101d8eb","A shear-wave seismic system using full waveform inversion to look ahead of a tunnel-boring machine","Bharadwaj, Pawan (TU Delft Applied Geophysics and Petrophysics); Drijkoningen, G.G. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics); Thorbecke, J.W. (TU Delft Applied Geophysics and Petrophysics); Neducza, Boriszlav (Geology and Geophysics (Geo2X)); Jenneskens, R (Seismic Mechatronics BV)","","2017","In the near surface with unconsolidated soils, shear-wave properties can often be characterised better and with a higher resolution than compressional-wave properties. To enable imaging ahead of a tunnel-boring machine, we developed a seismic prediction system with a few shear-wave vibrators and horizontal receivers. The boring process is interrupted at regular intervals to carry out active surveys. The vibrators are then pushed against the rock or soil in front of the cutting wheel of the machine. The design of the vibrators is based on linear synchronous motor technology that can generate very low frequencies, starting at 5 Hz. These vibrators generate a force in a direction perpendicular to the tunnel axis. Horizontal receivers measure the particle velocity, mainly due to the horizontally polarised shear waves. Because imaging with conventional migration methods suffers from artefacts, caused by the incomplete aperture and inaccuracies in the assumed velocity model, we use two-dimensional horizontally polarised shear full-waveform inversion to resolve the subsurface shear properties. The classic cycle-skipping problem, which can make the application of fullwaveform inversion cumbersome, is avoided by the capacity of the vibrators to generate low frequencies. In this paper, we demonstrate the capabilities of the proposed seismic system through a number of synthetic and field experiments.","","en","journal article","","","","","","","","2018-06-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:cb9380ac-805e-4bf2-8642-16d1d92c648d","http://resolver.tudelft.nl/uuid:cb9380ac-805e-4bf2-8642-16d1d92c648d","Salt reconstruction in full waveform inversion with a parametric level-set method","Kadu, Ajinkya (Universiteit Utrecht); van Leeuwen, Tristan (Universiteit Utrecht); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics)","","2017","Seismic full-waveform inversion tries to estimate subsurface medium parameters from seismic data. Areas with subsurface salt bodies are of particular interest because they often have hydrocarbon reservoirs on their sides or underneath. Accurate reconstruction of their geometry is a challenge for current techniques. This paper presents a parametric level-set method for the reconstruction of salt-bodies in seismic full-waveform inversion. We split the subsurface model in two parts: a background velocity model and a salt body with known velocity but undetermined shape. The salt geometry is represented by a level-set function that evolves during the inversion. We choose radial basis functions to represent the level-set function, leading to an optimization problem with a modest number of parameters. A common problem with level-set methods is to fine-tune the width of the level-set boundary for optimal sensitivity. We propose a robust algorithm that dynamically adapts the width of the level-set boundary to ensure faster convergence. Tests on a suite of idealized salt geometries show that the proposed method is stable against a modest amount of noise. We also extend the method to joint inversion of both the background velocity model and the salt geometry.","","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:351f0159-f7d1-41a1-8937-445af0d67feb","http://resolver.tudelft.nl/uuid:351f0159-f7d1-41a1-8937-445af0d67feb","An improved source term for finite-element modelling with the stress-velocity formulation of the wave equation","Shamasundar, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2017","For seismic modelling, imaging and inversion, finite-difference methods are still the workhorse of the industry despite their inability to meet the increasing demand for improved accuracy in subsurface imaging. Finiteelement methods offer better accuracy but at a higher computational cost. A stress-velocity formulation with linear elements and an iterative method, defect correction, for inverting the mass matrix offers fourth-order super-convergence but is susceptible to numerical noise if waves in the wrong part of the dispersion curve are excited. We propose an improved source term that reduces that noise and investigate the accuracy of the method on structured triangular meshes as well as on unstructured rotated meshes. With an optimised source function, it is seen that the dispersive wavelengths can be avoided, giving the defect-correction approach a better performance than the mass-lumped formulation with only a marginal increase in compute effort.","","en","conference paper","EAGE","","","","","","","2018-06-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:90f78d68-595d-4534-96b1-6e300470c610","http://resolver.tudelft.nl/uuid:90f78d68-595d-4534-96b1-6e300470c610","Higher-order source-wavefield reconstruction for reverse-time migration from stored values in a boundary strip just one point wide","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2017","Storage of the source wavefield during reverse-time migration and full-waveform inversion can be avoided by reconstructing that wavefield during reverse-time stepping along with the receiver wavefield. With absorbing boundary conditions, this requires the final states of the source wavefield and a strip of boundary values at all times. The width of the stored boundary strip, positioned in between the interior domain and the absorbing boundary region, usually equals about half that of the finite-difference stencil. The required storage in 3D with high frequencies can still adversely affect computational efficiency, despite the huge reduction in data volume compared to storing the source wavefields at all or appropriately subsampled time steps. A method is proposed that requires a boundary strip with a width of just one point. Stored boundary values over time enable the computation of the second and higher even derivatives normal to the boundary, which together with extrapolation from the interior provides stability and accuracy. Numerical tests show that the use of only the boundary values provides at most fourth-order accuracy for the reconstruction error in the source wavefield. With the higher even normal derivatives, higher orders can be reached as is demonstrated by examples up to order 26.","","en","conference paper","EAGE","","","","","","","2018-06-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:f80d9779-4905-4230-89b1-73439b9088e2","http://resolver.tudelft.nl/uuid:f80d9779-4905-4230-89b1-73439b9088e2","Acoustic VTI Full-waveform Inversion with 3-D Free-surface Topography","Huiskes, M.J. (Shell Global Solutions International B.V.); Plessix, RE (Shell Global Solutions International B.V.); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2017","In land applications, topography variation may impact the imaging if not taken into account. With low-frequency and wide-aperture data, the long-to-intermediate wavelength components of the velocity model can be recovered by full-waveform inversion. Standard static corrections to handle the topography do not work satisfactorily on long-offset data. We present a method to handle 3-D free-surface topography for acoustic FWI by directly modelling the effect of the topography with a finite-difference scheme for the first-order wave equation introduced earlier (Huiskes et al., 2016; Mulder and Huiskes, 2017). The method is based on an immersed interface approach (Lombard et al., 2008) in which the free surface does not have to coincide with the discretization grid, avoiding a staircase-like representation of the topography (Bohlen and Saenger, 2006). We refer to Huiskes et al. (2016) for a more detailed overview of methods for simulating seismic waves interacting with free-surface topography. First, we review the main elements of the numerical scheme that is designed specifically for discretization on standard staggered grids (SSG) using high-order derivative operators, which are modified based on their relative position to the free surface. Next, we extend the approach to vertical transverse isotropic (VTI) media to be able to model velocity anisotropy required in long-offset inversions. In relatively simple synthetic experiments, we then reproduce topography artefacts we have seen on real land fullwaveform inversions, allowing us to quantify the effect of elevation variation on the inversion accuracy.","","en","conference paper","EAGE","","","","","","","2018-06-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:e3e18073-acdc-4389-b6b4-9a16c41eb5e3","http://resolver.tudelft.nl/uuid:e3e18073-acdc-4389-b6b4-9a16c41eb5e3","Flight Testing and Preliminary Analysis for Global System Identification of Ornithopter Dynamics Using On-board and Off-board Data","Armanini, S.F. (TU Delft Control & Simulation); Karasek, M. (TU Delft Control & Simulation); de Visser, C.C. (TU Delft Control & Simulation); de Croon, G.C.H.E. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2017","br","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","2018-06-09","","Control & Operations","Control & Simulation","","",""
"uuid:501c4689-d381-4e0f-9357-000e0795eed9","http://resolver.tudelft.nl/uuid:501c4689-d381-4e0f-9357-000e0795eed9","Objective Inceptor Cueing Test for Control Loading Systems: Principle and Initial Design","Fu, W. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2017","","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","2018-07-01","","Control & Operations","Control & Simulation","","",""
"uuid:f6eecfeb-0059-4a5b-8563-f7c610f65947","http://resolver.tudelft.nl/uuid:f6eecfeb-0059-4a5b-8563-f7c610f65947","A simple finite-difference scheme for handling topography with the first-order wave equation","Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.); Huiskes, M.J. (Shell Global Solutions International B.V.)","","2017","One approach to incorporate topography in seismic finite-difference codes is a local modification of the difference operators near the free surface. An earlier paper described an approach for modelling irregular boundaries in a constant-density acoustic finite-difference code, based on the second-order formulation of the wave equation that only involves the pressure. Here, a similar method is considered for the first-order formulation in terms of pressure and particle velocity, using a staggered finite-difference discretization both in space and in time. In one space dimension, the boundary conditions consist in imposing antisymmetry for the pressure and symmetry for particle velocity components. For the pressure, this means that the solution values as well as all even derivatives up to a certain order are zero on the boundary. For the particle velocity, all odd derivatives are zero. In 2D, the 1-D assumption is used along each coordinate direction, with antisymmetry for the pressure along the coordinate and symmetry for the particle velocity component parallel to that coordinate direction. Since the symmetry or antisymmetry should hold along the direction normal to the boundary rather than along the coordinate directions, this generates an additional numerical error on top of the time stepping errors and the errors due to the interior spatial discretization. Numerical experiments in 2D and 3D nevertheless produce acceptable results","","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:909d636f-5381-49f4-8c11-a404d3d58163","http://resolver.tudelft.nl/uuid:909d636f-5381-49f4-8c11-a404d3d58163","Time and Energy Management During Approach: A Human-in-the-Loop Study","de Jong, P.M.A. (TU Delft Control & Simulation); Bussink, F. J L (Royal Netherlands Aerospace Centre NLR); Verhoeven, RPM (Royal Netherlands Aerospace Centre NLR); de Gelder, N (Royal Netherlands Aerospace Centre NLR); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2017","","","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:3611d4a9-0588-409b-b01d-62c6ae12baf0","http://resolver.tudelft.nl/uuid:3611d4a9-0588-409b-b01d-62c6ae12baf0","Strategic innovation tools enabling nautical stakeholders to shape a next level port","Nieuwsma, Garmt (Havenlab); Mulder, I. (TU Delft Design Conceptualization and Communication)","","2017","The current study explores how strategic design can foster innovation within the nautical process. With a focus on creating and learning by doing, strategic design can generate value among the nautical stakeholders. The nautical (operational) process has been explored in detail and translated into boundary objects to facilitate and foster strategic innovation in the nautical innovation process. It can be concluded that these objects have unlocked different perspectives, and enabled the nautical stakeholders to make their implicit knowledge explicit, and to co-construct the nautical process together. The objects remove boundaries in transferring knowledge while recognising people’s values, demands, and communication skills. Next to that, varying the use of the boundary objects in creating innovation in the nautical process seems to be valuable in structuring and collaboratively innovating. Besides, the application of the boundary objects into practice established an increasing level of attachment to both process and results.","Co-Creation; Innovation; Port Industry; Research through Design; Strategic Design","en","journal article","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:a1aca01f-3401-493d-a842-3da369e9a615","http://resolver.tudelft.nl/uuid:a1aca01f-3401-493d-a842-3da369e9a615","Improving the performance of si-based li-ion battery anodes by utilizing phosphorene encapsulation","Peng, B. (TU Delft ChemE/Materials for Energy Conversion and Storage; Renmin University of China); Xu, Y. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2017","Si-based anode materials in Li-ion batteries (LIBs) suffer from severe volume expansion/contraction during repetitive discharge/charge, which results in the pulverization of active materials, continuous growth of solid electrolyte interface (SE!) layers, loss of electrical conduction, and, eventually, battery failure. Herein, we present unprecedented low-content phosphorene (single-layer black phosphorus) encapsulation of silicon particles as an effective method for improving the electrochemical performance of Si-based LIB anodes. The incorporation of low phosphorene amounts (1%, mass fraction) into Si anodes effectively suppresses the detrimental effects of volume expansion and SE! growth, preserving the structural integrity of the electrode during cycling and achieving enhanced Coulombic efficiency, capacity retention, and cycling stability for Li-ion storage. Thus, the developed method can also be applied to other battery materials with high energy density exhibiting substantial volume changes.","Anode materials; Li ion battery; Phosphorene; Silicon","en","journal article","","","","","","","","2018-05-24","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:6de81686-a2b3-4edc-8215-e83db39750da","http://resolver.tudelft.nl/uuid:6de81686-a2b3-4edc-8215-e83db39750da","Ten types of emerging city makers","de Koning, J.I.J.C. (TU Delft Design Conceptualization and Communication; DRIFT: Dutch Research Institute for Transitions); Puerari, E. (TU Delft Design Conceptualization and Communication; DRIFT: Dutch Research Institute for Transitions); Mulder, I. (TU Delft Design Conceptualization and Communication); Loorbach, Derk (DRIFT: Dutch Research Institute for Transitions)","Sevaldson, B. (editor)","2017","","Urban Planning; Participatory Design; Sustainability Transitions; Rotterdam","en","conference paper","","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:fcdaf945-8a00-43f4-a375-614839cba37b","http://resolver.tudelft.nl/uuid:fcdaf945-8a00-43f4-a375-614839cba37b","Time-varying perceived motion mismatch due to motion scaling in curve driving simulation","van Leeuwen, T.D.; Cleij, D. (TU Delft Control & Simulation; Max Planck Institute); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); Bülthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics)","","2017","","","en","abstract","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:719701f9-a4dc-4f04-a577-a049abfcbef8","http://resolver.tudelft.nl/uuid:719701f9-a4dc-4f04-a577-a049abfcbef8","Measuring and Modeling Driver Steering Behavior: From Compensatory Tracking to Curve Driving","van der El, Kasper (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2017","","","en","abstract","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:537bdc24-9b7c-49f8-996a-2616d79d1340","http://resolver.tudelft.nl/uuid:537bdc24-9b7c-49f8-996a-2616d79d1340","Manual control cybernetics: State-of-the-art and current trends","Mulder, Max (TU Delft Control & Operations); Pool, D.M. (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Human-Robot Interaction); Boer, E.R. (TU Delft Human-Robot Interaction); Zaal, P.M.T. (TU Delft Control & Simulation; San José State University); Drop, F.M. (TU Delft Control & Simulation); van der El, Kasper (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2017","Manual control cybernetics aims to understand and describe how humans control vehicles and devices using mathematical models of human control dynamics. This “cybernetic approach” enables objective and quantitative comparisons of human behavior, and allows a systematic optimization of human control interfaces and training associated with manual control. Current cybernetics theory is primarily based on technology and analysis methods formalized in the 1960s and has shown to be limited in its capability to capture the full breadth of human cognition and control. This paper reviews the current state-of-the-art in our knowledge of human manual control, points out the main fundamental limitations in cybernetics, and proposes a possible roadmap to advance the theory and its applications. Central in this roadmap will be a shift from the current linear time-invariant modeling approach that is only truly valid for human behavior under tightly controlled and stationary conditions, to methods that facilitate the analysis of adaptive, and possibly time-varying, human behavior in realistic control tasks. Examples of key current developments in the field of cybernetics—human use of preview, predictable discrete maneuvering, skill acquisition and training, time-varying human modeling, and neuromuscular system modeling—that contribute to this shift are presented in this paper. The new foundations for cybernetics that will emerge from these efforts will impact all domains that involve humans in manual and semiautomatic control.","Adaptation models; Control systems; Cybernetics; dynamic behavior; Human factors; man–machine systems; manual control; modeling; Organizations; Visual perception","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:4d71dc49-3a81-4b87-a144-2237671f6793","http://resolver.tudelft.nl/uuid:4d71dc49-3a81-4b87-a144-2237671f6793","Strategies for food longevity","van Genuchten, E.J.S. (TU Delft Education and Student Affairs); Mulder, I. (TU Delft Design Conceptualization and Communication); Schaaf, N. (ConComCow)","Bakker, C. (editor); Mugge, R. (editor)","2017","Although food has been circular by nature, the current food supply chain has turned into an unfortunate linear system. The challenges of transitioning towards a sustainable food eco-system requires radical changes and new perspectives, where things are done differently. Starting with related work in the field of design for product longevity, the current work explores the role of design in developing food systems on eco-systemic level that work as efficient as possible, and create a world without waste. Eight local initiatives in Rotterdam have been studied. From the lessons learned, nine strategies were formulated. Although these strategies seem to work well and are promising starting points for innovation, it remains difficult to build sustainable business models around these strategies that can be scaled and sustained. Initiatives oftentimes keep struggling with the current system and finding the proper scale for their business. It can be
concluded that design promises to play an important role in accelerating this transition towards a circular and future-proof food system.","Design for sustainability; Emerging initiatives; Food; Product longevity; TransitionS","en","conference paper","IOS Press","","","","","","","","","","Education and Student Affairs","","",""
"uuid:b0c0e88a-6da0-45ca-bea9-ebd501c49a90","http://resolver.tudelft.nl/uuid:b0c0e88a-6da0-45ca-bea9-ebd501c49a90","MRI Mouse Brain Data of Ischemic Lesion after Transient Middle Cerebral Artery Occlusion","Mulder, Inge A. (Leiden University Medical Center); Khmelinskii, Artem (Leiden University Medical Center; University of Twente; Netherlands Cancer Institute); Dzyubachyk, Oleh (Leiden University Medical Center); De Jong, Sebastiaan (Max Planck Institute for Metabolism Research); Wermer, Marieke J.H. (Leiden University Medical Center); Hoehn, Mathias (Leiden University Medical Center; University of Twente; Max Planck Institute for Metabolism Research); Lelieveldt, B.P.F. (TU Delft Pattern Recognition and Bioinformatics; Leiden University Medical Center); van den Maagdenberg, Arn M.J.M. (Leiden University Medical Center)","","2017","In this data report we make available to the community a highly variable longitudinal MRI mouse brain data set of ischemic lesion after transient middle cerebral artery occlusion (tMCAo). Together with the provided semi-automated and automated segmentations, these data can be used to further improve the method proposed by Mulder et al. (2017) and also to serve as a benchmark for comparison between different approaches to segment ischemic lesions in MRI mouse brain data. It can also be used to develop and validate algorithms that further classify the stroke area into core and penumbra.
• The data were collected from mice: (i) of different ages, (ii) of two different strains, (iii) at different time points after the ischemic infarct induction, (iv) from two laboratories, (v) using two different MRI systems, and (vi) using three different sets of acquisition parameters.
• Segmentations of the ischemic lesions are provided as well. These were obtained by: (i) two observers using a semi-automated method and (ii) using the novel automated segmentation approach described by Mulder et al. (2017).
• Type/format of data: raw files, MetaImage files, text/Excel files, analyzed data.
• The following set of images associated with each of the 121 scans is included: raw Bruker MRI data (reference scan, T2 scan with all echoes, calculated T2-weighted map), automated segmentations of the ischemic lesions and semi-automated segmentations by two observers.
• For 99 of these scans, an accompanying set of Bruker MR diffusion maps, containing the Diffusion-Weighted Image (DWI) and calculated Apparent Diffusion Coefficient (ADC) maps, is included.
• Acquisition hardware: small-animal Bruker MRI systems (7 T and 11.7 T).
• Experimental set-up: infarct was induced in male mice of different age and background, using the tMCAo model. After that, MRI scans at different time points after infarct induction were acquired.
• Data sources: Leiden, Netherlands; Cologne, Germany.
• Data accessibility: all related data sets (121 T2 scans + template + 99 diffusion scans) were deposited in the public Dryad Digital Repository (https://doi.org/10.5061/dryad.1m528).","Brain; Data collection; Ischemic stroke; Mouse; MRI","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:dec47ad2-dfa7-4969-a208-512f437b1d6d","http://resolver.tudelft.nl/uuid:dec47ad2-dfa7-4969-a208-512f437b1d6d","Designing for Situation Awareness: the World behind the Glass","Mulder, Max (TU Delft Control & Operations); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation)","","2017","In the design of human-machine interfaces and automation, an important question is how to obtain and validate a design that is capable of supporting the operator’s understanding and situation awareness of the process under control. Whereas many research efforts address the question of ‘what is the operator aware of?’ – the awareness – only a few investigations focus on studying what the operator should be aware of in the first place, i.e., ‘what is the situation?’ In this paper we briefly discuss some of our research activities which aim at answering this second question, following an ‘ecological approach’ to interface design. The clever use of automation tools and novel visualizations will be presented that allows human operators working in aviation (pilots, air traffic controllers) in dealing with complex tasks. The airborne self-separation task will be discussed, as an example of showing how ecological interfaces can support pilots in their decision making","Human-machine Systems; Automation; Cockpits; Aerospace","en","conference paper","SciTePress","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:67f92410-9e5a-452f-8fba-713f8d084cd2","http://resolver.tudelft.nl/uuid:67f92410-9e5a-452f-8fba-713f8d084cd2","Toward Functional Augmented Reality in Marine Navigation: A Cognitive Work Analysis","Procee, S. (Maritiem Instituut Willem Barentsz); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Bertram, V. (editor)","2017","Augmented Reality, (AR) also known as vision-overlay, can help the navigator to visually detect a dangerous target by the overlay of a synthetic image, thus providing a visual cue over the real world. This is the first paper of a series about the practicalities and consequences of implementing AR in marine navigation. A Cognitive Work Analysis is carried out to derive a scientific base for a functional
interface that best supports navigators in their work.","","en","conference paper","Technische Universität Hamburg-Harburg","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:71b81644-e487-4fc1-aa6b-b691e2d90de2","http://resolver.tudelft.nl/uuid:71b81644-e487-4fc1-aa6b-b691e2d90de2","Automated Ischemic Lesion Segmentation in MRI Mouse Brain Data after Transient Middle Cerebral Artery Occlusion","Mulder, Inge A. (Leiden University Medical Center); Khmelinskii, Artem (Leiden University Medical Center; Percuros B.V); Dzyubachyk, Oleh (Leiden University Medical Center); de Jong, Sebastiaan (Leiden University Medical Center); Rieff, Nathalie (Leiden University Medical Center); Wermer, Marieke J.H. (Leiden University Medical Center); Hoehn, Mathias (Leiden University Medical Center; Percuros B.V; Max Planck Institute for Metabolism Research); Lelieveldt, B.P.F. (TU Delft Pattern Recognition and Bioinformatics; Leiden University Medical Center); van den Maagdenberg, Arn M.J.M. (Leiden University Medical Center)","","2017","Magnetic resonance imaging (MRI) has become increasingly important in ischemic stroke experiments in mice, especially because it enables longitudinal studies. Still, quantitative analysis of MRI data remains challenging mainly because segmentation of mouse brain lesions in MRI data heavily relies on time-consuming manual tracing and thresholding techniques. Therefore, in the present study, a fully automated approach was developed to analyze longitudinal MRI data for quantification of ischemic lesion volume progression in the mouse brain. We present a level-set-based lesion segmentation algorithm that is built using a minimal set of assumptions and requires only one MRI sequence (T2) as input. To validate our algorithm we used a heterogeneous data set consisting of 121 mouse brain scans of various age groups and time points after infarct induction and obtained using different MRI hardware and acquisition parameters. We evaluated the volumetric accuracy and regional overlap of ischemic lesions segmented by our automated method against the ground truth obtained in a semi-automated fashion that includes a highly time-consuming manual correction step. Our method shows good agreement with human observations and is accurate on heterogeneous data, whilst requiring much shorter average execution time. The algorithm developed here was compiled into a toolbox and made publically available, as well as all the data sets.","Automated segmentation; Ischemic stroke; Lesion; Mouse; MRI; Quantification; Volume","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:cf37b851-f37e-44cc-aaf7-bcde6996b94c","http://resolver.tudelft.nl/uuid:cf37b851-f37e-44cc-aaf7-bcde6996b94c","Ecological interface design: supporting fault diagnosis of automated advice in a supervisory air traffic control task","Borst, C. (TU Delft Control & Simulation); Bijsterbosch, V.A. (TU Delft Education AE); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2017","Future air traffic control will have to rely on more advanced automation to support human controllers in their job of safely handling increased traffic volumes. A prerequisite for the success of such automation is that the data driving it are reliable. Current technology, however, still warrants human supervision in coping with (data) uncertainties and consequently in judging the quality and validity of machine decisions. In this study, ecological interface design was used to assist controllers in fault diagnosis of automated advice, using a prototype ecological interface (called the solution space diagram) for tactical conflict detection and resolution in the horizontal plane. Results from a human-in-the-loop simulation, in which sixteen participants were tasked with monitoring automation and intervening whenever required or desired, revealed a significant improvement in fault detection and diagnosis in a complex traffic scenario. Additionally, the experiment also exposed interesting interaction patterns between the participants and the advisory system, which seemed unrelated to the fault diagnosis task. Here, the explicit means-ends links appeared to have affected participants’ control strategy, which was geared toward taking over control from automation, regardless of the fault condition. This result suggests that in realizing effective human-automation teamwork, finding the right balance between offering more insight (e.g., through ecological interfaces) and striving for compliance with single (machine) advice is an avenue worth exploring further.","Air traffic control; Automation; Decision making; Ecological interface design; Sensor failure; Supervisory control","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:29925ebb-d83e-40f5-ac22-23a115a76d6c","http://resolver.tudelft.nl/uuid:29925ebb-d83e-40f5-ac22-23a115a76d6c","Shaping Spaces of Interaction for Sustainable Transitions","Puerari, E. (TU Delft Design Conceptualization and Communication; DRIFT: Dutch Research Institute for Transitions); de Koning, J.I.J.C. (TU Delft Design Conceptualization and Communication; DRIFT: Dutch Research Institute for Transitions); Mulder, I. (TU Delft Design Conceptualization and Communication); Loorbach, Derk (DRIFT: Dutch Research Institute for Transitions)","Ferreira, J.A. (editor); Simões, J.M. (editor); Morgado, S. (editor)","2017","","","en","conference paper","Universidade de Lisboa","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:847bece5-2796-489b-9f04-470f59411d6c","http://resolver.tudelft.nl/uuid:847bece5-2796-489b-9f04-470f59411d6c","Parametric level-set full-waveform inversion in the presence of salt bodies","Kadu, Ajinkya (Universiteit Utrecht); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics); van Leeuwen, Tristan (Universiteit Utrecht)","Mihai Popovici, A. (editor); Fomel, S. (editor)","2017","Full-waveform inversion attempts to estimate a high-resolution model of the Earth by inverting all the seismic data. This procedure fails if the Earth model contains high-contrast bodies such as salt and if su ciently low frequencies are absent from the data. Salt bodies are important for hydrocarbon exploration because oil or gas reservoirs are often located on their sides or underneath. We represent the shape of the salt body with a level set, constructed from radial basis functions to keep its dimensionality low. We have shown earlier that the salt body can be completely recovered if the sediment structure is already known. In this paper, we propose a strategy to simultaneously reconstruct the sediment and the salt. The sediment is implicitly represented by a bilinear interpolation kernel with a small number of variables. An alternating minimization technique solves the resulting optimization problem. The results on a synthetic model using Gauss-Newton approximation of the Hessian shows the feasibility of the approach","","en","conference paper","SEG","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:a640075b-30a7-45b0-bd16-3d5a4fb041e5","http://resolver.tudelft.nl/uuid:a640075b-30a7-45b0-bd16-3d5a4fb041e5","Increasing Acceptance of Haptic Feedback on UAV Teleoperations by Visualizing Force Fields","Ho, V. (Student TU Delft); Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Tsang, P.S. (editor); Vidulich, M.A. (editor)","2017","In tele-operating an UAV human operators fully rely on cameras to control the vehicle from a distance. To increase operator situation awareness and reduce workload, a haptic feedback on the control stick has been developed which acts as an automatic collision avoidance system. A virtual force field surrounding the moving vehicle interacts with obstacles surrounding it, yielding repulsive forces on the stick that lead the vehicle away from them. Albeit successful in significantly reducing the number of collisions, the haptic interface received low user acceptance ratings. Operators do not always fully understand the collision avoidance automation intentions, and they experience the haptic forces as intrusive. This paper discusses the development and testing of several visualizations of the underlying automation intentions, primarily the artificial force field. Results of a human-in-the-loop experiment show that these visualizations indeed led to higher user acceptance ratings, without affecting the operator’s safety, performance and workload.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:87b2e955-9afc-4771-a429-ca5f4f99213e","http://resolver.tudelft.nl/uuid:87b2e955-9afc-4771-a429-ca5f4f99213e","Does the Projected-Hand-Illusion Help in Teleoperation?","Wajon, Lloyd (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Human-Robot Interaction); Boer, E.R. (TU Delft Human-Robot Interaction); Mulder, Max (TU Delft Control & Operations)","Tsang, P.S. (editor); Vidulich, M.A. (editor)","2017","A body illusion, commonly known in the form of the “Rubber Hand Illusion”, is an illusion wherein visual inputs on an inanimate object and simultaneous tactile inputs on a part of the body lead to a situation where the inanimate object is identified as the body part. This study investigated the possibility of inducing a body illusion during a teleoperated reaching task, to see if this leads to increased telepresence and improved accuracy. Three conditions were presented in random order; the Direct Control (DC) condition, where the participant’s hand is shown on the screen, the Projected Hand Illusion (PHI) condition, showing the slave device consisting of a 3D-printed hand designed to induce a body illusion, and the no Projected Hand Illusion (nPHI) condition, showing the slave device consisting of a 3D-printed object of appropriate shape but designed to not induce a body illusion. Reaching performance was interpreted in terms of position error, for which a significant difference was found between conditions PHI and nPHI. In the nPHI condition, participants kept more distance to the obstacle than in the PHI condition. Potential causes for this difference are an increased perception of risk due to a difference in visual perception, or subtle visual differences in between the two conditions.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:89439c34-39f1-4a18-bc42-07ca1b63d99b","http://resolver.tudelft.nl/uuid:89439c34-39f1-4a18-bc42-07ca1b63d99b","Adaptive Automation Based on Air Traffic Controller Decision-Making","IJtsma, Martijn (Student TU Delft); Borst, C. (TU Delft Control & Simulation); Mercado Velasco, G.A. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); van Paassen, M.M. (TU Delft Control & Simulation)","Tsang, P.S. (editor); Vidulich, M.A. (editor)","2017","Through smart scheduling and triggering of automation support, adaptive automation has the potential to balance air traffic controller workload. The challenge in the design of adaptive automation systems is to decide how and when the automation should provide support. This paper describes the design of a novel mechanism for adaptively invoking automation support. Whereas most adaptive automation support systems are reactive in that they invoke automation support after controller workload has increased, the aim of the designed mechanism is to proactively trigger automation support prior to workload increases. To do this, the mechanism assesses the quality of air traffic controller's decisions. The designed adaptive automation system has been tested in a human-in-the-loop experiment. Results indicate that the adaptive support helps to increase efficiency and safety as compared to manual control. However, lower triggering thresholds (resulting in more frequent automation intervention) increased the frustration level of participants (as measured with NASA TLX) and decreased acceptance of the support.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:95a3248f-92ac-4aa2-b98e-48bccccbbd50","http://resolver.tudelft.nl/uuid:95a3248f-92ac-4aa2-b98e-48bccccbbd50","The effect of surprise on upset recovery performance","Landman, H.M. (TU Delft Control & Simulation; TNO); Groen, Eric L. (TNO); van Paassen, M.M. (TU Delft Control & Simulation); Bronkhorst, Adelbert W. (TNO); Mulder, Max (TU Delft Control & Operations)","Tsang, P.S. (editor); Vidulich, M.A. (editor)","2017","Introducing the element of surprise is one of the main challenges in simulator training of in-flight emergencies. In this simulator study, we investigated the differences in performance between predictable and surprising circumstances, in order to obtain insight into the transfer of training between predictable training settings and surprising circumstances in operational practice. This was done by testing twenty airline pilots who recovered from an aerodynamic stall in two conditions: one anticipation condition and one surprise condition. All pilots practiced beforehand using predictable, or nonsurprising scenarios. The results show that pilots had significantly more difficulties in adhering to components of the FAA-commissioned recovery template in the surprise condition compared to the anticipation condition. These results suggest that predictable training may not be enough to prevent serious performance decrements under surprise.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:d93906dd-7e61-44b2-ad55-bc39ac274ee5","http://resolver.tudelft.nl/uuid:d93906dd-7e61-44b2-ad55-bc39ac274ee5","Effects of an Ecological Interface on Flight Training Effectiveness","Deerenberg, Ronald (Student TU Delft); van Paassen, M.M. (TU Delft Control & Simulation); Borst, C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Tsang, P.S. (editor); Vidulich, M.A. (editor)","2017","For Ecological Interface Design (EID), the underlying constraints and properties of an operator’s work domain are analysed and used as a basis for the design of the information displays, so that these may reveal these underlying mechanisms. Most evaluations for EID have been performed with expert or trained participants. However, it can be hypothesised that the effects of EID will also change the way tasks are learned by novices; since the EID designs support direct manipulation, and at the same time show the constraints in the work domain, a novice would be able to perform the task as a skill, employing the direct manipulation features of the interface, while at the same time learning the underlying constraints from the work domain. Our interest is the effect of an EID display on skill acquisition in a flying task. To this end we evaluated the EID display by (Amelink, Mulder, van Paassen, & Flach, 2005) in a study with novice pilots, learning flight path and speed control of a simulated aircraft. It was found that initial performance by the EID group was better than by a control group, the EID group also showed more consistent and homogeneous behavior. The EID display did not lead to increased workload, as measured with the Rating Scale for Mental Effort. Asymptotic performance levels for both groups were not significantly different.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:e373d4cc-67ed-4532-aa8f-bfc70af7771c","http://resolver.tudelft.nl/uuid:e373d4cc-67ed-4532-aa8f-bfc70af7771c","Strategic competences for concrete action towards sustainability: An oxymoron? Engineering education for a sustainable future","Mulder, K.F. (TU Delft Environmental Technology and Design; The Hague University of Applied Sciences)","","2017","In the current discourses on sustainable development, one can discern two main intellectual cultures: an analytic one focusing on measuring problems and prioritizing measures, (Life Cycle Analysis (LCA), Mass Flow Analysis (MFA), etc.) and; a policy/management one, focusing on long term change, change incentives, and stakeholder management (Transitions/niches, Environmental economy, Cleaner production).These cultures do not often interact and interactions are often negative. However, both cultures are required to work towards sustainability solutions: problems should be thoroughly identified and quantified, options for large change should be guideposts for action, and incentives should be created, stakeholders should be enabled to participate and their values and interests should be included in the change process. The paper deals especially with engineering education. Successful technological change processes should be supported by engineers who have acquired strategic competences. An important barrier towards training academics with these competences is the strong disciplinarism of higher education. Raising engineering students in strong disciplinary paradigms is probably responsible for their diminishing public engagement over the course of their studies. Strategic competences are crucial to keep students engaged and train them to implement long term sustainable solutions.","Engineering culture; Engineering education; Interdisciplinarity; Paradigm; Strategic competences; Transitions","en","journal article","","","","","","","","","","","Environmental Technology and Design","","",""
"uuid:e71a62bd-22d0-4b16-bbfc-7fb00f85ffe7","http://resolver.tudelft.nl/uuid:e71a62bd-22d0-4b16-bbfc-7fb00f85ffe7","Objective Model Selection for Identifying the Human Feedforward Response in Manual Control","Drop, F.M. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); Bülthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics)","","2017","Realistic manual control tasks typically involve predictable target signals and random disturbances. The human controller (HC) is hypothesized to use a feedforward control strategy for target-following, in addition to feedback control for disturbance-rejection. Little is known about human feedforward control, partly because common system identification methods have difficulty in identifying whether, and (if so) how, the HC applies a feedforward strategy. In this paper, an identification procedure is presented that aims at an objective model selection for identifying the human feedforward response, using linear time-invariant autoregressive with exogenous input models. A new model selection criterion is proposed to decide on the model order (number of parameters) and the presence of feedforward in addition to feedback. For a range of typical control tasks, it is shown by means of Monte Carlo computer simulations that the classical Bayesian information criterion (BIC) leads to selecting models that contain a feedforward path from data generated by a pure feedback model: “false-positive” feedforward detection. To eliminate these false-positives, the modified BIC includes an additional penalty on model complexity. The appropriate weighting is found through computer simulations with a hypothesized HC model prior to performing a tracking experiment. Experimental human-in-the-loop data will be considered in future work. With appropriate weighting, the method correctly identifies the HC dynamics in a wide range of control tasks, without false-positive results.","Feedforward control; human control models; manual control; parameter estimation; system identification","en","journal article","","","","","","","","2018-01-01","","Control & Operations","Control & Simulation","","",""
"uuid:3597c39f-7179-4ebe-b65e-73402f064c63","http://resolver.tudelft.nl/uuid:3597c39f-7179-4ebe-b65e-73402f064c63","The use of pilot ratings in rotorcraft flight simulation fidelity assessment","Miletović, I. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Stroosma, O. (TU Delft Control & Simulation); Pavel, M.D. (TU Delft Control & Simulation); Wentink, M (Desdemona B.V.); Mulder, Max (TU Delft Control & Operations)","","2017","The fidelity of a rotorcraft flight simulator is influenced by many factors, such as the vehicle dynamic model and the motion cueing algorithm (MCA). To quantify the fidelity of a simulator objectively requires detailed knowledge of human pilot perception and control behaviour that is not yet available. As a consequence, subjective assessments made by qualified pilots remain the most important way to assess flight simulation fidelity. The use of standardized rating scales during such assessments can increase the level of objectivity above that provided by less structured evaluations. The current paper describes the result of an experiment performed on the Desdemona simulator to evaluate two rating scales, namely the Simulator Fidelity Rating (SFR) scale and the Motion Fidelity Rating (MFR) scale, as suitable indicators of flight simulation fidelity. In this experiment, two characteristics of the simulated environment were varied, namely rotorcraft dynamics and MCA configuration, and the type of rating scale used was treated as an additional independent variable. The primary results of the experiments suggest that pilots are able to recognize a strong decline in flight simulation fidelity when both rotorcraft dynamics and motion are degraded simultaneously. However, when either one of these characteristics are varied independently of the other, the results are inconclusive. The paper presents a more detailed review of the various results gathered during the experiment and formulates recommendations for future experiments in rotorcraft flight simulation fidelity assessment that involve the use of pilot ratings.","","en","conference paper","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:f8b6e015-0a0f-4feb-a313-ae680aac34ea","http://resolver.tudelft.nl/uuid:f8b6e015-0a0f-4feb-a313-ae680aac34ea","Estimating driver time-varying neuromuscular admittance through LPV model and grip force","Pronker, A.J.; Abbink, D.A. (TU Delft Human-Robot Interaction); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Dochain, D. (editor); Henrion, D. (editor); Peaucelle, D. (editor)","2017","Humans can rapidly change their low-frequency arm dynamics (i.e., stiffness) to resist forces or give way to them. Quantifying driver’s time-varying arm dynamics is important for the development of steer-by-wire systems and haptic driver support systems. Conventional LTI identification, and even time-varying techniques such as wavelets, fail to capture rapidly-varying low-frequency dynamics. In this study, we propose to estimate driver admittance in real-time, using grip force measurement of the hands on the steering wheel and linear parameter-varying (LPV) modeling techniques. We hypothesized that grip force is strongly correlated to neuromuscular admittance, and can serve as an appropriate scheduling variable for an LPV model. We performed an experiment in which 18 subjects performed a boundary tracking task, and applied torque perturbations to the steering wheel to perform a baseline LTI identification. Six different boundary widths were used to evoke changes in admittance, while their grip force was measured with pressure gloves. A global LPV model is identified by linear interpolation between the local LTI models identified for each boundary width. The estimated stiffness and damping parameters varied proportionally with the grip force. Although small between-subject variations in grip force levels are found, we conclude that grip force can indeed serve as an appropriate scheduling variable for a global LPV model, which is capable of tracking fast-changing admittance changes. Future work focuses on using the LPV model in realistic driving tasks, permitting admittance estimates to be obtained without the need to apply external disturbance torques on the steering wheel.","Human-machine systems; admittance; driver models; parameter identification","en","conference paper","Elsevier","","","","","","","","","Control & Operations","Human-Robot Interaction","","",""
"uuid:c66b2f6a-a77c-4a92-879b-33a8a5d5de0a","http://resolver.tudelft.nl/uuid:c66b2f6a-a77c-4a92-879b-33a8a5d5de0a","Experimental Scheduling Functions for Global LPV Human Controller Modeling","Duarte, R.F.M.; Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Dochain, D. (editor); Henrion, D. (editor); Peaucelle, D. (editor)","2017","In this paper, the Linear Parameter Varying (LPV) model identification framework is applied to estimating time-varying human controller (HC) dynamics in a single-loop tracking task. Given the inherently unknown time changes in HC behavior, a global LPV approach with experimentally determined Scheduling Functions (SFs) is needed for this application. In this paper, a methodology based on the Predictor-Based Subspace Identification (PBSID) algorithm is tested. Using Monte Carlo simulation data matching a recent experimental study, two experimental SFs derived from measured HC control inputs are tested for their LPV model identification performance. The results are compared with LPV models obtained using the true (analytical) SFs used for generating the simulation data. An experimental SF obtained from the double derivative of HCs’ control inputs using zero-phase low-pass filtering was found to yield time-varying HC model estimates of equivalent accuracy as obtained with the analytical SFs; a promising result for future application of this methodology to measured HC behavior.","Human-machine systems; Manual control; Time-varying systems;; System identification; LPV models","en","conference paper","Elsevier","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:14dc1cdd-618b-495f-a32a-d21209f47153","http://resolver.tudelft.nl/uuid:14dc1cdd-618b-495f-a32a-d21209f47153","3D surface-wave estimation and separation using a closed-loop approach","Ishiyama, T. (TU Delft Applied Geophysics and Petrophysics; INPEX Corporation); Blacquière, G. (TU Delft Applied Geophysics and Petrophysics); Verschuur, D.J. (TU Delft ImPhys/Acoustical Wavefield Imaging); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2016","Surface waves in seismic data are often dominant in a land or shallow-water environment. Separating them from primaries is of great importance either for removing them as noise for reservoir imaging and characterization or for extracting them as signal for near-surface characterization. However, their complex properties make the surface-wave separation significantly challenging in seismic processing. To address the challenges, we propose a method of three-dimensional surface-wave estimation and separation using an iterative closed-loop approach. The closed loop contains a relatively simple forward model of surface waves and adaptive subtraction of the forward-modelled surface waves from the observed surface waves, making it possible to evaluate the residual between them. In this approach, the surface-wave model is parameterized by the frequency-dependent slowness and source properties for each surface-wave mode. The optimal parameters are estimated in such a way that the residual is minimized and, consequently, this approach solves the inverse problem. Through real data examples, we demonstrate that the proposed method successfully estimates the surface waves and separates them out from the seismic data. In addition, it is demonstrated that our method can also be applied to undersampled, irregularly sampled, and blended seismic data.","Data processing; Inverse problem; Near surface; Noise; Parameter estimation; Separation; Surface wave","en","journal article","","","","","","","","2018-12-31","","","Applied Geophysics and Petrophysics","","",""
"uuid:848e3a93-afcf-4705-b473-addc0bfd489d","http://resolver.tudelft.nl/uuid:848e3a93-afcf-4705-b473-addc0bfd489d","Structure and Dynamics of a Model Discotic Organic Conducting Material","Zbiri, Mohamed (Institut Laue-Langevin); Haverkate, L.A. (TU Delft RST/Fundamental Aspects of Materials and Energy); Kearley, Gordon J. (Australian Nuclear Science and Technology Organisation); Johnson, Mark R. (Institut Laue-Langevin); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage)","","2016","Organic conducting materials exhibit promising functionalities, inducing hence a keen interest due to their potential use as a next generation photoconverters. However, unlike the more expensive inorganic analogues, the underlying properties that give rise to these advantages also cause organic materials to be inherently inefficient as photovoltaics. Understanding their properties at the microscopic level is a major step towards an efficient and targeted design. We probed the morphological and dynamical aspects of a model organic discotic liquid crystal material hexakis(n-hexyloxy)triphenylene (HAT6) by using neutron-based diffraction and quasielastic scattering techniques to gain deeper insights into structure and dynamics. The neutron measurements are accompanied, in a synergistic way, by molecular dynamics simulations for the sake of the analysis and interpretation of the observations.","","en","journal article","","","","","","","","","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:2c37578e-4d09-4296-939a-544a831d32db","http://resolver.tudelft.nl/uuid:2c37578e-4d09-4296-939a-544a831d32db","Synthesis and Single-Molecule Conductances of Neutral and Cationic Indenofluorene-Extended Tetrathiafulvalenes: Kondo Effect Molecules","Mansø, Mads (University of Copenhagen); Koole, M.A. (TU Delft Solutions; Kavli institute of nanoscience Delft); Mulder, M. (TU Delft ImPhys/Practicum support; Kavli institute of nanoscience Delft); Olavarria Contreras, I.J. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft); Andersen, Cecilie Lindholm (University of Copenhagen); Jevric, Martyn (University of Copenhagen); Broman, Søren Lindbæk (University of Copenhagen); Kadziola, Anders (University of Copenhagen); Hammerich, Ole (University of Copenhagen); van der Zant, H.S.J. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft); Nielsen, Mogens Brøndsted (University of Copenhagen)","","2016","Development of molecules that can switch between redox states with paired and unpaired electrons is important for molecular electronics and spintronics. In this work, a selection of redox-active indenofluorene-extended tetrathiafulvalenes (IF-TTFs) with thioacetate end groups was prepared from a readily obtainable dibromo-functionalized IF-TTF building block using palladium-catalyzed cross-coupling reactions, such as the Suzuki reaction. The end groups served as electrode anchoring groups for single-molecule conductance studies, and the molecules were subjected to mechanically controlled break-junction measurements with gold contacts and to low-bias charge transport measurements in gated three-terminal electromigration junctions. The neutral molecules showed clear conductance signatures, and somewhat surprisingly, we found that a meta-meta anchoring configuration gave a higher conductance than a para-meta configuration. We explain this behavior by ""through-space"" coupling between the gold electrode and the phenyl on which the anchoring group is attached. Upon charging the molecule in a gated junction, we found reproducibly a Kondo effect (zero-bias conductance) attributed to a net spin. Ready generation of radical cations was supported by cyclic voltammetry measurements, revealing stepwise formation of radical cation and dication species in solution. The first oxidation event was accompanied by association reactions as the appearance of the first oxidation peak was strongly concentration dependent.","","en","journal article","","","","","","","","","","","Solutions","","",""
"uuid:0958618c-2b49-424e-a481-833d0c41ab90","http://resolver.tudelft.nl/uuid:0958618c-2b49-424e-a481-833d0c41ab90","Use of Nano Seed Crystals to Control Peroxide Morphology in a Nonaqueous Li-O2 Battery","Ganapathy, S. (TU Delft RST/Fundamental Aspects of Materials and Energy); Li, Z. (TU Delft RST/Fundamental Aspects of Materials and Energy); Anastasaki, Maria S.; Basak, S. (TU Delft QN/Zandbergen Lab); Miao, X.F. (TU Delft RST/Fundamental Aspects of Materials and Energy); Goubitz, K. (TU Delft RST/Fundamental Aspects of Materials and Energy); Zandbergen, H.W. (TU Delft QN/Zandbergen Lab); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Wagemaker, M. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2016","The high theoretical energy density of Li-O2 batteries as required for electrification of transport has pushed Li-O2 research to the forefront. The poor cyclability of this system due to incomplete Li2O2 oxidation is one of the major hurdles to be crossed if it is ever to deliver a high reversible energy density. Here we present the use of nano seed crystallites to control the size and morphology of the Li2O2 crystals. The evolution of the Li2O2 lattice parameters during operando X-ray diffraction demonstrates that the hexagonal NiO nanoparticles added to the activated carbon electrode act as seed crystals for equiaxed growth of Li2O2, which is confirmed by scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM-EDX) elemental maps also showing preferential formation of Li2O2 on the NiO surface. Even small amounts of NiO (∼5 wt %) particles act as preferential sites for Li2O2 nucleation, effectively reducing the average size of the primary Li2O2 crystallites and promoting crystalline growth. This is supported by first principle calculations, which predict a low interfacial energy for the formation of NiO-Li2O2 interfaces. The eventual cell failure appears to be the consequence of electrolyte side reactions, indicating the necessity of more stable electrolytes. The demonstrated control of the Li2O2 crystallite growth by the rational selection of appropriate nano seed crystals appears to be a promising strategy to improve the reversibility of Li-air electrodes.","","en","journal article","","","","","","","","2017-08-01","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:6acc4e38-5e6e-4ab3-8f32-7aa868ca6f04","http://resolver.tudelft.nl/uuid:6acc4e38-5e6e-4ab3-8f32-7aa868ca6f04","Biological Nitrogen Removal in a Photosequencing Batch Reactor with an Algal-Nitrifying Bacterial Consortium and Anammox Granules","Manser, Nathan D. (University of South Florida Tampa); Wang, Meng (University of South Florida Tampa); Ergas, Sarina J. (University of South Florida Tampa); Mihelcic, James R. (University of South Florida Tampa); Mulder, Arnold (Amecon Environmental Consultancy); Van De Vossenberg, Jack (IHE Delft Institute for Water Education); van Lier, J.B. (TU Delft Sanitary Engineering; IHE Delft Institute for Water Education); Van Der Steen, Peter (IHE Delft Institute for Water Education)","","2016","This study demonstrates the feasibility of combining microalgae, ammonia-oxidizing bacteria (AOB), and Anammox in a photosequencing batch reactor. Alternating light and dark periods were applied to achieve biological nitrogen removal without mechanical aeration or external electron donor addition. This process is termed ALGAMMOX (algal anaerobic ammonium oxidation) and differs from the SHARON-Anammox process in that oxygen is generated during light periods through microalgal photosynthesis, replacing mechanical aeration. Results from bench-scale ALGAMMOX experiments with high-ammonia strength wastewater (COD/TN from 1 to 3) showed that influent ammonia was converted to nitrite during light periods at a rate of 7.0 mg of NH4 +-N L-1 h-1. Nitrite was subsequently reduced by an average of 82% during the dark (anoxic) periods due to Anammox activity. Further studies are needed to optimize the system to maximize nitrogen removal rates and to assess long-term process stability.","","en","journal article","","","","","","","","","","","Sanitary Engineering","","",""
"uuid:e1cbe76e-3dae-4c95-b915-0927e914ddf9","http://resolver.tudelft.nl/uuid:e1cbe76e-3dae-4c95-b915-0927e914ddf9","Full waveform inversion with an auxiliary bump functional","Bharadwaj, Pawan; Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics); Drijkoningen, G.G. (TU Delft Applied Geophysics and Petrophysics)","","2016","Least-squares inversion of seismic arrivals can provide remarkably detailed models of the Earth's subsurface. However, cycle skipping associated with these oscillatory arrivals is the main cause for local minima in the least-squares objective function. Therefore, it is often difficult for descent methods to converge to the solution without an accurate initial large-scale velocity estimate. The low frequencies in the arrivals, needed to update the large-scale components in the velocity model, are usually unreliable or absent. To overcome this difficulty, we propose a multi-objective inversion scheme that uses the conventional least-squares functional along with an auxiliary data-domain objective. As the auxiliary objective effectively replaces the seismic arrivals by bumps, we call it the bump functional. The bump functional minimization can be made far less sensitive to cycle skipping and can deal with multiple arrivals in the data. However, it can only be used as an auxiliary objective since it usually does not provide a unique model after minimization even when the regularized-least-squares functional has a unique global minimum and hence a unique solution. The role of the bump functional during the multi-objective inversion is to guide the optimization towards the global minimum by pulling the trapped solution out of the local minima associated with the least-squares functional whenever necessary. The computational complexity of the bump functional is equivalent to that of the least-squares functional. In this paper, we describe various characteristics of the bump functional using simple and illustrative numerical examples. We also demonstrate the effectiveness of the proposed multi-objective inversion scheme by considering more realistic examples. These include synthetic and field data from a cross-well experiment, surface-seismic synthetic data with reflections and synthetic data with refracted arrivals at long offsets.","Numerical solutions; Inverse theory; Tomography; Non-linear differential equations; Seismic tomography","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:4fc109b7-f7bf-46be-88ba-b83c4c2fa49a","http://resolver.tudelft.nl/uuid:4fc109b7-f7bf-46be-88ba-b83c4c2fa49a","Hack The Government!: Empowering Citizens to Make Meaningful Use of Open Data","Molinari, F (Politecnico di Milano); Concilio, Grazia (Politecnico di Milano); Mulder, I. (TU Delft Design Conceptualization and Communication); Klitgaard Torntoft, Louise (Aalborg University); Aguilar, Marc (4I2CAT Foundation)","Parycek, Peter (editor); Edelmann, Noella (editor)","2016","Citizens’ use of Open Data is often limited to the use of apps. The design of the (app based) public service as well as the interpretation of the data is done for them. The organization of local hackathons can promote citizens’ data literacy and better use of available
Open Data for service transformation purposes. This promises to nicely combine citizen intelligence with participatory innovation with and by public service beneficiaries as the “next wave” of inclusive (e-)Government practice. In the proposed workshop, we simulate the
organization and dynamics of a Hackathon based on the evidence at hand.","hackathons; Open Data; public service innovation; inclusive Government; citizen participation","en","conference paper","Danube University Krems","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:b66b443a-c834-4d31-a88d-be15fd5b0a66","http://resolver.tudelft.nl/uuid:b66b443a-c834-4d31-a88d-be15fd5b0a66","Improving the accuracy of mass-lumped finite-elements in the first-order formulation of the wave equation by defect correction","Shamasundara, R.; Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2016","Finite-element discretizations of the acoustic wave equation in the time domain often employ mass lumping to avoid the cost of inverting a large sparse mass matrix. For the second-order formulation of the wave equation, mass lumping on Legendre–Gauss–Lobatto points does not harm the accuracy. Here, we consider a first-order formulation of the wave equation. In that case, the numerical dispersion for odd-degree polynomials exhibits super-convergence with a consistent mass matrix but mass lumping destroys that property. We consider defect correction as a means to restore the accuracy, in which the consistent mass matrix is approximately inverted using the lumped one as preconditioner. For the lowest-degree element on a uniform mesh, fourth-order accuracy in 1D can be obtained with just a single iteration of defect correction.
The numerical dispersion curve describes the error in the eigenvalues of the discrete set of equations. However, the error in the eigenvectors also play a role, in two ways. For polynomial degrees above one and when considering a 1-D mesh with constant element size and constant material properties, a number of modes, equal to the maximum polynomial degree, are coupled. One of these is the correct physical mode that should approximate the true eigenfunction of the operator, the other are spurious and should have a small amplitude when the true eigenfunction is projected onto them. We analyze the behaviour of this error as a function of the normalized wavenumber in the form of the leading terms in its series expansion and find that this error exceeds the dispersion error, except for the lowest degree where the eigenvector error is zero. Numerical 1-D tests confirm this behaviour.
We briefly analyze the 2-D case, where the lowest-degree polynomial also appears to provide fourth-order accuracy with defect correction, if the grid of squares or triangles is highly regular and material properties are constant.
In seismic exploration, the delineation of large bodies with hard exterior contrasts but nearly constant interior properties is a challenge. Examples include salt diapirs, salt slabs, anhydrite or basalt layers. Salt geometries are of particular interest because they often have hydrocarbon reservoirs on their sides or underneath. This papers introduces a parametric level-set method for the reconstruction of such geometries in seismic full-waveform inversion (FWI). The level-set determines the outline of the salt geometry and evolves during the inversion in terms of its underlying parameters. For the latter, we employ Gaussian radial basis functions that can represent a large class of shapes with a small number of parameters. This keeps the dimensionality of the inverse problem small, which makes it easier to solve. First tests on a simple 2-D square box model show dramatic improvements over classic FWI.","fractures; inversion; reflection; AVO/AVA; fluid","en","conference paper","SEG","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:fb196942-e843-458f-bfae-eba86f750887","http://resolver.tudelft.nl/uuid:fb196942-e843-458f-bfae-eba86f750887","A Shear-Wave Seismic System to Look Ahead of a Tunnel Boring Machine","Bharadwaj, Pawan; Drijkoningen, G.G. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics); Tscharner, Thomas; Jenneskens, Rob","","2016","The Earth’s properties, composition and structure ahead of a tunnel boring machine (TBM) should be mapped for hazard assessment during excavation. We study the use of seismic-exploration techniques for this purpose. We focus on a seismic system for soft soils, where shear waves are better and easier to interpret than compressional waves, as has been shown over the last decade. The system is intended to be deployed on the machine’s cutter head, with a few seismic sources and sufficiently many seismic sensors to tackle spatial variability and noise characteristics. An important property of the newly developed system is its ability to process data with very little human interaction. Images need to be available in near real time, without human interactions slowing down the imaging process. This can be achieved by employing Full Waveform Inversion, which minimizes the difference between modeled and observed data. Because this method may suffer from local minima in the cost function if the data lack low-frequency information, we employ a dedicated seismic source that can generate sufficiently low frequencies for the relevant length scales. With data acquired in a number of field settings that mimic realistic TBM configurations, we show that the designed seismic system can successfully look ahead of the TBM and offers a valuable capability to support decision-making during tunnel excavation.","","en","conference paper","Society for mining, metallurgy & exploration","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:8668d9a4-367c-4f6b-b2b5-6759ec33bb79","http://resolver.tudelft.nl/uuid:8668d9a4-367c-4f6b-b2b5-6759ec33bb79","Should We Use the First- or Second-order Formulation with Spectral Elements for Seismic Modelling?","Shamasundar, R. (TU Delft Applied Geophysics and Petrophysics); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2016","The second-order formulation of the wave equation is often used for spectral-element discretizations. For some applications, however, a first-order formulation may be desirable. It can, in theory, provide much better accuracy in terms of numerical dispersion if the consistent mass matrix is used and the degree of the polynomial basis functions is odd. However, we find in the 1-D case that the eigenvector errors for elements of degree higher than one are larger for the first-order than for the second-order formulation. These errors measure the unwanted cross talk between the different eigenmodes. Since they are absent for the lowest degree, that linear element may perform better in the first-order formulation if the consistent mass matrix is inverted. The latter may be avoided by using one or two defect-correction iterations. Numerical experiments on triangles confirm the superior accuracy of the first-order formulation. However, with a delta-function point source, a large amount of numerical noise is generated. Although this can be avoided by a smoother source representation, its higher cost and the increased susceptibility to numerical noise make the second-order formulation more attractive.","","en","conference paper","EAGE","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:16611f85-c7d7-4ede-a34e-17279feaace8","http://resolver.tudelft.nl/uuid:16611f85-c7d7-4ede-a34e-17279feaace8","A fast 3-D free-surface topography method for acoustic full-waveform inversion","Huiskes, M.J.; Plessix, RE; Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2016","We propose a finite-difference scheme for the simulation of seismic waves interacting with 3-D freesurface topography. The intended application is velocity model building by acoustic full-waveform inversion (FWI). The scheme follows an immersed boundary approach for wave equations in the firstorder stress-velocity formulation, discretized on a standard staggered grid. Our scheme employs modified 1-D stencils rather than a full 3-D field wavefield extension at the free surface. Although this decreases the accuracy, it improves the scheme's simplicity and robustness. To avoid stability problems, points close to the zero-pressure boundary must be excluded. The scheme, and its adjoint, have been tested by tilted geometry tests and by comparison to a finite-element method. We present a first test result of full-waveform inversion with the new scheme.","","en","conference paper","EAGE","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:3e78732a-bce9-4489-b22e-d1c4bd857f72","http://resolver.tudelft.nl/uuid:3e78732a-bce9-4489-b22e-d1c4bd857f72","Modelling an angular accelerometer using frequency-response measurements","Jatiningrum, D. (TU Delft Control & Simulation); de Visser, C.C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2016","A characterization of an angular accelerometer sensor is performed with a frequency- response experiment. To assess angular accelerometer dynamic properties, a position-based calibration table is utilized to provide the excitation input. The angular accelerometer specifications and calibration table limitations dfine a constrained test envelope for this particular setup. Measurement are obtained for a number of constant accelerations and varied with frequency. Analysis of the input-output relation in the frequency-domain leads to a frequency-response function model of the angular accelerometer. Time-domain data are used to validate the frequency-response model. A fourth-order structure is then preferred as the transfer-function for the 400 deg=s acceleration, with a 99:02 %fit. Besides representing the angular accelerometer dynamics, the angular accelerometer model is es- sential for the design of fault-tolerant light control system.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","harvest AIAA 2016-1139","","2017-01-31","","","Control & Simulation","","",""
"uuid:ea4df79b-7455-48db-82e3-e46f28cd91d2","http://resolver.tudelft.nl/uuid:ea4df79b-7455-48db-82e3-e46f28cd91d2","Impact of Nanostructuring on the Phase Behavior of Insertion Materials: The Hydrogenation Kinetics of a Magnesium Thin Film","Bannenberg, L.J. (TU Delft RST/Neutron and Positron Methods in Materials); Schreuders, H. (TU Delft ChemE/Materials for Energy Conversion and Storage); van Eijck, L. (TU Delft RST/Neutron and Positron Methods in Materials); Heringa, J.R. (TU Delft RST/Fundamental Aspects of Materials and Energy); Steinke, N.J. (ISIS, Rutherford Appleton Laboratory); Dalgliesh, R.M. (ISIS, Rutherford Appleton Laboratory); Dam, B. (TU Delft ChemE/Materials for Energy Conversion and Storage); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage); van Well, A.A. (TU Delft RST/Neutron and Positron Methods in Materials)","","2016","Nanostructuring is widely applied in both battery and hydrogen materials to improve the performance of these materials as energy carriers. Nanostructuring changes the diffusion length as well as the thermodynamics of materials. We studied the impact of nanostructuring on the hydrogenation in a model system consisting of a thin film of magnesium sandwiched between two titanium layers and capped with palladium. While we verified optically the coexistence of the metallic α-MgDx and the insulating β-MgD2–y phase, neutron reflectometry shows significant deviations from the thermodynamic solubility limits in bulk magnesium during the phase transformation. This suggests that the kinetics of the phase transformation in nanostructured battery and hydrogen storage systems is enhanced not only as a result of the reduced length scale but also due to the increased solubility in the parent phases.","","en","journal article","","","","","","Accepted Author Manuscript","","2017-05-03","","","RST/Neutron and Positron Methods in Materials","","",""
"uuid:6f121ea1-a33c-4fa5-945f-f28c4bbe5011","http://resolver.tudelft.nl/uuid:6f121ea1-a33c-4fa5-945f-f28c4bbe5011","Urban symbiosis: A new paradigm in the shift towards post-carbon cities","Mulder, K.F. (TU Delft Environmental Technology and Design; TU Delft Organisation & Governance)","","2016","The metabolic flows of cities have to be reduced. Thus far, efforts have been mainly directed to providing the city with renewable resources, diminish resource consumption, and/or reuse the wastes and emissions. The dense fabric of urban infrastructures does not only provide a high level of services. By the proximity of infrastructures symbiosis might be created between them. This urban symbiosis might lead to a considerable reduction of resource consumption and/or carbon- and other emissions of all systems involved. However, developing symbiosis between urban infrastructures implies that the owners/operators of the infrastructures are able to align their interests too. This might be problematic as infrastructure operators developed a culture of autonomy. Moreover, they are nowadays owned by various public and private entities that pursue different agendas. The top down planning model of infrastructures appears to be at the end of its life cycle; citizens, businesses and NGO’s request participation. Early participation, using future methods and workshops might contribute to align actors for promising urban symbiosis options. The paper analyses barriers in developing urban symbiosis and sketches strategies how to deal with them. It uses the example of urban waste water systems to sketch strategies to develop symbiosis between urban infrastructures.","urban symbiosis; urban infrastructure; systems innovation; long term visioning; sewage systems","en","journal article","","","","","","","","","","","Environmental Technology and Design","","",""
"uuid:72194627-8829-48ff-a81d-1d5a599f3405","http://resolver.tudelft.nl/uuid:72194627-8829-48ff-a81d-1d5a599f3405","Organising urban symbiosis projects","Vernay, A.L. (Grenoble Ecole de Management); Mulder, K.F. (TU Delft Environmental Technology and Design; The Hague University of Applied Sciences)","","2016","Urban symbiosis is a strategy to create a more efficient metabolism of cities. However, urban symbiosis requires the integration of different systems, which is hard to achieve. Actors involved in existing systems can hardly develop ‘the bridges’ that are required to connect the thus far unrelated worlds of pre-existing systems. This paper analyses two cases of urban symbiosis and focusses on the process of building new actor networks. Urban symbiosis projects are generally complex and involve various stakeholders. The authors conclude that the introduction of additional actors or an additional institutional framework might be an effective means to create bridges between actors that could facilitate a more efficient metabolism of cities.","infrastructure planning; renewable energy; sewage treatment & disposal","en","journal article","","","","","","","","2016-11-05","","","Environmental Technology and Design","","",""
"uuid:6cd67b83-ef05-4882-8a44-feb9f9f2e21d","http://resolver.tudelft.nl/uuid:6cd67b83-ef05-4882-8a44-feb9f9f2e21d","Motion Simulator 2-Axis Input Design for Angular Accelerometer Calibration","Jatiningrum, D. (TU Delft Control & Simulation); de Visser, C.C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2016","The calibration of Angular Accelerometers requires a controlled test with a known acceleration profile. However, current turn-tables have been designed primarily for generating a constant rotational velocity. To generate a profile with varying angular acceleration we propose using constant rotational velocity on the two axes of a 2-axes motion simulator. The proposed sequence was developed to obtain the required rotational acceleration signal quality using only rotational velocity input. The identified pattern is applied to an envelope of test conditions, resulting in test matrix. This method provides an alternative means to generate inputs that can be used to calibrate angular accelerometers using calibration hardware that is not primarily designed to provide accurate acceleration inputs.
We wish to have this document be a summary of the workshop, consisting of snapshots of the discussions that went into several directions along citizen engagement, the role of the government, how to scale up interventions, how to foster systemic change and so forth.
The about 20 people present at the workshop offered diverse perspectives on the agenda. The debates along certain topics were sometimes heated or controversial, but “moderate provocation” did trigger further depth in reflection.
This document is not aimed at being conclusive, but to be a goto
reference to recap what happened during the workshop. Last, but not least, we would like to thank again the participants who had been at the workshop and played along with us. We learned a lot, and we hope that you did too.","","en","book","Delft University of Technology","","","","","","","","","","Design Conceptualization and Communication","","",""
"uuid:da2d9824-cc05-4df3-aa58-83bce1f88550","http://resolver.tudelft.nl/uuid:da2d9824-cc05-4df3-aa58-83bce1f88550","Ecological Interface Design: Sensor Failure Diagnosis in Air Traffic Control","Bijsterbosch, V.A.; Borst, C. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); van Paassen, M.M. (TU Delft Control & Simulation)","","2016","Future air traffic control will have to rely on more advanced automation in order to support controllers in their job of safely controlling increased traffic volumes. A prerequisite for the success of such automation is that the underlying data driving it is reliable. Current technology, however, still warrants human supervision in coping with (data) uncertainties and consequently in judging the validity of machine decisions. In this paper the Ecological Interface Design (EID) framework is explored to assist controllers in fault diagnosis using a prototype ecological interface (called the Solution Space Diagram) for tactical conict detection and resolution in the horizontal plane. Results from a human-in-the-loop experiment with sixteen participants indicate that the ecological interface with explicit presentation of the means-ends relations between higher-level functional goals and lower-level physical objects (i.e., aircraft) enables improved sensor failure detection. Especially in high complexity scenarios, this feature had a positive impact on failure detection performance.","Ecological Interface Design; Air Traffic Control; Automation; Supervisory Control; Sensor Failure; Decision-Making","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:ad652b50-4e6c-44bb-8ed6-f7bd3ab7d517","http://resolver.tudelft.nl/uuid:ad652b50-4e6c-44bb-8ed6-f7bd3ab7d517","Cross-sector transferability of metrics for air traffic controller workload","Abdul Rahman, S.M.B.; Borst, C. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2016","Air traffc controller workload is an important impediment to air transport growth. Several approaches exist that aim to better understand the causes for workload, and models have been derived to predict workload in new operational settings. These methods often relate workload to the diffculty, or complexity, that an average controller would have to safely manage all traffc in a sector with a particular traffc demand. In this paper, several of these complexity-based metrics for workload will be compared. Of special interest is whether the complexity measures transfer from one sector design to another. That is, does a metric that is well-tuned to predict workload for controllers working in one sector, also predict the workload for another group of controllers active in a different sector? Results from a human-in-the-loop experiment show that a solution space-based metric, which requires no tuning or weighing at all, has the highest correlations with subjectively reported workload, and also yields the best workload predictions across different controller groups and sectors.","Air traffc control; taskload; mental workload; supervisory control","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:65509837-b963-4895-9261-9a0afbfe38e1","http://resolver.tudelft.nl/uuid:65509837-b963-4895-9261-9a0afbfe38e1","The Effects of Yaw and Sway Motion Cues in Curve Driving Simulation","Lakerveld, P.R.; Damveld, H.J. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); van der El, K.; van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2016","This paper investigates the importance of yaw and sway motion cues in curve driving simulation. While such motion cues are known to enhance simulation realism, their function in supporting realistic driver behavior in simulators is still largely unknown. A human-in-the-loop curve driving experiment was performed in the SIMONA Research Simulator at TU Delft, in which eight participants were asked to follow a winding road’s center-line, while being subject to wind disturbances. Four motion conditions were tested: 1) no motion, 2) yaw only, 3) sway only, and 4) both yaw and sway; each was tested with 5 m and 100 m road preview for correspondence with earlier work. Results show that visual road preview is essential for adequate road-following. Although the effects of yaw and sway cues are much smaller, sway motion feedback allows for improved disturbance-rejection performance, while yaw motion feedback results in reduced control activity. These distinctly different effects suggest that both motion cues are important for evoking realistic driving behavior in simulators.","Driving simulation; driver behavior; motion cueing; curve driving","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:d7ffc4a0-00a1-46ea-baa3-8d9d4890633f","http://resolver.tudelft.nl/uuid:d7ffc4a0-00a1-46ea-baa3-8d9d4890633f","Ecological Interface for Collaboration of Multiple UAVs in Remote Areas","van Lochem, S.; Borst, C. (TU Delft Control & Simulation); de Croon, G.C.H.E. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2016","Unmanned Aerial Vehicles (UAVs) can be used to access remote areas, e.g., for surveillance missions. Collaboration between them can help overcome communication constraints by building airborne relay networks that allow beyond line of sight communication. This research investigates whether a single human operator can supervise multiple UAVs in a collaborative surveillance task under communication constraints. We designed an ecological interface to support operators in their task and increase system flexibility. A preliminary humanin-the-loop study was done to investigate operator task performance and evaluate interface components. It was shown that operators are able to successfully operate surveillance missions under communication- and battery constraints. Participants did, however, not succeed to do this without separation conflicts and communication losses, which indicates that the interface lacks elements representing endurance and separation assurance. To an extent, the interface design turned out to be scalable, with a few remaining visualizations that cause clutter for large numbers of UAVs. More advanced ways of displaying information on request and grouping of select information is warranted to further improve the interface.","human-machine interface; supervisory control; ecological interface design","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:095bb1e1-6e79-4291-9df0-58047e4d30b9","http://resolver.tudelft.nl/uuid:095bb1e1-6e79-4291-9df0-58047e4d30b9","Constraints in Identification of Multi-Loop Feedforward Human Control Models","Drop, F.M. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); Bülthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics)","","2016","The human controller (HC) can greatly improve target-tracking performance by utilizing a feedforward operation on the target signal, in addition to a feedback response. System identification methods are used to determine the correct HC model structure: purely feedback or a combined feedforward/feedback model. In this paper, we investigate three central issues that complicate this objective. First, the identification method should not require prior assumptions regarding the dynamics of the feedforward and feedback components. Second, severe biases might be introduced by high levels of noise in the data measured under closed-loop conditions. To address the first two issues, we will consider two identification methods that make use of linear ARX models: the classic direct method and the two-stage indirect method of van den Hof and Schrama (1993). Third, model complexity should be considered in the selection of the ‘best’ ARX model to prevent ‘false-positive’ feedforward identification. Various model selection criteria, that make an explicit trade-off between model quality and model complexity, are considered. Based on computer simulations with a HC model, we conclude that 1) the direct method provides more accurate estimates in the frequency range of interest, and 2) existing model selection criteria do not prevent false-positive feedforward identification.","cybernetics; manual control; dynamic behaviour; modeling","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:4c5f7c8d-a7ee-4843-9cfa-6ec1f22cbe41","http://resolver.tudelft.nl/uuid:4c5f7c8d-a7ee-4843-9cfa-6ec1f22cbe41","Design and evaluation of a Flight Envelope Protection haptic feedback system","Ellerbroek, Joost (TU Delft Control & Simulation); Rodriguez Martin, M.J.M.; Lombaerts, T (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","","2016","This paper describes the design and evaluation of a shared control, haptic feedback system to communicate Flight Envelope Protection System intent. The concept uses a combination of stiffness feedback and vibration to communicate proximity of the aircraft state to flight envelope boundaries. In addition, a stick center shift can be applied by the envelope protection system to cooperatively perform corrective actions in case of severe excursions of the envelope margins. Results from the evaluation experiment show improved performance with haptic feedback in both scenarios. Workload ratings were unaffected. Pilot opinion was unanimously positive, especially with regard to the combination of stiffness feedback and vibration cues.","shared control; haptics; flight envelope protection","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:a998f597-3cd8-4040-a704-cd44fc75b622","http://resolver.tudelft.nl/uuid:a998f597-3cd8-4040-a704-cd44fc75b622","The Predictability of a Target Signal Affects Manual Feedforward Control","Drop, F.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations); Bülthoff, Heinrich H. (Max Planck Institute for Biological Cybernetics); de Vries, R. (Max Planck Institute for Biological Cybernetics)","","2016","In the manual control of a dynamic system, the human controller (HC) is often required to follow a visible and predictable reference path. Using the predictable aspect of a reference signal, through applying feedforward control, the HC can significantly improve performance as compared to a purely feedback control strategy. A proper definition of a signal’s predictability, however, is never given in literature. This paper investigates the predictability of a sum-of-sinusoids target signal, as a function of the number of sinusoid components and the fact whether the sinusoid frequencies are harmonic, or not. A human-in-the-loop experiment was done, with target signals varying for these two signal characteristics. A combined feedback-feedforward HC model was identified and parameters were estimated. It was found that for all experimental conditions, subjects used a feedforward strategy. Results further showed thatsubjects were able to perform better for harmonic signals as compared to non-harmonic signals, for signals with roughly the same frequency content.","cybernetics; manual control; dynamic behaviour; modeling","en","journal article","","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:555d79b3-f72e-4f68-994a-c9fae31f2841","http://resolver.tudelft.nl/uuid:555d79b3-f72e-4f68-994a-c9fae31f2841","Interactions of Outside Visual Cues and Motion Cueing Settings in Yaw Tracking","Peterse, H.P.M.; Pool, D.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2016","Knowledge of how human operators’ tracking behavior is affected by simulator motion cueing settings is of great value for flight simulator design and fidelity evaluations. Previous studies have revealed strong effects of degraded motion cueing quality on human operator control behavior in compensatory tracking, but the presented visual cues in such studies are often not consistent with what operators perceive in more realistic settings, as they typically do not include the visual cues provided by the out-of-the-window view from their vehicle. This paper aims to investigate the effects of the interaction of such outside visual cues and of motion cueing settings on human operator behavior. Thereto, an experiment in a flight simulator was conducted in which participants performed a yaw-axis target-following disturbance-rejection tracking task. The presence of an outside visual scene and simulator motion feedback quality were varied independently. In the experiment, motion cues were either absent or presented with varying attenuation induced by changing the break frequency of a first-order high-pass yaw motion filter. The results indicate a strong effect of outside visual cues on human operator control behavior in the absence of motion feedback, which is comparable to the measured effect of motion feedback. Overall, human operator control behavior was found to be less affected by varying motion cueing settings when the outside visual cues were available in parallel.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:a1e5745e-5e89-44be-a889-c46c69315989","http://resolver.tudelft.nl/uuid:a1e5745e-5e89-44be-a889-c46c69315989","Objective ARX Model Order Selection for Multi-Channel Human Operator Identification","Roggenkämper, N; Pool, D.M. (TU Delft Control & Simulation); Drop, F.M. (TU Delft Control & Simulation); van Paassen, M.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Simulation)","","2016","In manual control, the human operator primarily responds to visual inputs but may elect to make use of other available feedback paths such as physical motion, adopting a multi-channel control strategy. Hu- man operator identification procedures generally require a priori selection of the model structure, which can be problematic as the exact feedback organization operators adopt is not always clear in advance. This pa- per evaluates a novel method for objectively detecting the presence of additional human operator feedback responses in control tasks with multiple inputs. The approach makes use of linear-time invariant ARX mod- els for system identification, combined with an objective model selection criterion. To test the method, an experiment was conducted in which participants performed a compensatory yaw attitude tracking task in a moving-base flight simulator, with varying motion cueing settings. In addition, a pursuit tracking condition without motion feedback was tested. For all conditions, the objective ARX model-based identification method was used to verify the presence of a possible additional human operator output feedback response. With ap- propriate tuning of the penalty on model complexity in the model selection criterion, the methodology proved successful in correctly identifying the additional operator responses in experimental conditions that contained no motion or high-quality motion feedback. With low-fidelity motion feedback or a pursuit display, the results suggest that no consistent feedback response is achieved by the participants. The approach was substantiated with offline Monte Carlo simulations, which show strong correlation with the obtained experiment results.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Control & Simulation","","",""
"uuid:f0fe4aa3-c957-482c-9b19-ad28df9bb6cb","http://resolver.tudelft.nl/uuid:f0fe4aa3-c957-482c-9b19-ad28df9bb6cb","Seismoelectromagnetic homogeneous space Green's functions","Slob, E.C. (TU Delft Applied Geophysics and Petrophysics); Mulder, M.","","2016","We have developed explicit expressions and the corresponding computer code for all homogeneous space Green’s functions for coupled electromagnetic fields and poroelastic waves. The Green’s functions are derived from the basic equations in closed form in the wavenumber- and space-frequency domains. They are given for point sources of any type. This adds several Green’s functions to what has been published before. These Green’s functions can be used in integral equation formulations, for numerical model validation, and for studying earthquake-related electrokinetic effects. The wavenumber domain code for all Green’s functions is given with the numerical test on the basic equations to demonstrate correctness. The numerical codes to compute them in the space-frequency domain are also given. A numerical inverse fast Fourier transformation routine is used to provide space-time domain results. At seismic frequencies, the fast P-wave is radiated with the largest amplitude in all fields, except for the magnetic fields where no P-waves are generated. At ultrasonic frequencies and in the particle and filtration velocity fields generated by an electric current source, the slow P-wave has the strongest amplitude. In the filtration velocity and particle velocity, the slow P-wave is, respectively, three orders and one order of magnitude stronger than the fast P-wave.","electromagnetics; viscoelastic; wave propagation; radiation; 3D","en","journal article","","","","","","","","2018-06-14","","","Applied Geophysics and Petrophysics","","",""
"uuid:e4bbbf0e-f348-4706-b68e-3e4b1e714820","http://resolver.tudelft.nl/uuid:e4bbbf0e-f348-4706-b68e-3e4b1e714820","A Symmetric Interior Penalty Discontinuous Galerkin Method with Local Time Stepping for Anisotropic Elasticity Problems","Geevers, Sjoerd (University of Twente); van der Vegt, Jaap (University of Twente); Mulder, W.A. (TU Delft Applied Geophysics and Petrophysics; Shell Global Solutions International B.V.)","","2016","We present and analyse a Symmetric Interior Penalty Discontinuous Galerkin (SIPDG) method combined with an explicit hybrid Local Time Stepping (LTS) scheme for solving seismic wave problems in heterogeneous anisotropic elastic media. The discontinuous Galerkin method allows for local adjustment of the mesh size and approximation order, and can deal with unstructured non-conforming meshes of mixed types. Furthermore, when using orthogonal basis functions and an explicit time integration scheme, the method becomes fully explicit and inherently parallel, making it an attractive method for seismic applications involving large three-dimensional domains, sharp material contrasts, and detailed internal structures.","","en","abstract","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:6c25c952-5b84-4f8f-a698-dd866dc92d5d","http://resolver.tudelft.nl/uuid:6c25c952-5b84-4f8f-a698-dd866dc92d5d","Composition dependent properties of graphene (oxide)-alginate biopolymer nanocomposites","Vilcinskas, K. (TU Delft ChemE/Advanced Soft Matter); Jansen, K.M.B. (TU Delft Emerging Materials); Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage); Picken, S.J. (TU Delft ChemE/Advanced Soft Matter); Koper, G.J.M. (TU Delft ChemE/Advanced Soft Matter)","","2016","We report on the thermal, electrical, and mechanical properties of alginate biopolymer nanocomposites prepared by solution casting with various amounts of graphene oxide (GO) or reduced GO (rGO). Our data shows that the thermal stability of alginate nanocomposites can be improved by the introduction of cross-linking through divalent metal cations, albeit that under these conditions little influence by the amount of rGO remains. On the other hand, the electrical conductivity of divalent metal ion cross-linked-rGO improves approximately 10 orders of magnitude with increasing weight fraction of rGO, whereas it declines for sodium alginate-GO composites. In addition, storage moduli and glass to rubber transition temperatures show strong composition dependence as a consequence of complex interactions of the ions with both polymer and filler. We propose a mechanical model that allows for the accurate prediction of reinforcement by GO sheets in sodium alginate-GO composites taking into account the orientational order of the sheets. Creep tests reveal the complex nature of multiple stress relaxation mechanisms in the nanocomposites although the stretched exponential Burgers' model accurately describes short time creep compliance.","","en","journal article","","","","","","","","2017-09-11","","","ChemE/Advanced Soft Matter","","",""
"uuid:fe7dd7a4-0ff0-4abc-a7d1-efd3346cbc0b","http://resolver.tudelft.nl/uuid:fe7dd7a4-0ff0-4abc-a7d1-efd3346cbc0b","Human crossfeed in dual-axis manual control with motion feedback","Barendswaard, S. (TU Delft Biomechatronics & Human-Machine Control); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Sawaragi, T. (editor)","2016","While many realistic manual control tasks require human operators to control multiple degrees-of-freedomsimultaneously, our understanding of such multi-axis manual control has not moved far beyond considering it simply as the control of multiple fully-independent axes. This investigation aims to further our understanding of multi-axis control by focusing on one phenomenon that is known to occur in such tasks: crossfeed. Crossfeed occurs when operators’ inputs in one controlled axis feed into another controlled degree-of-freedom, thereby affecting overall control performance. A human-in-the-loop experiment, in which operators performed a dual-axis aircraft roll and pitch tracking task with physical motion feedback, was conducted in the SIMONA Research Simulator at TU Delft. Three conditions were tested: the full dual-axis control task, supplemented with reference single-axis roll and pitch tasks. Through the use of independent target and disturbance forcing function signals in both controlled axes, we were able to detect the presence of crossfeed in this dual-axis task from spectral analysis. Furthermore, these signals facilitated the objective identification of the dynamics of the crossfeed contribution, in parallel with estimating operators visual and motion responses. The crossfeed dynamics were found to resemble the well-known dynamics of human operators’ visual responses. The crossfeed contribution was found to explain up to 20% of the measured control inputs, thereby indicating that crossfeed can be a factor of significance in multi-axis manual control.","multi-axis control; manual control; human operator modeling; crossfeed","en","conference paper","Elsevier","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:84fbd30a-0139-4fce-b754-79824b18243c","http://resolver.tudelft.nl/uuid:84fbd30a-0139-4fce-b754-79824b18243c","Design of test signals for identification of neuromuscular admittance","Bhoelai, A.K.; van Paassen, M.M. (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Biomechatronics & Human-Machine Control); Mulder, Max (TU Delft Control & Operations)","Sawaragi, T. (editor)","2016","The human neuromuscular system can be seen as a versatile and extremely adaptive actuator. Through co-contraction and reex modulation, the properties of the neuromuscular system can be modified, leading to a change in movement response to externally applied forces. These properties are normally expressed in the form of the neuromuscular admittance. In a series of standard tasks, the force-, relax-, and position-task admittance of the neuromuscular system can be identified. However, the test signals used in these tasks can also limit the range of reex adaptation possible and wrong choice can create a phenomenon analogous to cross-over regression in manual control tasks, and force the human to use only a limited range of the possible reex adaptation. This paper presents a systematic investigation, through a model study, of the inuence of test signals on the range of reex adaptation. For this, criteria for test signal acceptability have been developed. The method is applied to the currently used test signals consisting of a high and a low shelf, and enables the selection of the high shelf bandwidth.","","en","conference paper","Elsevier","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:a5708dfd-a790-436b-905a-d6ec62a514a5","http://resolver.tudelft.nl/uuid:a5708dfd-a790-436b-905a-d6ec62a514a5","Fundamental issues in manual control cybernetics","Mulder, Max (TU Delft Control & Operations); Pool, D.M. (TU Delft Control & Simulation); Abbink, D.A. (TU Delft Biomechatronics & Human-Machine Control); Boer, E.R. (TU Delft Biomechatronics & Human-Machine Control); van Paassen, M.M. (TU Delft Control & Simulation)","Sawaragi, T. (editor)","2016","Manual control cybernetics aims to understand and describe how humans control vehicles and devices, such that more effective human-machine interfaces can be designed. Current cybernetics theory is primarily based on technology and analysis methods developed in the 1960s and has shown to be limited in its capability to capture the full breadth of human cognition and control. This paper summarizes some of the main fundamental limitations in cybernetics and provides a possible road-map to advance the theory and its applications. Central in this agenda will be a shift from the current linear time-invariant modeling approach, to the use of linear parameter-varying system models. Recent progress in identification methods of these latter models may allow us, for the first time, to mathematically model and identify time-varying, adaptive human control, opening up many opportunities to systematically optimize our human control interfaces and training. New foundations for cybernetics will impact all domains that involve humans in manual and semi-automatic control.","cybernetics; manual control; dynamic behaviour; modeling","en","conference paper","Elsevier","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:e79321e7-fca6-4d39-89f4-9633d32ffe36","http://resolver.tudelft.nl/uuid:e79321e7-fca6-4d39-89f4-9633d32ffe36","Relating Eye Activity Measures to Human Controller Remnant Characteristics","Popovici, A (San José State University); Zaal, P.M.T. (TU Delft Control & Simulation); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Sawaragi, T (editor)","2016","This study attempts to partially explain the characteristics of the human perceptual remnant, following Levison’s representation of the remnant as an equivalent observation noise. Eye activity parameters are recorded using an eye tracker in two compensatory tracking tasks in which the visual information is presented using either a first or second-order visual stimulus. Differences in the two conditions between remnant characteristics, eye activity measures and human operator model parameters are analyzed, using preliminary data from three subjects. Preliminary results show that the second-order visual stimulus introduces changes in both eye activity and remnant model parameters. Although high correlations are observed between remnant gain and blink frequency, between remnant break frequency and eye opening amplitude, and between remnant power and pupil diameter, a definitive conclusion about the perceptual remnant - eye activity characteristics relation cannot be drawn due to the small sample size of the obtained data. This preliminary study is a first step in identifying possible physiological parameters that affect the perceptual human remnant.","human remnant; manual control; eye tracking; visual stimulus","en","conference paper","Elsevier","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:f43b6a7b-77c8-493c-ba3d-6137d8e6d587","http://resolver.tudelft.nl/uuid:f43b6a7b-77c8-493c-ba3d-6137d8e6d587","Effects of preview time on human control behavior in rate tracking tasks","van der El, K.; Barendswaard, S. (TU Delft Biomechatronics & Human-Machine Control); Pool, D.M. (TU Delft Control & Simulation); Mulder, Max (TU Delft Control & Operations)","Sawaragi, T (editor)","2016","In many practical control tasks, human controllers (HC) can preview the trajectory they must follow in the near future. This paper investigates the effects of the length of previewed target trajectory, or preview time, on HC behavior in rate tracking tasks. To do so, a human-in-the-loop experiment was performed, consisting of a combined target-tracking and disturbance-rejection task. Between conditions the preview time was varied between 0, 0.1, 0.25 0.5 0.75 or 1 s, capturing the complete human control-behavioral adaptation from zero- to full-preview tasks, where the performance remains constant. The measurements were analyzed by fitting a HC model for preview tracking tasks to the data. Results show that optimal performance is attained when the displayed preview time is higher than 0.5 s. When the preview time increases, subjects exhibit more phase lead in their target response dynamics. They respond to a single point on the target ahead when the preview time is below 0.5 s and generally to two different points when more preview is displayed. As the model tightly fits to the measurement data, its validity is extended to different preview times","Target Tracking; manual control; Preview; Parameter Estimation; Human Factors","en","conference paper","Elsevier","","","","","","","","","Control & Operations","Control & Simulation","","",""
"uuid:9d3b50c1-f09a-41c1-b241-5ef75d7ba5e6","http://resolver.tudelft.nl/uuid:9d3b50c1-f09a-41c1-b241-5ef75d7ba5e6","Dispersion analysis of finite-element schemes for a first-order formulation of the wave equation","Shamasundar, R.; Al-Khoury, R.I.N.; Mulder, W.A.","","2015","We investigated one-dimensional numerical dispersion curves and error behaviour of four finite-element schemes with polynomial basis functions: the standard elements with equidistant nodes, the Legendre-Gauss-Lobatto points, the Chebyshev-Gauss-Lobatto nodes without a weighting function and with. Mass lumping, required for efficiency reasons and enabling explicit time stepping, may adversely affect the numerical error. We show that in some cases, the accuracy can be improved by applying one iteration on the full mass matrix, preconditioned by its lumped version. For polynomials of degree one, this improves the accuracy from second to fourth order in the element size. In other cases, the improvement in accuracy is less dramatic.","","en","conference paper","EAGE","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:e2613d94-6831-4ea0-b148-a395e1551118","http://resolver.tudelft.nl/uuid:e2613d94-6831-4ea0-b148-a395e1551118","Continuous rating of perceived visual-inertial motion incoherence during driving simulation","Cleij, D.; Venrooij, J.; Pretto, P.; Pool, D.M.; Mulder, M.; Bülthoff, H.H.","","2015","Motion cueing algorithms (MCA) are used in motion simulation to map the inertial vehicle motions onto the simulator motion space. To increase fidelity of the motion simulation, these MCAs are tuned to minimize the perceived incoherence between the visual and inertial motion cues. Despite time-invariant MCA dynamics the incoherence is not constant, but changes over time. Currently used methods to measure the quality of an MCA focus on the overall differences between MCAs, but lack the ability to detect how quality varies over time and how this influences the overall quality judgement. This paper describes a continuous subjective rating method with which perceived motion incoherence can be detected over time. An experiment was performed to show the suitability of this method for measuring motion incoherence. The experiment results were used to validate the continuous rating method and showed it provides important additional information on the perceived motion incoherence during a simulation compared to an offline rating method.","driving; simulation; motion; cueing; evaluation","en","conference paper","Max Planck Institute for Biological Cybernetics","","","","","","","","Aerospace Engineering","Control and Simulation","","","",""
"uuid:513b9f39-6129-4a26-820c-883f162d0d22","http://resolver.tudelft.nl/uuid:513b9f39-6129-4a26-820c-883f162d0d22","Use of simulator motion feedback for different classes of vehicle dynamics in manual control tasks","Lu, T.; Pool, D.M.; Van Paassen, M.M.; Mulder, M.","","2015","With the development of moving-based flight simulators in mind, a large number of researchers have considered human manual control behavior in tasks where the motion of the controlled vehicle can be felt by the pilots. While it is known that the dynamics of the controlled vehicle are a key factor that determines the usefulness of motion feedback, there is no systematic study of the use of motion feedback over a wide range of controlled dynamics. Therefore, this paper describes a human-in-the-loop yaw attitude compensatory tracking experiment that was conducted to evaluate the effects of motion feedback on task performance, as well as the open-loop crossover frequency and phase margin. A gain, a single integrator and a double integrator were selected as the different controlled elements in this experiment, respectively. For the double integrator controlled element, the results confirms the findings of previous studies that the motion feedback is crucial in improving task performance and increasing the open-loop phase margin for enhanced stability. However, for both the gain and single integrator controlled elements, the motion feedback is not helpful in the aspect of changing task performance, target crossover frequency and phase margin.","","en","conference paper","Delft University of Technology","","","","","","","","Aerospace Engineering","Control and Simulation","","","",""
"uuid:f243c511-d21f-456c-bc05-20caeb7ebe17","http://resolver.tudelft.nl/uuid:f243c511-d21f-456c-bc05-20caeb7ebe17","Solution space diagram in conflict detection scenarios","Rahman, S.M.A.; Borst, C.; Mulder, M.; Van Paassen, M.M.","","2015","This research investigates the use of Solution Space Diagram (SSD) as a measure of sector complexity and also as a predictor of performance and workload, focusing on the scenarios regarding Air Traffic Controller (ATCO)’s ability to detect future conflicts. A human-in-the-loop experiment with varying intercept angle within the same sector layout has been designed and conducted. A short duration and a single predetermined conflict for each scenario were programmed to ensure a controlled experiment environment. The main aim of this experiment is to investigate whether the SSD can predict the workload ratings and subject performance in a conflict detection task. Based on the results, no common pattern can be observed, which can directly associate workload ratings and SSD area properties for various intercept angles. As conflict presented in the experiment between the converging aircraft, it was found that smaller SSD observation angles correlate better with the workload rating. These results were anticipated, as in converging conditions aircraft ahead of the velocity vector will be captured as the main focus. The SSD also does not represent a trigger for conflict detection. There is no consistent SSD area percentage where ATCO would start detecting conflict. Thus, it is concluded that the SSD does not represent a trigger for conflict detection.","air traffic control; sector complexity; solution space diagram","en","journal article","Penerbit Universiti Teknologi Malaysia Press","","","","","","","","","","","","",""
"uuid:e5221293-3aa4-4b5f-9ba7-00f6ae7e4251","http://resolver.tudelft.nl/uuid:e5221293-3aa4-4b5f-9ba7-00f6ae7e4251","Estimating a continuous p-wave velocity profile with constant squared-slowness gradient models from seismic field data","Ponomarenko, A.V.; Kashtan, B.M.; Troyan, V.N.; Mulder, W.A.","","2015","We inverted seismic field data for a continuous, laterally invariant P-wave velocity profile. Instead of the usual approach that involves horizontal layers with piecewise constant densities and velocities, we consider models of one or two layers with a constant gradient of the squared slowness above a homogeneous halfspace. With a single layer above a halfspace, there are three parameters. With two layers, there are five. We solve the inverse problem by a direct grid search over a wide range of parameters. The results were compared to that of a piecewise-constant multi-layer inversion result. In the single-layer case, either the shallow or the deeper part of the model would match the multi-layer case, depending on which modes of the surface waves were selected. With two layers, a considerably better agreement is obtained over a larger depth range. Our method is limited to cases with a small Vs/Vp-ratio but has only 5 parameters. It could be a useful alternative to piecewise-constant multi-layer inversion, in particular if continuous P-velocity profiles are sought. These are sometimes better suited as a starting model for full waveform inversion than models with many discontinuities.","","en","conference paper","EAGE","","","","","","","","Civil Engineering and Geosciences","Geoscience and Engineering","","","",""
"uuid:f2de0964-7bf9-4232-aae0-3b3fff3f953e","http://resolver.tudelft.nl/uuid:f2de0964-7bf9-4232-aae0-3b3fff3f953e","Rigid-body kinematics versus flapping kinematics of a flapping wing micro air vehicle","Caetano, J.V.; Weehuizen, M.B.; De Visser, C.C.; De Croon, G.C.H.E.; Mulder, M.","","2015","Several formulations have been proposed to model the dynamics of ornithopters, with inconclusive results regarding the need for complex kinematic formulations. Furthermore, the impact of assumptions made in the collected results was never assessed by comparing simulations with real flight data. In this study two dynamic models of a Flapping Wing Micro Aerial Vehicle (FWMAV) were derived and compared: a) single rigid body aircraft equations of motion and b) Virtual Work Principle derivation for multiple rigid body flapping kinematics. The aerodynamic forces and moments were compared by feeding the states that were reconstructed from the position and attitude data of a 17 gram free flying FWMAV into the dynamic equations of both formulations. To understand the applicability of rigid body formulations to FWMAVs, six wing-to-body mass ratios and two wing configurations were studied using real flight data. The results show that rigid body models are valid for the aerodynamic reconstruction of FWMAVs with four wings in ‘X’ configuration and two-winged FWMAV with a total wing-to-body mass ratio below 24% and 5.6%, respectively, without considerable information loss.","","en","journal article","AIAA","","","","","","","","Aerospace Engineering","","","","",""
"uuid:4cc4050e-55dd-4687-9873-3b3ad727ebb0","http://resolver.tudelft.nl/uuid:4cc4050e-55dd-4687-9873-3b3ad727ebb0","Predicting the ungauged basin: Model validation and realism assessment","Van Emmerik, T.H.M.; Mulder, G.; Eilander, D.; Piet, M.; Savenije, H.H.G.","","2015","The hydrological decade on Predictions in Ungauged Basins (PUB) led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of model outcome has not been discussed to a great extent. With this paper we aim to contribute to the discussion on how one can determine the value and validity of a hydrological model developed for an ungauged basin. As in many cases no local, or even regional, data are available, alternative methods should be applied. Using a PUB case study in a genuinely ungauged basin in southern Cambodia, we give several examples of how one can use different types of soft data to improve model design, calibrate and validate the model, and assess the realism of the model output. A rainfall-runoff model was coupled to an irrigation reservoir, allowing the use of additional and unconventional data. The model was mainly forced with remote sensing data, and local knowledge was used to constrain the parameters. Model realism assessment was done using data from surveys. This resulted in a successful reconstruction of the reservoir dynamics, and revealed the different hydrological characteristics of the two topographical classes. This paper does not present a generic approach that can be transferred to other ungauged catchments, but it aims to show how clever model design and alternative data acquisition can result in a valuable hydrological model for an ungauged catchment.","PUB; hydrologic modeling; Cambodia; ungauged basins; remote sensing; model realism; model validation; soft data","en","journal article","Frontiers","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:a01a711a-5fff-4d19-8986-03b9fed372a4","http://resolver.tudelft.nl/uuid:a01a711a-5fff-4d19-8986-03b9fed372a4","Next generation sequencing of triple negative breast cancer to find predictors for chemotherapy response","Lips, Esther H. (Netherlands Cancer Institute); Michaut, Magali (Netherlands Cancer Institute); Hoogstraat, Marlous (Netherlands Cancer Institute; University Medical Center Utrecht); Mulder, Lennart (Netherlands Cancer Institute); Besselink, Nicole J.M. (University Medical Center Utrecht); Koudijs, Marco J. (University Medical Center Utrecht); Cuppen, Edwin (University Medical Center Utrecht); Voest, Emile E. (University Medical Center Utrecht; Netherlands Cancer Institute); Bernards, Rene (Netherlands Cancer Institute); Nederlof, Petra M. (Netherlands Cancer Institute); Wesseling, Jelle (Netherlands Cancer Institute); Rodenhuis, Sjoerd (Netherlands Cancer Institute); Wessels, L.F.A. (TU Delft Pattern Recognition and Bioinformatics)","","2015","Introduction
In triple negative breast cancers (TNBC) the initial response to chemotherapy is often favorable, but relapse and chemotherapy resistance frequently occur in advanced disease. Hence there is an urgent need for targeted treatments in this breast cancer subtype. In the current study we deep sequenced DNA of tumors prior to chemotherapy to search for predictors of response or resistance.
Methods
Next generation sequencing (NGS) was performed for 1,977 genes involved in tumorigenesis. DNA from 56 pre-treatment TNBC-biopsies was sequenced, as well as matched normal DNA. Following their tumor biopsy, patients started neoadjuvant chemotherapy with doxorubicin and cyclophosphamide. We studied associations between genetic alterations and three clinical variables: chemotherapy response, relapse-free survival and BRCA proficiency.
Results
The mutations observed were diverse and few recurrent mutations were detected. Most mutations were in TP53, TTN, and PIK3CA (55 %, 14 %, and 9 %, respectively). The mutation rates were similar between responders and non-responders (average mutation rate 9 vs 8 mutations). No recurrent mutations were associated with chemotherapy response or relapse. Interestingly, PIK3CA mutations were exclusively observed in patients proficient for BRCA1. Samples with a relapse had a higher copy number alteration rate, and amplifications of TTK and TP53BP2 were associated with a poor chemotherapy response.
Conclusions
In this homogenous cohort of TNBCs few recurrent mutations were found. However, PIK3CA mutations were associated with BRCA proficiency, which can have clinical consequences in the near future.
framework and a transdisciplinary design approach to innovate HCI education.
Students do not work for a client, but work together with urban stakeholders to
better frame the problem in order to deal with societal challenges. In this way,
Applab embraces design thinking as an approach to leverage a crossdisciplinary
collaboration between research, government, industry, and HCI and
design education. Results are described as well as lessons learnt. Consequently,
the elaborate Applab model is discussed. Interestingly, the corresponding
transdisciplinary design approach enabled a successful implementation of
Applab into HCI education. Students learnt a lot, as did the urban stakeholders.
The designed artefacts greatly leveraged their mind-shifting and meaningful
learning experiences.
20 degrees necessary), while pitch is of less importance (<5 degrees necessary) and heave (less than 10 cm) can almost be neglected. These findings are of importance for developing boat simulators and other virtual sports applications that employ actuated platforms","sailing, dinghy, presence questionnaire, virtual reality, training simulation, motion platform","en","conference paper","International Society for Presence Research","","","","","","","","Industrial Design Engineering","Design Engineering","","","",""
"uuid:e80cabbf-bbf1-488c-b910-f60da93ebc8a","http://resolver.tudelft.nl/uuid:e80cabbf-bbf1-488c-b910-f60da93ebc8a","From gut feeling to a structured summative assessment of design competencies","Schelling, J.; Leurs, B.; Best, S.; Mulder, I.J.","","2012","","","en","conference paper","The Design Society, Institution of Engineering Designers","","","","","","","","Industrial Design Engineering","Industrial Design","","","",""
"uuid:4d340c05-e15c-403d-9648-ef5c8af7de06","http://resolver.tudelft.nl/uuid:4d340c05-e15c-403d-9648-ef5c8af7de06","Co-creatie in het publieke domein: Een vanzelfsprekendheid","Mulder, I.J.","","2012","","","nl","book chapter","Stichting Toekomstbeeld der Techniek","","","","","","","","Industrial Design Engineering","Industrial Design","","","",""
"uuid:0385de65-9ee2-4918-8a85-39a0e2886ad5","http://resolver.tudelft.nl/uuid:0385de65-9ee2-4918-8a85-39a0e2886ad5","A Place to be Proud of: Heritage and Social inclusion in Shrinking Cities (Germany and United Kingdom)","Mulder, A.","","2012","Many old industrial areas of Europe and beyond have seen population numbers fall. When the numbers of households also starts to drop, demand for housing decreases. This may result in high numbers of empty dwellings, especially when either the houses themselves or the areas in which they stand are unattractive. In countries like Germany and the United Kingdom, governments (both local and national) have recognised this as a problem and developed strategies to deal with it.","","en","book chapter","OECD/LEED","","","","","","","","Architecture","Real Estate and Housing","","","",""
"uuid:5d0d8740-597b-413f-bb9c-2353a34458a2","http://resolver.tudelft.nl/uuid:5d0d8740-597b-413f-bb9c-2353a34458a2","Subsurface offset behaviour in velocity analysis with extended reflectivity images","Mulder, W.A.","","2012","Migration velocity analysis with the wave equation can be accomplished by focusing of extended migration images, obtained by introducing a subsurface offset or shift. A reflector in the wrong velocity model will show up as a curve in the extended image. In the correct model, it should collapse to a point. The usual approach to obtain a focused image involves a cost functional that penalizes energy in the extended image at non-zero shift. Its minimization by a gradient-based method should then produce the correct velocity model. Here, asymptotic analysis and numerical examples show that this method may be too sensitive to amplitude peaks at large shifts at the wrong depth and to artifacts. A more robust alternative is proposed that can be interpreted as a generalization of stack power and maximizes the energy at zero subsurface shift. A real-data example is included.","","en","conference paper","EAGE","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:775d343f-664c-4d4e-888e-f6200bb319c1","http://resolver.tudelft.nl/uuid:775d343f-664c-4d4e-888e-f6200bb319c1","The diagonalator: An alternative cost functional for wave-equation inversion","Poor Moghaddam, P.; Mulder, W.A.","","2012","The classic least-squares cost functional for full waveform inversion suffers from local minima due to loop skipping in the absence of low frequencies in the seismic data. Velocity model building based on subsurface spatial or temporal shifts may break down in the presence of multiples in the data. Cost functionals that translate this idea to the data domain, with offset- or time-shifts, can handle multiples. An earlier data-domain formulation suffered from cross-talk between events. Here, we present a multishot extension that should be less sensitive to cross-talk. It has the property of an annihilator, similar to the functional used for velocity analysis with extended images based on subsurface shifs. However, since it operates in the data domain, it should be able to handle multiples. For 2-D models with line acquistion, the proposed functional applies a singular-value decomposition on the observed data and uses the eigenvectors to build data panel that should be diagonal in the correct velocity model, but has significant off-diagonal entries in the wrong model. By minimizing these offdiagonal entries or maximizing the main diagonal, the correct model should be found. We therefore named it the diagonalator. We present initial tests on a simple, horizontally layered velocity model.","","en","conference paper","EAGE","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:511a9ba6-ef6c-43f7-ad3f-f81d06f8a4ac","http://resolver.tudelft.nl/uuid:511a9ba6-ef6c-43f7-ad3f-f81d06f8a4ac","Chaordisch onderwijs en onderzoek","Mulder, I.J.; Van den Hilligersberg, J.; Van Till, J.W.J.","","2012","Hoger-onderwijsinstellingen voelen de druk van veranderende wensen van de omgeving. De overheid stuurt met harde prestatieafspraken: hoger studierendement en lagere uitval. Ook het wisselen van opleiding en het volgen van een tweede studie moeten zoveel mogelijk worden uitgebannen. Tegelijkertijd wenst het bedrijfsleven méér dan inhoudelijk geschoolde studenten. Bedrijven en andere organisaties werken al lang niet meer vooral industrieel-hiërarchisch, en vragen geen uitwisselbare ‘fabrieksarbeiders’. Creativiteit, zelfsturing en communicatieve vaardigheid worden alom genoemd als basis voor een moderne carrière. Vooral het vermogen om samen te werken in nieuwe onverwachte combinaties is gewild. Wie over schuttingen heen kijkt bij het onderzoeken van problemen, het bedenken van oplossingen, en het leren van en met anderen, is meer dan welkom. Helaas dreigt het hoger onderwijs – als reactie op de toenemende druk – terug te vallen op het traditionele kwaliteitsen efficiencydenken. Er is een golf van top-down-initiatieven gericht op minder kosten, meer controle, meer regels, aanpakken van langstudeerders, accreditatieprocessen, efficiëntie in het curriculum, registratie van contacturen, nieuwe bekostigingsmodellen, schaalvergroting enzovoort. Deze dominante denktrant draagt het risico in zich, dat het hoger onderwijs verwordt tot een les- en onderzoeksfabriek waar alleen efficiëntie en aantallen tellen.","","nl","book chapter","SURF","","","","","","","","Industrial Design Engineering","Industrial Design","","","",""
"uuid:28941c43-15e6-4683-a642-1225bbf2b310","http://resolver.tudelft.nl/uuid:28941c43-15e6-4683-a642-1225bbf2b310","Learning to build on history: The regeneration of low income housing estates in England and Germany","Mulder, A.","","2012","When dwellings become obsolete or even vacant, the usual response by landlords or politicians would be: tear them down. However by doing so, part of the local history, which is also the history of the people still living there, will be destroyed. In Germany during the 1970s and 1980s, people in the Ruhr area, which was facing the closure of coal mines and steel plants for several decades, started thinking out of the box. Instead of demolishing them, plans were developed to find a new use for the old factory buildings and to retain the adjacent housing estates. Some ten years iater, the same trend could be observed in England. Both countries have since developed tools to fight the negative consequences of popuiation decline in old industrial areas. These tools include: the German ""building exhibitions"" (IBAs) and the English ""housing market renewal pathfinders"" (HMRPs). This paper will focus on these tools and especially on projects that aim to reuse existing dwellings to help revive an area. Chimney Pot Park within the Manchester Salford Housing Market Renewal Pathfinder area and Schüngeiberg Garden City, part of the IBA Emscher Park, will be taken as examples. Before moving on to these projects each section will start with a general description ofthe area, followed by a short discussion of the main goals of the policy tool involved.","","en","journal article","","","","","","","","","Architecture","Real Estate and Housing","","","",""
"uuid:322af637-17d2-430b-bb1e-839031081bc0","http://resolver.tudelft.nl/uuid:322af637-17d2-430b-bb1e-839031081bc0","Scenario based learning regarding contested articulations of sustainability: The example of hydropower and Sweden's energy future","Mulder, K.F.; Petrik, O.; Parandian, A.; Grondahl, F.","","2012","Providing electricity from renewable sources is of key importance both to reduce depletion of fossil fuels and reduce emissions of greenhouse gasses. Many of the renewable energy technologies are not ideal for electricity networks. Reservoir hydropower is one of the most ideal renewable sources as it can store energy efficiently, and can be made quickly available in cases of peak loads. Reservoir hydropower generation has considerable impact on the landscape. Reservoirs and dams are perhaps the most visible elements, but the effects of a regulated flow of rivers on the river ecosystem, and the ecology of the river banks, is considerable. In Sweden, hydropower has a long tradition of being an arena for environmental controversy. Historically, various river related economic interests collided, but nowadays river basin ecology and sports fisheries are important issues too. [cf. 1]. Swedish Government has high ambitions regarding climate change: it aims at becoming the first fossil free country within 40 years. Unlike the traditional image of Swedish society, there is no consensus on the hydropower issue but a fortified dissensus. Communication between the contestants is limited to regular clashes (accusations) in the media rather than sensible interaction between different stakeholders on basis of substance of the issues at stake. This paper describes a specific approach which brings together different stakeholders in an orchestrated and supported setting so that interaction between different stakeholders can take place on basis of the content and substance of various issues that are faced. The main aim of the workshop was to facilitate interaction through which the participants could gain a more substantive insight in each other’s positions and background arguments regarding different issues at hand. The interaction was supported by specific tools: External scenarios and value based scenarios were developed for analyzing the future of (hydro-) electricity production in Sweden. We evaluate specific learning effect of the participants as a measure of productivity of our approach. The attendance of the workshop was very good. Our post workshop evaluations show very encouraging results in terms of new insights in each other’s positions.","learning; scenario workshops; hydropower; climate change; biodiversity","en","journal article","IASKS","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:8dee6494-4452-47f2-b5e9-f7c1b72a054b","http://resolver.tudelft.nl/uuid:8dee6494-4452-47f2-b5e9-f7c1b72a054b","Living labbing the Rotterdam way: Co-creation as an enabler for urban innovation","Mulder, I.J.","","2012","The living lab concept seems appropriate to study the design and evaluation of innovative services that enrich everyday life. This article elaborates on “living methodologies”, methods and tools necessary in ""living labbing"". Living methodologies address the social dynamics of everyday life that are essential for understanding living labs, not only conceptually, but also as mature methodologies for fostering innovation in real-life contexts. We report on three cases from Rotterdam in the Netherlands, where ""living labbing"" was used to enable citizens to co-develop their city. These cases utilized visual ethnography as a research method and prototyping and co-creating as design tools. The cases not only inspire citizen participation, but also inform social innovation and city’s policymaking. The user-driven approach, do-it-yourself mindset, and the participatory character perfectly fit with the down-to-earth attitude of Rotterdam residents","","en","journal article","Carleton University","","","","","","","","Industrial Design Engineering","Industrial Design","","","",""
"uuid:b6601e30-ddc9-4aea-b66e-6e7abdeec9b5","http://resolver.tudelft.nl/uuid:b6601e30-ddc9-4aea-b66e-6e7abdeec9b5","Thermal Stability of MgyTi1-y Thin Films Investigated by Positron Annihilation Spectroscopy","Anastasopol, A.; Eijt, S.W.H.; Schut, H.; Mulder, F.M.; Plazaola, F.; Dam, B.","","2012","Mg-Ti compounds are attractive candidates as hydrogen storage materials for their fast sorption kinetics and high storage capacity. In this context, an investigation of their thermal stability is of great importance. The thermal stability of MgyTi1-y thin films was investigated using positron annihilation spectroscopy. Despite the positive enthalpy of mixing of Mg and Ti, positron Doppler Broadening of Annihilation Radiation (DBAR) depth profiling showed that Mg0.9Ti0.1 films are stable up to 300°C. However, for Mg0.7Ti0.3 films, segregation of Mg and Ti was observed at 300oC by the appearance of a clear Ti signature in the S-W diagrams and in the Doppler broadening depth profiles analyzed using VEPFIT. The thickness of the 250-300 nm thin films remained unchanged during the heating treatments. We further present ab-initio calculations of positron lifetimes of the corresponding metal and metal hydride phases for comparison to our previous positron annihilation lifetime spectroscopy (PALS) study.","Mg-Ti alloys; thin films; Doppler broadening depth profiling; positron annihilation lifetime spectroscopy; ab-initio calculations","en","journal article","Elsevier","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:e070de9d-e805-4aa5-9bcc-7f8719bb56e1","http://resolver.tudelft.nl/uuid:e070de9d-e805-4aa5-9bcc-7f8719bb56e1","A novel adaptive kernel method with kernel centers determined by a support vector regression approach","Sun, L.G.; De Visser, C.C.; Chu, Q.P.; Mulder, J.A.","","2012","The optimality of the kernel number and kernel centers plays a significant role in determining the approximation power of nearly all kernel methods. However, the process of choosing optimal kernels is always formulated as a global optimization task, which is hard to accomplish. Recently, an algorithm, namely improved recursive reduced least squares support vector regression (IRR-LSSVR), was proposed for establishing a global nonparametric offline model, which demonstrates significant advantage in choosing representing and fewer support vectors compared with others. Inspired by the IRR- LSSVR, a new adaptive parametric kernel method called WV-LSSVR is proposed in this paper using the same type of kernels and the same centers as those used in the IRR-LSSVR. Furthermore, inspired by the multikernel semiparametric support vector regression, the effect of the kernel extension is investigated in a recursive regression framework, and a recursive kernel method called GPK-LSSVR is proposed using a compound type of kernels which are recommended for Gaussian process regression. Numerical experiments on benchmark data sets confirm the validity and effectiveness of the presented algorithms. The WV-LSSVR algorithm shows higher approximation accuracy than the recursive parametric kernel method using the centers calculated by the k-means clustering approach. The extended recursive kernel method (i.e. GPK-LSSVR) has not shown advantage in terms of global approximation accuracy when validating the test data set without real-time updation, but it can increase modeling accuracy if the real-time identification is involved.","support vector machine; recursive identification; adaptive model; kernel basis function","en","journal article","Elsevier","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:9fd478ea-59b6-4c2a-a448-66ed61c18c89","http://resolver.tudelft.nl/uuid:9fd478ea-59b6-4c2a-a448-66ed61c18c89","Design after decline: How America rebuilds shrinking cities. Brent D. Ryan","Mulder, A.","","2012","","shrinking cities; architecture; planning","en","book","Springer","","","","","","Campus only","2013-10-26","Architecture and The Built Environment","Real Estate & Housing","","","",""
"uuid:2026be99-3fdc-4afb-b41a-171380ff270b","http://resolver.tudelft.nl/uuid:2026be99-3fdc-4afb-b41a-171380ff270b","Tailored electrode morphologies for insertion electrodes (abstract)","Wagemaker, M.; Singh, D.P.; George, A.; Ten Elshof, J.E.; Mulder, F.M.","","2012","","","en","conference paper","The Electrochemical Society","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:02c8225b-1ab9-464d-ac3a-1628999f2250","http://resolver.tudelft.nl/uuid:02c8225b-1ab9-464d-ac3a-1628999f2250","Arrival Trajectory Optimization for Passenger Aircraft using Genetic Algorithms","Yu, H.; Mulder, J.A.","","2012","This work concentrates on the development of an optimization technique which is capable of minimizing the noise impact of an arriving aircraft by optimizing its flight trajectory. Actions needed from pilots to gradually establish the landing configuration are considered because it is expected that the pilot workload throughout this phase should be remained or even reduced compared with the current standard arrival procedures. Therefore, the conventional point-mass equations of motion are reformulated in such a way that the variations of the aerodynamic performance of the aircraft of different configurations can be easily taken into account. A set of independent state variables are chosen to be parameterized with Bernstein polynomials in order to convert the infinite-dimensional optimal control problem into a finite-dimensional parametric optimization problem. The number of awakenings is selected as the performance index and finally written into a function of the parameters introduced by the parameterization process. Genetic algorithms are employed to optimize these parameters within a search domain in order to minimize the number of awakenings while satisfying all constraints on both state and control variables. A number of numerical examples, for a Boeing 747-400 aircraft arriving at an airport with different population distribution situations, are provided to demonstrate the feasibility and effectiveness of the proposed optimization technique. Without loss of generality, this particular technique is also able to deal with a departing aircraft since most of the models are built into replaceable modules.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:10f803df-5f7c-44c5-9925-e386f31f0c69","http://resolver.tudelft.nl/uuid:10f803df-5f7c-44c5-9925-e386f31f0c69","Inversion of seismic reflection data through focusing","Mulder, W.A.","","2012","Since most of the easy hydrocarbon reservoirs have been found, accurate sub-surface imaging for oil and gas exploration and production is crucial. Seismic data can provide a band-limited reconstruction of impedance contrasts between different rock formations as well as a subsurface velocity model. Current compute power allows for the use of the full acoustic wave equation for seismic imaging and processing. Least-squares data fitting is an obvious approach but may provide the wrong answer because of local minima in the cost function caused by the absence of low frequencies in the data. An alternative formulation is based on extended images that invokes action at distance to make up for errors in the estimated subsurface velocity model. The action at distance is accomplished by a subsurface shift and the correct model should focus amplitudes at zero shift. The related cost function penalizes image amplitudes at non-zero shift. It has a large basin of attraction but loses its sharpness closer to the minimum. A new formulation is proposed – motivated by high-frequency asymptotic analysis – that provides better results on synthetic and real seismic data and is less sensitive to imaging artifacts.","seismic inversion; acoustics; imaging; subsurface characterization","en","conference paper","Vienna University of Technology","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:73f7f82f-a675-469a-8821-28f93ed5e321","http://resolver.tudelft.nl/uuid:73f7f82f-a675-469a-8821-28f93ed5e321","Measuring Sector Complexity: Solution Space-Based Method","Abdul Rahman, S.M.B.; Borst, C.; Mulder, M.; Van Paassen, M.M.","","2012","","","en","book chapter","InTech","","","","","","","","Aerospace Engineering","Control and Operations","","","",""
"uuid:c342f02e-180d-434c-ac0f-988a8d01e856","http://resolver.tudelft.nl/uuid:c342f02e-180d-434c-ac0f-988a8d01e856","Quasi-analytical method for frequency-to-time conversion in CSEM applications","Moradi Tehrani, A.; Slob, E.C.; Mulder, W.","","2012","Frequency-to-time transformations are of interest to controlled-source electromagnetic methods when time-domain data are inverted for a subsurface resistivity model by numerical frequency-domain modeling at a selected, small number of frequencies whereas the data misfit is determined in the time domain. We propose an efficient, Prony-type method using frequency-domain diffusive-field basis functions for which the time-domain equivalents are known. Diffusive fields are characterized by an exponential part whose argument is proportional to the square root of frequency and a part that is polynomial in integer powers of the square root of frequency. Data at a limited number of frequencies suffice for the transformation back to the time. In the exponential part, several diffusion-time values must be chosen. Once a suitable range of diffusion-time values are found, the method is quite robust in the number of values used. The highest power in the polynomial part can be determined from the source and receiver type. When the frequency-domain data are accurately approximated by the basis functions, the timedomain result is also accurate. This method is accurate over a wider time range than other methods and has the correct late-time asymptotic behavior. The method works well for data computed for layered and 3D subsurface models.","","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geoscience & Technology","","","",""
"uuid:c67863ad-3e92-4bde-a737-0bb97263a646","http://resolver.tudelft.nl/uuid:c67863ad-3e92-4bde-a737-0bb97263a646","3D Spatial Data Infrastructure","Goos, J.; Boersma, A.J.; Mulder, A.; Zlatanova, S.","","2012","","","en","conference paper","","","","","","","","","OTB Research Institute for the Built Environment","OTB Research","","","",""
"uuid:352f7443-7989-4ce7-8cfc-c235616aa72f","http://resolver.tudelft.nl/uuid:352f7443-7989-4ce7-8cfc-c235616aa72f","A comparison of explicit continuous and discontinuous Galerkin methods and finite differences for wave propagation in 3D heterogeneous media","Minisini, S.; Mulder, W.A.; Zhebel, E.; Kononov, A.","","2012","Abstract only.","high-order continuous; discontinuous finite elements; mass-lumping; heterogeneous media","en","conference paper","Vienna University of Technology","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:8f7143b0-2e63-474d-8eb7-a58dd180cb66","http://resolver.tudelft.nl/uuid:8f7143b0-2e63-474d-8eb7-a58dd180cb66","Incorporating EM Inversion into Reservoir Monitoring","Wirianto, M.; Mulder, W.A.; Slob, E.C.","","2012","In the application of controlled source electromagnetics for reservoir monitoring on land, the timelapse signal measured with a surface-to-surface acquisition can reveal the lateral extent on the surface of resistivity changes at depth in a hydrocarbon reservoir under production. However, a direct interpretation of the time-lapse signal may generally be difficult and biased. We investigated if non-linear inversion can use time-lapse responses to characterize the subsurface resistivity changes. We examined two different strategies, using a full non-linear inversion algorithm as the interpretation tool: inverting the reference and monitor data independently or in sequence. In the second case, the inversion result of the reference data set serves as an initial guess for the inversion of the monitor data set. Numerical examples show that independent inversion of the data sets can provide an estimate of the depth and lateral extent of the resistivity changes. The second strategy of sequential inversion produces less satisfactory results. We illustrate the independent inversion approach for an example with large survey repeatability errors are large and another one with a complex overburden.","","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:0f0b7743-c611-4754-ac69-505651b052d8","http://resolver.tudelft.nl/uuid:0f0b7743-c611-4754-ac69-505651b052d8","On the Contribution of Head Waves to Full Waveform Inversion","Kazei, V.V.; Ponomarenko, A.V.; Troyan, V.N.; Kashtan, B.M.; Mulder, W.A.","","2012","Full waveform inversion suffers from local minima, due to a lack of low frequencies in the data. A reflector below the zone of interest may, however, help in recovering the long-wavelength components of a velocity perturbation, as demonstrated in a paper by Mora. With the Born approximation for the perturbation in a reference model consisting of two homogeneous isotropic acoustic halfspaces, analytic expressions can be found that describe the spatial spectrum of the recorded seismic signal as a function of the spatial spectrum of the inhomogeneity. We study this spectrum in more detail by separately considering direct, reflected and head waves. Taking the reflection coefficient of the deeper reflector into account, we obtain sensitivity estimates for each of these types of waves. Although the head waves have a relatively small contribution to the reconstruction of the velocity perturbation, compared to the other waves, they contain reliable long-wavelength information that can be beneficial for full waveform inversion.","","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:7d70ca9b-d102-4f00-a75c-3cdb55f17df5","http://resolver.tudelft.nl/uuid:7d70ca9b-d102-4f00-a75c-3cdb55f17df5","On the time-stepping stability of continuous mass-lumped and discontinuous Galerkin finite elements for the 3D acoustic wave equation","Zhebel, E.; Minisini, S.; Mulder, W.A.","","2012","We solve the three-dimensional acoustic wave equation, discretized on tetrahedral meshes. Two methods are considered: mass-lumped continuous finite elements and the symmetric interior-penalty discontinuous Galerkin method (SIP-DG). Combining the spatial discretization with the leap-frog time-stepping scheme, which is second-order accurate and conditionally stable, leads to a fully explicit scheme. We provide estimates of its stability limit for simple cases, namely, the reference element with Neumann boundary conditions, its distorted version of arbitrary shape, the unit cube that can be partitioned into 6 tetrahedra with periodic boundary conditions, and its distortions. The CFL stability limit contains a length scale for which we considered different options. The one based on the sum of the eigenvalues of the spatial operator for the first degree mass-lumped element gives the best results. It resembles the diameter of the inscribed sphere but is slightly easier to compute. The stability estimates show that mass-lumped continuous and SIP-DG finite elements have comparable stability conditions, with the exception of the elements of the first degree. The stability limit for the mass-lumped elements is less restrictive and allows for larger time steps.","stability; mass lumping; finite elements; discontinuous Galerkin; acoustic wave; equation","en","conference paper","Vienna University of Technology","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:c45304e8-b3df-4a0e-a95a-d998235a51a1","http://resolver.tudelft.nl/uuid:c45304e8-b3df-4a0e-a95a-d998235a51a1","A Comparison of Continuous Mass-lumped Finite Elements and Finite Differences for 3D","Zhebel, E.; Minisini, S.; Kononov, A.; Mulder, W.A.","","2012","The finite-difference method is widely used for time-domain modelling of the wave equation because of its ease of implementation of high-order spatial discretization schemes, parallelization and computational efficiency. However, finite elements on tetrahedral meshes are more accurate in complex geometries near sharp interfaces. We compared the fourth-order finite-difference method to fourth-order continuous masslumped finite elements in terms of accuracy and computational cost. The results show that for simple models like a cube with constant density and velocity, the finite-difference method outperforms the finite-element method by at least an order of magnitude. For a model with interior complexity and topography, however, the finite elements are about two orders of magnitude faster than finite differences.","","en","conference paper","EAGE","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:a5077cbf-4fe2-4560-a424-4bbf47f732a8","http://resolver.tudelft.nl/uuid:a5077cbf-4fe2-4560-a424-4bbf47f732a8","A 3D Tetrahedral Mesh Generator for Seismic Problems","Kononov, A.; Minisini, S.; Zhebel, E.; Mulder, W.A.","","2012","Finite-element modelling of seismic wave propagation on tetrahedra requires meshes that accurately follow interfaces between impedance contrasts or surface topography and have element sizes proportional to the local velocity. We explain a mesh generation approach by example. Starting from a finite-difference representation of the velocity model, triangulated surfaces are generated along impedance discontinuities. These define subdomains that are meshed independently and in parallel, honouring the local velocity values. The resulting volumetric meshes are merged into a single mesh. The approach is flexible, efficient, scalable and capable of producing quality meshes.","","en","conference paper","EAGE","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:a2c15842-bd69-49e0-992b-18060dc49f2e","http://resolver.tudelft.nl/uuid:a2c15842-bd69-49e0-992b-18060dc49f2e","Efficiency Comparison for Continuous Mass-lumped and Discontinuous Galerkin Finite-elements for 3D Wave Propagation","Minisini, S.; Zhebel, E.; Kononov, A.; Mulder, W.A.","","2012","The spreading adoption of computationally intensive techniques such as Reverse Time Migration and Full Waveform Inversion increases the need of efficiently solving the three-dimensional wave equation. Common finite-difference discretization schemes lose their accuracy and efficiency in complex geological settings with discontinuities in the material properties and topography. Finite elements on tetrahedral meshes follow the interfaces while maintaining their accuracy and can have smaller meshes if the elements are scaled with the velocity. Here, we consider two higher-order finite element methods that allow for explicit time stepping: the continuous mass-lumped finite-element method (CMLFE) and the symmetric interior penalty discontinuous Galerkin method (SIPDG). The price paid for the ability to perform explicit time stepping is an increase in computational cost: CMLFE requires a larger number of discretization nodes to preserve accuracy, whereas SIPDG needs additional fluxes to impose the continuity of the solution. Therefore, it is not obvious which one is more efficient. We compare the two methods in terms of accuracy, stability and computational cost. Experiments on a three-dimensional problem with a dipping interface show that CMLFE and SIPDG have similar stability conditions, accuracy and efficiency, the last being measured as the computational time required to reach a given accuracy of the result.","","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:e9dd45cd-a7ba-456a-b561-8b785a08e2d3","http://resolver.tudelft.nl/uuid:e9dd45cd-a7ba-456a-b561-8b785a08e2d3","Evaluation of micro-structural damage caused by needle penetration testing","Ngan-Tillard, D.J.M.; Engin, H.K.; Verwaal, W.; Mulder, A.; Ulusay, R.; Erguler, Z.A.","","2012","The needle penetrometer (NP) is a nondestructive, cheap and simple device which can be used indirectly to obtain the uniaxial compressive strength of extremely weak rocks. It requires little sample preparation and can be used in the field and laboratory and applied in natural and man-made structures where sampling is not allowed. The microstructural damage created by the needle, its shape and size, have been assessed using four rock types (marl, mudstone and tuff from Turkey and calcarenite from the Netherlands) and two types of needle. During needle penetration, very high compressive and shear stresses are developed in advance of the needle and normal to the shaft. In all the tested rocks, densification occurred in a zone some 0.4 and 1 mm ahead of the Maruto and Eijkelkamp needles respectively. The grains are crushed and compacted in a zone which appears like an extension of the needle tip (Eijkelkamp needle). As damage is local, the NP test is said to be non-destructive. The NP results in coarse grained rocks are far more variable than in fine grained rocks. The damage caused by a needle decreases with a decrease in the diameter of the needle and an increase in the slenderness of the needle.","needle penetrometer; needle penetration resistance; microstructural damage; tuff; calcarenite; mudstone; marl","en","journal article","Springer","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:c1f3a182-aa46-4347-8160-77eb88ee4657","http://resolver.tudelft.nl/uuid:c1f3a182-aa46-4347-8160-77eb88ee4657","A new empirical complex electrical resistivity model","Kavian, M.; Slob, E.C.; Mulder, W.A.","","2012","Macroscopic measurements of electrical resistivity require frequency-dependent effective models that honor the microscopic effects observable in macroscopic measurements. Effective models based on microscopic physics exist alongside with empirical models. We adopted an empirical model approach to modify an existing physical model. This provided a description of electrical resistivity as a function of not only frequency, but also water saturation. We performed two-electrode laboratory measurements of the complex resistivity on a number of fine and medium-grained unconsolidated sand packs saturated with water of three different salinities. For frequencies between 0.1 and 1 MHz, the data were fitted with the new model and compared to fits with Archie’s law. Our model described the relaxation times and DC resistivity values as negative exponential functions with increasing water saturation. All data could be accurately described as a function of frequency and water saturation with nine parameters.","","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:853c9166-a369-4174-b0e0-d8084f6797b8","http://resolver.tudelft.nl/uuid:853c9166-a369-4174-b0e0-d8084f6797b8","Drawing lines in the sand: The evolution of Dutch coastal policy","Slinger, J.H.; Vreugdenhil, H.; Hermans, L.M.; Cunningham, S.; Bruens, A.; Mulder, J.; Menke, M.","","2012","","","en","conference paper","","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:77c42d1d-d9ab-409d-9f7d-abf72433cfc6","http://resolver.tudelft.nl/uuid:77c42d1d-d9ab-409d-9f7d-abf72433cfc6","Haptic shared control: Smoothly shifting control authority?","Abbink, D.A.; Mulder, M.; Boer, E.R.","","2012","Literature points to persistent issues in humanautomation interaction, which are caused either when the human does not understand the automation or when the automation does not understand the human. Design guidelines for human-automation interaction aim to avoid such issues and commonly agree that the human should have continuous interaction and communication with the automation system and its authority level and should retain final authority. This paper argues that haptic shared control is a promising approach to meet the commonly voiced design guidelines for human-automation interaction, especially for automotive applications. The goal of the paper is to provide evidence for this statement, by discussing several realizations of haptic shared control found in literature. We show that literature provides ample experimental evidence that haptic shared control can lead to short-term performance benefits (e.g., faster and more accurate vehicle control; lower levels of control effort; reduced demand for visual attention). We conclude that although the continuous intuitive physical interaction inherent in haptic shared control is expected to reduce long-term issues with humanautomation interaction, little experimental evidence for this is provided. Therefore, future research on haptic shared control should focus more on issues related to long-term use such as trust, overreliance, dependency on the system, and retention of skills","automation; humanmachine interface; haptic guidance; shared control; neuromuscular identification; levels of automation; force feedback","en","journal article","Springer-Verlag","","","","","","","","Mechanical, Maritime and Materials Engineering","Department of Biomechanical Engineering","","","",""
"uuid:ca663053-c19b-4037-9e6b-dca71a0b31ba","http://resolver.tudelft.nl/uuid:ca663053-c19b-4037-9e6b-dca71a0b31ba","Technology assessment","Mulder, K.F.","","2012","De toekomst is misschien wel belangrijker dan onze geschiedenis. Of je nu student bent, ambtenaar op een ministerie of in een kleine gemeente, een technostarter, innovatiemanager bij een groot bedrijf, de toekomst is een uiterst belangrijk speelveld.","","nl","book chapter","Van Gorcum","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:b945549c-7a95-4266-9863-e6558a76e066","http://resolver.tudelft.nl/uuid:b945549c-7a95-4266-9863-e6558a76e066","Laten we het een park noemen","Mulder, A.","","2011","","","nl","journal article","Forum, Vereniging voor Volkshuisvesting","","","","","","","","Architecture","Real Estate and Housing","","","",""
"uuid:d44af573-11b9-45bc-a4b1-7e4c70688fa7","http://resolver.tudelft.nl/uuid:d44af573-11b9-45bc-a4b1-7e4c70688fa7","De illusie van kredietcreatie","Mulder, N.; Peek, G.J.","","2011","Sinds het uitbreken van de crisis in 2008 proberen overheden wereldwijd krampachtig de economische groei en werkgelegenheid in hun land in stand te houden. Door grootschalige fiscale en monetaire stimuleringspakketten staat op dit moment de houdbaarheid van overheidsfinanciën van veel landen onder grote druk terwijl de economie nog geen zelfstandig groeipad is ingeslagen.","","nl","journal article","","","","","","","","","Architecture","Real Estate and Housing","","","",""
"uuid:66a3c65d-4e74-45ca-8e83-7551b4663bca","http://resolver.tudelft.nl/uuid:66a3c65d-4e74-45ca-8e83-7551b4663bca","Transition in public participation in Chinese water management","Song, X.; Mulder, K.F.; Frostell, B.; Ravesteyn, W.; Wennersten, R.","","2011","","","en","journal article","ICE Publishing","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:f24c20d7-ef08-456d-9edf-bf98ae492e54","http://resolver.tudelft.nl/uuid:f24c20d7-ef08-456d-9edf-bf98ae492e54","Hoe kwetsbaar is het Nederlandse wegennetwerk?","Snelder, M.; Drolenga, H.; Mulder, M.","","2011","Verstoringen op de weg, zoals incidenten, kunnen tot onverwacht grote vertragingen van soms wel meer dan een uur per persoon leiden. Dit geeft aan dat het wegennet kwetsbaar (niet robuust) is. In 2009 heeft Rijkswaterstaat een begrippenkader en indicatoren voor robuustheid opgesteld (Snelder et al., 2009). Hierbij is robuustheid gedefinieerd als de mate waarin een wegsysteem zijn functie kan behouden bij verstoringen, opdat er voor de weggebruiker geen onverwacht groot reistijdverlies optreedt. Als indicator is de extra reistijd als gevolg van verstoringen gekozen. Dit paper gaat in op de vraag hoe deze indicator kan worden geoperationaliseerd. Operationalisering betekent enerzijds dat de indicator uit data moet kunnen worden afgeleid en anderzijds dat de indicator met behulp van een model moet kunnen worden uitgerekend. De methode voor data-analyse staat centraal in dit paper. Hierbij is zowel naar de kans op incidenten gekeken als naar het gevolg. Een uitgebreide analyse van verschillende incidentdatabases geeft aan wat de kans is op verschillende soorten incidenten op verschillende wegen. Het blijkt dat wanneer gekeken wordt naar type wegvak, het incidentrisico voor een afrit het hoogst is, daarna volgen de oprit, weefvak/splitsing en het normale wegvak. Voor de normale wegvakken geldt in grote lijnen dat het incidentrisico afneemt naar gelang het aantal rijstroken toeneemt. Een kwaliteitstoets van de gevonden waarden geeft aan dat het noodzakelijk is om meer verklarende factoren voor het al dan niet optreden van een incident te vinden. Naast de kans op incidenten is het gevolg van belang. Incidenten hebben netwerkbrede effecten. Een incident kan tot file en dus vertraging op de weg zelf (1) en op andere wegen (2) leiden. Daarnaast wordt reistijdverlies geleden door mensen die besluiten om te rijden (3) en door extra files op de alternatieve routes (4). Tot slot kunnen kijkfiles optreden (5), zijn stroomafwaarts van het incident effecten te meten (6) en kan vraaguitval optreden (7). Dit paper beschrijft een methode waarmee op basis van twee nieuwe innovatieve data-analyse tools een nauwkeurige inschatting kan worden gemaakt van effect 1, 2, 5 en 6. Aan de hand van enkele voorbeelden wordt duidelijk gemaakt hoe de methode werkt. Bovendien zijn de geaggregeerde resultaten van een analyse van een deel van de incidenten die in 2009 plaatsvonden weergegeven. Hieruit blijkt onder andere dat het niet meenemen van fileterugslageffecten bij incidenten waarbij een maatregel is genomen (bijvoorbeeld het afkruisen van een rijstrook) kan leiden tot een onderschatting van 35% van het reistijdverlies.","","nl","conference paper","CVS","","","","","","","","Civil Engineering and Geosciences","Transport & Planning","","","",""
"uuid:bcd7ce58-2804-4242-873c-e219a8ebcb5f","http://resolver.tudelft.nl/uuid:bcd7ce58-2804-4242-873c-e219a8ebcb5f","Method of steering a vehicle","Della Penna, M.; Van Passen, M.M.; Abbink, D.A.; Mulder, M.","","2011","Vehicle and method of steering such a vehicle, wherein the vehicle has a steering wheel and steerable driving wheels and a transfer system for converting steering wheel actions to a steering angle of the steerable driving wheels, and wherein the transfer system is provided with a predefined stiffness value that determines said transfer system's transfer characteristic pertaining to a required amount of torque that is required in turning the steering wheel to effect a desired steering angle of the steerable driving wheels. In this vehicle and method of steering this vehicle, an area in front of the vehicle is monitored for detecting objects that the vehicle may hit when it continues its current path of movement. Depending on the detection of any such object the stiffness value of the transfer system is reduced so as to ease turning the steering wheel for effecting the desired steering angle of the steerable driving wheels.","","en","patent","European Patent Office","","","","","","","","Mechanical, Maritime and Materials Engineering","Biomechanical Engineering","","","",""
"uuid:2261aaac-afb4-48b4-a0b4-c482efab23c8","http://resolver.tudelft.nl/uuid:2261aaac-afb4-48b4-a0b4-c482efab23c8","Fractal disperse hydrogen sorption kinetics in spark discharge generated Mg/NbOx and Mg/Pd nanocomposites","Anastasopol, A.; Pfeiffer, T.V.; Schmidt-Ott, A.; Mulder, F.M.; Eijt, S.W.H.","","2011","Isothermal hydrogen desorption of spark discharge generated Mg/NbOx and Mg/Pd metal hydride nanocomposites is consistently described by a kinetic model based on multiple reaction rates, in contrast to the Johnson-Mehl-Avrami-Kolmogorov [M. Avrami, J. Phys. Chem. 9, 177 (1941); W. A. Johnson and R. F. Mehl, Trans. Am. Inst. Min., Metal. Eng. 135, 416 (1939); A. N. Kolmogorov, Izv. Akad. Nauk SSSR, Ser. Mat. 3, 355 (1937); F. Liu, F. Sommer, C. Bos, and E. J. Mittemeijer, Int. Mat. Rev. 52, 193 (2007)] model which is commonly applied to explain the kinetics of metal hydride transformations. The broad range of reaction rates arises from the disperse character of the particle size and the dendritic morphology of the samples. The model is expected to be generally applicable for metal hydrides which show a significant variation in particle sizes, in configuration and/or chemical composition of local surroundings of the reacting nanoparticles.","chemical analysis; chemical reactions; desorption; magnesium; magnesium compounds; nanocomposites; niobium compounds; palladium; particle size; plasma materials processing; sparks","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","","","","",""
"uuid:77aaf94f-0aba-4848-b15a-a1404cd66cde","http://resolver.tudelft.nl/uuid:77aaf94f-0aba-4848-b15a-a1404cd66cde","Design of an Airborne Three-Dimensional Separation Assistance Display","Ellerbroek, J.; Visser, M.; Van Dam, S.B.J.; Van Paassen, M.M.; Mulder, M.","","2011","In the context of the Next Generation Air Transportation System and Single European Sky ATM Research future airspace programs, this paper describes a concept for an airborne separation assurance display that is designed to aid pilots in their task of self-separation, by visualizing the possibilities for conflict resolution that the airspace provides. This paper is part of an ongoing research toward an ecological design of a separation assistance interface that can present all the relevant properties of the spatiotemporal separation problem. A work-domain analysis is described from which several perspective projections of traffic properties and travel constraints are derived. A display concept is proposed that presents heading and altitude action possibilities in a flight-path angle-track angle action space. Key issues in the current design are discussed, with recommendations for future work.","Ecological Interface Design (EID); Airborne Separation Assistance System (ASAS); self-separation; situation awareness","en","journal article","IEEE","","","","","","","","Aerospace Engineering","Control and Operations","","","",""
"uuid:cc02f8c2-ab7f-4b76-9e6d-beaf9cb7360b","http://resolver.tudelft.nl/uuid:cc02f8c2-ab7f-4b76-9e6d-beaf9cb7360b","Hysteresis in the nonmonotonic electric response of homogeneous and layered unconsolidated sands under continuous flow conditions with water of various salinities, 100 kHz to 2 MHz","Kavian, M.; Slob, E.C.; Mulder, W.A.","","2011","We measured the electric parameters for four different configurations of unconsolidated homogeneous and layered sands as a function of frequency, water saturation, and salinity under fluid flow conditions. Our objective is to determine if the effect of heterogeneities at scales much smaller than the skin depth can be captured by introducing effective frequency?dependent electrical values whose behavior can be described by simple functions. We employed the parallel plate capacitor technique to measure the complex impedance over a broad frequency range, from 100 kHz up to 3 MHz. We conducted main drainage and secondary imbibition cycles at atmospheric pressure and temperatures between 21°C and 22°C. The hysteretic effect in the real part of the effective complex permittivity at higher concentrations of NaCl is more pronounced for the homogeneous configurations than for the heterogeneous samples. Effective medium theory works well for dry and saturated layered sand, when the NaCl solution concentration is 1 mmol/l. It fails for fully saturated layered sands at salinities of 10 mmol/l or more. It also does not work for partially saturated sands, independent of salinity. A description of the electric properties of a layered sand at all saturation levels by means of an effective homogeneous medium will therefore require a dependence on frequency, saturation level, and salinity of the pore fluid. An extended version of the Cole?Cole model fits the nonmonotonic behavior of the real part of permittivity versus saturation.","Cole?Cole model; complex permittivity; fluid flow; hysteresis; unconsolidated layered sand","en","journal article","American Geophysical Union","","","","","","","2012-02-27","Civil Engineering and Geosciences","Geotechnology","","","",""
"uuid:c60c9158-3a23-4381-aa6d-ecb04c8d071d","http://resolver.tudelft.nl/uuid:c60c9158-3a23-4381-aa6d-ecb04c8d071d","Trajectory Optimization Based on Interval Analysis","De Weerdt, E.; Van Kampen, E.; Chu, Q.P.; Mulder, J.A.","","2011","Trajectory optimization has been a large field of research for many years. The drawback is that for non-convex, constrained problems practically all available solvers cannot guarantee that the globally optimal trajectory is found. Interval analysis based solvers however can provide this guarantee. Interval analysis has been applied to trajectory optimization before, but the previously presented methods suffered from major drawbacks which limited their application to small scale problems. In this paper a new interval based method is introduced which incorporates state parameterization to prevent explicit integration. The performance of the proposed method is demonstrated by applying it to a spacecraft formation flying optimization problem. The results are compared with a gradient based solver and it is shown that the interval method is guaranteed to find the global optimal solution. Finally the first steps for another new trajectory optimization method based on interval analysis and direct collocation are presented.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:a52acbf0-dfa5-4aeb-9def-d72116cc0e12","http://resolver.tudelft.nl/uuid:a52acbf0-dfa5-4aeb-9def-d72116cc0e12","Tuning Models of Pilot Tracking Behavior for a Specific Simulator Motion Cueing Setting","Pool, D.M.; Damveld, H.J.; Van Paassen, M.M.; Mulder, M.","","2011","This paper describes the preliminary results of an effort to compile data from a large number of studies that investigated the effects of variations in motion filter settings on pilot behavior. The main objective of this study is to formulate a set of mathematical rules that will allow for the tuning of behavioral pilot models to a certain motion cueing setting. To achieve this, data for different dependent measures such as tracking performance, pilot-vehicle system crossover frequencies, and pilot model parameters, taken from ten different experiments that considered pilot tracking behavior under varying rotational or translational motion cueing settings, has been combined. By checking the correlation of the variation in any of these dependent measures and parameters that quantify the applied variation in motion cueing, a number of consistent relations has been identified. The most consistent and clear effects that are found from this analysis are variations in some important dependent measures with the motion filter gain at 1 rad/s. Over the full range of motion filter gains at 1 rad/s from 0 to 1, a reduction in pilot visual gain of around 20% is observed with reducing motion filter gain, in combination with a 30% increase in the amount of visual lead equalization adopted by pilots.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:37a38ce1-8d62-4ce0-af1c-a57506b2ed80","http://resolver.tudelft.nl/uuid:37a38ce1-8d62-4ce0-af1c-a57506b2ed80","Effects of Heave Washout Filtering on Motion Fidelity and Pilot Control Behavior for a Large Commercial Airliner","Van Wieringen, A.T.; Pool, D.M.; Van Paassen, M.M.; Mulder, M.","","2011","Due to the significant translational heave motion at the pilot station associated with changes in aircraft pitch attitude, themotion cueing for aircraft pitchmaneuvering typically requires significant heave washout filtering. Previous studies that attempted to motivate choices in the motion cueing strategy for pitch maneuvering based on measurements of pilot behavior. For the small conventional aircraft considered in these studies, the results indicated that, despite the fact that pilots were found to adapt their control strategy to changes in heave cueing, the pitch rotation had a dominant influence on pilot behavior during pitch tracking. For large commercial airliners, a relevant application of this research as a lot of commercial pilot training occurs on moving-base simulators, the location of the pilot station is significantly further from the center of aircraft pitch rotation, yielding more pronounced heave motion cues during changes in pitch attitude. This difference, in addition to typically slower pitch dynamics that require more lead equalization, implies the best choice in motion cueing for large aircraft may be significantly different from what would be optimal for smaller aircraft. In this paper, an experiment is described in which pilot behavior is measured in a pitch attitude disturbance-rejection task with a controlled element and motion cueing conditions that are representative for a Boeing 747 aircraft. Different third-order heave washout filter settings were considered, in addition to a variation in the presence of 1-to-1 rotational pitch motion. Significant effects of the applied variation in pitch and heave motion cueing are observed, even though the effect of heave motion feedback is indeed found to be comparatively more important for larger aircraft. Furthermore, a heave motion filter that combined a low gain with low filter phase distortion was found to yield the least effect on pilot behavior, while for heave motion filters with a relatively high gain and high break frequency significantly larger contributions of motion feedback to pilot behavior were observed.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:8f4c87ce-fdea-48cd-834b-a30f47c4fe93","http://resolver.tudelft.nl/uuid:8f4c87ce-fdea-48cd-834b-a30f47c4fe93","Effect of Performing a Boundary-Avoidance Tracking Task on the Perception of Coherence Between Visual and Inertial Cues","Valente Pais, A.R.; Van Paassen, M.M.; Mulder, M.; Wentink, M.","","2011","During flight simulation, the inertial and visual stimuli provided to the pilot differ considerably. For successful design of motion cueing algorithms it is necessary to gather knowledge on how pilots perceive the difference between visual and inertial cues. Some of the work done on this topic has concentrated on the concept of coherence zone. A coherence zone represents a range of inertial motion amplitudes, which although not being a match with the visual motion, are still perceived by humans as one realistic, coherent movement. To extend the knowledge on coherence zones an experiment was performed that tested the yaw motion coherence zone limits at two frequencies during passive and active situations. Subjects were required to perform a boundary-avoidance task as a mean to decrease the attention given to the perception task. This decrease in attention was thought to cause a widening of the perceived coherence zones. The boundary-avoidance tracking task had two levels of difficulty. The measured coherence zones did not change significantly with the addition of the control task. These results imply that unlike motion perception thresholds, coherence zones are little influenced by decreased levels of attention. This being true, for a range of tasks, such as supervisory tasks or procedural training in a flight simulator, pilot acceptance of the inertial cues might be measured in a passive manner and directly applied to the active scenario.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:34ec47a4-378c-498f-be60-dfe74ee53991","http://resolver.tudelft.nl/uuid:34ec47a4-378c-498f-be60-dfe74ee53991","Re-design of an Inbound Planning Interface for Air Traffic Control","Klomp, R.E.; Mulder, M.; Van Paassen, M.M.; Roerdink, M.I.","","2011","In the coming decades, the task of an air traffic controller is expected to shift to one of strategic, trajectorybased air traffic management. This form of air traffic control is no longer possible without the help of automated support tools. In previous research, it has been shown that the time-space diagram, combined with a conventional plan view display is a good candidate for supporting an air traffic controller with the inbound planning task in the future situation. However, in this initial study, the vertical plane was not yet fully included. Secondly, during an initial validation experiment, creating and maintaining a ’mental picture’ of the traffic was reported to be a difficult task. These findings lead to the re-design of the interface in the current research, which focuses on implementing the vertical plane and improving the integration of information across the successive displays. An experiment has been performed with a PC-based simulation which validates that the enhanced interface can be used to manage the air traffic safely and efficiently. Secondly, it has been shown that the ability to manipulate the speed of an aircraft in the adjacent sector can significantly increase situation awareness and reduce controller workload.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:4a16c66d-0ea1-4a66-be0b-e4a678ba428d","http://resolver.tudelft.nl/uuid:4a16c66d-0ea1-4a66-be0b-e4a678ba428d","Time-based Spacing for 4D Approaches using Speed-Profiles","De Jong, P.M.A.; De Vos, K.; Borst, C.; Van Paassen, M.M.; Mulder, M.","","2011","Two of the major projects in ATM development, SESAR and NextGen, both fore- cast the use of 4D trajectories as an intermediate phase in the development of full Performance Based Trajectories. Using 4D trajectories, the full positional and time coordinates of the aircraft are known throughout the planned trajectory. During approach, when reduced separation minimums are applied, the accuracy of this profile is most important to ensure a safe approach to the runway. One implementation of 4D approaches is by using Required-Time of Arrival (RTA) to separate aircraft during approach. The latest Flight Management Computers are capable of calculating a flight-path w.r.t. to a RTA. This paper describes the amount of time error that can occur during approaches where an RTA is set at the runway threshold that could still be resolved by increasing or decreasing the speed-profile. The minimum and maximum bounds are referred to as control space. Using simulations, the recoverable time error is calculated. Lateral trajectories from Amsterdam Airport Schiphol, different wind conditions and two different aircraft types were included to investigate different factors influencing the time error, such as aircraft type, speed restrictions and wind. Finally, the paper discusses a new method to control time-based spacing using a closed-loop speed controller.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:ef22d8e0-e221-4da9-b863-6ebf15abccf1","http://resolver.tudelft.nl/uuid:ef22d8e0-e221-4da9-b863-6ebf15abccf1","Relationship Between Optimal Gain and Coherence Zone in Flight Simulation","Correia Gracio, B.J.; Valente Pais, A.R.; Van Paassen, M.M.; Mulder, M.; Kelly, L.C.; Houck, J.A.","","2011","In motion simulation the inertial information generated by the motion platform is most of the times different from the visual information in the simulator displays. This occurs due to the physical limits of the motion platform. However, for small motions that are within the physical limits of the motion platform, one-to-one motion, i.e. visual information equal to inertial information, is possible. It has been shown in previous studies that one-to-one motion is often judged as too strong, causing researchers to lower the inertial amplitude. When trying to measure the optimal inertial gain for a visual amplitude, we found a zone of optimal gains instead of a single value. Such result seems related with the coherence zones that have been measured in flight simulation studies. However, the optimal gain results were never directly related with the coherence zones. In this study we investigated whether the optimal gain measurements are the same as the coherence zone measurements. We also try to infer if the results obtained from the two measurements can be used to differentiate between simulators with different configurations. An experiment was conducted at the NASA Langley Research Center which used both the Cockpit Motion Facility and the VisualMotion Simulator. The results show that the inertial gains obtained with the optimal gain are different than the ones obtained with the coherence zone measurements. The optimal gain is within the coherence zone.The point of mean optimal gain was lower and further away from the one-to-one line than the point of mean coherence. The zone width obtained for the coherence zone measurements was dependent on the visual amplitude and frequency. For the optimal gain, the zone width remained constant when the visual amplitude and frequency were varied. We found no effect of the simulator configuration in both the coherence zone and optimal gain measurements.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:2cc80325-5122-4cb9-bbb1-9f1e6f65afa4","http://resolver.tudelft.nl/uuid:2cc80325-5122-4cb9-bbb1-9f1e6f65afa4","Real-time Wind Profile Estimation using Airborne Sensors","In 't Veld, A.C.; De Jong, P.M.A.; Van Paassen, M.M.; Mulder, M.","","2011","Wind is one of the major contributors to uncertainty in continuous descent approach operations. Especially when aircraft that are flying low or idle thrust approaches are issued a required time of arrival over the runway threshold, as is foreseen in some of the future ATC scenarios, the on-board availability of both dependable and accurate wind estimates becomes a necessity. This paper presents a method for real-time estimation of a wind profile in the terminal maneuvering area, based on data transmissions of nearby aircraft that produces real-time wind profile estimates in a form that is usable for accurate trajectory estimation. The wind estimation algorithm is designed to process data that is of the form currently used in the Aircraft Meteorological Data Relay (AMDAR)-program. The algorithm combines a stochastic estimation based on this data and a traditional logarithmic estimator in order to be able to produce a valid estimation even when there are no data available from other aircraft.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:730597cd-cf1a-493f-97b1-fa903d4e4c0e","http://resolver.tudelft.nl/uuid:730597cd-cf1a-493f-97b1-fa903d4e4c0e","Adaptive Optimizing Nonlinear Control Design for an Over-actuated Aircraft Model","Van Oort, E.R.; Sonneveldt, L.; Chu, Q.P.; Mulder, J.A.","","2011","In this paper nonlinear adaptive flight control laws based on the backstepping approach are proposed which are applicable to over-actuated nonlinear systems. Instead of solving the control allocation exactly, update laws for the desired control effector signals are defined such that they converge to the optimal solution. Stability and boundedness of the resulting closed-loop system can be shown by means of Lyapunov analysis. Three different update laws are defined, the integrated, modular and composite adaptive designs. The last can be seen as a combination between the first two and has the best convergence and numerical properties. Second-order actuator dynamics are taken into account in the control designs. The control design is evaluated using numerical simulations where several cases of locked control surface failures are considered during two different maneuvers. No sensor information about these failures is fed back to the control system. The tracking performance of the adaptive control design is excellent for the nominal case and all considered failure cases. The failures are recognized shortly after they are introduced into the system, and the new dynamics are rapidly identified.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:fa6f33db-ebf6-4ec0-9b1d-b87abdba1e23","http://resolver.tudelft.nl/uuid:fa6f33db-ebf6-4ec0-9b1d-b87abdba1e23","Validating the Multidimensional Spline Based Global Aerodynamic Model for the Cessna Citation II","De Visser, C.C.; Mulder, J.A.","","2011","The validation of aerodynamic models created using flight test data is a time consuming and often costly process. In this paper a new method for the validation of global nonlinear aerodynamic models based on multivariate simplex splines is presented. This new method uses the unique properties of the multivariate simplex splines, a recent type of of multivariate spline, to speedup the process of aerodynamic model validation. Multivariate simplex splines are defined on non-rectangular domains and can be used to accurately fit scattered nonlinear datasets in any number of dimensions. The simplex splines consist of piecewise defined, ordinary multivariate polynomials with a predefined continuity between neighboring polynomial pieces. A recent method for nonlinear system identification based on multivariate simplex splines was used to create a global nonlinear aerodynamic model of the Cessna Citation II laboratory aircraft operated by the Delft University of Technology. In this paper, the multivariate spline based aerodynamic model for the pitching moment coefficient will be validated using both a model residual analysis as well as a statistical model quality analysis. It will be demonstrated that these new analysis methods, which are both unique to the multivariate simplex splines, provide a highly efficient and powerful new method for aerodynamic model validation.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:c452bdd8-e869-46ec-951f-20bf68b0281c","http://resolver.tudelft.nl/uuid:c452bdd8-e869-46ec-951f-20bf68b0281c","Phase Coherence Zones in Flight Simulation","Jonik, P.M.; Valente Pais, A.R.; Van Paassen, M.M.; Mulder, M.","","2011","In flight simulation detailed knowledge of human motion perception is crucial. Phase differences between inertial and visual motion introduced by motion filters might have negative effects on the fidelity of flight simulation. This study investigated human visual- vestibular phase-error detection. An experiment was conducted to measure the maximum amount of phase lead of the inertial motion with respect to the visual motion that remains undetected by the human. It contributes to the assessment of so-called coherence zones investigated in previous studies. Possible effects of the stimulus frequency, amplitude and the axis of rotation were examined. They were found to have no significant influence on phase-error detection. The average phase-error threshold was determined at 22 degrees. In accordance to previous studies the results showed that humans can be considered more like phase-error detectors rather than time delay detectors.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:7cb7aac9-0921-4e12-948f-0ae64aa4bd02","http://resolver.tudelft.nl/uuid:7cb7aac9-0921-4e12-948f-0ae64aa4bd02","Continuous Descent Approaches with Variable Flight-Path Angles under Time Constraints","Sopjes, R.; De Jong, P.M.A.; Borst, C.; Van Paassen, M.M.; Mulder, M.","","2011","In order to reduce noise nuisance around Schiphol Airport, a Continuous Descent Approach procedure was introduced in the late ’90s. Unfortunately, because unpredictable individual aircraft behavior lead to increased landing intervals for this procedure, it is currently only applied during night time operations. Time-of-Arrival control in the terminal area could reduce the landing interval for this procedure. The research presented in this paper investigates the influence of multiple segments with different flight-path angles on the time of arrival. A new procedure with Variable Flight-path angle (VFA) involving active planning of the approach from the pilot through a pilot support interface, presented in the Vertical Situation Display. A preliminary pilot-in-the-loop evaluation was conducted, to investigate pilot performance, workload and interface usability. Three scenarios were tested, all with different Required Time of Arrival. Workload was low for all scenarios and performance good for the two scenarios with early arrival times. For the scenario with a late arrival time, performance was mediocre. Changes in representation of the flap and gear cues and the addition of Estimated Time of Arrival information might improve the performance.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:b1824ee4-f604-4d9f-8d21-ac3362740cd5","http://resolver.tudelft.nl/uuid:b1824ee4-f604-4d9f-8d21-ac3362740cd5","Using the Solution Space Diagram in Measuring the Effect of Sector Complexity During Merging Scenarios","Abdul Rahman, S.M.B.; Van Paassen, M.M.; Mulder, M.","","2011","When designing Air Traffic Control (ATC) sectors and procedures, traffic complexity and workload are important issues. For predicting ATC workload, metrics based on the Solution Space Diagram (SSD) have been proposed. This paper studies the effect of sector design on workload and SSD metrics. When considering the SSD in evaluation of a sector, each aircraft within the sector introduces a zone of conflict, the Forbidden Beam Zone (FBZ), on the SSD. The properties of these FBZ are systematically studied to increase understanding of the SSD usability in assessing workload and sector complexity. The effects of sector design variables on Air Traffic Controller (ATCo) workload and also SSD properties were evaluated. Example of sector properties are, number of streams to be merged, the merge angle, the proximity of incoming aircraft and the variability of traffic mix of small and large aircraft. Based on the findings, each sector design variable leads to different effect on both workload and SSD properties. Apart from that, correlation between the workload and the SSD properties were found to be in a higher level than of the number of aircraft within the sector, proving that the SSD-based analysis to be a good workload indicator. These correlations were studied based on two different groups of subjects with ranging experience in order to demonstrate the robustness of the method.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:3bc425c0-5001-489e-a5a6-e89a8a39234e","http://resolver.tudelft.nl/uuid:3bc425c0-5001-489e-a5a6-e89a8a39234e","A Time-Space Diagram as Controller Support Tool for Closed Path Continuous Descent Operations","De Leege, A.M.P.; In 't Veld, A.C.; Mulder, M.; Van Paassen, M.M.","","2011","Tactical control during a closed-path Continuous Descent Operation stops the aircraft from following its optimized descent. To mitigate tactical control, air traffic controllers apply arbitrary large spacing buffers to account for the unpredictability of the aircraft trajectory from the controller’s point of view. A controller support tool is required for early de-confliction, spacing, and sequencing to facilitate these operations without the need to apply large buffers. The Time-Space Diagram controller support tool was developed to make the constraints and complexity of a Continuous Descent Operation perceptually evident and provide tools and information to the controller to be an active problem solver. This paper addresses the further development and validation of the interface. The concept of Visual Momentum was applied to enhance the efficiency of working the multi-display interface that consists of the Plan View Display and Time-Space Diagram. Direct Manipulation Interfaces were added to enable the controller to plan and implement actions, such as speed and altitude control. A controller-in-the-experiment was setup to validate the interface. In the experiment the subjects used either the Time-Space Diagram support tool or a stack list that provided the required spacing and time to lose or gain as a baseline. Both interfaces enabled the subjects to space the aircraft safely and efficiently. Compared to the baseline, the Time-Space Diagram interface freed time to plan traffic ahead using the Direct Manipulation Interfaces, which according to all subjects worked intuitively. The number of instructions per aircraft was decreased by 25%. Early accurate speed control was applied and use of heading vectors was no longer necessary in most scenarios. As a result aircraft commenced their continuous descent at a higher altitude and greater distance from the runway. The controller workload was significantly reduced and the level of Situational Awareness increased.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:89ca486e-9a03-4f87-be11-3c8fc74e7879","http://resolver.tudelft.nl/uuid:89ca486e-9a03-4f87-be11-3c8fc74e7879","Heritage and its role in revitalising the housing market","Mulder, A.","","2011","Due to the demise of traditional industry large industrial estates, often at central locations, become available for reuse. Municipalities have reacted by trying to attract new users who would need a lot of space, like big shopping centres, while strengthening the urban economy. However, these attempts have not always been successful. Also, local people may feel alienated if all remnants of the past, in which they lived and worked, are ignored. In the recent past, some attempts were made to re-use buildings in a way more connected to the history of the area. The IBA Emscher Park (in the German Ruhr area) experimented in the 1990s with a less intensive use of industrial estates, while at the same time keeping many of the buildings standing and involving the local communities. The Ruhr area cities now are something of a tourist attraction, something that no-one could have predicted during the age of smoke and dust. Less well known is the fact that the refurbishment and new building of 30 garden cities was also part of the IBA. Chimney Pot Park in the English city of Salford (Greater Manchester) also built on local traditions. Facades of terraced houses were kept, but behind them new homes with uncommon layouts were created: an attempt to reconcile the traditions of a working class estate with ‘new urban living’ (including alternative household formations) to the area. In this paper, the increased role of heritage as a way to help revitalising the housing market of shrinking of cities will be explored.","shrinking cities; housing market; government policy; industrial heritage; Germany; England","en","conference paper","ENHR","","","","","","","","Architecture","","","","",""
"uuid:926233cb-d999-41f5-86a6-4ce19965dce5","http://resolver.tudelft.nl/uuid:926233cb-d999-41f5-86a6-4ce19965dce5","Differential constraints for bounded recursive identification with multivariate splines","De Visser, C.C.; Chu, Q.P.; Mulder, J.A.","","2011","The ability to perform online model identification for nonlinear systems with unknown dynamics is essential to any adaptive model-based control system. In this paper, a new differential equality constrained recursive least squares estimator for multivariate simplex splines is presented that is able to perform online model identification and bounded model extrapolation in the framework of a model-based control system. A new type of linear constraints, the differential constraints, are used as differential boundary conditions within the recursive estimator which limit polynomial divergence when extrapolating data. The differential constraints are derived with a new, one-step matrix form of the de Casteljau algorithm, which reduces their formulation into a single matrix multiplication. The recursive estimator is demonstrated on a bivariate dataset, where it is shown to provide a speedup of two orders of magnitude over an ordinary least squares batch method. Additionally, it is demonstrated that inclusion of differential constraints in the least squares optimization scheme can prevent polynomial divergence close to edges of the model domain where local data coverage may be insufficient, a situation often encountered with global recursive data approximation.","multivariate splines; parameter estimation; scattered data; function approximators","en","journal article","Elsevier","","","","","","","2014-05-01","Aerospace Engineering","Control & Operations","","","",""
"uuid:45d5a8f6-efed-4a6c-adec-28ae9d1c4de7","http://resolver.tudelft.nl/uuid:45d5a8f6-efed-4a6c-adec-28ae9d1c4de7","System integration: Condition for success. The case of Hammarby Sjöstad and Eva-Lanxmeer","Vernay, A.L.; Pandis, S.; Saldeco Rahola, T.B.; Mulder, K.; Brandt, N.","","2011","Today, many new urban areas, such as cities, towns, villages, or districts, are being built worldwide and their completion requires the development of a number of infrastructures. Traditionally, these infrastructures are planned in parallel. However, increased environmental awareness is pushing cities to improve their environmental performance. One way to do so is by systems integration (e.g. connecting drinking water pumping with energy production). The aim of this paper is to show how different actor networks lead to different process of integration. We especially focus on the influence of actor participation during the design phase. To do so, two case studies are presented: Hammarby Sjöstad in Sweden and EVALanxmeer in the Netherlands.","systems integration; sustainable urban development; techno-economic network","en","conference paper","Delft University of Technology","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:fb992a64-6a35-4c1e-ad5a-bdb5d8efa746","http://resolver.tudelft.nl/uuid:fb992a64-6a35-4c1e-ad5a-bdb5d8efa746","Effects of the airwave in time-domain marine controlled-source electromagnetics","Hunziker, J.W.; Slob, E.C.; Mulder, W.","","2011","In marine time-domain controlled-source electromagnetics (CSEM), there are two different acquisition methods: with horizontal sources for fast and simple data acquisition or with vertical sources for minimizing the effects of the airwave. Illustrations of the electric field as a function of space and time for various source antenna orientations, based on analytical formulation of the electric field in two half-spaces, provide insights into the properties of the airwave and the nature of diffuse electric fields. Observing the development of the electric field over time and space reveals that diffusive fields exhibit directionality. Therefore, techniques that have thus far mostly been applied to wavefields can be adapted for CSEM. Examples range from the well-known up-down decomposition to beam steering. Vertical sources have the advantage of not creating an airwave. On the other hand, it is quite difficult to achieve perfect verticality of the source antenna. Results, using a numerically modeled data set to analyze the impact of the airwave on a signal from a subsurface reservoir in the case of a slightly dipping vertical source, indicate that already for a dip of 0.05, the airwave contributes 20% to the complete electric field in our configuration of reservoir depth, water thickness, and conductivity values.","antennas; data acquisition; electrical conductivity; geophysical equipment; geophysical prospecting; hydrocarbon reservoirs; rocks; seafloor phenomena","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:0aef239b-320f-43ba-a3aa-859638090169","http://resolver.tudelft.nl/uuid:0aef239b-320f-43ba-a3aa-859638090169","Zandmotor (sand motor): Building with nature","Mulder, J.P.M.; Stive, M.J.F.","","2011","Our coast essentially consists of sand from the bottom of the North Sea that was laid there by rivers in previous interglacial periods. Increasing sea levels have meant that this source has gradually almost ceased to exist with build-up reversing to break down. The balance between the supply and demand for sediment is currently negative but sand supplementation can restore this balance. By scaling up supplementation we can ‘Build with Nature’ and so grow in a natural way as the sea level rises and even if it rises more quickly. Along the Delft coastline there is currently an ongoing experiment with a large scale ‘Zandmotor’ which will ensure longer term safety in an innovative way and also provide space for nature and recreation.","","en","conference paper","ICID","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:d3329269-df36-4c2e-b9f8-9bf5170a7311","http://resolver.tudelft.nl/uuid:d3329269-df36-4c2e-b9f8-9bf5170a7311","Exploiting the airwave for time-lapse reservoir monitoring with CSEM on land","Wirianto, M.; Mulder, W.A.; Slob, E.C.","","2011","In the application of controlled source electromagnetics for reservoir monitoring on land, repeatability errors in the source will mask the time-lapse signal due to hydrocarbon production when recording surface data close to the source. We demonstrate that at larger distances, the airwave will still provide sufficient illumination of the target. The primary airwave diffuses downward into the earth and then is scattered back to the surface. The time-lapse difference of its recorded signal reveals the outline on the surface of the resistivity changes in a hydrocarbon reservoir under production. However, repeatability errors in the primary airwave can destroy the signal-to-noise ratio of the time-lapse data. We present a simple and effective method to remove the primary airwave from the data, which we call partial airwave removal. For a homogeneous half space and a delta-function type of source, the surface expression of the airwave does not depend on frequency. For this reason, the primary airwave can be subtracted from the data using recordings at two frequencies, one low enough with a skin depth of the order of the reservoir depth that is sensitive to the reservoir, the other high enough to only sense the near surface. The method does not affect secondary airwave components created by signals that have propagated through the earth and returned to the surface. We show that the method provides a direct indicator of production-related time-lapse changes in the reservoir. We illustrate this for several models, including a general 3D heterogeneous model and one with strong surface topography, for situations where survey repeatability errors are large.","atmospheric electromagnetic wave propagation; geomagnetism; geophysical techniques; hydrocarbon reservoirs","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:cf9119d3-8bbf-489b-b734-f25c4cd1402a","http://resolver.tudelft.nl/uuid:cf9119d3-8bbf-489b-b734-f25c4cd1402a","Robust flight control using incremental nonlinear dynamic inversion and angular acceleration prediction","Sieberling, S.; Chu, Q.P.; Mulder, J.A.","","2010","This paper presents a flight control strategy based on nonlinear dynamic inversion. The approach presented, called incremental nonlinear dynamic inversion, uses properties of general mechanical systems and nonlinear dynamic inversion by feeding back angular accelerations. Theoretically, feedback of angular accelerations eliminates sensitivity to model mismatch, greatly increasing the robust performance of the system compared with conventional nonlinear dynamic inversion. However, angular accelerations are not readily available. Furthermore, it is shown that angular acceleration feedback is sensitive to sensor measurement time delays. Therefore, a linear predictive filter is proposed that predicts the angular accelerations, solving the time delay and angular acceleration availability problem. The predictive filter uses only references and measurements of angular rates. Hence, the proposed control method makes incremental nonlinear dynamic inversion practically available using conventional inertial measurement units.","dynamic inversion; nonlinear dynamic inversion; incremental nonlinear dynamic inversion; NDI; INDI; feedback linearization; robust flight control; angular acceleration prediction","en","journal article","AIAA","","","","","","","","Aerospace Engineering","Control and Simulation Division","","","",""
"uuid:a89a3ffd-db38-4148-92c8-1565102a07be","http://resolver.tudelft.nl/uuid:a89a3ffd-db38-4148-92c8-1565102a07be","A feasibility study of land CSEM reservoir monitoring in a complex 3-D model","Wirianto, M.; Mulder, W.A.; Slob, E.C.","","2010","","numerical approximations and analysis; downhole methods; electrical properties","en","journal article","Royal Astronomical Society","","","","","","","2011-07-01","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:b97b8a3b-28af-447f-a7c2-4cc6651042e3","http://resolver.tudelft.nl/uuid:b97b8a3b-28af-447f-a7c2-4cc6651042e3","Green's tensors for the diffusive electric field in a VTI half-space","Slob, E.C.; Hunziker, J.W.; Mulder, W.A.","","2010","","","en","journal article","EMW Publishing","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:2685766a-dcec-4d32-a1a2-bc410fa2331a","http://resolver.tudelft.nl/uuid:2685766a-dcec-4d32-a1a2-bc410fa2331a","Dispersive kinetics in discotic liquid crystals","Kruglova, O.; Mulder, F.M.; Kearley, G.J.; Picken, S.J.; Stride, J.A.; Paraschiv, I.; Zuilhof, H.","","2010","The dynamics of the discotic liquid-crystalline system, hexakis (n-hexyloxy) triphenylene (HAT6), is considered in the frame of the phenomenological model for rate processes proposed by Berlin. It describes the evolution of the system in the presence of the long-time scale correlations in the system, and we compare this with experimental quasielastic neutron scattering of the molecular assembly of HAT6 in the columnar phase. We interpret the parameters of this model in terms of nonextensive thermodynamics in which rare events in the local fast dynamics of some parts of the system control the slower dynamics of the larger molecular entity and lead to a fractional diffusion equation. The importance of these rare local events to the overall dynamics of the system is linked to the entropic index, this being obtained from the data within the model approach. Analysis of the waiting-time dependence from momentum transfer reveals a Lévy distribution of jump lengths, which allows us to construct the van Hove correlation function for discotic liquid-crystalline system.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:18028bc6-8069-4a1f-ae39-78ca34f38248","http://resolver.tudelft.nl/uuid:18028bc6-8069-4a1f-ae39-78ca34f38248","Seismic attenuation imaging with causality","Hak, B.; Mulder, W.A.","","2010","Seismic data enable imaging of the Earth, not only of velocity and density but also of attenuation contrasts. Unfortunately, the Born approximation of the constant-density visco-acoustic wave equation, which can serve as a forward modelling operator related to seismic migration, exhibits an ambiguity when attenuation is included. Different scattering models involving velocity and attenuation perturbations may provide nearly identical data. This result was obtained earlier for scatterers that did not contain a correction term for causality. Such a term leads to dispersion when considering a range of frequencies. We demonstrate that with this term, linearized inversion or iterative migration will almost, but not fully, remove the ambiguity. We also investigate if attenuation imaging suffers from the same ambiguity when using non-linear or full waveform inversion. A numerical experiment shows that non-linear inversion with causality convergences to the true model, whereas without causality, a substantial difference with the true model remains even after a very large number of iterations. For both linearized and non-linear inversion, the initial update in a gradient-based optimization scheme that minimizes the difference between modelled and observed data is still affected by the ambiguity and does not provide a good result. This first update corresponds to a classic migration operation. In our numerical experiments, the reconstructed model started to approximate the true model only after a large number of iterations.","OA-Fund TU Delft","en","journal article","Wiley","","","","","","","","Civil Engineering and Geosciences","Geotechnology","","","",""
"uuid:3846d2ce-aecc-4c7d-b2fc-892177301c23","http://resolver.tudelft.nl/uuid:3846d2ce-aecc-4c7d-b2fc-892177301c23","Pseudo Control Hedging and its Application for Safe Flight Envelope Protection","Lombaerts, T.J.J.; Looye, G.H.N.; Chu, Q.P.; Mulder, J.A.","","2010","This paper describes how the previously developed concept of Pseudo Control Hedging (PCH) can be integrated in a Fault Tolerant Flight Controller (FTFC) as a safe flight envelope protection system of the first degree. This PCH algorithm adapts the reference model for the system output in case of unachievable commands due to control input saturation. As an example, this algorithm has been applied in the pitch rate and velocity control loops of a high fidelity Boeing 747 simulation model where its beneficial influence has been illustrated. The nonlinear adaptive control law used for this example is a triple layered nonlinear dynamic inversion algorithm, based upon the concept of time scale separation.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:cdd395af-55b5-42e1-8f93-10b51c1dfbb1","http://resolver.tudelft.nl/uuid:cdd395af-55b5-42e1-8f93-10b51c1dfbb1","Implementation and validation of a model of the MPI Stewart platform","Nieuwenhuizen, F.M.; Van Paasen, M.M.; Mulder, M.; Bülthoff, H.H.","","2010","A simulated model of the MPI Stewart platform can be used to identify the influence of motion system characteristics on human control behaviour in active closed-loop control experiments on the SIMONA Research Simulator. In this paper, a previously identified model of the MPI Stewart platform was analysed with describing function measurements, and it was found that a reduced form of the model was sufficient to capture the relevant dynamics. The reduced model was simulated on the SIMONA Research Simulator and describing function measurements were performed with two IMUs. Both IMUs revealed a resonance peak in measurements of response magnitude at the highest frequencies. A reduced time delay was found with the newer IMU. With the describing function measurements, the implementation of the MPI Stewart platform model was validated in terms of the frequency response and the time delay.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:fcf4d3b2-9f3c-4fd1-8ec7-1c44d90a33e2","http://resolver.tudelft.nl/uuid:fcf4d3b2-9f3c-4fd1-8ec7-1c44d90a33e2","Optimization of Spacecraft Rendezvous and Docking using Interval Analysis","Van Kampen, E.; Chu, Q.P.; Mulder, J.A.","","2010","This paper applies interval optimization to the fixed-time multiple impulse rendezvous and docking problem. Current methods for solving this type of optimization problem include for example genetic algorithms and gradient based optimization. Unlike these methods, interval methods can guarantee that the globally best solution is found for a given parameterization of the input. The state transition matrix approach for the linearized CW-equations is used to avoid interval integration. Thruster pulse amplitudes are optimized by an interval branch and bound algorithm, which systematically eliminates parts of the control input space that do not satisfy the final time state constraints. Interval analysis is shown to be a useful tool in both sensitivity analysis and nonlinear optimization of the rendezvous and docking problem.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:fbc0a101-7bef-442b-b015-1e789bc31a70","http://resolver.tudelft.nl/uuid:fbc0a101-7bef-442b-b015-1e789bc31a70","Control Space Analysis of Three-Degree Decelerating Approaches at Amsterdam Airport Schiphol","De Jong, P.M.A.; In 't Veld, A.C.; De Leege, A.M.P.; Van Paassen, M.M.; Mulder, M.","","2010","Amsterdam Schiphol Airport currently uses a Continuous Descent Approach during night time operations only, due to reduced runway capacity caused by unpredictable individual aircraft behavior. The Three-Degree Decelerating Approach (TDDA) has been developed to increase predictability and runway capacity by switching the sepa- ration task from Air Traffic Control to the pilot on board the aircraft. The research described in this paper identifies the factors that influence the control space of aircraft performing a TDDA in a real-life setting. Control space is defined as the difference between the maximum and minimum duration to perform the TDDA. Using different control strategies, a fast approach or slow approach can be flown. A fast-time simulation tool was built to perform simulations with different aircraft types, initial weights, wind speeds and directions. Preliminary simulations indicate that a flap scheduler is needed to optimize control space, and the flap scheduling algorithm was enhanced to find optimal flap schedules for all wind conditions. The results of these simulations show that the influence of wind direction depends on aircraft aerodynamic characteristics, which mainly depend on the drag characteristics of the aircraft and aircraft weight. Furthermore, the results can be used to determine whether a TDDA can be executed using different aircraft and under different wind conditions.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:b46be62c-9272-4708-92ff-46f8d6135119","http://resolver.tudelft.nl/uuid:b46be62c-9272-4708-92ff-46f8d6135119","The Use of the Dynamic Solution Space to Assess Air Traffic Controller Workload","D'Engelbronner, J.G.; Mulder, M.; Van Paassen, M.M.; De Stigter, S.; Huisman, H.","","2010","Air traffic capacity is mainly bound by air traffic controller workload. In order to effectively find solutions for this problem, off-line pre-experimental workload assessment methods are desirable. In order to better understand the workload associated with air traffic control, previous research introduced the static Solution Space as a possible workload metric. The Solution Space Diagram is a mapping of intruding aircraft trajectories to the velocity/heading plane in the form of Conflict Zones and safe areas. Choosing a velocity vector in either one will provide an unsafe or a safe solution, respectively. In this paper an improved, dynamic Solution Space will be tested for correlations with air traffic controller workload, measured experimentally. A two dimensional experiment has been conducted, where subjects were required to line up all aircraft in a sector towards a certain waypoint, while continuously providing subjective workload ratings. High correlations were found between several Solution Space parameters and the subjective workload. Even though a conventional workload metric shows also to be highly correlated to the measured workload, the Solution Space could be the scenario independent workload metric that is currently missing in air traffic controller workload determination.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:045f1368-3964-4ac7-9626-fbb47da8f277","http://resolver.tudelft.nl/uuid:045f1368-3964-4ac7-9626-fbb47da8f277","A Multidimensional Spline Based Global Nonlinear Aerodynamic Model for the Cessna Citation II","De Visser, C.C.; Mulder, J.A.","","2010","A new method is proposed for the identification of global nonlinear models of aircraft non-dimensional force and moment coefficients. The method is based on a recent type of multivariate spline, the multivariate simplex spline, which can accurately approximate very large, scattered nonlinear datasets in any number of dimensions. The new identification method is used to identify a global nonlinear aerodynamic model of high dimensionality for the Cessna Citation II laboratory aircraft operated by the Delft University of Technology and the Netherlands National Aerospace Laboratory. The data used in the identification process consisted of millions of measurements and was accumulated during more than 250 flight test maneuvers with the laboratory aircraft. The resulting models for the aerodynamic force and moment coefficients are continuous analytical functions as they consist of sets of piecewise defined, multivariate polynomials. The identified models were validated using a subset of the flight data, with validation results showing a very close match between model and reality.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:87548511-912c-4c4c-adb9-cfdbd6ac48a0","http://resolver.tudelft.nl/uuid:87548511-912c-4c4c-adb9-cfdbd6ac48a0","The Effect of Synthetic Vision Enhancements on Landing Flare Performance","Le Ngoc, L.; Borst, C.; Mulder, M.; Van Paassen, M.M.","","2010","The usage of heads-down, non-conformal synthetic vision displays for landings below minimums has inherent problems during the flare due to minification effects. Literature showed that pilots can use four visual cues to perform a manual flare maneuver. Amongst their strategies, the Jacobson flare method seemed the most suitable to provide flare initiation and flare control cues. Offline, linear simulation results indicated that the Jacobson method was robust and its performance was comparable to an automatic landing system. An enhanced synthetic vision display was designed offering support cues to aid pilots with this landing method. An experiment was conducted in a fixed-based simulator with eight professional pilots and eight novice pilots. The enhanced display was tested against a basic version and conventional primary flight display with outside visuals. Each pilot group was split into two groups with different display orders to check for possible learning effects. The experiment showed that touchdown position was not affected by display type. The enhanced display did achieve softer touchdown sink rates compared to the basic version. The softest landings were done on outside visuals. A strong learning curve was also observed for the group of pilots that first flew with the enhanced display: this translated into better achieved performances with subsequent displays. Therefore, it could be a valuable tool for basic flight training and reduce the number of flight hours required in mastering the landing flare.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:506b1f29-bc38-4c53-a995-bcbe9d859d60","http://resolver.tudelft.nl/uuid:506b1f29-bc38-4c53-a995-bcbe9d859d60","Effects of Displayed Error Scaling in Compensatory Roll-Axis Tracking Tasks","Breur, S.W.; Pool, D.M.; Van Paassen, M.M.; Mulder, M.","","2010","This paper describes an investigation into the effects of displayed error scaling on manual control behavior during compensatory roll-axis tracking. Previous experiments have indicated that for compensatory displays that, similar to an artificial horizon, present the roll tracking errors in rotational form, the deviations for typical quasi-random forcing function signals are comparatively small and difficult to perceive. This was found to lead to degraded tracking performance and lower crossover frequencies than would be expected. To investigate this, a roll-axis tracking experiment has been performed in which the scaling of the presented tracking errors was varied from 0.5 to 5 times the true tracking error. In addition, both double integrator dynamics and typical conventional roll dynamics of a small jet aircraft were considered in a mixed experimental design. The main hypothesis for this experiment was that increased scaling of the presented roll-axis tracking error would result in improved tracking performance and correlation of manual control inputs with the target forcing function signal. In addition, these effects were hypothesized to be more pronounced for the more difficult double integrator dynamics. For both controlled elements, both tracking performance and linearity of pilot control were indeed found to increase with increasing display gain, leveling of for the highest considered display gains. Further analysis of manual control behavior using McRuer et al.’s Precision Model revealed marked changes in the adopted control strategy due to changes in displayed error scaling, which were found to be highly similar for both controlled elements.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:86dc5507-e4a2-4efb-8ace-7926a0b75812","http://resolver.tudelft.nl/uuid:86dc5507-e4a2-4efb-8ace-7926a0b75812","Perception of Combined Visual and Inertial Low-Frequency Yaw Motion","Valente Pais, A.R.; Van Paassen, M.M.; Mulder, M.; Wentink, M.","","2010","Following a previous study in the Simona simulator on perception of coherent visual and inertial cues in a flight simulator, an experiment is performed in the Desdemona simulator to investigate the influence of the frequency of visual and inertial stimuli on the limits of the perceived coherence zone. The coherence zone is defined as the range of inertial motion amplitudes that, though not being a physical match to the visual cues, are still perceived by subjects as coherent. The main hypothesis tested is that the semi-circular canals dynamics influence the internal comparison between the visually and inertially perceived self-velocity. Furthermore, the results between the Simona and Desdemona studies are compared. In general, the effect of amplitude and frequency on the measured coherence zones follow the same trends as in the previous study: the coherence zone width increases with increasing visual cue amplitude and the point of mean coherence decreases with respect to the one-to-one line for the higher amplitudes. The results for the low frequency and low amplitude stimulus might be affected by the inertial sensory threshold, making it difficult to draw definite conclusions about the posed hypothesis. The results between the two simulator studies are different in terms of absolute values, but the trends are the same.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:0cb1a6a5-3add-40b8-8ae5-9e6ba95f649c","http://resolver.tudelft.nl/uuid:0cb1a6a5-3add-40b8-8ae5-9e6ba95f649c","Analysis of Air Traffic Controller Workload Reduction Based on the Solution Space for the Merging Task","Mercado Velasco, G.A.; Mulder, M.; Van Paassen, M.M.","","2010","Air traffic controller workload is considered to be an important limiting factor to the growth of air traffic. The difficulty of an air traffic control task can be analyzed through examining the problem’s solution space, that is, all possible vector commands that satisfy the constraints of safety, productivity and efficiency. But apart from deriving metrics for workload, a visualization based on the solution space, resulting in the Solution Space Diagram, could help the controller inmanaging the air traffic. An experiment was conducted in which two different levels of traffic density were tested in order to evaluate the effects of presenting the Solution Space Diagram on controller workload. The experiment entailed the task of merging aircraft into a single route and subjects provided subjective ratings of workload at fixed intervals of time. Depending on traffic level and subject experience, significant effects of the Solution Space Diagram were found on the reduction of controller workload.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:b642024a-2298-4f4a-989c-3b827412bc1a","http://resolver.tudelft.nl/uuid:b642024a-2298-4f4a-989c-3b827412bc1a","Tuning of the lateral specific force gain based on human motion perception in the Desdemona simulator","Correia Gracio, B.J.; Van Paassen, M.M.; Mulder, M.; Wentink, M.","","2010","Generally, motion simulators present motion and visual cues different from each other due to the physical limitations of the motion platform. Nonetheless, high fidelity motion platforms are capable of simulating some maneuvers one-to-one, i.e., motion cues equal to visual cues. However, one-to-one simulation is normally not preferred by subjects and the simulator motion is reported as too strong. In this study we investigated whether this overestimation depends on the frequency and amplitude of inertial motion. The stimuli in this study consisted of translations in the lateral direction. The Desdemona research simulator was used to generate the motion profiles. Six sinusoidal profiles with different combinations of amplitude and frequency were used as reference stimuli. For every experimental condition, the visual and inertial information had equal frequency but different amplitude. Subjects had to change the inertial motion amplitude until they obtained the best relation between the two sources of motion information. Our results showed that stimuli with high amplitude were associated with smaller motion gains than stimuli with lower amplitude. The same occurred for stimuli with higher frequency when compared to stimuli with lower frequency. The findings in this study suggest that a dynamic scaling algorithm for inertial motion could improve the perceived realism of motion simulation.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:b7098aac-56a4-4fb6-a983-a66732093d60","http://resolver.tudelft.nl/uuid:b7098aac-56a4-4fb6-a983-a66732093d60","Investigation of Practical Flight Envelope Protection Systems for Small Aircraft","Falkena, W.; Borst, C.; Mulder, J.A.","","2010","Personal air transportation utilizing small aircraft is a market that is expected to grow significantly in the future. For this segment, “stick and rudder” related accidents should be mitigated to guide this process in a safe manner. Instead of downscaling advanced and expensive fly-by-wire platforms that incorporate flight envelope protection found in commercial aircraft, a low cost solution should be considered. This paper focuses on a flight envelope protection system for small aircraft, to allow carefree maneuvering for the less experienced pilot. Preliminary results are obtained from an empirical comparison study in the time domain, between a PID based control limiting approach, a command limiting approach and a constrained Flight Control Law (FCL) approach using Model-based Predictive Control (MPC), with and without parametric model uncertainties. Investigation of the results reveals that, for this study, command limiting and MPC should be preferred over control limiting and that the practicality of command limiting outweighs the small performance increase of MPC.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:3db971d6-22bb-4991-ac92-49c980afb44c","http://resolver.tudelft.nl/uuid:3db971d6-22bb-4991-ac92-49c980afb44c","Modeling Human Dynamics in Combined Ramp-Following and Disturbance-Rejection Tasks","Pool, D.M.; Van Paassen, M.M.; Mulder, M.","","2010","This paper investigates the modeling of humanmanual control behavior for pursuit tracking tasks in which target forcing functions consisting of multiple ramp-like changes in target attitude are used. Due to the use of a pursuit display and the predictability of such forcing function signals, it can be anticipated that a pursuit or precognitive control strategy, consisting of open-loop feedforward control inputs in response to the predictable reference signal, is applied by the human operator. If combined with an additional disturbance on the controlled element, a control task results that is similar to performing a commanded turn entry/exit or altitude capture in turbulence. It is as of yet uncertain if such pursuit or precognitive control is indeed used during such a control task, and to what extent a quasi-random disturbance would suppress pursuit/precognitive control strategies. A human-in-the-loop evaluation of the combined ramp-following and disturbance-rejection task was performed to gather data for the modeling of human manual control behavior. It is found that despite the anticipated pursuit and precognitive control inputs, classical compensatory models of human manual control dynamics are highly capable of describing human dynamics for these specific control tasks. Measured control inputs, however, are found to correspond well with proposed models for open-loop feedforward operations as well, suggesting future evaluation of a model of human behavior that combines, or switches between, error-reducing compensatory and open-loop feedforward operations.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:2463ebfa-0fc9-4eb4-aaf7-8d9368535c83","http://resolver.tudelft.nl/uuid:2463ebfa-0fc9-4eb4-aaf7-8d9368535c83","Optic Flow Based State Estimation for an Indoor Micro Air Vehicle","Verveld, M.J.; Chu, Q.P.; De Wagter, C.; Mulder, J.A.","","2010","This work addresses the problem of indoor state estimation for autonomous flying vehicles with an optic flow approach. The paper discusses a sensor configuration using six optic flow sensors of the computer mouse type augmented by a three-axis accelerometer to estimate velocity, rotation, attitude and viewing distances. It is shown that the problem is locally observable for a moving vehicle. A Kalman filter is used to extract these states from the sensor data. The resulting approach is tested in a simulation environment evaluating the performance of three Kalman filter algorithms under various noise conditions. Finally, a prototype of the sensor hardware has been built and tested in a laboratory setup.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:12f1b18f-7d16-4049-8eae-b707337e8e7e","http://resolver.tudelft.nl/uuid:12f1b18f-7d16-4049-8eae-b707337e8e7e","Towards Integrating Traffic and Terrain Constraints into a Vertical Situation Display","Rijneveld, P.; Borst, C.; Mulder, M.; Van Paassen, M.M.","","2010","Future airspace operations will allow flight crews to plan and fly their own preferred route and time of arrival without much intervention from air traffic control. This implies that pilots become more responsible for planning their own route while maintaining safe separation. This requires a strategic planning tool that support a high level of pilot Situation Awareness. Current aircraft are already equipped with terrain and traffic warning systems to, but these systems only provide short-term conflict resolutions. Recent studies have shown that a constraint-based approach to interface design could be used to support long- and medium-term decision-making and to provide a deeper understanding of the work domain. However, these studies were focused on either terrain or traffic. This paper aims to integrate both by showing the performance, traffic and terrain overlays on an experimental Vertical Situation Display. In a simulator evaluation, in which twelve professional airline pilots participated, this Vertical Situation Display was compared to a baseline Vertical Situation Display that only showed a terrain overlay and intruder aircraft relative to own ship. The experiment results revealed that the performance, traffic and terrain overlays improved pilots’ overall situation awareness and pilots rated their workload lower. Regarding decision-making, however, the results were not significantly better. Regarding safety, there were less traffic conflicts, but more ground proximity intrusions.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:1e456421-197e-4fef-8528-bed022ea4a41","http://resolver.tudelft.nl/uuid:1e456421-197e-4fef-8528-bed022ea4a41","Piloted Simulator Evaluation Results of New Fault-Tolerant Flight Control Algorithm","Lombaerts, T.J.J.; Smaili, M.H.; Stroosma, O.; Chu, Q.P.; Mulder, J.A.; Joosten, D.A.","","2010","A high fidelity aircraft simulation model, reconstructed using the Digital Flight Data Recorder (DFDR) of the 1992 Amsterdam Bijlmermeer aircraft accident (Flight 1862), has been used to evaluate a new Fault-Tolerant Flight Control Algorithm in an online piloted evaluation. This paper focuses on the piloted simulator evaluation results. Reconfiguring control is implemented by making use of Adaptive Nonlinear Dynamic Inversion (ANDI) for manual fly by wire control. After discussing the modular adaptive controller setup, the experiment is described for a piloted simulator evaluation of this innovative recon- figurable control algorithm applied to a damaged civil transport aircraft. The evaluation scenario, measurements and experimental design, as well as the real-time implementation are described. Finally, reconfiguration test results are shown for damaged aircraft models including component as well as structural failures. The evaluation shows that the FTFC algorithm is able to restore conventional control strategies after the aircraft configuration has changed dramatically due to these severe failures. The algorithm supports the pilot after a failure by lowering workload and allowing a safe return to the airport. For most failures, the handling qualities are shown to degrade less with a failure than the baseline classical control system does.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:e7d6e39f-a238-4c46-bd98-b40b9183b59c","http://resolver.tudelft.nl/uuid:e7d6e39f-a238-4c46-bd98-b40b9183b59c","Investigation of Energy Management during Approach: Evaluating the Total Energy-Based Perspective Flight-Path Display","Van den Hoven, M.C.L.; De Jong, P.M.A.; Borst, C.; Mulder, M.; Van Paassen, M.M.","","2010","This paper covers an analysis of the energy management task during the approach phase as well as the design of an experiment supporting this analysis. The energy management task is analyzed using the concept of energy rate demand, which expresses the amount of total energy to be lost in comparison to the minimal energy rate the aircraft can attain at the current speed and configuration. Energy rate demand is explicitly defined by the altitude and speed profile and indicates the demand put on the aircraft by the approach trajectory. A number of approach trajectories are analyzed including a conventional approach, a Continuous Descent Approach (CDA) and a new, experimental, Constant Energy Rate Demand Approach (CERDA). An experiment has been carried out using a total energy-based perspective flight-path display. The results are used to assess the benefits of adding energy information to a tunnel-in-the-sky display and to gain more insight into the energy management task by comparing the different types of energy management as well as energy rate demand with workload and performance. The hypothesis that adding energy information to a baseline tunnel-in-the-sky display will increase the pilot’s energy awareness is supported, however, the hypothesis that the workload would decrease with the energy display has been rejected. No relation could be found between energy rate demand, workload, and performance, rejecting the hypothesis that the performance would decrease and the workload increase with increasing energy rate demand.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:2f4a2faf-2dc3-42f4-a0e2-da0a988e1ddc","http://resolver.tudelft.nl/uuid:2f4a2faf-2dc3-42f4-a0e2-da0a988e1ddc","Identification of the Feedback Component of the Neuromuscular System in a Pitch Control Task","Damveld, H.J.; Abbink, D.A.; Mulder, M.; Mulder, Mark; Van Paassen, M.M.; Van der Helm, F.C.T.; Hosman, R.J.A.W.","","2010","This goal of this study is to understand which parts of the the neuromuscular system contribute during a pitch control task. A novel method developed at the Delft University of Technology allows us to determine the contribution of the neuromuscular feedback system by identifying the admittance, which is the frequency response function of the yielded displacement due to an external force perturbation which applied to control inceptor. In an experiment in a full-motion flight simulator, the neuromuscular admittance was identified during a longitudinal pitch tracking task with a side stick, for two different side stick configurations, an approach configuration with a relatively low stick stiffness, and a cruise configuration with a high stiffness. Besides the admittance, also the muscle activity of eleven muscles was measured. To validate whether the external force perturbation changed the control behavior of the pilot, the visual and vestibular response functions were identified as well. From the measured results it could be concluded that the variations of the control inceptor settings had a significant effect on the neuromuscular feedback system (admittance), although the overall lumped neuromuscular system did not change significantly. A very interesting finding were the very high levels of co-contraction measured during the pitch tracking tasks. And lastly it could be concluded that the required external force perturbation did not affect the control behavior.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:ba549e3d-6b06-4b52-b37c-5d3259ae5d70","http://resolver.tudelft.nl/uuid:ba549e3d-6b06-4b52-b37c-5d3259ae5d70","Immersion and Invariance Based Nonlinear Adaptive Flight Control","Sonneveldt, L.; Van Oort, E.R.; Chu, Q.P.; Mulder, J.A.","","2010","In this paper a theoretical framework for nonlinear adaptive flight control is developed and applied to a simplified, over-actuated nonlinear fighter aircraft model. The framework is based on a modular adaptive backstepping scheme with a new type of nonlinear estimator. The nonlinear estimator is constructed using an invariant manifold based approach which allows for prescribed dynamics to be assigned to the estimation error. Attractivity of the manifold is ensured with the addition of dynamic scaling factors and output filters to the design procedure. The properties of the estimator can be exploited by designing a command filtered backstepping control law that renders the closed-loop system input-to-state stable with respect to the parameter estimation error. It is demonstrated that the resulting modular adaptive controller is easier to tune compared to controllers obtained using the classical adaptive backstepping approaches. Furthermore, the performance of the adaptive controller does not suffer from unpredictable dynamical behavior of the parameter update laws. This is illustrated in numerical simulations where several types of realistic failures are introduced in the aircraft model.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:ef521625-a562-49e9-9bde-44538ce159fe","http://resolver.tudelft.nl/uuid:ef521625-a562-49e9-9bde-44538ce159fe","Full Envelope Modular Adaptive Control of a Fighter Aircraft using Orthogonal Least Squares","Van Oort, E.R.; Sonneveldt, L.; Chu, Q.P.; Mulder, J.A.","","2010","A new adaptive nonlinear flight controller is designed for a high fidelity, six degrees of freedom F-16 model for the entire flight envelope. The design is based on a modular approach which separates the design of the control law and the online identifier. The control law design is based on backstepping with nonlinear damping terms to robustify the design against parameter estimation errors and unknown bounded disturbances. The flight envelope is partitioned into hyperboxes, for each hyperbox a locally valid incremental model is estimated based on the linearized equations of motion. A continuous-time formulation of orthogonal least squares is used for identification of these locally valid models. The obtained local models are interpolated by means of B-splines to obtain a smooth model valid for the complete flight envelope. The performance of the resulting nonlinear adaptive control design is evaluated on the F-16 aircraft model for representative flight conditions, maneuvers, and failure cases.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:1f47e072-ce98-4479-9176-bff9d1bbdfdb","http://resolver.tudelft.nl/uuid:1f47e072-ce98-4479-9176-bff9d1bbdfdb","Development of a Time-Space Diagram to Assist Air Traffic Controllers in Monitoring Continuous Descent Approaches","Mulder, M.; Van Paassen, M.M.; Tielrooij, M.; In 't Veld, A.C.","","2010","","OA-publication; Open Access Fonds","en","book chapter","SCIYO","","","","","","","","Aerospace Engineering","Control & Simulation Division","","","",""
"uuid:33cebd11-ecb7-45d5-8989-fa9e1dfab341","http://resolver.tudelft.nl/uuid:33cebd11-ecb7-45d5-8989-fa9e1dfab341","Time-based Spaced Continuous Descent Approaches in Busy Terminal Manoeuvring Areas","Mulder, M.; Van Paassen, M.M.; De Gelder, N.; Meijer, L.K.","","2010","","Open Access Publication","en","book chapter","SCIYO","","","","","","","","Aerospace Engineering","Control & Simulation","","","",""
"uuid:cf26cacb-15c8-4fb2-9ea8-ed6c84c3372e","http://resolver.tudelft.nl/uuid:cf26cacb-15c8-4fb2-9ea8-ed6c84c3372e","A correlation-based misfit criterion for wave-equation traveltime tomography","Van Leeuwen, T.; Mulder, W.A.","","2010","Wave-equation traveltime tomography tries to obtain a subsurface velocity model from seismic data, either passive or active, that explains their traveltimes. A key step is the extraction of traveltime differences, or relative phase shifts, between observed and modelled finite-frequency waveforms. A standard approach involves a correlation of the observed and measured waveforms. When the amplitude spectra of the waveforms are identical, the maximum of the correlation is indicative of the relative phase shift. When the amplitude spectra are not identical, however, this argument is no longer valid. We propose an alternative criterion to measure the relative phase shift. This misfit criterion is a weighted norm of the correlation and is less sensitive to differences in the amplitude spectra. For practical application it is important to use a sensitivity kernel that is consistent with the way the misfit is measured. We derive this sensitivity kernel and show how it differs from the standard banana–doughnut sensitivity kernel. We illustrate the approach on a cross-well data set.","Body waves; Seismic tomography; Inverse theory; OA-Fund TU Delft","en","journal article","John Wiley & Sons","","","","","","","","Civil Engineering and Geosciences","Applied Geophysics and Petrophysics","","","",""
"uuid:1760ca21-5d3b-48eb-9bea-5ef717f50822","http://resolver.tudelft.nl/uuid:1760ca21-5d3b-48eb-9bea-5ef717f50822","Development of an innovative single scull for the recreational rower","Voogd-Claessen, H.; Van Bladel, C.; Van Daalen, T.; Dekkers, B.; Elwick, R.; Mulder, F.; Nachmany, G.","","2010","Rowing is a sport which requires a proper technique, strong core balance, physical strength and endurance. Rowing boats designed for competition are built of epoxy laminate with glass or carbon reinforcement; they are lightweight, stiff, long, and narrow to achieve minimal water resistance. However, this makes them extremely unstable and difficult to handle for less experienced rowers. Current boats designed for recreational users are generally made of polyethylene; they are more stable, heavier, but are difficult to handle individually and generally do not provide the same ‘rowing experience’ that users desire. To bridge this gap an innovative recreational single scull rowing boat has been designed and built as prototype. Focus for the design was the hydrodynamics of the hull, use of light weight materials and incorporation of subsystems for better performance. A design for a better stability mainly depends on a combination of the width of the hull, the shape of the cut section of the hull and the displacement of the mass. An important aspect of the change in stability is the resistance of the boat; all changes to the existing shape of the fast competition hull are likely to result an increase in resistance. Therefore a number of existing and new hull shapes were modelled and hydrodynamic properties were analysed in order to achieve a design with optimal balance in speed and stability. With the programme DELFTship TM the frictional resistances of the hull models were calculated at different speeds. To increase the stiffness and to save weight attention was paid to the choice of materials and construction method, taking into account the requirement of affordability for private ownership. With the implementation of sliding riggers an increase in speed can be attained due to the increased power. Also stability is increased due to elimination of pitching from weight transfer in the boat. The new boat design incorporates the sliding rigger system; this had a huge effect on the other subsystems of the boat and on the design (mainly the length) of the hull. This paper reports the development from a perspective of ‘embodiment design’ to achieve the required performance. Analyses of hydrodynamics, materials and production technique and section of subsystems finally resulted in the design of rowing boat with a completely new hull shape, matching the requirements of stability and speed. A first prototype of the innovative single scull rowing boat for the recreational user was built. User tests have shown that this boat provides the stability of current recreational boats, with the addition of a good ‘rowing experience,’ and faster feeling of competition boats.","rowing; product design; embodiment design; hydrodynamics; composite materials","en","journal article","Elsevier","","","","","","","","Industrial Design Engineering","","","","",""
"uuid:7cc0122c-03b8-4a35-a3ce-f2937b312396","http://resolver.tudelft.nl/uuid:7cc0122c-03b8-4a35-a3ce-f2937b312396","Haptic feedback; making safety boundaries tangible","Mulder, M.","","2010","","","en","journal article","Society for Aerospace Engineering Students VSV Leonardo da Vinci","","","","","","","","Aerospace Engineering","","","","",""
"uuid:a8904771-a428-4460-9c7f-2fcc98713823","http://resolver.tudelft.nl/uuid:a8904771-a428-4460-9c7f-2fcc98713823","An analysis of braking measures","De Groot, S.; De Winter, J.C.F.; Wieringa, P.A.; Mulder, M.","","2010","Braking to a full stop at a prescribed target position is a driving manoeuvre regularly used in experiments to investigate driving behaviour or to test vehicle acceleration feedback systems in simulators. Many different performance measures have been reported in the literature for analysing braking. These may or may not be useful to analyse the stopping manoeuvre, because a number of potential problems exist: 1) the scores on a measure may be insufficiently reliable, 2) the measure may be invalid, or 3) the measure may be strongly intercorrelated. A simulation and empirical study were conducted to analyse various measures. From the simulation study it was concluded that 1) An R2 measure based on the speed vs time relationship can be used to measure deviations from a constant deceleration, 2) minimum time-to-collision is sensitive to target position offsets, and 3) mean TTC-dot can capture braking behaviour characteristics but the required definition of a begin and end sample-point for its calculation is a disadvantage. The empirical study calculated a set of measures using data of 60 participants driving a simulation-based session of 10 stops. It is concluded that reliable and valid measures for a braking experiment are provided by the speed and distance to the target position at braking onset, the stopping position with respect to the target and the R2 measure to measure deviations from a constant deceleration. Recommended additional measures are: The mean speed of the complete braking manoeuvre, stopping position consistency, maximum deceleration and onset jerk.","","en","conference paper","","","","","","","","","Mechanical, Maritime and Materials Engineering","BioMechanical Engineering","","","",""
"uuid:a446a509-c221-41ad-94b0-1afe3aafc4d9","http://resolver.tudelft.nl/uuid:a446a509-c221-41ad-94b0-1afe3aafc4d9","System provided with an assistance-controller for assisting an operator of the system, control-operation assisting device, control-operation assisting method, driving-operation assisting device, and driving-operation assisting method","Mulder, M.; Abbink, D.; Van Paassen, R.; Mulder, M.; Van der Helm, F.; Boer, E.R.; Takada, Y.","","2010","A target-travel-path generating circuit calculates a target travel path along which the controlled object can travel in the future from the current controlled object position, an ideal-control-signal calculating circuit calculates a control profile S to travel along the target travel path P, and a difference calculating circuit calculates a difference d between the ideal control magnitude S and a current control magnitude S. An operation system assistance controller controls the operation system based on the magnitude of the calculated difference d to assist the control operation of the operator, the control-operation-state of the operator, the environment-state, and the required operation-precision. Accordingly, it is possible to provide the operator with control operation assistance that is a function of the magnitude of the difference d from an ideal control state, the control-operation-state of the operator, the environment-state, and the required operation-precision, and thus, a control-operation assistance control can be outputted that is suitable for the conditions that characterize the state of the operator, the environment, and the controlled object.","","en","patent","European Patent Office","","","","","","","","Mechanical, Maritime and Materials Engineering","Biomechanical Engineering","","","",""
"uuid:4e038105-a11a-46f4-8079-35b3b115aaba","http://resolver.tudelft.nl/uuid:4e038105-a11a-46f4-8079-35b3b115aaba","Lithium Storage in Amorphous TiO2 Nanoparticles","Borghols, W.J.H.; Lützenkirchen-Hecht, D.; Haake, U.; Chan, W.; Lafont, U.; Kelder, E.M.; Van Eck, E.R.H.; Kentgens, A.P.M.; Mulder, F.M.; Wagemaker, M.","","2010","Amorphous titanium oxide nanoparticles were prepared from titanium isopropoxide. In situ measurements reveal an extraordinary high capacity of 810 mAh/g on the first discharge. Upon cycling at a charge/discharge rate of 33.5 mA/g, this capacity gradually decreases to 200 mAh/g after 50 cycles. The origin of this fading was investigated using X-ray absorption spectroscopy and solid-state nuclear magnetic resonance. These measurements reveal that a large fraction of the total amount of the consumed Li atoms is due to the reaction of H2O/OH species adsorbed at the surface to Li2O, explaining the irreversible capacity loss. The reversible capacity of the bulk, leading to the Li0.5TiO2 composition, does not explain the relatively large reversible capacity, implying that part of Li2O at the TiO2 surface may be reversible. The high reversible capacity, also at large (dis)charge rates up to 3.35 A/g (10C), makes this amorphous titanium oxide material suitable as a low cost electrode material in a high power battery.","nanoparticles; NMR spectroscopy; secondary cells; titanium compounds; X-ray absorption spectra","en","journal article","The Electrochemical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:164d8e28-76a7-4459-b6a8-1ca298296720","http://resolver.tudelft.nl/uuid:164d8e28-76a7-4459-b6a8-1ca298296720","Neuromuscular Analysis as a Guideline in designing Shared Control","Abbink, D.A.; Mulder, M.","","2010","","","en","book chapter","InTech","","","","","","","","Mechanical, Maritime and Materials Engineering","BioMechanical Engineering","","","",""
"uuid:950355c2-0022-4e20-979c-ed527f8af5f3","http://resolver.tudelft.nl/uuid:950355c2-0022-4e20-979c-ed527f8af5f3","A comparison of seismic velocity inversion methods for layered acoustics","Van Leeuwen, T.; Mulder, W.A.","","2009","In seismic imaging, one tries to infer the medium properties of the subsurface from seismic reflection data. These data are the result of an active source experiment, where an explosive source and an array of receivers are placed at the surface. Due to the absence of low frequencies in the data, the corresponding inverse problem is strongly non-linear in the slowly varying component of the velocity. The least-squares misfit functional typically exhibits local minima and has a small basin of attraction. The usual approach of fitting the data in a least-squares sense by employing a gradient-based optimisation method will therefore most likely result in a wrong velocity model. In the geophysical community, this problem has long been recognised and alternative formulations of the inverse problem have been developed. We review several of these formulations and analyse the sensitivity to the error in the smooth velocity component. This analysis is carried out for laterally homogeneous velocities using an asymptotic solution of the wave equation. The analysis suggests that formulations which are geared towards fitting the phases of the data, rather than the amplitudes, have smooth corresponding misfit functionals with a large basin of attraction.","","en","journal article","Institute of Physics","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:4f9f2aa0-8d2f-4eb7-ace8-a839b83aff59","http://resolver.tudelft.nl/uuid:4f9f2aa0-8d2f-4eb7-ace8-a839b83aff59","Aerospace human-machine systems: From safety to where?","Mulder, M.","","2009","","Intreerede","en","public lecture","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:41c88d0a-dba3-464f-a8e7-fddab190712a","http://resolver.tudelft.nl/uuid:41c88d0a-dba3-464f-a8e7-fddab190712a","Hybrid Container Cranes: An Energy Management Strategy","Mulder, S.","","2009","","","en","journal article","Delft University of Technology","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:44330aea-77b9-46ad-b2ab-09452b766420","http://resolver.tudelft.nl/uuid:44330aea-77b9-46ad-b2ab-09452b766420","Artificial Force Field for Haptic Feedback in UAV Teleoperation","Lam, T.M.; Boschloo, H.W.; Mulder, M.; Van Paassen, M.M.","","2009","The feedback upon which operators in teleoperation tasks base their control actions differs substantially from the feedback to the driver of a vehicle. On the one hand, there is often a lack of sensory information; on the other hand, there is additional status information presented via the visual channel. Haptic feedback could be used to unload the visual channel and to compensate for the lack of feedback in other modalities. For collision avoidance, haptic feedback could provide repulsive forces via the control inceptor. Haptic feedback allows operators to interpret the repulsive forces as impedance to their control deflections when a potential for collision exists. Haptic information can be generated from an artificial force field (AFF) that maps environment constraints to repulsive forces. This paper describes the design and theoretical evaluation of a novel AFF, i.e., the parametric risk field, for teleoperation of an uninhabited aerial vehicle (UAV). The field allows adjustments of the size, shape, and force gradient by means of parameter settings, which determine the sensitivity of the field. Computer simulations were conducted to evaluate the effectiveness of the field for collision avoidance for various parameter settings. Results indicate that the novel AFF more effectively performs the collision avoidance function than potential fields known from literature. Because of its smaller size, the field yields lower repulsive forces, results in less force cancellation effects, and allows for larger UAV velocities. This indicates less operator control demand and more effective UAV operations, both expected to lead to lower operator workload, while, at the same time, increasing safety.","artificial force field (AFF); collision avoidance; haptic feedback; teleoperation; uninhabited aerial vehicle (UAV)","en","journal article","IEEE","","","","","","","","Aerospace Engineering","Control and Operations","","","",""
"uuid:f2b6bdbd-5d11-4ec5-ac7e-d2c2ce21144c","http://resolver.tudelft.nl/uuid:f2b6bdbd-5d11-4ec5-ac7e-d2c2ce21144c","A new approach to linear regression with multivariate splines","De Visser, C.C.; Chu, Q.P.; Mulder, J.A.","","2009","A new methodology for creating highly accurate, static nonlinear maps from scattered, multivariate data is presented. This new methodology uses the B-form polynomials of multivariate simplex splines in a new linear regression scheme. This allows the use of standard parameter estimation techniques for estimating the B-coefficients of the multivariate simplex splines. We present a generalized least squares estimator for the B-coefficients, and show how the estimated B-coefficient variances lead to a new model quality assessment measure in the form of the B-coefficient variance surface. The new modeling methodology is demonstrated on a nonlinear scattered bivariate dataset.","splines; parameter estimation; scattered data; multivariate splines","en","journal article","Elsevier","","","","","","","2014-05-01","Aerospace Engineering","Control & Operations","","","",""
"uuid:44451e6a-fc1f-4eeb-8183-cc25af951919","http://resolver.tudelft.nl/uuid:44451e6a-fc1f-4eeb-8183-cc25af951919","Size Effects in Li4+xTi5O12 Spinel","Borghols, W.J.H.; Wagemaker, M.; Lafont, U.; Kelder, E.M.; Mulder, F.M.","","2009","","Li-ion battery; neutron diffraction; nanosizing","en","journal article","The Electrochemical Society","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:1ff687eb-a484-40fb-8ade-9dd0c6e83f4b","http://resolver.tudelft.nl/uuid:1ff687eb-a484-40fb-8ade-9dd0c6e83f4b","Neutron Depth Profiling for In Situ Lithium Analyses in All-solid-state Thin-film Microbatteries","Oudenhoven, J.; Labohm, F.; Niessen, R.; Mulder, F.; Notten, P.","","2009","","","en","journal article","The Electrochemical Society","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:965e0e5c-3297-4c96-be4d-d254c403a852","http://resolver.tudelft.nl/uuid:965e0e5c-3297-4c96-be4d-d254c403a852","Designing with Care: The Future of Pervasive Healthcare","Mulder, I.; Schikhof, Y.; Vastenburg, M.H.; Card, A.; Dunn, T.; Komninos, A.; McGee-Lennon, M.; Santcroos, M.; Tiotto, G.; Van Gils, M.; Van 't Klooster, J.W.; Veys, A.; Zarifi Eslami, M.","","2009","","","en","journal article","IEEE","","","","","","","","Industrial Design Engineering","Industrial Design","","","",""
"uuid:32a1cf88-aebc-4cc9-85b7-0870380ca7d5","http://resolver.tudelft.nl/uuid:32a1cf88-aebc-4cc9-85b7-0870380ca7d5","An ambiguity in attenuation scattering imaging","Mulder, W.A.; Hak, B.","","2009","","inverse theory; seismic attenuation; wave scattering and diffraction","en","journal article","Royal Astronomical Society","","","","","","","2010-02-03","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:8f825342-0860-4316-a3d1-66b375cce610","http://resolver.tudelft.nl/uuid:8f825342-0860-4316-a3d1-66b375cce610","Modeling Human Multimodal Perception and Control Using Genetic Maximum Likelihood Estimation","Zaal, P.M.T.; Pool, D.M.; Chu, Q.P.; Van Paassen, M.M.; Mulder, M.; Mulder, J.A.","","2009","This paper presents a new method for estimating the parameters of multi-channel pilot models that is based on maximum likelihood estimation. To cope with the inherent nonlinearity of this optimization problem, the gradient-based Gauss-Newton algorithm commonly used to optimize the likelihood function in terms of output error is complemented with a genetic algorithm. This significantly increases the probability of finding the global optimum of the optimization problem. The genetic maximum likelihood method is successfully applied to data from a recent human-in-the-loop experiment. Accurate estimates of the pilot model parameters and the remnant characteristics were obtained. Multiple simulations with increasing levels of pilot remnant were performed, using the set of parameters found from the experimental data, to investigate how the accuracy of the parameter estimate is affected by increasing remnant. It is shown that only for very high levels of pilot remnant the bias in the parameter estimates is substantial. Some adjustments to the maximum likelihood method are proposed to reduce this bias.","System Identification; Pilot Modeling; Parameter Estimation","en","journal article","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:b0e41aea-7004-4677-b050-14f066d95450","http://resolver.tudelft.nl/uuid:b0e41aea-7004-4677-b050-14f066d95450","Heat in the city - an inventory of knowledge and knowledge deficiencies regarding heat stress in Dutch cities and options for its mitigation.","Salcedo Rahola, T.B.; Van Oppen, P.; Mulder, K.","","2009","This report gives an overview of heat stress problems in urban areas of the Netherlands and various options for mitigating this stress. Climate change is causing more occurrences of heat waves. Urban areas in particular will suffer the most, as they are warmer than the countryside. * What is known about the magnitude of heat stress in Dutch urban areas? * What are the consequences? * What research is needed to clarify its effects? * Which options in particular could do with further study in order to prevent fatalities, maintain comfort levels and avoid increases in energy consumption for summer cooling? This report aims at identifying: * the foreseeable problems of urban heat in the Netherlands; * the specifics (geographic, cultural, economic, technological) that apply to the Netherlands; * the most promising options for mitigating urban heat; and * the priorities for further research.","Urban Heat Island; Heat Stress; Adaptation; Climate Change","en","report","Klimaat voor Ruimte","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:b0d2cc9f-c6b9-49b0-91e5-d5ef37e32ecb","http://resolver.tudelft.nl/uuid:b0d2cc9f-c6b9-49b0-91e5-d5ef37e32ecb","Neural Network Output Optimization Using Interval Analysis","De Weerdt, E.; Chu, Q.P.; Mulder, J.A.","","2009","The problem of output optimization within a specified input space of neural networks (NNs) with fixed weights is discussed in this paper. The problem is (highly) nonlinear when nonlinear activation functions are used. This global optimization problem is encountered in the reinforcement learning (RL) community. Interval analysis is applied to guarantee that all solutions are found to any degree of accuracy with guaranteed bounds. The major drawbacks of interval analysis, i.e., dependency effect and high-computational load, are both present for the problem of NN output optimization. Taylor models (TMs) are introduced to reduce these drawbacks. They have excellent convergence properties for small intervals. However, the dependency effect still remains and is even made worse when evaluating large input domains. As an alternative to TMs, a different form of polynomial inclusion functions, called the polynomial set (PS) method, is introduced. This new method has the property that the bounds on the network output are tighter or at least equal to those obtained through standard interval arithmetic (IA). Experiments show that the PS method outperforms the other methods for the NN output optimization problem.","feedforward neural networks (FFNNs); global optimization; inclusion function; interval analysis; optimization methods; polynomial set; radial basis function neural networks (RBFNNs); taylor expansion; taylor model (TM)","en","journal article","IEEE","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:06991e51-6139-4812-b5aa-12e722aabbc8","http://resolver.tudelft.nl/uuid:06991e51-6139-4812-b5aa-12e722aabbc8","Density functional calculations of potential energy surface and charge transfer integrals in molecular triphenylene derivative HAT6","Zbiri, M.; Johnson, M.R.; Kearley, G.J.; Mulder, F.M.","","2009","We investigate the effect of structural fluctuations on charge transfer integrals, overlap integrals, and site energies in a system of two stacked molecular 2,3,6,7,10,11-hexakishexyloxytriphenylene (HAT6), which is a model system for conducting devices in organic photocell applications. A density functional based computational study is reported. Accurate potential energy surface calculations are carried out using an improved meta-hybrid density functional to determine the most stable configuration of the two weakly bound HAT6 molecules. The equilibrium parameters in terms of the twist angle and co-facial separation are calculated. Adopting the fragment approach within the Kohn–Sham density functional framework, these parameters are combined to a lateral slide, to mimic structural/conformational fluctuations and variations in the columnar phase. The charge transfer and spatial overlap integrals, and site energies, which form the matrix element of the Kohn–Sham Hamiltonian are derived. It is found that these quantities are strongly affected by the conformational variations. The spatial overlap between stacked molecules is found to be of considerable importance since charge transfer integrals obtained using the fragment approach differ significantly from those using the dimer approach.","Organic photocells; Columnar stacked HAT6; Density functional theory; Potential energy surface; Charge transfer integrals","en","journal article","Springer","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:cfe89c67-35a0-420f-8f80-a30cfcdffe84","http://resolver.tudelft.nl/uuid:cfe89c67-35a0-420f-8f80-a30cfcdffe84","What has to be learnt for sustainability? A comparison of bachelor engineering education competences at three European universities","Segalas, J.; Ferrer-Balas, D.; Svanström, M.; Lundqvist, U.; Mulder, K.F.","","2009","In a period of harmonisation of the higher education system in Europe, a question is if also learning about sustainability at the universities is converging and what advantages this may have. This paper is an effort to present and advance the work on describing desired sustainability competences for engineering Bachelor graduates in three technical universities (Chalmers in Sweden, DUT in The Netherlands and UPC-Barcelona in Spain) using the European Higher Education Area (EHEA) descriptors. The paper also sheds light on whether there is conformity or not in desired sustainability competences (or in how sustainable development (SD) competences are handled) at the three universities. For universities outside the EHEA, this paper gives hints on the type of sustainability competences that will be required from their first-cycle graduates should they want to continue with second-cycle studies within the EHEA. The results show that the three universities follow a similar pattern in the classification of the competences (Knowledge and understanding, Skills and abilities, and Attitudes) and that there are minor divergences with respect to the list of competences and the levels of learning that Bachelor students should have when graduating. Definition of competences is an area that needs development, and this paper is part of a learning process for the three universities. This study shows that there is improvement potential for all three universities when it comes to being explicit and exact in the description of the desired SD learning.","Sustainability; Engineering; Education; Competences; Europe","en","journal article","Springer","","","","","","","","Technology, Policy and Management","Values and Technology","","","",""
"uuid:f3746c29-2e89-44b2-a715-45ad732501cd","http://resolver.tudelft.nl/uuid:f3746c29-2e89-44b2-a715-45ad732501cd","Stiffness-force feedback in UAV tele-operation","Lam, T.M.; Mulder, M.; Van Paassen, M.M.","Lam, T.M. (contributor)","2009","","","en","book chapter","In-Tech Education and Publishing","","","","","","","","Aerospace Engineering","Aerospace Design, Integration and Operations","","","",""
"uuid:64479473-1f94-4928-bcd3-e7a3af90af38","http://resolver.tudelft.nl/uuid:64479473-1f94-4928-bcd3-e7a3af90af38","Ecological Interface Design of a Tactical Airborne Separation Assistance Tool","Van Dam, S.; Mulder, M.; Van Paassen, M.M.","","2008","In a free-flight airspace environment, pilots have more freedom to choose user-preferred trajectories. An onboard pilot support system is needed that exploits travel freedom while maintaining spatial separation with other traffic. Ecological interface design is used to design an interface tool that assists pilots with the tactical planning of efficient conflict-free trajectories toward their destination. Desired pilot actions emerge from the visualization of workspace affordances in terms of a suitable description of aircraft (loco)motion. Traditional models and descriptions for aircraft motion cannot be applied efficiently for this purpose. Through functional modeling, more suitable locomotion models for trajectory planning are analyzed. As a result, a novel interface, the state vector envelope, is presented that is intended to provide the pilot with both low-level information, allowing direct action, and high-level information, allowing conflict understanding and situation awareness.","ecological interface design (EID); functional modeling; navigation interface; separation assistance","en","journal article","IEEE","","","","","","","","Aerospace Engineering","Control and Operations","","","",""
"uuid:1b484198-cf85-4350-8c30-6f271e6d9680","http://resolver.tudelft.nl/uuid:1b484198-cf85-4350-8c30-6f271e6d9680","Near-surface attenuation estimation using wave-propagation modeling","El Yadari, N.; Ernst, F.; Mulder, W.","","2008","The effect of the near surface on seismic land data can be so severe that static corrections are insufficient. Full-waveform inversion followed by redatuming may be an alternative, but inversion will work only if the starting model is sufficiently close to the true model. As a first step toward determining a viscoelastic near-surface model, we assume that existing methods can provide a horizontally layered velocity and density model. Because near-surface attenuation is strongest, we propose a method to estimate the P-wave attenuation based on viscoacoustic finite-difference modeling. We compare energy decay along traveltime curves of reflection and refraction events in the modeled and observed seismic data for a range of attenuation parameters. The best match provides an estimate of the attenuation. First, we estimate only the attenuation of the top layer and study the sensitivity to depth and velocity perturbations. Then, we consider multiple layers. We apply the method to synthetic and real data and investigate the effect of source wavelet and topography. The method is robust against depth and velocity perturbations smaller than 10%. The results are sensitive to the source wavelet. Incorporating the surface topography in the computed traveltimes reduces the uncertainty of the attenuation estimates, especially for deeper layers.","finite difference methods; inverse problems; seismic waves; seismology; wavelet transforms","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geotechnology","","","",""
"uuid:98d2d7be-3275-4269-b372-48d2c20f64eb","http://resolver.tudelft.nl/uuid:98d2d7be-3275-4269-b372-48d2c20f64eb","Role Identification of Yaw and Sway Motion in Helicopter Yaw Control Tasks","Ellerbroek, J.; Stroosma, O.; Van Paassen, M.M.; Mulder, M.","","2008","A set of experiments has been conducted to investigate the relative effect of translational and rotational motion cues on pilot performance. Two helicopter yaw control tasks were performed on the SIMONA: a yaw capture task and a target-tracking task with simulated turbulence. The yaw capture task was a repetition of a task performed previously at two different simulator facilities. Shaping filters and added delays were used to match simulator characteristics with the previous experiments. In contrast to previous conclusions, results from the current study show more equal contributions of yaw and sway motion on performance and subjective simulator motion fidelity. Analyses of the different vestibular cues using multiloop pilot models, estimated from measurement data from the target-tracking task, also indicate comparable utilization of the yaw and sway motion cues.","human control behavior","en","journal article","AIAA","","","","","","","","Aerospace Engineering","Control and Operations","","","",""
"uuid:1d56bfde-30de-4b56-bf37-1de50fe95d0c","http://resolver.tudelft.nl/uuid:1d56bfde-30de-4b56-bf37-1de50fe95d0c","Resistivity imaging with controlled-source electromagnetic data: Depth and data weighting","Plessix, R.E.; Mulder, W.A.","","2008","We discuss some computational aspects of resistivity imaging by inversion of offshore controlled-source electromagnetic data. We adopt the classic approach to imaging by formulating it as an inverse problem. A weighted least-squares functional measures the misfit between synthetic and observed data. Its minimization by a quasi-Newton algorithm requires the gradient of the functional with respect to the model parameters. We compute the gradient with the adjoint-state technique. Preconditioners can improve the convergence of the inversion. Diagonal preconditioner based on a Born approximation are commonly used. In the context of CSEM inversion, the Born approximation is not really accurate, this limits the possibility of estimating a correct approximation of the Hessian in a smooth medium or, in fact, in any reference background that does not roughly account for the resistors. We hence rely on the limited memory BFGS approximation of the inverse of the Hessian and we improve the inversion convergence with the help of a heuristic data and depth weighting. Based on a numerical example, we show that a simple exponential depth weighting combined with an offset or frequency data weighting significantly improves the convergence rate of a deep-water controlled-source electromagnetic data inversion.","","en","journal article","Institute of Physics","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:997f4788-e72f-4506-9049-b6b1c3c3c3e5","http://resolver.tudelft.nl/uuid:997f4788-e72f-4506-9049-b6b1c3c3c3e5","Geophysical modelling of 3D electromagnetic diffusion with multigrid","Mulder, W.A.","","2008","The performance of a multigrid solver for time-harmonic electromagnetic problems in geophysical settings was investigated. With the low frequencies used in geophysical surveys for deeper targets, the light-speed waves in the earth can be neglected. Diffusion of induced currents is the dominant physical effect. The governing equations were discretised by the Finite-Integration Technique. The resulting set of discrete equation was solved by a multigrid method. The multigrid method provided excellent convergence with constant grid spacings, but not on stretched grids. The slower convergence rate of the multigrid method could be compensated by using bicgstab2, in which case multigrid acted as a preconditioner. Still, the overall performance was less than satisfactory with substantial grid stretching.","","en","journal article","Springer","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:f1a67f2b-06a1-457d-b2be-c4171c6b489a","http://resolver.tudelft.nl/uuid:f1a67f2b-06a1-457d-b2be-c4171c6b489a","A Two-Dimensional Weighting Function for a Driver Assistance System","De Winter, J.; Mulder, M.; Van Paassen, M.M.; Abbink, D.A.; Wieringa, P.A.","","2008","Driver assistance systems that supply force feedback (FF) on the accelerator commonly use relative distance and velocity with respect to the closest lead vehicle in front of the own vehicle. This 1-D feedback might not accurately represent the situation and can cause unwanted step-shaped changes in the FFs during lateral maneuvers. To address these shortcomings, a 2-D system is proposed that calculates FF using a weighted average of the influences of lead vehicles. Offline simulations and an experiment in a driving simulator were performed to compare no feedback, 1-D systems, and the novel 2-D system during a car-following task with cut-in maneuvers. Results show that the 2-D feedback resulted in lower mean forces, lower response times to cut-in vehicles, and favorable subjective experiences as compared to the 1-D systems.","accelerator; driver assistance; force feedback (FF); weighting function","en","journal article","IEEE","","","","","","","","Mechanical, Maritime and Materials Engineering","Biomechanical Engineering","","","",""
"uuid:f72b15cb-70c7-4bbc-8056-1756adcee55c","http://resolver.tudelft.nl/uuid:f72b15cb-70c7-4bbc-8056-1756adcee55c","A Two-Dimensional Weighting Function for a Driver Assistance System","De Winter, J.C.F.; Mulder, M.; Van Paassen, M.M.; Abbink, D.A.; Wieringa, P.A.","","2008","Driver assistance systems that supply force feedback (FF) on the accelerator commonly use relative distance and velocity with respect to the closest lead vehicle in front of the own vehicle. This 1-D feedback might not accurately represent the situation and can cause unwanted step-shaped changes in the FFs during lateral maneuvers. To address these shortcomings, a 2-D system is proposed that calculates FF using a weighted average of the influences of lead vehicles. Offline simulations and an experiment in a driving simulator were performed to compare no feedback, 1-D systems, and the novel 2-D system during a car-followingtask with cut-in maneuvers. Results show that the 2-D feedback resulted in lower mean forces, lower response times to cut-in vehicles, and favorable subjective experiences as compared to the 1-D systems.","accelerator; driver assistance,; force feedback (FF); weighting function","en","journal article","IEEE","","","","","","","","Mechanical, Maritime and Materials Engineering","Biomechanical Engineering","","","",""
"uuid:24bebec3-b04e-43d0-b852-db6f0f3b53ae","http://resolver.tudelft.nl/uuid:24bebec3-b04e-43d0-b852-db6f0f3b53ae","Feasibility analysis of achieving a stabilized approach","Heiligers, M.M.; Van Holten, T.; Mulder, M.","","2008","","Approach; Stabilized Approach; Pilot; Task Demand Load; RNAV","en","conference paper","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:f71b3260-0311-4b06-b4d2-f8c9123d0e53","http://resolver.tudelft.nl/uuid:f71b3260-0311-4b06-b4d2-f8c9123d0e53","On the reduction of NOx emission levels by performing low NOx flights","Mulder, T.J.; Ruijgrok, G.J.J.","","2008","","","en","conference paper","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:15b145d7-d09e-41a5-ad30-55ba7899e9a8","http://resolver.tudelft.nl/uuid:15b145d7-d09e-41a5-ad30-55ba7899e9a8","Time-domain modeling of electromagnetic diffusion with a frequency-domain code","Mulder, W.A.; Wirianto, M.; Slob, E.C.","","2007","We modeled time-domain EM measurements of induction currents for marine and land applications with a frequency-domain code. An analysis of the computational complexity of a number of numerical methods shows that frequency-domain modeling followed by a Fourier transform is an attractive choice if a sufficiently powerful solver is available. A recently developed, robust multigrid solver meets this requirement. An interpolation criterion determined the automatic selection of frequencies. The skin depth controlled the construction of the computational grid at each frequency. Tests of the method against exact solutions for some simple problems and a realistic marine example demonstrate that a limited number of frequencies suffice to provide time-domain solutions after piecewise-cubic Hermite interpolation and a fast Fourier transform.","Fourier transforms; frequency-domain analysis; terrestrial electricity; time-domain analysis","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geotechnology","","","",""
"uuid:d16d5860-72e6-45e9-9f56-0cfcb41d86ce","http://resolver.tudelft.nl/uuid:d16d5860-72e6-45e9-9f56-0cfcb41d86ce","Retrieval of reflections from seismic background?noise measurements","Draganov, D.S.; Wapenaar, K.; Mulder, W.; Singer, J.; Verdel, A.","","2007","The retrieval of the earth's reflection response from cross?correlations of seismic noise recordings can provide valuable information, which may otherwise not be available due to limited spatial distribution of seismic sources. We cross?correlated ten hours of seismic background?noise data acquired in a desert area. The cross?correlation results show several coherent events, which align very well with reflections from an active survey at the same location. Therefore, we interpret these coherent events as reflections. Retrieving seismic reflections from background?noise measurements has a wide range of applications in regional seismology, frontier exploration and long?term monitoring of processes in the earth's subsurface.","cross-correlation; Green's function retrieval; reflections; interferometry","en","journal article","American Geophysical Union","","","","","","","","Civil Engineering and Geosciences","Geotechnology","","","",""
"uuid:008d10dc-3aa1-4b29-b445-579278543057","http://resolver.tudelft.nl/uuid:008d10dc-3aa1-4b29-b445-579278543057","Haptic gas pedal feedback for active car-following support","Mulder, M.","Mulder, J.A. (promotor); van der Helm, F.C.T. (promotor); Mulder, M. (promotor)","2007","The research presented in this dissertation focuses on supporting drivers in the longitudinal control of their vehicle during car-following. The goal of the research is the human-centred development of a haptic gas pedal interface that comfortably supports drivers in maintaining a safe separation with a leading vehicle during car-following. Two different approaches were found to be suitable for implementation as haptic information providers through the gas pedal. The first approach was to add a force to the gas pedal dynamics which would have to be related to the safe-field-of-travel ahead of the own vehicle and changes therein. The gas pedal dynamics, that is, the force/pedal-position relationship is not changed by this approach. The second approach was to change the stiffness of the gas pedal by adding a virtual stiffness to the inherent stiffness of the gas pedal. By doing so, the dynamics of the gas pedal are changed depending on the changes detected in the safe-field-of-travel. In both approaches, an electrical actuator provides the additional force or stiffness. The main hypothesis of this dissertation is the assumption that with the appropriate haptic feedback of longitudinal traffic information drivers will adopt a force-task in controlling the haptic gas pedal. Experimental verification leads to the conclusion that the stiffness feedback design with time-to-contact information scaled by time headway performs best in this respect.","haptic feedback; force; stiffness; gas pedal; car-following; time to contact; ttc; time headway; thw; driver; automotive; driving; driver support; human-centered","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:2fd15bee-2b8b-4efb-a1aa-f19f3c63e393","http://resolver.tudelft.nl/uuid:2fd15bee-2b8b-4efb-a1aa-f19f3c63e393","Micro x-ray source","Kruit, P.; Hagen, C.W.; Mulder, E.H.","","2006","The invention relates 'to a micro X-ray source comprising a target acting as anode, and a cathode, which during operation interacts with the target and functions as electron source, wherein the target is embodied as a metal foil possessing a spot where the electrons from the electron source arrive, the metal foil being locally thinner at the spot.","","en","patent","European Patent Office","","","","","","","","Applied Sciences","","","","",""
"uuid:df65da5c-e43f-47ab-b80d-2f8ee7f35464","http://resolver.tudelft.nl/uuid:df65da5c-e43f-47ab-b80d-2f8ee7f35464","Improving multigrid for 3-D electro-magnetic diffusion on stretched grids","Jönsthövel, T.B.; Oosterlee, C.W.; Mulder, W.A.","","2006","We evaluated multigrid techniques for 3D diffusive electromagnetism. The Maxwell equations and Ohm's law were discretised on stretched grids, with stretching in all coordinate directions. We compared standard multigrid to alternative multigrid approaches with linewise smoothing and semi-coarsening, both as a stand-alone solver and as a preconditioner. Although the number of iterations was small for some variants, none of the schemes showed grid-independent convergence rates on stretched grids.","electro-magnetics; diffusion; multigrid; controlled-source EM","en","conference paper","Delft University of Technology; European Community on Computational Methods in Applied Sciences (ECCOMAS)","","","","","","","","","","","","",""
"uuid:28496d5f-a8c0-4fcc-a00a-5dc0e6637a59","http://resolver.tudelft.nl/uuid:28496d5f-a8c0-4fcc-a00a-5dc0e6637a59","A new iterative solver for the time-harmonic wave equation","Riyanti, C.D.; Erlangga, Y.A.; Plessix, R.E.; Mulder, W.A.; Vuik, C.; Oosterlee, C.","","2006","The time-harmonic wave equation, also known as the Helmholtz equation, is obtained if the constant-density acoustic wave equation is transformed from the time domain to the frequency domain. Its discretization results in a large, sparse, linear system of equations. In two dimensions, this system can be solved efficiently by a direct method. In three dimensions, direct methods cannot be used for problems of practical sizes because the computational time and the amount of memory required become too large. Iterative methods are an alternative. These methods are often based on a conjugate gradient iterative scheme with a preconditioner that accelerates its convergence. The iterative solution of the time-harmonic wave equation has long been a notoriously difficult problem in numerical analysis. Recently, a new preconditioner based on a strongly damped wave equation has heralded a breakthrough. The solution of the linear system associated with the preconditioner is approximated by another iterative method, the multigrid method. The multigrid method fails for the original wave equation but performs well on the damped version. The performance of the new iterative solver is investigated on a number of 2D test problems. The results suggest that the number of required iterations increases linearly with frequency, even for a strongly heterogeneous model where earlier iterative schemes fail to converge. Complexity analysis shows that the new iterative solver is still slower than a time-domain solver to generate a full time series. We compare the time-domain numeric results obtained using the new iterative solver with those using the direct solver and conclude that they agree very well quantitatively. The new iterative solver can be applied straightforwardly to 3D problems.","seismic waves; geophysical techniques; Helmholtz equations; iterative methods; conjugate gradient methods; differential equations","en","journal article","Society of Exploration Geophysicists","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:8049c0cf-e811-445f-bd69-4a00a6820c82","http://resolver.tudelft.nl/uuid:8049c0cf-e811-445f-bd69-4a00a6820c82","Rapid enterprise design","Mulder, J.B.F.","Dietz, J.L.G. (promotor)","2006","Existing methods for redesigning organizations are often not capable of meeting the required rate of change. This applies in particular to development methods for IT applications: the average automation procedure takes around two years to implement. Therefore, there is an urgent need for methods that make it possible to redesign and restructure organizations, preferably in an integral manner, within a few months. This demands a fundamentally different (scientifically grounded) method that can precisely specify the necessary interaction between the organization, communication, and information (systems). In 1996, this idea formed the impulse for the quest for a method of Rapid Design that could embrace the entire Enterprise. This research describes a ten-year period oriented toward the design of organizations by means of Design & Engineering Methodology for Organizations (DEMO). The study has been assigned the name Rapid Enterprise Design, and cover the rapid design of an organizationâs business functions, business processes, structure, and information provision. In short, the study deals with the issue of whether or not DEMO is an adequate method for the design of both large and small organizations. Investigation was also performed on ways in which DEMO could be further supplemented with a project management method so that it could justifiably be regarded as a completely formal method. For the study, the Action Research method was chosen: a method in which research is performed in stages and research questions are formulated for each stage on the basis of the results of the previous stage. Twenty-eight projects were implemented using DEMO, three of which are described as case studies. In short, the conclusion of the research is that DEMO, supplemented by a project management approach, is an excellent method for the rapid (re)design of both small and large organizations.","organization; business process; information system; organizational structure","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:3da4670d-1d2f-466c-b0d9-f31e86cb81e1","http://resolver.tudelft.nl/uuid:3da4670d-1d2f-466c-b0d9-f31e86cb81e1","Vaartuig voor het overzetten van personen of goederen op een offshoreconstructie","Van der Tempel, J.; Molenaar, D.P.; Mulder, H.; Cerda-Salzmann, D.; Hoonings, S.","","2006","The vessel (3) is for the transfer of persons or goods to an offshore construction (1,2) and has an upper deck (4) with a platform (5) regulatable as to its position. The platform is supported on hydraulically regulated cylinders (6) fitted on the upper deck. Movement sensors (7) are employed to measure the vessel movements and to them is connected a regulating system coupled to the hydraulic regulating systems. This system, dependent upon the vessel movements, adjusts the position of the platform. -","","nl","patent","European Patent Office","","","","","","","","Aerospace Engineering","","","","",""
"uuid:5a280589-aecd-4966-8523-cd7c338a34c5","http://resolver.tudelft.nl/uuid:5a280589-aecd-4966-8523-cd7c338a34c5","Onder de grond kijken","Mulder, W.A.","","2006","","Intreerede","nl","public lecture","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:06ec6c5b-6518-4c9d-9b34-0ba8317cf059","http://resolver.tudelft.nl/uuid:06ec6c5b-6518-4c9d-9b34-0ba8317cf059","Ambipolar Cu- and Fe-phthalocyanine single-crystal field-effect transistors","De Boer, R.W.I.; Stassen, A.F.; Craciun, M.F.; Mulder, C.L.; Molinari, A.; Rogge, S.; Morpurgo, A.F.","","2005","We report the observation of ambipolar transport in field-effect transistors fabricated on single crystals of copper- and iron-phthalocyanine, using gold as a high work-function metal for the fabrication of source and drain electrodes. In these devices, the room-temperature mobility of holes reaches 0.3?cm2/V?s in both materials. The highest mobility for electrons is observed for iron-phthalocyanines and is approximately one order of magnitude lower. Our measurements indicate that these values are limited by extrinsic contact effects due to the transistor fabrication and suggest that considerably higher values for the electron and hole mobility can be achieved in these materials.","copper compounds; iron compounds; organic semiconductors; gold; field effect transistors; hole mobility; electron mobility; work function","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Kavli Institute of Nanoscience","","","",""
"uuid:d7c5551f-9d10-46c4-b35f-2559f302452a","http://resolver.tudelft.nl/uuid:d7c5551f-9d10-46c4-b35f-2559f302452a","The Changing Effect of Home Ownership on Residential Mobility in the Netherlands, 1980-98","Helderman, A.C.; Mulder, C.H.; Van Ham, M.","","2004","In most western countries, homeowners are much less likely to change residence than renters are. In the last few decades, the rise in home ownership in the Netherlands has been spectacular. This would imply that the population has become less mobile, which has consequences for the functioning of the housing market – at least, if the relationship between home ownership and residential mobility has not changed. This research addresses the question whether the effect of home ownership on the probability of residential mobility has changed over the last few decades and if so, how. Using data from the 1981-1998 Netherlands Housing Demand surveys and logistic regression models, we find that the difference between homeowners and renters in residential mobility has changed over time. The results indicate a decrease in the effect of home ownership with an interruption in 1984-85. This finding might indicate stability in the effect of home ownership, except for periods of booms or busts on the housing market.","home ownership; residential mobility; housing market; The Netherlands","en","journal article","Taylor & Francis","","","","","","","","OTB Research Institute for the Built Environment","","","","",""
"uuid:26d279d8-9206-4689-ab2e-23f28dabe3e3","http://resolver.tudelft.nl/uuid:26d279d8-9206-4689-ab2e-23f28dabe3e3","Constraint-based decision support for multi-objective arrival traffic planning","Vormer, F.J.; Boer, E.R.; Van Paassen, M.M.; Mulder, M.; Davison, H.J.","","2003","","air traffic planning; naturalistic decision making; satisficing decision making; situation awareness; human-machine interaction","en","conference paper","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:bc03804e-378a-447b-a6d5-1d0879f5d1b8","http://resolver.tudelft.nl/uuid:bc03804e-378a-447b-a6d5-1d0879f5d1b8","An abstraction hierarchy and functional model of airspace for airborne trajectory planning support","Abeloos, A.L.M.; Van Paassen, M.M.; Mulder, M.","","2003","","situation awareness; ecological interface design; abstraction hierarchy; functional modelling","en","conference paper","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:188b60e8-8aea-4798-9ecc-cb2773090aec","http://resolver.tudelft.nl/uuid:188b60e8-8aea-4798-9ecc-cb2773090aec","An introduction in the ecology of spatio-temporal affordances in airspace","Abeloos, A.L.M.; Mulder, M.; Van Paassen, R.M.M.","","2002","","affordances; alerting systems; aviation; cockpit display design; ecological interface design; ecological psychology","en","conference paper","University of Glasgow","","","","","","","","Aerospace Engineering","","","","",""
"uuid:2ccb99c0-45d9-4a97-ac91-afa921bd21dc","http://resolver.tudelft.nl/uuid:2ccb99c0-45d9-4a97-ac91-afa921bd21dc","Motion simulator with exchangeable unit","Mulder, J.A.; Beukers, A.; Baarspul, M.; Van Tooren, M.J.; De Winter, S.E.E.","","2001","A motion simulator provided with a movable housing, preferably carried by a number of length-adjustable legs, in which housing projection means are arranged for visual information supply, while in the housing a control environment of a motion apparatus to be simulated is situated, the control environment being incorporated in a removable unit, which unit is exchangeable for another, comparable unit having a different control environment to be simulated","","en","patent","European Patent Office","","","","","","","","Aerospace Engineering","","","","",""
"uuid:bd7d0fc7-0f2b-47c4-9c0a-acf0dfd2044e","http://resolver.tudelft.nl/uuid:bd7d0fc7-0f2b-47c4-9c0a-acf0dfd2044e","A generalized class of dynamic translinear circuits","Mulder, J.; Serdijn, W.A.; van der Woerd, A.C.; van Roermund, A.H.M.","","2001","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:a85fb1d0-f8ed-49ea-8bd5-43ebceb6fb17","http://resolver.tudelft.nl/uuid:a85fb1d0-f8ed-49ea-8bd5-43ebceb6fb17","Lithium dynamics in LiMn2O4 probed directly by two-dimensional 7Li NMR","Verhoeven, V.W.J.; de Schepper, I.M.; Nachtegaal, G.; Kentgens, A.P.M.; Kelder, E.M.; Schoonman, J.; Mulder, F.M.","","2001","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:09792ef8-b815-4eb8-b609-d51e96d04bf2","http://resolver.tudelft.nl/uuid:09792ef8-b815-4eb8-b609-d51e96d04bf2","Eco-morphodynamics of the seafloor","Baptist, M.J.; van Bergen Henegouw, C.N.; Boers, M.; van Heteren, S.; Hoogewoning, S.; Hulscher, S.J.M.H.; Jacobse, J.J.; Knaapen, M.A.F.; Mulder, J.P.M.; Passchier, S.; van der Spek, A.J.F.; Storbeck, F.","","2001","","","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:fe9b3927-8758-4076-9146-ed35f70642ab","http://resolver.tudelft.nl/uuid:fe9b3927-8758-4076-9146-ed35f70642ab","Neutron-wave-interference experiments with two resonance coils","Grigoriev, S.V.; Kraan, W.H.; Mulder, F.M.; Rekveldt, M.Th.","","2000","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:a8509a49-d05e-4812-a518-8baee2162269","http://resolver.tudelft.nl/uuid:a8509a49-d05e-4812-a518-8baee2162269","A model for cooperation between humans and intelligent systems","Van Paassen, M.M.R.; Mulder, M.; Abeloos, A.L.M.","","2000","","aircraft cockpit; adaptive interface; intelligent interface; automation; human factors","en","conference paper","European Communities","","","","","","","","Aerospace Engineering","","","","",""
"uuid:e19ddf3e-9372-41e3-a9ec-a739be3e8993","http://resolver.tudelft.nl/uuid:e19ddf3e-9372-41e3-a9ec-a739be3e8993","Integrating aircraft warning systems","Mulder, Mark; Pedroso, O.; Mulder, Max; Van Paassen, M.M.R.","","2000","","agents; multi-agent systems; GPWS; TCAS; integration","en","conference paper","European Communities","","","","","","","","Aerospace Engineering","","","","",""
"uuid:14a35ea9-8f59-4e08-b458-22d78cc08c4e","http://resolver.tudelft.nl/uuid:14a35ea9-8f59-4e08-b458-22d78cc08c4e","The applicabillity of an adaptive human-machine interface in the cockpit","Abeloos, A.L.M.; Mulder, M.; Van Paassen, M.M.R.","","2000","","flight deck; adaptive interface; intelligent interface; automation; human factors","en","conference paper","European Communities","","","","","","","","Aerospace Engineering","","","","",""
"uuid:ad05c643-00d5-49d2-a143-164656012646","http://resolver.tudelft.nl/uuid:ad05c643-00d5-49d2-a143-164656012646","Neutron wave-interference experiments with adiabatic passage of neutron spin through resonant coils","Grigoriev, S.V.; Kreuger, R.; Kraan, W.H.; Mulder, F.M.; Rekveldt, M.Th.","","2000","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:8372d4be-52b3-496e-9ceb-0a0178923f3e","http://resolver.tudelft.nl/uuid:8372d4be-52b3-496e-9ceb-0a0178923f3e","Li mobility in the battery cathode material Lix[Mn1.96Li0.04]O4 studied by muon-spin relaxation","Kaiser, C.T.; Verhoeven, V.W.J.; Gubbens, P.C.M.; Mulder, F.M.; de Schepper, I.; Yaouanc, A.; Dalmas de Reotier, P.; Cottrell, S.P.; Kelder, E.M.; Schoonman, J.","","2000","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:6ac989d2-29e0-4ba5-9611-6747c20656eb","http://resolver.tudelft.nl/uuid:6ac989d2-29e0-4ba5-9611-6747c20656eb","Human machine aspects of arrivals management in future air navigation environments","Vormer, F.j.p.; Mulder, M.; Van Paassen, M.M.R.","","2000","","air traffic control; arrivals management; automation; human machine interaction; perspective displays","en","conference paper","European Communities","","","","","","","","Aerospace Engineering","","","","",""
"uuid:627f30e0-0a70-43f5-b4c8-043c36dda641","http://resolver.tudelft.nl/uuid:627f30e0-0a70-43f5-b4c8-043c36dda641","Cybernetics of Tunnel-in-the-Sky Displays","Mulder, M.","Mulder, J.A. (promotor); Stassen, H.G. (promotor)","1999","Consensus is growing that the flexibility gained with the introduction of programmable, electronic cockpit displays in the 1980s must be exploited to the full extent. An important candidate to become the primary flight display of future flight decks is the tunnel-in-the-sky display, a perspective flight-path display that shows the reference trajectory to be flown in a synthetic three-dimensional world. The usefulness of the tunnel display in the pilot manual aircraft control task is the subject of this thesis. The mainstream of tunnel display research is confined to empirical comparisons of the tunnel display with conventional displays. The approach taken in the present theoretical and experimental study is original and new as it is conducted from the perspective of cybernetics. A four-stage methodology is developed to study the fundamental characteristics of pilot/display interaction, based on a theoretical analysis of information, in particular the information used for control. The information analysis is conducted within the context of Gibson's ecological approach to visual perception. The information analysis provides novel insights into how the tunnel display geometric design variables can affect pilot behavior. To examine the validity of the theoretical hypotheses, six experiments have been conducted. Three experiments examined the effects of manipulating some of the main display design variables, such as the tunnel size, the viewing volume and the presence of guidance symbology. Another three experiments investigated the fundamental characteristics of the tunnel geometrical design in the tasks of following a trajectory that is either straight or circular, and in the task of conducting a curve-interception maneuver. The experiments show that the cybernetic, information-centered approach is indeed very successful in pin-pointing the important characteristics of pilot/display interaction. The experimental methodology employed in this thesis aimed at integrating the model-based approach with the common approach of collecting mainly performance-related data. It is described in detail how experiments can be designed with the objective of conducting a control-theoretic analysis. The limitations of some non-parametric identification methods in multi-axis, multiple loop tracking tasks are described. The use of criterion functions, in both the frequency and the time domain, in the parametric identification methods is also exemplified.","human-machine interface; cockpit displays; perspective displays; cybernetics; human performance modelling","en","doctoral thesis","Delft University Press","","","","","","","","Aerospace Engineering","","","","",""
"uuid:966f60bd-3640-4f03-a80a-c88330c6782e","http://resolver.tudelft.nl/uuid:966f60bd-3640-4f03-a80a-c88330c6782e","Nonlinear analysis of noise in static and dynamic translinear circuits","Mulder, J.; Kouwenhoven, M.H.L.; Serdijn, W.A.; Van Der Woerd, A.C.; Van Roermund, A.H.M.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:c9ee7444-d407-4c49-8ddb-f824ca4dc064","http://resolver.tudelft.nl/uuid:c9ee7444-d407-4c49-8ddb-f824ca4dc064","Flight-path vector symbology in tunnel-in-the-sky displays","Mulder, M.","","1999","","aircraft control; cockpit displays; information analysis; cybernetics","en","conference paper","Group D Publications Ltd","","","","","","","","Aerospace Engineering","","","","",""
"uuid:03506a2a-c4af-4d7e-88ad-183ee9c48687","http://resolver.tudelft.nl/uuid:03506a2a-c4af-4d7e-88ad-183ee9c48687","Free flight's big picture concept: Conceptual design of a cockpit human-machine interface in a ground-controlled free flight environment","Passen, M.M.R.; Mulder, M.; De Vriendt, K.","","1999","","free flight; aircraft displays; human-machine interaction; tunnel-in-the-sky","en","conference paper","Group D Publications Ltd","","","","","","","","Aerospace Engineering","","","","",""
"uuid:664dce12-09d4-41b9-a0c3-4442bb47f2f6","http://resolver.tudelft.nl/uuid:664dce12-09d4-41b9-a0c3-4442bb47f2f6","Static and dynamic translinear circuits","Mulder, J.","Van Roermund, A.H.M. (promotor)","1998","","","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:a650a4eb-9110-4ae8-831b-f86728e27d17","http://resolver.tudelft.nl/uuid:a650a4eb-9110-4ae8-831b-f86728e27d17","An instantaneous and syllabic companding translinear filter","Mulder, J.; Serdijn, W.A.; van der Woerd, A.C.; van Roermund, A.H.M.","","1998","","","","journal article","IEEE","","","","","","","","","","","","",""
"uuid:85cc3a38-bf69-4a95-925c-d5a776a9d1f9","http://resolver.tudelft.nl/uuid:85cc3a38-bf69-4a95-925c-d5a776a9d1f9","An ultra-low-power, low-voltage electronic audio delay line for use in hearing aids","van Dijk, L.P.L.; van der Woerd, A.C.; Mulder, J.; van Roermund, A.H.M.","","1998","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:b70b75c2-117e-45f9-8902-a47e8462aab2","http://resolver.tudelft.nl/uuid:b70b75c2-117e-45f9-8902-a47e8462aab2","Tracking curved trajectories with a tunnel-in-the-sky display","Mulder, M.","","1998","","aircraft control; cockpit displays; information analysis; cybernetics","en","conference paper","LAMIH","","","","","","","","Aerospace Engineering","","","","",""
"uuid:14f4649e-fa82-4cf9-99a0-2c70ef8092ee","http://resolver.tudelft.nl/uuid:14f4649e-fa82-4cf9-99a0-2c70ef8092ee","A wide-tunable translinear second-order oscillator","Serdijn, W.A.; Mulder, J.; van der Woerd, A.C.; van Roermund, A.H.M.","","1998","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:09c17e5a-3638-4384-ae5f-647cdaa85716","http://resolver.tudelft.nl/uuid:09c17e5a-3638-4384-ae5f-647cdaa85716","Noise considerations for translinear filters","Mulder, J.; Kouwenhoven, M.H.L.; Serdijin, W.A.; Van der Woerd, A.C.; Van Roermund, A.H.M.","","1998","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:dd79feeb-f8e1-475f-b49e-a207c00aa3fe","http://resolver.tudelft.nl/uuid:dd79feeb-f8e1-475f-b49e-a207c00aa3fe","The design of a 1330 ktonnes per year low-energy catalytic reformer","Van den Berg, M.M.D.; Janmaat, F.H.; Mulder, J.M.; Nossent, A.J.J.F.","","1997","","catalytic reformer; aromatics; hydrogen sulfide; hydrogen; membrane systems","en","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:d12350a8-0a4f-41f3-828e-c4f4937234ea","http://resolver.tudelft.nl/uuid:d12350a8-0a4f-41f3-828e-c4f4937234ea","Veiligheid en efficientie van luchttransport","Mulder, J.A.","","1997","","Dies Natalis 1997","nl","public lecture","","","","","","","","","","","","","",""
"uuid:c52dd5db-5d96-477f-abc1-881b785b742b","http://resolver.tudelft.nl/uuid:c52dd5db-5d96-477f-abc1-881b785b742b","A reduced-area low-power low-voltage single-ended differential pair","Mulder, J.; van de Gevel, M.; van Roermund, A.H.M.","","1997","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:15c54771-16fb-4af2-9298-5efbb0c0334e","http://resolver.tudelft.nl/uuid:15c54771-16fb-4af2-9298-5efbb0c0334e","A low-voltage ultra-low-power translinear integrator for audio filter applications","Serdijn, W.A.; Broest, M.; Mulder, J.; Van Der Woerd, A.C.; Van Roermund, A.H.M.","","1997","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:3ce6aa4d-c581-4ba7-bd4c-4050680f5e87","http://resolver.tudelft.nl/uuid:3ce6aa4d-c581-4ba7-bd4c-4050680f5e87","High-pressure 155Gd Mössbauer experiments on Gd intermetallic compounds compared with first-principles band-structure calculations","Mulder, F.M.; Coehoorn, R.; Thiel, R.C.; Buschow, K.H.J.","","1997","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:f557eb55-cc20-41bc-9b08-d200bca11738","http://resolver.tudelft.nl/uuid:f557eb55-cc20-41bc-9b08-d200bca11738","An RMS-DC converter based on the dynamic translinear principle","Mulder, J.; Van der Woerd, A.C.; Serdijn, W.A.; Van Roermund, A.H.M.","","1997","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:363161fa-9dd2-48a6-8d77-b0cd673d2344","http://resolver.tudelft.nl/uuid:363161fa-9dd2-48a6-8d77-b0cd673d2344","General current-mode analysis method for translinear filters","Mulder, J.; van der Woerd, A.C.; Serdijn, W.A.; van Roermund, H.M.","","1997","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:568ae092-34a7-4b35-b65e-3fc7691dfd9d","http://resolver.tudelft.nl/uuid:568ae092-34a7-4b35-b65e-3fc7691dfd9d","How do pilots perceive time-to-contact from the ground surface: Results of a visual simulation experiment","Pleijsant, J.M.; Mulder, M.; Van Der Vaart, J.C.; Van Wieringen, P.C.W.","","1996","","","en","conference paper","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:8cbad926-4ed4-46c4-9df8-a0ce66ad274c","http://resolver.tudelft.nl/uuid:8cbad926-4ed4-46c4-9df8-a0ce66ad274c","Modelling manual control of straight trajectories with a perspective flight-path display","Mulder, M.","","1996","","perspective flight-path display; manual controi; human operator modelling","en","conference paper","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:885c2ba6-3146-41d3-8be5-70f351cf4bd5","http://resolver.tudelft.nl/uuid:885c2ba6-3146-41d3-8be5-70f351cf4bd5","Frequency domain identification of multivariable state space models- Analysis procedures and user's guide","Sridhar, J.K.; Soijer, M.; Breeman, J.H.; Mulder, J.A.","","1996","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:763a4817-056a-4942-9e86-b3eab154cdc4","http://resolver.tudelft.nl/uuid:763a4817-056a-4942-9e86-b3eab154cdc4","Anaerobic Oxidation of Ammonium Is a Biologically Mediated Process","Van de Graaf, A.A.; Mulder, A.; De Bruijn, P.; Jetten, M.S.M.; Robertson, L.A.; Kuenen, J.G.","","1995","","nitrosomonas-europaea black-sea nitrite denitrification bacteria oxide; oxidation","en","journal article","","","","","","","","","","","","","",""
"uuid:e03b503b-89be-43ca-af97-17ec20ed1f71","http://resolver.tudelft.nl/uuid:e03b503b-89be-43ca-af97-17ec20ed1f71","Towards a control-theoretic model of pilot manual control behaviour with a perspective flight-path display","Mulder, M.","","1995","","manual control; perspective flight-path displays; human operator modelling","en","conference paper","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:f359a226-ad83-420a-b20e-fca92bdc2afc","http://resolver.tudelft.nl/uuid:f359a226-ad83-420a-b20e-fca92bdc2afc","Anaerobic Ammonium Oxidation Discovered in a Denitrifying Fluidized-Bed Reactor","Mulder, A.; Van de Graaf, A.A.; Robertson, L.A.; Kuenen, J.G.","","1995","","ammonium removal anaerobiosis denitrification waste water nitrification denitrification bacteria; oxidation","en","journal article","","","","","","","","","","","","","",""
"uuid:e7e63efb-b0a8-4daa-a79d-c3e6bb1ca32b","http://resolver.tudelft.nl/uuid:e7e63efb-b0a8-4daa-a79d-c3e6bb1ca32b","MIMO identification techniques and software development in the frequency domain for helicopter and flexible aircraft - Technical results 1994","Sridhar, J.K.; Breeman, J.H.; Mulder, J.A.","","1995","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:4eb4b8d1-88c2-4f2c-9d49-ce0fdc5208dd","http://resolver.tudelft.nl/uuid:4eb4b8d1-88c2-4f2c-9d49-ce0fdc5208dd","Pilot-in-the-loop studies into manual control strategies with perspective flightpath displays","Theunissen, E.; Mulder, M.","","1995","","perspective flightpath displays; aircraft guidance; manual control","en","conference paper","Delft University of Technology","","","","","","","","Electrical Engineering, Aerospace Engineering","","","","",""
"uuid:4efa20a5-75c2-4ea9-8855-eab15e0cc52a","http://resolver.tudelft.nl/uuid:4efa20a5-75c2-4ea9-8855-eab15e0cc52a","Anaerobic oxidation of ammonium is a biologically mediated process","van de Graaf, A.A.; Mulder, A.; de Bruijn, P.; Jetten, M.S.; Robertson, L.A.; Kuenen, J.G.","","1995","","","en","journal article","American Society for Microbiology","","","","","","","","","","","","",""
"uuid:2fb32b05-e8bc-4a1f-a9dc-f8bc1c59df51","http://resolver.tudelft.nl/uuid:2fb32b05-e8bc-4a1f-a9dc-f8bc1c59df51","Application of the back gate in MOS weak inversion translinear circuits","Mulder, J.; van der Woerd, A.C.; Serdijn, W.A.; van Roermund, A.H.M.","","1995","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:0fb09269-47ba-482b-aea7-ed579109de30","http://resolver.tudelft.nl/uuid:0fb09269-47ba-482b-aea7-ed579109de30","MIMO identification techniques and software development in the frequency domain for helicopter and flexible aircraft - Progress report 1994","Sridhar, J.K.; Breeman, J.H.; Mulder, J.A.","","1995","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:10b0ec6e-aaa8-470e-a427-062e6e55ad3c","http://resolver.tudelft.nl/uuid:10b0ec6e-aaa8-470e-a427-062e6e55ad3c","Displays, perception and aircraft control: A survey of theory and modelling of pilot behaviour with spatial instruments","Mulder, M.","","1994","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:aebe34a0-7f5f-44ce-b64d-0a7e11bfdcc5","http://resolver.tudelft.nl/uuid:aebe34a0-7f5f-44ce-b64d-0a7e11bfdcc5","The synthesis of flight simulation models: DATCOM techniques versus flight test identification","Baarspul, M.; Mulder, J.A.","","1993","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:23743a3a-7982-4a97-8f45-709cf506aee1","http://resolver.tudelft.nl/uuid:23743a3a-7982-4a97-8f45-709cf506aee1","Processor architecture and data buffering","Mulder, H.; Flynn, M.J.","","1992","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:d7ca4561-911c-4313-976a-12eab4ad7326","http://resolver.tudelft.nl/uuid:d7ca4561-911c-4313-976a-12eab4ad7326","De stabiliteit en besturing van vliegtuigen: Theorie en praktijk","Mulder, J.A.","","1991","","Intreerede","nl","public lecture","","","","","","","","","","","","","",""
"uuid:74e79655-9e53-41eb-a6ef-37da9143d528","http://resolver.tudelft.nl/uuid:74e79655-9e53-41eb-a6ef-37da9143d528","On the thoughput optimalization of electron beam lithography systems","Mulder, E.H.","Van der Mast, K.D. (promotor); Kuit, P. (promotor)","1991","","","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:8cec92ac-6849-40a2-a778-1c473e779ffc","http://resolver.tudelft.nl/uuid:8cec92ac-6849-40a2-a778-1c473e779ffc","An area model for on-chip memories and its application","Mulder, J.M.; Quach, N.T.; Flynn, M.J.","","1991","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:ae06436e-ca66-42d2-92d2-63d9c20fb0bc","http://resolver.tudelft.nl/uuid:ae06436e-ca66-42d2-92d2-63d9c20fb0bc","Design of a ceramic zeolite membrane","Geus, E.R.; Mulder, A.; Vischjager, D.J.; Schoonman, J.; Van Bekkum, H.","","1991","","membrane zeolite design","en","conference paper","","","","","","","","","","","","","",""
"uuid:391c25c8-8538-469d-add9-7954be849dbf","http://resolver.tudelft.nl/uuid:391c25c8-8538-469d-add9-7954be849dbf","Toervaartroutes door het Groene Hart van Holland: Verslag en conclusies van het symposium gehouden op 27 en 28 september 1989","Dijk, W.J.; Van der Heijden, R.E.C.M.; Mulder, A.F.; Oomen, P.F.","","1990","Sinds enkele jaren leeft binnen de Vakgroep Waterbouwkunde van de Faculteit der Civiele Techniek de wens om in het projectonderwijs meer aandacht te besteden aan de technische voorzieningen ten behoeve van de recreatievaart. De Interfacultaire Werkgroep Recreatie van de T.U.Delft, samengesteld uit vertegenwoordigers van de Vakgroep Waterbouwkunde, de Vakgroep Planning, Ontwerpen en Organisatie en de Werkgroep Civiel-Technisch Projectonderwijs (Faculteit der Civiele Techniek), en van de Vakgroep Ontwerpen van Stedelijke Gebieden en Woningbouw (Faculteit der Bouwkunde) , heeftop27 en 28 september 1989 een symposium georganiseerd onder de titel ""Toervaartroutes door het Groene Hart van Holland"".","vaarroutes; watersportgebieden; ruimtelijke ordening","nl","book","Publikatieburo Bouwkunde","","","","","","","","Architecture","Urbanism","","","",""
"uuid:e272669c-1038-42a7-8384-0c3313c5abf7","http://resolver.tudelft.nl/uuid:e272669c-1038-42a7-8384-0c3313c5abf7","Toervaartroutes door het Groene Hart van Holland","Dijk, W.J.; Van der Heijden, R.E.C.M.; Mulder, A.F.; Oomen, P.F.","","1990","Sinds enkele jaren leeft binnen de Vakgroep Waterbouwkunde van de Faculteit der Civiele Techniek de wens om in het projectonderwijs meer aandacht te besteden aan de technische voorzieningen ten behoeve van de recreatievaart. De Interfacultaire Werkgroep Recreatie van de T.U.Delft, samengesteld uit vertegenwoordigers van de Vakgroep Waterbouwkunde, de Vakgroep Planning, Ontwerpen en Organisatie en de Werkgroep Civiel-technisch Projectonderwijs (Faculteit der Civiele Techniek), en van de Vakgroep Ontwerpen van Stedelijke Gebieden en Woningbouw (Faculteit der Bouwkunde), heeft op 27 en 28 september 1989 een symposium georganiseerd onder de titel ""Toervaartroutes door het Groene Hart van Holland"". Het doel van dit symposium was om grotere bekendheid te geven aan de civiel-technische, civiel-planologische, stedebouwkundige en landschappelijke aspecten van de recreatievaart door het Groene Hart van Holland. Het symposium was primair bedoeld voor studenten civiele techniek, die in de vorm van projecten met deze problematiek aan de gang gingen.","watersportgebieden; Nederland vaarroutes; ruimtelijke ordening","nl","book","Publikatieburo Bouwkunde","","","","","","","","Architecture","Urbanism","","","",""
"uuid:7d630093-16dc-4912-8fb7-def0f449d855","http://resolver.tudelft.nl/uuid:7d630093-16dc-4912-8fb7-def0f449d855","The advanced automatic flight control systems project","Kruijsen, E.A.C.; Mulder, J.A.","","1990","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:4e5b3c2a-8229-4631-9934-820a998a8e4e","http://resolver.tudelft.nl/uuid:4e5b3c2a-8229-4631-9934-820a998a8e4e","Anoxic ammonium oxidation","Van de Graaf, A.A.; Mulder, A.; Slijkhuis, H.; Robertson, L.A.; Kuenen, J.G.","","1990","","oxidation; wastewater denitrification ammonium oxidn","en","conference paper","","","","","","","","","","","","","",""
"uuid:15b6fdf1-8994-4379-8e2c-269aaef5fcb4","http://resolver.tudelft.nl/uuid:15b6fdf1-8994-4379-8e2c-269aaef5fcb4","Essays on stability and control","Baarspul, M.; Mulder, J.A.","","1989","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:cc14a640-f424-40ab-bc77-d41c60bd2566","http://resolver.tudelft.nl/uuid:cc14a640-f424-40ab-bc77-d41c60bd2566","Winkeltijden en congestie: Effecten van een verruimd openingsregime van winkels en diensten op de verkeerscongestie","Tacken, M.; Mulder, J.C.","","1988","","","nl","book","Delft University Press","","","","","","","","Architecture","","","","",""
"uuid:2411db5e-3471-4c3b-bdab-e3b07ab9a4c5","http://resolver.tudelft.nl/uuid:2411db5e-3471-4c3b-bdab-e3b07ab9a4c5","Mathematical model identification for flight simulation, based on flight and taxi tests","Baarspul, M.; Mulder, J.A.; Nieuwpoort, A.H.M.; Breeman, J.H.","","1988","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:59cfe192-8602-49c7-921c-0fb48f6e6406","http://resolver.tudelft.nl/uuid:59cfe192-8602-49c7-921c-0fb48f6e6406","Stability and control derivatives of the De Havilland DHC-2 ""Beaver"" aircraft","Tjee, R.T.H.; Mulder, J.A.","","1988","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:31c246a3-b940-4799-abc8-34cbf6d4bc3c","http://resolver.tudelft.nl/uuid:31c246a3-b940-4799-abc8-34cbf6d4bc3c","Financieringsmogelijkheden voor nieuwe vormen van woningbeheer: Een onderzoek naar de financiering van woonprojecten met andere eigendoms- en beheersverhoudingen","Mulder, A.; Kroes, J.H.; IJmkers, F.","","1987","","huisvestingsbeleid; Nederland","nl","book","Delftse Universitaire Pers","","","","","","","","","","","","",""
"uuid:166e304d-e5e1-4027-9d80-b79cd743fff7","http://resolver.tudelft.nl/uuid:166e304d-e5e1-4027-9d80-b79cd743fff7","Determination of the mathematical model for the new dutch government civil aviation flying school flight simulator","Mulder, J.A.; Baarspul, M.; Breeman, J.H.; Nieuwpoort, A.M.H.; Verbraak, J.P.F.; Steeman, P.S.J.M.","","1987","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:dc8cee18-321c-4a75-8aab-65ee6e7c2553","http://resolver.tudelft.nl/uuid:dc8cee18-321c-4a75-8aab-65ee6e7c2553","Arbeidstijdverkorting en vervoerpieken: Een prognose voor 1990","Tacken, M.; Mulder, J.C.","","1986","Onderzoek in opdracht van Ministerie van Verkeer en Waterstaat, Project Integrale Verkeers- en Vervoerstudies.","arbeidstijdverkorting; mobiliteitsonderzoek; openbaar vervoer; verkeersstromen","nl","book","Delftse Universitaire Pers","","","","","","","","Architecture","","","","",""
"uuid:a6d75095-1908-472a-9d7b-cfdf313908fd","http://resolver.tudelft.nl/uuid:a6d75095-1908-472a-9d7b-cfdf313908fd","Design and evaluation of dynamic flight test manoeuvres","Mulder, J.A.","Gerlach, O.H. (promotor); Eykhoff, P. (promotor)","1986","","","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:5c26010c-5e3a-4344-8163-8be7d12077f1","http://resolver.tudelft.nl/uuid:5c26010c-5e3a-4344-8163-8be7d12077f1","Calibration characteristics and error statistics of a high accuracy flight test instrumentation system for measurements in dynamic flight test manoevres","Kranenburg, C.G.; de Lange, P.; Mulder, J.A.","","1986","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:c9201aec-cdc9-43f3-9f90-ce896425dffe","http://resolver.tudelft.nl/uuid:c9201aec-cdc9-43f3-9f90-ce896425dffe","Design and evaluation of dynamic flight test manoeuvres","Mulder, J.A.","","1986","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:d950e9c6-89d6-4e2a-92a4-4f117982c4fc","http://resolver.tudelft.nl/uuid:d950e9c6-89d6-4e2a-92a4-4f117982c4fc","Elementary data analysis of measurements in nonsteady longitudinal and lateral flight test manoeuvres","Kranenburg, C.G.; de Lange, P.; Mulder, J.A.","","1986","","Vliegtests; gegevensverwerking","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:a4554b80-beb9-4c9c-ab62-8b2413645be4","http://resolver.tudelft.nl/uuid:a4554b80-beb9-4c9c-ab62-8b2413645be4","Change of viscosity during structural relaxation of amorphous Fe40Ni40B20","Van den Beukel, A.; Huizer, E.; Mulder, A.L.; Van der Zwaag, S.","","1986","","","en","journal article","","","","","","","","","","","","","",""
"uuid:36b5d2d4-350d-44be-adf2-37f4cbdaae46","http://resolver.tudelft.nl/uuid:36b5d2d4-350d-44be-adf2-37f4cbdaae46","Experimentele woningbouw: Project 'De Bergen' Capelle a/d IJssel","Laddé, E.E.; Dubbeld, G.; Van Ham, K.; Mulder, A.F.; Pluijmers, B.J.; Post, J.M.; Scheers, P.M.C.","","1985","","Nederland; experimentele woningbouw; Capelle a/d IJssel","nl","book","Delftse Universitaire Pers","","","","","","","","Architecture","","","","",""
"uuid:05ab6ea9-c801-4348-8926-6463faab5120","http://resolver.tudelft.nl/uuid:05ab6ea9-c801-4348-8926-6463faab5120","Een model voor een industrieele afvalwaterzuiveringsinstallatie: Een overzicht","Mulder, W.H.","","1984","Document(en) uit de collectie Chemische Procestechnologie.","","nl","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:fddf8a97-4181-4893-97d9-f86eb01a7ce2","http://resolver.tudelft.nl/uuid:fddf8a97-4181-4893-97d9-f86eb01a7ce2","On the Kinetics of Structural Relaxation in Amorphous Fe40Ni40B20","Mulder, A.L.; Van der Zwaag, S.; Van den Beukel, A.","","1984","","","en","journal article","","","","","","","","","","","","","",""
"uuid:0846ead5-3dac-4337-8fef-041d54d78ed9","http://resolver.tudelft.nl/uuid:0846ead5-3dac-4337-8fef-041d54d78ed9","Accurate Contraction and Creep Measurements During Structural Relaxation of Amorphous Fe40Ni40B20","Mulder, A.L.; Van der Zwaag, S.; Huizer, E.; Van den Beukel, A.","","1984","","","en","journal article","","","","","","","","","","","","","",""
"uuid:1bd12c5a-8ec5-441b-bffb-fad1835c8905","http://resolver.tudelft.nl/uuid:1bd12c5a-8ec5-441b-bffb-fad1835c8905","Embrittlement and Disembrittlement in Amorphous Metglas 2826-A","Mulder, A.L.; Van der Zwaag, S.; Van den Beukel, A.","","1983","","","en","journal article","","","","","","","","","","","","","",""
"uuid:ff893017-4ca4-4006-ba5a-48616273575c","http://resolver.tudelft.nl/uuid:ff893017-4ca4-4006-ba5a-48616273575c","Aerodynamic model identification from dynamic flight tests data and windtunnel experiments","Mulder, J.A.; den Hollander, J.G.; Binkhorst, H.","","1982","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:240c1a7c-1bce-46d5-9df4-0df67a4d148d","http://resolver.tudelft.nl/uuid:240c1a7c-1bce-46d5-9df4-0df67a4d148d","Flight path reconstruction in the context of nonsteady flight testing","Horsten, J.J.; Jonkers, H.L.; Mulder, J.A.","","1979","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:324df0d5-6787-4d3c-9403-72ded7be9c38","http://resolver.tudelft.nl/uuid:324df0d5-6787-4d3c-9403-72ded7be9c38","Beschrijving van het Tape-2 rekenprogramma voor de verwerking van metingen in niet-stationaire symmetrische vlucht met het laboratoriumvliegtuig Hawker MkVII, PH-NLH","De Lange, P.; Mulder, J.A.; Verkerk, P.J.","","1977","","","nl","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:04777e4a-260b-453f-9f36-d6b1166227bf","http://resolver.tudelft.nl/uuid:04777e4a-260b-453f-9f36-d6b1166227bf","NOx-verwijdering uit de afgasstroom van een HNO3-fabriek m.b.t. een H2SO4-fabriek","Mulder, W.; Ockhuysen, J.","","1976","Document(en) uit de collectie Chemische Procestechnologie.","","nl","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:4e71c060-d8e7-497a-b765-cc067432abc8","http://resolver.tudelft.nl/uuid:4e71c060-d8e7-497a-b765-cc067432abc8","Estimation of drag and thrust of jet-propelled aircraft by non-steady flight test manoeuvres","Mulder, J.A.; van Sliedrecht, J.M.","","1976","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:3399118f-205e-471c-bd67-eee45588da3a","http://resolver.tudelft.nl/uuid:3399118f-205e-471c-bd67-eee45588da3a","Territoriumverschijnselen in een recreatielandschap; een sociaal-geografisch onderzoek naar de structuur van het territorium en naar de plaatskeuze in de vrije tijd bij bewoners van 'De Fransche Kamp' te Bussum","Mulder, A.F.","De Vries Reilingh, H.D. (contributor); Van Paassen, C. (contributor)","1974","","","nl","book","Delftse Universitaire Pers","","","","","","","","","","","","",""
"uuid:fde0051a-4c92-4160-a4d9-6e55bbcd4b2b","http://resolver.tudelft.nl/uuid:fde0051a-4c92-4160-a4d9-6e55bbcd4b2b","Estimation of the aircraft state in non-steady flight","Mulder, J.A.","","1974","","","en","report","Delft University of Technology","","","","","","","","Aerospace Engineering","","","","",""
"uuid:7bc61dad-2efd-4669-97d1-d753fc298a5d","http://resolver.tudelft.nl/uuid:7bc61dad-2efd-4669-97d1-d753fc298a5d","Arrival Trajectory Optimization on Noise Impact using Interval Analysis","Yu, H.; Mulder, J.A.","","","The CleanEra project is initiated by the Faculty of Aerospace Engineering at Delft University of Technology. Significant reduction of noise impact on perimeters of airports via arrival trajectory optimization is considered as one of the major targets of the project. In this paper, an aircraft model and its acoustic performance are introduced to assist the development of the optimization tool since the CleaenEra project is still ongoing. Interval analysis is explained in details because interval algebra is employed to deal with real intervals rather than real numbers in the so-called interval-related optimization algorithms. The largest advantage of such algorithms is that they are capable of finding the global optimum out of the multiple local minima to a given optimization problem. Two numerical examples are presented to show the usefulness of such algorithms while solving both static and dynamic optimization problems. In the end, a third example is given to demonstrate the applicability of the proposed optimization tool to trajectory optimization for arriving passenger aircraft.","","en","conference paper","American Institute of Aeronautics and Astronautics (AIAA)","","","","","","","","Aerospace Engineering","Control & Operations","","","",""
"uuid:b81b04d6-d680-40b2-821e-8e4a82d661f1","http://resolver.tudelft.nl/uuid:b81b04d6-d680-40b2-821e-8e4a82d661f1","Ontwerp van een kontinue desublimator voor het scheiden van gasmengsels","Mulder, A.E.M.; Segers, R.","","1967","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:1a92529f-63fe-40af-840e-984162fb5d91","http://resolver.tudelft.nl/uuid:1a92529f-63fe-40af-840e-984162fb5d91","Bereiding van butylmercaptaan uit buteen-1 en H2S","Mulder, J.W.A.M.","","1952","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University of Technology","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:a99fb804-df37-428a-8ac6-c81614cb0ecb","http://resolver.tudelft.nl/uuid:a99fb804-df37-428a-8ac6-c81614cb0ecb","Ontwerpschema voor een melkzuurfabriek","Mulder, W.C.","","1949","Document(en) uit de collectie Chemische Procestechnologie","","nl","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:87f1576a-4e57-43ec-b42b-83521f7bced0","http://resolver.tudelft.nl/uuid:87f1576a-4e57-43ec-b42b-83521f7bced0","Het fabrieksschema van boorzuur","Mulder, E.J.","","1948","Document(en) uit de collectie Chemische Procestechnologie","borium fluoride","en","report","Delft University","","","","","","","","Applied Sciences","DelftChemTech","","","",""
"uuid:a9672e6a-3ddd-4b7f-a1b4-b53ced6a7d76","http://resolver.tudelft.nl/uuid:a9672e6a-3ddd-4b7f-a1b4-b53ced6a7d76","De ontwikkeling van gloeidraad-gelijkrichterbuizen, in het bijzonder van die voor hooge spanning","Mulder, J.G.W.","Dorgelo, H.B. (promotor)","1934","","","nl","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""