Hochschule für Architektur, Bau und Geomatik FHNW
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Bereich: Suchergebnisse
Publikation Simulation of policies for automated ride-hailing and ride-pooling services(05.01.2025) Kagho, Grace; Balac, Milos; van Eggermond, Michael; Erath, AlexanderAutomated vehicles are becoming more prevalent, and the disruption they would cause in combination with ride-hailing and ride-pooling services could be tremendous. Therefore, this study investigates the impacts of ride-hailing and ride-pooling automated fleets in two Swiss cities, Chur and Zurich, and potential policy measures to steer their operations towards more sustainable solutions. We employ the results of the stated preference survey and combine the estimated mode-choice and car ownership model results with the agent-based simulation, MATSim, to simulate the impacts of various scenarios. We find that automated ride-hailing (aRH) and automated ride-pooling (aRP) services do not seem to be competing for the same demand. In general, these services would lead to a reduction in total travel time but an increase in total vehicle distance, which is more substantial in transit-oriented Zurich than in car-oriented Chur. Furthermore, we found that even though the proposed policies increased vehicle occupancy, they did not manage to overcome the increase in VKT, signaling the need for more targeted policies and operational strategies. Finally, we provide recommendations for transport policy and future research based on our findings.04B - Beitrag KonferenzschriftPublikation Comparing Q347 development and regionalization using recent data in two Swiss cantons(09.11.2024) Dups, Yanick; Lebrenz, HenningIn Switzerland, low flows are characterized by the discharge level corresponding to a 95% exceedance probability on a ten-year average flow duration curve, referred to as Q347. This threshold not only has significant implications for planning but also requires authorities to adjust the operation of relevant infrastructure to mitigate ecological impacts on watercourses. The value of Q347 can be determined from a flow duration curve if a discharge time series of at least ten years is available. However, for smaller catchments such time series are typically unavailable, necessitating the regionalization of Q347 values. In Switzerland, multiple linear regression has been established to estimate the area-specific discharge q347 for ungauged basins. The primary objective of this study was to regionalize Q347 values for small, ungauged catchments (383 in the Canton of Solothurn and 9'034 in the Canton of Zürich) each with an area of less than 100 km². Daily discharge, precipitation, and temperature time series were collected for a 30-year study period from 1990 to 2020 from 56 gauged catchments in Solothurn, and similarly for a ten-year study period from 2013 to 2023 in Zürich, focusing on catchments smaller than 500 km² surrounding the target areas. A total of 30 “static” parameters delineating geometry, topography, geology, land use, and drainage along with nine “climatic” parameters describing temperatures, precipitation distributions, and potential evapotranspiration were defined and computed to characterize both gauged and ungauged catchments. The temporal variability of low flow events was then analysed for observed catchments in the two study areas. Over the past 30 years, the frequency of low flow events below the threshold has systematically increased, while the ten-year Q347 values for these catchments have decreased during the same period. Three multiple linear regression methods were developed and implemented to be coupled with two adjustment techniques supplementing truncated discharge time series. Validation of the proposed models showed reduced errors and increased linear correlations between estimated and observed values compared to standard models. Notably, a spatially more homogeneous yet catchment-specific distribution of estimated values is observable. The proposed models yielded promising results, particularly when time series remain unadjusted, or adjustment is done using the Antecedent Precipitation Index (API) combined with the flow duration curve of a donor basin (Ridolfi et al., 2020). Using recent data for parameter selection and model fitting, especially in the Zürich study area (2013-2022), often resulted in lower Q347 values compared to standard models, reflecting an adaptation to current climatic trends.06 - PräsentationPublikation Simulationsgestützte Systemauslegung für sorptionsgestützte, solare Kälteanlagen(VDI Fachmedien, 2022) Bürger, Adrian; Sawant, Parantapa; Wittstadt, Ursula; Altmann-Dieses, Angelika; Pfafferott, JensDie fluktuierende Verfügbarkeit regenerativer Energiequellen stellt eine Herausforderung bei der Planung und Auslegung regenerativer Gebäudeenergiesysteme dar. Die in einem System benötigten Speicherkapazitäten hängen dabei sowohl von der eingesetzten Regelungsstrategie als auch von den temperaturabhängigen Wirkungsgraden der Anlagenkomponenten ab. Genauere Einblicke in das Betriebsverhalten eines Gesamtsystems können dynamische Simulationen liefern, die eine Analyse der Systemtemperaturen und von Teilenergiekennwerten ermöglichen.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Virtual reality and choice modelling. Existing applications and future research directions(Edward Elgar Publishing, 2024) van Eggermond, Michael; Mavros, Panos; Erath, Alexander; Hess, Stephane; Daly, AndrewResearch eliciting individuals’ preferences, including stated preference (SP) research, have long utilised imagery as stimuli to visualise either attributes or situations deemed too complex to be expressed verbally. The advent of Virtual Reality (VR) offers choice modelers with exciting new opportunities. This chapter outlines key concepts underlying VR and summarises previous research combining VR and choice modeling. It provides a framework of different dimensions that should be considered when developing VR experiments, including technological aspects (display technology and movement) and other aspects, such as survey duration, motion sickness and the representation of time. The chapter concludes with several ways to further combine choice modeling and VR.04A - Beitrag SammelbandPublikation Model predictive control for energy-efficient optimization of radiant ceiling cooling systems(Elsevier, 11/2021) Koch, Manuel; Qiong Chen; Nan LiState-of-the-art model predictive control (MPC) applications have been performed in various heating and cooling systems of buildings, such as fan coil unit systems and radiant floor heating systems. However, there is also a significant potential for improved zone air temperature control for better thermal comfort and efficient energy savings in increasingly prosperous radiant ceiling cooling systems. In this research, the physics-based model was developed by applying the building envelope configuration and material property information. The reduced order model of the original radiant ceiling cooling system model was then simplified using the balanced trun cation method for reducing computational cost and maintaining a comparative model accuracy. The model predictive control of radiant ceiling cooling systems was proposed for zone air temperature tracking, allowing the system to be more robust and adaptive to external thermal disturbances such as solar radiation and ambient temperature. The superior performance of model predictive control in terms of accurate zone air temperature tracking and energy efficiency was evaluated by a simulation compared to PID control and conventional bang bang control in both continuous and intermittent operation. The proposed model predictive control can achieve 21%–27% and 6% energy saving efficiency, compared with PID control and conventional bang-bang control, respectively. And there is rarely any overshoot or steady-state error presence for the zone air temperature, which demonstrated the significant potential of the robust model redictive control for better thermal comfort and efficient energy savings in growing prosperous radiant ceiling cooling systems.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Event-based flood estimation using a random forest algorithm for the regionalization in small catchments(Eigenverlag des Instituts für Wasser- und Umweltsystemmodellierung, 07/2022) Pavía Santolamazza, DanielaThe hydrological cycle is a complex system, composed of multiple variables, which in most cases are not measured. This is one of the reasons why it is a challenge to have models that adequately represent the expected discharges. The PUB initiative reinforces the need on having models that capture the different catchment interactions and represent various catchment processes. These models are more robust and thus can be more reliable to transfer to the ungauged catchments. In recent years, the field of hydrological research has focused on understanding and explaining the different processes present in catchments. Nevertheless, few applications that include pre- cipitation, the main responsible of runoff change,are found.Further understanding of the temporal and spatial dependence of the meteorological event triggering the floods is needed. In this study, an analysis of the meteorological event triggering the floods was carried out. The concept of entropy was used to characterize the temporal distribution of precipitation. It was found that the precipitation temporal entropy is a better indicator of hydrograph shape than the duration or the intensity. Further, the geographical interdependence of the amount of precipitation and the temporal precipitation entropy causing the floods was described looking at the association of sta- tions triples. This suggested that, up until a given quantile, flood events are more likely caused by precipitation events of total coverage. However, for larger quantile values, it is observed that as the quantile increases the probability of observing joint occurrence in space decreases. The tem- poral distribution of precipitation events causing the floods showed to be more associated in space than the amount of precipitation triggering the floods. Nonetheless, this temporal distribu- tion is not constant over all flood events, what can be attributed to d ifferent flood mechanisms. The Antecedent Precipitation Index (API) was used to explain the soil moisture content. The em- pirical distribution of (API) at the time of a flood was compared with empirical distributions of unconditioned (API) data series. T o this end, the Wilcoxon statistic and the Kolmogorov -Smirnov distance were used to compare the empirical distributions. The re sults showed that the soil mois- ture triggering the floods is not an annual extreme, rather a value close to the monthly maximum (API). Further, it was observed that the longer memory of the catchment gives more information about the occurrence of the flood. Additionally, in order to estimate the catchment reaction at the time of a flood, a regiona lization of the flood wave hydrographs was carried out. T o this end, three methods of defining the simi- larity of the floods were considered. In all three methods, the similarity matrices were generated using the random forest algorithm. The novelty of this procedure was the use of a supervised random forest to describe the similarity of the floods events. It was supervised given that the algorithm was trained to estimate a target variable. The proximity matrix was obtained by calcu- lating the joint occurrence of floods in the random forest space. For evaluating the estimation the hydrograph peak and the time to peak were used. In all three methods, the same tendencies were observed, an overestimation of the peak and an underestimation of the time to peak. However, the bias was observed to be smaller when an ensemble of similarity matrices was used as com- pared to having a single similarity matrix. Moreover, an approach using an unsupervised random forest was compared to the supervised one. It was found that the unsupervised random forest yields larger estimation errors. Finally, to estimate the volume of the flood event a rainfall-runoff model was modified to represent the study region. The model chosen in this study was EPIC. The model was calibrated to be more representative of the study region. To this end, the estimation errors in the space of the model parameters were studied. This allowed to find the model parameters that can better represent the study area. The values obtained were considered reasonable. For example, it is observed that the longer memory of the catchment is more representative of the study catchments, which are the same results as when analyzing the meteorological phenomenon causing the floods. Further, the values obtained for the regional constant, parameter modifying the initial abstraction of the catchment, were found to be smaller than the original ones obtained for United States catchments, which agrees with other studies in European catchments.02 - MonographiePublikation Nachhaltige Ansätze zur Parkraumplanung(Bundesamt für Strassen, 09.07.2024) Erath, Alexander; van Eggermond, Michael; Sieber, Mark; Graf, Samuel; Perret, Fabienne05 - Forschungs- oder ArbeitsberichtPublikation Parameterization and results of SWE for gravity currents are sensitive to the definition of depth(American Society of Civil Engineers, 12.03.2021) Venuleo, Sara; Pokrajac, Dubravka; Tokyay, Talia; Constantinescu, George; Schleiss, Anton J.; Franca, Mário J.Rigorously derived shallow water equations (SWEs) are applied to results of large eddy simulation (LES) of a continuously fed gravity current in order to assess (1) sensitivity of current depth results to its definition; (2) coefficients in depth-averaged continuity and momentum equation due to the nonuniformity of density and velocity profiles; and (3) sensitivity of entrainment coefficient to definition of current depth. It is shown that using different definitions of the current depth may produce significantly different numerical results. The coefficients due to nonuniformity in the continuity equation are very close to unity, whereas the coefficients in the momentum flux and the pressure term in the momentum equation are different from unity by a margin that is very sensitive to the definition of current depth. The entrainment coefficient is more sensitive to the selected parameterization than to the definition of the current depth.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Analysis of the resolution of precipitation data required to obtain robust results from a hydrodynamic sewer network model(19.04.2024) Rabiei, Ehsan; Hoppe, Holger; Lebrenz, HenningThe need for precipitation data for calibrating hydrodynamic sewer network models is often compromised by using the nearest available rain gauges to study area. Due to the scarcity and irregular locations of the rain gauges, this way of satisfying the need for precipitation data can lead to incorrect conclusions with respect to the temporal and spatial patterns of precipitation, depending on the location of the rain gauges in the study area. Recent developments in the field of precipitation measurement by means of weather radar data open up new possibilities for the use of such data sources in hydrodynamic sewer network models. Even though weather radar provides precipitation information with a high temporal and spatial resolution, the raw radar data contains several sources of error and is inaccurate. The radar data are therefore often corrected and merged with ground measurements. The main objective of this study is to investigate the resolution of precipitation data required to obtain robust results in a hydrodynamic channel network model. The study area is a small catchment close to Munich in Bavaria, Germany. Data from the Isen weather radar station of the German Weather Service (DWD), which is located around 33 km from the study area, was used. Following the objectives of this study, various weather radar data products were processed in order to be used as input for a hydrodynamic sewer network model. The data with a temporal resolution of 5 minutes to 1h and a spatial resolution of 250 m x 250 m up to 1.000 m x 1.000 m form the basis for creation of datasets to be investigated. It has been observed that the use of high-resolution precipitation data leads to better model results, especially when the data is merged with rain gauges. However, it should be noted that the quality of the model results does not decrease linearly when the resolution of the precipitation data is reduced.06 - PräsentationPublikation Physikalische Modellierung des Geschiebetransports für «WieseVital»(Schweizerischer Wasserwirtschaftsverband, 03/2024) Venuleo, Sara; Unrau, Silas; Guido Derungs; Lebrenz, HenningDas Revitalisierungsprojekt «WieseVital» (BS) sieht den Einbau einer grobkörnigen Schutzschicht über die gesamte Gewässersohle sowie punktuell eingebrachtes, feinkörniges Laichsubstrat vor. Um die Interaktion der beiden Kornfraktionen, insbesondere den Einfluss der Feinsedimente auf die grobkörnige Schutzschicht zu beurteilen, wurde an der Fachhochschule Nordwestschweiz (FHNW) ein physikalisches Wasserbaumodell im Massstab 1:20 nachgebaut. Unter Beachtung von Skalierungseffekten und den abgeleiteten Rand- und Übertragungsbedingungen, konnten wertvolle Grundlagen und Hinweise für den Bau und den Betrieb des geplanten Flussabschnitts gewonnen werden. Das eingebrachte feinkörnige Laichsubstrat verteilt und vermischt sich bis zur Vermischungstiefe, die durch «kinetische Siebung» (z. B. beim HQ100) deutlich erhöht werden kann. Im Allgemeinen erleichtern die Feinsedimente den Bewegungsbeginn der grobkörnigen Schutzschicht, ohne allerdings ihre Stabilität zu gefährden. Ergänzend können erhöhte Kolkbildungen an geplanten ökologischen Einbauten durch lokale Sohlsicherungsmassnahmen begrenzt werden. Im späteren Betrieb kann das Modell von Wilcock & Crowe für die Abschätzung der gesamten Geschiebefracht angewendet werden, falls die raumzeitliche Verteilung der notwendigen Gewässersohleneigenschaften bekannt ist.01B - Beitrag in Magazin oder Zeitung
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