88 research outputs found
Beiträge zur kombinierten Lichtstreuung in trüben Medien und an rauen Oberflächen
No full textDiese Arbeit beschäftigt sich mit der kombinierten Lichtstreuung in trüben Medien und an rauen Oberflächen. Die Arbeit enthält vier vom Autor veröffentlichte Artikel zum Thema der Herstellung rauer Oberflächen und der Wechselwirkung zwischen Lichtstreuung in trüben Medien und an rauen Oberflächen. Zusätzlich erläutert eine Einleitung die Eigenschaften und Charakterisierungsmöglichkeiten rauer Oberflächen und es wird eine Anwendung der gewonnen Erkenntnisse präsentiert.This thesis deals with the combined light scattering in turbid media and on rough surfaces. The work contains four articles published by the author on the subject of the production of rough surfaces and the interaction between light scattering in turbid media and on rough surfaces. In addition, an introduction explains the properties and characterization possibilities of rough surfaces and an application of the knowledge gained is presented
ERTMS/ETCS Hybrid Level 3: A simulation-based impact assessment for the Dutch railway network
No full textBlock signalling and Automatic Train Protection are two of the main railway safety systems to control the risk of train accidents. The combination of the existing Dutch block signalling system NS’54 and ATP-system ATB-EG is functioning well, but has some drawbacks. The systems have been designed over 60 years ago with proven technology of that time. Components are old and will have to be replaced in the near future. The safety functionality of the legacy systems is limited. Moreover, the capacity of the Dutch railway network with NS’54/ATB-EG is almost fully used while demand grows. Solutions are required to match the demand growth. The European Rail Traffic Managements System (ERTMS) is proposed to be the new standard European safety system. Train control is included in the European Train Control System (ETCS). It offers benefits in the form of interoperability, increased safety, speed, capacity and/or reliability over the national system. ERTMS/ETCS Hybrid Level 3 is an integrated cab-signalling and train protection system that combines train position information, onboard train integrity confirmation and trackside train detection. Compared to the legacy system NS'54/ATB-EG and the proposed system ERTMS/ETCS Level 2 it offers more railway capacity and allows for a reduction in trackside train detection. This thesis shows that the infrastructure occupation can drop from 84% to 66,7% when implementing ERTMS/ETCS Hybrid Level 3. Reducing the amount of trackside train detection to the minimum and transitioning from track circuits to axle counters can result in a decrease of track unavailability related to train protection systems of over 40% compared to the existing configuration.Civil Engineerin
Family Assessment- Author Index
Full text linkAuthor Index (12 pages)
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Abbott, D.: 263 Abery, B.: 242 Abidin, R: 81, 265 Abramovitch, R: 134, 135, 136, 137, 139,142,143,144,145,146 Abril, s.: 118 Achenbach, T. M.: 12,47, 118, 223, 265 Acock, A. c.: 206 Adams, G. R: 205 Adams, S. J.: 226 Al-Khayyal, M.: 74 Alexander, J. F.: 75 Allisson, P. D.: 185 Alwin, D. F.: 182,191,194 Amato, P. R: 205- 231, 206, 207, 210, 213,215,216, 219, 221, 222, 224, 227,230 Ammerman, R : 263 Amoloza, T. 0 .: 170, 171,172,176, 179, 187, 188 Anastasi, A.: 265 Anderson, B. J.: 85 Anderson, c.: 117 Anderson, P. P.: 104 Anderson, S. A.: 79, 168, 177 Anthony, J.: 117 Apley, J.: 84 Aponte, H. J.: 117 Appelbaum, M.: 263 Arrington, A.: 11 Asher, S.: 82 Asterita, M. F. : 92 Attneave, c.: 121 Auslander, W. F: 85
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Zane, N .: 107, 119 Zetlin, A.: 263 Zill, N.: 83 Zuo, J.: 171, 180, 18
Family Assessment- Author Index
Full text linkAuthor Index (12 pages)
A-Z
A
Abbott, D.: 263 Abery, B.: 242 Abidin, R: 81, 265 Abramovitch, R: 134, 135, 136, 137, 139,142,143,144,145,146 Abril, s.: 118 Achenbach, T. M.: 12,47, 118, 223, 265 Acock, A. c.: 206 Adams, G. R: 205 Adams, S. J.: 226 Al-Khayyal, M.: 74 Alexander, J. F.: 75 Allisson, P. D.: 185 Alwin, D. F.: 182,191,194 Amato, P. R: 205- 231, 206, 207, 210, 213,215,216, 219, 221, 222, 224, 227,230 Ammerman, R : 263 Amoloza, T. 0 .: 170, 171,172,176, 179, 187, 188 Anastasi, A.: 265 Anderson, B. J.: 85 Anderson, c.: 117 Anderson, P. P.: 104 Anderson, S. A.: 79, 168, 177 Anthony, J.: 117 Apley, J.: 84 Aponte, H. J.: 117 Appelbaum, M.: 263 Arrington, A.: 11 Asher, S.: 82 Asterita, M. F. : 92 Attneave, c.: 121 Auslander, W. F: 85
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Zane, N .: 107, 119 Zetlin, A.: 263 Zill, N.: 83 Zuo, J.: 171, 180, 18
Optical phantoms and photonic applications of two-photon polymerization
No full textThis work deals with the potential applications of 2-photon polymerization with particular reference to its use in the fabrication of complex optical phantoms. The work contains 5 journal articles which were written by the author in the context of his research activities as well as an introduction that explains the two subfields and puts them into context
Fritz von Unruh Collection. 1951-1954
No full textThis collection contains a eulogy for Alwin Kronacher (German-born American dramaturgical consultant, actor and director) (1951); two theatrical programs for Fritz von Unruh plays (1952-1953); and a biographical sheet (1954).Author, 1885-1970The original German language inventory is available in the folderProcessed for digitizationdigitize
Studies of light propagation inside turbid media and scattering mitigation by phase-optimized light beams
No full textIn this doctoral thesis, the propagation of light in scattering and absorbing media is investigated through solutions of the radiative transfer equation and numerical solutions of Maxwell's equations. The work comprises five publications written by the author. Three of these publications focus on describing light propagation within turbid media, comparing radiative transfer theory with classical electromagnetic theory to examine their differences. The remaining two publications address the numerical simulation of phase-optimized light beams within scattering media, aiming to restore a focus of light deep within the medium. Additionally, the thesis includes an introductory section that outlines the motivation behind the research, describes the relevant theories, and provides a summary of each publication. Furthermore, a conclusion and an outlook for future research directions are presented
Optimal traffic light control: performance evaluation applying a general evaluation methodology
No full textThe ongoing increase in urbanization and traffic congestion creates an urgent need to operate our transportation systems with maximum efficiency. Traffic signal control optimization is considered one of the main ways to solve traffic problems in urban networks. In publications in the field of intelligent transportation systems, a vast amount of different optimal trafficlight control methods is described. With new optimization methods being developed, it is important to know their performance compared to similar methods. Such a comparison is only possible if the same performance evaluation methodology is applied to all these methods. Most of the studies in the field of intelligent transportation system consider a self-defined evaluation methodology. A general evaluation methodology is developed to objectively evaluate the performance of these optimization methods. The developed general evaluation methodology is used to evaluate the performance of a dynamic programming and Q-learning method
Topology Optimization of Wave Barriers: Development of a tool for use in engineering practice
No full textWave barriers are a common mitigation measure when dealing with environmentally induced vibrations. These wave barriers generally consist of stiff vertical walls buried in the soil to impede waves on their path from the source to the receiver. The geometries of the wave barriers that are used in practice are very simple. More complex geometries have not often been considered as it is difficult to estimate which changes would increase the effectiveness.In literature, topology optimization was explored as a method to design wave barriers. This method was applied while modelling the soil as a homogeneous elastic half-space. The resulting wave barriers showed a significant increase in the achieved vibration reduction. However, the designs were often very complex and hard to manufacture. In this thesis the method was improved by introducing a layered soil and by ensuring the manufacturability of the designed wave barriers.The improved method was then applied to multiple situations in order to investigate aspects of wave barrier design and effectiveness. Optimization of a wave barrier for a two-layered soil model showed the significance of implementing a layered soil model. The interface between two layers resulted in reflections that could diminish the effectiveness of a wave barrier if not accounted for. The optimization algorithm responded to these reflections by placing material in the path of waves that would otherwise reflect back to the surface. A wave barrier optimized for a three-layered soil model that consisted of a softer layer embedded in a stiff layer and a stiff half-space showed a different approach to reflections. The wave barrier appeared to use the softer layer as a waveguide in order to reduce the energy at the surface.The manufacturability was increased by adding constraints. This resulted in wave barriers with a more manufacturable design at the cost of a decrease in vibration reduction. In three of the four cases, the optimized wave barrier still performed significantly better than the reference wave barrier. In one case, the final design reverted back to the reference wave barrier when the manufacturability conditions were applied.The goals set at the start of the thesis were largely accomplished. The model was able to more accurately reflect soil profiles found in practice by using a layered soil model and the topology optimization algorithm resulted in wave barriers that are relatively easy to manufacture while still showing a significant improvement over the standard reference wave barriers. The possible use ofsoft embedded layers as waveguides was discovered during the optimization. Future research into this possibility could prove valuable. Some concerns are posited with regards to the reliability of the wave barriers. In some cases, the optimized wave barrier appeared to abuse the idealized representation of the interface between layers. An initial investigation showed that in those cases,the effectiveness of the wave barrier was sensitive to changes of the interface depth. Further investigation would be required to determine the sensitivity of the designed wave barriers to other parameters related to the idealized representations of the interfaces.<br/
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