Cette thèse est la R&D de l’électronique de front-end destinée à la camera de deuxième génération du télescope de grande taille LST de projet CTA, étant basée sur les détecteurs de type SiPM. Cette étude rassemble des équipes du LAPP, de l’université de Padoue, de l’INFN et du MPI de Munich. La première partie de cette thèse porte sur les tests de caractérisations d’une matrice de 16 SiPMs fabriquée par Hamamatsu. Les résultats de ces tests ont souligné les avantages qui pourraient être apportés par l’utilisation de tels détecteurs. Un cahier des charges pour l’électronique a été défini à l’issue de ces tests. Notamment, une nécessité de corriger la dispersion en gain entre les 16 pixels qui a été trouvée d’environ 10%. La seconde partie est la conception d’un circuit intégré (ASIC) qui pourrait lire les signaux des pixels -SiPM avec la moindre perturbation possible de fonctionnement du détecteur. Cet ASIC inclut des fonctions de contrôle (slow control) qui permettent l’ajustement de gain des pixels, l’amélioration de l’uniformité de gain et la possibilité de supprimer les canaux bruyants ou encore même le contournement du processus de contrôle de gain. Ces fonctionnalités peuvent unifier le gain de 16 canaux. Les sorties des 16 canaux seront sommées pour en faire deux signaux seulement à la sortie de l’ASIC. Ces deux signaux, un sur le haut gain et l’autre sur le bas gain seront fournis au système d’acquisition qui suivra l’ASIC. Une fonction de déclenchement génèrera un signal de trigger qui sera ainsi transmis au système d’acquisition. Cet ASIC a été réalisée avec la technologie AMS 0.35um BiCMOS. Les simulations ont montré une gamme dynamique linéairement couverte jusqu’à 2000 photoélectrons et la possibilité de mesurer le photoélectron unique grâce au bon rapport signal sur bruit électronique. Les tests au laboratoire confirment une grande partie de ces résultats. / This thesis is the R&D on front-end electronics for a second generation camera based on the SiPM detectors for the Large Size Telescope (LST) of the CTA project. It is a part of the SiPM collaboration involving the LAPP, the University of Padua, the INFN and the MPI in Munich. The first part of the thesis is the characterization of an array of 16 SiPMs from Hamamatsu. The study proves the advantages of using such detectors in the LST. It defines the specifications of the readout electronics that are the aim of this work. Especially that it should ameliorate the gain dispersion of the 16 pixels that was found of about 10%. The second part is the design of the readout ASIC. The scheme tends to measure the SiPMs’ signals with minimum disturbance of the detector. It integrates slow control facilities that adjust the detector’s gain, minimize the dispersion in gain and provide the possibility of deleting noisy channels or even completely jumping over the control process. These facilities could perfectly get rid of the gain dispersion. Outputs of the 16 pixels will be summed on both high gain and low gain so that only two signals are delivered to the acquisition system that follows. A trigger function will also generate a trigger signal to the acquisition system. The choice was made to realize this ASIC according to the rules of the AMS 0.35um BiCMOS technology. Simulation shows a linearly-covered dynamic range up to 2000 photoelectrons with good signal to noise ratio that allows the measurement of the single photoelectron. Laboratory tests confirm a great part of these results.

Ziel dieser Diplomarbeit ist die Untersuchung der Auswirkungen des vollautomatischen Bahnbetriebs (GoA 4/UTO) auf ETCS und weitere ZZS-Umsysteme. Dafür werden die verschiedenen Rahmenbedingungen systematisch untersucht. Es werden Basisfunktionen und Umsysteme aufgestellt, um den GoA 4-Betrieb zu beschreiben. Es wird gezeigt, dass der GoA 4-Betrieb zum aktuellen Zeitpunkt in Deutschland nicht rechtssicher durchführbar ist und die aktuellen betrieblichen Regelwerke nicht geeignet sind. Die Arbeit kommt zu dem Schluss, dass ETCS für den GoA 4-Betrieb geeignet und eine Weiterentwicklung der Spezifikation angebracht ist. Es entstehen neue Schnittstellen. Ein Vergleich der Automatisierungsgrade offenbart teils deutliche systemische Unterschiede. Die Fernsteuerung der Fahrzeuge und Fahrzeugbedienungen ist ein elementares System zur Anwendung in der Rückfallebene in niedrigeren Automatisierungsgraden. Insgesamt besteht ein hoher Anpassungsaufwand gegenüber den aktuell gültigen Anforderungen, was sich z. B. durch signifikant höhere Konnektivitätsanforderungen zeigt.:1 Einleitung 2 Rahmenbedingungen des vollautomatischen Bahnbetriebs 3 Funktionen und Umsysteme des vollautomatischen Bahnbetriebs 4 Einfluss des vollautomatischen Bahnbetriebs auf ETCS 5 Systemische Unterschiede der Automatisierungsgrade 6 Vertiefte Betrachtung ausgewählter Aspekte 7 Zusammenfassung und Ausblick / The objective of this diploma thesis is to analyse the effects of fully automatic rail operations (GoA 4/UTO) on ETCS and further CCS systems. For this purpose, the various framework conditions are systematically investigated. Basic functions and further systems are defined in order to describe UTO. It is shown that UTO is not legally feasible in Germany at present and that the current operational regulations are not suitable. This thesis concludes that ETCS is suitable for application in GoA 4 and that the further development of the specification is reasonable. New interfaces are emerging. A comparison between the grades of automation partly reveals significant systemic differences. The remote control of vehicles and vehicle operations is a fundamental system for use in the fall-back level at lower grades of automation. Overall, there is a high need for adjustments compared to the currently existing requirements, which is shown, e. g., by significantly higher connectivity requirements.:1 Einleitung 2 Rahmenbedingungen des vollautomatischen Bahnbetriebs 3 Funktionen und Umsysteme des vollautomatischen Bahnbetriebs 4 Einfluss des vollautomatischen Bahnbetriebs auf ETCS 5 Systemische Unterschiede der Automatisierungsgrade 6 Vertiefte Betrachtung ausgewählter Aspekte 7 Zusammenfassung und Ausblick

Zur Errichtung und Inbetriebnahme von Anlagen der Leit- und Sicherungstechnik (LST), zu denen beispielsweise Elektronische Stellwerke (ESTW) gehören, sind unter anderem definierte Planungs-, Begutachtungs- und Freigabeschritte zu durchlaufen. Die vorliegende Arbeit thematisiert den LST-Planungsprozess hinsichtlich seiner erforderlichen Abläufe und Komplexität im Vergleich der bisherigen Regelwerksvorgaben mit praktischen Umsetzungen. Auf den Analyseergebnissen einschließlich herausgearbeiteter Probleme aufbauend, werden unter Berücksichtigung aktueller Erkenntnisse aus dem Forschungsprojekt „PlanPro - Durchgängige elektronische Datenhaltung im ESTW-Planungsprozess“ Vorschläge für einen zukünftigen LST-Planungsprozess vorgestellt und wissenschaftlich aufbereitet. Dabei sollen durch den verstärkten Einsatz IT-gestützter Verfahren die Planungsqualität erhöht und die Prozesse insgesamt beschleunigt werden. In der Arbeit werden auch grundlegende Neuerungen mit PlanPro dargestellt, ebenso wie Anforderungen an die LST-Datenbank, die zukünftig eine zentrale Rolle für das Abspeichern und Weitergeben von Planungs- und Bestandsdaten einnehmen wird. Erläuterungen zu einem denkbaren Einführungskonzept sowie eine Schlussbetrachtung runden diese Dissertation ab. / For installation and commissioning of railway signalling equipment, which may include computer-based interlocking (CBI), defined tasks for planning, assess-ment and approval have to be executed. This dissertation analyses the planning process of the railway signalling equipment with regard to its necessary processes and complexity. Additionally, it compares existing legal requirements with their practical realisation. Based on the results of this analysis and their identified problems, proposals for a future planning process for railway signalling equipment will be scientifically prepared and presented. They are taking into account the latest results from the research project "PlanPro - Integrated electronic data storage in electronic interlocking planning process". By the progressive use of IT-based processes, planning quality will be increased and the processes can be accelerated altogether. Thereupon, fundamental changes based on PlanPro are presented. This applies to requirements for the database of railways signalling equipment, which will play a key role for the storage and sharing of planning and inventory data in the future, too. An explanation of a possible introduction concept as well as a conclusion complete this disserta-tion.

Land surface temperature (LST) and mean radiant temperature (MRT) are commonly used as proxies to evaluate urban heat environments. Many scholars use one of them to represent heat exposure when assessing the urban thermal environment. This research fills a research gap by analyzing two meteorological parameters simultaneously through correlation analysis, hotspot analysis, and the distinctive information they respectively express with the results of vulnerable population distribution based on the case of Linköping. Scatter plots are used to explore the correlation between LST and MRT, and hot spot analysis is applied to investigate their spatial patterns through the clusters of hot and cold spots. Furthermore, the distribution of vulnerable populations is assessed and visualized through a vulnerability index. The results show that there is a moderate positive linear correlation between the mean values of LST and MRT for the whole study area. They have different spatial patterns based on the results of the hot spot analysis. The comparison of different meteorological parameters to the vulnerability index also shows variations in high heat risk areas. All of these conclude that LST or MRT could, to some extent, be presented as references to each other; however, they cannot be used interchangeably as proxies for urban heat exposure. When developing urban thermal adaptation strategies, it is necessary for municipalities to select the parameters appropriately according to the purpose and requirements and to understand what the chosen parameters can and cannot convey.

This dissertation presents a liquidity stress-testing model for evaluating liquidity and systemic risk in banks from developed and emerging economies respectively. The model further relies on simulations to generate liquidity buffer losses for both a non-crisis and crisis period as well. The emerging economy is represented by South Africa (SA) and the developed economy by the United Kingdom (henceforth UK). The Liquidity Stress Tester model (LST) has been successfully applied to both the Dutch and UK markets in previous research. The model's flexibility and adaptability allows it to assess different banking systems and different reactions (buffer restoration and leverage targeting) of participants within these milieus. The LST considers feedback effects arising from bank reactions and allows for the assessment of severely stressed haircuts and systemic risk increases caused by reputation degradation and increased contagion from other banks. Losses stemming from the second round effects of a liquidity event are explored through the reactions conducted by banks in the banking system. The study conducts a review of liquidity risk models utilised in previous research. Characteristics of these models and the data they used are highlighted, shedding light on the advantages and shortcomings of these models. Possible restrictions in liquidity risk management are also explored. The study discusses the relevance of the South African/UK economies' comparison, as well as the selected periods chosen for investigation. To assist further research with the LST, the study illustrates and discusses how it is modelled and developed in Microsoft Office Excel. The results obtained illustrate the potential severity of second round feedback effects of a liquidity event on liquidity positions in banks. The effects of mitigating actions conducted by banking institutions reacting to initial liquidity stress shocks are explored, as well as the way these actions could potentially affect second round effects on banks. The analysis and discussion of simulated results attempts to isolate and identify characteristics of economies and periods used that may have contributed to specific liquidity events. The study concludes with a summary of the research and suggestions for possible future work and development using the LST. / MCom (Risk Management), North-West University, Potchefstroom Campus, 2013

This dissertation presents a liquidity stress-testing model for evaluating liquidity and systemic risk in banks from developed and emerging economies respectively. The model further relies on simulations to generate liquidity buffer losses for both a non-crisis and crisis period as well. The emerging economy is represented by South Africa (SA) and the developed economy by the United Kingdom (henceforth UK). The Liquidity Stress Tester model (LST) has been successfully applied to both the Dutch and UK markets in previous research. The model's flexibility and adaptability allows it to assess different banking systems and different reactions (buffer restoration and leverage targeting) of participants within these milieus. The LST considers feedback effects arising from bank reactions and allows for the assessment of severely stressed haircuts and systemic risk increases caused by reputation degradation and increased contagion from other banks. Losses stemming from the second round effects of a liquidity event are explored through the reactions conducted by banks in the banking system. The study conducts a review of liquidity risk models utilised in previous research. Characteristics of these models and the data they used are highlighted, shedding light on the advantages and shortcomings of these models. Possible restrictions in liquidity risk management are also explored. The study discusses the relevance of the South African/UK economies' comparison, as well as the selected periods chosen for investigation. To assist further research with the LST, the study illustrates and discusses how it is modelled and developed in Microsoft Office Excel. The results obtained illustrate the potential severity of second round feedback effects of a liquidity event on liquidity positions in banks. The effects of mitigating actions conducted by banking institutions reacting to initial liquidity stress shocks are explored, as well as the way these actions could potentially affect second round effects on banks. The analysis and discussion of simulated results attempts to isolate and identify characteristics of economies and periods used that may have contributed to specific liquidity events. The study concludes with a summary of the research and suggestions for possible future work and development using the LST. / MCom (Risk Management), North-West University, Potchefstroom Campus, 2013

The major aim of this work is to develop a framework for the estimation of Evapotranspiration (ET) over the Indian landmass using remote sensing (RS) datasets in a repeated and consistent manner with improved spatial resolution. Different RS based ET models exist in the literature, out of which, the triangle, the S-SEBI and the Sim-ReSET models were compared for the estimation of daytime integrated latent heat flux (λEday). These three models were chosen as they can be driven only with RS based inputs without the need for any ground measurements. The results showed that the application of simpler contextual models may yield better results than physically based models when ground data is limited or not available. To improve the spatial resolution of one of the key surface variable, Land Surface Temperature (LST), the performance of five different vegetation indices Normalised Difference Vegetation Index (NDVI), Fraction Vegetation Cover (FVC), Normalised Difference Water Index (NDWI), Soil Adjusted Vegetation Index (SAVI) and Modified SAVI (MSAVI) were tested in the existing DisTrad disaggregation model. Results suggested that the most commonly used vegetation indices NDVI and FVC yielded better results only under wet conditions. Under drier surface conditions, using NDWI for disaggregation resulted in relatively higher accurate LST. A model for spatial disaggregation of Evaporative Fraction (EF) called DEFrac (Disaggregation of Evaporative Fraction) was developed based on the relationship between EF and NDVI to obtain finer spatial resolution EF from coarser resolution estimates. The experimental results suggested that the DEFrac model developed in this study, yielded more accurate disaggregated EF. The disaggregated EF was further used to get disaggregated λEday. Finally, The issue of lack of proper ET dataset over India was addressed by developing two data products one over entire India at 0.05° spatial resolution and the second product over the Kabini basin at 1 km spatial resolution. Both the products were developed with a temporal resolution of 8-day and for the period 2001–2014. The developed ET products were validated against ground observed data at seven sites across India and against ET simulated by a hydrological model over a forested watershed. Further the developed ET products were compared with some other global ET products such as MOD16, LandFlux Eval synthesis ET and GLEAM ET. Analyses revealed that only in regions where ET is predominantly driven by rainfall and where irrigation is not applied at very large scales, the global ET products tend to capture the ET patterns satisfactorily. On the other hand, the ET products developed in this work captured the spatial and temporal patterns of ET quite realistically all across India.

Zur Errichtung und Inbetriebnahme von Anlagen der Leit- und Sicherungstechnik (LST), zu denen beispielsweise Elektronische Stellwerke (ESTW) gehören, sind unter anderem definierte Planungs-, Begutachtungs- und Freigabeschritte zu durchlaufen. Die vorliegende Arbeit thematisiert den LST-Planungsprozess hinsichtlich seiner erforderlichen Abläufe und Komplexität im Vergleich der bisherigen Regelwerksvorgaben mit praktischen Umsetzungen. Auf den Analyseergebnissen einschließlich herausgearbeiteter Probleme aufbauend, werden unter Berücksichtigung aktueller Erkenntnisse aus dem Forschungsprojekt „PlanPro - Durchgängige elektronische Datenhaltung im ESTW-Planungsprozess“ Vorschläge für einen zukünftigen LST-Planungsprozess vorgestellt und wissenschaftlich aufbereitet. Dabei sollen durch den verstärkten Einsatz IT-gestützter Verfahren die Planungsqualität erhöht und die Prozesse insgesamt beschleunigt werden. In der Arbeit werden auch grundlegende Neuerungen mit PlanPro dargestellt, ebenso wie Anforderungen an die LST-Datenbank, die zukünftig eine zentrale Rolle für das Abspeichern und Weitergeben von Planungs- und Bestandsdaten einnehmen wird. Erläuterungen zu einem denkbaren Einführungskonzept sowie eine Schlussbetrachtung runden diese Dissertation ab. / For installation and commissioning of railway signalling equipment, which may include computer-based interlocking (CBI), defined tasks for planning, assess-ment and approval have to be executed. This dissertation analyses the planning process of the railway signalling equipment with regard to its necessary processes and complexity. Additionally, it compares existing legal requirements with their practical realisation. Based on the results of this analysis and their identified problems, proposals for a future planning process for railway signalling equipment will be scientifically prepared and presented. They are taking into account the latest results from the research project "PlanPro - Integrated electronic data storage in electronic interlocking planning process". By the progressive use of IT-based processes, planning quality will be increased and the processes can be accelerated altogether. Thereupon, fundamental changes based on PlanPro are presented. This applies to requirements for the database of railways signalling equipment, which will play a key role for the storage and sharing of planning and inventory data in the future, too. An explanation of a possible introduction concept as well as a conclusion complete this disserta-tion.

Urbanization modifies the thermal characteristics of the land and makes way for a succession of transformations in the urban environmental system. This phenomenon, known as Urban Heat Island (UHI), is characterized by elevated temperatures in urban areas that negatively impact on the quality of life and environment in urban areas including, increased emissions of Green House Gases (GHGs) and rising energy consumption. These impacts add to global climate change and thus, mitigating UHI is essential to mitigating global climate change. One GHG, Carbon Dioxide (CO2), accounts for about half of the Earth’s anthropogenic GHG emissions. Terrestrial ecosystems can act as Carbon sinks (C sinks), i.e. natural vegetation reservoirs that absorb more C than they release. Thus, C sinks play an essential and critical function in lowering CO2. Furthermore, providing appropriate C sinks at both the building and urban scales can decrease UHI and contribute to reduction in energy consumption. This study used Landsat 8 imagery of the site, Al Bayt Stadium in Qatar, to investigate the effects of surface UHI by computing the Land Surface Temperature (LST) difference of the site---pre- and post-construction, as well as examine the correlation between natural vegetation abundance and temperature in ten locations within the site’s vicinity. Results show that minimum, maximum and mean LST of the case study area (2014 vs. 2020) decreased 2.80 oC, 5.5 oC and 2.3 oC, respectively, as well as a decreasing trend in the LST as a function of increasing C Sinks. These results demonstrate the importance of introducing C sinks to lower LST and mitigate UHI. Mitigating UHI also has a direct effect on Energy Consumption Balance (ECB). This equilibrium is achieved not only through the introduction of C sinks, but balancing C sinks with high albedo materials and natural ventilation.  Thus, this study also investigated the site’s various design aspects (e.g. cooling technology, structure and surface albedo materials, landscaping) and found that Al Bayt Stadium’s design successfully incorporates strategies to reduce energy consumption at both the urban (macro) and building (micro) scales.

Sowohl auf nationaler als auch internationaler Ebene sind bei elektronischen Stellwerken der ersten Generation die Schnittstellen zwischen den Bestandteilen der Leit- und Sicherungstechnik (LST) überwiegend herstellerspezifisch gestaltet. Das EULYNX-Konsortium befasst sich in Europa aus diesem Grund mit der Spezifizierung von standardisierten Schnittstellen im Bereich der LST. Die wesentlichen Ziele, welche es unter der Nutzung von konventioneller Netzwerktechnik und durch eine Entkopplung der Anlagenbestandteile zu erreichen gilt, sind das Fördern des Wettbewerbs zwischen der Signalbauindustrie, das Reduzieren der Lebenszykluskosten und das Verhindern der Obsoleszenz. Die Professur für Verkehrssicherungstechnik strebt für eine aktive Beteiligung an der Weiterentwicklung von standardisierten Schnittstellen den Aufbau von EULYNX-Versuchsständen an. Dazu betrachtet diese Masterarbeit die Hochrüstung der im Sicherungstechnischen Labor vorhandenen Bahnübergangssicherungsanlage (BÜSA) BUES 2000 auf eine EULYNX-Schnittstelle und analysiert verschiedene Varianten zur Gestaltung einer umgebenden Laboranlage sowie eines Versuchsstandes. Ein weiterer Forschungsgegenstand ist dabei die Recherche der erforderlichen Voraussetzungen zur Nutzung der konzipierten Laboranlage für Validierungsaufgaben. Den Abschluss dieser Ausarbeitung bildet ein Testkonzept, welches in der Form von Testspezifikationen sowohl für die Integration als auch die Validierung des Versuchsstandes verwendet werden kann.