No / Abstract: Avoiding collision among contending customer premise equipments (CPEs) attempting to associate with a base station (BS), the only available solution in IEEE 802.22 standard is binary exponential random backoff process in which the contending CPEs retransmit their association requests. The number of attempts the CPEs sends their requests to the BS are fixed in IEEE 802.22 network. This paper presents a mathematical framework for helping the BS in determining at which attempt the majority of the CPEs become the part of wireless regional area network (WRAN) from a particular number of contending CPEs at a given initial contention window size.

Ce travail de thèse a pour but de mieux documenter les processus majeurs qui ont lieu lors de la collision alpine : le raccourcissement crustal, l'évolution thermique et les circulations de fluides. La première partie de ce travail apporte de nouvelles données thermo-chronologiques U-Th-Sm/He sur zircon (ZHe) et RSCM (Raman Spectroscopy on Carbonaceous Material, Tmax) sur le massif des Aiguilles Rouges. Ces données sont intégrées à l'histoire thermique de ces massifs et utilisées pour contraindre l'évolution structurale de la marge dauphinoise proximale lors de son inversion. La seconde partie de ce travail consiste en la mise au point d'une nouvelle méthode de restauration des coupes qui ont subi de fortes déformations ductiles. Le travail de terrain a de plus permis de définir le cadre structural et microstructural de l'étude des circulations de fluides à l'interface entre socle et couverture dans ces mêmes bassins du massif de l'Oisans. Les données géochimiques (isotopie, microthermométrie des inclusions fluides, éléments traces) montrent que des fluides (en faible quantité) dérivés du socle ont percolé à la base de la couverture dès l'initiation du raccourcissement collisionnel. Ces résultats permettent de proposer un modèle conceptuel d'évolution des circulations de fluides à l'échelle des massifs cristallins externes alpins. Dans une dernière partie, la modélisation thermomécanique de l'inversion de bassins hérités montre que la profondeur d'enfouissement tectonique joue un rôle primordial dans le style d'inversion des bassins. L'ensemble des résultats sont intégrés dans un modèle d'inversion collisionnelle de la marge européenne. / This work aims at better documenting and understanding major processes that occur during Alpine collision, such as crustal shortening, thermal evolution and fluid circulations. In the first part of the work, we provide new U-Th-Sm/He on zircon (ZHe) thermochronological data and new RSCM (Raman Spectroscopy on Carbonaceous Material) data for the Aiguilles Rouges. These data are integrated into the thermal histories of these massifs and used to constrain the structural evolution of the proximal Dauphinois margin during its collisional inversion. The second part of the work consists of the development of a new methodology to balance cross-sections where rocks were ductilely deformed. Finite deformation of the metasedimentary cover of the Oisans basins is used to constrain shortening. Fieldwork allowed us to define the structural and microstructural setting for the study of fluid circulations close to the basement/cover interface in the very same basins. Geochemical analyses (stable isotopes, microthermometry of fluid inclusions and trace elements) highlight that small amount of basement-derived fluids percolated into the cover as soon as the onset of collisional shortening. Those results are gathered into a conceptual model of evolution of fluid circulation through time and progressive deformation at the scale of the entire ECM. In the last part, thermomechanical modeling of inversion of inherited extensional basins show that tectonic burial is a major parameter controlling basin inversion style. Finally, all those new results are integrated into a scenario of the inversion of the European margin during Alpine collision.

La plupart des activités humaines, industrielles ou domestiques, requièrent aujourd’hui l’utilisation d’énergie électrique. Les choix faits pour la production de cette électricité ont nécessité le développement de réseaux de transport d’électricité. En raison de sa densité de câbles, ce réseau induit une fragmentation de l’habitat des animaux volants et principalement des oiseaux. Au-delà des électrocutions au niveau des pylônes, cette fragmentation peut causer la mort d’individus par collision avec les câbles (Bevanger, 1998; Jenkins et al., 2010) et également le dérangement des espèces ou des modifications de leur comportement (Deng and Frederick, 2001; Prinsen et al., 2011; Shimada, 2001). Un grand nombre de facteurs influençant les collisions sont aujourd’hui identifiés (Janss, 2000; Martin and Shaw, 2010). Cependant, la quantification de la mortalité par collision reste complexe en raison de l’hétérogénéité des méthodes utilisées et de l’existence de biais à la quantification (Bech et al., 2012; Ponce et al., 2010). Cette thèse se concentre sur une approche méthodologique de l’étude des interactions des oiseaux avec le réseau de lignes électriques haute-tension (HT) et très-haute-tension (THT) en France métropolitaine. Le premier volet de la thèse concerne la localisation et la hiérarchisation de zones à risque d’interaction pour les oiseaux sur l’ensemble du réseau. Dans ce but, des données de configuration des lignes électriques, de présence (atlas) et de déplacement (couloirs de migration) d’espèces d’oiseaux vulnérables aux lignes électriques sont combinées. Le deuxième volet de la thèse consiste à mettre au point des méthodes qui pourraient permettre de quantifier à l’échelle nationale la mortalité des oiseaux par collision avec les lignes électriques HT-THT. La méthodologie proposée se base sur l’estimation des biais à la quantification, réalisée au cours de la thèse, que sont la détection des cadavres d’oiseaux par les observateurs et la persistance des cadavres sous les lignes électriques. Le troisième et dernier volet de la thèse concerne les modifications de comportement des oiseaux en réponse à la fragmentation de l’espace aérien. Afin de caractériser les mouvements des oiseaux à l’approche des lignes électriques, nous avons adapté une méthodologie d’analyse proposée récemment pour étudier les stratégies d’évitement des oiseaux à différentes échelles spatiales. L’objectif de cette analyse est d’identifier les comportements de vol qui pourraient résulter en une collision avec les câbles. Des données de suivis par télémétrie en trois dimensions (données GPS 3D) de Vautour fauve (Gyps fulvus) sont utilisées dans cette étude comportementale. Ce travail de recherche a permis de proposer un cadre méthodologique pour l’étude des interactions entre oiseaux et lignes électriques et de mettre en évidence l’importance des biais de quantification associés à la recherche de cadavres d’oiseaux sous les lignes. Il a établi pour la première fois une hiérarchisation du risque d’interaction des oiseaux avec les lignes électriques sur l’ensemble du réseau de transport d’électricité français. Les facteurs qui influencent l’utilisation de l’espace à proximité des lignes électriques par les vautours fauves dans les Causses ont également été mis en évidence. / Nowadays, most human activities, be they industrial or domestic, involve the use of electricity. Electricity production choices have required the development of electricity transmission networks. The density of this network has fragmented the habitats of flying animals, birds mainly. Further to the electrocution at power poles, this fragmentation can also cause the death of birds colliding with power lines (Bevanger, 1998; Jenkins et al., 2010) and also the disturbance of species or changes in their behaviour (Deng and Frederick, 2001; Prinsen et al., 2011; Shimada, 2001). Many factors have been identified that influence collision (Janss, 2000; Martin and Shaw, 2010). However, bird mortality by collision is difficult to quantify because of the heterogeneity of methods used and also of the existence of quantification biases (Bech et al., 2012; Ponce et al., 2010). This work is centered on a methodological analysis of the interactions between birds and the High-Voltage(HV) and the Very-High-Voltage (VHV) power grid in Metropolitan France. The First Part discusses the localisation and proposes a hierarchy of the risk areas for birds all along the power network. To this purpose we combine data on the configuration of the power network with data on the presence (breeding atlas), and the movements (migration corridors) of bird species that are vulnerable to power lines. In the Second Part, we developed methods for the quantification, at the national level, of bird mortality that result from the collision with HV and VHV power lines. The methodology proposed builds on the estimation achieved during this thesis of the quantification biases through bird carcass detection by observers and the persistence of these carcasses below power lines. The third and last part of this thesis is about bird behaviour change as a response to airspace fragmentation. We characterised the behaviour of birds when they come close to power lines, by adapting a methodology that analyses bird movements. This methodology was recently proposed for the study of bird avoidance at different spatial scales. The aim of our analysis was to identify flight behavior that potentially results in a collision with power lines. Griffon vultures (Gyps fulvus) data collected with three dimensional telemetry (3D GPS data) were used in this behavioural study. This research corpus brings forward a methodological framework for the study of the interaction between birds and power lines and highlights the magnitude of quantification biases associated to the search for bird remains below power lines. For the first time a hierarchy of interactions risks between birds and power lines is established across the entire electricity transmission network in France. Factors that influence Griffon vultures spatial use in the vicinity of power lines in the French Causses were identified.

<p>A CMbB system is a system that with the help of sensors in the front of a car detects when a collision in unavoidable. When a situation like that is detected, the brakes are activated. The decision of whether to activate the brakes or not is taken by a piece of software called a decision maker. This software continuously checks for routes that would avoid an object in front of the car and as long as a path is found nothing is done. Volvo has been investigating several different CMbB-systems, and the research done by Volvo has previously focused on decision makers that only consider one object in front of the car. By instead taking all present objects in consideration, it should be possible to detect an imminent collision earlier. Volvo has developed some prototypes but needed help evaluating their performance. </p><p>As part of this thesis a testing method was developed. The idea was to test as many cases as possible but as the objects’ possible states increase, the number of test cases quickly becomes huge. Different ways of removing irrelevant test cases were developed and when these ideas were realized in a test bench, it showed that about 98 % of the test cases could be removed. </p><p>The test results showed that there is clearly an advantage to consider many objects if the cost of increased complexity in the decision maker is not too big. However, the risk of false alarms is high with the current decision makers and several possible improvements have therefore been suggested.</p>

A CMbB system is a system that with the help of sensors in the front of a car detects when a collision in unavoidable. When a situation like that is detected, the brakes are activated. The decision of whether to activate the brakes or not is taken by a piece of software called a decision maker. This software continuously checks for routes that would avoid an object in front of the car and as long as a path is found nothing is done. Volvo has been investigating several different CMbB-systems, and the research done by Volvo has previously focused on decision makers that only consider one object in front of the car. By instead taking all present objects in consideration, it should be possible to detect an imminent collision earlier. Volvo has developed some prototypes but needed help evaluating their performance. As part of this thesis a testing method was developed. The idea was to test as many cases as possible but as the objects’ possible states increase, the number of test cases quickly becomes huge. Different ways of removing irrelevant test cases were developed and when these ideas were realized in a test bench, it showed that about 98 % of the test cases could be removed. The test results showed that there is clearly an advantage to consider many objects if the cost of increased complexity in the decision maker is not too big. However, the risk of false alarms is high with the current decision makers and several possible improvements have therefore been suggested.

Historically, the traditional planning process has not given much attention to the road safety evaluation of development plans. To make an informed, defensible, and proactive choice between alternative plans and their safety implications, it is necessary to have a procedure for estimating and evaluating safety performance. A procedure is required for examining the influence of the urban network development on road safety, and in particular, determining the effects of the many variables that affect safety in urban planning. Safety planning models can provide a decision-support tool that facilitates the assessment of the safety implications of alternative network plans. The first objective of this research study is to develop safety planning models that are consistent with the regional models commonly used for urban transportation planning. Geographically weighted Poisson regression (GWPR), full-Bayesian semiparametric additive (FBSA), and traditional generalized linear modelling (GLM) techniques are used to develop the models. The study evaluates how well each model is able to handle spatial variations in the relationship between collision explanatory variables and the number of collisions in a zone. The evaluation uses measures of goodness of fit (GOF) and finds that the GWPR and FBSA models perform much better than the conventional GLM approach. There is little difference between the GOF values for the FBSA and GWPR models. The second objective of this research study is to examine the temporal transferability of the safety planning models and alternative updating methods. The updating procedures examine the Bayesian approach and application of calibration factors. The results show that the models are not temporally transferable in a strict statistical sense. However, relative measures of transferability indicate that the transferred models yield useful information in the application context. The results also show that the updated safety planning models using the Bayesian approach predict the number of collisions better than the calibration factor procedure.

Historically, the traditional planning process has not given much attention to the road safety evaluation of development plans. To make an informed, defensible, and proactive choice between alternative plans and their safety implications, it is necessary to have a procedure for estimating and evaluating safety performance. A procedure is required for examining the influence of the urban network development on road safety, and in particular, determining the effects of the many variables that affect safety in urban planning. Safety planning models can provide a decision-support tool that facilitates the assessment of the safety implications of alternative network plans. The first objective of this research study is to develop safety planning models that are consistent with the regional models commonly used for urban transportation planning. Geographically weighted Poisson regression (GWPR), full-Bayesian semiparametric additive (FBSA), and traditional generalized linear modelling (GLM) techniques are used to develop the models. The study evaluates how well each model is able to handle spatial variations in the relationship between collision explanatory variables and the number of collisions in a zone. The evaluation uses measures of goodness of fit (GOF) and finds that the GWPR and FBSA models perform much better than the conventional GLM approach. There is little difference between the GOF values for the FBSA and GWPR models. The second objective of this research study is to examine the temporal transferability of the safety planning models and alternative updating methods. The updating procedures examine the Bayesian approach and application of calibration factors. The results show that the models are not temporally transferable in a strict statistical sense. However, relative measures of transferability indicate that the transferred models yield useful information in the application context. The results also show that the updated safety planning models using the Bayesian approach predict the number of collisions better than the calibration factor procedure.

Spray drying is a process, which produces powders from the fluid state. This type of process is mostly used in the industrial sector. In this process, a liquid slurry is atomized, forming droplets, which are dried with hot air. During spray drying these droplets will interact and upon impact can show different types of interactions; droplet-droplet collisions as well as interactions with partially or completely dried particles, leading to agglomeration. The result of collision gives properties of the dried powder. The focus of the thesis is to investigate the droplet-droplet collision outcomes of WPC 80 (Whey Protein Concentrate 80) and Lactose. Then the effects of the absolute droplet diameter and the droplet diameter ratios are to be determined. Existing experimental setup and Image Processing Tool of MATLAB is used to study the collision outcome. The outcomes are shown in a regime map. The present results are compared with different products result and literature study. It is observed that there is an effect on collision outcome for different droplet size ratios and no effect for absolute droplet diameter.

This thesis describes methods for collision detection and collision response, implemented in a complete collision framework for both rigid and deformable bodies. The framework is intended to act as a base for new technologies regarding muscle and facial simulation for feature film production, at the visual effects studio MPC. Specifically, we implement sweep and prune as a first step in our collision detection for fast pruning of pairs, followed by optimized spatial hashing to decrease the amount of triangle intersection tests. Further, we use a constraint-based method for collision response based on iterative constraint anticipation, which provides several advantages in terms of accuracy compared to penalty- or impulse-based methods.

En 1957, la conquête de l'espace par l'homme commença avec le succès de la mise en orbite du premier satellite artificiel ; Spoutnik 1. Ce fut le début de l'exploitation de l'orbite terrestre caractérisée par une centaine de lancements de fusées partant de Kourou, Baïkonour et autres bases de lancement. Aujourd'hui, l'orbite terrestre a une population composée en majeure partie de débris spatiaux. Ces derniers regroupent des étages supérieurs de fusée, des satellites ayant fini leur mission et autre petits objets artificiels dont l'origine n'est pas forcément identifiable. Leur nombre est devenu si important, allant même jusqu'à remettre en cause la viabilité des activités spatiales que leur étude est devenu incontournable. La génération de nouveaux débris se traduit majoritairement par l'avènement d'une collision ou d'une explosion. Une meilleure connaissance de ces évènements dits évènements de fragmentation permettra une meilleure lutte contre la prolifération des débris spatiaux. Afin d'optimiser l'étude d'un nuage de débris, il est nécessaire de développer de nouveaux outils. Dans la première partie de la thèse, nous élaborons un modèle de fragmentation permettant de créer des nuages de débris spatiaux générés à la suite d'une explosion ou d'une collision. Pour cela, nous partons du modèle de fragmentation de la NASA, Evolve ainsi que d'autres fonctions de distribution issus de diverses expériences de fragmentation. Grâce à ce modèle, nous obtenons des paramètres géométriques et également en termes de vitesse dont nous chercherons à déterminer leur influence sur le mouvement du nuage. / In 1957, the space conquest by man began with the successful launch into orbit of the first artificial satellite; Sputnik 1. This was the beginning of the exploitation of the earth's orbit characterized by a hundred of rocket launches starting from several launchpad such as Kourou or Baikonur. Today, the Earth's orbit has a population composed mostly of space debris. These include upper rocket stages, satellites which have ended their mission and other small artificial objects whose origin is not necessarily recognizable. Their number has become so important that it question the sustainability of space activities. In this thesis we figure out the difficulties to handle the issue posed by the space debris. In the first part of the thesis, we develop a fragmentation model to generate clouds of space debris as a result of an explosion or collision in space. For this, we mainly used the fragmentation model of NASA, Evolve, and other distribution functions from diverse experiences of fragmentation. Thanks to this model, we know the geometric parameters and also in terms of speed which we will seek to determine their influence on the movement of the cloud. Thus, in the second part of the thesis, we study the motion of space debris evolving initially in low Earth orbit.