Cette thèse consacrée à l'étude de collisions réactives dans les gaz d'intérêt énergétique a porté sur deux aspects. D'une part, la théorie du défaut quantique multi-voies (Multichannel Quantum Defect Theory : MQDT) [Giusti 1980, Nakashima 1987]a été utilisée pour étudier la recombinaison dissociative (RD), l'excitation vibrationnelle (EV) et la désexcitation vibrationnelle (dEV) de l'ion BeH+ et ses isotopomères dans leurs quatre plus bas niveaux vibrationnels initiaux (X1Σ+,v i+ =0,1,2,3). Les données moléculaires récemment calculées par nos collaborateurs [Roos 2009] ont été utilisées pour calculer les sections efficaces et taux de RD, EV et dEV en considérant les états des trois symétries moléculaires de BeH (2Π, 2Σ+ et 2∆ ). La dépendance vibrationnelle et l'effet isotopique sur les taux de processus collisionnels compétitifs ont été mis en évidence (Fig. V. 7). Une comparaison avec les résultats théoriques de Roos et al. 2009 obtenus à l'aide de la méthode des paquets d'ondes (Wave packets : WP) est effectuée. De cette comparaison, il ressort qu'il y a un bon accord entre les deux méthodes aux énergies intermédiaires. Ainsi, ce travail de thèse est en partie une extension de travail précédent de [Ross 2009]. L'approcheMQDT, capable de traiter complètement les capture temporaires d'électrons dans les éttats de Rydberg liés, ainsi que le couplage vibronique entre les voies d'ionisation, permet d'obtenir les premiers résultats (fiables) à basses énergies [Niyonzima 2013]. Ces taux de processus collisionnels sont utiles dans la modélisation du plasma de bord des machines à fusion [Celiberto 2012]. D'autres parts, nous avons fourni une formulation analytique approximative des sections efficaces de RD, EV, et dEV, utile pour la prédiction et l'interprétation des résultats du calcul numérique. Elle nous permet de comprendre les différentes interactions intramoléculaires et la sensibilité des taux de réaction par rapport aux interactions dominantes. / This thesis devoted to the study of reactive collisions in gases of energetic interest concerns two aspects. Firstly, a Multichannel-Quantum-Defect-Theory-type approach [Giusti 1980, Nakashima 1987] is used in the treatment of the dissociative recombination (DR), vibrational excitation (VE), and vibrational de-excitation (VdE) of BeH+ in their four lowest vibrational states (X1Σ+,v i+ =0,1,2,3). The molecular structure data previously computed [Roos 2009] have been employed in the calculations of cross sections and rate coefficients of DR, VE and VdE including three electronic symmetries of BeH (2Π, 2Σ+ et 2∆ ). The vibrational dependence [Niyonzima 2013] and the isotopic effects in these collisional processes are highlighted – Figure (V.7) – in order to be used in the modeling of the edge fusion plasma [Celiberto 2012]. Satisfactory agreement with results computed with the wave packet method [Roos 2009] is reached at intermediate energies [Niyonzima 2013]. Thereby, this part of the thesis work extends the previous study of [Roos 2009]. The MQDT-based approach, able to fully account for the temporary captures of electrons in Rydberg bound states, as well as the vibronic coupling between ionization channels, provides the first results (reliable) at low energies [Niyonzima 2013]. Lastly, an approximate analytical formulation of DR, VE and VdE cross section for the prediction and interpretation of results of numerical calculations has been provided. This formulation is usefull in the understanding of different intramolecular interactions and explains the sensibility of rate coefficients with respect to dominant interactions.

A Identificação por radiofrequência (Radio Frequency Identification - RFID) tem revolucionado a forma de identificar objetos, sendo usada desde aplicações de controle de estoques até o processo automatizado de pagamentos. Sua ampla aceitação e aplicabilidade tem estimulado pesquisadores a criar cada vez mais aplicações. Um problema chave da RFID são as colisões que ocorrem na identificação por meio dos protocolos de acesso múltiplo. Como, na prática, um leitor precisa identificar várias etiquetas em sua área de cobertura, algumas etiquetas podem responder ao mesmo tempo o que gera colisões e desperdício de recursos. Por este motivo, torna-se de grande valor um estudo abrangente sobre como melhorar a identificação das etiquetas de modo a reduzir o número de colisões. Além disso, aspectos como consumo de energia e tempo necessário para identificação também devem ser levados em consideração, uma vez que a utilização cada vez maior de dispositivos alimentados à bateria tem sido observada na prática. Esta tese investiga a categoria de protocolos anticolisão denominada Frame Slotted Aloha - FSA, pois é a categoria que possui maior potencial de utilização prática em sistemas RFID. Além disso, as diferentes métricas de análise de desempenho são também analisadas e categorizadas, uma vez que identificou-se que um conjunto de métricas devem ser observadas com o intuito de realizarem-se comparações justas com as propostas da literatura. Descobriu-se que a maioria das propostas não levam em consideração os aspectos chave de tempo e energia, assim como a característica de ser fácil de implementar e baixa complexidade. Esta tese propõe quatro algoritmos que visam diminuir o consumo de energia e o tempo do processo de identificação das etiquetas mantendo-se as características de baixa complexidade e similaridade com o padrão atual EpcGlobal Classe 1 Geração 2 (C1G2). O primeiro mecanismo visa diminuir a quantidade de respostas desnecessárias em cenários de localização e rastreamento. Os demais consistem em três propostas de algoritmos anticolisão para sistemas RFID. Os dois primeiros diferem na forma como o tamanho inicial de quadro é definido e como as colisões são tratadas, representando evoluções progressivas em direção a um melhor desempenho. O terceiro considera a ocorrência do efeito captura, o que traz a necessidade de mudanças no funcionamento do algoritmo anterior. Resultados de simulação mostram que os quatro mecanismos podem melhorar propostas existentes sem aumento de complexidade, resultando consequentemente em diminuição de recursos desperdiçados. Além disso também foram desenvolvidos dois softwares de apoio aos mecanismos propostos: nsRFIDsim e jRFIDsim. O primeiro trata-se de um módulo para o simulador ns-2 que simula um sistema RFID passivo. O segundo implementa uma proposta de benchmark para avaliação de desempenho de algoritmos anticolisão para RFID, visando fornecer para a comunidade científica uma forma padronizada de avaliar este tipo de algoritmo. / The Radio Frequency Identification - RFID has revolutionized the way objects are identified, being used in several areas, from inventory control applications to automated payment process. Its wide acceptance and applicability has stimulated researchers to create more and more new applications. One RFID key problem is the collisions on identification by means of multiple access protocols. Since generally, a reader needs to identify multiple tags in its coverage area, some tags tend to reply at the same time which can cause collision and waste of resources. For this reason a comprehensive study on how to improve the identification of tags in order to reduce the number of collisions becomes important. Additionally, issues such as energy consumption and time required for identification must also be taken into consideration, since an increasing use of battery-powered devices has been observed in practice. This thesis investigates the category of anti-collision protocols called Frame Slotted Aloha - FSA, as it is the category that has the greatest potential for practical use in RFID systems. Further analysis of the different performance metrics are also analyzed and categorized, since it was identified that a set of metrics must be observed in order to carry out up fair comparisons with the proposals found on the literature. It was found that most of the proposals do not consider the key aspects of time and energy as well as the characteristic of being easy to implement and having low complexity. This thesis proposes four algorithms aimed at reducing the consumption of energy and the time to identify the tags while maintaining the characteristics of low complexity and similarity to the current standard EPCglobal Class 1 Generation 2 (C1G2). The first mechanism aims to decrease the unnecessary answers in locating and tracking scenarios. The other ones consist of three proposals for anti-collision algorithms for RFID systems. They differ in how the initial size is defined and how collisions are resolved, representing progressive evolutions toward a better performance. The third one considers the occurrence of the capture effect, which brings the need for changes in the previous algorithm operation. Simulation results show that the four mechanisms can improve existing proposals without increasing complexity, resulting in consequent energy savings. In addition we have also developed two softwares to evaluate the proposed mechanisms: nsRFIDsim and jRFIDsim. The former is a module for the ns-2 simulator that simulates a passive RFID system. The second one implements a proposal for benchmark performance evaluation of anti-collision algorithms for RFID in order to provide to the scientific community a standardized way to assess this type of algorithm.

Twenty five porcine knee collateral ligaments were tested to determine the dynamic failure properties of ligaments. A test fixture, to be placed in a drop tower, was designed to apply an axial impulsive impact load to a porcine bone-ligament-bone complex. The applied strain rates ranged from 0.005s-1 to 145s-1. The data from the impact tests was analyzed using the method of linear regression to construct predictive model equations capable of forecasting the failure load and failure stress of a ligament subjected to a specific strain rate. 73% of the ligaments tested failed via tibial avulsion while the remaining ligaments failed via mid-substance tearing. The failure: load, strain and stress all increased with the applied strain rate. Further an interesting correlation between geometric ratios, namely the initial length divided by the initial cross sectional area and vice versa, and the failure load and stress were identified. Using this information, model equations were developed that predict the failure stresses based on the load and strain rate. The motivation for this study was to develop failure properties that could be used in an LSDYNA finite element model of the human lower extremities based on the understanding that the properties of porcine knee collateral ligaments would be similar to human ligaments. The properties developed in this study can be used to estimate the human response in high speed frontal automotive collisions.

Avec la complexité croissante des systèmes sur puce, la conception de la nouvelle génération des systèmes embarqués dédiée aux applications multimédia doit intégrer des structures de communication efficaces telles que le réseau sur puce (Network-on-Chip : NoC). Vu la limitation du nombre de ressources d’un seul FPGA, les plateformes multi-FPGA sont considérées comme la solution la plus appropriée pour émuler et évaluer ces grands systèmes. Le déploiement passe souvent par le partitionnement du NoC sur plusieurs FPGAs et de remplacer les liens de communications internes par des liens de communications externes. Cette solution possède des limitations. En fait, l’évolution des FPGAs tend à rendre les IOs des ressources rares aggravant la bande passante intra-FPGA d’une génération à une autre. Actuellement, le nombre de signaux inter-FPGA est considéré comme un problème majeur pour déployer un NoC à grand échelle sur multi-FPGA. Comme il y a plus de signaux à connecter que les IOs disponibles sur FPGA, un goulot d’étranglement important a été crée laissant les concepteurs soufrera. Les contributions principales de cette thèse sont : (1). Nous avons développé deux architectures de gestions de collisions, une basée sur un accès aléatoire (Backoff) et l’autre basée sur un accès planifié (Round-Robin). Des comparaisons temporelles et des ressources ont été effectuées pour choisir la méthode d’accès la plus performante pour prototyper un NoC sur multi-FPGA. L’architecture basée sur le Backoff permet de partager efficacement le lien externe entre plusieurs routeurs avec un nombre minimum de collisions. Ainsi, cet algorithme permet de gérer le goulet d’étranglement et équilibre les accès des routeurs vers l’inter-FPGA. La nouvelle architecture inter-FPGA pour le Network-on-Chip basée sur l’algorithme BackOff fournit une latence plus faible avec moins de ressources par rapport à d’autres solutions comme le RR (Round-Robin) et le HRRA (Hierarchical Roun-Robin Arbiter). (2) Une méthodologie de modélisation a été émergée pour estimer le nombre de ressources utilisées par chaque architecture. Cette modélisation est basée sur la régression linéaire. Il y a des grandes surestimations avec le round-robin qu’avec le Backoff. (3) Finalement, une architecture de NoC dédiée aux applications multimédias a été proposée. L’objective de cette architecture est de transmettre des trafics avec des niveaux de priorités différentes dans des bonnes conditions. Dans cette architecture de NoC multimédia, nous avons doublé les liens physiques au lieu d’utiliser des canaux virtuels pour permettre aux trafics de haute priorité de récupérer le retard. De plus, nous avons intégré à l’intérieur des routeurs un simple arbitre pour traiter les niveaux de priorité pour chaque paquet. Cette nouvelle architecture a été comparée avec des architectures de NoC traditionnelles avec (basée sur des canaux virtuels) ou sans (NoC Handshake) qualité de service. Plusieurs testsont été effectués pour prouver l’efficacité de l’architecture du NoC multimédia. Finalement, une étude analytique a été proposée pour estimer le nombre d’AP nécessaires pour que cette architecture de NoC multimédia afin de répondre aux exigences d’utilisateurs dans le contexte de multi-FPGA / With the increasing complexity of System-on-Chip, the design of efficient embedded systems dedicated for multimedia applications must integrate effective communication interconnects such as Network-on-Chip. Given the limited number of resources of a single FPGA, multi-FPGA platforms are considered the most appropriate means for experimentation, emulation and evaluation for such large systems. Deployment often involves partitioning the Network-on-Chip on several FPGA and replacing internal communication links with external ones. The limitation of this solution stems from the fact that with ongoing evolution of FPGAs, their I/O resources become scarcer in time. This, consequently, decreases intra-FPGA bandwidth. Currently, the number of inter-FPGA signals is considered a major problem to prototype a Network-on-Chip on multi-FPGA. Since there are more signals needed for routers than the number of available FPGA I/Os. Therefore, inter-FPGA links must be shared between routers, resulting in significant bottlenecks. Since the ratio of logical capacity to the number of IOs increases slowly for each FPGA generation, this technological bottleneck will be remaining for future system designs.The main contributions of this thesis are : (1). We have developed two collision management architectures, one is based on a random access (Backoff) and the other is based on a round-robin algorithm. Timing and resources comparisons are made to evaluate the two inter-FPGA traffic management architectures. The Backoff-based sub-NoC architecture effectively shares external links between multiple routers with a minimum number of collision and balances access between all routers. The new inter-FPGA architecture for the Network-on-Chip based on the BackOff algorithm achieves lower latency with fewer resources compared to other solutions such as Round-Robin and Hierarchical Round-Robin Arbiter. (2) A modeling methodology has emerged to estimate the number of resources used by each architecture. This modeling is based on linear regression. There are considerable over-estimations in the round-robin compared to the Backoff. (3) A NoC architecture dedicated for multimedia applications has been proposed. The objective of such architecture is to transmit traffic with different priority levels under right conditions. In this architecture of NoC multimedia, we have doubled the physical links instead of using virtual channels to allow high priority traffic to recover the delay and to ensure quality of service. In Additionally we have integrated within the routers a simple arbiter to deal with the priority levels for each packet. This new architecture has been compared with traditional architecture based on virtual channels using several test partitioning. Finally, an analytical study was proposed to estimate the number of APs needed for the NoC Multimedia deployed in multi-FPGA systemse to meet the user’s requirements

Ion mobility spectrometry is a powerful technique for the study related to molecule. The work of tow major applications are introduced in this paper. The first application is the optimization of parameters in CCS. The accurate calculation of the collision cross section for multiple molecules is a long-time interested topic in the research for substances detection in micro scale. No reliable analytical approach to calculate the collision cross section has been established to date. Different approaches rely on different mechanism will provide different results in significant extent. This work introduce a method for the determination of parameters in the Lennard Jones potential. Experimental data combined with numerical computation was the fundamental strategy during the optimization of the parameters. In the experiment, electrospray is used as the ion source of IMS while a nebulizer was utilized to electrify the aromatic compounds. New parameters show no less accuracy and equal efficiency while can explain the physical meaning of the collision more clearly. The second application is the trace detection of explosives with very low concentration. The detection of explosives is an important topic in security, while the detection will be difficult due to the low vapor pressure of explosives. In this work, two types of devices are designed for the trace detection of explosives at an extremely low concentration. TNT is selected as the explosives in the experiment. The experiment succeed to reach a sensitivity of 1 part per quintillion, and even find out a linear relationship between the logarithm of TNT concentration and TNT vapor pressure.

A proposta deste trabalho é demonstrar a viabilidade de um sistema para inserção de um vídeo-avatar interativo em um ambiente virtual 3D, utilizando-se somente um computador pessoal e câmeras domésticas. Sua contribuição, em relação a trabalhos similares, consiste em integrar técnicas e algoritmos em uma solução inovadora de baixo custo computacional, voltada principalmente para aplicações de educação e entretenimento. Este trabalho expande as pesquisas realizadas anteriormente no Laboratório de Tecnologias Interativas sobre vídeo-avatares para teleconferência. O vídeo-avatar proposto é posicionado corretamente em relação a outros objetos do ambiente virtual e pode interagir com eles, sem a utilização de técnicas de reconstrução geométrica que apresentam altos custos de processamento. A demonstração da viabilidade da proposta é feita através da implementação de protótipos. / The proposal of this work is to demonstrate the feasibility of a system for the insertion of an interactive video avatar in a 3D virtual environment, using a single personal computer and home-use cameras. Its contribution, relative to similar works, consists in integrating techniques and algorithms in an innovative solution with low computational cost, aimed mainly at educational and entertainment applications. This work extends research previously performed at the Laboratório de Tecnologias Interativas about video avatars for teleconferencing. The proposed video avatar is correctly positioned in relation to other objects in the virtual environment and is capable of interacting with them, without resorting to geometric reconstruction techniques that present high processing costs. The demonstration of the feasibility of the proposal is performed through the implementation of prototypes.

A física de altas energias, mais especificamente o estudo de colisões entre de íons pesados relativísticos tem como objetivo o estudo do comportamento de quarks e glúons em condições extremas de temperatura, pressão e densidade. Tais condições levam à formação de um novo estado da matéria chamado Plasma de Quarks e Glúons (QGP, do inglês Quark-Gluon Plasma). Medidas de observáveis globais tem sido usadas como uma importante ferramenta para a caracterização desse novo estado. Entre esses observáveis, a energia transversal por unidade de rapidez (dET/dy) das partículas emitidas em uma colisão entre íons pesados pode ser usada como evidência da formação do QGP. Este trabalho propõe um procedimento para obtenção da energia transversal eletromagnética, que é um importante componente da energia transversal total, em colisões Pb-Pb no experimento ALICE no LHC. O estudo foi feito através de simulações de Monte Carlo e validou o procedimento proposto com uma diferença sistemática em função da centralidade em torno de 2%. / High energy physics with heavy ion collisions studies quarks and gluons under extreme conditions of temperature, pressure and density. Such conditions lead to the formation of a new state of matter called the Quark-Gluon Plasma (QGP). The measurement of global observables have been used as an important tool for the characterization of this new state. Among these observables, the transverse energy per unit of rapidity (dET/dy) from particles emitted in a heavy ion collision can be used as evidence of QGP formation. The work proposes a procedure to obtain the transverse electromagnetic energy, an important component of total transverse energy, in Pb-Pb collisions measured by the LHC-ALICE experiment. The study was done using Monte Carlo simulations, and validated the proposed procedure with a systematic difference as function of the centrality around 2%.

No description available.

The amino acid sequence of a protein determines its 3D fold, the ease with which its native structure is formed, its function, the conformational preferences sampled and the tendency to interact with itself (aggregation) and binding partners. In addition, certain conformational preferences can lead to dysfunction resulting in different diseased states in organisms. All of these conformations can be described by a protein's energy landscape; a native (functional) state being localised at the energy minimum. As protein dynamics is crucial to function it is important to monitor the sampling of different conformations. Thus the work in this thesis reports on two methods for monitoring protein conformation and conformational change in the gas phase using ion mobility mass spectrometry (IM-MS). The measurement from IM-MS methods allow the determination of a collision cross section (CCS) which is an indicator of a molecule's 3D shape. First, the effect of charge on protein structure is investigated by manipulation of protein charge, post electrospray ionisation (ESI), by exposure to radical anions of the electron transfer reagent, 1,3-dicyanaobenzene; the charge reduced products formed are the result of electron transfer to the charged protein without any dissociation (ETnoD). IM-MS is used to monitor the conformational preferences of the altered and unaltered precursor and its products. Secondly, intermediate (transient) conformers are formed by activating the charged protein in the source region of an instrument post ESI. Activation of the protein precursor allows the sampling of different conformational preferences after energetic barriers have been overcome; IM-MS following activation allows for the monitoring of protein conformational change before and after. Further, variable temperature (VT) IM-MS allows for the deduction of intermediate structures with a focus on measurements at cryogenic temperatures whereby intermediate structures can be 'frozen out' post activation; intermediate structures which would otherwise anneal out at room temperature. With both methods a range of conformer populations are mapped for different protein molecules sampled upon different energetic inputs (via activation) and the disruption of intramolecular neutralising contacts/salt bridges (via charge reduction) one of the main interactions responsible for maintaining the structural integrity (3D fold) of proteins.

Muslim groups in Karlstad are rarely visible online. There is also no previous research about them. Through an interview-based mapping study, I want to research what activities take place in Muslim mosques in Karlstad. The aim of the study is to document and analyze Muslim activities. This study is included in a research project at Karlstad University: Karlstad’s mosque - negotiations on Islam in Värmland. It aims to illuminate Islam’s development in Värmland from various aspects. Religious change and religion collision are theoretical starting points for the study. The results of this study show that three congregations are active in Karlstad: Islamiska Kulturföreningen [sunni], Bosniska Islamiska Kulturföreningen [sunni] and Mahdi Al Montazar [shia]. They established their congregations since 1990s. They are dependent on their main organizations and do not cooperate with other Muslim associations. Members of the congregation are very important for the organization’s existence. The result indicates that the religious activities of groups are not affected by data-based communication. Different branches work for their own community and have different views about Islam. In a Christian society, these Muslim congregations try to adapt to the rules of majority society in different ways. They find new ways to practise their religion. Minority groups want to preserve their own cultural and religious traditions through the mosque building or association board. It will be a way to be included and recognized by the majority.