This research concerns exploiting knowledge of the user's environment (i.e., context information) to enrich a user's communication making it more personal, by ensuring that the user receives only relevant messages and calls in his/her current context, and to facilitate more opportunities for communication interactions with people that are in the same context and that share the same interests as this user. We describe in this licentiate thesis the concepts of context-addressed messaging and context-aware session control that enable users to: (1) send messages to others based on their context, rather than their network address and (2) to initiate, adapt, and terminate user's communication sessions based on this user's current context, respectively. These concepts address questions such as: how to discover, select, and switch to an optimal communication means to meet varying user, contextual, communication, and device resource requirements and preferences. A key to solving these problems is to create a representation of the user's context-dependent preferences and to process the user's context-dependent preferences which are part of context triggers. These context triggers can initiate a communication event upon a particular context update. Additionally, in order to provide the described context-aware communication functions, these mechanisms need timely access to the acquired (desired) context information. This in turn raises a plethora of other questions, such as how to discover sensors that provide the desired context information; how to acquire raw context data from these sensors; how to abstract, process, and model this data to become "understandable" to applications and system components; and how to distribute this context to applications that are running on different nodes.   This research is split into three different parts. The first part concerns investigating and implementing context management functions. As part of this research we propose a novel approach for context synthesis using context operators. We also propose a design architecture for context-aware middleware that mediates between the sensors and applications, and that is able to share and retrieve context from other nodes in the network. The second part of our research concerns our proposed mechanism for context-addressed messaging. To implement this mechanism we designed our own message format, called the Common Profile for Context-Addressed Messaging (CPCAM) that is able to use any high level context to compose a context-based address. Additionally, we proposed to use context-based filtering to find the correct message recipients and determine if this message is relevant to these potential message recipients in their current context, as well as to deliver this message to the recipients' preferred device that is adapted using their preferred communication means. At the end of this second part we design context-addressed messaging system operations on top of a SIP and SIMPLE-based network infrastructure. The third part of our research describes context-aware session control mechanisms using context switch and context trigger constructs. A context-switch selects an action from a set of context-dependent actions upon an incoming communication event based on the receiver's current context. In contrast, a context trigger initiates an action based on a context update and the user's preferences that are specified in this updated context. This part illustrates in several examples the context-aware session control mechanisms, i.e. the initiation of a communication session based on the match of a user's preferences and current context, as well as adaptation and (if necessary) termination of an ongoing communication session based upon the user's context-dependent preferences.   The research leading to this licentiate has created network and system level models necessary for implementation of a context-addressed communication system that would enable users to easily design their own personalized, context-aware communication services. The necessary constructs and properties of these models are designed and analyzed in the thesis, as well as in conference papers and other documents published in the process of doing the research for this thesis. A number of remaining open issues and challenges have been outlined as part of the future work. / EU FP6 MIDAS (Middleware Platform for Developing and Deploying Advanced Mobile Services) / EU FP6 MUSIC (Self-adapting Applications for Mobile Users In Ubiquitous Computing Environments)

Dans le domaine des réseaux, deux précieux objectifs doivent être atteints, à savoir la QoS et la sécurité, plus particulièrement lorsqu’il s’agit des réseaux à caractère critique et à fortes contraintes temporelles. Malheureusement, un conflit existe : tandis que la QoS œuvre à réduire les temps de traitement, les mécanismes de sécurité quant à eux requièrent d’importants temps de traitement et causent, par conséquent, des délais et dégradent la QoS. Par ailleurs, les systèmes temps réel, la QoS et la sécurité ont très souvent été étudiés séparément, par des communautés différentes. Dans le contexte des réseaux avioniques de données, de nombreux domaines et applications, de criticités différentes, échangent mutuellement des informations, souvent à travers des passerelles. Il apparaît clairement que ces informations présentent différents niveaux de sensibilité en termes de sécurité et de QoS. Tenant compte de cela, le but de cette thèse est d’accroître la robustesse des futures générations de réseaux avioniques de données en contrant les menaces de sécurité et évitant les ruptures de trafic de données. A cet effet, nous avons réalisé un état de l’art des mécanismes de sécurité, de la QoS et des applications à contraintes temporelles. Nous avons, ensuite étudié la nouvelle génération des réseaux avioniques de données. Chose qui nous a permis de déterminer correctement les différentes menaces de sécurité. Sur la base de cette étude, nous avons identifié à la fois les exigences de sécurité et de QoS de cette nouvelle génération de réseaux avioniques. Afin de les satisfaire, nous avons proposé une architecture de passerelle de sécurité tenant compte de la QoS pour protéger ces réseaux avioniques et assurer une haute disponibilité en faveur des données critiques. Pour assurer l’intégration des différentes composantes de la passerelle, nous avons développé une table de session intégrée permettant de stocker toutes les informations nécessaires relatives aux sessions et d’accélérer les traitements appliqués aux paquets (filtrage à états, les traductions d’adresses NAT, la classification QoS et le routage). Cela a donc nécessité, en premier lieu, l'étude de la structure existante de la table de session puis, en second lieu, la proposition d'une toute nouvelle structure répondant à nos objectifs. Aussi, avons-nous présenté un algorithme permettant l’accès et l’exploitation de la nouvelle table de session intégrée. En ce qui concerne le composant VPN IPSec, nous avons détecté que le trafic chiffré par le protocole ESP d’IPSec ne peut pas être classé correctement par les routeurs de bordure. Afin de surmonter ce problème, nous avons développé un protocole, Q-ESP, permettant la classification des trafics chiffrés et offrant les services de sécurité fournis par les protocoles AH et ESP combinés. Plusieurs techniques de gestion de bande passante ont été développées en vue d’optimiser la gestion du trafic réseau. Pour évaluer les performances offertes par ces techniques et identifier laquelle serait la plus appropriée dans notre cas, nous avons effectué une comparaison basée sur le critère du délai, par le biais de tests expérimentaux. En dernière étape, nous avons évalué et comparé les performances de la passerelle de sécurité que nous proposons par rapport à trois produits commerciaux offrant les fonctions de passerelle de sécurité logicielle en vue de déterminer les points forts et faibles de notre implémentation pour la développer ultérieurement. Le manuscrit s’organise en deux parties : la première est rédigée en français et représente un résumé détaillé de la deuxième partie qui est, quant à elle, rédigée en anglais. / QoS and security are two precious objectives for network systems to attain, especially for critical networks with temporal constraints. Unfortunately, they often conflict; while QoS tries to minimize the processing delay, strong security protection requires more processing time and causes traffic delay and QoS degradation. Moreover, real-time systems, QoS and security have often been studied separately and by different communities. In the context of the avionic data network various domains and heterogeneous applications with different levels of criticality cooperate for the mutual exchange of information, often through gateways. It is clear that this information has different levels of sensitivity in terms of security and QoS constraints. Given this context, the major goal of this thesis is then to increase the robustness of the next generation e-enabled avionic data network with respect to security threats and ruptures in traffic characteristics. From this perspective, we surveyed the literature to establish state of the art network security, QoS and applications with time constraints. Then, we studied the next generation e-enabled avionic data network. This allowed us to draw a map of the field, and to understand security threats. Based on this study we identified both security and QoS requirements of the next generation e-enabled avionic data network. In order to satisfy these requirements we proposed the architecture of QoS capable integrated security gateway to protect the next generation e-enabled avionic data network and ensure the availability of critical traffic. To provide for a true integration between the different gateway components we built an integrated session table to store all the needed session information and to speed up the packet processing (firewall stateful inspection, NAT mapping, QoS classification and routing). This necessitates the study of the existing session table structure and the proposition of a new structure to fulfill our objective. Also, we present the necessary processing algorithms to access the new integrated session table. In IPSec VPN component we identified the problem that IPSec ESP encrypted traffic cannot be classified appropriately by QoS edge routers. To overcome this problem, we developed a Q-ESP protocol which allows the classifications of encrypted traffic and combines the security services provided by IPSec ESP and AH. To manage the network traffic wisely, a variety of bandwidth management techniques have been developed. To assess their performance and identify which bandwidth management technique is the most suitable given our context we performed a delay-based comparison using experimental tests. In the final stage, we benchmarked our implemented security gateway against three commercially available software gateways. The goal of this benchmark test is to evaluate performance and identify problems for future research work. This dissertation is divided into two parts: in French and in English respectively. Both parts follow the same structure where the first is an extended summary of the second.

A pesquisa aborda teórica e clinicamente a cadeia associativa grupal e sua especificidade, quando se utiliza como mediador terapêutico o pictograma grupal. Ela tem como objetivo acrescentar e aprofundar o estudo já realizado, no qual o desenhar conjunto pode introduzir modalidades associativas específicas que articulam o discurso do sujeito e do grupo (Pezo, 2009). O trabalho com grupos instaura processos associativos distintos dos descritos pela psicanálise, no enquadre clássico, segundo Kaës (1994, 2005, 2008, 2010) devido à presença de vários sujeitos simultaneamente e aos efeitos da interdiscursividade. Com o conceito de cadeia associativa grupal, Kaës (1985) define a especificidade da associação livre, que junto com a transferência e a interpretação, permitem o conhecimento dos efeitos do inconsciente no grupo. As cadeias articulam processos inter-relacionados entre si, as associações do sujeito singular e as produzidas intersubjetivamente no grupo. Quando, para além da palavra, se inclui no grupo um mediador terapêutico, como o pictograma grupal, o processo associativo apresenta marcas específicas. Entre elas, uma cadeia associativa de: traço para desenho; de desenho para desenho; de desenho para palavra; de palavra para narrativa. No pictograma grupal, aspectos inusitados, impensados se incluem de maneira semelhante ao lapso de linguagem graças ao trabalho do pré-consciente, do desenhar conjunto e, fundamentalmente, aos efeitos da presença múltipla de sujeitos. A consulta terapêutica proposta por Winnicott para atender crianças reconhece o valor da utilização do método psicanalítico em um atendimento, sem por isso estar realizando uma psicanálise padrão. Esse modelo de consulta é estendido para o atendimento de grupo e família, com o uso do pictograma grupal, em situações pontuais. Propõe-se a utilidade do mediador no trabalho institucional com pacientes psicóticos, psicossomáticos, com tendência de passagem ao ato. Considera-se que o recurso do pictograma grupal, ainda pouco explorado no campo das práticas institucionais, pode ser um facilitador para enunciar aquilo que não pode ser nomeado ou representado simbolicamente devido ao medo, ou a mecanismos como a repressão, o recalque, a denegação, entre outros. As cadeias associativas grupais propiciadas pelo uso do pictograma grupal evidenciam que simultaneamente é possível elaborar e transformar o sujeito apropriando-se subjetivamente da experiência, as relações intersubjetivas e o grupo, graças ao trabalho associativo grupal. Utilizamos o pictograma, em consultas terapêuticas com grupos e com famílias, em um enquadre de dois a três encontros. Destacamos a relevância do pictograma grupal, em outros contextos como situações traumáticas individuais ou sociais / This research discusses, from a theoretical and clinical point of view, the group association chain and its specificity when one uses the group pictogram as therapeutic mediator. Its goal is to add to and deepen the study previously made, in which the collective drawing may introduce specific kinds of association that articulate the subjects and the groups speech (Pezo, 2009). Working with groups creates association processes different from the ones described by psychoanalysis in the classical model, according to Kaës (1994, 2005, 2008, 2010) due to the presence of various subjects simultaneously and to the effects of interdiscursivity. This concept developed by Kaës (1985) defines the specificity of free association which, together with transfer and interpretation, allows one to know the unconscious impact on a group. The chains articulate interrelated processes, the single subject associations and the ones inter-subjectively created by the group. When one includes a therapeutic mediator beyond the word, such as the group pictogram, the association process presents unique characteristics, among them an association chain from: trait to drawing; from drawing to drawing, from drawing to word and from word to narration. In the group pictogram unprecedented and unthought aspects are similarly included in the language slip thanks to the work of the preconscious, the drawing together and, basically, to the effects of the presence of multiple subjects. The therapeutic session proposed by Winnicott acknowledges the value of using the psychoanalytic method in a process, which does not mean that one is performing a standard psychoanalytic treatment. This session method is extended to the group and family treatment, using the group pictogram in punctual situations. Our proposal is to use a mediator for the institutional work with psychotic patients, tending to proceed to the act with psychosomatic traumas due to difficulty to communicate only orally. It is believed that the group pictogram resource, which is still little exploited in the institutional practices area, may facilitate the enunciation of something that cannot be named or symbolically represented due to fear or mechanisms such as suppression, repression and denegation, among others. The group association chains provided by the use of the group pictogram show that it is possible to develop and transform at the same time: the individual subjectively acquiring the experience, the intersubjective relationships and the group, thanks to the group association work and the effects of intersubjectivity and interdiscursivity. We have used the pictogram in therapeutic sessions with groups and families in a model of two or three sessions. We would like to point out the relevance of the group pictogram in other contexts such as individual or social traumatic situations

La sécurité est un enjeu majeur de notre société numérique. En règle générale, les techniques cryptographiques sont utilisées pour sécuriser l'information avec des clés cryptographiques. Un inconvénient majeur de ces systèmes est le faible lien entre les clés et l’utilisateur. Avec la biométrie on a une preuve plus forte de la présence physique d’un individu, mais ces systèmes possèdent aussi leurs inconvénients, tels que la non-révocabilité ainsi que le potentiel de compromettre notre vie privée. Un axe de recherche multidisciplinaire se profile depuis 1998, la crypto-biométrie. Dans cette thèse des solutions innovantes sont proposées pour améliorer la sécurité tout en protégeant notre vie privée. Plusieurs systèmes crypto-biométriques sont proposés, tels que la biométrie révocable, des systèmes de régénérations de clés crypto-biométriques, ainsi qu’une proposition pratique d’un protocole d'authentification. Ces systèmes sont évaluées sur des bases de données publiques d'images de visage et d'iris / Securing information during its storage and transmission is an important and widely addressed issue. Generally, cryptographic techniques are used for information security. Cryptography requires long keys which need to be kept secret in order to protect the information. The drawback of cryptography is that these keys are not strongly linked to the user identity. In order to strengthen the link between the user's identity and his cryptographic keys, biometrics is combined with cryptography. In this thesis, we present various methods to combine biometrics with cryptography. With this combination, we also address the privacy issue of biometric systems: revocability, template diversity, and privacy protection are added to the biometric verification systems. Finally, we also present a protocol for generating and sharing biometrics based crypto-biometric session keys. These systems are evaluated on publicly available iris and face databases

Les moteurs de recherche, largement utilisés dans différents domaines, sont devenus la principale source d'information pour de nombreux utilisateurs. Cependant, les Systèmes de Recherche d'Information (SRI) font face à de nouveaux défis liés à la croissance et à la diversité des données disponibles. Un SRI analyse la requête soumise par l'utilisateur et explore des collections de données de nature non structurée ou semi-structurée (par exemple : texte, image, vidéo, page Web, etc.) afin de fournir des résultats qui correspondent le mieux à son intention et ses intérêts. Afin d'atteindre cet objectif, au lieu de prendre en considération l'appariement requête-document uniquement, les SRI s'intéressent aussi au contexte de l'utilisateur. En effet, le profil utilisateur a été considéré dans la littérature comme l'élément contextuel le plus important permettant d'améliorer la pertinence de la recherche. Il est intégré dans le processus de recherche d'information afin d'améliorer l'expérience utilisateur en recherchant des informations spécifiques. Comme le facteur temps a gagné beaucoup d'importance ces dernières années, la dynamique temporelle est introduite pour étudier l'évolution du profil utilisateur qui consiste principalement à saisir les changements du comportement, des intérêts et des préférences de l'utilisateur en fonction du temps et à actualiser le profil en conséquence. Les travaux antérieurs ont distingué deux types de profils utilisateurs : les profils à court-terme et ceux à long-terme. Le premier type de profil est limité aux intérêts liés aux activités actuelles de l'utilisateur tandis que le second représente les intérêts persistants de l'utilisateur extraits de ses activités antérieures tout en excluant les intérêts récents. Toutefois, pour les utilisateurs qui ne sont pas très actifs dont les activités sont peu nombreuses et séparées dans le temps, le profil à court-terme peut éliminer des résultats pertinents qui sont davantage liés à leurs intérêts personnels. Pour les utilisateurs qui sont très actifs, l'agrégation des activités récentes sans ignorer les intérêts anciens serait très intéressante parce que ce type de profil est généralement en évolution au fil du temps. Contrairement à ces approches, nous proposons, dans cette thèse, un profil utilisateur générique et sensible au temps qui est implicitement construit comme un vecteur de termes pondérés afin de trouver un compromis en unifiant les intérêts récents et anciens. Les informations du profil utilisateur peuvent être extraites à partir de sources multiples. Parmi les méthodes les plus prometteuses, nous proposons d'utiliser, d'une part, l'historique de recherche, et d'autre part les médias sociaux. / Recently, search engines have become the main source of information for many users and have been widely used in different fields. However, Information Retrieval Systems (IRS) face new challenges due to the growth and diversity of available data. An IRS analyses the query submitted by the user and explores collections of data with unstructured or semi-structured nature (e.g. text, image, video, Web page etc.) in order to deliver items that best match his/her intent and interests. In order to achieve this goal, we have moved from considering the query-document matching to consider the user context. In fact, the user profile has been considered, in the literature, as the most important contextual element which can improve the accuracy of the search. It is integrated in the process of information retrieval in order to improve the user experience while searching for specific information. As time factor has gained increasing importance in recent years, the temporal dynamics are introduced to study the user profile evolution that consists mainly in capturing the changes of the user behavior, interests and preferences, and updating the profile accordingly. Prior work used to discern short-term and long-term profiles. The first profile type is limited to interests related to the user's current activities while the second one represents user's persisting interests extracted from his prior activities excluding the current ones. However, for users who are not very active, the short-term profile can eliminate relevant results which are more related to their personal interests. This is because their activities are few and separated over time. For users who are very active, the aggregation of recent activities without ignoring the old interests would be very interesting because this kind of profile is usually changing over time. Unlike those approaches, we propose, in this thesis, a generic time-sensitive user profile that is implicitly constructed as a vector of weighted terms in order to find a trade-off by unifying both current and recurrent interests. User profile information can be extracted from multiple sources. Among the most promising ones, we propose to use, on the one hand, searching history. Data from searching history can be extracted implicitly without any effort from the user and includes issued queries, their corresponding results, reformulated queries and click-through data that has relevance feedback potential. On the other hand, the popularity of Social Media makes it as an invaluable source of data used by users to express, share and mark as favorite the content that interests them.

A pesquisa aborda teórica e clinicamente a cadeia associativa grupal e sua especificidade, quando se utiliza como mediador terapêutico o pictograma grupal. Ela tem como objetivo acrescentar e aprofundar o estudo já realizado, no qual o desenhar conjunto pode introduzir modalidades associativas específicas que articulam o discurso do sujeito e do grupo (Pezo, 2009). O trabalho com grupos instaura processos associativos distintos dos descritos pela psicanálise, no enquadre clássico, segundo Kaës (1994, 2005, 2008, 2010) devido à presença de vários sujeitos simultaneamente e aos efeitos da interdiscursividade. Com o conceito de cadeia associativa grupal, Kaës (1985) define a especificidade da associação livre, que junto com a transferência e a interpretação, permitem o conhecimento dos efeitos do inconsciente no grupo. As cadeias articulam processos inter-relacionados entre si, as associações do sujeito singular e as produzidas intersubjetivamente no grupo. Quando, para além da palavra, se inclui no grupo um mediador terapêutico, como o pictograma grupal, o processo associativo apresenta marcas específicas. Entre elas, uma cadeia associativa de: traço para desenho; de desenho para desenho; de desenho para palavra; de palavra para narrativa. No pictograma grupal, aspectos inusitados, impensados se incluem de maneira semelhante ao lapso de linguagem graças ao trabalho do pré-consciente, do desenhar conjunto e, fundamentalmente, aos efeitos da presença múltipla de sujeitos. A consulta terapêutica proposta por Winnicott para atender crianças reconhece o valor da utilização do método psicanalítico em um atendimento, sem por isso estar realizando uma psicanálise padrão. Esse modelo de consulta é estendido para o atendimento de grupo e família, com o uso do pictograma grupal, em situações pontuais. Propõe-se a utilidade do mediador no trabalho institucional com pacientes psicóticos, psicossomáticos, com tendência de passagem ao ato. Considera-se que o recurso do pictograma grupal, ainda pouco explorado no campo das práticas institucionais, pode ser um facilitador para enunciar aquilo que não pode ser nomeado ou representado simbolicamente devido ao medo, ou a mecanismos como a repressão, o recalque, a denegação, entre outros. As cadeias associativas grupais propiciadas pelo uso do pictograma grupal evidenciam que simultaneamente é possível elaborar e transformar o sujeito apropriando-se subjetivamente da experiência, as relações intersubjetivas e o grupo, graças ao trabalho associativo grupal. Utilizamos o pictograma, em consultas terapêuticas com grupos e com famílias, em um enquadre de dois a três encontros. Destacamos a relevância do pictograma grupal, em outros contextos como situações traumáticas individuais ou sociais / This research discusses, from a theoretical and clinical point of view, the group association chain and its specificity when one uses the group pictogram as therapeutic mediator. Its goal is to add to and deepen the study previously made, in which the collective drawing may introduce specific kinds of association that articulate the subjects and the groups speech (Pezo, 2009). Working with groups creates association processes different from the ones described by psychoanalysis in the classical model, according to Kaës (1994, 2005, 2008, 2010) due to the presence of various subjects simultaneously and to the effects of interdiscursivity. This concept developed by Kaës (1985) defines the specificity of free association which, together with transfer and interpretation, allows one to know the unconscious impact on a group. The chains articulate interrelated processes, the single subject associations and the ones inter-subjectively created by the group. When one includes a therapeutic mediator beyond the word, such as the group pictogram, the association process presents unique characteristics, among them an association chain from: trait to drawing; from drawing to drawing, from drawing to word and from word to narration. In the group pictogram unprecedented and unthought aspects are similarly included in the language slip thanks to the work of the preconscious, the drawing together and, basically, to the effects of the presence of multiple subjects. The therapeutic session proposed by Winnicott acknowledges the value of using the psychoanalytic method in a process, which does not mean that one is performing a standard psychoanalytic treatment. This session method is extended to the group and family treatment, using the group pictogram in punctual situations. Our proposal is to use a mediator for the institutional work with psychotic patients, tending to proceed to the act with psychosomatic traumas due to difficulty to communicate only orally. It is believed that the group pictogram resource, which is still little exploited in the institutional practices area, may facilitate the enunciation of something that cannot be named or symbolically represented due to fear or mechanisms such as suppression, repression and denegation, among others. The group association chains provided by the use of the group pictogram show that it is possible to develop and transform at the same time: the individual subjectively acquiring the experience, the intersubjective relationships and the group, thanks to the group association work and the effects of intersubjectivity and interdiscursivity. We have used the pictogram in therapeutic sessions with groups and families in a model of two or three sessions. We would like to point out the relevance of the group pictogram in other contexts such as individual or social traumatic situations

Cette thèse présente une solution pour améliorer la mobilité des réseaux, dans le cadre de communications véhiculaires ainsi que pour la distribution de contenu. Les solutions actuelles pour les communications véhiculaires (c'est-à-dire lorsqu'un réseau est mobile) reposent sur la mise en place de tunnels, permettant également d'utiliser simultanément les différentes interfaces disponibles sur le véhicule (multi-homing). Même avec des tunnels, ces solutions ne sont pas en mesure d'équilibrer le trafic sur les interfaces réseau disponibles, elles ne parviennent pas à tirer partie du multi-homing. De plus, certaines des solutions existantes pour la mobilité de réseau cachent la mobilité aux hôtes connectés au routeur mobile. De fait, cela empêche les hôtes de participer aux décisions relatives au multi-homing, telles que le choix de l'interface réseau à utiliser, ce qui est pourtant utile pour réaliser du routage à moindre coût. Dans cette thèse, nous proposons de combiner un protocole de mobilité réseau (tel que NEMO) avec le protocole de TCP-multivoies (MPTCP), ce qui permet aux nœuds hôtes de participer à la mobilité et au multi-homing. Cette nouvelle combinaison améliore significativement le routage et l'encapsulation de paquets causée par les tunnels. En outre, cela augmente le débit, la tolérance de panne, le temps d'aller-retour et réduit le délai de transmission. La deuxième contribution de ce travail propose une solution de continuité de session pour la distribution de contenu dans les réseaux 5G. Dans le réseau 5G, les équipements d'accès IP seront au plus proche des nœuds terminaux afin d'améliorer l'expérience utilisateur et de réduire la charge de trafic dans le réseau central. Le fait est qu'à un instant donné un terminal ne peut être raccordé qu'à une seule passerelle (SGW/PGW) à la fois. Et comme la passerelle change lors de la mobilité, les sessions en cours seront rompues, impactant les applications temps réelle, le streaming vidéo, les jeux, etc. Pour cela, la thèse présente une solution de continuité de session avec l'aide de TCP-multivoie en bénéficiant du fait que les serveurs de contenu sont stationnaires. / This thesis presents a solution for boosting network mobility in the context of vehicular communications and content distribution in fixed network. Existing solutions for vehicular communications (i.e., network mobility), relies on tunneling in order to use multiple available interfaces on a vehicle. Even with tunnels, these solutions are unable to balance the traffic over available network interfaces thus do not reach the goal to provide optimum multi-homing benefits. Moreover, some of the existing solutions for network mobility, hide the mobility from the hosts connected to the mobile router. This in result inhibits the host nodes from participating in multi-homing related decisions such as interface selection which can be helpful in performing least cost routing. In this thesis, we propose to combine network mobility protocol with MPTCP which enables the host nodes to participate in mobility and multi-homing. This novel combination significantly improves routing and tunneling packet overhead. Moreover it increases throughput, fault tolerance, round-trip time and reduces transmission delay. The second contribution of this work is providing a solution for session continuity in context of content distribution in 5G networks. In 5G network, the IP edges will be closer to the host nodes in order to improve the user experience and reduce traffic load in the core network. The fact that a host can only be connected to a single gateway (SGW/PGW) at a time, would break the ongoing sessions for real time applications like video streaming or gaming during an occurrence of mobility event requiring gateway relocation. The thesis presents the solution for session continuity with the help of multipath TCP by benefiting from the fact that the content servers are stationary.

Radioactive decay of nuclei via emission of ??-particles is studied using three different theoretical approaches, viz: the quasi-bound state wavefunction approach (QSWA), the superasymmetric ??ssion model (SAFM) and the semiclassical approximation (QCA). The half-lives of the radioactive nuclei, calculated using these methods, are compared with each other and with available experimental data. The resonance wavefunction is obtained by numerically integrating the Schrödinger equation with outgoing boundary conditions. The sensitivity of the calculated decay widths to two particular parameter sets of the Woods-Saxon (WS) optical potentials are studied. Double folding (DF) model calculations to obtain the bare ??-nucleus potential have been carried out with the Reid M3Y effective nucleon-nucleon (NN) interactions. The exchange part of the interaction was taken to be of zero-range pseudo-potential and the density dependence of the NN interaction is accounted for. The effectiveness of the method is demonstrated using both even-even and odd-mass spherical nuclei. / Physics / MSC (PHYSICS)

Ce mémoire traite la problématique de la mobilité des sessions pour le transfert des communications multimédias basées sur le protocole SIP. Plusieurs aspects sont étudiés et des mécanismes proposés afin de permettre la mobilité des sessions avant, durant et après leur établissement. En plus d'une communication impliquant deux intervenants, Il a été possible d'étendre l'utilisation de la mobilité des sessions pour l'appliquer aux scénarios de communications en mode conférence regroupant plusieurs intervenants. Les mécanismes de mobilité de session développés au cours de cette thèse sont par la suite déployés pour (1) permettre des transformations entre différentes topologies de conférences et (2) construire un modèle de conférence adapté pour l'échange de la voix au sein des groupes de communication à large échelle.

The present research sought to understand patient experiences during Hyperbaric Oxygen Therapy (HBOT) by using 24 HBOT patients (17 men, 7 women) to examine the relationship between individual variables and anxiety, and providing One Session Exposure Therapy (OSET; Öst, 1989) if necessary. Pre-HBOT participants completed the following measures: State-Trait Anxiety Inventory (STAI; Spielberger, 1983), Claustrophobia Questionnaire (CLQ; Radomsky, Rachman, Thordarson, McIsaac, & Teachman, 2001), Anxiety Sensitivity Index (ASI; Reiss, Peterson, Gursky, & McNally, 1986), and Treatment Credibility/Expectancy Questionnaire (CEQ; Devilly & Borkovec, 2000). State Anxiety was assessed pre-HBOT and at the tenth and last sessions. Findings suggest Dispositional Anxiety (STAI-Trait + ASI), Expectancy of symptom improvement (CEQ), and gender were significantly predictive of State Anxiety before and during HBOT. Limitations and directions for future research are discussed.