Global ETD Search

1	Optimization of a Software Defined Radio multi-standard system using Graph Theory. / Théorie des graphes pour l’optimisation d’un équipement radio logicielle multi-standards Kaiser, Patricia 20 December 2012 (has links) Le concept de radio logicielle (SDR) est une solution pertinente pour concevoir des équipements multi-standards. Une façon de réaliser de tels équipements est d'identifier les fonctions et opérateurs communs entre les standards. Cette approche s’appelle la paramétrisation et est divisée en deux catégories : l'approche pragmatique qui est une version pratique pour créer et développer des opérateurs communs à partir d’opérateurs existants, et l'approche théorique dont l’objectif est de réaliser une exploration graphique d’un équipement multi-standards selon différents niveaux de granularité, accompagnée d’un problème d'optimisation. C’est cette dernière approche qui a constitué le sujet de base de cette thèse. Ainsi, une fonction de coût doit être optimisée afin de sélectionner les opérateurs communs entre les différentes normes, ce qui permet de proposer une configuration optimale à partir de laquelle sont déduits les opérateurs communs. Dans notre travail, nous avons dans un premier temps modélisé théoriquement la structure graphique d’un système multi-standards par un hypergraphe orienté. En outre, nous avons fourni une expression mathématique alternative de la fonction de coût suggérée, en utilisant des définitions propres à la théorie des graphes. Ensuite, nous avons montré que le problème d'optimisation associé était un problème NP sous une certaine contrainte, ce qui a entraîné une preuve d'exclusion de certaines configurations dont les coûts ne peuvent être minimaux. Ceci a constitué la deuxième contribution de cette thèse. Enfin, nous avons proposé un nouvel algorithme permettant de résoudre le problème d'optimisation donné, et dont l'intérêt est de donner une solution optimale du problème au lieu d’une solution approchée fournie par les méthodes heuristiques classiques. Un programme associé à cet algorithme a été développé en langage C, puis appliqué à plusieurs exemples de cas génériques afin d’en étudier les performances. / The Software-Defined Radio (SDR) concept is emerging as a potential and efficient solution for designing flexible future-proof multi-standard systems. A way of realizing a multi-standard terminal is to identify the appropriate common functions and operators inside and between the standards. This is what's called the parametrization approach, which can be divided into two categories: the pragmatic approach which is a practical version to create and develop common operators, and the theoretical approach which represents a graphical exploration of the SDR multi-standard system at different levels of granularity accompanied with an optimization problem. It’s in this last approach where our thesis subject dwells. In this context, a suggested cost function (in previous work) has to be optimized in order to select the convenient common operators between the different standards, enabling to construct an optimal design. In our work, we theoretically model a previously proposed graph structure of an SDR multi-standard system as a directed hypergraph as well as provide an alternative mathematical formal expression of the suggested cost function, using various graph theoretical definitions and notations. Afterwards, we prove that the associated optimization problem is an NP-problem under a certain constraint, which entails a proof of exclusion of some particular design options when searching for a minimum cost design. This was the second contribution in this thesis before we finally present a new algorithm (which exploits various modelization aspects of directed hypergraphs) that can solve the optimization problem, whose interest is in it giving an exact-optimal solution to our problem instead of a near-optimal one provided by heuristics. A program code for this algorithm was developed in C-language, and then it was applied on several generic case examples in order to explore its performance skills. Concept de radio logicielle Théorie des graphes Hypergraphes orientés NP Optimisation Paramétrisation Software Defined Radio Graph theoretical definitions Directed hypergraphs NP Optimization Parametrization 378.242
2	Search Strategies For Multiple Autonomous Agents Sujit, P B 10 1900 (has links) (PDF) No description available. Guided Missiles - Graph Theory Guided Missiles - Algorithms Unmanned Aerial Vehicle Aerial Vehicles - Search Strategies Bimatrix Games Unmanned Aerial Vehicles (UAVs) Graph Theoretical Model Game Theoretical Models Negotiation Schemes Astronautics
3	Modèle épidémiologique multigroupe pour la transmission de la COVID-19 dans une résidence pour personnes âgées Ndiaye, Jean François 11 1900 (has links) Dans ce mémoire, nous considérons un modèle épidémiologique multigroupe dans une population hétérogène, pour décrire la situation de l’épidémie de la COVID-19 dans une résidence pour personnes âgées. L’hétérogénéité liée ici à l’âge reflète une transmission élevée dûe à des interactions accrues, et un taux de mortalité plus élevé chez les personnes âgées. Du point de vue mathématique, nous obtenons un modèle SEIR multigroupe d’équations intégro-différentielles dans lequel nous considérons une distribution générale de la période infectieuse. Nous utilisons la méthode des fonctions de Lyapunov et une approche de la théorie des graphes pour déterminer le rôle du nombre de reproduction de base \(\mathcal{R}_0\) : l’état d’équilibre sans maladie est globalement asymptotiquement stable et l’épidémie s’éteint dans les deux groupes lorsque \(\mathcal{R}_0 \leq 1\), par contre elle persiste et l’état d’équilibre endémique est globalement asymptotiquement stable lorsque \(\mathcal{R}_0>1\). Les simulations numériques illustrent l’impact des stratégies de contrôle de la santé publique. / In this thesis, we consider a multiple group epidemiological model in a heterogeneous population to describe COVID-19 outbreaks in an elderly residential population. Age-based heterogeneity reflects higher transmission with enhanced interactions, and higher fatality rates in the elderly. Mathematically, we analyse a SEIR model in the form of a system of integro-differential equations with general distribution function for the infectious period. Lyapunov functions and graph-theoretical methods are employed to establish the role played by the basic reproduction ratio \(\mathcal{R}_0\) : global asymptotic stability of the disease-free equilibrium and no sustained outbreak when \(\mathcal{R}_0 \leq 1\), as opposed to persistent outbreak and globally asymptotic endemic equilibrium when \(\mathcal{R}_0>1\). Numerical simulations are presented to illustrate public health control strategies. Modèle épidémiologique SEIR Multigroupe COVID-19 Equations intégro-différentielles Fonctions de Lyapunov Théorie des graphes Stabilité globale asymptotique Simulations numériques Epidemiological SEIR model Multiple group Integrodifferential equations Lyapunov fonctions Graph-theoretical Basic reproduction ratio R0 Global asymptotic stability Numerical simulations
4	Action in Chronic Fatigue Syndrome: an Enactive Psycho-phenomenological and Semiotic Analysis of Thirty New Zealand Women's Experiences of Suffering and Recovery Hart, M J Alexandra January 2010 (has links) This research into Chronic Fatigue Syndrome (CFS) presents the results of 60 first-person psycho-phenomenological interviews with 30 New Zealand women. The participants were recruited from the Canterbury and Wellington regions, 10 had recovered. Taking a non-dual, non-reductive embodied approach, the phenomenological data was analysed semiotically, using a graph-theoretical cluster analysis to elucidate the large number of resulting categories, and interpreted through the enactive approach to cognitive science. The initial result of the analysis is a comprehensive exploration of the experience of CFS which develops subject-specific categories of experience and explores the relation of the illness to universal categories of experience, including self, ‘energy’, action, and being-able-to-do. Transformations of the self surrounding being-able-to-do and not-being-able-to-do were shown to elucidate the illness process. It is proposed that the concept ‘energy’ in the participants’ discourse is equivalent to the Mahayana Buddhist concept of ‘contact’. This characterises CFS as a breakdown of contact. Narrative content from the recovered interviewees reflects a reestablishment of contact. The hypothesis that CFS is a disorder of action is investigated in detail. A general model for the phenomenology and functional architecture of action is proposed. This model is a recursive loop involving felt meaning, contact, action, and perception and appears to be phenomenologically supported. It is proposed that the CFS illness process is a dynamical decompensation of the subject’s action loop caused by a breakdown in the process of contact. On this basis, a new interpretation of neurological findings in relation to CFS becomes possible. A neurological phenomenon that correlates with the illness and involves a brain region that has a similar structure to the action model’s recursive loop is identified in previous research results and compared with the action model and the results of this research. This correspondence may identify the brain regions involved in the illness process, which may provide an objective diagnostic test for the condition and approaches to treatment. The implications of this model for cognitive science and CFS should be investigated through neurophenomenological research since the model stands to shed considerable light on the nature of consciousness, contact and agency. Phenomenologically based treatments are proposed, along with suggestions for future research on CFS. The research may clarify the diagnostic criteria for CFS and guide management and treatment programmes, particularly multidimensional and interdisciplinary approaches. Category theory is proposed as a foundation for a mathematisation of phenomenology. action Chronic Fatigue Syndrome Myalgic Encephalomyelitis Chronic Immune Deficiency Syndrome enaction social enaction social enactivism enactive psycho-phenomenological psychophenomenological vipassana groundlessness mind-body korper leib co-generative Focusing co-creative environment Antonio Damasio reciprocal constraints Pierre Vermersch Claire Petitmengin Antione Lutz narrative discourse phenomenal invariants Evan Thompson Merleau-Ponty Algirdis Julien Greimas Husserl first-person Fransisco Varela modelling invariants Natalie Depraz isotope John Boyd OODA loop Jonathan Shear Shaun Gallagher Arthur Kleinman Humberto Maturana second-person Alva Noe Dan Zahavi stages Embodied Mind Canterbury Wellington New Zealand non-dual non-reductive embodied phenomenological third-person graph-theoretical cluster analysis cognitive science experience solution subject-specific categories universal categories universal categories self energy illness process intersubjectivity Mahayana Buddhism contact narrative recovered making sense recursive loop perception dynamical decompensation neurology diagnosis empathy treatment management neurophenomenological neurophenomenology consciousness veracity agency multidimensional interdisciplinary category theory enculturation mathematisation of phenomenology interview nomenclature diagnostic criteria incidence prevalence coping strategy etiology epidemiology psychosomatic medicine meaning women girl female anthropology sociology cognitive behavioral therapy exercise therapy recovery mindful awareness suffering symbolisation Prasangika no-self aggregates wheel of karma cognition basic element analysis mental factors operational closure stereotypes enactive ontologically fragile self grief process-knowledge epoche phenomenal invariants textual invariants compound meaning saturation formalisation cluster analysis inter-session review inter-individual validation explicitation interview intricacy confidence psychophenomenology self-esteem sanction self dis-integration permanence continuity ego-self emotion surrender semiotic square meditation empathy semiotic compassion existential feelings goal obstruction movement transformation change somatic Giovanna Colombetti agoraphobia panic anxiety psychotherapy sleep rest pain weakness strength stamina Diego Cosmelli heaviness food chemicals allergy recovering despair frustration helplessness fear efference valence afference as-if-body-loop consciousness representation attention recovery intention sustainable sustainability neurasthenia existential feelings asthenia hysteria mononucleosis samatha-vispasnya prajna vijnana Eugene Gendlin Abhidharma dukkha shamatha interdependence vipashyana

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