Cette thèse est consacrée à l'étude des micro-miroirs déformables pour l'optique adaptative. Les miroirs déformables actuels montrant aujourd'hui leurs limites en terme de nombre d'actionneurs et d'espace inter-actionneurs, une nouvelle classe de miroir doit être développée. En plus de satisfaire des spécifications actuelles requerrant entre autres une course de dix microns, une réponse linéaire et une bande passante supérieure au kilohertz, ces miroirs déformables devront aussi être compacts et comporter plusieurs milliers d'actionneurs. L'originalité de notre approche tient en la réalisation, en collaboration avec le Laboratoire d'Analyse et d'Architecture des Systèmes, de micro-miroirs déformables basés sur la technologie des MOEMS et en l'élaboration de couches sacrificielles et structurales en matériau Polymère.<br />Des moyens de modélisation et de caractérisation sont mis en œuvre pour comprendre le comportement de tels composants. Un banc de caractérisation interférométrique est développé afin d'étudier des composants dont les dimensions varient de la dizaine de microns à vingt millimètres. Les mesures de la qualité optique et du comportement électro-mécanique sont menées à bien en travaillant avec l'interférométrie à décalage de phase dont la résolution est inférieure au nanomètre. L'analyse dynamique incluant les modes de vibration et les fréquences de coupure, est effectuée avec l'interférométrie moyennée dans le temps.<br />Un prototype de micro-miroir déformable a été fabriqué dans une fonderie externe. Celui-ci comporte 9 actionneurs dont la course mesurée est de 350 nm. Cette valeur est trop faible pour générer les déformations dont nous avons besoin. En revanche, l'utilisation pour la première fois du procédé polymère a permis d'élaborer un actionneur permettant une course de 2 microns pour 30 V, confirmant les choix effectués jusqu'ici. Une électronique a été conçue et réalisée afin de rendre linéaire la réponse électrostatique de ces composants. Des simulations préliminaires montrent un bon accord avec les résultats expérimentaux. La conception de micro-miroirs déformables en polymère apparaît donc comme une voie prometteuse.

Cette thèse s'intéresse aux réseaux bayésiens, aux filtres particulaires et à leur application aux communications numériques. Tout d'abord, nous donnons une construction rigoureuse et très générale des réseaux bayésiens et nous présentons l'algorithme de propagation de croyance dans ce contexte. Puis, nous introduisons un nouveau type de filtre particulaire, appelé "filtre particulaire à échantillonnage global", et nous constatons en effectuant des simulations numériques que ce nouvel algorithme se compare favorablement à l'état de l'art. Nous utilisons ensuite le filtrage particulaire pour calculer de façon approchée certains messages de l'algorithme de propagation de croyance. Nous obtenons ainsi un nouvel algorithme, combinant propagation de croyance et filtrage particulaire, que nous avons appelé "algorithme de turbo-filtrage particulaire». Enfin, nous utilisons ces différentes techniques afin de concevoir de façon méthodique un récepteur de communications numériques.

Neste trabalho é pesquisada a aplicação de um controlador adaptativo auto-ajustável multivariável à instalação propulsora de um navio com motor Diesel e hélice de passo variável. Os sistemas convencionais de controle de propulsão marítima são projetados deterministicamente e, geralmente, baseados na condição nominal de operação da embarcação, definida pelo seu deslocamento de projeto, estado de mar e de casco. Entretanto, o navio raramente opera na sua condição nominal, já que o seu deslocamento não é sempre o mesmo e continuamente ocorrem variações no estado do casco e do mar. Adicionalmente deve-se mencionar o efeito de perturbações estocásticas como vento, ondas e corrente que atuam sobre o navio. Estas considerações sugerem que o controlador de uma instalação propulsora deva ser adaptativo, isto é , que os seus ganhos se ajustem às alterações que ocorrem no sistema ou no meio ambiente. A teoria do controlador adaptativo auto-ajustável empregada neste trabalho é desenvolvida para sistemas multivariáveis lineares estocásticos, descritos por uma equação vetorial de diferenças com coeficientes desconhecidos. A lei de controle é obtida a partir da minimização de um índice de desempenho onde são ponderados os vetores de saída, de referência e de controle. A aplicação do controlador auto-ajustável exige a estimação de parâmetros do modelo. Neste trabalho é utilizado o modo implícito, que estima diretamente os parâmetros do controlador, através do método dos mínimos quadrados recursivo. Para adequar a aplicação da teoria a um sistema não linear, que é o caso da instalação propulsora, é introduzido no algorítimo de estimação de parâmetros um fator de esquecimento variável para alterar a velocidade de convergência dos parâmetros.O desempenho do controlador auto-ajustável é verificado através de uma série de testes de simulação, envolvendo manobras de regulação e de traqueamento. Com estes testes é analisada também a influência da matriz do ruído, do tempo de processamento do controlador, da matriz de ponderação do vetor de controle, da condição inicial da matriz de parâmetros, do intervalo de amostragem e da condição de operação do sistema sobre o desempenho do controlador. Os resultados de cada manobra são comparados com os obtidos com um controlador convencional projetado especificamente para o navio considerado, constatando-se o bom desempenho do controlador auto-ajustável. / This work is concerned with the application of multivariable self-tuning controllers to diesel engine propulsion plant with variable pitch propeller. Conventional control systems for marine propulsion plants are designed employing deterministic criteria based on the ship\'s operating condition, which is defined by the design displacement, sea state and hull roughness. However, only seldom if ever will the ship find itself operating in such nominal condition since her displacement is not always the same and the sea state and hull roughness vary continuously with time. In addition one should take into consideration the effect on the ship of stochastic factors such as winds, waves and sea currents. The preceding considerations suggest that the controller for a marine propulsion plant should be capable of adjusting itself to varying operating conditions. In other words, it should be capable of tuning its gains according to alterations occurring within the system or imposed by the environment. The theory of self-tuning controller employed in this work has been developed for stochastic multivariable linear systems describe by a linear vector difference equation with unknown parameters. The control law is obtained by the minimization of one performance index in which are weighted the output, reference and control vectors. The application of the self-tuning controller requires the estimation of the model parameters. In this work the implicit way is used wich directly estimates the parameters of the controller by means of the recursive minimum least-square algorithm. In order to apply the theory to non-linear systems such as propulsion plants, a variable forgetting factor is introduced in the estimation algorithm to change the convergence speed of the parameters. The performance of the self-tuning controller is assessed by means of several simulations tests involving regulating and tracking maneuvers.The tests also assess the influence on the controller performance of such factors as the noise matrix, controller process time, initial condition of parameters matrix, sampling time and operating condition of the system. The results of each maneuver are compared with those obtained by a conventional controller specifically designed for the ship under consideration and it was verified that the self-tuning controller has a good performance.

[pt] Para cruzamentos de veículos isolados, apresenta-se aqui uma lógica de controle dos tempos de passagem das fases de veículos, que tenta otimizar a utilização do tempo disponível em cada ciclo, adaptando-se as necessidades reais de cada fase do cruzamento. Este procedimento de controle permite detetar o congestionamento do cruzamento em caso de se apresentar tal situação. Também, este trabalho contém o projeto de um controlador de sinais de trânsito baseado em um microcomputador, que emprega a lógica de controle proposta. O controlador pode se ajustar através do painel de controle, para dirigir cruzamentos que tenham desde duas até cinco fases de veículos, com a possibilidade de incluir como uma fase adicional, o serviço de passagem de pedestres. / [en] For the use in isolated veicular intersections, here is presented a logic for control of the time in veicular phases that tends to optimise the cicle time, based on the specific necessites of each phase. With this control`s producere it is possible to detect a veicular congestion at the intersection. In this paper it is also presented the desing of a microcomputer based traffic signal controller wich implements the control logic proposed. The controller can work at intersections that have from two to five veicular`s phases and has also the possibility to include a pedestrian phase, by setting those conditions in the control panel.

La grande majorité des plantes à fleurs se reproduisent grâce à leurs pollinisateurs. L’évolution chez les plantes est pourtant souvent étudiée sans prendre en compte ces interactions, et cette thèse vise à mieux comprendre leur impact sur l’évolution des plantes. Dans un premier chapitre, je présenterai les effets connus des pollinisateurs sur le taux d’autofécondation des plantes et sur son évolution. Dans un second chapitre, j’ai modélisé l’évolution du taux d’autofécondation des plantes lorsque celui-ci affecte la démographie des plantes et des pollinisateurs, et l’investissement des plantes dans la pollinisation. Cette étude montre que l’évolution vers l’autofécondation peut mener à l’extinction des plantes. Dans un troisième chapitre, je m’intéresserai à l’évolution des caractéristiques florales pour des espèces qui dépendent obligatoirement du transfert de pollen entre individus : les espèces dioïques. Cette étude montre que l’attractivité des plantes peut évoluer différemment chez les individus mâles et femelles, surtout dans les grandes populations qui subissent peu de limitation en pollen. Ce résultat suggère que le dimorphisme sexuel ne menacerait pas le maintien des populations dioïques. Enfin, même si elles prennent en compte les pollinisateurs de manière sommaire, les études précédentes ont montré leur importance pour la démographie et l’évolution chez les plantes. La dernière étude de cette thèse a donc pour but de mieux décrire et quantifier les mécanismes sous-jacents au comportement du pollinisateur, en particulier concernant l’impact des traits floraux. Elle permettra une meilleure intégration des interactions plantes-pollinisateurs dans les modèles. / The mode of pollination is often neglected regarding the evolution of plant traits, although the reproduction of most flowering plants is based on their interactions with pollinators. This thesis aims at a better understanding of the interplay between animal-pollination and the evolution of plant traits. First, I will present a detailed review on the interplay between plant mating system and pollinator behavior, which highlights the impact of pollinators on the immediate ecological selfing rate and on its evolution. Second, I modeled the evolution of plant selfing rate when it affects both the demography of plants and pollinators and the investment of plants in pollination. This study provides new theoretical evidence that evolution towards selfing can lead to an evolutionary suicide in some conditions. Third, I will present a modeling analysis of the impact of animal-pollination for species that compulsorily rely on outcross pollination: entomophilous dioecious species. This study revealed that under pollinator-mediated selection, attractiveness of males and females should evolve in large populations that do not suffer from pollen limitation. This result suggests that dimorphism may not be a threat for dioecious populations. Finally, although the previous models integrated pollinators in a basic way, they highlighted strong interplays between pollinators, plant demography, and the evolution of plant traits. The last study of this thesis, aims at defining and quantifying the mechanisms underlying pollinator foraging behavior, and especially the impact of plants floral traits on pollen transfer. This would allow for a better modeling of plant-pollinators interactions.

Em habilidades como o nadar tem se creditado o sucesso à consistência do comportamento, negligenciando o papel da flexibilidade. Nesse sentido, com o objetivo de investigar o efeito da modificação da tarefa na braçada do nado crawl em indivíduos em níveis de habilidades distintos, partiu-se da visão de complementaridade entre consistência e flexibilidade do comportamento motor habilidoso. Crianças (42), com média de 8,7 anos de idade, com domínio do nado crawl, participaram do experimento. Usando o instrumento de análise do nível de proficiência do nado crawl, dois grupos, de 15 sujeitos cada, em níveis de habilidades distintos foram formados. Medidas de aspectos invariantes e variantes foram utilizadas para analisar as braçadas na tarefa de deslocar-se 30 metros em três velocidades. Segundo os resultados, os nadadores mantiveram a organização temporal da braçada (OTB) nas três condições experimentais; o grupo mais habilidoso (+H) apresentou a OTB mais estável; e, as alterações de desempenho foram efetuadas, exclusivamente a partir de ajustes dos aspectos variantes das braçadas. Em função dos resultados conclui-se que a aquisição do nadar, vista como um processo contínuo, envolve a formação de representações mentais que asseguram tanto a consistência (aspectos invariantes) como a flexibilidade (aspectos variantes) da braçada e, que sua complexidade está associada ao nível de habilidade dos nadadores. / In skills, as swimming, there has been credit to the success of the consistency of behaviour neglecting the role of flexibility. In this way with the objective of investigating the effect of the modification of the task in the front crawl stroke in individuals with distinct levels of skill we launched from the point that consistency and flexibility complement each other in the skilful motor behaviour. Children (42), with an average age of 8.7 with the skill of swimming crawl participated in the experiment. Using the analysis instrument of proficiency level of the crawl style, two groups of 15 subjects each, with distinct levels of ability were formed. Measures of variant and invariant aspects were used to analyze the stroke of drifting 30 meters in three velocities. According to the results the swimmers maintained the temporal organization of the stroke (TOS) in three experimental conditions; the more skilful group presented the more stable TOS; and the alterations of the performance were made exclusively from the adjustments of the variant aspects of the strokes. Due to the results it was concluded that the acquisition of swimming seen as a continuous process, involves the formation of mental representations that assure not only consistency (invariant aspects) but also the flexibility (variaant aspects) of the stroke and that its complexity is associated to the level of skill in the swimmers.

Over the past decades, wolverines in Sweden have made a recovery from near extinction to recolonization large part of their historic range. Effective conservation of large carnivores, which inhabit extensive territories, necessitates adaptative management that considers the diverse ecological and societal factors spanning their entire range. This report contributes to our understanding of wolverines in the southern periphery of their recolonized area, focusing on their scavenging behaviour. I utilize data from 14 wolverines, tracked with GPS-collars in Värmland, Dalarna and Jämtland over five years (2018-2022). The monitoring covered 19 three-week periods, during spring, early summer, and autumn. My thesis focusses on the wolverine’s utilization of two type of scavenging sites: anthropogenic food resources and carcasses from wild ungulates. The results show that females exhibit higher visit frequencies to both types of scavenging sites during spring and summer, but this difference diminishes in autumn when males visit scavenging sites more frequently than in other seasons. Anthropogenic feeding sites had more visits during autumn, compared to wild carcasses, whereas wild carcasses are more commonly utilized in spring and summer. The presence of large predators influences wolverine scavenging behavior, as evidenced by shorter visits to feeding sites in Jämtland (with high bear density) compared to Värmland and Dalarna. Nevertheless, these low-conflict areas have all benefited wolverines by increasing their reproductive rate, offering hope for the ongoing recolonization. Moreover, my results show that human activities in this region can have a positive impact on wolverines, by acting as and apex predator providing a stable food source, which should further facilitate recolonization success.

[pt] Este estudo tem por objetivo contribuir para emprego de antenas adaptativas em sistemas de comunicação sem fio. É feita uma revisão dos métodos de estimação de ângulo de chegada e de sua utilização na formação de feixe. O desempenho de alguns métodos baseados em subspace fitting é comparado através de simulação considerando quatro cenários. O primeiro supões apenas a presença de ruído. Os demais consideram os modelos típicos de espalhamento local, ou seja, espalhamento aleatório dos ângulos de chegada. / [en] This work intends to contribute for the employment of the Adaptive Antennas in Wireless Communications. In this way, a review of methods for direction of arrival estimation and beamforming is presented. The performance of some subspace fitting direction of arrival estimation methods is evaluated by simulation considering four propagation scenarios: The first assumes only additive white Gaussian noise; The three others consider typical models for local scattering, which means a random angular spread of angle of arrival.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

L’objectif de la recherche a été de tester la pertinence de 10 attributs de comportement social des fondateurs-dirigeants de start-up de biotechnologie issus de l’observation des conduites des animaux sociaux (Wilson, Sociobiology, 1975). A travers 25 entretiens approfondis reprenant l’expérience des fondateurs-dirigeants et leur évaluation des facteurs contributifs à leur succès managérial sur les critères de Wilson, nous mettons en évidence des références constantes à la biologie évolutionniste qui permettent de mieux comprendre les éléments déterminants de socialisation et de gouvernance des start-ups de biotechnologie. Toutes les références des dirigeants créant des analogies entre biologie cellulaire et moléculaire et entreprise sont recensées pour proposer une interprétation de la firme comme un organisme vivant. Notre travail propose des pistes en matière de développement des organisations et de développement personnel issues de trois attributs sociobiologiques particulièrement explicites dans le milieu managérial : la cohésion, la connectivité et la démographie adaptive. L’échantillonnage restreint aux start-ups de biotechnologie ne permet pas d’inférer des généralisations à toutes les nouvelles entreprises, comme dans le secteur digital, mais permet de penser que les conduites managériales des fondateurs-dirigeants pourraient avoir des points communs. Les implications de nos résultats peuvent conduire à réexaminer les principes de constitution des équipes dirigeantes des start-ups pour obtenir une meilleure efficacité du leadership grâce à une socialisation efficace. / The research aimed at testing the relevance of 10 attributes of social managerial behavior by founding Managing Directors of young biotech companies. These attributes are sourced from observation of social animals (Wilson, Sociobiology, 1975). With the help of 25 in-depth face-to-face interviews with CEO probing their managerial experience and evaluation of the relevance of Wilson’s criteria upon their success, wedemonstrate the constant reference to evolutionary biology allowing a goodunderstanding of successful leadership and governance of biotech start-ups. All references by CEO to analogies between cell and molecular biology and companiesare listed, supporting the comparison of the firm with living organisms. Our work suggests directions for organizational and personal development arising fromthree key sociobiological attributes of noticeable importance in management: cohesion,connectivity, adaptive demography. Sampling restrained to biotech companies does notallow for extension to all young companies, but provides interesting insights intomanagement behavior by all founding CEO. Our results may help reexamine how CEO are creating and managing their teams for abetter collective efficacy.