La présente thèse s'intéresse à l'évolution d'organisations à caractère démocratique ou ouvert, au travers de leur stabilité ainsi que d'autres caractéristiques comme leur capacité à fédérer, à satisfaire leurs membres ou pérenniser des situations de partage de risque entre agents hétérogènes. Les modèles proposés sont des modèles agents qui s'appuient sur une étude menée depuis 2004 par Juliette Rouchier sur les circuits courts agroalimentaires et particulièrement sur les Associations pour le Maintien d'une Agriculture Paysanne (AMAP) et leur structuration en réseaux d'AMAP à différentes échelles géographiques. La thèse suggère l'existence d'une tension entre la stabilité et la représentativité dans ce type d'organisations démocratiques et discute, dans plusieurs cas de figure, l'impact de différents facteurs sur cette tension comme le nombre de sujets discutés dans l'organisation, l'état d'esprit des membres, l'existence d'une communication structurée au sein de l'organisation, ou encore la répartition géographique des membres. Dans un second temps la thèse s'intéresse à des groupes de partage de risque entre agents hétérogènes, comme c'est le cas dans les AMAP entre producteurs et consommateurs. Elle suggère que l'apprentissage par les agents de leurs risques, c'est à dire de leurs préférences vis-à-vis des caractéristiques de leur organisation au cours du temps, pérennise un partage de risque complet entre des agents hétérogènes. De plus cet effet semble renforcé par l'introduction de préférences pour autrui, comme l'altruisme ou l'aversion aux inégalités. / This PhD thesis studies the evolution of organizations under democratic settings through their stability along with other characteristics like their representativeness, their capacity to satisfy their members or to ensure risk sharing agreement between heterogenous agents. Proposed models are agent based models grounded in a study, initiated by Juliette Rouchier in 2004, on short food chains and particularly on "Associations pour le Maintien d'une Agriculture Paysanne" (AMAP), the french equivalent of United States' Community Supported Agriculture (CSA) along with their structuration in AMAP' networks at different geographical levels. This PhD thesis suggests the existence of a tension between stability and representativeness under democratic settings and discusses, in different cases, the effect of several factors on this tension, like the number of topics discussed in the organization, the state of mind of members, the existence of structured communication, or the spatial repartition of members. In a second part, this Phd thesis deals with risk sharing groups between agents heterogenous in terms of risk exposures, as it is the case in AMAP between producers and consumers. It underlines how learning by agents of their risk exposures through times, which is equivalent here to constantly revise their preferences with respect to the characteristics of their organization, can stabilize risk-sharing groups mixing heterogenous agents and how this effect is strengthen by the introduction of other-regarding-preferences, like altruism or inequality aversion.

Submitted by MARCIA ROVADOSCHI (marciar@unifra.br) on 2018-08-20T12:59:30Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_AlexandredeOliveiraZamberlan.pdf: 14214019 bytes, checksum: cdd28b0c541b52994e91cbeb4ec0c2fe (MD5) / Made available in DSpace on 2018-08-20T12:59:31Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_AlexandredeOliveiraZamberlan.pdf: 14214019 bytes, checksum: cdd28b0c541b52994e91cbeb4ec0c2fe (MD5) Previous issue date: 2018-03-23 / Production and characterization of polymer nanoparticles (PNPs), colloidal dispersions, are processes that require time and technical skills to produce accurate results. Computational simulations in Nanoscience have aided in these processes, providing support and agility to achieve better results. In this work, the challenge was to show, previously, by computational simulation, the agglomeration behavior, which indicates instability in a nanoparticulate system. These PNPs are used for transport and delivery of drugs in various treatments. The Computing area has methods based on behaviors derived from nature, such as systems of intelligent collective behavior or MAS. Such systems are composed of agents - programs - living in society, which interact with each other. This approach facilitates the implementation of real systems that require observation of specific behavior, since each agent can be programmed individually to perceive other agents, the environment and respond to these perceptions so that the behavior of the system arises from the interactions of these agents agents. Thus, the objective of the work was to evaluate the agglomeration effect of polymer nanoparticles (PNPs) through design, implementation and testing of the simulation environment using MAS theory. The methodology used was computer simulation supported by a case study. For the case study, a simulation environment was constructed with functionalities to produce interactions between particles from physical-chemical parameters, that guarantee the Brownian movement with elastic and inelastic collisions. This environment, named "Multi-Agent System for Polymeric Nanoparticles" (MASPN), has been developed according to the Feature Driven Development (FDD) methodology of software design and the methodology of Multi-Agent Systems. In addition, we used the event-oriented simulation package algs4 and the JASON agent building environment, all integrated by Java technology. The package has implementations of various functions for scientific computing and event-oriented simulation, including resolution of particle-particle and particle-wall collisions, obeying the stochastic model of Brownian motion. The MASPN environment emerges as the main result of this research, since it is an alternative simulation tool, containing graphical interface with integrated physicochemical parameters, distribution graphs (particle size, particle zeta potential and environment pH), particle animation under the Brownian mathematical model.The parameters of the simulations, for evaluation of the agglomeration effect, are size, size distribution, surface electric charge, mass, drug content and pH. Finally, the simulation environment designed and built, integrating areas, methodologies and technologies, can be considered a resource in the production and characterization of polymer nanoparticles, since the simulations performed had significantly accurate results. In addition, we can be stated that scientifically this research provides perspectives of future work in Pharmacy, Chemistry, Physics and/or Computing. / Produção e caracterização de nanopartículas poliméricas (NPPs), dispersões coloidais, são processos que exigem tempo e habilidades técnicas para produzir resultados precisos. Simulações computacionais em Nanociência têm auxiliado nesses processos, fornecendo suporte e agilidade para alcançar melhores resultados. Neste trabalho, o desafio foi mostrar, previamente, por simulação computacional, o comportamento de aglomeração, que pode indicar instabilidade em um sistema nanoparticulado. As NPPs podem ser utilizadas para transporte e entrega de fármacos em diversos tratamentos. A área da Computação possui métodos baseados em comportamentos advindos da natureza, como sistemas de comportamento coletivo inteligente ou Sistemas Multi-agentes (SMA). O uso dessa abordagem facilita a implementação de sistemas reais que necessitam de observação de comportamento específico, pois se pode programar individualmente cada agente para que perceba outros agentes, o ambiente e responda a essas percepções de forma que o comportamento do sistema observado surja a partir das interações desses agentes. Dessa forma, o objetivo do trabalho foi avaliar o efeito de aglomeração de nanopartículas poliméricas, por meio de projeto, implementação e testes de um ambiente de simulação com o uso da abordagem SMA. A metodologia de pesquisa empregada foi simulação computacional amparada por estudo de caso, em que foi construído um ambiente de simulação com funcionalidades de produzir interações entre partículas a partir de um conjunto reduzido de parâmetros físico-químicos, que garantam o movimento Browniano, relacionado ao modelo estocástico, que muitas vezes é chamado de teoria da partícula. O ambiente, nominado de Multi-Agent System for Polymeric Nanoparticles (MASPN), vem sendo desenvolvido de acordo com a metodologia Feature Driven Development (FDD) de projeto de software e a metodologia de Sistemas Multiagentes. Também, foram utilizados o pacote de simulação orientada a eventos algs4 e o ambiente de construção de agentes JASON, todos integrados pela tecnologia Java. Sendo assim, o ambiente MASPN surge como o principal resultado desta investigação, pois é uma ferramenta de simulação alternativa, contendo interface gráfica com parâmetros físico-químicos integrados, gráficos de distribuição e animação de partículas sob o modelo matemático de partícula. Os parâmetros tratados nas simulações são diâmetro, distribuição de tamanho, carga elétrica de superfície, massa, teor do fármaco e pH. Finalmente, o ambiente de simulação proposto com a integração de áreas, metodologias e tecnologias pode ser considerado um recurso na produção e na caracterização de nanopartículas poliméricas, uma vez que as simulações executadas no MASPN e relatadas neste trabalho tiveram resultados significativamente positivos. Além disso, pode-se afirmar que cientificamente esta investigação proporciona perspectivas de trabalhos futuros tanto na Farmácia, Química, Física quanto na Computação.