Graphene is a candidate for next generation spintronics devices exploiting its long spin transport length and high carrier mobility. Besides, when put in interaction with a ferromagnet, it may become an active building block, as suggested by recent surface science studies revealing few tenth of a Bohr magneton magnetic moments held by carbon atoms in graphene on iron, and a Rashba spin-orbit splitting reaching about 10 meV in graphene on a high atomic number element such as gold. The extent to which graphene may influence the properties, e.g. magnetic ones, of the materials contacted to it was barely addressed thus far. High quality hybrid systems composed of graphene in contact with magnetic thin layers or nanoclusters are playgrounds for exploring both aspects, the manipulation of the properties of graphene by interaction with other species, and vice versa. In graphene contacted to ultra-thin ferromagnetic layers for instance, strong graphene/ferromagnet interface effects could be employed in the view of manipulating the magnetization in the ferromagnet. The recently discovered close-to-perfect self-organization of nanoclusters on graphene, provides a way to probe magnetic interaction between clusters, possibly mediated by graphene. Three high quality hybrid systems relying on graphene prepared by chemical vapor deposition on the (111) surface of iridium have been developed under ultra-high vacuum (UHV): cobalt ultra-thin and flat films deposited on top of graphene, and intercalated at moderate temperature between graphene and its substrate, and self-organized cobalt- and iron-rich nanoclusters on the 2.5 nm-periodicity moiré between graphene and Ir(111). Prior to these systems, 10 nm-thick Ir(111) single-crystal thin films on sapphire were developed: they were latter employed as a substrate replacing bulk Ir(111) single-crystals usually employed. This new substrate opens the route to multi-technique characterizations, especially ex situ ones which were little employed thus far for studying graphene/metal systems prepared under UHV. Using a combination of in situ surface science techniques (scanning tunneling microscopy, x-ray magnetic circular dichroism, spin-polarized low-energy electron microscopy, auger electron spectroscopy, reflection high-energy electron diffraction) and ex situ probes (x-ray diffraction, transmission electron microscopy, Raman spectroscopy, MOKE magnetometry) the structural, vibrational, electronic, and magnetic properties of the three new graphene hybrid systems were characterized and confronted to first-principle calculations. Several striking features were unveiled. The interface between graphene and cobalt involves strong C-Co interactions which are responsible for a large interface magnetic anisotropy, capable of driving the magnetization out-of-the plane of the surface of an ultra-thin film in spite of the strong shape anisotropy in such films. The effect is maximized in the system obtained by intercalation between graphene and iridium, which comes naturally air-protected. Nanoclusters, on the contrary, seem to weakly interact with graphene. Small ones, comprising ca. 30 atoms each, remain super paramagnetic at 10 K, have no magnetic anisotropy, and it turns out difficult, even with 5 T fields to saturate their magnetization. Besides, the magnetic domains size seem to exceed the size of a single cluster, possibly pointing to magnetic interactions between clusters.

Graphène est un candidat pour la préparation de dispositifs spintroniques de nouvelle génération tirant partie de sa grande longueur de diffusion de spin et de la grande mobilité de ses porteurs de charge. En interagissant avec matériau ferromagnétique, il pourrait en outre devenir un élément actif, comme le suggèrent des études récentes par physique des surfaces, qui mettent en évidence un moment magnétique de quelques fractions de magnéton de Bohr dans le graphène en contact avec du fer, et une séparation en spin des bandes électroniques du graphène, d'environ 10 meV, par un effet Rashba au contact d'un élément de grand numéro atomique (l'or). La façon dont le graphène peut influencer les propriétés, par exemple magnétiques, des matériaux qui y sont contactés, reste peu étudiée. Les systèmes hybrides de haute qualité, constitués de graphène en contact avec des couches minces magnétiques ou des plots de taille nanométrique, sont des terrains de jeu pour explorer les deux aspects, la manipulation des propriétés du graphène par son interaction avec d'autres espèces, et vice versa. Dans le graphène contacté à des couches magnétiques ultra-minces par exemple, de forts effets d'interface pourraient être exploités pour contrôler l'aimantation du matériau magnétique. L'auto-organisation quasi-parfaite récemment découverte pour des plots nanométriques sur graphène, pourrait permettre d'explorer les interactions magnétiques, potentiellement transmises par le graphène, entre plots. Trois systèmes hybrides de haute qualité, intégrant du graphène préparé par dépôt chimique en phase vapeur sur le surface (111) de l'iridium, ont été développés sous ultra-haut vide (UHV) : des films ultra-minces de cobalt déposés sur graphène, et intercalés à température modérée entre graphène et son substrat, ainsi que des plots nanométriques riches-Co et -Fe, organisés avec une période de 2.5 nm sur le moiré entre graphène et Ir(111). Auparavant, des films de 10 nm d'Ir(111), monocristallins, déposés sur saphir, ont été développés. Ces films ont été par la suite utilisés comme substrats en remplacement de monocristaux massifs d'Ir(111). Ces nouveaux substrats ont ouvert la voie à des caractérisations multi-techniques ex situ, peu utilisées jusqu'alors pour étudier les systèmes graphène/métaux préparés sous UHV. Au moyen d'une combinaison de techniques de surface in situ et de sondes ex situ, les propriétés structurales, vibrationnelles, électroniques et magnétiques des trois nouveaux systèmes hybrides ont été caractérisées et confrontées à des calculs ab initio. Un certain nombre de propriétés remarquables ont été mises en évidence. L'interface entre graphene et cobalt implique de fortes interactions C-Co qui conduisent à une forte anisotropie magnétique d'interface, capable de pousser l'aimantation hors de la surface d'un film ultra-mince en dépit de la forte anisotropie de forme dans ces films. Cet effet est optimum dans les systèmes obtenus par intercalation entre graphène et iridium, qui sont par ailleurs naturellement protégés des pollutions de l'air. Les plots nanométriques, au contraire, semblent peu interagit avec le graphène. Des plots comprenant environ 30 atomes restent superparamagnétiques à 10 K, n'ont pas d'anisotropie magnétique, et leur aimantation est difficile à saturer, même sous 5 T. D'autre part, la taille des domaines magnétiques semble dépasser celle d'un plot unique, ce qui pourrait être le signe d'interactions magnétiques entre plots. / Graphene is a candidate for next generation spintronics devices exploiting its long spin transport length and high carrier mobility. Besides, when put in interaction with a ferromagnet, it may become an active building block, as suggested by recent surface science studies revealing few tenth of a Bohr magneton magnetic moments held by carbon atoms in graphene on iron, and a Rashba spin-orbit splitting reaching about 10 meV in graphene on a high atomic number element such as gold. The extent to which graphene may influence the properties, e.g. magnetic ones, of the materials contacted to it was barely addressed thus far. High quality hybrid systems composed of graphene in contact with magnetic thin layers or nanoclusters are playgrounds for exploring both aspects, the manipulation of the properties of graphene by interaction with other species, and vice versa. In graphene contacted to ultra-thin ferromagnetic layers for instance, strong graphene/ferromagnet interface effects could be employed in the view of manipulating the magnetization in the ferromagnet. The recently discovered close-to-perfect self-organization of nanoclusters on graphene, provides a way to probe magnetic interaction between clusters, possibly mediated by graphene. Three high quality hybrid systems relying on graphene prepared by chemical vapor deposition on the (111) surface of iridium have been developed under ultra-high vacuum (UHV): cobalt ultra-thin and flat films deposited on top of graphene, and intercalated at moderate temperature between graphene and its substrate, and self-organized cobalt- and iron-rich nanoclusters on the 2.5 nm-periodicity moiré between graphene and Ir(111). Prior to these systems, 10 nm-thick Ir(111) single-crystal thin films on sapphire were developed: they were latter employed as a substrate replacing bulk Ir(111) single-crystals usually employed. This new substrate opens the route to multi-technique characterizations, especially ex situ ones which were little employed thus far for studying graphene/metal systems prepared under UHV. Using a combination of in situ surface science techniques (scanning tunneling microscopy, x-ray magnetic circular dichroism, spin-polarized low-energy electron microscopy, auger electron spectroscopy, reflection high-energy electron diffraction) and ex situ probes (x-ray diffraction, transmission electron microscopy, Raman spectroscopy, MOKE magnetometry) the structural, vibrational, electronic, and magnetic properties of the three new graphene hybrid systems were characterized and confronted to first-principle calculations. Several striking features were unveiled. The interface between graphene and cobalt involves strong C-Co interactions which are responsible for a large interface magnetic anisotropy, capable of driving the magnetization out-of-the plane of the surface of an ultra-thin film in spite of the strong shape anisotropy in such films. The effect is maximized in the system obtained by intercalation between graphene and iridium, which comes naturally air-protected. Nanoclusters, on the contrary, seem to weakly interact with graphene. Small ones, comprising ca. 30 atoms each, remain super paramagnetic at 10 K, have no magnetic anisotropy, and it turns out difficult, even with 5 T fields to saturate their magnetization. Besides, the magnetic domains size seem to exceed the size of a single cluster, possibly pointing to magnetic interactions between clusters.

Le graphène, une monocouche de graphite, est composé d'atomes de carbone avec une structure en nid d'abeilles. Ses propriétés exceptionnelles ont attiré un intérêt mondial, dont le Prix Nobel de Physique en 2010. Le graphène épitaxié sur métal à rapidement été identifié comme un moyen de production de graphène de haute qualité de taille métrique, et est le sujet d'intenses activités de recherche en sciences de surface pour caractériser ses propriétés. En outre, ces études concernent aussi des systèmes plus complexes avec pour base le graphène, par exemple les réseaux ordonnés de nanoparticules à sa surface. Tout cela a mené à l'étude de la croissance, de la structure et des défauts du graphène épitaxié avec un grande variété de techniques expériementales, tel que la microscopie par effet tunnel, spectroscopie par photo-émission résolue en angle ou encore la microscopie électronique à basse énergie. Ce travail de recherche se concentre sur le graphène obtenu par croissance sur la surface (111) d'un monocristal d'iridium dans des conditions d'ultra vide et étudié avec plusieurs techniques de mesure par diffraction (diffraction de surface des rayons X, diffraction des rayons X en incidence rasante, réflectivité des rayons X et diffraction des électrons à haute énergie en réflexion). Ces expériences ont été faites au synchrotron européen ESRF à Grenoble, en France. La première partie de cette étude a été de déterminer la structure du graphène à l'échelle atomique. Le système montre une tendance à la commensurabilité, mais sa structure précise dépend fortement des conditions de préparation et de la température appliqué au système. En outre, en combinant des techniques de diffraction à haute résolution, une caractérisation précise de la structure, qui fait débat dans la littérature, est dévoilée. Le système étudié présente aussi une surperstructure, typique du graphène épitaxié, nommé moiré pour ses similarités avec l'effet optique du même nom. Celle-ci est utilisée comme gabarit pour faire croître des nanoparticules monodisperses à la surface en réseau auto-organisé. Durant cette étude, trois types de nanoparticules ont été examinés, des particules de platine de deux tailles différentes et des particules composées de platine et de cobalt. Ces systèmes hybrides présentent un fort degré d'organisation, partiellement hérité de la superstructure du moiré. Les nanoparticules forme une interaction forte avec leur support et elles subissent des contraintes de surface causées par leurs petites tailles. Par ailleurs, les nanoparticules de platine-cobalt, dont la croissance est en deux étapes, gardent une structure en couche et non une structure d'alliage métallique. / Graphene, a monolayer of graphite, is composed of carbon atoms arranged in a honeycomb lattice. Its exceptional properties have attracted a worldwide interest, including the Novel Prize in Physics in 2010. Epitaxial graphene on a metal was rapidly identified as an efficient method for large-area production of high quality graphene, and also was the matter of intense activities exploiting surface science approaches to address the various properties of graphene and of advanced systems based on graphene, for instance ordered lattice of metal nanoparticles on graphene. This resulted in the study of growth, structure and defects of epitaxial graphene on a wide variety of substrates with various techniques such as scanning tunneling microscopy, angle-resolved photoemission spectroscopy or low-energy electron microscopy. This work focuses on graphene grown on the (111) surface of iridium in ultra-high vacuum conditions and studied with several diffraction techniques (surface X-ray diffraction, grazing incidence X-ray diffraction, X-ray reflectivity, and reflection-high energy electron diffraction). These experiments were performed at the European Synchrotron Radiation Facility in Grenoble, France. The first step in our study was to determine the structure of graphene at the atomic scale. The system was found to have a tendency to commensurability, but that the precise structure depends on temperature and on preparation conditions. Moreover, with the combination of high resolution diffraction techniques, a precise characterization about the debated structure of graphene perpendicular to the surface was unveiled. The system, exhibits a superstructure, typical of epitaxial graphene, called a moiré, as an equivalent of the moiré effect in optics. This is used as a template to grown nanoparticles on top of the system to achieve the self-organisation of monodisperse nanoparticles. In this study, three type of nanoparticles were investigated, two different size of pure platinum ones and bimetallic ones, platinum and cobalt. These hybrid systems show very high degree of order, partly inherited by the superstructure lattice. The nanoparticles were found to strongly bond to their support, experience substantial surface strain related to their small size, and that bimetallic ones grown in a sequential manner retain a chemically layered structure.

Submitted by LAURA ROSA KUGLER DE AZEVEDO null (sofiamarilia@hotmail.com) on 2016-12-07T21:59:10Z No. of bitstreams: 1 Laura Azevedo_DissertFinal OK2.pdf: 648136 bytes, checksum: 9cbcf2e6ed9aa04bcac3c8fb18f0b750 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-12-12T12:49:30Z (GMT) No. of bitstreams: 1 azevedo_lrk_me_mar.pdf: 648136 bytes, checksum: 9cbcf2e6ed9aa04bcac3c8fb18f0b750 (MD5) / Made available in DSpace on 2016-12-12T12:49:30Z (GMT). No. of bitstreams: 1 azevedo_lrk_me_mar.pdf: 648136 bytes, checksum: 9cbcf2e6ed9aa04bcac3c8fb18f0b750 (MD5) Previous issue date: 2016-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A presente dissertação intitulada “Informação, ação e relações colaborativas: uma perspectiva filosófica da complexidade” tem por objetivo realizar um estudo de hipóteses do paradigma da complexidade envolvendo a comunicação entre seres humanos. O problema central que direciona a presente reflexão pode ser assim enunciado: Qual é o papel dos padrões informacionais na ação colaborativa dos seres humanos, concebidos como sistemas complexos? Esse problema será inicialmente analisado a partir da hipótese elaborada por Bateson, segundo a qual relações de dependência se estabelecem entre seres vivos, criando vínculos específicos e dinâmicos entre eles quando há reciprocidade em suas relações. Recorremos também às hipóteses formuladas por Weaver em 1948 sobre a natureza de problemas característicos do domínio da complexidade. O presente trabalho está organizado em três capítulos. No primeiro, investigamos aspectos da Teoria dos Sistemas Complexos que nos auxiliam a analisar o conceito de Informação, com ênfase na noção de Padrões Informacionais. No capítulo 2, investigamos a Virada Naturalista na filosofia e a importância da experiência para a filosofia, que passou a ganhar espaço com essa Virada, proporcionada pela revolução iniciada por Darwin na biologia. As noções de Padrões Informacionais e de Duplo-Vínculo são apresentadas no capítulo 2, que tem como ponto fundamental o estudo da relação comunicativa entre seres vivos. No capítulo 3, analisamos hipóteses de teorias que explicitam relações de amizade, presenciais e virtuais, entre pessoas, focalizando o estudo de relações colaborativas propiciadas pelo estabelecimento de padrões informacionais. / This dissertation, entitled “Information, action and collaborative relationships: a philosophical perspective of complexity” aims to conduct a study of hypotheses of the complexity paradigm involving communication between humans. The central problem that directs this reflection can be so stated: What is the role of informational patterns in the collaborative action of human beings, conceived as complex systems? This problem will be initially analyzed from the hypothesis elaborated by Bateson, according to which dependency relationships are established between living beings, creating specific and dynamic links between them when there is reciprocity in their relationships. We also investigate the assumptions made by Weaver in 1948 about the nature of problems dealing with complexity. This dissertation is organized into three chapters. In the first one, we investigated aspects of the Theory of Complex Systems that help us to analyze the concept of Information, emphasizing the notion of Informational Patterns. In chapter 2, we investigate the Naturalistic Turn in philosophy and the importance of experience to philosophy, which went on to gain space with this Turn, provided by the revolution initiated by Darwin in biology. The notions of Informational Patterns and Double-Bind are presented in the chapter 2 that presents the result of a study of the communicative relationship between living beings. In chapter 3, we analyze assumptions of theories that explain relations of friendship and virtual friendship between people, focusing on the study of collaborative relationships offered by the establishment of informational patterns.

Submitted by RENATA SILVA SOUZA null (renatynhass@hotmail.com) on 2017-10-26T17:42:23Z No. of bitstreams: 1 O PROBLEMA DA IDENTIDADE PESSOAL ANALISADO A PARTIR DE UMA PERSPECTIVA FILOSÓFICO-INTERDISCIPLINAR.pdf: 1305015 bytes, checksum: 2b8e339b7de9928b0dc3f21448f24d19 (MD5) / Rejected by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br), reason: Solicitado pela autora. on 2017-10-30T19:57:17Z (GMT) / Submitted by RENATA SILVA SOUZA null (renatynhass@hotmail.com) on 2017-11-02T19:45:54Z No. of bitstreams: 1 Renata Silva Souza - O PROBLEMA DA IDENTIDADE PESSOAL ANALISADO A PARTIR DE UMA PERSPECTIVA FILOSÓFICO-INTERDISCIPLINAR.pdf: 1305034 bytes, checksum: a1e57664ae24c6b9ba18d9cd9d042980 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-11-13T13:53:07Z (GMT) No. of bitstreams: 1 souza_rs_me_mar.pdf: 1305034 bytes, checksum: a1e57664ae24c6b9ba18d9cd9d042980 (MD5) / Made available in DSpace on 2017-11-13T13:53:07Z (GMT). No. of bitstreams: 1 souza_rs_me_mar.pdf: 1305034 bytes, checksum: a1e57664ae24c6b9ba18d9cd9d042980 (MD5) Previous issue date: 2017-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho é analisar o problema da identidade pessoal em uma perspectiva filosófico-interdisciplinar. O problema da identidade pessoal consiste na dificuldade de se estabelecer critérios que possibilitem (ou não) a identificação de características constantes de um indivíduo, como sendo o mesmo, apesar das inúmeras mudanças a que é suscetível ao longo da vida. Analisaremos o problema da identidade pessoal empregando recursos da filosofia da mente, da Teoria dos Sistemas Complexos (TSC) e da filosofia da informação, os quais sustentam o eixo interdisciplinar de nossa pesquisa. Na perspectiva da TSC, ênfase é dada ao modo pelo qual as partes de um sistema interagem entre si em diferentes escalas. Os conceitos de auto-organização, emergência e de complexidade, centrais à TSC, servirão como recursos de investigação do problema da identidade pessoal. Analisaremos, como um estudo de caso, possíveis implicações de modificações corporais concebidas pelos defensores do projeto transhumanista de aprimoramento humano radical. Com a análise dos pressupostos filosóficos subjacentes ao projeto transhumanista, pretendemos ilustrar aspectos da pesquisa filosófico-interdisciplinar na investigação do problema da identidade pessoal. / The aim of this work is to investigate the problem of personal identity from a philosophical-interdisciplinary perspective. The problem of personal identity concerns the difficulty of establishing criteria that allows (or not) the identification of constant characteristics of an individual that remains the same despite the many changes that occur throughout his/her life. We will address this problem by employing resources available from the areas of Philosophy of Mind, Complex Systems Theory (CST), and Philosophy of Information (this emphasizes the interdisciplinary nature of the proposed research). From the perspective of CST, emphasis is given to the ways in which different parts of a system interact with each other at various levels. The concepts of self-organization, emergence, and complexity, which are central to CST, can be of assistance in the investigation the problem of personal identity. We will analyze, as a case study, possible implications of bodily modifications conceived by proponents of the transhumanist project of radical human enhancement.Using an analysis of the philosophical criteria on which the transhumanist project is founded, we intend to illustrate ways in which aspects of philosophical and interdisciplinary research can be used to investigate the problem of personal identity.

Resilience is an essential and highly desired characteristic of a social-ecological system’s ability to adapt and adjust to various stresses and shocks that cause disruption. As social and ecological systems are intertwined and continually experiencing changes and disturbances, a major challenge appears revolving around the ways in which this resilience can be built and investigated. Social-ecological resilience can be defined as the amount of stress or disturbance that a particular system can tolerate, while still maintaining the same functions and identity. This paper uses social-ecological resilience concepts as a research framework, and examines three main themes that allow for the building of water management resilience to occur. These themes include learning to live with change, nurturing the ability to adapt/adjust to changes, and also on creating opportunities for self-organization. Two ethnic minority villages in Northern Thailand were chosen as research sites, in which the village water management practices were studied within a specific time period. Varying degrees of quantity and quality water issues within both villages have brought about stress and disturbances within their water management practices and increased the need to deal with these problems. Research was conducted at a community scale and resilience analysis pertains only to this specific level. Through the utilization of focus groups and interviews, qualitative data was collected and analyzed within a SE resilience context. This paper sets out to explore how social-ecological resilience has been built or not, and to what degree this has occurred within these two villages water management practices. The analysis indicates how complex and interconnected the social and ecological systems are and how the water management practices of these two communities play a role in this complex, dynamic process. Conclusions drawn are not limited to these two communities, but can be applied to the wider Northern Thailand region.

Les émulsions concentrées sont des empilements compacts désordonnés de gouttes d'huile dans de l'eau. A l'instar des suspensions colloïdales ou des mousses, leur comportement rhéologique est celui d'un liquide d'Herschel-Bulkley. A l'échelle microscopique, l'écoulement s'explique par des réarrangements plastiques et localisés des gouttes d'huile. L'objectif de cette thèse est de caractériser et comprendre ces dynamiques microscopiques.En adaptant la technique de Diffusing Wave Spectroscopy (DWS), nous avons mis au point une technique de détection résolue dans le temps et dans l'espace des réarrangements plastiques de gouttes. Nous avons élaboré des émulsions concentrés désordonnées et non Brownienne par émulsification membranaire. Un dispositif osmotique nous permet de contrôler in situ la pression de confinement de nos échantillons. Nous avons sondé les réarrangements de gouttes déclenchés en appliquant à nos échantillons des déformations uniaxiales d'amplitudes contrôlées. Nous avons observé la présence de réarrangements plastiques même aux plus petites amplitudes de déformations. / The concentrated emulsions are disordered compact packing of droplets of oil in water. As in the case of colloidal suspensions or foams, their rheological behavior is that of a Herschel-Bulkley liquid. On the microscopic scale, the flow is explained by plastic and localized rearrangements of the oil droplets. The objective of this thesis is to characterize and understand these microscopic dynamics. By adapting the Diffusing Wave Spectroscopy (DWS) technique, we have developed a time and space resolved detection technique for the plastic rearrangement of droplets . Concentrated, non-Brownian emulsions were developed by membrane emulsification. An osmotic device allows us to monitor in situ the confinement pressure of our samples. We have probed the rearrangements of droples triggered by applying to our samples uniaxial deformations of controlled amplitudes. We have observed the presence of plastic rearrangements even at the smallest amplitudes of deformations.

Recentemente, pesquisadores têm proposto o uso de Algoritmos Genéticos (AGs) para a determinação da estrutura tridimensional de proteínas. No entanto, este é um problema difícil para um AG tradicional, pois na maioria das vezes ocorre a convergência prematura das soluções para ótimos locais. Isto ocorre porque o uso de mecanismos de seleção no AG acarreta uma perda da diversidade das soluções. Assim, neste trabalho, são investigadas estratégias para controlar a diversidade da população do AG e evitar que a solução fique rapidamente presa em ótimos locais. São empregadas bases de dados de ângulos de torção para a cadeia principal, cadeia lateral e técnicas de controle de diversidade em AGs conhecidas como Hipermutação e Imigrantes Aleatórios. Além disso, um novo algoritmo baseado no AG com Imigrantes Aleatórios Auto-Organizáveis é proposto. Os resultados mostram que estas variações são efetivas no objetivo de não manter o conjunto de soluções preso a uma região apenas, além de melhorar o desempenho para o problema de determinação de estruturas terciárias de proteínas. / Recently, researchers have proposed the use of Genetic Algorithms (GAs) for the determination of the three-dimensional structure of proteins. However, this problem is considered a difficult problem for the standard GA, because most of the cases the convergence occurs early, into local minima instead of the global optimum. This occurs because the use of selection mechanisms in the GA leads to a loss of diversity of solutions. With this in mind, in this work, strategies to control the diversity of the population in the GA are investigated in order to avoid the solution subset to be early caught in local optima. Database sets of torsion angles for the main chain and the side chain are employed, and also modifications in the GAs, known as Hypermutation and Random Immigrants. Besides these approaches, a new algorithm based on the Self-Organizing Random Immigrants is proposed. Results show that these changes are effective in the goal of avoiding the results ensemble to be trapped in a region, and also help improve the performance for the protein structure prediction problem.

Orientador: Antonio Carlos de Moraes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica / Made available in DSpace on 2018-08-14T03:45:10Z (GMT). No. of bitstreams: 1 Leitao_RodrigoAparecidoAzevedo.pdf: 13998407 bytes, checksum: 93ed4e81434259f8b9cd13ff9e41a7e9 (MD5) Previous issue date: 2009 / Resumo: No desporto de alto rendimento, cada vez mais os detalhes fazem a diferença entre o primeiro e o segundo colocados. O jogo, e no nosso caso o jogo de futebol, é um fenômeno complexo, onde o desempenho de quem joga é transdimensional. A todo o tempo, jogadores e equipes são confrontados com situaçõesproblema, em circunstâncias com alto grau de imprevisibilidade que requerem respostas imediatas, técnicas, táticas, físicas e psicológicas ao mesmo tempo, não dissociadas e de forma integral. Os conflitos e soluções desencadeadas por tais situações geram um ambiente de jogo extremamente dinâmico de constantes ajustes em suas estruturas e com permanente mobilização da inteligência humana, individual e coletiva, que do ponto de vista da complexidade, se torna transdimensional. Caos, fractais, sistemas, jogo, imprevisibilidade; a real compreensão dos fenômenos que levam ao melhor rendimento e aos melhores resultados nas situações-problema do jogo deve transcender os óculos tradicionais que o observam como fenômeno. Dessa forma a proposição dessa pesquisa é: a) analisar o fenômeno da auto-organização no jogo de futebol; b) analisar a mobilização da atuação da inteligência humana em contexto específico de jogo com característica emergencial; c) justificar a necessidade de um modelo de treino para o futebol pautado no paradigma da complexidade. Para tanto, foi realizada pesquisa de caráter qualitativo: 1) com análise de ações técnico-táticas de jogadores de futebol, durante os jogos das quartas-de-final, das semifinais e da final da Copa do Mundo FIFA 2006; 2) através da análise de imagem, a 30 quadros por segundo, de situações específicas em contexto de urgência nesses mesmos jogos; e 3) através de procedimento de observação participante de uma equipe de futebol masculino sub-17, treinada sob o ponto de vista da complexidade. A partir das observações realizadas, podemos destacar dentre outras coisas, que: a) no jogo de futebol a inteligência humana se manifesta individual e coletivamente de acordo com cada circunstância; b) A mobilização da inteligência humana individual, observada em contexto de urgência, mostrou estar intimamente associada à intenção nas ações e à intencionalidade; c) a mobilização da inteligência coletiva de jogo mostrou estar associada a auto-organização das equipes, sendo essa (a autoorganização) a manifestação da inteligência em constante interação com os atratores e outros elementos do sistema "jogo"; d) é o sistema "jogo" que comporta a interação dos sistemas organizacionais das equipes que jogam. A organização de cada um desses sistemas pode ser influenciada e influenciar a organização adversária através, ou de uma interação melhor com o sistema "jogo", ou de ruídos que são gerados por cada uma das equipes visando desequilibrar o adversário (futebol de influência); e) como a organização funciona como uma identidade do sistema, para mantê-la, jogadores e equipes precisam de referências que permitam melhor leitura de jogo e autonomia para as ações. O esquema tático, por exemplo, pode se configurar como uma dessas referências (e também como um atrator do sistema); f) a transdimensionalidade das situações-problema do jogo, sob as lentes da complexidade, justifica a necessidade de um modelo de treino subordinado ao jogo. / Abstract: In high-level sports, small things make difference between the first and second positions. The game, and in this is case the soccer game, is a complex phenomenon where the player's performance is transdimensional. At every time players and teams meet problem-situations, in unpredictable circumstances that need fast technical, tactical, physical and psychological responses, at the same time not separated and comprehensive. The conflicts and the solutions in these situations create a dynamic game environment, with many adjusts in its structures and permanent individual and collective human intelligence mobilization, from the point of view of complexity, it becomes trans-dimensional. Chaos, fractals, systems, game, unpredictability; the real phenomena understanding needs to transcend the traditional view that sees it as phenomenon. Then, the purpose of this research is: a) to analyze the self-organization in soccer game; b) to analyze the human intelligence mobilization in specific game circumstance, with emergency characteristics; c) to justify the need of a training model for soccer based on the complexity paradigm. For this, a qualitative research was carried out: 1) with technical-tactical analysis of soccer players' actions, on round of eight, semi-finals and final of the FIFA World Cup 2006; 2) through image analysis, at 30 frames per second, in emergency specific situations, in the same games, and 3) through the participant observation procedure of a soccer team U-17 male, trained from the point of view of complexity. From observations, we can point out that: a) in soccer game, the human intelligence appears individually and collectively, under the circumstances; b) the individual human intelligence mobilization, observed in urgency situation, is closely associated with the actions intention and intentionality; c) the game human intelligence mobilization is associated with team's self-organization, and this (the selforganization) is the manifestation of intelligence in constant interaction with attractors and other elements of game systems; d) it is the "game" system that contains interaction between the organizational systems of the teams that play. The team organizational systems can be influenced and influence the opponent organization through, either best game system interactions, or noises that are created to unbalance the opponent (influence soccer); e) if the organization is the system's identity, to keep it, players and teams need references that let the best game perception and autonomy to actions. The tactical scheme, for example, can configure with these references (and with system's attractor too); f) trans-dimensionality of game problem-situations, under the complexity's lens, justified the need of a training model subordinated to the game. / Universidade Estadual de Campi / Ciencias do Desporto / Doutor em Educação Física

Orientadores: Harry Westfahl Junior, Amir Ordacgi Caldeira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-10T23:02:41Z (GMT). No. of bitstreams: 1 Fernandes_RafaelMonteiro_D.pdf: 6829160 bytes, checksum: 4dfae2ffd4b06c5c3c1f89f399700913 (MD5) Previous issue date: 2008 / Resumo: Um dos objetivos centrais das Ciências Naturais é relacionar as estruturas dos mais diversos sistemas com as funções particulares que os caracterizam. Por exemplo, no que se refere a materiais, sejam eles sintéticos ou biológicos, a ciência está constantemente buscando a predição de diferentes propriedades macroscópicas a partir do conhecimento das suas estruturas mi- croscópicas. Nesta tese, investigamos as propriedades magnéticas e de transporte de sistemas que apresentam interações competitivas em diferentes escalas de comprimento. Como resultado desta competição, surge um estado termodinâmico caracterizado por um parâmetro de ordem modulado, dando origem a uma série de con.gurações espacialmente inomogêneas. A termo- dinâmica destes estados modulados pode ser descrita pelo chamado modelo de Brazovskii, que prevê uma transição de primeira ordem, induzida pelas .utuações do parâmetro de ordem, entre a fase homogênea e a fase modulada. Há uma vasta gama de sistemas encontrados na Natureza que parecem se encaixar nesta descrição de Brazovskii, compreendendo estruturas tão díspares quanto cristais líquidos e condensados de píons em estrelas de nêutrons. No presente trabalho, investigamos dois sistemas físicos particulares. Motivados pela rica variedade de domínios obser- vados experimentalmente em filmes finos magnéticos, estudamos as propriedades magnéticas de blocos ferromagnéticos dipolares com dimensões finitas e condições de contorno não-periódicas. Desenvolvendo uma modelagem baseada na solução da Hamiltoniana de Brazovskii, pudemos explicar, de maneira inédita e consistente, a estrutura de domínios magnéticos dos filmes finos de MnAs:GaAs, um promissor candidato a aplicações no campo da spintrônica. Além disso, estabelecemos uma relação clara entre o fenômeno de reorientação magnética e a mudança na forma das curvas de histerese observada nesses filmes. O segundo tipo de sistemas que in- vestigamos foram os isolantes de Mott, cujas propriedades de transporte foram determinadas a partir do modelo de redes de resistores correlacionados. Considerando que a transição de Mott térmica pertence à classe de universalidade de Ising, mostramos que a condutividade macroscópica depende não apenas da magnetização, mas também da densidade de energia, dando origem a um comportamento de crossover. Através destes resultados, lançamos luz sobre a aparente e misteriosa incoerência entre as previsões teóricas e as medidas experimentais recentes envolvendo isolantes de Mott não-dopados. Prosseguindo para as fases inomogêneas dos isolantes de Mott dopados, estudamos a condutividade macroscópica das mesofases eletrônicas com ordenamento de carga esmético e nemático, as quais são encontradas nos niquelatos e nos cupratos, respectivamente. Inspirados nos conceitos da Física dos cristais líquidos, expressamos de forma bastante intuitiva a relação entre as propriedades de transporte e a termodinâmica das mesofases eletrônicas anisotrópicas, descrita pelo modelo de Brazovskii / Abstract: Natural Sciences is to relate the structures of systems to example, in what concerns materials, either synthetic or for the prediction of different macroscopic properties from the knowledge of their microscopic structure. In this thesis, we investigate the magnetic and transport properties of systems with competing interactions in distinct length scales. As a result of such a competition, there is a thermodynamic state characterized by a modulated order parameter, originating a set of spatially inhomogeneous con½gurations. The thermodynamics of these modulated states can be described by the so-called Brazovskii model, which predicts a fluctuation induced first order transition from the homogeneous phase to the modulated phase. There is a large diversity of systems for which the Brazovskii description seems suitable, including utterly disparate structures such as liquid crystals and pion condensates in neutron stars. In the present work, we investigate two particular physical systems. Motivated by the rich variety of domains experimentally observed in magnetic thin films, we study the magnetic properties of ferromagnetic dipolar slabs with finite dimensions and non-periodic boundary conditions. After developing a model based on the solution of the Brazovskii Hamiltonian, we were able to explain, in a consistent and novel way, the magnetic domain structures of MnAs:GaAs thin films, which are promising candidates for spintronics devices. Moreover, we established a clear connection between the film's magnetic reorientation and the experimentally observed change in the hysterisis loops shape. The second class of systems we investigated were the Mott insulators, whose transport properties were determined from the correlated resistor network model. After considering that the finite temperature Mott transition belongs to the Ising universality class, we showed that the macroscopic conductivity depends not only on the magnetization, but also on the energy density, giving rise to crossover behaviour. Using these results, we shed light upon the apparent and mysterious inconsistency between the theoretical predictions and the experimental measurements regarding undoped Mott insulators. Proceeding to the inhomogeneous phases of doped Mott insulators, we studied the macroscopic conductivity of electronic mesophases with smectic and nematic charge ordering, which are found in the nickelates an in the cuprates, respectively. Inspired by the concepts from the Physics of liquid crystals, we expressed in an intuitive way the connection between the transport properties and the thermodynamics of anisotropic electronic mesophases described by the Brazovskii model / Doutorado / Física da Matéria Condensada / Doutor em Ciências