Orientadores: Sandra Augusta Santos, Jose Mario Martinez / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-08T17:04:51Z (GMT). No. of bitstreams: 1 Xavier_LarissaOliveira_M.pdf: 1818711 bytes, checksum: e0305d93bde788c50b64809da1b8bf9e (MD5) Previous issue date: 2007 / Resumo: Este trabalho encaminha a investigação de questões relacionadas ao desempenho de algoritmos de região de confiança para problemas de otimização irrestrita de grande porte. O algoritmo clássico de Moré e Sorensen, baseado em fatorações de Cholesky, é comparado com a abordagem de Rojas, Santos e Sorensen (algoritmo RSS). Do ponto de vista teórico são estudados os resultados de convergência dos dois algoritmos. Em termos práticos, são resolvidos problemas com a estrutura típica de empacotamento de cilindros. Também são pesquisados o desempenho efetivo do algoritmo RSS na solução aproximada dos subproblemas, e a repercussão da precisão com que os subproblemas são resolvidos no esforço global do algoritmo. / Abstract: This work investigates issues related to the performance of trust-region algorithms for large-scale unconstrained minimization. The classic algorithm of Moré and Sorensen, based on Cholesky?s factorizations, is compared with the approach of Rojas, Santos and Sorensen (algorithm RSS). From the theoretic standpoint, the convergence results of both algorithms are compiled. In practical terms, problems with the typical structure of packying of cylinders are solved. The effective performance of the algorithm RSS in the approximate solution of the subproblems is analyzed as well, together with the influence of the inner precision of the subproblems to the global effort of the algorithm / Mestrado / Otimização / Mestre em Matemática Aplicada

A presente tese, de natureza analítica, defende, a partir da análise dos elementos subjacentes à ideia de direito como sistema por trás da discussão sobre a fragmentação do direito internacional, que a expansão do direito internacional no século XX foi acompanhada de uma mudança do conceito de legitimidade, que não se restringe mais apenas ao reconhecimento do Estado como produtor das normas internacionais, mas requer parâmetros substantivos que orientam a solução dos conflitos entre normas que são produzidas em diferentes esferas normativas. No entanto, ao contrário do que ocorre no ordenamento interno, cujo sistema jurídico estabelece uma hierarquia de normas neutralizada pela ideologia do regime existente, nas relações internacionais, a horizontalidade das normas do direito internacional reflete a inexistência de uma cadeia tal de valores; e nem mesmo a proliferação de normas secundárias na segunda metade do século XX logrou alterar os fundamentos da jurisdição internacional, a qual ainda encontra diversas restrições associadas às características do direito internacional de coexistência. Estes problemas serão evidenciados pela análise do que ocorre no âmbito da OMC e, dentre as diversas disputas que envolvem normas produzidas em diferentes esferas normativas, do caso Brazil Measures Affecting Imports of Retreaded Tyres (União Européia v. Brasil) [doravante Brazil Retreaded Tyres]. / From analysis of the factors underlying the idea of law as a system behind the discussion of the \"fragmentation\" of international law, this thesis, analytical in nature, argues, that the expansion of international law in the twentieth century was accompanied by a change in the concept of legitimacy, which is no longer restricted only to the State as a producer of international standards, but requires substantive parameters to guide the resolution of conflicts between rules from different normative spheres. However, unlike domestic domains, where the legal system establishes a hierarchy of norms neutralized by the ideology of the existing regime, in international relations, the horizontality of the norms of international law reflects the absence of such a chain of values, nor even the proliferation of secondary standards in the second half of the twentieth century managed to change the fundamentals of international jurisdiction, which still faces several constraints associated with the characteristics of the international law of coexistence. These problems will be highlighted by the analysis of what occurs in the WTO and, among the several disputes involving standards from different normative spheres, the case of Brazil Measures Affecting Imports of retreaded Tyres (European Union v. Brazil) [hereinafter Brazil - retreaded Tyres].

Esta tese tem por objetivo explorar os mecanismos e dinâmicas que podem afetar as trajetórias educacionais dos jovens, provocando mudanças ou fortalecendo a sua direção inicial. Para caracterizar o tipo de trajetória, olhamos para os seguintes elementos: distorção idade-série, reprovações, expulsões e evasão escolar. Exploramos de que forma as esferas de sociabilidade em que os jovens estão inseridos - a família, a escola, a vizinhança, o trabalho, os programas sociais, a igreja e o lazer se articulam e afetam as suas trajetórias escolares. Além disso, investigamos em que medida eventos que ocorrem ao longo da vida do jovem podem afetar a sua conduta, a sua relação com os elos estabelecidos nos diferentes espaços de sociabilidade e, consequentemente, os seus percursos educacionais. As análises feitas neste trabalho são de cunho qualitativo. Utilizamos os seguintes instrumentos: entrevistas em profundidade, guiadas por um roteiro prévio, conversas livres, observação participativa e observação passiva da interação. Apesar de termos nos limitado a uma escola, encontramos entre os entrevistados heterogeneidade em termos de atributos individuais e dimensões socioeconômicas e culturais, fatores que influenciam as trajetórias escolares. No entanto, identificamos jovens com atributos e condições socioeconômicas similares, mas trajetórias distintas. Nestes casos, as relações estabelecidas com os elos das esferas de sociabilidade e as formas como lidaram com as situações de crise explicam as diferenças encontradas. / This thesis aims to explore the mechanisms and dynamics that may affect, cause changes or strengthen the initial direction of the educacional trajectories of youngsters. In order to characterize the type of trajectory, we looked at the following factors: age-grade distortion, grade retention, expulsion and drop-out. We explored how the spheres of sociability of the youngsters - family, school, neighbourhood, work, social programs, church and leisure - are associated and affect their school trajectories. In addition, we investigated the extent to which events that occur throughout their life can affect their behaviour, their relationship with ties established in different spheres of sociability and, consequently, their educational trajectories. The analysis made in this study are qualitative. The following instruments were used: in-depth interviews, free conversations, participant observation and passive interaction observation. Although we limited ourselves to one school, we found heterogeneity among respondents in terms of individual attributes and socioeconomic and cultural dimensions, factors that influence school trajectories. However, we identified young people with similar socioeconomic characteristics and conditions but distinct paths. In these cases, the differences found can be explained by the relationship established with ties in spheres of sociability and the ways in which crisis situations were dealt with

Orientadores: Carlile Campos Lavor, Jose Mario Martinez / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-11T21:12:00Z (GMT). No. of bitstreams: 1 Goncalves_MarcosRobertodaSilva_M.pdf: 1220561 bytes, checksum: e3b9dadf0b151f53d8a3e0e572b4c7ab (MD5) Previous issue date: 2008 / Resumo: Neste trabalho, abordamos o problema da determinação de pontos de intersecção de n esferas no Rn. Este problema, além de ser importante matematicamente, é um problema com muitas aplicações, que vão desde a localização de pontos no globo, pelo sistema GPS, até a posicionamento de átomos em estruturas moleculares. O problema de encontrar a intersecção de n esferas no Rn é, em geral, formulado como um conjunto de n equações não-lineares, onde se deseja determinar a sua solução através de um método eficiente e confiável. Mostramos que, com exceção de alguns casos, o problema é geralmente resolvido de forma eficaz, empregando técnicas de álgebra linear. Reformulamos o problema de forma a convertê-lo em um problema linear e apresentamos dois métodos baseados na decomposição de matrizes. Testamos os métodos para casos particulares de baixa dimensão, analisando o custo computacional e possíveis dificuldades que podem surgir devido a erros de medição. / Abstract: We consider the problem of determining the points of intersection of n spheres in R n. This problem has many applications, such as the location of points on the globe by the GPS system and problems related to molecular geometry optimization. The problem of finding the intersection of n spheres in R n is generally expressed as a set of nonlinear equations, where we want to establish an efficient and reliable method to find their solution. We show that, in general, the problem can be solved effectively employing techniques of linear algebra. We reformulate the problem in order to transform it into a linear problem and present two methods based on the decomposition of matrices. We also test the methods in small instances and analyze the computational cost and possible difficulties that may arise due to errors of measurement. / Mestrado / Mestre em Matemática

Le but de cette thèse est d’étendre les résultats de l'article [B-M] sur les relations entre variétés moment-angle et variétés complexes. On s'intéressera ici aux variétés moment-angle issues d'une décomposition simpliciale (et non simplement polytopale) de la sphère. On cherchera ensuite à utiliser la relation entre ces deux types d’objets pour comprendre la topologie de certaines variétés complexes.[B-M] F.Bosio, L.Meersseman, Real quadrics in Cn, complex manifolds and polytopes, Acta Mathematica, 197 (2006), n° 1, 53 -- 127. / The aim of this thesis is to extend the results of the article [B-M] on the relations between moment-angle complexes and complex manifolds. We will focus here on moment-angle complexes defined by a simplicial (not only polytopal) decomposition of the sphere. We will also seek to use the relationship between these two kinds of objects to be understand the topology of several complex manifolds. [B-M] F.Bosio, L.Meersseman, Real quadrics in Cn, complex manifolds and polytopes, Acta Mathematica, 197 (2006), n° 1, 53 -- 127.

Isotropic conductive adhesives (ICAs) have a growing range of applications in electronics packaging and have recently emerged as an important material in photo-voltaic module interconnections, particularly for thin-film and other non-silicon technologies where soldering processes are often unsuitable due to the nature of the metallisation or the limited maximum temperature the assembly can be exposed to. ICAs typically comprise of a high volume fraction of solid metallic flakes, usually silver, in an adhesive matrix because of its highly conductive oxide however, this thesis will focus on adhesives containing a large volume fraction of silver coated/metalised mono-sized polymer spheres (Ag-MPS). Incorporating silver coated mono-sized polymer spheres is anticipated to deliver specific advantages such as a significant reduction in the required silver content, improvement of the overall mechanical properties and flexibility to tune the properties of the filler according to the application compared with conventional flake filled adhesives. In this research advancements in the understanding of Ag-MPS filled ICAs, both through theory and experiments, have been made. Analytical models to predict an individual Ag-MPS resistance and Ag-MPS filled ICA resistance have been developed. The experiments based on the flat punch nanoindentation technique have been conducted to determine individual Ag-MPS resistances. The theoretical and experimental studies establish Ag-MPS diameter, coating resistivity, coating thickness, contact radius, and contact geometry as the main contributors towards the resistance of an Ag-MPS filled ICAs. These studies showed that Ag-MPS resistance decreases with increasing coating thickness and contact radius but increases with increasing coating resistivity. The experiments have also been conducted to investigate the effect of Ag-MPS volume fraction, diameter, coating thickness, curing conditions and shrinkage (affecting contact radius) on ICA conductivity and comparisons are made with flake filled and commercial ICAs. The results showed that ICA conductivity increases with increasing volume fraction and coating thickness but decreases with diameter. More importantly the results showed that conductivities similar to those of flake filled ICAs, including those commercially available, can be obtained using 70% less silver. The results show that, Ag content can be reduced further to just 7% with use of larger 30μm Ag-MPS but with a lower resulting conductivity. Thus for applications where very high conductivity is not required larger Ag-MPS may offer even greater potential cost benefits, which is something flake filled ICAs cannot offer. This is a significant achievement which can allow tuning of ICA formulations according to the demands of the application, which is not possible with the use of silver flakes as there is only a limited range of silver flake volume fractions that will yield useful levels of conductivity.

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Rounded objects, such as spheroids, are frequently found throughout the Fremont region. Because little information is known about these spheroids, this comprehensive analysis of spheroids contributes to definitions of and variation among Fremont spherical objects. I analyzed over 400 Fremont spheroids recording the size, weight, stone type, and other quantifiable aspects for each spheroid. The provenience of spheroids highlights some of the patterns and variability within the Fremont world. I also compare ethnographic accounts of purposes of spheroids in hopes to develop a better understanding of the function of these objects.

A simple and facile way to the fabrication of nano to micro scale organic-inorganic hybrid particles was demonstrated. A well known “template-assisted approach” was chosen for the preparation of these hybrid particles, in which the inorganic material of interest is templated against the template particles. A series of colloidal template particles including, polystyrene, poly (vinylcaprolactam) and poly (N-isopropylacrylamide) was used for the deposition of a variety of metal oxides/hydroxide nanoparticles. A classical surfactant free co-polymerization process was employed for the synthesis of these template particles. To facilitate the deposition of inorganic nanoparticles in subsequent steps, these colloidal particles were functionalized with the suitable functional groups. For this purpose, polystyrene particles were synthesized in the presence of acetoacetoxyethylmethacrylate (AAEM) co-monomer. Similarly, poly (vinylcaprolactam) and poly (N-isopropylacrylamide) particles were functionalized by adding AAEM and acrylic acid co-monomers, respectively, during their synthesis. It is thought that an effective interaction between these functionalities of employed template and metal oxide/hydroxide precursors is the driving force for the fabrication of organic-inorganic hybrid particles. A number of metal oxide/hydroxide nanoparticles including ZnO, TiO2, Ta2O5 and In(OH)3 were deposited on the surface of polystyrene colloidal particles. A systematic variation in the employed reaction conditions allowed a modulation in size, shape, morphology, shell thickness and inorganic contents of resulting hybrid particles. Similar effect of the employed Indium isopropoxide concentration on the morphology of PS-In(OH)3 hybrid particles was observed. In the case of PS-TiO2 and PS-Ta2O5 only core-shell morphology was observed. However, suitable surface chemistry and careful selection of reaction parameters allowed the deposition of as much thick as 130 nm TiO2/Ta2O5 shell on the polystyrene core. In addition, a controlled manipulation of the shell thickness with the employed concentration of inorganic salt was observed. Polystyrene colloidal particles coated with a high refractive index material such as TiO2, were employed as building blocks for the fabrication of self assembled colloidal crystals. The variation in particle size and TiO2 content of employed building blocks allowed the manipulation in stop band position and band width of resulting photonic structures. Furthermore, PS-ZnO hybrid particles with raspberry-like morphology were exploited as carrier for ZnO nanoparticles into a host polymer matrix to achieve a nanocomposite material. In addition, fabrication of a series of closed, intact and mechanically robust hollow spheres, composed of pure and mixed metal oxides was demonstrated. The removal of polystyrene core from PS-TiO2 and PS-Ta2O5 hybrid particles by chemical or thermal treatment resulted into the hollow TiO2 and Ta2O5 spheres, respectively. Templating of PVCL colloidal particles against ZnO nanoparticles was shown and variation in physical properties of the resulting hybrid microgels as a function of the loaded amount of ZnO nanoparticles was demonstrated. PVCL-ZnO hybrid microgels showed the temperature sensitivity of the template particles and the UV-absorbing property of the loaded ZnO nanoparticles. It was demonstrated that these hybrid materials can effectively be used in the preparation of a transparent UV-shielding material. In addition, the deposition of preformed and functionalized quantum dots (CdTe) on the surface of PNIPAm microgel particles was explored and a manipulation in the fluorescent properties of loaded quantum dots as a result of temperature induced swelling and deswelling of microgel template was investigated. It was found that the fluorescence of deposited quantum dots can be switched to “ON” or “OFF” by changing the temperature of the surrounding media. These hybrid particles are envisioned to be used in the fabrication of temperature nanosensors.