Orientadores: Patricio Anibal Letellier Sotomayor e Kyoko Furuya / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-11T10:44:32Z (GMT). No. of bitstreams: 1 Silva_MarceloZimbres_M.pdf: 810192 bytes, checksum: 16b4f94ccf4183c0371eac2b660a72f3 (MD5) Previous issue date: 2008 / Resumo: Para estudar de forma completa a precessão de um giroscópio em órbita, revisamos a dedução das equações de Papapetrou, em particular, para mostrar que em uma aproximação de partícula teste essas equações implicam o transporte de Fermi-Walker do spin. Para estudar as correções devidas a oblaticidade de um corpo central na precessão do spin, fizemos uma revisão da teoria dos multipolos relativísticos focados nas definições de Geroch-Hansen e de Thorne. Usamos todos esses conceitos para estimar as correções multipolares na precessão de Lense-Thirring, em especial, encontramos uma fórmula exata para a precessão em termos de dois escalares, as partes real e imaginária do potencial de Ernst. Em uma aproximação linear para o campo gravitacional, escrevemos nossa fórmula em termos dos multipolos de Thorne. Para estimar essas correções usamos alguns modelos conhecidos para a métrica do planeta Terra e comparamos nossos resultados com outros trabalhos / Abstract: To study the precession of an orbiting gyroscope we review the theory of the Papapetrou equations and show that they imply the Fermi-Walker transport law. We review also the theory of relativistic multipole moments, specifically the definitions of Geroch-Hansen and Thorne, to describe non-spherical bodies in general relativity. For stationary axially symmetric spacetimes we find a simple expression for the Lense-Thirring precession in terms of the Ernst potential. This expression is used to compute, in the weak field approximation, the major non-spherical contributions to the precession of a gyroscope orbiting the Earth. We use some known models for the earth metric to estimate the contributions and compare our results with some previously known ones / Mestrado / Física / Mestre em Física

L’objet de cette thèse concerne l’étude asymptotique des processus de branchement sur-critiques en environnement aléatoire, qui sont une généralisation du processus de Galton-Watson, avec une loi de reproduction choisie aléatoirement et de manière i.i.d. suivant les générations. Dans le cas de non extinction, nous démontrons une succession de résultats asymptotiques plus fins que ceux établis dans des travaux antérieurs. Le chapitre 1 est consacré à l’étude de l’écart relatif entre le processus (Zn) normalisé et la loi normale. Nous établissons une borne de type Berry-Esseen ainsi qu’un développement pour des déviations de type Cramér, généralisant ainsi le théorème central limite et le principe des déviations modérées établis précédemment dans la littérature. Le second chapitre concerne l'asymptotique de la distribution du processus (Zn) ainsi que le moment harmonique critique de la variable limite W de la population normalisée. Nous établissons un équivalent de l'asymptotique de la distribution du processus Zn et donnons une caractérisation des constantes via une équation fonctionnelle similaire au cas du processus de Galton-Watson. Dans le cas des processus de branchement en environnement aléatoire, les résultats améliorent l'équivalent asymptotique de la distribution de Zn établi dans des travaux antérieurs sous normalisation logarithmique, sous la condition que chaque individu donne naissance à au moins un individu. Nous déterminons aussi la valeur critique pour l'existence du moment harmonique de W sous des conditions simples d'existence de moments, qui sont bien plus faibles que les hypothèses imposées dans la littérature, et généralisons le résultat à Z_0=k individus initiaux. Le troisième chapitre est consacré à l'étude de l'asymptotique des moments harmoniques d'ordre r>0 de Zn. Nous établissons un équivalent et donnons une expression des constantes. Le résultat met en évidence un phénomène de transition de phase, relié aux transitions de phase des grandes déviations inférieures du processus (Zn). En application de ce résultat, nous établissons un résultat de grandes déviations inférieures pour le processus (Zn) sous des hypothèses plus faibles que celles imposées dans des travaux précédents. Nous améliorons également la vitesse de convergence dans un théorème central limite vérifié par W_n-W, et déterminons l'asymptotique de la probabilité de grandes déviations pour le ratio Zn+1/Z_n. / The purpose of this Ph.D. thesis is the study of branching processes in a random environment, say (Z_n), which are a generalization of the Galton-Watson process, with the reproduction law chosen randomly in each generation in an i.i.d. manner. We consider the case of a supercritical process, assuming the condition that each individual gives birth to at least one child. The first part of this work is devoted to the study of the relative and absolute distance between the normalized process log Z_n and the normal law. We show a Berry-Esseen bound and establish a Cramér type large deviation expansion, which generalize the central limit theorem and the moderate deviation principle established for log Z_n in previous studies.In the second chapter we study the asymptotic of the distribution of Z_n, and the critical value for the existence of harmonic moments of the limit variable W of the normalized population size. We give an equivalent of the asymptotic distribution of Z_n and characterize the constants by a functional relation which is similar to that obtained for a Galton-Watson process. For a branching process in a random environment, our result generalizes the equivalent of the asymptotic distribution of Z_n established in a previous work in a log-scale, under the condition that each individual gives birth to at least one child. We also characterize the critical value for the existence of harmonic moments of the limit variable W under weaker conditions that in previous studies and generalize this result for processes starting with Z_0=k initial individuals. The third chapter is devoted to the study of the asymptotic of the harmonic moments of order r>0 of Z_n. We show the exact decay rate and give an expression of the limiting constants. The result reveals a phase transition phenomenon which is linked to the phase transitions in the lower large deviations established in earlier studies. As an application, we improve a lower large deviation result for the process (Z_n) under weaker hypothesis than those stated in the literature. Moreover, we also improve the rate of convergence in a central limit theorem for W-W_n and give the asymptotic of the large deviation for the ratio Zn+1/Z_n.

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Ce manuscrit présente les travaux de recherche qui concernent l'analyse et la synthèse de structures rayonnantes multidimensionnelles en utilisant une approche qui combine méthode des moments et la transformée de Fourier spatiale. La distribution source (courant électrique) et le diagramme de rayonnement sont liées par la transformée de Fourier spatiale - la théorie de la Relation de Fourier (FR). La distribution des courants est déterminée en utilisant une méthode d'analyse en électromagnétisme (EM), à savoir la Méthode des Moments (MoM). Des travaux antérieurs utilisant la théorie FR ont été réalisés par d'autres auteurs sur des réseaux linéaires - uniformément espacés ou non uniformes. Les sources radiantes élémentaires des dipoles électriques filaires. Les travaux actuels se développent en utilisant la théorie FR à deux et trois dimensions sur des structures réelles. En utilisant la méthode MoM nous pouvons prendre en compte le rayon du fil, sur n'importe quel point d'excitation (générateur de tension ou onde incidente) et le couplage mutuel entre les éléments, créant ainsi un modèle électromagnétique réaliste pour la structure d'antenne / This manuscript presents the research work in the analysis and synthesis of multidimensional radiating structures using an approach that combines Method of Moments and Spatial Fourier Transform. The source distribution (electric current) and radiation pattern are related by the spatial Fourier Transform - Fourier Relation theory (FR). Current distribution is determined using Computational Electromagnetics (CEM), namely Method of Moments (MoM). Previous work using FR theory was done by other authors on linear arrays – uniformly or nonuniformly spaced elemental radiators laid on a straight line. Present work expands FR theory to two and three dimensions on real-world structures. By using MoM we can take into account wire radius, excitation on any point (voltage generator or incident wave) and mutual coupling between elements, thus creating a realistic electromagnetic model for the antenna structure

This analysis studies the phenomenon of the New Keynesian Phillips Curve - its inception from the RBC theory and DSGE modelling via incorporation of nominal rigidities, and its various specifications and empirical issues. The estimates on Czech macroeconomic data using the Generalised Method of Moments show that the hybrid New Keynesian Phillips Curve with the labour income share or the real unit labour cost as driving variables can be considered as an appropriate model describing inflation in the Czech Republic. Compared to other analyses, we show that the inflation process in the Czech Republic exhibits higher backwardness vis-a-vis other researchers' estimates based on US data.

This thesis presents a comparative and theoretical meta-study of a beneficial phenomenon experienced in some therapeutic and pastoral relationships, which I describe as a ‘moment of deep encounter’. The phenomenon is distinguished and defined, the research aims and approach described, and the research’s underpinning theoretical frame explained. The relevant data, being various deep-moment accounts and insights already existing within some pertinent areas of the literature, were analysed through a qualitative, three-stage meta-study. The development of some thematic coding, to identify and thematically analyse relevant data, is explained, and the collated thematic findings set out. These were then compared and critiqued through a meta-analysis, the findings from which were themselves meta-synthesised into an explanatory framework in order to map and relate various deep-moment experiences, perspectives, and understandings. The study identifies the patterns of occurrence of moments of deep encounter, their constituent aspects and the factors involved in their facilitation, some pertinent boundary issues and relevant theoretical perspectives, and the nature, relationship and cogency of various competing interpretations. Methodological, theoretical, and practical contributions are set out; the study is evaluated; and future research suggested. As far as I am aware, this research provides a larger overview and deeper analysis than any previously undertaken regarding moments of deep encounter. Moreover, such moments provide a lens into wider issues of theory and practice. The research invites a greater awareness of the beneficial effects of moments of deep encounter, greater attentiveness to their constituent aspects and characteristics, and greater openness to their interpretive possibilities, so as to enhance therapeutic and pastoral practice.

Background: This thesis reflects upon a heuristic study of a Storytelling Programme which took place in a KS3 Pupil Referral Unit. Previous experiences in the field, as a community storyteller, revealed the power of stories to calm and engage young people. In my community work I had seen that storytelling particularly engaged those considered ‘hard to reach.’ This research was designed to explore the storytelling process further with the aim of understanding more about the impact of the process and to understand the key components as identified by the young people themselves. Methodology: A heuristic research methodology was adopted within this study. The Storytelling Programme was delivered to twelve young people at a Pupil Referral Unit in the North West of England. Five of these participants were interviewed along with their teacher, and their reflections were integrated with my own to create a crystallized understanding of the storytelling process, whilst also remaining true to the unique experiences of each participant. Findings: Heuristic analysis of the Storytelling Programme revealed that young participants developed new personal narratives that reflected new ways of being and thinking. Change was demonstrated by the young people expressing a more positive sense of self. A striking finding, echoed by all participants, was the significance of the relationship in facilitating the therapeutic change process. Discussion: Whilst some of the changes could be linked to particular stories, the participants could not articulate whether their increased sense of well-being came from the stories or more generally from the programme or my ‘way of being’ (Rogers, 1980). It appears that stories and the therapeutic relationship intertwine within the storytelling process to create opportunities for therapeutic change. The findings of this study suggest that story is a particularly useful indirect medium to engage ‘hard to reach’ young people who have disorganised attachment styles. Storytelling offers the opportunity to place the intersubjective relationship as central, fostering an implicitly nurturing and co-regulating dyad that can offer reparation as well as the opportunities for catharsis and the development of emotional literacy through the processing of the story material. Conclusion: It appears that storytelling intertwines the interpersonal relationship with the stories to create a process which is both interpersonal and intrapersonal. The storytelling process appears to facilitate dyadic co-regulation, which may be an essential first step in the therapeutic change process. Once in a state of calm the young people could connect to the story stimuli and develop new ways of being and thinking. Whilst stories appear to promote changes at both the relational and semantic level, the findings from this study suggest that the implicit relational changes had primacy in facilitating significant therapeutic change.

Orientadores: Fanny Béron, Kleber Roberto Pirota / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-30T20:53:23Z (GMT). No. of bitstreams: 1 Velo_MuriloFerreira_M.pdf: 6384347 bytes, checksum: 64859a7498ff2d02184a4fff9787d436 (MD5) Previous issue date: 2016 / Resumo: Interações dipolares são amplamente estudadas em magnetismo, devido ao fato de que elas têm um papel fundamental na maioria dos sistemas magnéticos. Porém, para vários sistemas, o cálculo das interações magnetostáticas é feito de duas maneiras: considerando-se apenas o primeiro termo da expansão multipolar e/ou aproximando as entidades magnéticas por dipolos perfeitos. Neste trabalho iremos realizar este cálculo de maneira exata, através da expansão multipolar, considerando a forma geométrica da entidade magnética. Para tal montamos um sistema macroscópico bidimensional composto por agulhas magnéticas de bússola, no qual foi automatizado a aquisição de imagens e o controle de campo magnético. No objetivo de verificar a exatidão do nosso cálculo, implementamos uma simulação utilizando o método de Monte Carlo para comparar com os resultados experimentais. Focamos o estudo sobre sistemas de duas e cinco agulhas, sendo que o primeiro permite a comparação com a solução analítica exata do problema. Observamos que a introdução dos termos de ordem mais alta na expansão multipolar modifica o potencial magnético gerado por uma agulha de bússola. A expansão multipolar do potencial mostrou que devemos considerar termos de ordem l = 1, 3 e 5, sendo que os termos de ordem par são nulos e termos l ? 7 são desprezíveis. A simulação de Monte Carlo reproduziu com fidelidade o comportamento dos sistemas experimentais, mostrando uma boa concordância entre as curvas de histerese simuladas e experimentais. Explicamos os resultados a partir do fato que a expansão multipolar introduz mínimos locais nos diagramas de energia de interação de duas partículas com campo magnético aplicado nulo. Estas regiões são conhecidas como os pontos de equilíbrio metaestáveis de um sistema magnético. Para um sistema de duas agulhas, descrevemos como os saltos na curva de histerese estão relacionados com descontinuidades na trajetória no espaço de fases de energia do sistema, criadas pelos termos de ordem mais alta. Dos nossos resultados, concluímos que para descrevermos o comportamento magnético de um sistema de agulhas de bússola, devemos levar em conta termos de ordem mais alta na expansão multipolar, bem como a geometria desta entidade / Abstract: Dipolar interactions are widely studied in magnetism, since they play a key role in most magnetic systems. However, for several systems the magnetostatic interactions calculation is done through two ways: considering only the multipole expansion first term and/or approximating the magnetic entities as perfect dipoles. In this work we will perform this calculation exactly, through the multipole expansion, considering the magnetic entities geometric shape. For such, we set up a two-dimensional macroscopic system made of magnetic compass needles, where we automated the image acquisition and the magnetic field control. In the objective of verifying our calculation accuracy, we implemented a simulation using the Monte Carlo¿s method to compare with the experimental results. We focused the study on systems of two and five needles, since the first one allowing comparing with the experimental results. We observed that the introduction of higher order terms in the multipole expansion modifies the magnetic potential generated by a compass needle. The multipole expansion showed that we need to consider order terms of l = 1, 3 and 5, with nulls even terms are and terms of l ? 7 are negligible. The Monte Carlo simulation accurately reproduced the experimental systems behaviors, exhibiting a good agreement between the simulated and experimental hysteresis curves. We explained the results through the fact that the multipole expansion introduces local minima in the two magnetic particles interaction energy diagrams with null applied magnetic field. These regions are known as metastable equilibrium points in a magnetic system. For a two-needle system, we described in detail how the hysteresis curve drops are related to trajectory discontinuities in the system energy phase space, created by the higher order terms. From our results, we conclude that to describe the magnetic behavior of a compass needle system, one must take into account higher order terms in the multipole expansion, as well as the entity geometry / Mestrado / Física / Mestre em Física / 1374983/2014 / CAPES

The combustion of petroleum-based fuels leads to the formation of several pollutants. Among them, soot particles are particularly harmful due to their severe consequences on human health. Over the past decades, strict regulations have been placed on automotive and aircraft engines to limit these particulate matter emissions. This work is primarily focused on understanding the fundamental behaviour of soot particles and their formation. Though the focus of this work is on soot formation and growth pathways, the study of the gas-phase combustion process was also an integral part to validate the mechanism. A reduced mechanism is developed with retaining the larger PAH species till coronene from KAUST-ARAMCO mechanism. Counterflow diffusion flames had emphasized the simulation of canonical configuration where the reduced mechanism is validated and the soot growth pathways are evaluated. The importance of the significant contribution of larger PAH species on the soot growth pathways in both SF and SFO flames is evident in this analysis. The sensitivity of these flames with respect to strain rates, dilution, and at higher pressures are analysed. Direct Numerical Simulation (DNS) of two-dimensional counterflow diffusion flames is conducted to understand the impact of vortex interactions on soot characteristics. The results indicate that the larger PAH species contributes to the soot formation in the air-side perturbation regimes, whereas the soot formation is dominated by the soot transport in fuel-side perturbation. The study is extended to simulate and compare coflow laminar flame using different statistical moment methods MOMIC, HMOM and CQMOM.

This paper describes basic methods used for optical character recognition. It explains all procedures of recognition from adjustment of picture, processing, feature extracting to matching algorithms. It compares methods and algorithms for character recognition obtained graphically distorted or else modified image so-called „captcha“, used in present. Further it compares method based on invariant moments and neural network as final classifier and method based on correlation between normals and recognized characters.