Thesis (doctoral)--Rheinische Friedrich-Wilhelms-Universität Bonn, 2000. / Includes bibliographical references (p. 59-61).

Thesis (Ph. D.)--University of Florida, 2005. / Title from title page of source document. Document formatted into pages; contains 97 pages. Includes vita. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 162-164).

Thesis (Ocean E)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1981. / Supervised by J. Kim Vandiver. Includes bibliographical references (p. 169-175).

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2009. / Includes bibliographical references (leaves 84-89). Also available online.

Made available in DSpace on 2015-03-03T11:52:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-29Bitstream added on 2015-03-03T12:07:38Z : No. of bitstreams: 1 000807504.pdf: 728966 bytes, checksum: a493ed42a1f60efda334409e19dc95d7 (MD5) / Este trabalho está dividido em quatro partes. Na primeira parte, apresentamos uma breve introdução ao estudo dos chamados sólitons, os quais correspondem a certas soluções de equações de onda não-lineares. Mostraremos as importantes características e propriedades destas classes de configurações. Em adição, vamos mostrar dois exemplos de configurações do tipo sólitons, as quais envolvem campos escalares em 1+1 dimensões. Além disso, também apresentamos uma maneira de caracterizar soluções do tipo sólitons, qual seja a chamada carga topológica. Na segunda parte do nosso trabalho, estudamos a chamada entropia configuracional para uma classe de modelo que apresentam dois campos escalares auto-interagentes que suportam configurações do tipo kinks e lumps. Mostramos que, apesar da energia das configurações serem degeneradas, elas têm uma configuração favorita devido a sua entropia configuracional. Então, apresentamos as consequências gerais deste valor preferido de entropia para a estrutura das configurações. Também mostraremos que nossos resultados estão em perfeito acordo com aqueles numéricos. Já na terceira parte, apresentaremos uma classe de sólitons viajantes em sistemas com violações das simetrias de Lorentz. No caso de cenários envolvendo violações de Lorentz é usual construir configurações solitônicas estáticas. Aqui mostramos mostrar que é possível construir alguns sólitons viajantes os quais, como deveria ser esperado, não podem ser mapeados em configurações estáticas através do boost de Lorentz devido à quebra explícita desta simetria. Ademais, no modelo estudado, encontramos um conjunto completo de soluções. Neste caso, mostraremos que as soluções apresentam um limite crítico controlado pela escolha de uma constante arbitrária de integração. Na parte final do trabalho, discutimos... (Resumo completo, clicar acesso eletrônico abaixo) / This thesis is divided in four parts. In the first part, we present a brief review of the study of solitons, which are solutions of nonlinear differential equations. Furthermore, we show the important characteristics and properties of these classes of configurations. In the second part, we have investigated the measure of the configurational entropy of some classes of models which comprises two interacting scalar fields. We found that the best configuration of the fields has a preferred value. In the third part, we present a new class of traveling solitons in Lorentz-violating systems. This is done by using nonlinear models in twodimensional space-time of two interacting scalar fields in Lorentz-violating scenarios. Here we show that it is possible to construct some solitons with position and time dependence which, as it should be expected, can not be mapped into a static configuration by means of Lorentz boosts due to its explicit breaking. Finally, we discuss the impact of the breaking of the Lorentz symmetry on the usual oscillons, the so-called flat-top oscillons, and on the breathers. Our analysis is performed by using a Lorentz violation scenario rigorously derived in the literature. We show that the Lorentz violation is responsible for the origin of a kind of deformation of the configuration, where the field configuration becomes oscillatory in a localized region near its maximum value. Furthermore, we show that the Lorentz breaking symmetry produces a displacement of the oscillon along the spatial direction, the same feature is present in the case of breathers

Orientador: Álvaro de Souza Dutra / Coorientador: Marcelo Gleiser / Banca: Marcelo Batista Hott / Banca: Denis Dalmazi / Banca: Dionisio Bazeia Filho / Banca: Carlos Alberto Santos de Almeida / Resumo : Este trabalho está dividido em quatro partes. Na primeira parte, apresentamos uma breve introdução ao estudo dos chamados sólitons, os quais correspondem a certas soluções de equações de onda não-lineares. Mostraremos as importantes características e propriedades destas classes de configurações. Em adição, vamos mostrar dois exemplos de configurações do tipo sólitons, as quais envolvem campos escalares em 1+1 dimensões. Além disso, também apresentamos uma maneira de caracterizar soluções do tipo sólitons, qual seja a chamada carga topológica. Na segunda parte do nosso trabalho, estudamos a chamada entropia configuracional para uma classe de modelo que apresentam dois campos escalares auto-interagentes que suportam configurações do tipo kinks e lumps. Mostramos que, apesar da energia das configurações serem degeneradas, elas têm uma configuração favorita devido a sua entropia configuracional. Então, apresentamos as consequências gerais deste valor preferido de entropia para a estrutura das configurações. Também mostraremos que nossos resultados estão em perfeito acordo com aqueles numéricos. Já na terceira parte, apresentaremos uma classe de sólitons viajantes em sistemas com violações das simetrias de Lorentz. No caso de cenários envolvendo violações de Lorentz é usual construir configurações solitônicas estáticas. Aqui mostramos mostrar que é possível construir alguns sólitons viajantes os quais, como deveria ser esperado, não podem ser mapeados em configurações estáticas através do boost de Lorentz devido à quebra explícita desta simetria. Ademais, no modelo estudado, encontramos um conjunto completo de soluções. Neste caso, mostraremos que as soluções apresentam um limite crítico controlado pela escolha de uma constante arbitrária de integração. Na parte final do trabalho, discutimos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This thesis is divided in four parts. In the first part, we present a brief review of the study of solitons, which are solutions of nonlinear differential equations. Furthermore, we show the important characteristics and properties of these classes of configurations. In the second part, we have investigated the measure of the configurational entropy of some classes of models which comprises two interacting scalar fields. We found that the best configuration of the fields has a preferred value. In the third part, we present a new class of traveling solitons in Lorentz-violating systems. This is done by using nonlinear models in twodimensional space-time of two interacting scalar fields in Lorentz-violating scenarios. Here we show that it is possible to construct some solitons with position and time dependence which, as it should be expected, can not be mapped into a static configuration by means of Lorentz boosts due to its explicit breaking. Finally, we discuss the impact of the breaking of the Lorentz symmetry on the usual oscillons, the so-called flat-top oscillons, and on the breathers. Our analysis is performed by using a Lorentz violation scenario rigorously derived in the literature. We show that the Lorentz violation is responsible for the origin of a kind of deformation of the configuration, where the field configuration becomes oscillatory in a localized region near its maximum value. Furthermore, we show that the Lorentz breaking symmetry produces a displacement of the oscillon along the spatial direction, the same feature is present in the case of breathers / Doutor

Orientador: Gonçalo Amarante Guimarães Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T21:36:16Z (GMT). No. of bitstreams: 1 Sampaio_ClaudioLuisMarques_M.pdf: 2335220 bytes, checksum: 0b5237faca34d31d6e2743587c4b32fd (MD5) Previous issue date: 2010 / Resumo: Um problema recorrente em Filogenética é saber de antemão que melhores tamanhos de genes ou proteínas se deve ter para a construção de dendrogramas mais precisos. Neste trabalho, examinamos quais os efeitos de variados tamanhos de um alinhamento conhecido na qualidade da inferência de filogenia, em particular a filogenia dos fungos, utilizando 198 táxons fungais e 16 de grupo externo. Adicionalmente, calculamos a entropia de Shannon de cada ponto do alinhamento e fizemos iterações semelhantes por seus limiares. Para isto construímos um programa open-source baseado no toolkit bioperl que calcula estes dados. Concluímos que tanto para as iterações por tamanho quanto os para entropia, os limiares ideais são aquém do tamanho total do gene, podendo justificar uso de drafts de seqüenciamentos em inferências filogenéticas usando um pequeno número de regras / Abstract: A recurring issue in phylogenetics is knowing beforehand which best sizes for genes or proteins one should have for building more accurate cladograms. Herein we examine the effects or varying sizes of a known aligment on the quality of its inferred phylogeny, specifically considering the fungi phylogeny by using 198 fungal taxa plus 16 outgroup taxa. Additionally, we calculate the Shannon entropy of each point of the alignment and iterate similarly by its thresholds. To that end, we developed an open-source software based on the bioperl toolkit to calculate this data. Finally, we concluded that either for the size iterations or for the entropy iterations, the ideal thresholds are below the gene full size, justifying the use of sequencing drafts in phylogenetic inferrences using a handful of rules / Mestrado / Bioinformatica / Mestre em Genética e Biologia Molecular

Vehicles of today contain many advanced and complex systems, systems that make it hard for the mechanics working with them to keep an overview. In addition, new systems are introduced at an increasingly higher pace, which makes it hard or impossible for the mechanics to keep a both broad and deep competence. Consequently, to maintain a fast and efficient repair process, there is a need for computer-aided diagnosis. In this thesis we develop a method for choosing the best "next action" in a repair process, using observations and a probability model. We describe the state of the system as a belief-state, a probability distribution over the faults that can occur on the system. An AND/OR-tree is used when searching for the optimal repair plan. We use entropy to speed up the algorithms. To avoid expensive validation actions, the system functionality is only inspected if the probability of having a fault free system is above a certain level. The method is compared with two implementations of an existing method, with good results. The method can favorably be used on systems with many possible faults.

The maximum entropy principle, pioneered by Jaynes, provides a method for finding the least biased probability distribution for the description of a system or process, given as prior information the expectation values of a set (in general, a small number) of relevant quantities associated with the system. The maximum entropy method was originally advanced by Jaynes as the basis of an information theory inspired foundation for equilibrium statistical mechanics. It was soon realised that the method is very useful to tackle several problems in physics and other fields. In particular it constitutes a powerful tool for obtaining approximate and sometimes exact solutions to several important partial differential equations of theoretical physics. In Chapter 1 a brief review of Shannon’s information measure and Jaynes’ maximum entropy formalism is provided. As an illustration of the maximum entropy principle a brief explanation of how it can be used to derive the standard grand canonical formalism in statistical mechanics is given. The work leading up to this thesis has resulted in the following publications in peer-review research journals: • J.-H. Schönfeldt and A.R. Plastino, Maximum entropy approach to the collisional Vlasov equation: Exact solutions, Physica A, 369 (2006) 408-416, • J.-H. Schönfeldt, N. Jimenez, A.R. Plastino, A. Plastino and M. Casas, Maximum entropy principle and classical evolution equations with source terms, Physica A, 374 (2007) 573-584, • J.-H. Schönfeldt, G.B. Roston, A.R. Plastino and A. Plastino, Maximum entropy principle, evolution equations, and physics education, Rev. Mex. Fis. E, 52 (2)(2006) 151-159. Chapter 2 is based on Schönfeldt and Plastino (2006). Two different ways for obtaining exact maximum entropy solutions for a reduced collisional Vlasov equation endowed with a Fokker-Planck like collision term are investigated. Chapter 3 is based on Schönfeldt et al. (2007). Most applications of the maximum entropy principle to time dependent scenarios involved evolution equations exhibiting the form of a continuity equations and, consequently, preserving normalization in time. In Chapter 3 the maximum entropy principle is applied to evolution equations with source terms and, consequently, not preserving normalization. We explore in detail the structure and main properties of the dynamical equations connecting the time dependent relevant mean values , the associated Lagrange multipliers, the partition function, and the entropy of the maximum entropy scheme. In particular, we compare the H-theorems verified by the maximum entropy approximate solutions with the Htheorems verified by the exact solutions. Chapter 4 is based on Schönfeldt et al. (2006). In chapter 4 it is discussed how the maximum entropy principle can be incorporated into the teaching of aspects of theoretical physics related to, but not restricted to, statistical mechanics. We focus our attention on the study of maximum entropy solutions to evolution equations that exhibit the form of continuity equations (eg. Liouville equation, the diffusion equation the Fokker-Planck equation, etc.). / Dissertation (MSc (Physics))--University of Pretoria, 2008. / Physics / MSc / unrestricted