Made available in DSpace on 2016-12-12T20:25:11Z (GMT). No. of bitstreams: 1 Nestor Juvenal G Terra Dias.pdf: 2791426 bytes, checksum: ca6d2cf5b36479b660a86c2196aa3b25 (MD5) Previous issue date: 2014-07-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main objective of this work was to obtain an alternative formulation for the so-called Hermitian 2-simplex type-(3) elements and enrich this formulation by adding functions with null value on all the nodes of the element, however with unitary partial derivatives one node. The conventional Hermitian element is an old element with degree p=3 and the degrees of freedom are the displacements and the partial derivatives in each node of the element. The element formulated in this work and their enriched versions have C0 continuity (C1 continuity is assured only at the element nodes). The formulation of the elements is based on the Principle of Minimum Potential Energy and because it is a displacement formulation, the prescribed Neumann (partial derivatives) or the Cauchy-Robin (mixed) boundary conditions are satisfied without any difficulty at the boundary nodes. Stresses and/or fluxes are obtained without any additional post-processing of finite element solution and with precision similar to the precision obtained for displacements. In this work these elements were applied to the solution of various problems of plane elasticity, axial-symmetric elasticity, free vibration of membranes and potential problems. The main emphasis in these analyzes was to study the rates of convergence obtained with homogeneous meshes and distorted meshes. Another aspect studied was the convergence for material locking problems (EPD) and special attention was given to the analysis of error in stress (or fluxes). After several comparisons made throughout this work it was concluded that the results obtained with this type of element is better than a large majority of triangular elements available in the literature. / Objetivo principal deste trabalho foi obter uma formulação alternativa para os chamados elementos Hermitianos 2-simplex do tipo (3) e enriquecer esta formulação adicionando funções com valor nulo em todos os nós do elemento, porém com derivadas parciais unitárias em apenas um destes nós. O elemento Hermitiano convencional é um elemento antigo na literatura, possui grau p=3 e os graus de liberdade do elemento são os deslocamentos e suas derivadas parciais em cada nó. O elemento formulado neste trabalho e sua versão enriquecida possuem continuidade C0 (a continuidade C1 só é assegurada nos nós do elemento). A formulação dos elementos é baseada no Princípio da Mínima Energia Potencial e por se tratar de uma formulação de deslocamento as condições de contorno de derivadas (Neumann) ou mistas (Cauchy-Robin) que são prescritas no contorno são satisfeitas sem nenhuma dificuldade. As tensões e/ou fluxos são obtidos sem nenhum pós-processamento adicional e com precisão semelhante à dos deslocamentos. Neste trabalho estes elementos foram aplicados para a solução de diversos problemas da elasticidade plana e axi-simétrica, problemas de vibração livre de membranas e problemas de potencial. A ênfase principal nestas análises foi o estudo das taxas de convergência com malhas homogêneas e com malhas distorcidas. Outro aspecto estudado foi a convergência para os problemas de locking de Poisson e especial atenção foi dada para as análises de erro em tensões (ou fluxos) pontuais que é o ponto forte deste tipo de elemento. Após diversas comparações realizadas ao longo deste trabalho concluiu-se que os resultados obtidos com este tipo de elemento são melhores do que a grande maioria de elementos triangulares disponíveis na literatura.

Ranking a set of candidates or items from pair-wise comparisons is a fundamental problem that arises in many settings such as elections, recommendation systems, sports team rankings, document rankings and so on. Indeed it is well known in the psychology literature that when a large number of items are to be ranked, it is easier for humans to give pair-wise comparisons as opposed to complete rankings. The problem of ranking from pair-wise comparisons has been studied in multiple communities such as machine learning, operations research, linear algebra, statistics etc., and several algorithms (both classic and recent) have been proposed. However, it is not well under-stood under what conditions these different algorithms perform well. In this thesis, we aim to fill this fundamental gap, by elucidating precise conditions under which different algorithms perform well, as well as giving new algorithms that provably perform well under broader conditions. In particular, we consider a natural statistical model wherein for every pair of items (i; j), there is a probability Pij such that each time items i and j are compared, item j beats item i with probability Pij . Such models, which we summarize through a matrix containing all these pair-wise probabilities, have been used explicitly or implicitly in much previous work in the area; we refer to the resulting matrix as the pair-wise preference matrix, and elucidate clearly the crucial role it plays in determining the performance of various algorithms. In the first part of the thesis, we consider a natural generative model where all pairs of items can be sampled and where the underlying preferences are assumed to be acyclic. Under this setting, we elucidate the conditions on the pair-wise preference matrix under which popular algorithms such as matrix Borda, spectral ranking, least squares and maximum likelihood under a Bradley-Terry-Luce (BTL) model produce optimal rankings that minimize the pair-wise disagreement error. Specifically, we derive explicit sample complexity bounds for each of these algorithms to output an optimal ranking under interesting subclasses of the class of all acyclic pair-wise preference matrices. We show that none of these popular algorithms is guaranteed to produce optimal rankings for all acyclic preference matrices. We then pro-pose a novel support vector machine based rank aggregation algorithm that provably does so. In the second part of the thesis, we consider the setting where preferences may contain cycles. Here, finding a ranking that minimizes the pairwise disagreement error is in general NP-hard. However, even in the presence of cycles, one may wish to rank 'good' items ahead of the rest. We develop a framework for this setting using notions of winners based on tournament solution concepts from social choice theory. We first show that none of the existing algorithms are guaranteed to rank winners ahead of the rest for popular tournament solution based winners such as top cycle, Copeland set, Markov set etc. We propose three algorithms - matrix Copeland, unweighted Markov and parametric Markov - which provably rank winners at the top for these popular tournament solutions. In addition to ranking winners at the top, we show that the rankings output by the matrix Copeland and the parametric Markov algorithms also minimize the pair-wise disagreement error for certain classes of acyclic preference matrices. Finally, in the third part of the thesis, we consider the setting where the number of items to be ranked is large and it is impractical to obtain comparisons among all pairs. Here, one samples a small set of pairs uniformly at random and compares each pair a fixed number of times; in particular, the goal is to come up with good algorithms that sample comparisons among only O(nlog(n)) item pairs (where n is the number of items). Unlike existing results for such settings, where one either assumes a noisy permutation model (under which there is a true underlying ranking and the outcome of every comparison differs from the true ranking with some fixed probability) or assumes a BTL or Thurstone model, we develop a general algorithmic framework based on ideas from matrix completion, termed low-rank pair-wise ranking, which provably produces an good ranking by comparing only O(nlog(n)) pairs, O(log(n)) times each, not only for popular classes of models such as BTL and Thurstone, but also for much more general classes of models wherein a suitable transform of the pair-wise probabilities leads to a low-rank matrix; this subsumes the guarantees of many previous algorithms in this setting. Overall, our results help to understand at a fundamental level the statistical properties of various algorithms for the problem of ranking from pair-wise comparisons, and under various natural settings, lead to novel algorithms with improved statistical guarantees compared to existing algorithms for this problem.

The target of the this diploma thesis called ''The Napoleon's theorem'' is a detailed concentration on this theorem, where the process of so called ''regularization'' is described. Under the investigation of the Napoleon's theorem this diploma thesis is concerned with a lot of proofs, properties and then their generalization in a plane and in space. Pictures, which can help the reader to understand this problem are supplemented in this diploma thesis.

The shifting focus in the role of academic libraries entail a better understanding, awareness and responsiveness to the needs of the library users. In an environment of change and an age of accountability academic libraries have to determine and demonstrate the impact their resources and services are having on their institutional mission. Service quality is not based exclusively on the perception of the librarians, but also dependent on the perception of users. Only customers judge quality; all other judgments are essentially irrelevant" (Zeithaml, Parasuraman, Berry 1999). The reason of this study was to assess quality in the library and to determine the perceptions of the Vaal Triangle Campus Library users as they relate to quality service and to develop a model to improve service quality. The aim was to determine library users' minimum expectations for services, their desired level of service and then to identify the extent of service they currently perceive on three dimensions of service quality: affect of service, library as place and access to information. A triangulation, mixed method research methodology was employed in this study. Data was collected using focus group as well as individual interviews and the LibQUAL questionnaire. Purposive sampling was used to determine participants for the interviews while a total market survey was employed for the questionnaire respondents. Findings indicate that there is a gap between the users' expectations and perception of service quality. The results indicate that there are variations within the different user groups regarding the expectations and perceptions of service quality at the Vaal Triangle Campus library. In view of the findings, the study concluded by developing a service quality model based on Deming's PDCA cycle, the ISO model and the Hoshin Kanri process / Information Science / M. Inf.

Orientador: Prof. Dr. Jerônimo Cordoni Pellegrini / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2014. / O objetivo deste trabalho é dar uma visão bem ampla do triângulo aritmético. Primeiramente esse texto tem um caráter histórico, a partir do texto original de 1654, é apresentado um estudo da visão que Pascal tinha do triângulo e onde ele o aplicava. Seu texto foi colocado numa linguagem mais moderna que o original, mas mantendo toda a sua linha de raciocínio. Além disso, esse texto reúne e demonstra suas propriedades e usos. Cada ideia é exposta de uma maneira diferente ou mais detalhada do que encontramos na literatura. Algumas propriedades são bem conhecidas, enquanto outras normalmente não estão associadas ao triângulo aritmético, como partição de combinações, matrizes de Pascal incluindo forma quadrática e também o plano aritmético, que expande o triângulo aritmético. Por fim, temos uma visão de como o triângulo pode ser usado dentro da sala de aula numa linguagem que será útil tanto para os professores quanto para os alunos. / The objective of this paper is to provide a very broad view on the arithmetic triangle. First off, this text has a historic character. Based upon the original text of Pascal from 1654, a study of Pascal¿s view on the triangle and where he applied it is set forth. Despite the fact that the text was converted into a more modern language than the original, the entire author¿s stream of thought was preserved. Furthermore, this text gathers and demonstrates its properties and usages. Each idea is put across in a different manner or in a more detailed form than we find in the literature. Some properties are well known, while others are not commonly associated with the arithmetic triangle, as partitioning of combinations, Pascal Matrixes including the quadratic form and also the arithmetic plane, which expands the arithmetic triangle. Finally, we have an insight on how the triangle can be used inside the classroom, in a language which will be useful both for the teachers and for the students.

Orientador: Prof. Dr. Daniel Miranda Machado / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2016. / Este trabalho foi desenvolvido para auxiliar alunos ingressantes no ensino superior, revisando t opicos da trigonometria e de funcoes trigonometricas, podendo auxiliar tambem alunos do ensino medio, professores ou interessados no assunto. Este trabalho parte de estudos iniciais da trigonometria e aborda de maneira simples a construcao de graficos de funcoes trigonometricas da forma f(x) = a+b. sen(c.x+d), onde a, b, c e d sao coeficientes reais que alteram a amplitude, a imagem e período das funcões trigonometricas. Sao deduzidas as formulas de adicao de arcos, que auxiliam na demonstracao de outras equacoes, como por exemplo o teorema das relacoes entre as cordas de circunferencia, de Ptolomeu,. Tambem apresentamos aplicacoes da trigonometria aos triangulos nao retangulos, como a lei dos senos e a lei dos cossenos, utilizada tambem para um triangulo qualquer, auxiliando na demonstracao de equacoes importantes, como por exemplo da força resultante, em Física. / In this work we analyze a simplified version of the Monopoly game using a Markov chain model with discrete time parameter. In the first chapter we discuss on the Classical Theory of Probability, bringing the most important results for this study, preceded by a brief introduction about the ideas of chance throughout the history of mankind and leading thinkers involved in the development of this theory. In the second chapter we make a historical introduction to stochastic processes and Markov chains; then we explain the fundamental concepts of Markov Chains, putting some examples and finally discussing the ergodicity of a Markov chain. In the third chapter, after a brief explanation of the emergence and subsequent evolution of the Monopoly game throughout the twentieth century, we analyze the dynamics of the game by the model of a Markov chain, using as an object of study a simpler version of the game in question.

Orientador: Prof. Dr. Márcio Fabiano da Silva / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2017. / Neste trabalho,apresentamos um estudos obre os triângulos que possuem lados e área de medidas inteiras,doravante chamados de Triângulos Heronianos, muito estudados na teoria dos números a partir da fórmula de Heron,que relaciona a área de um triângulo aos seus três lados.Este tema traz o desafio de se encontrar triplas de inteiros que satisfaçam as condições da fórmula de Heron, problema este já resolvido desde o século VI pelo matemático indiano Brahmagupta por meio de parametrizações. Outro fator enriquecedor deste estudo é que esta classe de triângulos apresenta diversas propriedades que, apesar de não serem óbvias,podem ser demonstradas com conceitos de matemática básica,viabilizando o seu ensino nas aulas regulares de matemática. / In this work, we present a study on the triangles that have sides and area that are all integers, hance called Heronian Triangles, well studied in nnumber theory based on Heron¿s formula, which relates the area of a triangle to its three sides.This theme brings the challenge of finding triples of integers that satisfy the conditions of Heron¿s formula, a problem that has been solved since the sixth century by the Indian mathematician Brahmagupta by means of parametrizations. Another enriching factor of this study is that this class of triangles presents several properties that,although not obvious, can be demonstrated with concepts of basic mathematics,facilitating their teaching in regular math classes.

O presente estudo é uma investigação empírica de natureza qualitativa e tem por objetivo comparar as características das fraudes praticadas por meio de manipulação nas demonstrações contábeis das empresas Daslu, Kmart e Avestruz Master. Buscou-se verificar diferenças entre fraudes no Brasil e nos Estados Unidos, no que se refere às motivações e finalidades da ação fraudulenta, aos métodos de manipulação contábil utilizados e à governança corporativa adotada pelas empresas. O trabalho foi desenvolvido seguindo a metodologia do estudo de casos múltiplos, utilizando-se um protocolo, que contemplou os procedimentos e as regras gerais obedecidas na pesquisa, com a função de incrementar a confiabilidade do estudo e orientar o trabalho do pesquisador. A seleção dos casos estudados foi feita com base em pesquisas anteriores, que mencionaram fraudes praticadas no Brasil e nos Estados Unidos, na última década. Os resultados indicam que as fraudes apresentaram diferenças na natureza e na autoria dos atos fraudulentos, com evidências da aplicação das teorias do triângulo da fraude (TTF) e dos escândalos corporativos (TEC). Considerando que as corporações brasileiras estudadas possuíam sistema de governança corporativa concentrado, similar ao de empresas europeias, as diferenças observadas nas fraudes investigadas podem ser explicadas pela teoria dos escândalos corporativos, defendida por Coffee Jr. (2005). / The present study is an empirical research of qualitative nature and aims to compare the characteristics of fraud committed by means of manipulation in the financial statements of Daslu, Kmart and Avestruz Master companies. It has been trying to check differences between fraud in Brazil and in United States with regard to the motivations and purposes of the fraudulent action, accounting handling methods used and to corporate governance adopted by companies. The work was developed, following the methodology of study of multiple cases, using a case study protocol, which included general rules and procedures observed in the survey, with the function of increasing the reliability of the study and guide the researcher work. The selection of studied cases was based on previous research that mentioned fraud practiced in Brazil and in United States in last decade. The results indicate that frauds have showed differences in fraud operation and in its author, with evidence of the application of fraud triangle (TTF) and the corporate scandals (TEC) theories. Whereas the corporations studied had corporate governance system similar to that of European companies, the observed differences in investigated frauds can be explained by the theory of corporate scandals (TEC) defended by Coffee Jr. (2005).

The topic of this diploma thesis is the possibility of detection of errors and fraud in accounting. The aim of the thesis is to evaluate how the user of the financial statements is able to assess the risk of accounting errors and frauds only from freely available financial statements and other information. In this work are used selected detection models - Beneish model, CFEBT model, Jones nondiscretionary accruals and CFEBT risk triangle of accounting errors and frauds are used. In addition, Altman's Z-score was calculated. This diploma thesis is focused on the reporting capacity of financial statements for stakeholders and other external users because it has a significant impact on their economic decision-making. This thesis analyses the published and audited financial statements from the perspective of a user who does not have access to more detailed supporting documentation. The first part of the thesis is theoretical. This section describes the definitions, history, causes, effects and techniques of creative accounting, as well as selected detection models. These should help identify manipulations in the financial statements. Methods and analyses are described in the methodical part. The third part presents the results of the analyses, including their comments and assessments. Finally, it is assessed if the financial statements of the selected entity contain manipulated data, i.e. what is the possibility of manipulation of the accounting data. Evaluates the possibility of analysing financial statements by an external user who only has freely available information and data.

Made available in DSpace on 2016-06-02T20:29:22Z (GMT). No. of bitstreams: 1 5363.pdf: 6155796 bytes, checksum: 5fcc940d5e974f06e05cfe033a89fcd9 (MD5) Previous issue date: 2013-08-19 / Financiadora de Estudos e Projetos / In this paper, I intend to report the experience of implementing an activity in some classes in a public school of the city of Ribeirão Preto, state of São Paulo, where it was made an approach to the subject "Notable Points of a Triangle" by using the software GeoGebra like as a tool for teaching and learning. The aim is to analyze students' reactions and the interaction of the same at the presentation of the content using this software. Also a comparison of the progress is made with regard to student learning through the production and execution of activities, consisting of scripts/walkthroughs. The methodology used is the didactic engineering. Working in pairs, due to the limited amount of computers in the computer lab of the school, improved academic relations between some students, arising naturally an exchange of ideas and awakening a spirit of collaboration in a very healthy learning space. At the end of the study the author concluded that activities using computing resources as an educational tool optimizes the process of teaching and learning. / Neste trabalho, pretendo relatar a experiência de aplicação de uma atividade em algumas aulas, em uma escola municipal da prefeitura de Ribeirão Preto, estado de São Paulo, onde foi feita a abordagem do assunto Pontos Notáveis de um Triângulo utilizando o software GeoGebra como ferramenta de ensino e aprendizagem. O objetivo é analisar as reações dos alunos e a interação dos mesmos, por ocasião da apresentação do conteúdo utilizando este software. Também é feita uma comparação dos avanços obtidos no tocante à aprendizagem dos alunos através das produções e da execução de atividades, constituídas de roteiros/instruções passo a passo. A metodologia utilizada é a engenharia didática. O trabalho em duplas, por conta da quantidade limitada de computadores existentes no laboratório de informática da escola, estreitou as relações acadêmicas entre alguns alunos, fazendo surgir naturalmente uma troca de ideias e despertando um espírito de colaboração muito saudáveis num espaço de aprendizagem. Ao final da pesquisa o autor concluiu que atividades utilizando recursos computacionais como ferramenta educativa otimizam o processo de ensino e aprendizagem.