974 resultados para Convexity in Graphs
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This paper analyzes concepts of independence and assumptions of convexity in the theory of sets of probability distributions. The starting point is Kyburg and Pittarelli's discussion of "convex Bayesianism" (in particular their proposals concerning E-admissibility, independence, and convexity). The paper offers an organized review of the literature on independence for sets of probability distributions; new results on graphoid properties and on the justification of "strong independence" (using exchangeability) are presented. Finally, the connection between Kyburg and Pittarelli's results and recent developments on the axiomatization of non-binary preferences, and its impact on "complete" independence, are described.
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Let G be a graph that admits a perfect matching. A forcing set for a perfect matching M of G is a subset S of M, such that S is contained in no other perfect matching of G. This notion has arisen in the study of finding resonance structures of a given molecule in chemistry. Similar concepts have been studied for block designs and graph colorings under the name defining set, and for Latin squares under the name critical set. There is some study of forcing sets of hexagonal systems in the context of chemistry, but only a few other classes of graphs have been considered. For the hypercubes Q(n), it turns out to be a very interesting notion which includes many challenging problems. In this paper we study the computational complexity of finding the forcing number of graphs, and we give some results on the possible values of forcing number for different matchings of the hypercube Q(n). Also we show an application to critical sets in back circulant Latin rectangles. (C) 2003 Elsevier B.V. All rights reserved.
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Background: Understanding how clinical variables affect stress distribution facilitates optimal prosthesis design and fabrication and may lead to a decrease in mechanical failures as well as improve implant longevity. Purpose: In this study, the many clinical variations present in implant-supported prosthesis were analyzed by 3-D finite element method. Materials and Method: A geometrical model representing the anterior segment of a human mandible treated with 5 implants supporting a framework was created to perform the tests. The variables introduced in the computer model were cantilever length, elastic modulus of cancellous bone, abutment length, implant length, and framework alloy (AgPd or CoCr). The computer was programmed with physical properties of the materials as derived from the literature, and a 100N vertical load was used to simulate the occlusal force. Images with the fringes of stress were obtained and the maximum stress at each site was plotted in graphs for comparison. Results: Stresses clustered at the elements closest to the loading point. Stress increase was found to be proportional to the increase in cantilever length and inversely proportional to the increase in the elastic modulus of cancellous bone. Increasing the abutment length resulted in a decrease of stress on implants and framework. Stress decrease could not be demonstrated with implants longer than 13 mm. A stiffer framework may allow better stress distribution. Conclusion: The relative physical properties of the many materials involved in an implant-supported prosthesis system affect the way stresses are distributed.
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Network analysis naturally relies on graph theory and, more particularly, on the use of node and edge metrics to identify the salient properties in graphs. When building visual maps of networks, these metrics are turned into useful visual cues or are used interactively to filter out parts of a graph while querying it, for instance. Over the years, analysts from different application domains have designed metrics to serve specific needs. Network science is an inherently cross-disciplinary field, which leads to the publication of metrics with similar goals; different names and descriptions of their analytics often mask the similarity between two metrics that originated in different fields. Here, we study a set of graph metrics and compare their relative values and behaviors in an effort to survey their potential contributions to the spatial analysis of networks.
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We consider the numerical treatment of the optical flow problem by evaluating the performance of the trust region method versus the line search method. To the best of our knowledge, the trust region method is studied here for the first time for variational optical flow computation. Four different optical flow models are used to test the performance of the proposed algorithm combining linear and nonlinear data terms with quadratic and TV regularization. We show that trust region often performs better than line search; especially in the presence of non-linearity and non-convexity in the model.
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We consider the numerical treatment of the optical flow problem by evaluating the performance of the trust region method versus the line search method. To the best of our knowledge, the trust region method is studied here for the first time for variational optical flow computation. Four different optical flow models are used to test the performance of the proposed algorithm combining linear and nonlinear data terms with quadratic and TV regularization. We show that trust region often performs better than line search; especially in the presence of non-linearity and non-convexity in the model.
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What are ways of searching in graphs? In this class, we will discuss basics of link analysis, including Google's PageRank algorithm as an example. Readings: The PageRank Citation Ranking: Bringing Order to the Web, L. Page and S. Brin and R. Motwani and T. Winograd (1998) Stanford Tecnical Report
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El reciclaje se ha caracterizado por ser un tema importante en la última década, por el desarrollo económico, social y tecnológico que tiene consigo. Evidentemente, el sector de reciclaje se ha convertido en un sector con visión para poder conseguir un nuevo sector. Por este motivo lo que se ha querido con este trabajo de investigación es buscar nuevas manera de ver los recursos que se encuentran en cualquier lugar de las ciudades. La tesis cuenta con un sin número de argumentos que ayudarán a que las personas que lean el documento se interesen cada vez más en reutilizar los materiales que día a día encuentran. De esta manera, se puede ver una cadena de suministro, que llevará a que la materia prima que se haya mejorado sirva para realizar otro tipo de productos y genere un sostenimiento significativo a miles de personas que pueden sacarle provecho a estos materiales. Nuestros hábitos más cotidianos tienen mucho que ver con la degradación global del planeta. Actos tan rutinarios como tirar la basura sin separarla, comprar utensilios de usar y tirar o adquirir los alimentos envasados en materiales anti ecológicos o no reciclables contribuyen en gran medida a la contaminación medioambiental (Inzillo, 2000).
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RESUMO: A violência escolar, entendida como todo ato praticado de maneira isolada ou em grupo nas instituições de ensino ou em suas redondezas, envolvendo o corpo discente e/ou docente desses estabelecimentos, é uma realidade vivenciada pelos mesmos e reconhecida por toda a sociedade. Nessa perspectiva, a presente pesquisa investigou a problemática nas instituições de ensino público da Cidade de Aracaju, capital de Sergipe, Brasil. A pesquisa possibilitou demonstrar algumas das causas e consequências da violência, e entender os motivos que permitem o seu desenvolvimento em escolas públicas, campo da pesquisa, com subsídios não somente na ciência da educação como também na ciência jurídica, visto que fundamenta suas ideias em Leis e Normas que orientam e tipificam o comportamento do indivíduo na sociedade. Nesta pesquisa – de caráter exploratório e descritivo, de cunho analítico, coerente com as questões e objetivos propostos ao objeto de estudo – recorreu-se a uma pesquisa de campo com análise quali-quantitativa com resultados apresentados em gráficos, quadros e registros de ocorrência, utilizando como universo pesquisado escolas públicas municipais de Aracaju, através de questionário aplicado aos diretores e funcionários em visita “in loco”. A pesquisa é baseada em teorias que fundamentam os resultados encontrados de que o “homem é produto do meio”, isto é, a sociedade em que vive e a família têm uma influência e um papel fundamental na formação da personalidade do indivíduo, seja ele bom ou ruim. ABSTRACT: The school violence, understood as any act performed in isolation or in groups in educational institutions or in its surroundings, involving the student body and / or teaching of these establishments, is a reality faced by them and recognized throughout society. From this perspective, this research investigated the issue in public education institutions in the city of Aracaju, capital of Sergipe, Brazil. The research allow us to demonstrate some of the causes and consequences of violence, and understand the reasons that allow its development in public schools, field of research, with subsidies not only in science education as well as in legal science, since it bases its ideas on Laws and Regulations that guide and typify the behavior of the individual in society. In this research, exploratory and descriptive character, of an analytical view, consistent with the proposed objectives and issues to the object of this study - resorted to a field research with quantitative and qualitative analysis with results presented in graphs, charts and records of occurrence, using as group studied public schools in Aracaju, through a questionnaire applied to directors and employees to visit in the place. The research is based on theories that motivate the results found that “the man is the product of the environment”, this means, the society in which they live and the family have an influence and a key role in shaping the character of the individual, be it good or bad. KEYWORDS: school
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This study of Villa-Lobos’s Bachianas Brasileiras No. 9 aims at gaining insight into the decision-making processes of translating a score into a musical performance. Chapter I presents a discussion of selected issues related to interpretative analysis. Chapter II is an overview of the approaches to recording comparison deemed relevant to the present study. Chapter III is a comparative study of the vocal and string versions of Bachianas Brasileiras No. 9, while Chapter IV offers a structural analysis of the work. Chapter V compares four recordings: the composer’s own with the Orchestre National de La Radiodiffusion Française—EMI 7243 5 66964 2 6; Odaline de la Martinez and the BBC Singers, LNT 102; Michael Tilson Thomas and the New World Symphony —RCA 09026-68538-2; and my own CD, Construção, Orquestra de Câmara Theatro São Pedro- Limited Edition (live recording made on December 11, 1995 in Bayreuth, Germany). This comparison utilizes data obtained with the software Tempo. The tabulation of these results is shown in graphs that compare how matters of tempo flexibility affect each performance. This multi-faceted study shows that although painstaking analysis can lead to insightful solutions, the fleeting nature of musical performance requires an open mind and imagination to deal with the often contradictory directives of the score.
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Este estudo trata a questão da Logística na operacionalização do transporte público por ônibus da Região Metropolitana de Belém - RMB, particularmente, da concessionária Empresa Belém Rio, que atua na Capital do Pará. O foco principal foi perceber se existem indicadores de desempenho eficaz na operacionalização mais racional e equilibrada desse modal de transporte. A pesquisa foi conduzida por uma revisão bibliográfica de estudos da Logística e suas operações, como também da utilização dessa ferramenta de gestão no transporte, seguido de uma apresentação do enfoque evolutivo da RMB, com especial atenção a questão do transporte de passageiros. A metodologia foi preparada para atender à pesquisa de campo e ao estudo descritivo. Consistiu basicamente na determinação de variáveis extraídas de indicadores que tiveram por base o conceito de Logística. O questionário foi estruturado com base nessas vertentes e aplicados à uma população de 44 sujeitos, funcionários da referida empresa. Além desse procedimento foi realizada uma entrevista com a gerência executiva, na intenção não de tratamento, mas de buscar informações que pudessem subsidiar a análise. Os dados coletados no instrumento metodológico foram tratados e sistematizados em gráficos e tabelas por ferramentas estatísticas. Na análise dos dados quantificados, foi utilizada a literatura para cruzamento de informações, além do que o uso de algumas falas de respondentes. Dentro dos resultados obtidos, encontram-se observações que podem subsidiar algumas tomadas de decisão para a melhoria de desempenho da citada empresa. Além do que, disponibilizadas percepções que poderão ser utilizadas por outros estudos.
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Ajuste assimétrico de preço é observado em diversos mercados, notavelmente varejo de gasolina: um aumento de custo é passado para os consumidores mais rápido do que uma redução. Eu desenvolvo um modelo de busca dos consumidores que gera essa predição sob aversão à perda. Uma fração dos consumidores ignora os preços no mercado e pode adquirir informação a um custo, o que permite que as firmas tenham lucro com dispersão de preços. Ajuste assimétrico de preço emerge se os consumidores são aversos a perdas em relação a um preço de referência. Custos mais altos tornam os consumidores mais dispostos a procurar, mas também diminui as chances de encontrar preços baixos, gerando uma relação custo-preço convexa.
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It´s been motivating motivated by the current rulers as an energy solution the use of the biodiesel as source of energy, that doesn't damage the environment and promotes the development of the areas where the base plant are grown. The process of production of the biodiesel, starting from the castor oil plant and its derivers, generates a known product as castor oil plant pie that has been used as fertilizer. Once disintoxicated, it can serve as animal ration, because it contains high content of proteins, presenting larger joined value. The disintoxication process, can be obtained through the process of drying the pie with the construction and use of models of dryers capable to elevate the temperature of the castor oil plant pie to approximately 60ºC.In this temperature the product tends to eliminate the ricina, with the aid of an aqueous solution of hydroxide of calcium, or still reach higher temperatures to make the disintoxication without a chemical treatment. It was made a bibliographical research about known processes of disintoxication of the castor oil plant pie from the autoclave use to the drying direct exposure to the sun. Starting from the state of the art and identification of the object, it was chosen solar dryers to eliminate the ricina. It was applied two types of solar dryers: the one of solar direct exposure, and the one with concentrador. The castor oil plant pie was separated in samples, with measurement of its initial mass, codified and placed in the dryers. The results were presented in graphs and tables forms, with the values of temperatures noticed. It was noticed the variations of temperature and the relationships analyzed related with the ricina content eliminated from the pie. The analysis of the ricina content was accomplished by Embrapa - Campina Grande, by eletroforese method. The analysis of the result of considering the content of ricina of the samples. It was observed that, we obtained lower rate of ricina in samples that had larger drying time and average value temperature above 60ºC. Comparing with the ones submitted to higher temperatures and in a shorter period of time. It was possible to evaluate the efficiency of the dryers in the desintoxication process of the samples, as well as the type of more appropriate dryer for the drying pie process. Finally, it was concluded that the solar dryer with concentrador presents higher values temperatures than the direct exposure one. So, it´s being more opportune applied in the castor oil plant pie drying process. However, more than one hour for drying time is needed
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This paper presents the virtual environment implementation for project simulation and conception of supervision and control systems for mobile robots, that are capable to operate and adapting in different environments and conditions. This virtual system has as purpose to facilitate the development of embedded architecture systems, emphasizing the implementation of tools that allow the simulation of the kinematic conditions, dynamic and control, with real time monitoring of all important system points. For this, an open control architecture is proposal, integrating the two main techniques of robotic control implementation in the hardware level: systems microprocessors and reconfigurable hardware devices. The implemented simulator system is composed of a trajectory generating module, a kinematic and dynamic simulator module and of a analysis module of results and errors. All the kinematic and dynamic results shown during the simulation can be evaluated and visualized in graphs and tables formats, in the results analysis module, allowing an improvement in the system, minimizing the errors with the necessary adjustments optimization. For controller implementation in the embedded system, it uses the rapid prototyping, that is the technology that allows, in set with the virtual simulation environment, the development of a controller project for mobile robots. The validation and tests had been accomplish with nonholonomics mobile robots models with diferencial transmission. © 2008 IEEE.