1000 resultados para INFERÊNCIA ESTATÍSTICA


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Starting from the idea that the result of the Humean analysis of causal inferences must be applied coherently to the remaining part of his work, including its moral theory, the present master thesis aims at investigating whether Hume´s moral philosophy is essentially based on feeling, or whether this would not be rather essentially a consequence of our causal inferences in human actions and deliberations. The main idea consists in showing that our moral inferences, to the extent that they are for Hume empirical , depend on our belief in a connexion between something which has been previously observed and something which is not being observed ( but that it is expected to occur or to be observed in the future). Thus, this very belief must base our moral inferences concerning the actions and deliberations of the individuals. Therefore, must e o ipso induce us to associate actions and behaviors, as well as character and moral claims of men to certain moral feelings. Accordingly, the thesis is unfolded in three chapters. In the first chapter Hume´s theory of the perception is reported as essential part of the explanation or the principles that bind ideas in our mind and constitute our inferences. In the second chapter, the Humean analysis of causal inferences is presented and the way they contribute in the formation of our moral inferences is explained. In the third and last chapter, the formation of our moral inferences and the real contribution of the doctrine of freedom and necessity for the examination or our actions are analysed and discussed.

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In the 20th century, the acupuncture has spread on occident as a complementary practice of heath care. This fact has motivated the international scientific community to invest in research that seek to understand why acupuncture works. In this work we compare statistically volt age fluctuation of bioelectric signals caught on the skin at an acupuncture point (IG 4) another nearby on acupuncture point. The acquisition of these signals was performed utilizing an electronic interface with a computer, which was based on an instrumentation amplifier designed with adequate specifications to this end. On the collected signals from a sample of 30 volunteers we have calculated major statistics and submitted them to pairing t-test with significance leveI a = O, 05. We have estimated to bioelectric signals the following parameters: standard deviation, asymmetry and curtose. Moreover, we have calculated the self-correlation function matched by on exponential curve we have observed that the signal decays more rapidly from a non-acupoint then from an acupoint. This fact is an indicative of the existence of information in the acupoint

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O processamento de registros sísmicos é uma tarefa muito importante dentro da Geofísica e que representa um desafio permanente na exploração de petróleo. Embora esses sinais forneçam uma imagem adequada da estrutura geológica do subsolo, eles são contaminados por ruídos e, o ground roll é a componente principal. Este fato exige um esforço grande para o desenvolvimento de metodologias para filtragem, Dentro desse contexto, este trabalho tem como objetivo apresentar um método de remoção do ruído ground roll fazendo uso de ferramentas da Física Estatística. No método, a Análise em Ondeletas é combinada com a Transformada de Karhunen-Loève para a remoção em uma região bem localizada. O processo de filtragem começa com a Decomposição em Multiescala. Essa técnica permite uma representação em tempo-escala fazendo uso das ondeletas discretas implementadas a filtros de reconstrução perfeita. O padrão sísmico original fica representado em multipadrões: um por escala. Assim, pode-se atenuar o ground roll como uma operação cirúrgica em cada escala, somente na região onde sua presença é forte, permitindo preservar o máximo de informações relevantes. A atenuação é realizada pela definição de um fator de atenuação Af. Sua escolha é feita pelo comportamento dos modos de energia da Transformada de Karhunen-Loève. O ponto correspondendo a um mínimo de energia do primeiro modo é identificado como um fator de atenuação ótimo

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Systems whose spectra are fractals or multifractals have received a lot of attention in recent years. The complete understanding of the behavior of many physical properties of these systems is still far from being complete because of the complexity of such systems. Thus, new applications and new methods of study of their spectra have been proposed and consequently a light has been thrown on their properties, enabling a better understanding of these systems. We present in this work initially the basic and necessary theoretical framework regarding the calculation of energy spectrum of elementary excitations in some systems, especially in quasiperiodic ones. Later we show, by using the Schr¨odinger equation in tight-binding approximation, the results for the specific heat of electrons within the statistical mechanics of Boltzmann-Gibbs for one-dimensional quasiperiodic systems, growth by following the Fibonacci and Double Period rules. Structures of this type have already been exploited enough, however the use of non-extensive statistical mechanics proposed by Constantino Tsallis is well suited to systems that have a fractal profile, and therefore our main objective was to apply it to the calculation of thermodynamical quantities, by extending a little more the understanding of the properties of these systems. Accordingly, we calculate, analytical and numerically, the generalized specific heat of electrons in one-dimensional quasiperiodic systems (quasicrystals) generated by the Fibonacci and Double Period sequences. The electronic spectra were obtained by solving the Schr¨odinger equation in the tight-binding approach. Numerical results are presented for the two types of systems with different values of the parameter of nonextensivity q

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In this work we study a connection between a non-Gaussian statistics, the Kaniadakis statistics, and Complex Networks. We show that the degree distribution P(k)of a scale free-network, can be calculated using a maximization of information entropy in the context of non-gaussian statistics. As an example, a numerical analysis based on the preferential attachment growth model is discussed, as well as a numerical behavior of the Kaniadakis and Tsallis degree distribution is compared. We also analyze the diffusive epidemic process (DEP) on a regular lattice one-dimensional. The model is composed of A (healthy) and B (sick) species that independently diffusive on lattice with diffusion rates DA and DB for which the probabilistic dynamical rule A + B → 2B and B → A. This model belongs to the category of non-equilibrium systems with an absorbing state and a phase transition between active an inactive states. We investigate the critical behavior of the DEP using an auto-adaptive algorithm to find critical points: the method of automatic searching for critical points (MASCP). We compare our results with the literature and we find that the MASCP successfully finds the critical exponents 1/ѵ and 1/zѵ in all the cases DA =DB, DA DB. The simulations show that the DEP has the same critical exponents as are expected from field-theoretical arguments. Moreover, we find that, contrary to a renormalization group prediction, the system does not show a discontinuous phase transition in the regime o DA >DB.

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This dissertation briefly presents the random graphs and the main quantities calculated from them. At the same time, basic thermodynamics quantities such as energy and temperature are associated with some of their characteristics. Approaches commonly used in Statistical Mechanics are employed and rules that describe a time evolution for the graphs are proposed in order to study their ergodicity and a possible thermal equilibrium between them

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The work is to make a brief discussion of methods to estimate the parameters of the Generalized Pareto distribution (GPD). Being addressed the following techniques: Moments (moments), Maximum Likelihood (MLE), Biased Probability Weighted Moments (PWMB), Unbiased Probability Weighted Moments (PWMU), Mean Power Density Divergence (MDPD), Median (MED), Pickands (PICKANDS), Maximum Penalized Likelihood (MPLE), Maximum Goodness-of-fit (MGF) and the Maximum Entropy (POME) technique, the focus of this manuscript. By way of illustration adjustments were made for the Generalized Pareto distribution, for a sequence of earthquakes intraplacas which occurred in the city of João Câmara in the northeastern region of Brazil, which was monitored continuously for two years (1987 and 1988). It was found that the MLE and POME were the most efficient methods, giving them basically mean squared errors. Based on the threshold of 1.5 degrees was estimated the seismic risk for the city, and estimated the level of return to earthquakes of intensity 1.5°, 2.0°, 2.5°, 3.0° and the most intense earthquake never registered in the city, which occurred in November 1986 with magnitude of about 5.2º

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Over exploitation of oil deposits on land onshore or offshore, there is simultaneous generation of waste water, known as produced water, which represents the largest waste stream in the production of crude oil. The relationship between the chemical composition of oil and water production and the conditions in which this process occurs or is favored are still poorly studied. The area chosen for the study has an important oil reserve and an important aquifer saturated with freshwater meteoric. The aim of this work is to study some chemical parameters in water produced for each reservoir zone of production in mature oil fields of Açu Formation, using the hydrochemical and statistical analysis to serve as a reference and be used as tools against the indicator ranges water producers in oil producing wells. Samples were collected from different wells in 6 different areas of production and were measured 50 parameters, which can be classified into three groups: anions, cations and physicochemical properties (considering only the parameters that generated values above detection limits in all samples). Through the characterization hydrochemistry observed an area of water and chlorinated sodium, chlorinated calcium or magnesium (mixed) in well water in different areas of Açu, by applying a statistical treatment, we obtained a discriminant function that distinguishes chemically production areas. Thus, it was possible to calculate the rate of correct classification of the function was 76.3%. To validate this model the accuracy rate was 86%

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Considering a non-relativistic ideal gas, the standard foundations of kinetic theory are investigated in the context of non-gaussian statistical mechanics introduced by Kaniadakis. The new formalism is based on the generalization of the Boltzmann H-theorem and the deduction of Maxwells statistical distribution. The calculated power law distribution is parameterized through a parameter measuring the degree of non-gaussianity. In the limit = 0, the theory of gaussian Maxwell-Boltzmann distribution is recovered. Two physical applications of the non-gaussian effects have been considered. The first one, the -Doppler broadening of spectral lines from an excited gas is obtained from analytical expressions. The second one, a mathematical relationship between the entropic index and the stellar polytropic index is shown by using the thermodynamic formulation for self-gravitational systems

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In this work a study of social networks based on analysis of family names is presented. A basic approach to the mathematical formalism of graphs is developed and then main theoretical models for complex networks are presented aiming to support the analysis of surnames networks models. These, in turn, are worked so as to be drawn leading quantities, such as aggregation coefficient, minimum average path length and connectivity distribution. Based on these quantities, it can be stated that surnames networks are an example of complex network, showing important features such as preferential attachment and small-world character

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The Atlantic Forest biome occupies much of the Atlantic coast of Brazil, in addition to portions of Paraguay and Argentina. Due mainly to its biodiversity which falls in the group of global hotspots, i.e., areas that have high priority for conservation. Although currently there are some available devices that assist in their protection in the course of the history of occupation and exploitation of the Brazilian territory, this biome has gone, and is still going through, an intense process of devastation, caused mainly by the pressure from economic activities, culminating in a significant reduction of its area and consequent fragmentation of the landscape, which brings with hosts a series of problems at various scales and aspects. As in most municipalities included in the reach area of the biome, the situation of forest fragmentation in Tibau do Sul / RN is quite critical, reflecting on a truly diverse landscape with broad typology of land uses. Among the alternatives aimed at the conservation of this biome include the creation of protected areas and the creation of ecological corridors, the latter being more efficient by connecting the remaining forests, increasing landscape connectivity, providing significant gains in relation to biodiversity. However, a major problem on implementation of Ecological Corridors projects is related to the selection of areas for this purpose, in this sense Geography can provide important contributions through the integrated study of landscape in the light of the geosystemic approach and the use of Geographical Information System (GIS) in order to permit assessment of reality having as a base the integration of ecological, biological and man-made aspects. Thus, this research aims to indicate potential areas and propose scenarios delimitation of Ecological Corridors in the municipality of Tibau do Sul / RN through Geographic Inference techniques in GIS platform. Therefore, the methodology adopted is based on the Geosystemic approach. From these elements were created 4 models to indicate potential areas for implementation of Ecological Corridors from the environmental perspective (potential erosion), socioeconomic (cover and land prices), legislative (areas protected by environmental legislation) and integrated (combination of environmental factors, socioeconomic and legislative), which in turn served as a basis for proposing scenarios aimed at this purpose. The results showed that all models can be quite useful in indicating potential areas for the establishment of ecological corridors, especially when based on an integrated approach between environmental and anthropogenic. The Corridors delimitation proposes shown may perform duties beyond the establishment of connectivity between fragments, since they also may have usefulness in controlling erosion and protecting fragile environments. Among the models developed, the integrated constituted itself as the best option because it enabled the interconnection of a larger number of fragments from a better use of the potentialities present in the landscape

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A estatística exerce um papel fundamental no método científico, a qual se preocupa em organizar, descrever, analisar e interpretar os dados obtidos a partir de uma observação ou de um experimento. Todavia, ela continua sendo pouco acessível na interpretação, seja por parte do leitor ou por parte daquele que a utiliza. Às vezes, a estatística é mal aplicada ou não compreendida devido aos termos, com significado próprio. Além disso, existem poucos artigos científicos da área de Ortodontia relacionados com este assunto. Assim, o presente artigo propõe realizar um levantamento sobre as freqüências do uso da estatística, fazer considerações sobre a seleção dos seus métodos e explanar sobre as possíveis interpretações dos resultados.

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Nas últimas duas décadas, o crescimento do interesse pela metodologia Seis Sigma intensificou a aplicação da abordagem estatística e de outras abordagens quantitativas com o intuito de melhorar não apenas a qualidade de produtos, serviços e processos, como também aumentar o desempenho organizacional e o processo de tomada de decisão. Este artigo trata da aplicação da abordagem estatística no contexto da gestão da qualidade em indústrias de alimentos de médio e grande porte do Estado de São Paulo com o propósito de: identificar quais ferramentas e técnicas estatísticas são mais amplamente empregadas por indústrias do setor para garantir e controlar a qualidade; avaliar a interdependência entre o sucesso da implementação de programas de qualidade e segurança alimentar como Boas Práticas de Fabricação (BPF) e sistema de Análise de Perigos e Pontos Críticos de Controle (APPCC) e o uso de estatística; e analisar estimativas do grau de relevância do pensamento estatístico e de seus benefícios como ferramenta de melhoria da qualidade. Um survey exploratório-descritivo foi realizado e os resultados revelaram que a abordagem estatística começa a ser mais valorizada nas indústrias de alimentos pela relevância de seus benefícios assim como já ocorre em outros setores. Há evidências de que a implantação bem sucedida dos programas de segurança alimentar seja uma condição primordial para o uso efetivo de estatística e de outras abordagens quantitativas.

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As raças e populações de pupunheiras ao longo dos rios Amazonas e Solimões apresentam grande variabilidade genética ainda não totalmente caracterizada. Neste estudo, foram aplicadas técnicas estatísticas multivariadas a 15 descritores morfológicos numa tentativa de caracterizar, morfometricamente, três raças existentes ao longo da Bacia desses rios. As três análises em conjunto permitiram uma discriminação das raças, mostrando também que os descritores mais importantes nessa seleção foram: número de espigas, comprimento da ráquis, peso do fruto, espessura das cascas, facilidade para descascar os frutos, peso das cascas, sabor dos frutos, espessura da polpa, distância morfológica dos frutos e peso da semente.