Approximations Methods
Mostrando 1-12 de 52 artigos, teses e dissertações.
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1. Pesquisas em políticas de comunicação em contextos de crise
By way of Density Functional Theory (DFT)-based computational methods with commercially available software, the computational work of which about the molecular properties, the vibrational modes and vibrational frequencies of finasteride were accomplished for the first time. In order to gain a deeper and more thorough understanding of the molecular structure
Intercom, Rev. Bras. Ciênc. Comun.. Publicado em: 2020-05
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2. VIBRATIONAL SPECTROSCOPIC INVESTIGATION AND MOLECULAR STRUCTURE OF A 5α-REDUCTASE INHIBITOR: FINASTERIDE
By way of Density Functional Theory (DFT)-based computational methods with commercially available software, the computational work of which about the molecular properties, the vibrational modes and vibrational frequencies of finasteride were accomplished for the first time. In order to gain a deeper and more thorough understanding of the molecular structure
Quím. Nova. Publicado em: 2020-05
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3. Fatores de emissão de compostos carbonílicos medidos em um túnel do Rio de Janeiro, Brasil, em condições reais de dirigibilidade
Real-world vehicle emissions of carbonyls compounds (CC) were determined at the Rebouças Tunnel, Rio de Janeiro (Brazil). The tunnel is a two-bore tunnel with three lanes in each direction and has a length of 2840 m, divided in two sections. On average, approximately 5,000 vehicles (95% light duty) were passing the tunnel per hour. Sixteen samples were simu
Quím. Nova. Publicado em: 2020-04
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4. A special class of continuous general linear methods
We consider the construction of a class of numerical methods based on the general matrix inverse [14] which provides continuous interpolant for dense approximations (output). Their stability properties are similar to those for Runge-Kutta methods. These methods provide a unifying scope for many families of traditional methods. They are self-starting, to chan
Comput. Appl. Math.. Publicado em: 2012
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5. Indicadores de erros a posteriori na aproximação de funcionais de soluções de problemas elípticos no contexto do método Galerkin descontínuo hp-adaptivo / A posteriori error indicators in the approximation of functionals of elliptic problems solutions in the context of hp-adaptive discontinuous Galerkin method
In this work we study goal-oriented a posteriori error indicators for approximations by the discontinuous Galerkin method for the biharmonic and Poisson equations. The methodology used for the indicators is based on the dual problem associated with the functional, which is known to generate the most effective indicators. The two main error indicators based o
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/09/2011
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6. Comportamento crítico da produção de entropia em modelos com dinâmicas estocásticas competitivas / Critical behavior of entropy production in models with competitive stochastic dynamics
We study kinetic phase transitions and the critical behavior of the entropy production in spin models with nearest neighbor interactions subject to two Glauber dynamics, which simulate two thermal baths at different temperatures. In this way, it is assumed that the system corresponds to a continuous time Markov process which obeys the master equation. Thus,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/04/2011
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7. A family of uniformly accurate order Lobatto-Runge-Kutta collocation methods
We consider the construction of an interpolant for use with Lobatto-Runge-Kutta collocation methods. The main aim is to derive single symmetric continuous solution(interpolant) for uniform accuracy at the step points as well as at the off-step points whose uniform order six everywhere in the interval of consideration. We evaluate the continuous scheme at dif
Computational & Applied Mathematics. Publicado em: 2011
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8. Some derivative free quadratic and cubic convergence iterative formulas for solving nonlinear equations
Finding the zeros of a nonlinear equation ƒ (x) = 0, is a classical problem which has nice applications in various branches of science and engineering. In this paper, we introduce four iterative methods which is based on the central-difference and forward-difference approximations to derivatives. It is proved that three of the four methods have cubic conver
Computational & Applied Mathematics. Publicado em: 2010
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9. Picard and Adomian methods for quadratic integral equation
We are concerning with two analytical methods; the classical method of successive approximations (Picard method) [14] which consists the construction of a sequence of functions such that the limit of this sequence of functions in the sense of uniform convergence is the solution of a quadratic integral equation, and Adomian method which gives the solution as
Computational & Applied Mathematics. Publicado em: 2010
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10. The generalized attenuated Radon tranform : analytic inversion, approximations, iterative methods and applications on fluorescence tomography / A transformada generalizada atenuada de Radon : inversão, analitica, aproximações, metodos iterativos e aplicações em tomografia por fluorescencia
A Tomografia por Fluorescência de Raios X é uma nova técnica que combina a tomografia por transmissão de Raios X e a tomografia por emissão. Uma amostra de tecido (ou corpo) é bombardeada por Raios X de alta intensidade (gerados por um síncrotron) e, metais ou outros elementos a serem estudados, emitem fluorescência para uma faixa de energia típica
Publicado em: 2010
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11. Combinação de modelos de campos aleatórios markovianos para classificação contextual de imagens multiespectrais / Combining markov random field models for multispectral image contextual classification
This work presents a novel MAP-MRF approach for multispectral image contextual classification by combining higher-order Markov Random Field models. The statistical modeling follows the Bayesian paradigm, with the definition of a multispectral Gaussian Markov Random Field model for the observations and a Potts MRF model to represent the a priori knowledge. In
Publicado em: 2010
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12. Um estudo sobre métodos de Kernel para classificação e agrupamento de dados
The learning machines project involves modelling a set of samples based on the mapping performance of the input-output pairs. The group of samples submitted to training provides information for determining the parameters of the model. And the validation and/or test group evaluates the performance of the classifier on its generalization ability. However, the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/08/2009