Approximation Algorithm
Mostrando 1-12 de 74 artigos, teses e dissertações.
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1. Modeling and FPGA-based implementation of an efficient and simple envelope detector using a Hilbert Transform FIR filter for ultrasound imaging applications
Abstract Introduction Although the envelope detection is a widely used method in medical ultrasound (US) imaging to demodulate the amplitude of the received echo signal before any back-end processing, novel hardware-based approaches have been proposed for reducing its computational cost and complexity. In this paper, we present the modeling and FPGA impleme
Res. Biomed. Eng.. Publicado em: 15/01/2018
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2. Influences of the signal border extension in the discrete wavelet transform in EEG spike detection
Abstract Introduction The discrete wavelet transform is used in many studies as signal preprocessor for EEG spike detection. An inherent process of this mathematical tool is the recursive wavelet convolution over the signal that is decomposed into detail and approximation coefficients. To perform these convolutions, firstly it is necessary to extend signal
Res. Biomed. Eng.. Publicado em: 12/09/2016
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3. Active vibration control of an arbitrary thick piezolaminated beam with imperfectly integrated sensor and actuator layers
A spatial state-space formulation based on the linear twodimensional piezoelasticity theory and involving local/global transfer matrices is applied to investigate the active vibration suppression of a simply supported, arbitrarily thick, orthotropic elastic beam, imperfectly integrated with spatially distributed piezoelectric actuator and sensor layers on it
Lat. Am. j. solids struct.. Publicado em: 2014
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4. Finite volume simulation of 2-D steady square lid driven cavity flow at high reynolds numbers
In this work, computer simulation results of steady incompressible flow in a 2-D square lid-driven cavity up to Reynolds number (Re) 65000 are presented and compared with those of earlier studies. The governing flow equations are solved by using the finite volume approach. Quadratic upstream interpolation for convective kinematics (QUICK) is used for the app
Braz. J. Chem. Eng.. Publicado em: 2013-12
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5. A non-standard optimal control problem arising in an economics application
A recent optimal control problem in the area of economics has mathematical properties that do not fall into the standard optimal control problem formulation. In our problem the state value at the final time the state, y(T) = z, is free and unknown, and additionally the Lagrangian integrand in the functional is a piecewise constant function of the unknown val
Pesqui. Oper.. Publicado em: 2013-04
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6. An improved version of Inverse Distance Weighting metamodel assisted Harmony Search algorithm for truss design optimization
This paper focuses on a metamodel-based design optimization algorithm. The intention is to improve its computational cost and convergence rate. Metamodel-based optimization method introduced here, provides the necessary means to reduce the computational cost and convergence rate of the optimization through a surrogate. This algorithm is a combination of a hi
Lat. Am. j. solids struct.. Publicado em: 2013-03
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7. Codificação de vídeo baseada em fractais e representações esparsas / Video coding based on fractals and sparse representations
A video is a sequence of still images representing scenes in motion. A video is a sequence of extremely similar images separated by abrupt changes in their content. If these images were transmitted and stored without any kind of preprocessing, this would require a massive amount of storage space and communication channels with very high bandwidths. Lossy com
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/03/2012
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8. Aproximação de métricas finitas por métricas arbóreas e aplicações / Approximation of finite metrics by tree metrics and applications
Many optimization problems on graphs, especially metric problems, are easier to solve on trees. Therefore, a strategy for obtaining a good algorithm for certain problems is to obtain a tree that approximates the graph, and use a solution of the problem on the tree as an approximate solution for the problem on the original graph. We study the work of Fakcharo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/12/2011
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9. Recoloração convexa de caminhos / Convex recoloring of paths
O foco central desta tese é o desenvolvimento de algoritmos para o problema de recoloração convexa de caminhos. Neste problema, é dado um caminho cujos vértices estão coloridos arbitrariamente, e o objetivo é recolorir o menor número possível de vértices de modo a obter uma coloração convexa. Dizemos que uma coloração de um grafo é convexa se,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/11/2011
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10. Operational Tau approximation for a general class of fractional integro-differential equations
In this work, an extension of the algebraic formulation of the operational Tau method (OTM) for the numerical solution of the linear and nonlinear fractional integro-differential equations (FIDEs) is proposed. The main idea behind the OTM is to convert the fractional differential and integral parts of the desired FIDE to some operational matrices. Then the F
Computational & Applied Mathematics. Publicado em: 2011
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11. A structure-preserving iteration method of model updating based on matrix approximation theory
Some theories and a method are discussed on updating a generalized centrosymmetric model. It gives a generalized centrosymmetric modified solution with partial prescribed least square spectra constraints. The emphasis is given on exploiting structure-preserving algorithm based on matrix approximation theory. A perturbation theory for the modified solution is
Computational & Applied Mathematics. Publicado em: 2010-06
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12. STOCHASTIC DYNAMIC PROGRAMMING AND CONVEX HULL ALGORITHM IN THE HYDROTHERMAL SYSTEMS OPERATION PLANNING / PROGRAMAÇÃO DINÂMICA ESTOCÁSTICA E ALGORITMO DE FECHOS CONVEXOS NO PLANEJAMENTO DA OPERAÇÃO DE SISTEMAS HIDROTÉRMICOS
This thesis presents a new approach for the expected-cost-to-go functions modeling used in the stochastic dynamic programming (SDP) algorithm. The proposed technique is applied to the long-term operation planning of electrical power systems. Using state space discretization, the convex hull algorithm is used for constructing a series of hyperplanes that comp
Publicado em: 2010