Least Squares Problem
Mostrando 13-24 de 48 artigos, teses e dissertações.
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13. Filtros de Kalman robustos para sistemas dinâmicos singulares em tempo discreto / Robust Kalman filters for discrete-time singular systems
This thesis considers the optimal robust estimates problem for discrete-time singular dymanic systems. New recursive algorithms are developed for the Kalman filtered and predicted estimated recursions with the corresponding Riccati equations. The singular robust Kalman type filter and the corresponding recursive Riccati equation arer obtained in their most g
Publicado em: 2009
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14. Aplicação de metodos quimiometricos de calibração de segunda ordem e transferencia de calibração na determinação simultanea de misturas de farmacos utilizando espectroscopia de fluorescencia molecular em fase solida / Aplication of chemometric methods of second order calibration and transfer of calibration for simultaneous determination of pharmaceutical mixture using solid-phase molecular fluorescence
In this work it was developed a methodology for determination of acetylsalicylic acid (ASA), paracetamol and caffeine in pharmaceutical formulations using solidphase molecular fluorescence and second order calibration methods. This methodology is usefull even in the presence of unknown interferences and with spectral overlap of the components in the mixture.
Publicado em: 2009
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15. A software for parameter estimation in dynamic models
A common problem in dynamic systems is to determine parameters in an equation used to represent experimental data. The goal is to determine the values of model parameters that provide the best fit to measured data, generally based on some type of least squares or maximum likelihood criterion. In the most general case, this requires the solution of a nonlinea
Brazilian Journal of Chemical Engineering. Publicado em: 2008-12
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16. Accelerating the Levenberg-Marquardt method for the minimization of the square of functions with box constraints / Acelerando o metodo de Levenberg-Marquardt para a minimização da soma de quadrados de funções com restrições de caixa
In this work, we present an active set algorithm for minimizing the sum of squares of smooth functions, with box constraints. The algorithm is highly inspired in the work of Birgin and Mart´inez [4]. The differences are concentrated on the chosen search direction and on the use of an acceleration technique to update the step. At each iteration, we define an
Publicado em: 2008
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17. Simulação de espectros de ressonância paramagnética eletrônica (RPE) através do programa NLSL
EPR users often face the problem of extracting information from frequently low-resolution and complex EPR spectra. Simulation programs that provide a series of parameters, characteristic of the investigated system, have been used to achieve this goal. This work describes the general aspects of one of those programs, the NLSL program, used to fit EPR spectra
Química Nova. Publicado em: 2007-10
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18. RECONSTRUÇÃO DE GEOMETRIA A PARTIR DA CONECTIVIDADE DA MALHA E DE PONTOS DE CONTROLE / RECONSTRUTION OF GEOMETRY BASED IN CONNECTIVITY AND MESH SAMPLES
This work aims at reconstructing the geometry of a mesh from its connectivity and a small set of control points, whose geometry is known.The problem is formulated as a maximization of the surface smoothness restricting the position of the control points. With this formulation, the method reduces to solving a sparse linear system using least squares minimizat
Publicado em: 2007
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19. Otimização de formulações de fluidos para freios do tipo ABNT 3 (DOT3). / Optimization of brake fluids formulations type ABNT 3 (DOT 3).
The aim of this work is to obtain optimal formulations of brake fluids ABNT 3 type while satisfying technical and market specifications, by utilizing modelling and optimization techniques of five physical and chemical properties. A methodology for the design of commercial products, based on the usage of the information available in databases where previous t
Publicado em: 2007
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20. Rede perceptron com camadas paralelas (PLP - Parallel Layer Perceptron)
This work presents a novel approach to deal with the structural risk minimization (SRM) applied to a general machine learning problem. The formulation is based on the fundamental concept that supervised learning is a bi-objective optimization problem in which two conflicting objectives should be minimized. The objectives are related to the training error, em
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/12/2006
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21. Low-sum order value optimization / Otimização da menor soma de valores ordenados
Given r real functions Fl(X),..., Fr(x) defined in n c IRn and an integer p between 1 and r, the Low Order-Value Optimization problem (LOVO) consists of minimizing the sum of the functions that take the p smallest values. If (Yl,..., Yr) is a vector of data and T(x, ti) is the predicted value of the i-th observation ith the parameters x E n, it is natural to
Publicado em: 2006
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22. Generalized approximating splitting iterations for solving linear least squares problems in finite dimensions
In this paper, a new special class of splitting iterations for solving linear least squares problems in finite dimensions is defined and their main properties of strong global convergence to any problem solution are derived. The investigation results prove the new splitting iterations to be a generalization of the approximating splitting iterations for solvi
Computational & Applied Mathematics. Publicado em: 2005-08
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23. Tecnicas autodidatas e soluções de baixa complexidade para equalização e estimação turbo
This work concerns the use of iterative receivers, which jointly perform equalization, decoding and channel estimation, to mitigate the impairments introduced by the transmission medium into the transmitted signal. First, we make a comparative study of exponential-and reduced-complexity turbo equalizers and establish the advantages and the limitations of eac
Publicado em: 2005
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24. USO DE MODELOS MULTIVARIADOS PARA A AVALIAÇÃO DO VALOR DE DIENOS EM AMOSTRAS DE GASOLINA DE PIRÓLISE / CHEMOMETRIC APPROACH TO ASSESS THE DIENE VALUE IN PYROLYSIS GASOLINE
The quality of gasoline may be affected by the presence of several compounds. Among them, the conjugated dienes play an important role due to the fact that their presence is strongly associated with gum formation, which may clogs the injector of automobiles and may causes damages in the petroleum derivates. The main used method for the determination of total
Publicado em: 2005