Adaptive Filter
Mostrando 13-24 de 61 artigos, teses e dissertações.
-
13. ROBUST VARIABLE STRUCTURE MODEL REFERENCE ADAPTIVE CONTROL APPLIED TO ACTIVE POWER FILTERS / CONTROLE ADAPTATIVO ROBUSTO DE ESTRUTURA VARIÁVEL POR MODELO DE REFERÊNCIA APLICADO A FILTROS ATIVOS DE POTÊNCIA
This works presents a Robust Variable Structure Model Reference Adaptive Control scheme denoted VSRMRAC. In this adaptive control strategy, each parameter of the control law is obtained by the sum of two other adaptive terms. One of them is associated with the RMRAC algorithm, while the other is composed of an adaptive gain rated by an approximated sign func
Publicado em: 2010
-
14. Novas propostas em filtragem de projeções tomográficas sob ruído Poisson
In this dissertation we present techniques for filtering of tomographic projections with Poisson noise. For the filtering of the tomogram projections we use variations of three filtering techniques: Bayesian estimation, Wiener filtering and thresholding in Wavelet domain. We used ten MAP estimators, each estimator with a diferent probability density as prior
Publicado em: 2010
-
15. Filtro de partículas adaptativo para o tratamento de oclusões no rastreamento de objetos em vídeos / Adaptive MCMC-particle filter to handle of occlusions in object tracking on videos
O rastreamento de objetos em vídeos representa um importante problema na área de processamento de imagens, quer seja pelo grande número de aplicações envolvidas, ou pelo grau de complexidade que pode ser apresentado. Como exemplo de aplicações, podemos citar sua utilização em áreas como robótica móvel, interface homem-máquina, medicina, automaç
Publicado em: 2010
-
16. Técnica de controle adaptativo robusto aplicada a filtros ativos de potência e paralelo
Os métodos para compensação de correntes e tensões harmônicas vêm sendo bastante utilizados, visto que esses métodos permitem reduzir a níveis aceitáveis as distorções harmônicas nas tensões ou correntes em um sistema elétrico de potência, e ainda, compensar reativos. A redução de harmônicas e reativos contribuem para: a diminuição das pe
Publicado em: 2010
-
17. Processing, radiometric correction, autofocus and polarimetric classification of circular SAR data.
The demand for high resolution SAR systems and also for imaging techniques to retrieve scene information on the third dimension have stimulated the development of new acquisition modes and processing approaches. This work studies one of the newest SAR acquisition modes being used, namely the Circular SAR, in which the platform follows a non-linear circular t
Publicado em: 2010
-
18. Combinação afim de algoritmos adaptativos. / Affine combination of adaptive algorithms.
In order to improve the performance of adaptive filters, the combination of algorithms is receiving much attention in the literature. This method combines linearly the outputs of two filters operating in parallel with different step-sizes to obtain an adaptive filter with fast convergence and reduced excess mean squared error (EMSE). In this context, it was
Publicado em: 2009
-
19. Análise da transformada wavelet direcional adaptativa na codificação de imagens
This work presents a method for the numerical stability analysis of adaptive lifting-based directional transforms. The goal is to investigate the relation between the directions set in the lifting scheme and the reconstruction quality of the corresponding bases. This new method is based on the variation in frequency of the condition number of the synthesis p
Publicado em: 2009
-
20. Sobre a velocidade de convergência da filtragem adaptativa IIR. / On the convergence speed of IIR adaptive filtering.
Adaptive filters with infinite impulse response (IIR) can replace with advantages the ones with finite impulse response (FIR). One of these advantages is the reduced number of parameters which leads to a smaller computational complexity giving similar responses. However, the use of adaptive IIR filters has some pratical issue, being the most prominent its sl
Publicado em: 2008
-
21. Circuitos Multiplicadores Array de Baixo Consumo de Potência Aplicados a Filtros Adaptativos / Low-Power Array Multipliers Circuits for Adaptive Filter
O objetivo principal deste trabalho é a implementação e análise de novas arquiteturas de circuitos multiplicadores array digitais recentemente apresentados no meio cientifico com diferentes técnicas de redução de potência, tais como a utilização de eficientes estruturas de circuitos somadores, bem como a otimização dos blocos dedicados de multipl
Publicado em: 2008
-
22. Frequency estimation in power system through adaptive filtering / Estimação da freqüência em sistemas elétricos de potência através de filtragem adaptativa
This work presents a method for frequency estimation in power systems using adaptive filters based in the algorithm of least mean square (LMS). The analysis of the power system is made through the conversion of the three-phase voltages in a complex signal with the application of alfabetatransform, whose complex form was directed to the algorithm of adaptive
Publicado em: 2007
-
23. Análise e Síntese de um Algoritmo Phase-Locked-Loop Robusto para Estimação de Amplitude, Fase e Freqüência de Sinais Elétricos
The always more restrictive energy quality benchmarks, pushed on by consumers, associated with the electric sector deregulamentation has been imposing the necessity, for the concessionaries, of a better and decentralized monitoring of energy electric quality. At the same time, the increase of nonlinear loads connected to the electric network, among other fac
Publicado em: 2007
-
24. Modal parameter identification of structures and rotating machine by adaptative filter / Identificação de parametros modais de estruturas e maquinas rotativas atraves da filtragem adaptativa
This work investigates the use of adaptive filters for parameter identification. Although adaptive algorithms are still rarely utilized in the mechanical engineering field, the recursive least square and recursive least square with QR decomposition methods can be implemented based on the second ordinary differential equations in order to characterize the mod
Publicado em: 2007