Hilbert Transform
Mostrando 13-24 de 31 artigos, teses e dissertações.
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13. Identificação e caracterização de não-linearidades em dinâmica estrutural / Identification and characterization of nonlinearities in structural dynamics
Esta dissertação tem como objetivo principal realizar uma investigação sobre técnicas de identificação e caracterização de não linearidades em dinâmica estrutural. Em particular, busca-se aplicar as transformadas de Hilbert e Hilbert-Huang na identificação e caracterização de um sistema estrutural composto de uma viga metálica em balanço com
Publicado em: 2008
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14. Medição de impedância utilizando sistemas digitais
Conducting measurements is, in the most part of practical situations, essential for scientific research. It is so important, that it can be said, that all areas in engineering are dependent of it. As well known, impedance measurement is a subject of great interest in many application fields, each of which has different demands in terms of accuracy, range, me
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/06/2007
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15. Analysis of auditory brainstem response through instantaneous attributes of time-series / Análise de potenciais evocados auditivos de tronco encefálico através de atributos instantâneos de séries temporais
The extraction of signal components from Auditory Brainstem Response (ABR), referred to as Jewett waves, is an important step in studies regarding the investigation of the behavior of the auditory system. However, this evaluation is complex and depends on the experience of the specialist. In this context, the objectives of this research are to compare ABR an
Publicado em: 2007
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16. Projeto de novos sistemas-wavelet com aplicaÃÃes na anÃlise de sinais do sistema elÃtrico / Design of new wavelet systems with applications in power system signal analysis
The wavelet transform equipped with the multiresolution analysis has been offered as an efficient tool in the investigation of non stationary signals derived from a plenty of areas. The development of new âbasisâ so as to implement such techniques has the aim of enlarging the span of suitable choices for a particular purpose. This thesis introduces new fam
Publicado em: 2006
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17. Analise numerica e experimental do indice de vibro-impacto em alavancas de transmissão mecanica / Numerical and experimental vibro-impact level analysis in mechanical gearshift levers
Este trabalho apresenta a análise numérica e experimental do índice de vibro-impacto em alavancas de transmissão mecânica. Foram desenvolvidos modelos de alavanca que consideram não-linearidades na estrutura. Métodos para quantificação do vibro-impacto foram obtidos na literatura e implementados para o levantamento de curvas, as quais indicam a vari
Publicado em: 2005
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18. Detecção e caracterização de não linearidades em sistemas mecanicos
This work presents a method for the detection of non -linearities in a physically realizable system based on the Hilbert transform and the implementation of the quadratic mathematical model in the frequency domain. This model is non-parametric, based on the Volterra and Wiener series and uses the spectral and biespectral analysis to obtain the frequency resp
Publicado em: 1990
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19. Hilbert Transforms in Yukawan Potential Theory
If H denotes the classical Hilbert transform and Hu(x) = v(x), then the functions u(x) and v(x) are the values on the real axis of a pair of conjugate functions, harmonic in the upper half-plane. This note gives a generalization of the above concepts in which the Laplace equation Δu = 0 is replaced by the Yukawa equation Δu = μ2u and in which the Cauchy-R
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20. AN INEQUALITY FOR THE HILBERT TRANSFORM*
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21. Singular integrals related to the Radon transform and boundary value problems
Two classes of integral operators are introduced that combine features of Calderón—Zygmund singular integrals, the Hilbert integral, and the Radon transform. Examples and applications arising from integral geometry and several complex variables are discussed.
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22. On Calderón’s conjecture for the bilinear Hilbert transform
We show that the bilinear Hilbert transform defined by \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}\boldsymbol{{\mathit{Hfg}}}(\boldsymbol{{\mathit{x}}})\boldsymbol{{\mathrm{\
The National Academy of Sciences.
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23. Lp estimates for the bilinear Hilbert transform
For the bilinear Hilbert transform given by: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathit{H\hspace{.167em}fg}}({\mathit{x}}){\mathrm{\hspace{.167em}=\hspace{.167em}p.v
The National Academy of Sciences of the USA.
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24. Engineering analysis of biological variables: An example of blood pressure over 1 day
Almost all variables in biology are nonstationarily stochastic. For these variables, the conventional tools leave us a feeling that some valuable information is thrown away and that a complex phenomenon is presented imprecisely. Here, we apply recent advances initially made in the study of ocean waves to study the blood pressure waves in the lung. We note fi
The National Academy of Sciences.