Wavelet Analysis
Mostrando 13-24 de 167 artigos, teses e dissertações.
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13. Respiratory syncytial virus seasonality in Brazil: implications for the immunisation policy for at-risk populations
Respiratory syncytial virus (RSV) infection is the leading cause of hospitalisation for respiratory diseases among children under 5 years old. The aim of this study was to analyse RSV seasonality in the five distinct regions of Brazil using time series analysis (wavelet and Fourier series) of the following indicators: monthly positivity of the immunofluoresc
Mem. Inst. Oswaldo Cruz. Publicado em: 29/03/2016
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14. Online hybrid modeling method with application for predicting Bauxite production indicators
Abstract In the bauxite flotation process, concentrate grade and tailings grade are key production indicators; however, they are difficult to measure online. It is also difficult to develop an effective mathematical model for the process because of the complex non-linear and uncertain relationship among the feed parameters (feed grade, pulp density, slurry p
Rem: Rev. Esc. Minas. Publicado em: 2015-12
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15. Multiscale Analysis of GPS Time Series from Non-decimated Wavelet to Investigate the Effects of Ionospheric Scintillation
Devido às inúmeras possibilidades de aplicação, a teoria de wavelets tem sido utilizada nas mais diversas áreas de pesquisa. A Transformada Wavelet Discreta é a versão mais conhecida. Porém, o processo de decimação necessário para seu cálculo, faz com que ela seja sensível à origem, o que para algumas aplicações não é o ideal, principalment
TEMA (São Carlos). Publicado em: 2015-08
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16. Optimum dynamic analysis of 2D frames using free-scaled wavelet functions
This paper presents a wavelet-based scheme for dynamic analysis of 2-dimensional (2D) frames. In the proposed approach, free-scaled wavelet functions are developed for Multi-Degrees-of-Freedom (MDOF) structures, particularly, complex Chebyshev and simple Haar wavelets are implemented. A simple step-by-step and explicit algorithm is presented to calculate the
Lat. Am. j. solids struct.. Publicado em: 2014-11
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17. Damage identification from uniform load surface using continuous and stationary wavelet transforms
Derived from flexibility matrix, Uniform Load Surface (ULS) is used to identify damages in beam-type structures. This method is beneficial in terms of more participating the lower order modes and having less prone to noise and irregularities in the measured data in comparison with the original flexibility matrix technique. Therefore, these characteristics ma
Lat. Am. j. solids struct.. Publicado em: 2014-10
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18. Cutting force response in milling of Inconel: analysis by wavelet and Hilbert-Huang Transforms
We study the milling process of Inconel. By continuously increasing the cutting depth we follow the system response and appearance of oscillations of larger amplitude. The cutting force amplitude and frequency analysis has been done by means of wavelets and Hilbert-Huang transform. We report that in our system the force oscillations are closely related to th
Lat. Am. j. solids struct.. Publicado em: 2013-01
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19. Algoritmo híbrido e inteligente para o diagnóstico das condições operativas de transformadores de potência no contexto da qualidade da energia elétrica / Hybrid intelligent algorithm for the diagnosis of operating conditions of power transformers in the context of power quality
This research aimed to develop an algorithm able to diagnose the operating conditions of power transformers. The variables considered to classify the presented conditions were the normally used by differential protection logic, i.e., the differential current and the harmonic content in the signals in analysis. Moreover, the relationship between some phenomen
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/07/2012
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20. Desenvolvimento de ferramenta de comparação de técnicas de processamento de sinais para determinar fadiga muscular por meio do sinal emg / Toolkit development for signals processing technics comparison to detect muscular fadigue by EMG signal
This study aimed to development of a computational tool for electromyographic signal (EMG) analysis by signal processing techniques to determine muscular fatigue. With Ethics Committee of Federal University of Goiás approve were recorded from the dominant biceps brachii of 10 volunteers, that did not ever had muscular disease. The protocol consisted on get
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/07/2012
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21. Análise de eventos em redes de distribuição por meio das transformadas Wavelet e S / Event analysis in distribution networks using Wavelet and S transform
O presente trabalho apresenta uma comparação de duas técnicas para a análise tempo - frequência em análise de qualidade de energia elétrica para sinais de tensão que contenham distúrbios individuais ou simultâneos. Dessa forma, o objetivo, desta dissertação, é encontrar uma ferramenta que forneça as características e parâmetros para a localiz
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/04/2012
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22. Inertial Measurement Unit Calibration Procedure for a Redundant Tetrahedral Gyro Configuration with Wavelet Denoising
Abstract: The aim of this paper was to present a calibration procedure applied to an inertial measurement unit composed of a triad of accelerometers and four gyros in a tetrad configuration. The procedure has taken into account a technique based on least-square methods and wavelet denoising to perform the best estimate of the sensor axis misalignments. The w
J. Aerosp. Technol. Manag.. Publicado em: 2012-06
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23. Processamento de sinais de descargas parciais em tempo real com base em wavelets e seleção de coeficientes adaptativa espacialmente
On-line partial discharge (PD) analysis is a highly pursued feature due to the economy related to scheduled shutdowns, disassembling and transport. Nevertheless, on-site PD measurements are frequently limited by interferences found in high-voltage facilities, a situation that imposes the continued development of PD signal processing methods. In the last year
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/11/2011
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24. Detecção e isolação de falhas em unidades de medidas inerciais com redundância mínima de giros de fibra óptica / Fault detection and isolation on inertial measurement units with minimal redundancy of fiber optic gyros
Nesta tese são apresentados os estudos inerentes ao processo de detecção e isolação de falhas (DIF) em unidades de medidas inerciais (UMI) com redundância mínima de girômetros de fibra óptica. Nesses estudos, como elementos acessórios ao atendimento do objetivo principal, foram abordados os modelos para construção e calibração da UMI, além das
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/11/2011