نتایج جستجو برای: wavelet analyses

تعداد نتایج: 422507  

Alireza Sadremomtaz, Ebrahim Siri

Wavelet transformation is one of the most practical mathematical transformations in the field of image processing, especially image and signal processing. Depending on the nature of the multiresolution analysis, Wavelet transformation become more accessible and powerful tools. In this paper, we refer to the mathematical foundations of this transformation.   Introduction: The...

Golestanian, Heidari, Homaei,

A new method based on principal component analysis (PCA) and artificial neural networks (ANN) is proposed for fault diagnosis of gearboxes. Firstly the six different base wavelets are considered, in which three are from real valued and other three from complex valued. Two wavelet selection criteria Maximum Energy to Shannon Entropy ratio and Maximum Relative Wavelet Energy are used and compared...

2016
Dongqing Wang Xu Zhang Xiaoping Gao Xiang Chen Ping Zhou

This study presents wavelet packet feature assessment of neural control information in paretic upper limb muscles of stroke survivors for myoelectric pattern recognition, taking advantage of high-resolution time-frequency representations of surface electromyogram (EMG) signals. On this basis, a novel channel selection method was developed by combining the Fisher's class separability index and t...

2012
Hsueh-Hsien Chang

Energy management systems strive to use energy resources efficiently, save energy, and reduce carbon output. This study proposes transient feature analyses of the transient response time and transient energy on the power signatures of non-intrusive demand monitoring and load identification to detect the power demand and load operation. This study uses the wavelet transform (WT) of the time-freq...

Journal: :Journal of Mathematical Sciences 2023

Periodic multiresolution analyses in the space of periodic complex-valued functions an integer argument are studied. A characterization terms Fourier coefficients forming a scaling sequence is obtained. An example analysis with that consists trigonometric polynomials minimal possible spectrum presented. wavelet system associated such

Journal: :رادار 0
سید امیر حمدی حبیب اله دانیالی محمد صادق هل فروش مرضیه زارع

in this paper, a block-based method in wavelet domain for sar image coding is presented based on the ezbc algorithm. to better preserve edges and textural structure in sar images, instead of using traditional dyadic wavelet transform, a packet wavelet is employed. to improve the efficiency of the ezbc algorithm for sar image coding, a modified version of this algorithm, is proposed. this modifi...

2004
Tomasz Tarasiuk Mariusz Szweda

This paper has been focused on the problem of analysis of notching occurring in electric power systems. Especially a choice of appropriate sampling frequency and its consequence for results of the analysis have been considered. Moreover, the problem of wavelet filter length and, in some respect, wavelet family has been analyzed as well. All analyses have been based on the real voltage samples, ...

Journal: :Risks 2023

Wavelet power spectrum (WPS) and wavelet coherence analyses (WCA) are used to examine the co-movements among oil prices, green bonds, CO2 emissions on daily data from January 2014 October 2022. The WPS results show that returns exhibit significant volatility at low medium frequencies, particularly in 2014, 2019–2020, Also, Green Bond Index presents end of 2019–2020 beginning 2022 low, medium, h...

Journal: :wavelets and linear algebra 0
arash ghaani farashahi university of vienna

this article presents an analytic approach to study admissibility conditions related to classical full wavelet systems over finite fields using tools from computational harmonic analysis and theoretical linear algebra. it is shown that for a large class of non-zero window signals (wavelets), the generated classical full wavelet systems constitute a frame whose canonical dual are classical full ...

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