نتایج جستجو برای: Wavelet method

تعداد نتایج: 1655546  

Journal: :JDIM 2013
Jian Ni Yuduo Li

In order to improve the rate of facial expression recognition. The Gabor wavelet fusion PCA+FLD method is proposed as a new method this paper. Firstly, face image preprocessing, and then carries on the two-dimensional wavelet transform Gabor, first constructed five scale eight directional wavelet filter, through the PCA+FLD method for dimensionality reduction, and finally obtaining an optimum e...

Journal: :international journal of advanced biological and biomedical research 2014
abazar solgi feridon radmanesh heidar zarei vahid nourani

awareness of the level of river flow and its fluctuations at different times is one of the significant factor to achieve sustainable development for water resource issues. therefore, the present study two hybrid models, wavelet- adaptive neural fuzzy interference system (wanfis) and wavelet- artificial neural network (wann) are used for flow prediction of gamasyab river (nahavand, hamedan, iran...

2012
Rahim Kamran Mehdi Nasri Hossein Nezamabadi-pour Saeid Saryazdi

Denoising of images corrupted by Gaussian noise using wavelet transform is of great concern in the past two decades. In wavelet denoising method, detail wavelet coefficients of noisy image are thresholded using a specific thresholding function by comparing to a specific threshold value, and then applying inverse wavelet transform, results in denoised image. Recently, an effective image denoisin...

Journal: :iranian journal of science and technology transactions of electrical engineering 2015
h. nasiri soloklo r. hajmohammadi m. m. farsangi

in this paper, a new method is investigated for model order reduction of high order systems based on moment matching technique. in this method, at first, full order model is expanded by legendre wavelet function which is included in orthogonal functions. a suitable fixed structure model is considered as reduced order model whose parameters are unknown. these unknown parameters are determined us...

Journal: :Entropy 2015
Qiaoning Yang Jianlin Wang

In actual application, sensors are prone to failure because of harsh environments, battery drain, and sensor aging. Sensor fault location is an important step for follow-up sensor fault detection. In this paper, two new multi-level wavelet Shannon entropies (multi-level wavelet time Shannon entropy and multi-level wavelet time-energy Shannon entropy) are defined. They take full advantage of sen...

Journal: :iranian journal of medical physics 0
farshid babapour mofrad ph.d., candidate, faculty of engineering, science and research branch, islamic azad university, tehran, iran ali abbaspour tehrani-fard assistant professor, faculty of engineering, science and research branch, islamic azad university, tehran, iran babak ebrahimi m.sc., faculty of engineering, science and research branch, islamic azad university, tehran, iran dariush sardari assistant professor, faculty of engineering, science and research branch, islamic azad university, tehran, iran

introduction: spect is a diagnostic imaging technique the main disadvantage of which is the existence of poisson noise. so far, different methods have been used by scientists to improve spect images. the wavelet transform is a new method for de-noising which is widely used for noise reduction and quality enhancement of images. the purpose of this paper is evaluation of noise reduction in spect ...

Journal: :Journal of WSCG 2005
Michel A. Westenberg Thomas Ertl

Noise reduction is an important preprocessing step for many visualization techniques that make use of feature extraction. We propose a method for denoising 2-D vector fields that are corrupted by additive noise. The method is based on the vector wavelet transform, which transforms a vector input signal to wavelet coefficients that are also vectors. We introduce modifications to scalar wavelet c...

2005
MOHAMMAD S. NADERI B. T. PHUNG MEHDI S. NADERI

In this paper a method for extracting Partial Discharge (PD) signals is introduced, which is implemented for evaluating electrical measured partial discharges on a 66 kV / 25 MVA fully interleaved winding of a power transformer. Applying wavelet transform to a signal produces a wavelet detail coefficient distribution throughout the time-scale, which depends on the mother wavelet chosen. This me...

2011
Yinlei Tian Qingjiang Chen

In this work, a sort of binary wavelet packages with multi-scale are introduced, which are generalizations of multivariant wavelet packages. Finitely Supported wavelet bases for Sobolev spaces is researched. Steming from a pair of finitely supported refinale functions with multi-scaled dilation factor in space 2 2 ( ) L R satsfying a very mild condition, we provide a novel method for designing ...

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