نتایج جستجو برای: wavelet transform and s

تعداد نتایج: 16932503  

2017
Dongbao Guo Wei Zhang

This paper study the application of wavelet transform and fractal theory in image coding. The image coding based on wavelet transform has been studied firstly, Then, the paper make a research of fractal theory counterpart. After that, this paper research the hybrid compression coding based on wavelet transform and fractal theory, also make simulation experiment of three image coding ways mentio...

1997
Rob Zuidwijk

Combined use of the X-ray (Radon) transform and the wavelet transform has proved to be useful in application areas such as diagnostic medicine and seismology. In the present paper, the wavelet X-ray transform is introduced. This transform performs one-dimensional wavelet transforms along lines in R n , which are param-eterized in the same fashion as for the X-ray transform. It is shown that the...

Journal: :فیزیک زمین و فضا 0
احسان ذبیحی نائینی حمیدرضا سیاهکوهی

spectral decomposition is a powerful tool for analysis of seismic data. fourier transform determines the frequency contents of a signal. but for analysis of non-stationary signals, 1-d transform to frequency domain is not sufficient. in early years, transforming of seismic traces into time and frequency domain was done via windowed fourier transform, called a short time fourier transform (stft)...

Speech constitutes much of the communicated information; most other perceived audio signals do not carry nearly as much information. Indeed, much of the non-speech signals maybe classified as ‘noise’ in human communication. The process of separating conversational speech and noise is termed voice activity detection (VAD). This paper describes a new approach to VAD which is based on the Wavelet ...

کرمی, علی, کیانی , آزاده, زنج, بهمن, پور آهنگریان, فرشته ,

In this paper, Automatic electrocardiogram (ECG) arrhythmias classification is essential to timely diagnosis of dangerous electromechanical behaviors and conditions of the heart. In this paper, a new method for ECG arrhythmias classification using wavelet transform (WT) and neural networks (NN) is proposed. Here, we have used a discrete wavelet transform (DWT) for processing ECG recordings, and...

2013
Christopher H. Baker Donald A. Jordan Pamela M. Norris

The continuous wavelet transform is employed to analyze the dynamics and time-dependent energy distribution of phonon wave-packet propagation and scattering in molecular dynamics simulations. The equations of the one-dimensional continuous wavelet transform are presented and then discretized for implementation. Practical aspects and limitations of the transform are discussed, with attention to ...

2014
Jun Ma Ya-Jing Wu

In a complete Chaotic radar ranging system, its effective range is often limited by the randomness of the chaotic signal itself and other transmission channel noises or interferences. In order to improve the precision and accuracy of radar ranging system, wavelet transform is proposed to remove different kinds of noise embedded in chaotic signals. White Gaussian noise, colored Gaussian noise as...

     In this research, we used the support vector machine (SVM), support vector machine combine with wavelet transform (W-SVM), ARMAX and ARIMA models to predict the monthly values of precipitation. The study considers monthly time series data for precipitation stations located in Hamedan province during a 25-year period (1998-2016). The 25-year simulation period was divided into 17 years for t...

2011
Kyung-Woo Ko Dae-Chul Kim Wang-Jun Kyung Yeong-Ho Ha

v o w i s s c o bstract. Color embedding and recovery are investigated using a avelet transform that enables color information to be hidden in ray images and then retrieved to recover color images. In a waveet transform, high-frequency subbands are replaced by chromiance information from an image, yet the use of subbands can ause some loss of details and saturation. Therefore, this article ropo...

Hadi Homaei Mahmuod Akbari Mohammad Heidari

In this paper, a fault diagnosis system based on discrete wavelet transform (DWT) and artificial neural networks (ANNs) is designed to diagnose different types of fault in gears and bearings. DWT is an advanced signal-processing technique for fault detection and identification. Five features of wavelet transform RMS, crest factor, kurtosis, standard deviation and skewness of discrete wavelet co...

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