نتایج جستجو برای: wavelet

تعداد نتایج: 38198  

2003
Rade Kutil

Wavelet based image compression has proved its superiority over DCT based methods. However, wavelet based techniques did not have so much success in video coding because motion compensation usually produces residuals that are not suitable for wavelet compression. This paper discusses a motion compensation technique which should fit naturally into wavelet based compression schemes. The motion co...

Journal: :آب و خاک 0
پریوش طوفانی ابوالفضل مساعدی احمد فاخری فرد

abstract obligatory modelling of precipitations in various periods, have a lot of problems and weakness because of their casual nature in time and space. moreover, their uncertainty in predictions, reduce credibility of estimations which have done via these models. wavelet is one of the novel and very effective methods in analyzing of time series and signals considered in the hydrology in recen...

Journal: :تحقیقات جغرافیایی 0
هوشنگ قائمی سعید جهانبخش بهروز ساری صراف هوشنگ قائمی سعید جهانبخش فرناز پوراصغر

continuous and lengthy droughts in previous years not only in the southern provinces of iran but also in the whole country necessitate optimized water management. indian ocean and adjacent seas in south of iran are suppliers of part of the humidity in the region and the variation on indian ocean sea surface temperature has an important role in evaporation from oceans and input humidity into atm...

Journal: :journal of medical signals and sensors 0
ahmad keshtkar hadi seyedarabi peyman sheikhzadeh seyed hossein rasta

there are a variety of electrocardiogram (ecg) based methods to detect myocardial infarction (mi) patients. this study used the signal averaged electrocardiogram (saecg) and its wavelet coefficient as an index to detect mi. orthogonal leads signals from 50 acute myocardial infarction (ami) and 50 healthy subjects were selected from the national metrology institute of germany (ptb diagnostic dat...

2005
Arthur Asuncion

Wavelets are powerful mechanisms for analyzing and processing digital signals. The wavelet transform translates the time-amplitude representation of a signal to a time-frequency representation that is encapsulated as a set of wavelet coefficients. These wavelet coefficients can be manipulated in a frequency-dependent manner to achieve various digital signal processing effects. The inverse wavel...

Synthetic Aperture Radar (SAR) images are inherently affected by a multiplicative noise-like phenomenon called speckle, which is indeed the nature of all coherent systems. Speckle decreases the performance of almost all the information extraction methods such as classification, segmentation, and change detection, therefore speckle must be suppressed. Despeckling can be applied by the multilooki...

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...

Journal: :international journal of advanced design and manufacturing technology 0
mahmuod akbari shahrekord university hadi homaei shahrekord university mohammad heidari islamic azad university

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. 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 coefficients of...

Journal: :journal of medical signals and sensors 0
fatemeh hajiaghababa saeed kermani hamidreza marateb

a cochlear implant is an implanted electronic device used to provide a sensation of hearing to a person who is hard of hearing. the cochlear implant is often referred to as a bionic ear. this paper presents an undecimated wavelet‑based speech coding strategy for cochlear implants, which gives a novel speech processor. the undecimated wavelet packet transform (uwpt) is computed like the wavelet ...

A Zamani, H Parsaei, M Dehbozorgi M Ghofrani Jahromi

Background: Electromyographic (EMG) signal decomposition is the process by which an EMG signal is decomposed into its constituent motor unit potential trains (MUPTs). A major step in EMG decomposition is feature extraction in which each detected motor unit potential (MUP) is represented by a feature vector. As with any other pattern recognition system, feature extraction has a significant impac...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید