Wavelet transform has emerged recently as a tool to detect web traffic anomalies. Under the assumption that an attack produces a substantial variation on the web traffic, to identify anomalies wavelet based methods consider a threshold value for deciding if wavelet coefficients are associated to anomalies or not. This paper explores different strategies to define the threshold value in associat...

A discrete wavelet transform based dynamic supply current analysis technique for detecting the catastrophic faults in analog circuits containing transistor is investigated in the paper. Some considerations due to a problem of fault localization using multiresolution approximation and the illustrative numerical example are presented.

The discrete wavelet transform (DWT) has several advantages of multiresolution analysis and subband decomposition, which has been successfully used in image processing. However, the shift-variant property is intrinsic due to the decimation process of the wavelet transform, and it makes the wavelet-domain motion estimation and compensation inefficient. To overcome the shift-variant property, a l...

Electric power quality is an aspect of power engineering that has been with us since the inception of power systems. To investigate this issue, engineers have proposed various schemes to deal with the power disturbance waveforms. Among these approaches, wavelet transform is one of the most frequently used algorithms to analyze the power signal. This paper presents a new design of discrete wavel...

We present and discuss a method to identify substructures in combined angularredshift samples of galaxies within Clusters. The method relies on the use of Discrete Wavelet Transform (hereafter DWT) and has already been applied to the analysis of the Coma cluster (Gambera et al. 1997). The main new ingredient of our method with respect to previous studies lies in the fact that we make use of a 3...

The aim of this study is to propose a method for analyzing measured signal obtained from functional Near-Infrared Spectroscopy (fNIRS), which is applicable for neuroimaging studies for car drivers. We developed a signal processing method by multiresolution analysis (MRA) based on discrete wavelet transform. Statistical group analysis using Z-score is conducted after the extraction of task-relat...

Digital image watermark has been studied as object. It analyzed the typical digital watermark algorithms based on the space domain and transform domain and key researched watermarking algorithm based on discrete wavelet transform. It has designed and improved blind watermarking algorithm and color image watermarking algorithm. Finally, based on the two improved watermarking algorithm, it has de...

This paper aims at reviewing the recent published works dealing with industrial applications of wavelet and, more generally speaking, multiresolution analysis. After a quick recall in a simple overview of the basics of wavelet transform and of its main variations, some of its applications are reviewed domain by domain, beginning with signal processing, continuous and discrete wavelet transform ...

In this paper we study a generalization of the Donoho-Johnstone denoising model for the case of the translation invariant wavelet transform. Instead of soft-thresholding coeecients of the classical orthogonal discrete wavelet transform, we study soft-thresholding of the co-eecients of the translation invariant discrete wavelet transform. This latter transform is not an orthogonal transformation...

A new analysis method using wavelet domain for steady-state operating condition of power system is developed and introduced. Based on wavelet-Galerkin theory, the system components such as resistor, inductor, capacitor, transmission lines, and switching devices are modeled in discrete wavelet domain for the purpose of steady-state analysis. To solve system equations, they are transferred to wav...