This paper presents time-frequency multiresolution wavelet analysis on power system transients. Since it is difficult to analyze transients on-site due to a vast amount of data recorded from a digital transient recorder, it is imperative to develop an intelligent recorder which has the ability to detect and classify different types of power system transients. In order to develop a good approach...

To my family, in Korea and in Atlanta. iii ACKNOWLEDGEMENTS I am deeply indebted to my advisor Dr. Brani Vidakovic for his guidance and support in countless ways. Without his enlightening instruction, great kindness and patience, unwavering enthusiasm and trust, I could not have completed my thesis. I also want to extend my gratitude to my thesis committee members, Dr. for all their careful rev...

Convolution is one of the most widely used digital signal processing operations. It can be implemented using the fast Fourier transform (FFT), with a computational complexity ofO(N logN). The undecimated discrete wavelet transform (UDWT) is linear and shift invariant, so it can also be used to implement convolution. In this paper, we propose a scheme to implement the convolution using the UDWT,...

The symmetry and periodicity properties of the discrete Fourier transform (DFT) allow a variety of useful and interesting decompositions. In particular, by clever grouping and reordering of the complex exponential multiplications it is possible to achieve substantial computational savings while still obtaining the exact DFT solution (no approximation required). Many “fast” algorithms have been ...

In this paper we present a new approach to ltering and reconstruction of periodic signals. The tool that proves to handle these tasks very eeciently is the discrete Zak transform. The discrete Zak transform can be viewed as the discrete Fourier transform performed on the signal blocks. It also can be considered the polyphase representation of periodic signals. Fast ltering-decimation-interpolat...

Denoising of images using hybrid approach has been a predominant scenario in the current trends. The hybrid approach refers in giving up a combined framework to utilize the advantage of both Fourier and wavelet domain schemes. The noisy images including their Region of Interest (ROI) can yield encouraging results, when obtained through the proposed hybrid approach when comparing to the single t...

introduction: wavelet transform is one of the useful and suitable tools for time series and signal analysis. nowadays wavelet transform is frequently used in geophysical data processing and interpretation, especially seismic data. however, the use of this method isn’t widespread in gravity and geomagnetic. fedi and quarta (1998), martelet et al. (2001) and de oliveira lyrio (2004) used the wave...

-Steganography method used in this paper is based on biometrics. And the biometric feature used to implement steganography is skin tone region of images. Here secret data is embedded within skin region of image that will provide an excellent secure location for data hiding. For this skin tone detection is performed using HSV (Hue, Saturation and Value) color space. Additionally secret data embe...

The classical method of numerically computing the Fourier transform of digitizedfunctions in one or in ddimensions is the so-called discrete Fourier transform ( D F T ) , efficiently implemented as Fast Fourier Transform ( F F T ) algorithms. In m n y cases the D F T is not an adequate appmximation of the continuous Fourier transform. The method presented in this contribution provides accurate ...