The purpose of this study was to identify the formation interfaces from geophysical well log data using the wavelet transform, and a combination of the wavelet transform and the Fourier transform methods. In the wavelet transform method, the identification of formation interfaces is based on the wavelet coefficients from the wavelet transform of spontaneous potential (SP) log and gamma ray (GR)...

According to the short-time Fourier transform theory and principle of digital filtering, this paper established a mathematical model called collection of voice signal collection at different spectrum. The voice signal was a non-stationary process, while the standard Fourier transform only applied to the periodic signal, transient signals or stationary random signal. Therefore, the standard Four...

Harmonic selection is a useful mechanism for speech enhancement. However, there is difficulty in detecting harmonic structure in the spectrum in the presence of noise or interfering speech. In this paper we address the problem of applying the reassignment method to produce a higher-resolution spectrum for improving the harmonic selection. The reassignment method is to assign the value of the sp...

There is continuous research effort into the expansion and refinement of transform techniques for audio signal processing needs, yet the two-dimensional Fourier transform has seldom been applied to audio. This is probably because audio does not readily allow the application of a 2D transform, unlike images for which its use is common. A signal mapping is first required to obtain a two-dimension...

To replace the film recording aspect of performing optical correlation, conventional real-time joint-transform correlation (JTC) optical systems make use of a spatial light modulator (SLM) located in the Fourier plane to record the joint-transform power spectrum (JPS) to achieve real-time processing. The use of an SLM in the Fourier plane, however, is a major drawback in these systems because S...

This paper is part 5 in a series of papers about the Discrete Fourier Transform (DFT) and the Inverse Discrete Fourier Transform (IDFT). The focus of this paper is on the spectrogram. The spectrogram performs a Short-Time Fourier Transform (STFT) in order to estimate the spectrum of a signal as a function of time. The approach requires that each time segment be transformed into the frequency do...

The new Proposed design has been designed and developed by novel parallel-pipelined Fast Fourier Transform (FFT) architecture. The most important and fastest efficient algorithm is a FFT. FFT is used to computes the Discrete Fourier Transform (DFT). FFT is mainly applied in autocorrelation, spectrum analysis, linear filtering and pattern recognition system. The proposed architectures were desig...

-This paper develops a novel spectrum enhancement method to simplify the spectrum representation. It uses a forward synchronous transform to convert three phase current signals into the two current signals in the synchronous reference frame. The spectrum obtained by applying Fast Fourier Transform (FFT) to one of the transformed current signals is then maximized by varying the initial phase in ...

A new signal-adaptive joint time-frequency distribution for the analysis of nonstationary signals is proposed. It is based on a fractionalFourier-domain realization of the weighted Wigner distribution producing auto-terms close to the ones in the Wigner distribution itself, but with reduced cross-terms. Improvement over the standard time-frequency representations is achieved when the principal ...