An Adaptative Neuro-Fuzzy Inference System (ANFIS) is developed to predict the acoustic form function (FF) for an infinite length cylindrical shell excited perpendicularly to its axis. The Wigner-Ville distribution (WVD) is used like a comparison tool between the calculated FF by the analytical method and that predicted by the neuro-fuzzy technique for a copper tube. During the application of t...

Time-frequency representations have been of great interest in the analysis and classification of non-stationary signals. The use of highly selective transformation techniques is a valuable tool for obtaining accurate information for studies of this type. The Wigner-Ville distribution has high time and frequency selectivity in addition to meeting some interesting mathematical properties. However...

The Wigner-Ville Distribution (WVD) and Pseudo-Wigner-Ville Distribution (PWVD) are very popular and effective methods for detecting Linear Frequency Modulated (LFM) signals in noisy environments. Hough transform is also widely used method for detection and parameter estimation of chirp signals. However, when there are signals with very different strength from each other, it is difficult to sim...

The large variance of the Wigner Ville distribution makes smoothing essential for producing readable estimates of the time varying power spectrum of noise corrupted signals Since linear smoothing trades reduced variance for increased bias of the signal components we explore two nonlinear estimation techniques based on soft thresholding in an orthonormal basis representation Soft thresholding pr...

Time-frequency analysis has been found to be effective in monitoring the transient or timevarying characteristics of machinery vibration signals, and therefore its use in machine condition monitoring is increasing. This paper proposes the application of time-frequency methods, which can provide more information about a signal in time and in frequency and gives a better representation of the sig...