Using short-time Fourier transform and wavelet packet filter banks for improved frequency measurement in a Doppler robot tracking system

Gas pipeline small leakage feature extraction based on LMD envelope spectrum entropy and PCA–RWSVM

“…The short-time Fourier transform, which uses sliding time windows to capture frequency features as functions of time, has limitations in terms of time and frequency resolution (Kuang and Morris, 2002). The Wigner distribution is part of the Cohen class of distributions, which is a basic timefrequency representation and its use is popular in nonstationary signal analysis.…”

Natural gas pipeline small leakage feature extraction and recognition based on LMD envelope spectrum entropy and SVM

“…However, most signals encountered in practice do not satisfy such conditions, and, correspondingly, non-stationary signal processing methods have emerged in recent decades-in particular, the time-frequency method, which has been widely used in vibration signal processing. Nevertheless, common time-frequency methods, such as the short time Fourier transform (STFT) and the Wigner-Ville distribution (WVD), have limitations of their own [7][8][9][10]. The STFT, which uses sliding time windows to capture frequency features as functions of time, faces limitations in terms of time and frequency resolution.…”

Parameter estimation of low-voltage distribution systems in transient processes: Algorithm and simulation for RL circuits

“…The existing techniques, such as zero crossing technique [1,2], level crossing technique [3], least squares error technique [4][5][6], Newton method [7], Kalman filter [8][9][10][11][12], Fourier transform [13][14][15][16][17][18][19], wavelet transform [18], genetic algorithm [20], show good characteristics and better application results in processing the pure sinusoidal signals and multiple sinusoidal signals, but these techniques are not adaptive to be applied to processing exponential signals. In [21][22][23], Jun-Zhe Yang, Chih-Wen Liu and Ying-Hong Lin present two new algorithms, namely smart DFT (SDFT) and extended DFT (EDFT), for cases with waveforms consisting of integer and non-integer harmonics as well as exponential DC-offset terms.…”