Short time Fourier transform (STFT) is used to represent signals in time and frequency domains and depends on window size. In MATLAB, a function “spectrogram” is used to detect frequencies and their exact order to analyze signals using STFT. Color bars shown in figures are indicating low to...
We have assessed the performance of our surrogate method by comparing our results with those obtained from a non-stationary surrogate algorithm based on discrete wavelet transform. Results confirm that, compared with stationary Fourier-based and non-stationary DWT-based surrogate algorithms, our method ...
whereais a scale parameter,bis a translation parameter, andψ(t)is the wavelet function. A scalogram is the absolute value of the CWT coefficients of a signal. First, we built a continuous wavelet transform filter bank using Morse (3, 60) wavelets; then, with continuous wavelet, the 30-...
Unlike the present work, their approach uses the standard discrete wavelet transform (DWT) without adding any additional information onto the structure assumed a priori. In [30], a chain structure is assumed to model the spectrogram of audio signals obtained from their short-time Fourier transform...
ECG spectrogrampower spectral densitycardiac diagnosisMost of the clinically useful information carried by the ECG is found in the morphology of the QRS complexes and in the T wave, measured as amplitude, deformations and duration. The aim of the study is to detected after wavelet transform, ECG...
Set the parameters for the mel-frequency spectrograms. Use the same window, or frame, duration as in the scattering transform, 0.22 seconds. Set the hop between windows to 10 ms. Use 40 frequency bands. Get segmentDuration = 8192*(1/8000); ...
Liu et al. proposed the generalized discrete Fourier transform, which reduces the original calculation while solving these problems [9]. S transform (ST) ST can provide time-frequency spectrograms with higher resolution than WT. However, the window function of the S-transform is poorly adaptive ...
The evaluation of results validated that the free-swimming device and the tuned wavelet transform together can efficiently lead to reliable underwater leakage detection, as well as the influence of the leakage size in plastic water-filled pipes. Keywords: acoustic sensors; acoustic signals; free-...
Keywords: waveform distortion; high-frequency spectral components; wavelet transform; modified estimation of signal parameters by rotational invariance technique (ESPRIT); power quality 1. Introduction Modern distribution systems are characterized by the simultaneous presence of renewable energy sources, storage...
For this pur- pose, we use wavelet scattering transform (WST) and continuous wavelet transform (CWT) as the wavelet analysis approaches for 1D-convolutional neural network (CNN) and 2D-CNN modeling, respectively. These features are insensitive to translations of the input on an invariance scale ...