Time-varying spectra of non-stationary time-series commonly used are spectrograms from the Short-Time Fourier Transform (STFT). The most prominent limitation of the Fourier Transform is that of frequency resolution. To overcome the limitation the Wavelet Transform, Wigner-Ville Distribution and the Min-Norm subspace method have been applied for spectrum estimation of non-stationary signals caus...

The measurement algorithms applied in power quality measurement systems are based on Fast Fourier Transformation. That one-dimension frequency analysis is sufficient in many cases. However, to illustrate the character of the signal in a more comprehensive manner, it is crucial to represent the investigated signal on time-frequency plane. There are a lot of time-frequency representations (TFR) f...

Heart sounds and murmurs are timevarying signals that would best be analyzed using timefrequency analysis. Windowed Wigner-Ville distribution (WWVD) and smooth windowed Wigner-Vffle distribution (SWWVD) are used to obtain the timefrequency representation of the signal. Determination of parameter setting of WWVD and SWWVD will eliminate the cross-terms and improve time frequency representation. ...

Using ESM, RWR and ARM missiles pose significant limitations to the performance of the radar systems in new battles. In these wars, MTI radars are commonly used with high Power to achieve long ranges, therefore they are easily detectable by the enemy EW receivers, and so they lose their effectiveness. In addition to having the ability of anti-Jamming and good ECCM, the radar systems should to u...

Heart rate variability (HRV) is derived from the time duration between consecutive heart beats. The HRV is to reflect the heart’s ability to adapt to changing circumstances by detecting and quickly responding to unpredictable stimuli to cardiac system. Depressed HRV is a powerful predictor of mortality and of arrhythmic complications in patients after diseases like acute Myocardial Infarction. ...

Digital intercept receivers are currently moving away from Fourier-based analysis and towards classical time-frequency analysis techniques, such as the Wigner-Ville distribution, ChoiWilliams distribution, spectrogram, and scalogram, for the purpose of analyzing low probability of intercept radar signals (e.g. triangular modulated frequency modulated continuous wave and frequency shift keying)....

The structure is said to be damaged if there a permanent shift in the post-event natural frequency of as compared with pre-event frequency. To assess damage structure, time-frequency approach that can capture and required. In this study, determine these frequencies, local maximum synchrosqueezing transform (LMSST) method employed. Through simulation results, we have shown traditional methods su...