ECG signal and generally biomedical signals change their statistical properties over time. Researchers can use multiresolution techniques for analyzing non-stationary signals. Traditional analysis techniques like fourier transform and short time fourier Transform are confined to stationary signals only. Multiresolution techniques like Wavelet transform is a powerful instrument in catching zerod...

one of the most common signals used for achieving high range resolution in radar is stepped-frequency signals. when a target is stationary in these radars, dft (discrete fourier transform) based processing is used to attain high range resolution profile (hrrp). however, in the case of moving target, due to spreading of the echo signal spectrum, dft based processing is not optimal and decreases ...

a r t i c l e i n f o JEL Classification: C22 F31 Keywords: Purchasing power parity Real effective exchange rate Transition countries Sequential Panel Selection Method Panel KSS unit root test Fourier function Policy implications This study applies the Sequential Panel Selection Method (SPSM), proposed by Chortareas and Kapetanios (2009) to test the validity of long-run purchasing power parity ...

This paper presents a novel family of rigorous and flexible mathematical self-calibration additional parameters (APs) for airborne camera calibration. It is pointed out, that photogrammetric self-calibration can – to a very large extent – be considered as a function approximation problem in mathematics. Based on the mathematical approximation theory, we suggest that Fourier series (trigonometri...

The windowed Fourier transform (short time Fourier transform) and the S-transform are widely used signal processing tools for extracting frequency information from non-stationary signals. Previously, the windowed Fourier transform had been adopted for signals on graphs and has been shown to be very useful for extracting vertex-frequency information from graphs. However, high computational compl...

The main purpose of this study is to test the stability ecological footprint and its sub-components in Mexico, Indonesia, Nigeria, Turkey (MINT) by performing Fourier unit root test, which yields reliable results presence an unknown number form breaks, on data obtained over period 1961–2016. Unit tests provide information regarding future behaviors based previous series. In respect, suggestions...

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...

In this paper, we propose the Fourier frequency vector (FFV), inherently, associated with multidimensional Fourier transform. With the help of FFV, we are able to provide physical meaning of so called negative frequencies in multidimensional Fourier transform (MDFT), which in turn provide multidimensional spatial and space-time series analysis. The complex exponential representation of sinusoid...