in this paper the author considers a general method, based on time domain samples for spectral manipulation of time limited signals. first, the original signal is divided into some frames in the time domain. then, by presenting a suitable theoretical and computational algorithm, and using a method for improving the speed of convergence, we find the local bandwidth of each frame; thereby, each f...

the record of human brain neural activities, namely electroencephalogram (eeg), is generally known as a non-stationary and nonlinear signal. in many applications, it is useful to divide the eegs into segments within which the signals can be considered stationary. combination of empirical mode decomposition (emd) and hilbert transform, called hilbert-huang transform (hht), is a new and powerful ...

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 ...

introduction: it has been reported that cardiovascular effects are among the possible health effects of being exposed to extremely low frequency electromagnetic fields (elf emss). material and methods: this study has been conducted to evaluate the long term effects of exposure to magnetic and electric fields on electrocardiogram signal changes. nine power transmission posts having different vol...

based on the compressed sensing theory, if a signal is sparse in a suitable space, by using the optimization methods, signal could be accurately reconstructed from measurements that are significantly less than the theoretical shannon requirements. the sparse representation may exist for the signal and it is not available for the noise; this could be used to distinguish these two. on the other h...

A detection method based on sensitization of a squared double differentiated signal is developed which discriminates the turbulent zones from laminar zones quite accurately. The procedure adopts a variable threshold and a variable hold time of the order of the Kolmogorov time scale. The output file so generated, includes all the information for further analysis of the turbulent signal.

Introduction: It has been reported that cardiovascular effects are among the possible health effects of being exposed to extremely low frequency electromagnetic fields (ELF EMSs). Material and Methods: This study has been conducted to evaluate the long term effects of exposure to magnetic and electric fields on electrocardiogram signal changes. Nine power transmission posts having different vol...

Background: With increasing age, some changes appeared in specifications of vessels which including dimensions and elasticity in their. The changes in parameters such as resistance, inertance and compliance vessels appear and eventually changes in the environmental pulse releases are in circulation. These changes clearly appear in specification of photoplethysmogram particularly in the size and...