most geologic changes have a seismic response but sometimes this is expressed only in certain spectral ranges hidden within the broadband data. spectral decomposition is one of the methods which can be utilized to help interpreting such cases. there are several time-frequency methods including: short-time fourier transform (stft), continuous wavelet transform (cwt), wigner-ville distribution (w...

introduction contrast-enhanced fluid-attenuated inversion recovery (flair) is one of the mri sequences that can be used for detection and evaluation of pathological changes in the brain. in this work, we have studied the effect of different echo times (te) on the maximum relationship between signal intensity and concentration of the contrast agent using the flair sequence. materials and methods...

in this work, time domain analysis is used to solve adler’s equation in order to obtain the required time, for an oscillator under external injection, reaching the steady-state condition. mathematical approach has been applied to fully describe the transient of frequency acquisition in injection-locked lc and ring oscillators considering their time-varying nature. then, the analysis is verified...

We focus on studying the opacity of iron, chromium, and nickel plasmas at conditions relevant to experiments carried out Sandia National Laboratories [J. E. Bailey et al., Nature 517, 56 (2015)]. calculate photo-absorption cross-sections subsequent for using linear response time-dependent density functional theory (TD-DFT). Our results indicate that physics channel mixing accounted in TD-DFT le...

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...