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...

in seismic exploration studies different types of techniques are used to recognize seismic features in terms of their temporal and spatial spectra. variations in frequency content are sensitive to subtle changes in reflection information (castro de matos et al., 2003). in this study the joint time-frequency analysis is used for seismic texture recognition. discrete wavelet transform (dwt) witho...

This paper uses a method for shape reconstruction of a 2-D homogeneous object with arbitrary geometry and known electrical properties. In this method, the object is illuminated by a Gaussian pulse, modulated with sinusoidal carrier plane wave and the time domains’ footprint signal due to object presence is used for the shape reconstruction. A nonlinear feedback loop is used to minimize the diff...

an electric arc furnace (eaf) is known as nonlinear and time variant load that causes power quality (pq) problems such as, current, voltage and current harmonics, voltage flicker, frequency changes in power system. one of the most important problems to study the eaf behavior is the choice of a suitable model for this load. hence, in this paper, a probabilistic three-phase model is proposed base...

abstract time domain reflectometry (tdr) is a widely used method for measuring the dielectric constant (ka) and bulk electrical conductivity (σa) in soils. the tdr-measured σa and ka can be used to calculate the soil solution electrical conductivity, (σp). a theoretical model describing a linear relationship between bulk electrical conductivity, σa, and dielectric constant, ka, in moist soil wa...