this study represents an intelligence procedure for diagnosis simultaneously avian newcastle disease virus, infection bronchitis virus and influenza using heart sound signal. for this aim, the chickens were divided into four groups. the first group was considered as control samples. the second, third and fourth groups were infected with newcastle disease virus, infection bronchitis and avian in...

With good time-frequency discrimination ability and flexible time-frequency windows, wavelet transform is now widely used to analysis various signals in time and frequency domain simultaneously. Because of the simple relation between wavelet spectra and local (evolutionary) power spectra of a signal, a new method based on wavelet transform to estimate the local power spectra of earthquake groun...

so that the gray-scale graphs can be viewed more clearly. This paper presents a fast adaptive time-frequency analysis method for dealing with the signals consisting of stationary components and transients, which are encountered very often in practice. It is developed based on the short-time Fourier transform but the window bandwidth varies along frequency adaptively. The method therefore behave...

this paper illustrates the application of s-transform and continuous wavelet transform (cwt) for fault location in combined overhead line and cable distribution networks. the high frequency transient signals originated by faults are analyzed using s-transform and cwt. the s-transform is found to be applicable in transient based fault location in distribution networks. this technique is an expan...

Time-frequency representation of seismic signals provides a source of information that is usually hidden in the Fourier spectrum. The short-time Fourier transform and the wavelet transform are the principal approaches to simultaneously decompose a signal into time and frequency components. Known limitations, such as trade-offs between time and frequency resolution, may be overcome by alternativ...

AbstructWe consider a multidimensional parameter space formed by inner products of a parameterizable family of chirp functions with a signal under analysis. We propose the use of quadratic chirp functions (which we will call q-chirps for short), giving irise to a parameter space that includes both the time-frequency plane and the time-scale plane as 2-D subspaces. The parameter space contains a...

0018-9251/03/$17.00 @ 2003 IEEE Two-way antenna radiation pattern at frequency w + wc, Slow-time Doppler two-way antenna radiation pattern Pulse bandwidth Speed of light Covariance of w(k,,t) at time t Cross-range aperture length Energy of RJt) Energy of p( t ) Point target refectivity Fourier transform operator Inverse Fourier transform operator Fourier transform of electric field in antenna a...

In the next two lectures, we will continue to expand our toolbox for computing in frequency domain, by adding two important computational tools. The first, the Fast Fourier Transform (FFT) is a family of algorithms for efficiently computing the Discrete Fourier Transform. These algorithms are of great practical importance, as theymake it possible to perform frequency domain analysis of very lar...

We propose a new band-extrapolation method using an iterative Hilbert-transform procedure, which is applicable for band-limited complex-frequency data obtained from a Fourier-transform phase-modulation fluorometer (FT-PMF). Without the band limitation, the real and the imaginary parts of the complex-frequency data obtained from the FT-PMF form a Hilbert-transform pair because of causality. Howe...