vertebrobasilar insufficiency is the cause of cerebrovascular accidents in 20% of cases. there are few reports regarding spectral doppler indices (sdis) of vertebral arteries (vas) normal blood flow. the objective of this study was to provide basic reference data about sdis of vas normal blood flow separately and in comparison with internal carotid arteries (icas) and common carotid arteries (c...

PCG signal pattern classification, also known as auscultation pattern recognition, was one of the efficient computer-based methods applied to medical decision making. PCG Pattern recognition generally is interpreted in two ways. The most general definition includes recognition of patterns in any type of PCG dataset and is called uniform PCG pattern classification this discriminate peaks of hear...

An experimental study is conducted to show the effect of the change in bandwidth of light on the spectral degree of coherence at a pair of points in the cross section of a beam. For this purpose a polychromatic source and a monochromator with variable entrance and exit slits were used to produce a variable bandwidth source. The classic Young's interferometer was used to produce an interference ...

Spectral shaping is one of the primary technical challenges in spectrally constrained multiple access applications. In this paper, we introduce an efficient orthogonal CDMA-based spectral shaping technique. In our approach, termed CodeHopping CDMA, users are allowed to hop between available spreading codes in an orthogonal fashion with different frequencies. We show that code hoping patterns ca...

The synthesis of arbitrarily shaped femtosecond pulses by spectral filtering in a temporally nondispersive grating apparatus is demonstrated. Spectral filtering is accomplished by utilizing spatially patterned masks to modify the amplitude and the phase of the optical frequency components that are spatially dispersed within the apparatus. We are able to pattern spectra over a large dynamic rang...

In this paper we present a very effective method for texture segmentation and analysis using a local spectral method. The idea is to use a modular pattern detection in textured images based on the use of a Pseudo-Wigner Distribution (PWD) followed by a decorrelation procedure that consists of a principal component analyzer (for texture segmentation). The goal is to combine the advantages of a h...

Nearly perfect speech recognition was observed under conditions of greatly reduced spectral information. Temporal envelopes of speech were extracted from broad frequency bands and were used to modulate noises of the same bandwidths. This manipulation preserved temporal envelope cues in each band but restricted the listener to severely degraded information on the distribution of spectral energy....

INTRODUCTION The chemical shift artifact (CSA) results from temporally undersampling a spatial-spectral distribution along a tilted k-t trajectory. This is illustrated in Fig. 1 for the case of H imaging. Figure 1(a) shows a typical H spatial-spectral distribution, in which the two predominant spectral components are from lipid and water protons. Figure 1(b) shows the k-t space sampling pattern...

We suggest a spectral histogram, defined as the marginal distribution of filter responses, as a quantitative definition for a texton pattern. By matching spectral histograms, an arbitrary image can be transformed to an image with similar textons to the observed. We use the chi(2)-statistic to measure the difference between two spectral histograms, which leads to a texture discrimination model. ...