In this work, we analyse a pair of two-dimensional coupled reaction-diusion equations known as the Gray-Scott model, in which spot patterns have been observed. We focus on stationary patterns, and begin by deriving the asymptotic scaling of the parameters and variables necessary for the analysis of these patterns. A complete bifurcation study of these solutions is presented. The main mathematic...

Automatic thresholding of the gray-level values of an image is very useful in automated analysis of morphological images, and it represents the first step in many applications in image understanding. Recently it was shown that by choosing the threshold as the value that maximizes the entropy of the l-dimensional histogram of an image, one might be able to separate, effectively, the desired obje...

the purpose of resent research is to analysis and compares performance evaluation models of selected investment companies in tehran stock exchange market in the field of their portfolio management. the duration of research was between years 2009-2014. statistical society the research is consisting of all active investment companies in in tehran stock exchange market which were 30 companies. vol...

the pathological scrotum Conventional high resolution gray-scale ultrasonography is excellent at evaluating scrotal pathology. The particular value of gray-scale ultrasonography is that it may distinguish between intra-testicular and extra-testicular pathology with 90 -99% accuracy (Krone and Carroll, 1985; Narayan et al., 1981). This distinction is of importance as the majority of intra-testic...

During the investigation of intractable epilepsy, neuronal migration anomalies [NMA] were discovered in three patients. The first patient had abnormally positioned gray matter within the walls of both lateral ventricles. The second patient had a post operative cystic area in the right parietal-occipital lobes and an area of NMA within the right temporal lobe. The third patient had abnormally th...

OBJECTIVE: To determine the role of transrectal ultrasound, especially in association with color Doppler, in the diagnosis of prostate cancer. MATERIALS AND METHODS: Eighty-four cases of patients who underwent transrectal biopsy were prospectively analyzed. In all patients, besides the traditional gray-scale sonogram, color Doppler study was performed in search of hypervascular foci. The result...