Obtaining a good similarity matrix is extremely important in subspace clustering. Current state-of-the-art methods learn the through self-expressive strategy. However, these directly adopt original samples as set of basis to represent itself linearly. It difficult accurately describe linear relation between real-world applications, and thus hard find an ideal matrix. To better samples, we prese...

Accurate simulation of X-ray transforms of representative objects plays an important role in the evaluation and improvement of CT reconstruction algorithms. In this paper, we formulate the X-ray transform and 3D Radon transform for ellipsoids and tetrahedra, and verify the resulting formulas by numerical simulation. Here the ellipsoids and tetrahedra may be arbitrarily positioned and rotated. L...

The luminance non-linearity introduced by many medical imaging devices often affects the performance of medical image processing techniques. Image enhancement plays an important pre-processing step in medical image processing methods. In this paper, we present a new automatic method for medical image contrast enhancement based on gamma correction. In this method, a global gamma value is calcula...

sally used to monitor photodetector, or more commonly photodiode currents. These photodetectors bridge the gap between a physical event, light, and electronics. There are a variety of amplifier configurations to select from and the choice is based on noise, bandwidth, offset, and linearity. The most popular design approach is shown in Figure 1. A considerable amount has been written on the perf...

The size-Ramsey number r̂(F ) of a graph F is the smallest integer m such that there exists a graph G on m edges with the property that every colouring of the edges of G with two colours yields a monochromatic copy of F . In 1983, Beck provided a beautiful argument that shows that r̂(Pn) is linear, solving a problem of Erdős. In this note, we provide another proof of this fact that actually gives...

for obtaining reservoir petrophysical properties, for example porosity, non-destructive methods such as x-ray computed tomography, ct, seems to be precise and accurate. porosity is deducted from the ct image with a single scan via different techniques, such as pore space detection by image segmentation techniques then correlation with porosity. more than one hundred samples with carbonate litho...

There are considerable rates of pediatrics trauma referring emergency department following a traumatic event. The worried parents are requesting for the most sensitive diagnostic test, so emergency physicians ask them to underwent brain computed tomography (CT) scan. Lower threshold of decision making regarding use of brain CT scan results in huge number of normal imaging. On the other hand, ra...

Background: With the introduction of computed tomography in diagnostic radiology a new and fundamentally different imaging modality has become available. Meanwhile, it is clear that the absorbed doses by the patients during CT were relatively high in comparison with those of other diagnostic radiology techniques. The aim of this survey was to determine the average absorbed dose in Yazd provin...

We consider nonparametric estimation and testing of linearity in a panel of intercorrelated time series. We place the emphasis on the situation where there are many time series in the panel but few observations for each of the series. The intercorrelation is described by a latent process, and a conditioning argument involving this process plays an important role in deriving the asymptotic theor...