We consider radial solutions blowing up in infinite time to a parabolicelliptic system in N -dimensional Euclidean space. The system was introduced to describe the gravitational interaction of particles. In the case where N ≥ 2, we can find positive and radial solutions blowing up in finite time. In the present paper, in the case where N ≥ 11, we find positive and radial solutions blowing up in...

A procedure is described for estimating an optimum kernel for the detection by convolution of signals among Poissonian noise. The technique is applied to the detection of x-ray point sources in XMM-Newton data, and is shown to yield an improvement in detection sensitivity of up to 60% over the sliding-box method used in the creation of the 1XMM catalog.

Thus, consider a set of matched points ui ↔ ui for i = 1, . . . , 6 and suppose that the points x1, . . . ,x4 corresponding to the first four matched points lie in a plane in space. Let this plane be denoted by π. Suppose also that no three of the points x1, . . . ,x4 are collinear. Suppose further that the points x5 and x6 do not lie in that plane. Various other assumptions will be necessary i...

AMract-The minimax approach to the design of systems that are robust with respect to modeling uncertainties is studied using a game theoretic formulation in which the peiformance functional and the sets of modeling uncertainties and admissible design policies are arbitrary. The existence and characterization of minimax robust solutions that form saddle points are discussed through various metho...

We investigate, using simulated galaxy catalogues, the completeness of searches for massive clusters of galaxies in redshift surveys or imaging surveys with photometric redshift estimates, i.e. what fraction of clusters (M > 10hM⊙) are found in such surveys. We demonstrate that the matched filter method provides an efficient and reliable means of identifying massive clusters even when the redsh...

High dimensional data sequences, such as video clips, can be modeled as trajectories in a high dimensional space and, and usually exhibit a low dimensional structure intrinsic to each distinct class of data sequence [1]. In this paper, we exploit a fibre bundle formalism to model various realizations of each trajectory, and characterize these high dimensional data sequences by an optimal operat...

In this paper, Gaussian and elliptic high pass filters are analyzed for image sharpening qualitatively and quantatively . The filters are implemented in frequency domain using matlab software. Experiments are performed to compare the performance of both the filters ,processed images are presented. The results demonstrate that elliptic yields better results.

A common pattern recognition problem is finding a library element closest, in some sense, to a given reception. In many scenarios, optimal detection requires N matched filters for N library elements. Since N can often be quite large, there is a need for suboptimal techniques that base their decisions on a reduced number of filters. The use of composite matched filters (CMFs) (also called synthe...

Digital image is often degraded by many kinds of noise during the process of acquisition and transmission. To make subsequent processing more convenient, it is necessary to decrease the effect of noise. There are many kinds of noises in image, which mainly include salt and pepper noise and Gaussian noise. This paper focuses on median filters to remove the salt and pepper noise. After summarizin...