SOLVABILITY EXPLORATION OF SEGMENTATION PROBLEM WITH LINEAR CONVOLUTION ALGORITHMS

The paper is dedicated to decidability exploration of market segmentation problem with the help of linear convolution algorithms. Mathematical formulation of this problem represents interval task of bipartite graph cover by stars. Vertices of the first partition correspond to types of commodities, vertices of the second – to customers groups. Appropriate method is offered for interval problem reduction to two-criterion task that has one implemented linear convolution algorithm. Unsolvability with the help of linear convolution algorithm of multicriterion, and consequently interval, market segmentation problem is proved

First observation of strong OZI rule violation in πN\pi N interactions

The data of the CERN WA56 experiment that triggered the fast proton produced in the $\pi^{+}p$ and $\pi^{-}p$ interactions at beam momenta 20 GeV/c and 12 GeV/c, respectively, are used to analyse the final states $p_{f} \phi (\omega)\pi^{\pm}$. A large excess (up to two orders of magnitude) of the $\phi/\omega$ cross sections ratio over the OZI prediction is observed

The impact of stress on the physical, psychological and behavioral health components of students

students, stress, health, студенты, стресс, здоровь

Research of Stability of Vector Problem of spanning Tree with topological Criteria

A multicriterial statement of the above mentioned problem is presented. It differes from the classical statement of Spanning Tree problem. The quality of solution is estimated by vector objective function which contains weight criteria as well as topological criteria (degree and diameter of tree). Many real processes are not determined yet. And that is why the investigation of the stability is very important. Many errors are connected with calculations. The stability analysis of vector combinatorial problems allows to discover the value of changes in the initial data for which the optimal solution is not changed. Furthermore, the investigation of the stability allows to construct the class of the problems on base of the one problem by means of the parameter variations. Analysis of the problems with belong to this class allows to obtaine axact and adecuate discription of mode

Fractal Graphs and their Properties

The idea of representing urban structure and various communication systems (water and energy supply, telephone and cable TV networks) as fractal objects is not absolutely new. However, known works, devoted to this problem use models and approaches from fractal physics. For example, to simulate urban growth Diffusion Limited Aggregation (DLA) model and Dielectric Breakdown (DB) model are used. This study introduces a different approach. Net structure of communication system is described by a graph of special type called regular G(l,r,n)-graph. Authors provide description of such graph, develop iterative process for its generation and prove its self-similarity, i.e. that every regular graph is a pre-fractal. After the infinite number of steps this process generates a fractal. The devised algorithm for generation and grathical representation of regular G(l,r,n)-graphs with different values of l,r and n has been programmed to receive computer simulations. For optimal graphic presentation of pre-fractals the Optimal Space Ordering method was suggested. It is based on the minimization of the >graph energygraph energy< is directly related to the graph's fractal properties. For G(3,3,n) and G(4,4,n) graphs fractal dimensions calculated by different methods are the same (D=1,5 and D=2 respectively), while topological dimension of both graphs is 1

Splenic morphometric characteristics in infectious mononucleosis (ultrasonic study)

The spleen is a secondary immune and the largest organ of the reticuloendothelial system, actively involved during infectious mononucleosis. Clinically, assessing a degree of organ involvement in the pathological process seems unlikely. As a rule, only palpation and percussion are used to determine the size of the spleen, which represents a late and subjective sign of potential splenomegaly. Ultrasound examination provides ample opportunities to estimate the spleen size during infectious mononucleosis. Our study was aimed at identifying morphometric and Doppler ultrasound changes in the spleen in patients with infectious mononucleosis. Materials and methods. There were enrolled 24 patients with infectious mononucleosis to be compared with 30 healthy medical institute students in control group. All participants underwent splenic ultrasound examination. Spleen echotexture and contour clarity together with measuring linear dimensions: length, width, and thickness were analyzed. Splenic artery and vein velocity parameters were measured at the gates of the spleen. Elastographic window for fibroelastometry was positioned within the window for standard grayscale examination. Measurements were performed at 5 or more points of the spleen parenchyma at least 4—5 mm away from the capsular zone and the zone of large vessels. Based on the morphometric measurements obtained, the mass, spleen mass coefficient (SMC), as well as the spleen mass/body height ratio and spleen mass/body surface area ratio were calculated. Results. We found that patients with infectious mononucleosis had the length, thickness and weight of the spleen significantly greater than those observed in control group. However, the mass of the spleen varies widely and justified to calculate the CMS as an objective criterion to assess the size of the spleen. It was revealed that infectious mononucleosis may proceed in one of the three variants of the splenic response: decreased size, CMR &lt; 1.5; normal size, CMR ranged from 1.5 to 4; splenomegaly, CMR &gt; 4. Splenomegaly is associated with increased organ stiffness, peak blood flow velocity and pressure in v. lienalis, as well as periportal lymphadenopathy. Identified changes are characteristics of young patients. Conclusion. Ultrasound examination of the spleen is of high diagnostic value for patients with infectious mononucleosis allowing highly accurate assessment state of the immune organs in the acute disease period. At the preclinical stage, gradation of splenomegaly is possible depending on its intensity, assessed hemodynamics and organ stiffness