Scientific Journal of KubSAU

Polythematic online scientific journal
of Kuban State Agrarian University
ISSN 1990-4665
AGRIS logo UlrichsWeb logo DOAJ logo
Search by author's name Search by title
430 kb

MATHEMATICAL MODEL OF ORGANIZATION OF DISTRIBUTED CALCULATIONS IN A CORPORATE NETWORK ON PREFRACTAL GRAPHS IN VECTOR FORMULATION

abstract 1261702040 issue 126 pp. 564 – 581 28.02.2017 ru 478
In the article we investigate the multicriteria task arising at the organization of distributed calculations in a corporate network. As a mathematical tool to solve the problem we use prefractal graphs, which naturally reflect the structure of relationships in global and corporate networks. The corporate network with the distributed computing system at the solution of a particular task has to be reliable, quickly and qualitatively to make decisions. And every computer in the network should be a part in the solution of the problem, since it is fixed for a certain function. The problem is reduced to cover the prefractal graphs with disjoint simple paths along the edges and vertices. On the set of all admissible coverings we constructed a vector-target function with specific criteria. All these criteria have a specific meaningful interpretation, allowing organizing the calculation of maximum reliability, with minimum time information processing and loading balancing between the network elements. In the article we constructed polynomial algorithms for finding optimal solutions according to specific criteria. For the criteria which are not optimizing the allocated coverings, estimates of the lower and upper bounds are given. For all the algorithms we constructed and substantiated estimation of computational complexity, confirming the advantage of using algorithms on prefractal graphs to classical algorithms on graphs
693 kb

SIMULATION OF PLASMOID AND STRAIMERS IN CONDUCTING ENVIRONMENT

abstract 1291705041 issue 129 pp. 471 – 497 31.05.2017 ru 484
In this work, a model is developed that describes the formation of a plasmoid and streamers in a conducting medium. To describe the contribution of the conductivity currents, we modified the standard electrostatic equation taking into account the vortex component of the electric field. As a result of this generalization, the streamer model is formulated in the form of a system of parabolictype nonlinear equations. As is known, in laboratories it is possible to create a plasmoid with a lifetime of 300- 500 ms and a diameter of 10-20 cm, which is interpreted as a ball lightning. With high-speed photography, a complex structure is detected, consisting of a plasmoid and surrounding streamers. Within the framework of the proposed model, problems are posed about the formation of a plasmoid and the propagation of streamers in an external electric field. In this model, the plasmoid is considered to be a long-lived streamer. The range of parameters in which a plasmoid of spherical shape is formed is indicated. It is established that there are three streamer branching mechanisms. The first mechanism is related to the instability of the front, which leads to the separation of the head of the streamer into two parts. The second mechanism is associated with the instability of the streamer in the base region, which leads to the branching of the streamer with the formation of a large number of lateral streamers closing the main channel of the streamer to the cathode. In numerical experiments, the third branching mechanism observed in experiments connected with the branching of the plasmoid in the cathode region with the closure of the space charge to the anode through the streamer system was observed. The similarity of ball lightning and plasmoid is discussed. If this similarity is confirmed, then the number of theoretical hypotheses concerning the nature of ball lightning, currently more than 200, can be drastically reduced to one described in this article
282 kb

ASYMPTOTICS OF ESTIMATES OF PROBABILITY DISTRIBUTION DENSITY

abstract 1311707070 issue 131 pp. 832 – 860 29.09.2017 ru 484
Nonparametric estimates of the probability distribution density in spaces of arbitrary nature are one of the main tools of non-numerical statistics. Their particular cases are considered - kernel density estimates in spaces of arbitrary nature, histogram estimations and Fix-Hodges-type estimates. The purpose of this article is the completion of a series of papers devoted to the mathematical study of the asymptotic properties of various types of nonparametric estimates of the probability distribution density in spaces of general nature. Thus, a mathematical foundation is applied to the application of such estimates in non-numerical statistics. We begin by considering the mean square error of the kernel density estimate and, in order to maximize the order of its decrease, the choice of the kernel function and the sequence of the blur indicators. The basic concepts are the circular distribution function and the circular density. The order of convergence in the general case is the same as in estimating the density of a numerical random variable, but the main conditions are imposed not on the density of a random variable, but on the circular density. Next, we consider other types of nonparametric density estimates - histogram estimates and Fix-Hodges-type estimates. Then we study nonparametric regression estimates and their application to solve discriminant analysis problems in a general nature space
230 kb

THE LIMIT THEORY OF THE SOLUTIONS OF EXTREMAL STATISTICAL PROBLEMS

abstract 1331709045 issue 133 pp. 579 – 600 30.11.2017 ru 484
Many procedures of applied mathematical statistics are based on the solution of extreme problems. As examples it is enough to name methods of least squares, maximum likelihood, minimal contrast, main components. In accordance with the new paradigm of applied mathematical statistics, the central part of this scientific and practical discipline is the statistics of non-numerical data (it is also called the statistics of objects of non-numerical nature or non-numeric statistics) in which the empirical and theoretical averages are determined by solving extreme problems. As shown in this paper, the laws of large numbers are valid, according to which empirical averages approach the theoretical ones with increasing sample size. Of great importance are limit theorems describing the asymptotic behavior of solutions of extremal statistical problems. For example, in the method of least squares, selective estimates of the parameters of the dependence approach the theoretical values, the maximum likelihood estimates tend to the estimated parameters, etc. It is quite natural to seek to study the asymptotic behavior of solutions of extremal statistical problems in the general case. The corresponding results can be used in various special cases. This is the theoretical and practical use of the limiting results obtained under the weakest assumptions. The present article is devoted to a series of limit theorems concerning the asymptotics of solutions of extremal statistical problems in the most general formulations. Along with the results of probability theory, the apparatus of general topology is used. The main differences between the results of this article and numerous studies on related topics are: we consider spaces of a general nature; the behavior of solutions is studied for extremal statistical problems of general form; it is possible to weaken ordinary requirements of bicompactness type by introducing conditions of the type of asymptotic uniform divisibility
581 kb

PARTICLE DYNAMICS IN METRICS WITH LOGARITHMIC POTENTIAL

abstract 1201606070 issue 120 pp. 1067 – 1092 30.06.2016 ru 492
Particle dynamics in metrics with logarithmic potential The work considers the problem of modeling the motion of particles in a unified field theory to 6D, in theory, supergravity in the 112D and metric galaxies. We have investigated a centrally symmetric metric in the 112-dimensional Riemannian space, which depends on the radial coordinate, time, and 110 angles. We present a system of equations describing the angular movement on a hypersphere of any dimension N. It is shown that the motion on the hypersphere depends on the 2 (N-1) of singular points. We have installed general nature of relativistic motion on a hypersphere when it is displayed on the plane and in three-dimensional space. It is shown that the motion determined by the reflection from the singular points that of motion on the plane in some cases leads to thickening of the trajectories in the neighborhood of sides of the rectangle. The 6D investigated metric describing the case of motion with two centers of symmetry. It is shown that in such a metric exists a class of exact solutions, logarithmically dependent on the gravity centers of origin. It is found that in this system there is a motion with condensation paths around the sides of the rectangle, due to scattering of test particles gravity sources. We set the general nature of angular motion on a hypersphere and radial movements in 6D in the metric of a logarithmic potential. It is proved that similar solutions with logarithmic potential exist in galaxies metric in the metric of Einstein's theory of gravity. The article also describes the connection of the solutions to the nonlinear electrodynamics, and with a theory of quark interactions and Yang-Mills theory
555 kb

COLOR MATTER GENERATION IN THE RICCI FLOW IN GENERAL RELATIVITY

abstract 1221608082 issue 122 pp. 1232 – 1256 31.10.2016 ru 493
In this article, we investigate the restricted problem of many bodies with a logarithmic potential in the general theory of relativity. We consider the metric having axial symmetry and containing a logarithmic singularity. In numerical calculations, we studied the properties of the gravitational potential in the problem of establishing a static condition in which multiple singularities retain the initial position on the axis of the system. This is achieved due to relativistic effects, which have no analogues in Newton's theory of gravitation. The motion of relativistic particles in a logarithmic potential sources distributed on the surface of a torus simulated. It is shown that the trajectory of the particles in these systems form a torus covered with needles. It was found, that the Ricci flow in the general theory of relativity could be born three kinds of matter - positive and negative energy density, as well as the color of matter, the gravitational potential of which is complex. It has been shown that this type of material is associated with the manifestation of the quantummechanical properties, which is consistent with the hypothesis of the origin of Schrodinger quantum mechanics. It is assumed that the most likely candidate for the role of the color of matter is the system of quarks as to describe the dynamics of quarks using the logarithmic potential, and the quarks themselves are not observed in the free state
573 kb

MATTER GENERATION FROM SINGULARITIES COLLIDING IN THE RICCI FLOWS

abstract 1221608069 issue 122 pp. 982 – 1006 31.10.2016 ru 499
In this article, we investigate the problem of creation of matter in the collision of particles, presented by singularities of the gravitational field. A system of nonlinear parabolic equations describing the evolution of the axially symmetric metrics in the Ricci flow derived. A model describing the creation of matter in the collision and merger of the particles in the Ricci flow proposed. It is shown that the theory that describes the Ricci flow in the collision of black holes is consistent with EinsteinInfeld theory, which describes the dynamics of the material particles provided by the singularities of the gravitational field. As an example, we consider the metric having axial symmetry and which contains two singularities simulating particles of finite mass. It is shown that the static metric with two singularities corresponding to in Newton's theory of gravity two particles moving around the center of mass in circular orbits in a non-inertial frame of reference, rotating with a period of two-body system rotation. We have numerically investigated the change of the metric in the collision of particles with subsequent expansion. In numerical experiments, we have determined that the collision of the particles in the Ricci flow leads to the formation of two types of matter with positive and negative energy density, respectively. When moving singularities towards each other in the area between the particles the matter is formed with negative energy density, and in the region behind the particles - with positive density. In the recession of the singularities, the matter with positive energy density is formed in the area between the particles. The question of the nature of baryonic matter in the expanding universe is discussed
830 kb

BAER’S LAW AND EINSTEIN’S VORTEX HYPOTHESES

abstract 1331709048 issue 133 pp. 630 – 652 30.11.2017 ru 499
We consider numerical solutions of the Navier-Stokes equations describing laminar and turbulent flows in channels of various geometries and in the cavity at large Reynolds numbers. An original numerical algorithm for integrating a system of nonlinear partial differential equations is developed, based on the convergence of the sequence of solutions of the Dirichlet problem. Based on this algorithm, a numerical model is created for the fusion of two laminar flows in a T-shaped channel. A new mechanism of meandering is established, which consists in the fact that when the two streams merge, a jet is formed containing the zones of return flow. Vortex motion in a rectangular cavity is studied. It is established that the numerical solution of the problem with discontinuous boundary conditions loses stability at Reynolds number Re> 2340. The trajectories of passive impurity particles in a cylindrical cavity are investigated. An explanation of the behavior of tea leaves in a cup of tea in the formation of a toroidal vortex because of circular stirring is confirmed, which is confirms the wellknown hypothesis of Einstein. A numerical model of flow in an open channel with a bottom incline in a rotating system is developed. It is shown that in both laminar and turbulent flow under certain conditions a secondary vortex flow arises in the channel due to the Coriolis force, which explains the well-known Baer law and confirms the Einstein hypothesis
1876 kb

INVARIANT TO VOLUMES OF DATA, A FUZZY MULTICLASS GENERALIZATION OF F-MEASURE OF PLAUSIBILITY IN VAN RIJSBERGEN MODELS IN ASC-ANALYSIS AND IN THE "EIDOS" SYSTEM

abstract 1261702001 issue 126 pp. 1 – 32 28.02.2017 ru 508
Classic quantitative measure of the reliability of the models: F-measure by van Rijsbergen is based on counting the total number of correctly and incorrectly classified and not classified objects in the training sample. In multiclass classification systems, the facility can simultaneously apply to multiple classes. Accordingly, when the synthesis of the model description is used for formation of generalized images of many of the classes it belongs to. When using the model for classification, it is determined by the degree of similarity or divergence of the object with all classes, and a true-positive decision may be the membership of the object to several classes. The result of this classification may be that the object is not just rightly or wrongly relates or does not relate to different classes, both in the classical F-measure, but rightly or wrongly relates or does not relate to them in varying degrees. However, the classic F-measure does not count the fact that the object may in fact simultaneously belongs to multiple classes (multicrossover) and the fact that the classification result can be obtained with a different degree of similarity-differences of object classes (blurring). In the numerical example, the author states that with true-positive and true-negative decisions, the module similarities-differences of the object classes are much higher than for false-positive and false-negative decisions. It would therefore be rational to the extent that the reliability of the model to take into account not just the fact of true or false positive or negative decisions, but also to take into account the degree of confidence of the classifier in these decisions. In classifying big data we have revealed a large number of false-positive decisions with a low level of similarity, which, however, in total, contribute to reducing the reliability of the model. To overcome this problem, we propose a L2-measure, in which instead of the sum of levels of similarity we use the average similarity by different classifications. Thus, this work offers measures of the reliability of the models, called L1-measure and the L2 measure, mitigating and overcoming the shortcomings of the F-measures; these measures are described mathematically and their application is demonstrated on a simple numerical example. In the intellectual system called "Eidos", which is a software toolkit for the automated system-cognitive analysis (ASC-analysis), we have implemented all these measures of the reliability of the models: F, L1 and L2
432 kb

LOGARITHMIC LAW FOR DYNAMICAL SYSTEMS FROM QUARKS TO GALAXIES

abstract 1201606099 issue 120 pp. 1470 – 1494 30.06.2016 ru 512
The article discusses various examples of dynamical systems in which the motion is determined by the logarithmic law - quark systems, hydrodynamic systems, galaxies. Set the general nature of angular motion on a hypersphere in a space of arbitrary dimension and radial movement 6D in the metric of a logarithmic potential. We investigate the 6D metric describing the case of motion with two centers of symmetry. It is shown that in such a metric exists a class of exact solutions, logarithmically dependent on the gravity center coordinates. It was established that in spiral galaxies the orbital motion is due to the logarithmic potential, which is the exact solution of the field equations of Einstein's theory of gravity. The most well-known and widespread in nature case is turbulent flow over a smooth or rough surface, in which the mean velocity depends logarithmically on the distance from the wall. We derivate the logarithmic velocity profile in turbulent flow from the NavierStokes equations. An analogy of the logarithmic velocity profile and the logarithmic law in the case of erosion of materials under impacts been proposed. In electrodynamics, Ampere's law, which describes the interaction of current-carrying conductors, is a consequence of the logarithmic dependence of the vector potential of the distance from the conductor axis. There is, however, an alternative derivation of Ampere law of the Riemann hypothesis about the currents due to the motion of charges
ßíäåêñ.Ìåòðèêà