
Accepted papers
Visualization of the process of neutronphysical calculation of a nuclear reactor
A.O. Bukalin, A.M. Zagrebaev, V.N. Samanchuk
Accepted: 20191216
Abstract
This article describes a computer program for visualization of the process of solving the diffusion equation by the source iteration method. This method is used in the overwhelming majority of software systems for calculation of VVER and RBMK reactors. This program allows you to demonstrate visually the process of obtaining the neutron field micro and macrostructure (macrofield) in the iterative solution of the equation. Visualization of the iterative process allowed us to establish the fact of the rapid appearance of the microstructure of the solution at the first iterations and the slow appearance of the macrofield of the neutron flux density. This fact made it possible to propose a new approach to solving the diffusion equation, namely, to extract the lowfrequency component in the initial data of macroscopic interaction cross sections using digital filtering methods, first to perform the calculation with filtered macroconstants on a coarse grid, and then finally to perform the calculation on a fine grid.
The studies have shown that even on a onedimensional model the calculation of reactor is accelerated several times, which means that when solving a threedimensional problem, the solution speed will increase by two orders of magnitude. This is important when solving optimization problems and «online» calculating emergency situations.
Visualization of the interconnection between dynamics of the system and its basic characteristics
G.V. Kreinin, S.Yu. Misyurin, A.P. Nelubin, N.Yu. Nosova
Accepted: 20191216
Abstract
The paper presents a dimensionless mathematical model of the dynamics of the drive complex and the visualization of the solution of this model, which allows to obtain comparative estimates (characteristics) of the solutions obtained in the first approximation.
The authors proposed an original control system for the drive complex of two hydraulic actuators to lift the load in parallel mode. A distinctive feature is the adopted control circuit of the complex through three hydraulic switchgears, which are responsible for regulating the overall lifting (and/or lowering) speed of the object and maintaining the horizontal position of the object within the specified accuracy in the presence of disturbing factors of different nature. The difference in displacements of the hydraulic actuator rods from some initial (basic) position at a given time is a sign of deviation of the object from the horizontal position. The mathematical model of the object obtained is investigated in dimensionless variables, which greatly simplifies the visual synthesis of the object.
Modeling the development of KelvinHelmholtz instability in problems of high energy density physics
N.V. Zmitrenko, P.A. Kuchugov, M.E. Ladonkina, V.F. Tishkin
Accepted: 20191201
Abstract
The results of mathematical modeling of the development of KelvinHelmholtz instability in the conditions of irradiation of flat targets using an OMEGA laser facility are presented in this work. he vortex growth rate is compared with available experimental data. Taking into account the simplifications made in the numerical formulation of the problem, the various data are in satisfactory agreement with each other. The visualization of the flow made it possible to fully analyze its structure, determine the sizes of the characteristic vortices, and also reveal the differences between the 3D and 2D variants associated with the relaxation of the flow in transverse directions.
Visualization of CAEsolutions of partial problems of ice navigation. Icebreaker setting and propulsion ability
V.A. Lobanov
Accepted: 20191121
Abstract
In article it is emphasized that operation of icebreaking means when ensuring efficiency and safety of ice transport services is distinguished by a wide range of necessary operations, actions, maneuvers, the modes and dynamic working methods. It saves relevant a problem of assessment of their ice performances in special operating conditions. In work using CAE modeling process of the movement in continuous ices, ice cakes and small ice cakes of the multishaft shallowdraft icebreaker ship of the project 1191 in different options of combinations of its draft, a list and a trim is investigated. Qualitative features of influence of setting on the nature of interaction of the vessel with the ice environment are noted. Comparative analysis of experimental data on ice loads on the hull and a propulsion and steering complex is made. Quantitative impact assessments of ship setting on its total ice resistance are given.
Visualization of EEG signal entropy in schizophrenia
I.E. Kutepov, A. V. Krysko, V.V. Dobriyan, T.V. Yakovleva, E.Yu. Krylova, V.A. Krysko
Accepted: 20191022
Abstract
This paper presents the visualization of the study of signal entropy in two groups of subjects. Brain activity signals were obtained using electroencephalogram (EEG). Two groups of adolescents with schizophrenia syndromes and a control group were the objects of the study. For each of the participants in both groups, 16 channels were recorded. Multiscale entropy, model entropy and approximated entropy were analyzed for signal complexity. The results of the entropic assessments were compared in the form of topographic images. Topographic images of the head surface were obtained on the basis of spherical spline. The activity of brain hemispheres for both groups was compared by mean values of crosscorrelation function.
The study showed that visualization of EEG signals can be a useful tool for classification of patients with schizophrenia and control groups. It is suggested that analysis would be useful for psychiatric examination of patients with schizophrenia.
An Application of Big Data Analysis Instruments to the Problem of Visualization of Simulation Results of Gas Dynamics Tasks of Large Sizes
V.I. Reshetnikov, Å.À. Golubchikov, A.V. Pyatlin, A.K. Kuzin, V.A. Kiev, N.N. Shabrov, A.S. Zhuravlev, E.K. Guseva
Accepted: 20191009
Abstract
The article is dedicated to development of the software environment for interactive visualization of simulation results of gas dynamics problems on large meshes. Kitware ParaView, which is popular software among engineers and scientists, is selected as a graphical frontend. Within the framework of the project, an interaction between client and server ParaView programs is used. The key feature of the work is the usage of Apache Hadoop and Apache Spark systems for distributed input of simulation results from files on hard disk. The results are stored on the cluster in file system Hadoop Distributed File System (HDFS) under control of Apache Hadoop and are provided to ParaView server by means of data processing tool Apache Spark.
Algebraic methods for coloring cubic graphs
S.V. Kurapov, M.V. Davidovsky, A.V. Tolok
Accepted: 20191009
Abstract
This article considers algebraic methods for coloring cubic graphs based on the results of the Tate theorem. To formally describe the coloring of a cubic graph, the authors use a fourthorder Klein group transform. For the transition to the coloring of the graph, the edges of the basis cycles are respectively colored. Overall, the mathematical framework for describing topological graphs is described in the article. Based on the coloring of the edges, the formation of colored disks and the mathematical description of the operation of rotating colored disks with subsequent recoloring of the edges are considered. It is shown that the operation of rotating color disks can be presented as a ring sum (addition modulo 2) of cycles. For an unambiguous description of the representation of colored disks by means of basic cycles, the concept of embeddability of colored disks is introduced. In the article, the authors provide examples illustrating the application of the operation of colored disks rotation. The relation between the system of induced cycles generated by the rotation of graph vertices and the coloring of 2factors of the cubic graph is established. It is shown that the ring sum of all cycles included in the colored 2factors of the graph is an empty set. The article also addresses the issues of coloring nonplanar cubic graphs. The relationship between basic cycles and a rim in a nonplanar cubic graph and a ring sum of colored 2factors is shown in the article. The relationship between the color rotation of the vertices of a flat cubic graph and the closed Heawood paths is explicitly indicated in the article.
Visualization of quality of 3D tomographic images in construction of digital rock model
A.S. Kornilov, I.A. Reimers, I.V. Safonov, I.V. Yakimchuk
Accepted: 20191006
Abstract
Various types of tomography are widely employed in oil and gas industry for studying inner structure of rocks. Using Xray or FIBSEM tomography, a 3D model of a core sample is constructed for mathematical simulations of fluid flow in porous media and evaluation of physical characteristics of rock. Since images have various defects and distortions, there is a problem of selection of a fragment with the best quality from the initial 3D image. At the moment this operation is made manually on the basis of an expert’s personal opinion and takes significant time. In this paper, we investigate applicability of existing referenceless quality metrics for evaluation of tomographic images and propose the approach for visualization of spatial change of 3D image quality. The method includes the construction of central crosssection; plotting graphs of quality and similarity indices for each layer over the crosssection; generation of combined heat map of quality of cubic fragments with various size. The proposed approach significantly accelerates and makes less subjective selection of the best region for further simulations in digital rock workflow. The choice of colour scale is considered to facilitate the analysis of graphical information for people with colour vision deficiency.
The research of the stereoscopic characteristics of virtual reality helmets
A.I. Vinokur, N.V. Kondratiev, Yu.N. Ovechkis
Accepted: 20190727
Abstract
Individual stereoscopic virtual reality devices have become very popular all over the world. Their advantages in comparison with traditional means of presenting stereo images are to provide a large viewing angle, taking into account the location and movement of the observer, binding the image to the direction of his gaze. To obtain a highquality and comfortable visualization system, it is necessary to achieve a certain ratio of technical parameters. In this paper, we consider the limitations of the depth of a threedimensional image reproduced in helmets of virtual and augmented reality, due to the stereoscopic nature of its formation. Methods and results of the estimated calculations of the boundary distances for different conditions for the demonstration of threedimensional stereoscopic images are given. Experimental studies of the overall parameters of optical circuits of seven different types of virtual reality helmets have been carried out. It is shown that most of them, especially the most accessible as cheaper and often used in a social environment, are not suitable for demonstrating deep scenes of the surrounding visual environment. Recommendations for their modernization are given.
Spin Diode Based Microwave Registration and Holographic Visualization of Wave Front Scattering for an Autonomous Driving System
K.A. Zvezdin, D.R. Leshchiner, A.F. Popkov, P.N. Skirdkov, A.G. Buzdakov, G.N. Chepkov
Accepted: 20190607
Abstract
In the paper, we discuss the scheme and the prospects of holographic visualization of scattering objects using microwave registration based on spin diodes to identify obstacles to movement for the car’s autonomous driving system. With wavelength decrease, the resolution of the holographic system grows, but the recording capacity at a given level of irradiating signal and diode noise decreases. We give an algorithm for the numerical reconstruction and visualization of obstacles. Estimates for the resolution and the reliability of object identification, depending on the distance to the obstacle, obtained by numerical modeling. We show that there is an optimal wavelength achieving the maximum range of microwave recording, taking into account the system resolution and the acceptable signal level. Highly sensitive spin diodes, feasible for the 230 cm wavelength range, approach the optimum range, which is ~ 0.51 cm for Schottky diodes, in their holographic visualization ability. Based on the Kotelnikov theorem for the sampling frequency of a harmonic signal, and on numerical experiments, the requirements for the placement density of the receiving elements of the recorder antenna array were determined depending on the distance to the object, the number of sensors and the recording window size. We show that a microwaverecording device based on spin diodes can be promising for an autonomous driving system at conditions of constrained movement with poor visibility and high noise.
Generating a topological drawing of the flat part of a nonplanar graph
S.V. Kurapov, M.V. Davidovsky, A.V. Tolok
Accepted: 20190201
Abstract
In this paper, we consider the issues of the diakoptic approach to constructing a topological drawing of the flat part of a nonplanar graph. It is shown that the first stage of constructing a topological drawing is based on the matroid properties of the set of graph isometric cycles. The authors propose a method for constructing a topological drawing of the flat part of a nonplanar graph using the methods of structure numbers algebra. The initial information for the solution is based on the set of graph isometric cycles, which makes it possible to reduce the solution to discrete optimization methods. The second stage of joining the cycles is based on the methods of vector algebra of intersections. The necessary mathematical concepts and structures for solving the problem of constructing a flat topological drawing of a nonplanar graph are considered in the paper. The presentation of the stuff is confirmed by illustrative examples.


