Modeling the development of Kelvin-Helmholtz instability in problems of high energy density physics

N.V. Zmitrenko, P.A. Kuchugov, M.E. Ladonkina, V.F. Tishkin

Accepted: 2019-12-01

Abstract

The results of mathematical modeling of the development of Kelvin-Helmholtz 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 CAE-solutions of partial problems of ice navigation. Icebreaker setting and propulsion ability

V.A. Lobanov

Accepted: 2019-11-21

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 shallow-draft 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: 2019-10-22

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. Multi-scale 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 cross-correlation 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, Е.А. Golubchikov, A.V. Pyatlin, A.K. Kuzin, V.A. Kiev, N.N. Shabrov, A.S. Zhuravlev, E.K. Guseva

Accepted: 2019-10-09

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: 2019-10-09

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 fourth-order 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 2-factors of the cubic graph is established. It is shown that the ring sum of all cycles included in the colored 2-factors of the graph is an empty set. The article also addresses the issues of coloring non-planar cubic graphs. The relationship between basic cycles and a rim in a non-planar cubic graph and a ring sum of colored 2-factors 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: 2019-10-06

Abstract

Various types of tomography are widely employed in oil and gas industry for studying inner structure of rocks. Using X-ray or FIB-SEM 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 cross-section; plotting graphs of quality and similarity indices for each layer over the cross-section; 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.

Computer visualization of the identify industrial clusters task using GVMap

E.V. Kozonogova, D.S. Kurushin, J.V. Dubrovskaya

Accepted: 2019-09-01

Abstract

On the basis of systematization ways of reflection the interactions of cluster relations subjects the technique of visualization of identification industrial clusters is presented. As a visualization tool used GVmap, implemented in the software "Graphviz". Identification of clusters at the macro level is based on the symmetric table "input-output" in the context of 86 economic activities. The input parameters were data in the form of a graph and information about clustering in the data. Economic activities are selected as the vertices of the graph. The connections between the vertices of the graph (edge) were constructed on the basis of the matrix of significant supplier-consumer relations obtained by the Maximum method. Clusters of industries are calculated using the method of Zamanski.
Tool GVMap clustered the data displayed geographic-like maps to the image that not only makes it easier to read the graph connectivity of economic sectors, much as you would to shape an adequate development strategy for enterprises to cluster and for the areas of their localization.
To automate the process of industrial clusters identification and their visualization, a software tool in Python was created.
The reported study was funded by RFBR according to the research project № 19-010-00562.

Model, calculation method and visual representation of residual stresses in laser sintering of metal powders

A.V. Koldoba, Yu.A. Poveschenko, M.V. Popov, R.V. Grishaev, F.Kh. Mirzade, V.G. Niziev

Accepted: 2019-08-22

Abstract

One of the key problems of materials science that arises in the technology of laser deposition of powders is the prediction of residual stresses in the product, which are formed as a result of local melting of the material and its subsequent relaxation to the initial temperature, accompanied by non-uniform solidification. A method for investigation of the stress-strain characteristics both in a weld bead and in a substrate due to local heating (above the melting temperature) and subsequent solidification in laser sintering of metal powders is suggested. The model includes two-dimensional stationary equations of thermoelasticity describing the stress-strain state of a non-uniformly heated product, as well as the relations approximating the thermophysical and elastic properties of the used materials in a wide temperature range, including the phase transformation (melting). The computational algorithm developed for the numerical integration of the thermoelasticity equations is based on the support operator method. The algorithm is implemented as a code and visual presentation of the results describing the residual stresses during laser sintering of metal powders for computers with parallel architecture. The joint flat technology was used to obtain the image of the fields of scalar quantities.This was done by filling the vector quantities shown by streamlines with color and the direction field. The spatial distribution of residual thermoelastic stresses in the substrate and in the deposited layer obtained as a result of numerical simulation allows to predict the defects appearing in the product during laser deposition of powders, which depend on the laser treatment mode and on the thermophysical properties of the materials.

Visualization of the variance boundaries for the polarization parameters of light on the Poincare sphere

Accepted: 2019-08-09

Abstract

The methods of parametric information theory are used to study the minimal variance boundaries of polarization parameters estimates of partially polarized quasi-monochromatic radiation in a polarimetric scheme with an analyzer and a phase compensator under conditions of additive-multiplicative normal noise. The density distributions of information on the Stokes parameters in the coordinates of the angle of rotation of the analyzer and the phase shift of the compensator are shown. The analysis of these distributions allows finding the most favorable measurement plans in metrological relation. Matrix variance boundaries of different polarization parameters for the uniform plan and other measurement plans are calculated. The error limits of the estimates of the degree of polarization are calculated. The results of the analysis are confirmed by numerical simulation. The patterns of the distributions of the variance bound estimates of the degree of polarization on the Poincare sphere are given. With the help of the developed technique based on the parametric information theory, it is possible to study estimates of any polarization parameters: azimuth, ellipticity and others. The results of this study can be used to optimize signal processing algorithms and improve the efficiency of optoelectronic devices and systems of a wide profile.

Visualization of the space of technological parameters of ceramic mixture shaping process as an object of bricks production automation

M.A. Nazarov

Accepted: 2019-07-31

Abstract

An approach is proposed to visualize the working area of the technological parameters of the process of shaping the ceramic mixture, carried out in an auger vacuum extruder, in the production of bricks, which is an important element of the analysis of the stage under consideration as object of automation. The vectors of control and disturbing influences, the vector of controlled coordinates, which make up the shear strain rate and the moisture content of the ceramic mixture in the pressure head, the amount of vacuum in the vacuum chamber of the auger extruder are determined. The well-known experimental data on the influence of the elements of the vector of controlled coordinates on the strength of the finished ceramic brick, and, therefore, in accordance with GOST 530 2012 on its mark, have been studied. Evaluation of these dependencies and a number of transformations and manipulations allowed us to represent the sought space of technological parameters of the shaping process in the form of a structural diagram, which is convenient to use when conducting computational experiments, and in the form of a three-dimensional graphic design, the analysis of which allows us to determine the optimum operating modes of an auger vacuum extruder in brick production required brand.

Computer visualization in the course "Abstract algebra"

V.I. Varankina, E.N. Lubyagina, R.V. Markov, A.A. Petrov, D.V. Shirokov

Accepted: 2019-07-27

Abstract

The work presents the experience of introducing visualization in the teaching of the discipline “Abstract Algebra” to bachelor students specializing in Mathematics. We propose to apply visualization elements at different stages of training: in presenting theoretical information, in solving practical problems, in the process of control and self-control. The article gives an example of using the GeoGebra system to create visualization components. Here we propose the option of introducing the created objects into educational presentations with the help of LaTex computer imposition system. We used Javascript and PHP programming languages, MySQL databases, and the APACHE WEB server to create a course site and to incorporate interactive elements into it.

The research of the stereoscopic characteristics of virtual reality helmets

A.I. Vinokur, N.V. Kondratiev, Yu.N. Ovechkis

Accepted: 2019-07-27

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 high-quality 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 three-dimensional 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 three-dimensional 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.

Memory-effective methods and algorithms of shader visualization of digital core material model

M.V. Mikhaylyuk, P.Yu. Timokhin

Accepted: 2019-07-12

Abstract

The paper deals with the task of real-time visualization of digital core material model (DCM) obtained by X-ray computed tomography. Novel approach, effective methods and algorithms for visualization of large allocated volume of DCM are proposed, which are based on high-performance programmable tessellation capability of commodity graphics cards with a multicore graphics processing unit (GPU). The methods provide an effective video memory usage and a high visualization rate for the ranges of absorption coefficient, corresponding to pore space or mineral skeleton of the core material. The solution proposed is based on visualization of trihedral polygonal models of visible voxels and on the original system for constructing such models on GPU by means of tessellation shaders developed. Based on these methods and algorithms, a program module is developed, which implements 3D visualization of the allocated volume of DCM and the construction of porosity plot. The program module was tested on the DCMs of Bazhenov formation and sandstone, that confirmed adequateness of developed solution to the task arisen.

Reconstruction of interference and Hilbert structures from numerical models of the isotherm field in convective currents induced in a vertical layer of water by unsteady boundary conditions

V.A. Arbuzov, E.V. Arbuzov, V.S. Berdnikov, Yu.N. Dubnishchev, S.A. Kislitsin, O.S. Zolotukhina

Accepted: 2019-07-08

Abstract

The problem of reconstructing interference and Hilbert structures from a numerical model of the evolution of the thermal field of convective flows in a vertical water layer bounded by flat heat-exchanging surfaces under unsteady boundary conditions in the monotonic cooling mode and taking into account density inversion at a temperature of +4 degrees Celsius was solved. The simulation of the thermal fields of convective flows in the form of the dynamic structure of isotherms was carried out taking into account the nonlinear dependence of thermal conductivity and water density on temperature. The field of the phase function, its Hilbert image and the interference field, which are compared with the results of the interference and Hilbert visualization of the fields of phase optical density obtained in the experiment, were reconstructed from the isotherms field supplemented by calculating of the velocity field and of the temperature gradients field. The presented films illustrate the qualitative adequacy of the coevolution of numerical models and real processes.

Fusion of motif co-occurrence matrix and local binary pattern based on intuitionistic fuzzy set for texture classification

C.-P. Yen

Accepted: 2019-07-01

Abstract

Texture classification plays an important role in computer vision and has a wide variety of applications. Based on intuitionistic fuzzy set (IFS) theory, this paper proposes a novel feature descriptor for texture classification by the fusion of motif co-occurrence matrix (MCM) and local binary pattern (LBP), namely IFS-MCMLBP. In this way, IFS is used to model vagueness or uncertainty, and the MCM method for extracting microtexture information, whilst the LBP method plays the role of a global feature. Intensive experiments conducted on many texture benchmarks such as CUReT, Outex, Brodatz and VisTex. The results show that the IFS-MCMLBP method can be remarkably superior to existing texture classification methods such as, LBP, GLCM, LTP, LDiP, LDeP and LTrP.

A novel multiple-windows blending of CT images in red-green-blue (RGB) color space: Phantoms study

C. Anam, W.S Budi, F. Haryanto, T. Fujibuchi, G. Dougherty

Accepted: 2019-06-19

Abstract

This study develops an algorithm for multiple-windows blending of CT images in red-green-blue (RGB) color space. A CT image is windowed at three different combinations of window width (WW) and window level (WL) values. The first window image is then colorized red (R), the second window image is colorized green (G), and the third window image is colorized blue (B). These three images, representing three combinations of window settings, can then be represented as a single RGB color image. The technique was applied to axial images of TOS-phantom with various objects and anthropomorphic phantom. This multiple-windows blending enables the result of multiple-windows to be presented in a single view without any subsequent changes to the windows settings. This multiple-windows blending is able to visualize many tissues of interest simultaneously with high contrast depending on the initial windows settings. The blending of soft tissue, bone, and lungs windows in thoracic images, for example, produces an image in which the details of soft tissues, bones, and lung nodules can be seen simultaneously in one view. Multiple-windows blending can potentially hasten image interpretation because more information is viewed in a single image. However, this novel method needs the radiologist to adapt to interpreting the new multiple-windows blended image. The method also requires standardization and optimization.

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: 2019-06-07

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 2-30 cm wavelength range, approach the optimum range, which is ~ 0.5-1 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 microwave-recording device based on spin diodes can be promising for an autonomous driving system at conditions of constrained movement with poor visibility and high noise.

Visualization of a business plan

N.N. Krupina

Accepted: 2019-06-05

Abstract

In the investment process, business planning is viewed as the optimization of an organization’s movement towards a strategic development goal in a competitive, risk, uncertainty, and dynamic market environment. The article substantiates the relevance and relevance of a broader and more thoughtful application of visual models in a business plan for successful managerial diagnostics, comprehensive comparison of alternative solutions, increasing the effectiveness of communications and securing partnerships. Visualization helps to make a potential investor not a passive observer of the business plan development process and appraiser of the proposed business idea, but an interested and active person involved in the project discussion, helping to take a fresh look at the company's strengths and weaknesses, threats and opportunities of the environment. The author discusses the information needs of groups of influence on the project, features and information and analytical potential of each element of visual content, the main sections and aspects of the project, as objects of effective visualization, and also provides specific illustrative examples. The effective effect of graphical models is explained from the standpoint of cognitive visualization ideas, when visual information is assigned the role of an important tool not only to gain knowledge, but also to increase the effectiveness of mental operations of comparison, generalization, situational analysis, analogy, choice of actions.

Generating a topological drawing of the flat part of a nonplanar graph

S.V. Kurapov, M.V. Davidovsky, A.V. Tolok

Accepted: 2019-02-01

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.