bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concretization of nonlinear constitutive relations by results of uniaxial compression and indentation experiments
Authors: Astapov Yu , Markin A , Sokolova M , Khristich D 
Published: May 2021

Abstract
A method for the experimental specification of the variant of the Hencky–Murnaghan constitutive relations is proposed. A series of compression and indentation experiments of a number of specimens made of highly elastic materials is carried out on the experimental stand. An iterative procedure for determining constants from experiments on inhomogeneous deformation is developed. The convergence of the iterative process is investigated. The values of the constants of the Hencky–Murnaghan model are found for materials of two types. It is found that the Hencky–Murnaghan model describes the results of indentation experiments on a wider range of deformations than the Hencky model.
To the question of calculation of amendments to the Navier – Stokes equation
Authors: Gladkov S O , Aung Zaw 
Published: May 2021

Abstract
In the paper provides a detailed conclusion of the Navier-Stokes equation using the classic Boltzmann equation to the third order in the free length path of the molecules. It is noted that the biharmonic component of the Laplace’s operator will play an important role in the research of wrap flow of fluid of nanoparticles.
Some exact solutions of the heat conduction equation in parallelepiped obtained by the fast expansions method
Authors: Goryainov V V , Kuznetsov S F , Nikiforova O Yu , Voronkova I S 
Published: May 2021

Abstract
An analytical solution to the boundary value problem for the Poisson equation in a parallelepiped was obtained in general form using the fast expansions method. The construction of exact solutions of the heat conduction equation for the cases of an internal source depending on coordinates was shown in the work. The study of the influence of the variability of the internal source on the propagation of heat in the body at the same initial temperatures at the parallelepiped vertices was carried out. In this case, the heat in the body will be transferred only in those directions in which the internal source is changed.
About one-dimensional inhomogeneity of elastic characteristics of materials
Authors: Gotsev D V , Kovalev A V , Sporykhin A N , Shashkin A I 
Published: May 2021

Abstract
The analysis of existing methods for modeling the elastic characteristics of materials is carried out. It is taken into account the one-dimensional continuous inhomogeneity of the elastic characteristics. In contrast to the known monotone functional dependencies that describe the distribution of mechanical characteristics of elastic bodies along one direction, we propose models for describing inhomogeneous elastic properties of materials that are non-monotonically distributed along one coordinate. An approximate analytical solution of the Lame problem is obtained for a specific non-monotonic distribution of the displacement modulus along the radial coordinate. The solution is obtained in the form of a convergent sequence of approximations. A numerical experiment is performed for specific values of the approximating coefficients and the results are analyzed.
Theory of thin shells as a spatial two-dimensional continuum in an oblique system of coordinates
Authors: Kozlov Vladimir A , Kashirina Darya A 
Published: May 2021

Abstract
In contrast to the known approaches in the theory of shells, based on certain assumptions, and the traditional reduction of a three-dimensional problem to a two-dimensional one, in this paper, static and geometric relations are obtained from the position of the interaction of linear forces and moments in a spatially curved two-dimensional continuum. This approach was applied by E. Reissner, but in an orthogonal grid and for physical components. Relations are presented in tensor, vector, and scalar forms.
Nonlocal dynamic temperature stress simulation
Authors: Kuvyrkin G N , Savelyeva I Yu , Kuvshinnikova D A 
Published: May 2021

Abstract
The development of technologies for obtaining consolidated structural materials has increased interest in modelling materials with a heterogeneous structure. For models of such materials, an important factor is the relationship between the characteristics of the micro-(nano- ) level and the laws of continuum mechanics at the macro level. The widespread use of modern structure-sensitive materials in extreme conditions is the reason for the urgency of the problem of developing methods of mathematical modelling that allow describing such materials. New nonlinear dynamic problems that arise in this case require a new approach to the study and prediction of the mechanical behavior of such materials under conditions of high-intensity external influences. The paper considers a nonlocal model of dynamic temperature stresses. The model is based on the methods of globalized continuum mechanics. The basic equations of the model are derived from conservation laws. The model of thermomechanical processes in a nonlocal medium includes integro-differential equations with various boundary conditions. Equations describe stress in structural members. Also, the paper proposes an algorithm based on the finite element method to solve the problem. The distributions of temperature stresses in the nonlocal layer of the material are obtained and the influence of the main parameters of nonlocality on the solution of the problem is analyzed.
Examples of controlling the technological stress state characteristics of layer-by-layer manufactured products in the framework of the accreted solid model
Authors: Parshin D A 
Published: May 2021

Abstract
A mathematical model of quasi-statics of accreted deformable solids is proposed for the mechanical analysis of technological processes of slow multilayer power winding of a thin sheet onto the outer side surface of a sufficiently rigid circular mould made in advance. By using the analytical dependences obtained in the framework of this model, two problems of different type on the technological control of the characteristics of the formed product stress state developing during the winding process are formulated and analytically solved. In these problems, setting appropriate programs for changing in course of this process the thickness of the wound sheet and the tension force applied to it is used as the controlling impact.
The method of boundary states with perturbations as applied to the analysis of geometrically non-linear elastostatic bodies
Authors: Penkov V B , Levina L V , Novikov E A , Nazarov S Yu 
Published: May 2021

Abstract
This study makes a case for the application of the numeric and analytic method of boundary states with perturbations (MBSP) to analytic problems focused on the stress-strain states (SSS) of geometrically non-linear isotropic elastic bodies. The defining relations are represented through a weakly non-linear operator equation that contains (on an additive basis) a non-linear operator decomposable into a linear combination of a sequence of linear operators. A solution is proposed for a simple case of a linearly heterogeneous uniaxial loading problem for a long half-pipe with butt ends subjected to loads. Even in this load scenario, geometrical non-linearity affects the way the body alters its shape and causes buckling. This study analyzes the SSS involved, draws conclusions, and addresses application prospects.
High accurate sine and cosine interpolation with repeated differentiation ability obtained by fast expansions technique
Authors: Chernyshov A D , Popov M I , Litvinov D A 
Published: May 2021

Abstract
Fast trigonometric interpolations on a finite interval with different basis functions and increased accuracy are provided. Sine interpolation exactly coincides with this function at the interpolation points, and derivatives of cosine interpolation of the second example exactly coincide with derivatives of the said function at the interpolation points. In all cases interpolations allow differentiation for a given number of times being equal to the order of a certain boundary function. The applied Fourier series converge quickly and hence they can be limited to a small number of terms, thus greatly saving computing time. These special features allow their use in solving complex applied multi-dimensional problems of integro-differential type. The compact formulas for trigonometric interpolations in an explicit form are given which facilitate their application. An error estimate is provided and, algorithms for applying the described interpolations are setup.
Possibilities for predicting the state of usability web resources
Authors: Astachova I F , Makoviy K A , Khitskova Yu V 
Published: May 2021

Abstract
The article discusses the possibilities of predicting the state of the web resources usability. The usability testing procedure is quite costly from both financial and time points of view. Therefore, a system that reduces these costs is useful for modern organizations. Different approaches of forecasting the number of visitors: ARIMA model and Neural Networks are considered. An important time series property for ARIMA model being applicable is the stationarity of the series. It is shown that this model is not suitable enough for the investigated time series, some types of neural networks are also not suitable for various reasons. As a result, NARX networks are selected, which are successfully used for time series forecasting, providing an opportunity to use an exogenous variable.
Spectral analysis of one class perturbed first order differential operators
Authors: Garkavenko G , Uskova N 
Published: May 2021

Abstract
We use the method of similar operators to study a mixed problem for a first order differential equation with a fractional integration operator. The differential operator defined by the equation is transformed into a similar operator that is an orthogonal direct sum of finite-rank operators. The estimates of eigenvalues, eigenvectors are obtained. The result is used to construct an operator group.
On one physical interpretation of generalized conditions Cauchy-Riemann
Authors: Gladyshev Yu A , Loshkareva E A 
Published: May 2021

Abstract
The message shows that in variables, the generalized Cauchy-Riemann conditions (CRC) coincide with the Maxwell system for the electromagnetic field, and the possible existence of magnetic charges and currents is assumed. This makes it possible to give a physical interpretation to all 8 components of the solution of generalized СRС. When the generalized СRС is taken as a basis, two scalar fields necessarily appear. They are interpreted as some fields of spatially distributed electric and magnetic charges and currents. The introduction of the attached generalized СRC allows us to give a method for determining the potentials of the electromagnetic field under the assumptions made and to determine the gauge transformations more General than the well-known ones. Of course, having made certain restrictions, all the results coincide with those accepted in classical electrodynamics. The author points out that he does not make any physical statements and all constructions are purely mathematical in nature.
Stability of differential-difference parabolic system with distributed parameters on the graph
Authors: Provotorov V V , Zhabko A P 
Published: May 2021

Abstract
The work presents the results of the analysis of the approximation of a differential system with distributed parameters on the network domain. This approximation consider in a space of summable functions with a compact bearer on network domain. The question is whether the differential system retains its main properties when its approximation – uniqueness weak solvability, continuity according to the input data, stability on Lyapunov and in what cases (under what conditions) it is possible to replace the analysis of the differential system by analysis of its differential-difference analogue. The study uses a simplified bearer of functions – graph, which is a private case of a network domain (the graph’s edges are parameterized by a one-dimensional spatial variable that changes on the graph). On the set of these functions study the differential-difference equation. This simplification only frees us from the unnecessary routine technical work, where the function bearer is an arbitrary the network domain of multi-dimensional Euclidean space, but as it does not affect on the transfer of ideas and results presented in the work to this multidimensional event. The transition from a differential system to a differential-difference analogue (differential-different system) is carried out using the method of finite difference on the time variable (Rote semi-digitization method). The conditions of weak uniquely solvability of differential-difference system and continuity of the input data are presented. guaranteeing the stability of a weak solution of differential-differential system. These conditions guarantee the stability of a weak solution of differential-difference system.
Experimental studies of the process of initiation and spread of the dangerous fire factors while burning of the tube stock in the tunnel
Authors: Aqeev P M , Sysoeva T P , Kukharev A A , Sobolev P M , Yakhontova O N 
Published: May 2021

Abstract
The present article is concerned with the analysis of the experimental results performed with full-size large-scale prototypes of tube stock in subways in case of the fire in the tunnel. The process of the fire spread in the passenger compartment and along the tube stock is investigated.
Distributed computing systems synchronization modeling for solving machine learning tasks
Authors: Azarnova T V , Polukhin P V 
Published: May 2021

Abstract
Distributed computing systems are an effective tool for solving complex problems related to processing large amounts of information and data, in particular, machine learning tasks. To improve the efficiency of these systems in solving complex tasks, special methods for synchronization processes modeling, evaluating and predicting processing delays and query execution, developed in the terms of this models. The approaches for the distributed computing systems organization based on the mathematical apparatus of queuing theory, considered in this paper, allow optimizing the requests processing mechanisms related to solving resource allocation problems, and increasing the consistency of computational processes related to machine learning problems.
Assessment of the quality of training of specialists in higher education institutions
Authors: Bezrydin S N , Lupanova A V , Kalach E V 
Published: May 2021

Abstract
The article presents the requirements and various ways to assess the quality of educational services and training of specialists in higher education institutions, and also offers a “comprehensive” indicator of the quality of management systems that takes into account the main results of educational activities of the University – the degree of development of educational programs by students and satisfaction of the main consumers of educational services.
Development of an information and analytical system for presenting data on the refractive properties of the environment
Authors: Bobrov V N , Dushkin A V , Sitnikov A I , Sushko E A 
Published: May 2021

Abstract
The article proposes a variant of constructing an information and analytical system that makes it possible to control the refractive properties of the environment (atmosphere) based on the actual values of its parameters, as well as to determine the numerical values of the refractive index of the atmosphere. Its operation is based on a method that makes it possible to detect errors during measurements by optical systems in a real atmosphere. The main feature of the method under consideration is the comparison of the refractive indices in a real and ideal atmosphere. The difference in the corresponding values of the refractive index of the atmosphere makes it possible to correct the results obtained during measurements by optical systems. This article describes the operation of the software algorithm, which allows not only measuring and evaluating based on information on hydrometeorological parameters and refractive properties of the surface layer of the atmosphere, but also visualizing the results of measurements carried out by optical systems. Experimental studies carried out confirm the high adequacy of the models underlying the described complex.
Construction of a dual attractor for linear randomized systems of iterated functions
Authors: Bukhovets A , Moskalev P , Biryuchinskaya T 
Published: May 2021

Abstract
The Legendre transform is applied to the attractors of linear randomized systems of iterated functions X
1 and X
2, construction using the ordered (F1) and disordered (F2) algorithms. The original attractors X
1 and X
2 have identical similarity dimension d

S
(X
1) = d

S
(X
2), but applying the Legendre transform to X
1 generates a set

X

1

*

with a linearly ordered structure and similarity dimension

1
<

d

S

(

X

1

∗

)

<

d

S

(

X

1

)

, and applying the Legendre transform to X
2 generates a set

X

2

*

with a disordered structure and similarity dimension

d

S

(

X

2

)

<

d

S

(

X

2

∗

)

<
2

.
Optimal deployment and principles of tracing for the distributing lines of pumping plants in the mountain terrain
Authors: Dmitriev E V , Kalach A V , Mokrozub V G , Cherepanov E A 
Published: May 2021

Abstract
In this paper, we propose new graphical algorithms for planning and optimal placement of pumps for outdoor fire extinguishing networks and propose mathematical optimization models for constructing various outdoor fire water supply networks for microdistricts located in mountainous areas (with significant elevation differences). The solution was carried out by constructing Fermat-Torricelli-Steiner points for the optimization problem of constructing a spatial dead-end network in three-dimensional space.
Integration of decoupling capacitors in the structure of controlled metamaterial
Authors: Ishchenko E A , Pasternak Yu G , Pendyurin V A , Fedorov S M 
Published: May 2021

Abstract
The article studies a metamaterial placed in the aperture of a rectangular waveguide with dimensions of 36x18.1 mm to change the phase of the transmitted wave depending on the switched pin diodes. Since pin diodes are switched by supplying a constant voltage to them in the metamaterial structure, capacitors with a capacitance of 35 nF were installed, which make it possible to achieve separation of the constant component of the switching voltage from the alternating one, and, accordingly, ensure switching only in the required nodes. The simulation results contain S-parameters of the system, which prove the possibility of using the proposed metamaterial as a waveguide phase shifter.
On some problems of modelling the non-stationary heat conductivity process in an axisymmetric multilayer medium
Authors: Kalmanovich V V , Kartanov A A , Stepovich M A 
Published: May 2021

Abstract
Some possibilities of solving the non-stationary heat equation in an axisymmetric multilayer medium are considered. The problem is solved by combining Fourier method and the matrix method. The solutions of the first and third boundary value problems are considered. Examples of calculations by the specified method for three-layer and five-layer axisymmetric systems are given.
On some concepts of nonlinear dynamics suitable for use in linguistics
Authors: Kretov A A , Polovinkina M V , Polovinkin I P , Lometc M V 
Published: May 2021

Abstract
In this paper, we describe hypothetical possibilities for applying nonlinear dynamics methods to linguistic research. We suggest to refer to a large text corpus (meta-book of the writer, national language, language of the branch of knowledge) as a fractal object and to measure its fractal dimension (by Hausdorff). We consider the question of practical calculation of fractal dimension, as well as the question of motivation for applying the fractal concept to the language. In addition, we propose to apply some methods of the qualitative theory of differential equations to modelling the growth of the natural language vocabulary.
Personalized medicine software solutions
Authors: Lavlinskaya O Yu , Kurchenkova T V 
Published: May 2021

Abstract
The article examines the example of the implementation of the telemedicine information system – “Medical information system of accompanying chronic diseases therapy”. Based on the current monitoring of blood pressure, heart rate, and antihypertensive therapy prescribed by the doctor. The concept of developing MIS meets the paradigm of modern medicine, supporting the concept of personification, prediction, prevention, patient involvement in the treatment process based on a positive approach to therapy for patients with hypertension. Formal approaches to automatic correction of therapy based on the method of tree solutions are considered.
Research of the process of functioning of hierarchical multi-level complex organizational systems
Authors: Sumin V I , Smolentceva T E , Zybin D G , Ageev P M , Golovkin R B 
Published: May 2021

Abstract
In the work the process of increase of efficiency in the functioning of hierarchical multi-level complicated organizational systems (HMCOS) is considered and the elements of operation in the considered systems. To solve this problem the tension level of HMCOS operation is involved. Basing on the formulated principles some normative parameters of HMCOS are defined. Validation of the operation process for HMCOS is performed by the normative parameters in the certain moments of time. Considering all of the stages in HMCOS functioning it was made a conclusion that while choosing the normative parameters for the estimates of functioning of the organizational systems in order to get uniform distribution of tension between the staff it seems reasonable to use entropy model.
Application of the information systems in decision-making at the different levels of an enterprise management
Authors: Sumin V I , Zybin D G , Gantz I S , Golovkin R B , Berger E G 
Published: May 2021

Abstract
Specific features of the information support for the process of decision-making while the enterprise management are considered in the work as well as the architecture of the information systems of a certain kind has been developed. The use of the models during making the analysis in the systems of support for decision-making is developed just as the assessment of the capabilities for these systems are validated at the different levels of management. The goals of support at the high level are examined and the possibility of the use of cognitive images is described as the instrument for data visualization.
Implementation of finite element method for solid mechanics problems in Julia programming language
Authors: Antoshkin A D , Cherednichenko A V , Savelyeva I Yu 
Published: May 2021

Abstract
The paper proposes finite element method algorithm implemented in Julia programming language. The main features of Julia programming language are described. The results of Kirsch problem solution are presented. Comparing obtained results with appropriate calculations with open-source finite element software Code Aster are also presented.
Solving the diffusion-convection problem using MPI parallel computing technology
Authors: Atayan A M 
Published: May 2021

Abstract
The aim of the work is to build a software package for the distributed solution of the problem of matter transfer in a reservoir. A parallel implementation of the grid domain decomposition methods for computationally complex diffusion-convection problems, taking into account the architecture and parameters of a multiprocessor computing system located on the basis of the infrastructure facility of the University of Science and Technology «Sirius», is considered. An algorithm for parallel solution of the formulated hydrophysics problem using MPI technology has been developed. The analysis of the efficiency of the developed parallel algorithms is carried out and the study of the obtained solutions of computationally complex problems of aquatic ecology is carried out.