bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermodynamic acceleration of two-phase layered flows in channels with permeable walls of MGD-generators
Authors: Kim K K 
Published: December 2021

Abstract
When creating MHD (Magnetohydrodynamic) alternating current generators using liquid-metal working body, the latter is accelerated by piston method, in which the working body is a periodic structure of alternating zones of liquid metal (pistons) and zones of compressed gas, the latter is accelerated liquid-metal pistons. This raises the form stability problem for liquid metal pistons. Viscous frictional forces generated inside the pistons lead to the destruction of the pistons and significantly reduce the efficiency of the MHD unit. One solution is to use gas-permeable walls of the channels of MHD-generators, through the pores of which gas is injected. In this way, the piston flow is isolated from the side surface of the channel by the penetrating gas in the channel cavity. As a result, friction losses are drastically reduced. At the final values of the One solution is to use gas-permeable walls of the channels of MHD-generators, through the pores of which gas is injection coefficients, (? ≥ 0.03)the friction practically disappears. With the channel length determined by the coordinate of the maximum piston speed, 92% of the current marginal efficiency values can be achieved. The maximum efficiency of the runaway channel can be achieved by selecting the optimal value of the air injection coefficient. The operation of the devices commutating the injected gas must ensure that there is an injection in an area that is no more than twice the length of the piston.
Problem statement for the analysis of electromechanical systems by simulation modeling methods
Authors: Kim K К , Ivanov S N 
Published: December 2021

Abstract
The article presents an approach to the complex analysis of electromechanical systems using specialized packages of applied simulation programs. It is shown that the choice of research methodology is due to the complexity and mutual influence of energy processes in electromechanical converters and the absence of verified analytical solutions.The main research stages are defined, including the construction of a geometric model of the object, determination of the problem type to be solved and relevant initial and boundary conditions, justification of defining criteria, modeling of electromagnetic, thermal and hydraulic processes and their analysis. The software packages are based on the classical equations of electrodynamics, heat transfer, energy, motion and continuity. Creation of three-dimensional solid parametric model is implemented in the T-FlexCAD system. The simulation experiment was carried out with the use of SolidWorksFlowSimulation system, that allows to process the initial array of design parameters in conditions of the multiphysics problem statement. The variables were ranked using Statistica, a statistical processing and data analysis program. Simulation results of energy exchange processes at varying geometry of defining design parameters allow to establish dependence of electromechanical system output characteristics on design and dimension relations of system elements parameters and to design high-efficiency electromechanical systems on this basis.
The risk-based strategy model technical maintenance of the unique technological structures
Authors: Mironov A , Soldatenko V , Soldatenko T 
Published: December 2021

Abstract
The article considers an approach to the development of a risk-based strategy model for the technical maintenance of a unique technological structure. It is proposed to use the minimum risk of the structure failure as a criterion for optimizing the technical maintenance of the structure. It is shown that this approach allows to decrease considerably and by limited means the risk of the elements failure especially those influencing the structure safety. The task of determining the strategy parameters of technical maintenance of the construction object under consideration is formulated as a Boolean mathematical programming task. The theoretical conclusions are confirmed by the calculation example. The solution showed the advantage concerning the risk of use of the proposed strategy in comparison with the current one.
Acoustic emission control of tensile and compression defects for plastic carbon fiber samples reinforced with side girders
Authors: Stepanova L , Chernova V 
Published: December 2021

Abstract
Tensile and compression tests of composite samples made of carbon fiber reinforced with side girders have been carried out. It was found that the area of active location of acoustic emission (AE) signals corresponds to the destruction of the composite, bolted and glued joints. Destruction of the carbon fiber-reinforced plastic material did not always occur in the area of the fasteners, but the sources of AE signals with the maximum total amplitude were registered in the destruction zones.
Modeling the convective thermal heat transfer of nanofluids with carbon nanotubes in cylindrical minichannel
Authors: Rudyak V , Minakov A , Guzey D 
Published: December 2021

Abstract
This paper is devoted to the development of an algorithm for numerical modeling convective thermal heat transfer of nanofluids with carbon nanotubes. The algorithm is based on a one-liquid description of a nanofluid with common macroscopic variables. The properties of the nanofluid are determined only by the concentration of carbon tubes, and it is assumed that their distribution is uniform and does not change during the flow. A nanofluid can have both Newtonian and non-Newtonian rheology. The fundamental point of this algorithm is the need to use real thermophysical data in solving specific problems, which depend on the concentration of carbon nanotubes naturally. The transport equations are solved using finite volume method. The algorithm was tested by comparing the simulation data with the experimental. The problem of convective thermal exchange of nanofluid with single-walled nanotubes is solved. The corresponding experimental data were previously obtained by the authors of this work. It is shown that the algorithm simulates the considered flow with high accuracy. In addition, its important advantage is the possibility of modeling the flow characteristics, which cannot be measured experimentally. As such example the data on the velocity and temperature profiles of the fluid in the channel are presented.
Theoretical background for simulation of physical processes in the interfacial layer “solid-liquid”
Authors: Ignatyev A A , Gotovtsev V M , Gerasimov D V , Provatorova G V 
Published: December 2021

Abstract
The paper shows a modification of the quasi-thermodynamic approach to simulation of the interfacial layer from conditions of its mechanical equilibrium. The anisotropy of the interfacial stress tensor is represented as the sum of the ball and deviator parts, where the ball part defines the pressure in the medium and the deviator part forms the components responsible for the liquid surface tension. Obtaining a closed system of equilibrium equations was possible taking into account evaporation from free surface of liquid. The result is a simple expression for determining the thickness of the interfacial layer.
Study of the working process of a diesel engine with modified fuel
Authors: Yur G , Nosonova E 
Published: December 2021

Abstract
The research objective is to reduce specific fuel consumption and emissions of exhaust fume pollutants. Specifically treated (modified) fuel is used to comprehensively improve the economic and environmental performance of the diesel operation process. Fuel treatment was carried out at a pilot plant using the process of fuel gas cavitation. During processing, high-molecular fuel compounds were broken down and the fuel was saturated with gas-vapor bubbles. The description of the pilot unit is given. The characteristics of the base distillate and modified fuel are studied. A mathematical model and the numerical study results of the fuel droplet development containing vapor-gas bubbles are presented. An experimental study of the work process in a 10.5/12 H diesel engine single-cylinder compartment when operating on various fuels was carried out. Diesel tests have shown that when using modified fuel, the specific indicative fuel consumption has decreased by 5-7 per g / kWh, the exhaust gas temperature has decreased by 5-8 degrees, the concentration of nitrogen oxides in the exhaust fumes has decreased by 32-46 ppm, the concentration of total hydrocarbons has decreased by 9-14 ppm, the smoke content has decreased by 1.2-1.7 times.
Airborne noise calculation for single-layer partitions with the concentrated parameters method
Authors: Zakharov A V , Saltykov I P 
Published: December 2021

Abstract
The article considers an approach to the calculation of sound insulation for building partitions with the method of concentrated parameters at the standard frequency range, which is specified in regulatory documents. The concepts of “reduced” and “concentrated” masses are introduced for objects that are sound conductors. It is noted that the physical model of sound insulation in the three conditionally allocated frequency ranges of the standard spectrum has differences. The calculated equations of sound insulation for three frequency ranges are given. Systems of equations for obtaining the calculation formulas at the first and the second frequency ranges are used. The systems consist of equations for the conservation of the amount of motion and the conservation of kinetic energy. The influence of the damping effect of air and resonant phenomena in the plate on the final value of sound insulation is described. The nature of sound propagation in the third frequency range is considered, in which, unlike the first two sections of the frequency spectrum, where the propagation of flexural waves is mainly recorded in the plate, shear and dilatational vibrations have a predominant influence on the sound insulation level. Examples of graphs for massive partitions obtained by the considered method are given. The accuracy of the proposed method is evaluated in comparison with the normative code’s method and the method based on the theory of self-matching of sound fields. A general algorithm for calculating sound insulation in the entire standard frequency range is presented.
Modification of Anshel-Anshel-Goldfeld Postquantum Algorithm / Protocol Based on Algebraic Braid Groups, in Order to the Span–Cyberattack Neutralization
Authors: Baev D A , Cherckesova L V , Safaryan O A , Kravchenko V O , Razumov P V 
Published: December 2021

Abstract
This article deals with relatively young field of cryptography, namely cryptography based on the theory of infinite abstract groups. The research identifies the main problems on which this type of cryptography is based, and the cryptoanalysis conducts of one of the algorithms grounded on the problem of mating (conjugate) element finding, on the base of which the protocol for common key generating is developed. As the algorithm under study, the protocol for generating the common key based on Anshel-Anshel-Goldfeld algorithm, built on the algebraic braid groups, is investigated. During the study of this protocol, one of possible cyberattacks was identified, which allows to get hold of the secret keys of subscribers. To eliminate and to neutralize this span–cyberattack, the new modification of Anshel–Anshel– Goldfeld (AAG) algorithm was developed, which significantly reduces the probability of this cyberattack successful implementation. Analysis of this modification operating time was carried out also.
Solution of boundary value problems with moving boundaries by using an approximate method for constructing solutions of integro – differential equations
Authors: Litvinov V L , Tarakanov A V 
Published: December 2021

Abstract
The problem of oscillations of objects with moving boundaries, formulated as a differential equation with boundary and initial conditions, is a non-classical generalization of a problem of hyperbolic type. To facilitate the construction of a solution to this problem and justify the choice of a solution form, equivalent integro-differential equations are constructed with symmetric and time-dependent kernels and integration limits varying in time. The method for constructing solutions of integro-differential equations is based on the direct integration of differential equations in combination with the standard replacement of the desired function with a new variable. The method is extended to a wider class of model boundary value problems that take into account the bending stiffness of an oscillating object, the resistance of the environment, and the rigidity of the substrate. Particular attention is paid to the consideration of the most common in practice case when external disturbances act at the boundaries. The solution is made in dimensionless variables accurate to second-order values of smallness with respect to small parameters characterizing the speed of the border.
Automatic segmentation of the borders of the pathological focus in the macular area of the retina to calculate the area of the pathological focus
Authors: Filippenko V A , Bondarenko U F , Dolgov V V , Epikhin A N 
Published: December 2021

Abstract
Optical coherence tomography (OCT) is a modern, non-contact method of diagnostic examination that enables the visualization of various tissues of the human eye in a cross-sectional view at the microscopic level with the required morphological information. The software pre-installed in such devices contains many different tools for analyzing scans and has almost all the functionality necessary for the doctor to make a correct diagnosis. However, as time passes, more and more advanced methods of analyzing the images appear, which actualizes new tasks of developing additional software that can supplement and expand the functionality of the diagnostic equipment. This paper proposes an algorithm for automatic segmentation of the borders of a pathological focus in the macular area of the retina to calculate the area of the pathological focus, which together with other algorithms for analysis of morphometric parameters of the human eye, which are still under development, will be used for more accurate diagnosis of the stage of age-related macular degeneration.
Deanonymization of users based on correlation analysis
Authors: Boldyrikhin N V , Altunin F A , Svizhenko A A , Sosnovsky I A , Yengibaryan I A 
Published: December 2021

Abstract
The article discusses the issues of deanonymization of network users who hide their data in order to evade responsibility when committing malicious acts. Within the framework of this work, a user deanonymization algorithm has been developed based on traffic correlation analysis. The algorithm is based on comparing the statistical characteristics of traffic generated by an unknown user with the characteristics of traffic corresponding to known users. An illustrative example of the implementation of the algorithm, which confirms its effectiveness, is given.
Wavelet filtering for solving the problem of selecting the outlines and analysis of the measurement results in the background of noise
Authors: Shvidchenko S , Zhukovskiy A , Tkachuk E 
Published: December 2021

Abstract
Currently, the issue of developing new modern algorithms and methods is quite relevant, which will allow in an automated mode to analyze images (signals and the results of their measurements) against a background of noise. This task is relevant in the analysis and modeling of dynamic processes and objects, in the search for methods for automating their control. For the process of automating the processing of the results of computational experiments, it is important to implement the calculation of the derivatives of the first and second order against the background of noise.
Promising directions for the development of modern databases
Authors: Kalayda Alexey V 
Published: December 2021

Abstract
In this article, we will compare the SQL and NoSQL models, their advantages and disadvantages, clarify the variations of using both approaches to database management and explain in which cases it is better to use one or the other model. Three main characteristics of the system were tested: parallel data processing, working with information stores, and data replication. The possibility of parallel data processing was evaluated by analyzing the mechanisms of blocking, multi-level parallel access control and ACID. Storage testing covered both physical media and RAM usage. Replication was tested in synchronous and asynchronous modes. During the tests, we found out that SQL databases with the possibility of clustering showed promising performance results per node and also have scalability.
Intellectualisation of the decision support system by a multiagent robotic system based on neural network technology
Authors: Ivanov S V , Kotelnitskaya L I , Khorolsky E M 
Published: December 2021

Abstract
The article considers the process of forming management decisions for the correct operation of a multi-agent robotic system (grouping of unmanned aerial vehicles (UAVs)) in a rapidly changing conditions. A neural network (NN) is used as a regulator, which is a perceptron with two intermediate layers, one is input and the other one is output. The training of the constructed neural network is carried out according to an algorithm that combines the ideas of the conjugate gradient method with quasi-Newtonian methods, and in particular, uses the approach implemented in the Levenberg-Marquardt algorithm. As input parameters for building a control system, various types of situations are used in which the UAV leader has to make decisions. Such initial data are a three-dimensional data structure, which is a two-dimensional array, each element of which is a vector. One vector reflects all available information about the situation in certain geographic coordinates (weather conditions, data on other damaging factors affecting the ability of the UAV to operate in a certain area), and the other describes the current state of the UAV (power reserve, weight, operability of components and assemblies, term of next service, etc.). The obtained information is put down into the input layer of the NN by numerical equivalents. The paper proposes a situational work model of a UAV group in special conditions.
Mathematical experiment as a tool for modeling the freight transportation process
Authors: Bogachev V A , Kravets A S , Bogachev T V 
Published: December 2021

Abstract
The process of multimodal freight transportation on a railway loop is investigated, for which a multicriteria optimization model with time indicators is created, which is a nonlinear integer programming problem. The developed approach is based on egalitarian and utilitarian principles in the welfare theory and allows (along with Pareto optimal transportation plans) to find other plans that can be considered rational from the point of view of maintaining the balance of interests of the transportation process participants. A mathematical experiment is an effective heuristic tool in research. The algorithm for solving the optimization problem is implemented in the environment of a computer algebra system and brought to numerical results.
Method for assessing the operating quality of a switching node in a technological transmission network data in the context of DDoS attacks by an intruder
Authors: Privalov A A , Lukicheva V L , Tsvetkov D N , Titov S S 
Published: December 2021

Abstract
The purpose of this study is to develop a mechanism to account for the effects of a distributed denial of service attack on a switching node, as well as to assess the quality of its functioning under destructive effects. Relevance stems from the possibility of disruption of regional economic complex management due to the impact on the elements of the technological network of data transmission attacker type “distributed denial of service”. Based on the mathematical apparatus of GERT-networks the authors propose an approach to assess the quality of switching nodes. The essence lies in the representation of the data flow service node switching network data transmission under attack by an intruder in the form of a stochastic network, setting the type of partial distributions, the definition of the equivalent function, followed by determining the distribution function delay time packets. The model proposed by the authors allows to evaluate the quality of switching nodes operation under the conditions of “distributed denial of service” intruder attacks, both when transmitting stationary Poisson and self-similar traffic, represented by the Weibull and Pareto flow models. The results obtained are in good agreement with the data given in previously published works. The model allows to analyze and develop directions to improve the quality of functioning of switching nodes of technological network of data transmission under conditions of destructive information impact of the intruder.
Offline character recognition in transport logistic tables
Authors: Yu Bursian E , Demin A M 
Published: December 2021

Abstract
The paper proposes the improved skeleton method of handwritten characters recognition, which is based on the filtering procedure and the principle of alternating shading schemes of skeletonized area on the 4- and 8-timeslinked raster. The procedure of high-frequency filtration based on discrete real cosine transformation or discrete complex Fourier transform with automatic selection of filtration parameters makes it possible to significantly improve the image quality of handwritten symbols, in particular, to eliminate in many cases thin bridges between the areas of symbol element representation. The principle of alternating the painting schemes along the 4- and 8-timeslinked raster makes it possible to get the wave front of the skeletonized area close to a circle. In this case, the broken lines representing the branches of the skeleton graphs retain the shapes of the symbols. Numerical experiments on the construction of skeleton sets and skeleton graphs for recognizable handwritten symbols located in the cells of the tables of logistic transport problems have been performed. Software implementation of the method is proposed.
Search for potentially dangerous constructs in the source code of the program using neural networks
Authors: Zelensky A , Cherkesova L , Revyakina Ye , Korochentsev D 
Published: December 2021

Abstract
This work is devoted to the study of artificial neural networks to search for potentially dangerous constructs in the source code of the program. A modification of the existing analyzer programs is proposed for a better search for vulnerabilities in software. The use of neural networks will allow programmers and analysts to find those vulnerabilities that have not yet been added to the database. As a result of the research, it was found that the use of neural networks to identify specified constructs is a more effective solution than searching through a database of vulnerabilities, since it allows you to identify not only those constructs that are in the database, but also suspicious code sections.
On the comparison of two approaches to intersectoral balance analysis
Authors: Obrosova N , Shananin A , Spiridonov A 
Published: December 2021

Abstract
The diversification of the inter-industry connections of modern economies seriously hindered the analysis of production networks evolution and input-output balances projection, that traditionally was made by the Leontief Input-Output balance model. That is why the new approaches have begun to develop, that take into account the substitutability of products and services in modern supply networks. In this work we discuss the quality of the new approach to the intersectoral linkages analysis, that is based on the nonlinear model of resource allocation with Cobb-Douglas production technologies. We compare this approach with the traditional Leontief’s scheme of intersectoral connection studying. We make evaluations using the both of methods for large economies, that are on different stages of economic development.