bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strength of welded joint sunder quasi -brittle fracture
Authors: Shakhmatov M V , Usmanova E A 
Published: January 2020

Abstract
In the study of the crack resistance of welded joints with constructive incomplete welds, which are regulated by welding GOSTs and have a wide practice of application, including for critical structures, it is necessary to keep in mind that these stress concentrators on the sharpness of their tops are significantly different from fatigue and operational cracks. Welding defects have the same difference: faulty welds, faulty fusions, undercuts. This paper shows that the strength of welded joints with structural faulty welds in addition to mechanical characteristics and the length of the faulty weld also depends on the radius at its top. Based on the ratios of fracture mechanics, a strain fracture criterion is proposed -the critical opening of the concentrator under consideration, depending on the radius at its top. At the same time, with the reduction of the radius at the top of the concentrator to a certain critical value, comparable to the radius at the top of the crack, the proposed criterion coincides with the material characteristic according to GOST 25.506-85 – the critical crack opening. Dependence for assessing the quasi-brittle strength of welded joints with faulty welds based on the critical disclosure of the concentrator under consideration satisfactorily corresponds to the experimental data on samples from the AMg6 alloy.
Experimental definition of rational modes of shock-acoustic treatment
Authors: Skobelev S B , Kovalevsky V F , Bezzateeva E G , Bury G G , Poteryaev I K 
Published: January 2020

Abstract
The paper presents the results of experimental studies to determine the rational technological parameters of shock-acoustic treatment (SAT) in order to provide the best antifriction properties for the outer surfaces of parts made of Steel 45. On the basis of experimentally selected processing modes, the specified values of overlap coefficients for the ultrasonic instrument and workpiece contact areas are determined. The use of shock-acoustic treatment with simultaneous application of a solid lubricant coating allows the surface microhardness to be increased almost by the factor of two and the roughness to be reduced to Ra 0.2.
Study of the effect of feedback on dynamic stability of hydraulic
Authors: Syrkin V V , Galuza Y F , Kvasov I N , Fedorova M A 
Published: January 2020

Abstract
The possibility of using hydraulic feedbacks in hydraulic automation systems to improve the dynamic processes in transient conditions (acceleration or deceleration of actuators), which provide for regulators with elastic shut-off and control elements. As parameters of feedbacks pressure in the hydraulic system, speed of movement of Executive bodies and their derivatives are provided.
Study of the unusable liquid propellant residues evaporation processes parameters in the tanks of the launch vehicle expended stage in microgravity
Authors: Trushlyakov V I , Urbansky V A , Pustovoy N V 
Published: January 2020

Abstract
A method is proposed for studying the evaporation process of unusable rocket propellant (RP) residues in an expended stage (ES) under weightless conditions. Two options were considered as boundary conditions for liquid RP residues: a) liquid drop distribution in N identical drops, whose surface decreases during evaporation and b) the liquid distribution in the lower tank bottom and the mirror presence, whose area decreases during evaporation. A high-temperature stream of hydrogen peroxide decomposition products is used as a heat carrier (HC) fed to the fuel tank. The physical and mathematical model of the liquid evaporation process is based on the first thermodynamics law. Based on the analysis of the Frud and Grashof criteria, the assumption that there is no convection movement inside the drop (Rayleigh number is less than critical) for both boundary conditions variants, the heat transfer coefficient of the gas-vapor mixture (GVM) produced in the tank is determined due to the regression dependence obtained under ground conditions as a function of the Nusselt, Reynolds and Prandtl numbers. GVM parameters for the considered boundary conditions variants and the proposed physical mathematical model are compared with the results obtained earlier for the boundary conditions variant of uniform fluid distribution over the inner tank wall (third boundary conditions variant) and the boundary layer theory usage based on integral impulses, energy and diffusion ratios. The thermophysical GVM parameters and the GVM exhaust velocity for oxygen and kerosene are provided for two boundary conditions types, using the example of Soyuz-2.1.v type fuel tanks. The total mass of the RP residues evaporation system structure is less than 1.3% of the total “dry” ES design mass.
Possibilities for calculating rubber-cord shells in modern finite-element analyses packages
Authors: Tsyss V G , Strokov I M , Sergaeva M Yu 
Published: January 2020

Abstract
As flexible inserts of various designs, including pipeline systems, vibration-insulating pipes are used, which act as compensators to reduce the resulting deformations and vibration loads. The main element of the design of the pipe, perceiving the action of internal overpressure, is a rubber-cord sheath. To study the possibility of calculating rubber-cord shells in modern finite element analysis packages in the present work, the cylindrical shell of the vibration-insulating pipe has been simulated and its stress-strain state in the software package has been calculated. Since the RCS is a composite design, the simulation was carried out using the built into modules. The results obtained make it possible to analysis the composite material of the RCS and to determine the criteria for shell destruction.
A study of the contact of the wheel with the rail for various conditions of freight car
Authors: Vorobev A A , Konogray O A , Krutko A A , Malakhov I I 
Published: January 2020

Abstract
The paper presents the results of calculations of the parameters of contact interaction of the wheels of a freight car with R65 rails (wheel wear rate, areas of wheel contact spots with rails, friction power capacities in contact spots) for various operating conditions on the Russian Railways road network. The choice of groups of operating conditions was made on the basis of the methodology for ranking the characteristics of the main roads in the plan and profile. The quantitative values of the parameters of contact interaction were established, and their comparative analysis was carried out for the conditions under consideration.
Method for determining optimal parameters of vortex devices for drying compressed air to reduce operating costs of production processes
Authors: Yakovlev A B , Yakovleva E V 
Published: January 2020

Abstract
For most technological processes, low humidity air is used, obtained in various ways. The possibility of using the vortex effect for drying compressed air used in industrial plants and providing savings in operating costs is shown. A mathematical model of the process for reducing moisture content is developed. A method for calculating the optimal geometric dimensions of the drying device is established. The main goal is to develop an effective device for air drying and calculate its optimal parameters. The developed method of calculation allows one to determine the optimal geometric dimensions of the vortex device for drying compressed air, which is more cost-effective, based on the minimum moisture content under the condition of low hydraulic losses.
Analysis of complex product design problem using an L-partition approach
Authors: Adelshin A V 
Published: January 2020

Abstract
In this paper, we analyze the complex product design problem using the model of the partial maximum satisfiability problem. In previous papers, estimates of the cardinality of L-complexes of polyhedrons of the SAT and the MAX SAT problems were obtained. In this paper, a relation of the cardinality of the L-complexes of the partial MAX SAT problem and the corresponding SAT problem is obtained. Using this result, it is possible to obtain theoretical estimates of the cardinality of the L-complex of the polyhedron of the complex product design problem on the basis of similar estimates for the SAT and the MAX SAT problems.
On the properties of the solutions of the problem of cross-diffusion with the dual nonlinearity and the convective transfer
Authors: Aripov M M , Muhamediyeva D K 
Published: January 2020

Abstract
In this work, special methods for studying nonlinear parabolic equations were developed that allow a fairly detailed study of nonlinear problems based on self-similar and approximately self-similar solutions and the construction of an analogue Zeldovych-Kompanees type solution for a cross system, since the study of self-similar equations is relatively simpler in comparison with equations in private derivatives. Studied the properties of solutions to the problem of a biological population of the Fisher-Kolmogorov type in the case of cross-diffusion with the dual nonlinearity and the convective transfer. An estimate of the solutions is obtained, and on the basis of it the problem of choosing the initial approximation for the numerical solution of the Cauchy problem is solved.
Development of digital twin for composite pressure vessel
Authors: Burov A E , Burova O G 
Published: January 2020

Abstract
The present study is devoted to developing a digital twin for a composite overwrapped pressure vessel (COPV) used in electric propulsion engines of spacecraft. The digital twin is used to predict the future behavior and performance of a real physical object based on the currently available information without carrying out expensive and time-consuming full-scale prototyping and testing. Multiscale approach is employed to link the macroscopic stiffness degradation and failure with a progressive damage evolution at the microlevel of composite. The computational models for the stress state and failure analysis at different scale levels are presented. Based on a comparative analysis of the traditional approach for assessing the load-bearing capacity of the COPV and its digital analogue, the advantages of the latter are shown as the predicted burst pressure is in good agreement with the experimental results.
Construction a functional for comparison images of objects
Authors: Chukanov S N 
Published: January 2020

Abstract
The problem of comparing two diffeomorphic images is presenting in the paper To solve the problem, a functional is formed that characterizes the evolution of image transformation from the initial to the terminal, and a penalty for deviating the trajectory from the required one. The problem of comparing two images using the construction of a functional with the optimal image metamorphosis is considered. The metamorphosis of images of objects from initial to terminal using functional forms is considered.
Two ways for numerical solution of the Kramers problem for spatial diffusion over an edge-shaped barrier
Authors: Chushnyakova M V , Gontchar I I , Zakharov A V , Khmyrova N A 
Published: January 2020

Abstract
Thermal decay rate over an edge-shaped barrier at high dissipation is studied numerically through the computer modeling. Two sorts of the stochastic Langevin type equations are applied: (i) the Langevin equations for the coordinate and conjugate momentum (LEqp, the phase space diffusion) and (ii) the reduced Langevin equation (RLE, the spatial diffusion, overdamped motion). The latter method is much faster and self-similar; however, one can doubt about its applicability in the case of an edge-shaped barrier with a discontinuous force. The reason is that a formal condition of the applicability of the RLE is not fulfilled since the curvature of the potential profile at the barrier is equal to infinity. The present numerical study demonstrates that, for large friction, the decay rate calculated using the RLE agrees with the rate resulting from the more exact LEqp. Moreover, it turns out that the influence of the position of the absorbing border is similar to the case of harmonic potential known in the literature.
Presentation of preferences in multi-criterional tasks of decision-making
Authors: Egamberdiev N , Mukhamedieva D , Khasanov U 
Published: January 2020

Abstract
Annotation. Fuzzy relationship preferences are widely used in multi-criteria decision-making problems. Although the fuzzy relationship of preference has been intensively researched, and they are very useful in making decisions, there are still problems that need to be investigated. The paper proposes conditions under which fuzzy relationship preferences improve the quality of decision-making.
Models of recognition algorithms based on linear threshold functions
Authors: Fazilov Sh , Khamdamov R , Mirzaeva G , Gulyamova D , Mirzaev N 
Published: January 2020

Abstract
The problem of constructing a model of recognition algorithms in the conditions of high dimensionality of feature space is considered. To solve this problem, a new approach suggests that it takes into account the interconnectedness of the given features. The main concern of this approach is to isolate representative traits and form preferred combinations of traits. A distinctive feature of the proposed model of algorithms is to determine a suitable set of elementary threshold rules within the framework of the preferred combinations of representative features and build a proximity function based on this set of feature combinations. Scientifically, the results of this work in the aggregate represent a new solution to a scientific problem related to improving the reliability of recognition algorithms based on radial functions. The practical significance of the results lies in the fact that the developed algorithms can be applied in medical and technical diagnostics, geological forecasting, biometric identification. To test the performance of the proposed model, experimental studies were performed.
Reducing the dimensionality of feature space in pattern recognition tasks
Authors: Fazilov Sh , Mamatov N , Samijonov A , Abdullaev Sh 
Published: January 2020

Abstract
The definition of an informative set of features is one of the important tasks in pattern recognition. Typically, the determination of informative features is carried out using two types of methods. The first type of methods is “direct methods”, they are directly aimed at identifying informative sets of attributes. And the second type is called "inverse methods", these methods serve to build informative sets of signs by eliminating uninformative signs from the attribute space. This article is devoted specifically to the development of the second type of method; it proposes an accelerated method and an algorithm for determining non-informative features based on the selected non-informative criterion.
The Nash optimal control of forest ecosystem at risk of fire ignition
Authors: Guts A K , Kabanov A N , Volodchenkova L A 
Published: January 2020

Abstract
We are exploring a mathematical model of a forest ecosystem that is at risk of fire ignition when the ambient temperature rises. We believe that the main characteristic in this case is the amount of carbon entering the atmosphere. Fire control measures are an external control factor that is at the disposal of the Forestry Administration. We were interested in finding the optimal behavior strategy, with which the Forestry Administration could take the necessary measures in a timely manner. We describe the forest ecosystem by a differential equation with two external control factors and apply the theory of differential games to the search for optimal control. By optimal control we mean the Nash equilibrium that we search for our model.
We also complicate our model by introducing into consideration a differential equation with four control external factors describing the mosaic-layer phytocenosis.
Algorithmization control of complex systems based on functioning tables
Authors: Kabulov A V , Normatov I H , Karimov A 
Published: January 2020

Abstract
This paper is devoted to algorithmic models and methods of managing complex systems based on algebra over the functioning tables. To build a control system, a description of processes, both strictly sequential and parallel, is required. For this, a unified description of processes with specified operations is introduced in the form of functioning tables. Then, algorithmic support for the equipment and organizational structure under consideration is built on the basis of algebra over the tables of the functioning of a complex system.
Building a model of recognizing operators based on the definition of basic reference objects
Authors: Kamilov M , Fazilov Sh , Mirzaeva G , Gulyamova D , Mirzaev N 
Published: January 2020

Abstract
The paper considers issues related to the construction of a model of recognizing operators, focused on the classification of objects in conditions of high dimensionality of a feature space. A new approach to constructing a model of recognition operators based on the construction of multi-level proximity functions is proposed. In this case, the construction of the model was carried out within the framework of recognition algorithms based on the calculation of estimates.
The goal of this work is develop a model is to form independent subsets of interrelated objects, highlighting a set of representative pairs of features. A distinctive feature of the proposed operator model is the definition of a suitable set of threshold functions when constructing an extremal recognition operator.
The purpose of this article is to develop a model of recognizing operators based on the calculation of estimates using two-dimensional threshold rules. Scientifically, the results of this work in aggregate represent a new solution of a scientific problem related to the issues of increasing the reliability of recognizing operators based on the evaluation of estimates. The practical significance of the results lies in the fact that the developed operators and programs can be applied in medical and technical diagnostics, geological forecasting, biometric identification and other areas where it is possible to solve the problem of classifying objects defined in a space of large dimensionality.
An iterative method for solving nonlinear equations of real gas pipeline transport
Authors: Khujaev I , Mamadaliev Kh 
Published: January 2020

Abstract
The study is devoted to the development of a numerical method to solve the equations of pipeline transport of compressible gas, taking into account the forces of resistance, gravity, local and convective components of the gas inertia force in the isothermal mode of factors. The power of the unknowns in the momentum conservation equation is reduced with the introduction of the auxiliary function of natural logarithm of the reduced density. Autonomous equations of linear combinations of the hydrodynamic flow rate and a newly introduced function were compiled with the participation of the propagation velocity of small pressure disturbances. In this paper, an iterative method is developed to solve equations for the implementation of the input condition for pressure and output condition for mass flow; it allows determining the unknown boundary and internal values of gas-dynamic parameters. The results of a computational experiment on the route change in flow indices at various slopes of the gas pipeline route are analyzed.
Determination of non-informative features based on the analysis of their relationships
Authors: Mamatov N , Samijonov A , Niyozmatova N 
Published: January 2020

Abstract
In solving most of the practical problems associated with classification, a heuristic approach is widely used. Currently, many heuristic methods and algorithms based on various heuristic criteria have been developed. The most popular criteria are heuristic informational criteria. These criteria are related to the assessment of the separability of these classes and are based on the fundamental hypothesis of recognition compactness, i.e. with an increase in the relationship between classes, their separability improves. If traits maximize relationships, they are called "good." Such heuristic criteria are widely used and give good results in solving practical problems, but they are poorly studied in theoretical terms. At present, the method for choosing non-informative features, taking into account the relationship of features based on heuristic criteria, has not yet been developed. The article considers the problem of determining informative features by eliminating uninformative ones.
Particle swarm method for solving the global optimization problem using the equilibrium coefficient
Authors: Muhamediyeva D T 
Published: January 2020

Abstractthe paper deals with the case when particles are evenly distributed in ravines, using the equilibrium coefficient to update the particle velocity. the method of optimizing a swarm of particles in the case of a "ravine" is one of the most effective approaches for multi-extremal optimization. however, in the existing methods of optimizing the swarm of particles with the "ravine" methods, the number of particles around the ravine is very different from each other, which makes it difficult to find high-quality algorithms in all the ravines. thus, the computational resources are distributed in the ravines in a more balanced way.
Simulation and numerical study of two-phase flow in a centrifugal dust catcher
Authors: Nazarov F Kh , Malikov Z M , Rakhmanov N M 
Published: January 2020

Abstract
Numerical study of turbulent swirling air flow with solid particles in a centrifugal dust catcher is carried out in this paper. The Spalart-Allmaras modified turbulence model (SARC) has been used to construct a mathematical model with account of the interaction between solid particles and air mass. The Lagrange approach has been used to study the trajectory of solid particles. The numerical results obtained are compared with experimental data. The experiment has been conducted with zinc powder on a laboratory stand of a centrifugal dust catcher. …
Application of network analysis methods in the selection of information sources
Authors: Olgina I G 
Published: January 2020

Abstract
A possibility of applying network analysis for solving practical tasks related to the selection of information sources. It is proposed to consider the following algorithm of actions necessary for qualitative selection of sources of information based on the analysis of the citation network of scientific publications. A possibility of applying a information sources ranking on a list of "important" articles of a citation network, is reviewed. Existing algorithms of clustering graphs are reviewed and analyzed. A formal description of the network is given and parameters of centrality of citation network nodes are presented. A method of calculating a degree of centrality according to relevance of network nodes, with importance and weight of a series of parameters that are required for publications ranging articles of the citation network. A mathematical model of selecting documents for a library collection on a list of "important" articles of a citation network, is reviewed.
Numerical method of modeling of a current of viscous liquid with free borders
Authors: Panichkin A V 
Published: January 2020

Abstract
The final and differential method with application of the fixed regular grids with constant steps is developed for modeling of a current of a layer of viscous liquid with free and moving firm surfaces, the analysis of orders of accuracy from net steps and to iterative parameter is carried out at application of the scheme of the second and first orders in the corresponding sizes. When modeling two-dimensional currents of viscous incompressible liquid preservation of orders of accuracy of the considered differential scheme and preservation of volumes of liquid is shown.