bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the energy efficiency of weather onboard radars of the X and Ku ranges with electronic scanning
Authors: Ryzhikov M B , Novikova Yu A
Published: December 2022

This work contains a comparison methodology and the resulting mathematical ratio, which can be used to compare the power of signals reflected from range cells with a certain water content. It is assumed that there is an electromagnetic wave attenuation between the radar and the range cell on the signal propagation path, which depends on the wavelength and weather conditions. Simulation results are presented that allow us to recommend the use of Ku-band radars in light precipitation on short-range aircraft.
Effect of wind load on waveguide strength
Authors: Brungardt M V , Brungardt A V , Goncharova E A , Li O A
Published: December 2022

The article considers the features of the influence of wind load in the Arctic and Far North regions on the static and dynamic state of direct waveguides. Waveguides have a thin-walled design with restrictions on wall deflections, so the theory of plates and shells is used to calculate them. In the static state, the wind load is modeled by uniform pressure on one side of the waveguide. This made it possible to obtain an analytical solution to the problem by the plate theory, identify the features of the stress distribution over the waveguide structure, and clarify the solution compared to the beam theory. Comparing the results of the calculation according to the proposed method with the results of beam theory showed good convergence. The dynamic state was estimated by the first natural frequency of waveguides, considering ice deposits. The results of the calculations showed a significant impact of ice deposits on the frequency of oscillations and showed the need for deicing.
Stationary stress-strain state of a three-layer viscoelastic cylindrical shell under normal loading
Authors: Kuldashov N U , Marasulov A M , Yunusov G G , Sh Ruzimov A , Hojiev T S
Published: December 2022

Multilayer viscoelastic cylindrical shells have found their wide application in construction, mechanical engineering, aircraft and rocket engineering. The aim of the work is to investigation the reaction of an infinitely long three-layer cylindrical shell to the action of a normal load moving along an axis with a constant to resonant velocity. The paper presents a mathematical formulation of the problem, developed solution methods and obtained numerical results for the problems of stationary deformation of an infinitely long three-layered cylindrical shell under normal loading. The equations of motion of the bearing layers satisfy the Kirchhoff-Love hypotheses. The solution methods are based on the joint application of the integral Fourier transform in the axial coordinate and the decomposition of all given and desired quantities into Fourier series in the angular coordinate. The outer and inner shells satisfy the Kirchhoff-Love hypotheses. The Lame viscoelasticity equation is used as a linear equation of the filler motion. An effective algorithm for solving the problem of osculations of a three-layer viscoelastic cylindrical shell under normal loading has been developed on a computer. Critical velocities of wave propagation in a three-layer shell under the influence of moving loads are found.
Temperature influence on elastic-hydrodynamic interaction of rolling bodies in roller bearing
Authors: Kudryavtsev I V , Ivanov V A , Mityaev A E , Kolotov A V , Rabetskaya O I
Published: December 2022

The lubricating layer located between the rolling bodies plays a crucial role in ensuring the service life of the bearings. Calculating the contact of rolling bodies with each other taking into account their compliance and lubrication parameters is a complex elastic-hydrodynamic problem, for the solution of which complex computer programs are usually used. The paper proposes a hybrid approach based on a separate solution of elastic and hydrodynamic problems with subsequent coordination of the complete solution. The semi-analytical approach of the created method allows solving a large range of problems, and was used in this work to assess the effect of temperature on the stress state of rolling bodies in a roller bearing. The results of calculations show the operability of the procedure and made it possible to establish the dependence of contact stresses on oil viscosity and temperature. The proposed approach is applicable for solving elastic-hydrodynamic problems for any bearings.
Definition of limit state of flexible pipe material in coiled tubing technology
Authors: Dzhuraev R F , Naumkin E A , Kuzeev I R
Published: December 2022

Currently, the use of coiled tubing technologies has become widespread in drilling and oil production. The flexible pipes (FP) used in this technology undergo a complex of several impacts that accelerate the process of damage accumulation and thereby cause an accelerated process of seats of destruction formation, which often leads to accidents. Statistics show that the main reason for the destruction of the FP is the fatigue of the material loading and basically it is a cyclic bending according to the repeating stress cycle scheme. This loading scheme has a feature that is associated with the fact that tensile loads occur mainly in the convex zone of the pipe and compressive loads in the concave zone. Since the physical and mechanical properties of steels under stretch and compression are different, the process of damage and destruction accumulation during cyclic stretch and cyclic compression will have a different character. Information about the patterns of changes in the properties of the FP material allows to estimate the period of reaching the limit state and, thereby, prevent accidental destruction. In this regard, fatigue tests were carried out with a step-by-step measurement of magnetic characteristics that are structurally sensitive to the accumulation of fatigue damage. The determination of the stress amplitude for the FP fragment was determined by preliminary calculation in the ABAQUS PC. The test results showed that during cyclic stretch of the samples, the magnetic characteristics for assessing the limit state in the FP material were not informative. Notably in samples loaded with cyclic compression, the results of magnetic characteristics measuring (the resulting intensity and the gradient of the intensity of the constant magnetic field) showed sensitivity to the onset of the limit state. Based on the conducted studies, it is proposed to control the limit state of FP in the concave zone, where compressive loads mainly occur. These measurements allow us to estimate the value of the residual life of the FP material and to put this object out of operation in a timely manner, preventing accidental destruction.
On the propagation of intrinsic viscoelastic waves in a cylindrical shell
Authors: Sh Usmanov B , Safarov I I , Kh Teshaev M , Umarov A O , Kurbonova X
Published: December 2022

The article illustrates that viscoelastic wave in an extended cylindrical shell of circular cross-section. To solve boundary value problems used classical methods of mathematical physics. The unwavering quality of the comes about of the work is guaranteed by the rightness of the detailing of issues, the utilize of the classical device of scientific material science and other demonstrated strategies for tackling issues of wave engendering, the consistent legitimacy of the conclusions and the great assentation of the comes about with the uncommon cases known from the references.
Ensuring the unity of measurements of the neutron radiation rate absorbed dose in the field of clinical neutron radiation dosimetry
Authors: Fedorov S G , Berlyand A V , Dyachenko V M
Published: December 2022

Development of neutron radiation therapy arises the question of ensuring the uniformity of measurements of the absorbed dose and the absorbed dose rate of neutron radiation. FGUP “VNIIFTRI” improved the primary method and means of reproducing the unit of neutron radiation absorbed dose rate within the framework of improving the State primary standard of units of absorbed dose rate and neutron dose equivalent rate GET 117-2010. A set of ionization chambers has been created and the upper value of the reproduction of the unit of absorbed dose rate of neutron radiation has been expanded. A hardware-methodical complex has also been developed for transferring a unit of absorbed dose rate of neutron radiation to nuclear physics facilities used in neutron radiation therapy. As a result the expanded relative uncertainty of reproduction of the unit of absorbed dose rate does not exceed 3%, the expanded relative uncertainty of the transmission method does not exceed 0.5%. The resulting level of accuracy is in line with the recommendations used in neutron beam therapy.
Experimental studies of the dynamics of the proposed design of the presser foot with an additional conical spring
Authors: Mavlonova Iroda , Akhmetjanov Mansur , Vokhidova Munira , Fayziev Sirojiddin , Shokirova Sayyidaposhsho
Published: December 2022

This article is devoted to light industry equipment, namely sewing machines that are utilized in the manufacture of clothing, footwear and knitwear. The disadvantage of this design is the lack of vibration damping of the trigger and rod caused by changes in the thickness and structure of the sewing material, the impact resistance of iron and the incompatibility of the rotating elements in the sewing machine.
Oscillations of the outer bush of composite roller of the thread guide in the sewing machine
Authors: Tursunova G , Djuraev A , Ganchini Sh , Mansuri D , Mansurova M
Published: December 2022

The diagram of thread guide with composite rollers in a sewing machine is given in the article. Based on solving the problem of oscillations of the outer bush of the compound roller of the thread guide, the dependence of changes in the amplitude of deformation values of cushioning bush has been obtained. Values of stiffness coefficient of cushioning bush of compound roller have been substantiated.
On the steady-state motion in the vertical plane of an airship of the classical scheme
Authors: Grumondz V T , Osipova V A
Published: December 2022

We consider the construction of the mathematical model of motion in the vertical plane of an airship of the classical scheme and algorithms for calculating the parameters of its steady-state motion in various cases. The motion of an airship of rather small volume, for example, a remotely piloted airship, is investigated. Some types of possible motions in the vertical plane satisfying the proposed system of equations of steady-state motions are described. Such motions include horizontal flight with constant velocity, rectilinear flight in climbing mode, and descent at a constant trajectory slope angle. The cases of rectilinear flight of an airship along inclined trajectories, the inclination angle of which is not small, taking into account the nonlinear components of the aerodynamic characteristics, are also considered. We have developed algorithms for calculating the steady-state motions of an airship for various cases of flight along inclined trajectories corresponding to various methods of takeoff and landing of an airship without a special cable landing system. This allows us to construct trajectories that provide short takeoff distances and low landing speeds of the airship, which corresponds to the solution of the problem of safe operation of the airship as a technical system. The results of numerical calculations of steady-state motion parameters obtained in accordance with the constructed algorithms are presented. The calculation results are presented graphically.
Computer modelling of dynamics of the thread in technological process
Authors: Adizova Aziza , Abdieva Gulara , Mavlanov Tulkin
Published: December 2022

The article covers the technology of computer modeling of technological processes on example of the research of transverse oscillations of the thread in weaving process. During the formation of the fabric, various dynamic processes took place, including fluctuations in the threads. As an example, the longitudinal oscillations and tension of the threads in the process of surf on a loom are considered. The program and the results of the calculation are given using the software package “Mathcad”.
Methods for studying the properties, structure and composition of materials
Authors: Yakovlev Valeriy A , Berezhnov Danil A
Published: December 2022

To solve various practical problems, it is necessary to have information about the features of modern methods for obtaining and processing various materials, as well as the features of their rational use and properties. For example, it is necessary to collect information about the structural features and properties of materials and alloys, in particular, non-metallic materials, fuels and lubricants, as well as operating fluids considered in materials science. All this information can be extremely useful for the operation and subsequent repair of vehicles. As one of the key goals of materials science, one should consider the establishment of fundamental relationships between the composition, structure, and properties of various metals and alloys. It is noted that the solution of such a problem will require an extremely thorough study of the structural features of metals and alloys at the macro and micro levels. It is these features and data that will be given special attention in this article.
New diamond-like phases boron nitride TA-type
Authors: Ryashentsev D S , Burmistrov V A
Published: December 2022

A theoretical study of the structure and electronic properties of three new polymorphic varieties of diamond-like phases of boron nitride, the atoms of which are in equivalent crystallographic positions, was carried out by the density functional theory (DFT) method in the generalized gradient approximation (GGA). The primary structures of these phases were built modelically from the corresponding carbon diamond-like phases by replacing carbon atoms with alternating boron and nitrogen atoms, so that an atom of one kind was surrounded by atoms of another kind. As a result of the calculations, the possibility of stable existence of new structural varieties of boron nitride was established: BN-TA1, BN-TA2, BN-TA3. The sublimation energy of new BN phases varies from 17.08 to 17.59 eV(BN)−1. The new BN polymorphs are wide-gap semiconductors with a band gap at the Fermi energy level from 3.6925 to 5.4565 eV.
Effect of cutting parameters on temperature in the cutting zone in a high-speed steel turn-milling process
Authors: Matlygin Georgy , Savilov Andrey , Pyatykh Aleksey , Timofeev Sergey
Published: December 2022

The article aims to analyze the orthogonal milling method which can be applied in machining powder high-speed steels. To conduct the experiment, BÖHLER S390 MICROCLEAN HSS and carbide insert cutters were selected. A turning center with a driven tool was used. To examine the temperature in the cutting zone, a mathematical model of an orthogonal turn-milling process was developed and optimal cutting data were chosen using the results of simulation procedures. The model obtained can be used to analyze temperature changes in the cutting zone. The experiments determined the effect of the cutting parameters such as tool feed, speed and radial depth of cut on temperatures in the cutting zone.
Simulation of high-speed machining processes by multi-edge mills
Authors: Gordeev Yu I , Yasinsky V B , Spirin E A , Binchurov A S , Vakulin M S , Filippov S V
Published: December 2022

Based on the results of the numerical experiment by finite element analysis (FEA) the mill design having the initial tooth profile in the form of a trapezoid located along two intersecting spiral lines with angles of inclination of 14 and 71 degrees. As a result, about 70 cutting protrusions – are formed on the cylindrical surface, i.e., the total number of cutting edges in the cutting dynamics can be up to 280 blades. A model and methods for determining the geometric and kinematic parameters of cutting milling the required shape, dimensions and quality of the surface of the detail are proposed. The roughness at optimal cutting modes correspond to the Ra = 1.25-0.63 μm, which is comparable to grinding processing. The shape of individual chip elements can be described as spherical, its dimensions do not exceed 20 μm, and larger chip agglomerates have submicron and nanostructural fragmentation. Due to the increase of edges on the surface of new design mill increase the efficiency and intensity of deformation processes too (the number of single cutting cycles is up to 4000-6000 s-1). This is also in good agreement with the numerical estimates by the FEA method.
Development of technology for processing internal channels of small-sized parts based on computer modeling
Authors: Zverovshchikov Alexander , Gurin Pavel , Steshkin Artem , Mironychev Nikolay
Published: December 2022

In the manufacture of small-sized parts, the finishing of the internal channels of a complex cross-section with a coating is particularly difficult. To solve this problem, it is proposed to use centrifugal processing with steel balls in containers with planetary rotation. The paper presents the results of computer simulation of the contact interaction of balls with the surface of the part channel. These data made it possible to establish that at certain velocities and directions of the flight vector at the moment of contact, the balls allow you to remove the micro-roughness of the coating without violating the integrity of the part base. The simulation results formed the basis for the design of an industrial installation and the assignment of centrifugal-planetary processing modes. The proven technology of finishing the internal channels of small-sized details provided a reduction in the proportion of damaged parts by 4...4.3 times relative to the basic technological process.
Method of cutting metal ingot with changing direction of deformation
Authors: Voronov Vladimir , Videnin Sergey , Masich Igor
Published: December 2022

The paper considers the priority problem of cutting an ingot with a changing direction of rolling which can be presented as a priority problem of packaging with incompatible categories and dynamically changing bin sizes. This problem is a NP-complete optimization problem which is often found in the production of metalwork. Priorities reflect the “importance” of manufacturing elements for production and incompatible categories show that elements of different thicknesses cannot be made from the same bin. In addition, we use guillotine restrictions to take into account the specifics of production. The problem of cutting the ingot is characterized by the fact that the bin sizes are not known in advance. Thus, the task is to find the optimal bin sizes, the sequence of actions and the placement of elements in these bins. We propose a sequential tree metaheuristic to solve this problem. It is a deterministic method. This method is based on sequential metaheuristic which was proposed by the authors earlier. The proposed method also has the ideas of dividing a set of elements into groups and subgroups by thickness and priorities, as well as their sequential packing. However, it differs from previous one in that it uses a tree to represent options for rolling operations. The best subtree from the point of view of any criterion, formed as a path from the root to one of the nodes, will be the solution. The ability to find several better solutions with the same value of the criterion is another advantage of the proposed method. Such a situation may arise, for example, for a square ingot. In this case, two solutions are possible with accuracy up to 90 degrees rotation of the workpieces. The priority heuristic is used as a heuristic to solve the packaging subproblem. The results of computational experiments are based on test cases which were compiled specially. Test instances differ in the number and characteristics of elements, categories, priorities. The results show that the metaheuristic proposed by the authors solves the problem effectively.
Investigation of the possibility of controlling the formation of physical and mechanical properties of aluminum alloys under pressure crystallization
Authors: Denisov M S
Published: December 2022

The study of scientific and technical materials showed that the existing control systems for technological processes of casting with crystallization under pressure are not effective enough. The paper presents a control system capable of real-time measurement, control and correction of the main technological parameters of the process, such as the time and nature of the temperature distribution in the tooling and casting, the rate of pressure imposition on the crystallizing metal, the magnitude of the applied pressure. These parameters have a direct impact on the formation of the properties of the final product. The paper defines the parameters of the response of the control system to fast crystallization processes for the timely prediction of the properties of the final product. The paper proposes a technology for metal processing by pressure prior to the onset of crystallization. In the process of conducting experimental studies in castings, it was possible to achieve the same uniform distribution of components, gas and non-metallic inclusions, as in a superheated liquid metal, bypassing the development of diffusion. As a result of ultrafast application of pressure to a level of 500 MPa on the liquid metal, it was possible to realize the process of compression of the crystal lattice to such limits at which it was possible to exclude the diffusion of components along structural defects. Due to the programmed application of pressure on the liquid and crystallizing one, the idea of controlling the processes of distribution of intermetallic compounds, non-metallic and gaseous inclusions has been realized.
Application of metal powders to bronze bushings
Authors: Golinitskiy Pavel , Temasova Galina , Antonova Uliana , Cherkasova Elmira , Vergazova Julia
Published: December 2022

Bronze bushings have become widespread in the mobile data of machines, the reuse of which is complicated by the insufficient elaboration of the recovery technology, which has a negative impact on environmental friendliness. To improve the current situation, we carried out research on the development of a technology that allows electrocontact welding of metal powders of nickel and iron onto bodies of revolution made of bronze. The main difficulty on the way of applying this method of recovery is the different melting temperature of bronze and welded metal powders, but the use of a special shell developed by us and the modes identified made it possible to solve this problem.
Investigation of nanostructured hard metal composites obtained from powder mixtures (WC-Co)-Al2O3
Authors: Gordeev Yu I , Zeer G M , Yasinsky V B , Binchurov A S , Usevich N I , Timoshev P V , Filippov S V
Published: December 2022

A new stereological model of nanostructured hard metal composites is suggested which describes the packing density, structural parameters and fracture toughness depending on the sizes, volume of the carbides and addition of nanoparticles Al2O3. The results of complex theoretical and experimental investigations of hard metal composites based on powder mixtures (WC-Co)-Al2O3(nano) are presented, which confirm the possibility of improvement of the structure parameters (with the average size of the binder interlayer being up to 0.12 μm and carbide grain up to 1μm), increasing the hardness 15-18 HV, GPa, fracture toughness, K1c, 16-19 MPa m1/2, transverse rupture toughness, σи - 2700 MPa. The results of the modeling experiments are in satisfactory agreement with the measurements of structure parameters and fracture toughness.
Research of composition of oily part, obtained from the “Yellow oil” - wastes of pyrogas cleaning process by the method chromatography-mass spectrometry analysis
Authors: Tilloev Lochin , Dustov Khamro , Murodov Malikjon
Published: December 2022

In the article, in order to study the properties and composition of organic and inorganic components obtained from processing of waste “yellow oil” by alkaline purification of pyrogas from sour gases in the existing gas chemical complexes in Uzbekistan and to determine its practical application, they were divided into components for the first time. The hydrocarbon composition of the oily part of the separated compounds has been studied using the gas chromatography-mass-spectrometry analysis method. Based on the results of the gas chromatography-mass-spectrometry analysis, the volumetric quantities of individual components were determined. Based on the results obtained, the areas of application of the oily part (as thickeners, fillers and additives) were studied, they were exposed to different functional groups, and preliminary data were obtained on the possibility of obtaining surfactants and raw materials for the paint industry by chemical reactions. Subsequent research has identified tasks that need to be addressed.
Mathematical bases of calculation of gas-dispersed flows in vortex dust collectors
Authors: Barakaev N R , Jalilov R S , Muxammatova U X
Published: December 2022

Development of numerical methods for calculating the movement of gas-dispersed flows in vortex and inertial separators, creation of devices with counter tangential and flows of increased dust collection efficiency, determination of the optimal profile of corrugated channels in order to minimize the release of droplet moisture from inertial separators.
Assessment of the impact of marine ferry routes on the environmental situation of the Baltic Sea based on data from information-measuring systems
Authors: Maiorov N N , Dobrovolskaia A A
Published: December 2022

Passenger and accompanying cargo-passenger maritime transportation on the Baltic Sea acts as systematic elements of the Baltic transnational macro-region. Ships that meet various environmental requirements today operate the ferry routes. The task of ecological safety assessment when introducing new ferry routes takes on special urgency. The paper contains analytical data of the marine ferry transportation industry, the main trends of the industry development. The analysis of the main ferry companies is performed and the main variables for estimating the level of possible pollution of the Baltic Sea are determined. Models for calculation of navigation autonomy by taking into account dimensions of allowable sewage and dry garbage are given. Based on the performed analysis of intensity of operation of sea ferry lines the forecast of areas of the Baltic Sea in which there will be an increase of ecological load is made. The necessity of development of information-measuring system for the assessment of the ecological situation of the Baltic Sea on the main directions of the sea ferry lines is substantiated. The structure of information-measuring system for monitoring of ecological situation at performance of sea ferry transportations is offered.
Method for determining the mass conductivity coefficient of wood when extracting biologically active substances from it
Authors: Safina A V , Valeev K V , Ziatdinova D F
Published: December 2022

The article presents a method for determining the mass conductivity coefficient of wood when extracting biologically active substances from it. To implement the method, there was an installation developed, the internal cavity of which is divided into two zones filled with liquids with different concentrations of the extracted substance. The installation zones are separated by the investigated wood material. The determination of the mass conductivity coefficient is made according to the equation obtained from Fick’s first law. As an approbation of the proposed method, we carried out studies on the mass conductivity coefficient of larch wood during the extraction of dihydroquercetin from it with a water-ethanol extractant and arabinogalactan with distilled water. As a result of experimental data processing, mathematical dependences of the larch mass conductivity coefficient during the extraction of dihydroquercetin and arabinogalactan on the process temperature were obtained, which can be used in mathematical modeling in order to optimize the operating parameters of the process.
Software for measurement uncertainty assessment and actual metrological characteristics of viscometers
Authors: Sh M Masharipov
Published: December 2022

The issue of implementation of software for rapid assessment of uncertainty of metrological control results of measuring instruments used in the field of state metrological control and supervision in calibration and evaluation of actual metrological characteristics of operating viscosimeters was considered. An interpretation of the application of the EXCEL program and other software for the special methodology for automating uncertainty calculations developed by us was carried out, which significantly simplified the work and reduced the time spent by specialists in the metrological laboratory. Basic requirements of comparison of software for calculation, calculation and estimation of uncertainty in the realm of mathematical models of validated techniques are determined. The experimental results of the comparative analysis taking into account the set tasks are presented, the most common and effective universal software for calculating the uncertainty of the results of the experiment. The object of the study is universal software for estimating the uncertainty of measurements and other metrological characteristics of viscometers, structured by types of measurements, in the graphic programming environment. The software can be used both in laboratories and in industrial premises. The workplace can be both a metrological laboratory, the working area of which is a table with instruments, and a production room. As a rule, accredited laboratories do not have a special staff of metrologists or specialists who perfectly understand the basics of mathematical statistics and the concept of measurement uncertainty. The complexity and necessary amounts of calculations that are carried out in assessing the uncertainty of measurements require significant laboratory resources.
Transmission and slewing mechanism for highly manoeuvrable small machine transmissions
Authors: Yu Dobretsov R , Ivanov A A , Nuretdinov D I , Malyukova M A , Malyukov S V , Ye Ariko S , Churakov A V
Published: December 2022

A variant of the electromechanical transmission scheme for mobile platforms of small mass, designed primarily for operation in an organized artificial environment under the conditions of dimensional restrictions, is proposed. Typical examples of such environments are greenhouses, gardens and parks. Distinctive features of the proposed transmission are the use of a single traction motor and a power distribution mechanism that allows the use of two modes of side turn: in the range from a given minimum radius to infinity and turning around the center of gravity. The transmission scheme, with some changes, can be extended to mobile chassis of a larger mass - tractors of various traction classes, forestry machines, loaders, mobile robots, etc.
Computational approach to the structure spectral analysis of GERT-network models of mobile object monitoring systems
Authors: Kovalev I V , Kovalev D I , Testoyedov N A , Golovenkin E N , Voroshilova A A , Shatrov A K , Borovinsky D V
Published: December 2022

The paper considers the application of the computational approach to the structure spectral analysis of GERT-network models of mobile object monitoring systems. The structure of the system for monitoring mobile objects using satellite communication channels is presented, in particular, the structure of the system for monitoring the flight path of aircraft. It is shown that the structure of monitoring systems can be represented as a GERT-network model, which allows at the initial stage to consider various options for the formation of interaction between a mobile object, for example, a manned or unmanned aerial vehicle, and a ground control complex. The main idea of the approach is to transform a known graph into a graph with the desired spectrum, which corresponds to a valid implementation of the GERT network graph. Obviously, the set of admissible implementations also includes a graph with the maximum probability of completing the process in a given time. The results are presented, which allow, when analyzing the GERT-network structure of a monitoring system, to assess, by fairly simple methods, the compliance of a structure variant with a number of requirements that apply to the system as a whole.
Reduction of time series forecast variance by the case of ArDL(p, q) models
Authors: Petrusevich D A
Published: December 2022

Combination of time series forecasts or time series models is often considered nowadays in various research papers and is usually a good technique in practice. Still it has got weak theoretical explanation and there’s a lot of work that is going to be done in this field. In the research optimal combination of forecasters in terms of minimal variance is investigated. These results don’t depend on nature of combined models but in the practical part ArDL models describing connections between pairs of time series are considered. Weighted sum of models’ predictions is used as a new prediction with variance that should be less than individual models’ predictions variance. Optimal weights for combination of two models are calculated theoretically. They are based on correlation of combined models and their forecasts’ variance. Optimal model combination variance (variance of the combined models with optimal weights) has been investigated and it has been shown that it doesn’t exceed variances of the combined models. Practical experiments and conditions under which combined time series model is expected to improve forecasts of original ones are in scope of this research. Forecasts of two ArDL models are combined in order to construct forecast with lower variety. This approach can be used in case of more models but theoretical expression of optimal weights is going to be a part of further research. Russian macroeconomical time series statistics and economic data of the USA are used as experimental time series. Combined models have got predictions close to the forecasts of the best models and better than the worst models used in combinations. It’s shown that optimal combination should make predictions of high quality if combined predictors describe different aspects of investigated time series and correlation of their forecasts isn’t very high. Otherwise, it turns into mean forecast of two models.
Application of pseudoinverse matrices in optimal terminal control problems of linear discrete systems
Authors: Matvienko V T , Filimonov A B , Filimonov N B
Published: December 2022

The problem of linear-quadratic optimal terminal control of a linear discrete dynamic system with a vector input is considered. Solutions of the problem based on the apparatus of the optimization form of pseudo-circulation of matrices are given. The solution of the optimal terminal control problem is obtained, which ensures the achievement of the terminal control goal and the passage of the trajectory of the system as close as possible to the specified intermediate points. A complete set of solutions to the problem of optimal terminal control of a bundle of trajectories is obtained.
Exploring the current state and application of quantum computing
Authors: Magomadov V S
Published: December 2022

This paper is focused on the field of quantum computing which is an important area of research these days. The paper gives a brief history of this phenomenon and discusses how it has been developing since its conception. Furthermore, the paper describes the principles on which the quantity computer is built, such as qubits, entanglement, and superposition. It also discusses the necessity to build a quantum computer and how it could an improvement upon the existing computers. In addition, the paper covers some of the fields in which quantum computing could be particularly beneficial. Finally, some of the problems and challenges associated with the development of quantum computing are addressed.
Interaction of two-frequency electromagnetic waves with anisotropic media over hydrocarbon accumulation
Authors: Yanushkevich Viktar F , Dauhiala Dzmitry A , Adamovich Aliaksandr L , Abramenka Siarhei N , Kalintsau Siarhei V
Published: December 2022

The article analyzes the interaction of two-frequency electromagnetic waves with anisotropic media over hydrocarbon accumulation. The behavior of the real component έ3 of the dielectric permittivity tensor is investigated. The choice of signal characteristics is based on the use of different electromagnetic wave emission sources with amplitude and frequency ratio coefficients in the modes of powerful low-frequency and high-frequency signals. The dielectric permittivity tensor component έ3 as a function of dielectric permittivity and frequency of sounding signals was analyzed. Sounding modes of anisotropic media over hydrocarbons are recommended to identify the medium over the deposits and increase the accuracy of determining the boundaries of hydrocarbon accumulation. The obtained results of the research can be used in prospecting geophysics.
Method for measuring and analyzing the complexity and safety of air traffic control
Authors: Yu Filimonyuk L
Published: December 2022

The research proposes a method for measurement and assessing the complexity and safety of air transport systems by comparing the complexity of given air itineraries. The specified complex of dynamic characteristics of the sequence is designed as a formal basis of the method for itineraries’ analysis. The method is illustrated by an example of comparing air trajectories according to different criteria.
Construction of maps for dynamic modes and bifurcation diagrams in nonlinear dynamics using the Maple computer mathematics software package
Authors: Parovik R I , Yakovleva T P
Published: December 2022

The paper considers algorithms for constructing maps of dynamic regimes and bifurcation diagrams in nonlinear dynamics using the example of some oscillatory systems and discrete mappings. The work is educational and methodical and can be used in the educational process when studying the disciplines “Nonlinear dynamics” and “Theory of oscillatory systems”.
Metrological characteristics of solar evaporative coolers
Authors: Murodov J N
Published: December 2022

The metrological characteristics such as the temperature and relative humidity of the cooled air in solar evaporative coolers in the form of an umbrella or awning are experimentally investigated in the work. Hygroscopic material was used for evaporative cooling. The results are compared with the data obtained from the waterproof material. They allow us to conclude that solar evaporative cooling is promising as an ecologically pure method for cooling air in open areas under canopies.
Characteristics of anisotropic media over hydrocarbons in the mode of frequency-modulated signals
Authors: Yanushkevich Viktar F , Dauhiala Dzmitry A , Maladzechkina Tatiana V , Kalintsau Siarhei V , Bogush Vadim A
Published: December 2022

The article considers the impact of frequency-modulated signals on an anisotropic medium over oil and gas deposits. Modeling of the components of the tensors of the dielectric constant of the medium over hydrocarbon deposits was carried out. The characteristics of the medium over accumulations of hydrocarbons for frequency-modulated signals from the frequency of the carrier oscillation, the frequency modulation index for the right and left polarizations of electromagnetic waves are studied. Methods of searching for hydrocarbons based on the variation in the characteristics of the applied signals are recommended. It is proposed to introduce new search modes to improve the accuracy of determining the boundaries of hydrocarbon deposits. The influence pattern of the dielectric constant of an anisotropic medium on the real and phase components of the tensor components are established. The research results can be applied in the electrical exploration of minerals.
Using a training stand to gain skills in measuring FOCL parameters
Authors: Dmitriev Alexey , Shibaeva Margarita
Published: December 2022

This article is devoted to the problems of engineering education in a technical higher educational institution. In particular, obtaining an insufficient amount of practical skills and abilities in the field of systems, networks and telecommunications. This article discusses the acquisition of practical experience in the measurement of various parameters of fiber optic communication cables using measuring instruments to control the fiber optic line. For a visual demonstration of the possibility of carrying out laboratory work on this stand, the identification of the influence of connectors at the ends of fiber-optic patch cords on the operation of the line is considered. All this became possible thanks to the creation of a training stand, which is designed to train students in the specialty “Infocommunication Technologies and Communication Systems”, and the like.
Computational model “herd of herbivores & flock of predators” in scope of global optimization problem
Authors: Rodzin Sergey , Rodzina Lada , Rodzina Olga
Published: December 2022

The article proposes a coevolutionary computational model “a herd of herbivores – a flock of predators”. The selfish behavior of individuals of a herd of herbivores being attacked by a pack of predators is modeled. Attractive operators of patterns of individual and collective behavior of agents, as well as mechanisms of population selection, are considered. The results of a series of experiments with the model “herd of herbivores – a flock of predators” for the problems of finding a global minimum in known test functions are presented, as well as a nonparametric proof of the statistical significance of the results obtained using the Wilcoxon signed-rank test.
Mathematical methods for evaluating the performance of microcontrollers for automation of production in mechanical engineering
Authors: Shamlitskiy Yaroslav I , Popov Anatoly A , Rogova Daria V , Saidov Nazar V , Yu Efimov Alexey
Published: December 2022

This paper examines the influence of microprocessor technology on the current situation in the machine-building industry, and also provides evidence of the high efficiency of the use of microcontrollers (MSU) in mechanical engineering. A comparative analysis of existing microcontroller families on the market is carried out, where the distinctive features of each family and their applicability in the modern realities of mechanical engineering are presented.
Combining Euler series and series from continuations of the Bernoulli scheme
Authors: Afanasyev Vladimir V , Solovyeva Alla A
Published: December 2022

This article describes a new approach to constructing numerical series which converge to an irrational number, a two series combination being proposed. The first series is constructed from the probabilistic interpretation of summing numerical series, which is the authors’ continuation of the Bernoulli scheme. Our ideas are based on the rejection of finiteness and independence of trails. A probabilistic urn model allows us to get a convergent numerical series as well as a series coinciding with the elements of Leibniz harmonic triangle diagonals. The second series used in the considered approach is presented by different Euler series which are extensions of the Basel problem. The combination of two numerical series makes it possible to sum unknown numerical series in closed form. A new reading of the Leibniz harmonic triangle and Euler series variations as well as an approach to finding probabilistic urn models of the summing series are proposed. It is symbolic that the paper considers the ways of connecting the “Basel series” and the series obtained from the continuation of the Bernoulli scheme taking into account that Jacob and Johann Bernoulli worked at the University of Basel. The adoption of the method of combining two numerical series enables to obtain results which have not been previously published in scientific literature.
Acousto-optical modulation of airy light beams in crystals
Authors: Kulakov Sergey V , Kulak Gennady V , Shakin Oleg V
Published: December 2022

The non-collinear diffraction of Airy light beams on ultrasound in the regime of weak and strong acousto-optical (AO) interaction is investigated. Expressions are obtained for the complex amplitudes of diffracted waves in the general case of an anisotropic medium. It is shown that with an increase in the dimensionless parameter of the Airy beam, the efficiency of Bragg diffraction decreases. At the same time, however, the shape of the modulation curve remains unchanged. It is established that the greatest efficiency of anisotropic Bragg diffraction is achieved for a case when the diffracted Airy beam propagates along the front of the ultrasonic wave. It is shown that the efficiency of AO diffraction of Airy beam on an amplitude-modulated wave is determined by the diffraction efficiencies of constant components in a diffracted beam.
Cosserat’s theory for quality assessment processes for filamentary additive manufacturing products
Authors: Chabanenko Aleksandr , Kurlov Victor
Published: December 2022

Computer modeling of the behavior of materials is very important for the development of additive technologies at the present stage. This article is devoted to a review of models that can and should be used for numerical modeling of material deformation as applied to additive technologies in the process of layer-by-layer synthesis, as well as an exposition of the Cosserat elastoplastic model, the rationale for its application for modeling plastic deformation in structurally inhomogeneous materials such as polymers for additive manufacturing.
Investigation of the microstructure evolution during the broaching in step-wedge strikers by computer modeling in the deform software package
Authors: Volokitin Andrey , Naizabekov Abdrakhman , Panin Evgeniy , Tolkushkin Andrey
Published: December 2022

In this work the forging process in step-wedge strikers by commercial FE-code Deform was simulated. For microstructure evolution the Cellular Automata method was used. The influence of technological and geometric parameters of the forging process on the microstructure evolution was studied. Models with different values of the joint angle of the wedge and depression faces, the friction coefficient at the contact of workpiece and tool, the upper striker movement speed and the workpiece temperature were considered. As a result, the following optimal geometric and technological parameters were determined: the junction angle of wedge and depression faces is 160°; the friction coefficient is 0.7; the upper striker movement speed is 1 mm/s; the workpiece heating temperature is 1000°C.