The development of an automatic system for installing a magneto-optical magnetic field sensor in a neutral position has been carried out. Installation in the neutral position is carried out by an automatic piezoelectric drive control system based on a microcontroller. A mathematical model is constructed and numerical simulation of the automatic control system is performed. The results and parameters of the simulation are presented. The developed system provides a significant increase in the autonomy of the sensor, which makes it possible to eliminate or significantly reduce the cost of regulating the sensor.

Keywords: magnetic field sensor, magneto-optical sensor, automatic control system, piezo motor

For the possibility of installing overhead cranes, steel columns of an industrial building are made in steps, with the allocation of crane and crane parts. The basis of the upper and lower parts of the column are steel I-beams with a mismatch of the central axes. As part of the work, variant modeling (using CAD) of a steel column that is part of the U-shaped frames of industrial buildings, consisting of crane and crane parts, was carried out. Various solutions for the difference of the central axes of the crane and crane parts of the column in the model are proposed. The results of static calculation of column elements are obtained. A comparison of the results obtained is made, an analysis of the optimal method of modeling column elements for structural schemes is performed. Based on the calculations performed and the analysis of the results obtained, conclusions are drawn.

Keywords: industrial building, I-beam, finite element method, stress-strain state, node, rod, circuit

In the article, the authors examine the problem of ensuring cybersecurity in the modern world in terms of the study of social practices. The implemented cyber attacks are analyzed, and the danger of hacker attacks is shown. With a fair amount of evidence, it can be stated that in the modern world, the risks associated with cyber intrusions can include the loss or disclosure of consumer data, theft or disclosure of intellectual property, as well as the loss of investors as a result of the theft of funds or a decrease in the market value of companies subjected to cyber attacks. It is concluded that cybersecurity is a constantly evolving landscape, and now there is an urgent need to constantly learn from both our own experience and the experience of other companies countering cyber attacks effectively, and it is also important that successful interaction with adversaries in cyberspace requires a constant pursuit of a tactical, operational and strategic initiative.

Keywords: cyber wars, cognitive modeling, cyber attacks, hacker attacks, cyber risks, cyber defense

The article considers the process of relaxation of fibrous material after the action of the load on it is completed. A simple model of the relaxation process is constructed in the form of an exponential function, which describes this process quite accurately. It is determined that the relaxation time estimates are robust with respect to the parameter distributions. The constructed relaxation models make it possible to estimate the magnitude of the residual relative strain corresponding to the plastic strain of the material.

Keywords: relaxation, deformation, fibrous material, robustness, Monte Carlo method, exponential model, regression

The concept of a fibrous material (hereinafter referred to as FM) as a soft structure formed by fiber elements surrounded by air and areas of fiber interaction on touch surfaces is proposed and substantiated. The fiber elements are in a deformed state. The deformation of the fibers is reversible, elastic-elastic. In the areas of interaction between the fibers, the forces of adhesion and dry friction act. The deformation of the fibers leads to the preservation of residual internal energy in the material. At low loads, the FM can change its state reversibly. At high loads, the structure of the interaction sites irreversibly changes. The processes of aging and degradation of FM are gradual irrevocable transitions from one group of states to others. The dynamics of these processes is statistical in nature. Therefore, a Markov model of state change has been developed in the form of several subsets of irrevocable subsets and one ergodic subset of states. At the qualitative level, the possibility of using the proposed model to describe the dynamics of FM aging processes and estimate the duration of this process, taking into account its probabilistic and statistical nature, is shown.

Keywords: fibrous material, aging, soft structure, elasto-elastic deformation, irreversible process, markov model, statistical dynamics

In a competitive environment, the definition of an effective strategy for the development of a company acquires great importance and is impossible without the use of mathematical modeling methods. The article proposes a hierarchically organized model of an IT enterprise. The consideration was carried out on the example of Electronic Medicine LLC. The Cobb-Douglas production function is used to describe the firm's activities. Numerical calculations are made by simulation for real input data. The Stackelberg equilibrium is constructed, and the results obtained are analyzed.

Keywords: hierarchical modeling, Stackelberg equilibrium, Cobb-Douglas production function, simulation

The results of a study of the effect of hardening the roof of workings of small length, of arbitrary shape, with a cross section of up to 80 m2, with advanced anchoring, which can significantly reduce the displacement of soil outcrops, are presented. The analysis shows that it is not possible to completely eliminate soil fallouts; therefore, a complex of studies of a stress-strain (SSD) soil mass, reinforced with a protective screen, was carried out. Finite element modeling (FEM) has established that advanced anchoring up to 15 m long does not work effectively, since the anchors are located in the zone of soil slippage. Increasing the length of the protective screen anchors to support their ends outside the sliding prism makes it possible to increase the stability of soil outcrops in the face.

Keywords: underground construction, stresses, displacements, hardening, anchoring, modeling, finite element method

This article analyzes the problems of spatial, temporal and phase synchronization in non-cooperative passive bistatic radar coordinate meters, which make it difficult to detect weak objects. The method of time and phase synchronization based on the estimation of the parameters of the direct wave signal and the method of detecting weak objects, which consists of a long coherent accumulation of signal parameters, are investigated. A universal algorithm is proposed, which consists of two stages: extraction of direct wave pulses and parameter estimation. Based on the estimation of parameters and waveform, an algorithm for detecting weak targets based on the generalized Fourier transform is given.

Keywords: non-cooperative passive bistatic radar, algorithm, synchronization, pulse, generalized Fourier transform

The search for orthogonal and quasi-orthogonal matrices is considered as a sequence of setting initial conditions, choosing an implementation method, filtering a set of generated sequences. It is proposed to accelerate the search for matrices by pre-fixing their structure and filtering the generated sequences using the Fourier spectrum. Fixing the structure involves using the symmetry properties of the desired matrices. Filtering allows you to exclude sequences with explicit spectrum outliers when forming blocks of symmetric matrices.

Keywords: mining of matrices, Hadamard matrices, Propus conctruction, filtering sequences

The main maintenance of a diversification of production as activity of subjects of managing is considered. being shown in purchase of the operating enterprises, the organizations of the new enterprises, redistribution of investments in interests of the organization and development of new production on available floor spaces. The most important organizational economic targets of a diversification of management are presented by innovative activity of the industrial enterprise.

Keywords: ideal thread, flexible homogeneous inextensible thread, tension, balance of thread balance, balance on a smooth surface, balance on a rough surface, sag arrow

The article presents a method for calculating short-circuit currents in a DC traction network. The system of group grounding of supports, considered in the article, is equipped with an additional conductor that improves the working conditions of the entire section of the electrified railway by reducing the resistance of the short circuit loop.

Keywords: group grounding of supports, short-circuit current, electrified railway, traction network, fiber-optic communication line.group grounding of supports, short-circuit current, electrified railway, traction network, fiber-optic communication line

The article describes the study of the behavior of the reaction vector in the contact spot of the wheel with the support base when the values of the angle of rotation of the driving wheels vary. To find the dependence of the values, a MATLAB Simulink model was created with software blocks that allow determining the behavior of the reaction vector in the contact spot of the wheel with the support base when the values of the angle of rotation of the driving wheels vary.

Keywords: controllability, mathematical model, wheeled vehicle simulation, wheel tire, wheel rotation angle, MATLAB Simulink

The paper analyzes the thermal regime of a highly functional on-board control unit in an AMg6 aluminum alloy case and compares the obtained data with the thermal regime of a unit with a highly efficient heat sink made of composite materials. The calculation of the thermal field of the block was carried out using CAD tools based on the finite element method with a thermal application in order to assess its performance under given boundary conditions. Based on a comparative analysis of various heat-removing materials of the basic supporting structure, the least heat-stressed system was chosen.

Keywords: thermal regime, highly efficient heat removal, composite materials, on-board equipment, oxygen system, finite element method, mathematical model, computer-aided design system, electrical radio product, printed circuit board

The flow that occurs during the movement of an elevator cabin in the shaft of a high-rise building from the -4th to the 58th floor is considered. The moving elevator cabin works like a piston and pushes air in front of it out of the shaft and draws air into the shaft behind it. This effect is especially significant in high-rise buildings, which are characterized by a high speed of elevator cabins movement. The STAR-CCM+ software was used as a research method. To simulate the non-stationary problem of the elevator cabin movement, the technology of sliding meshes was used. It was found that when the elevator cabin moved at a speed of 7 m/s, the maximum pressure drops formed on the surfaces of the elevator shaft amounted to 130 Pa. It was found that the maximum flow rate of air entering the elevator shaft and from the elevator shaft into the hall due to the piston effect is about 250 m3/h. This value is comparable to the flow rates formed due to natural movement of air in the elevator shaft caused by stack effect in winter and cannot be automatically excluded from consideration.

Keywords: high-rise building, numerical simulation, piston effect, stack effect, elevator shaft

To analyze such significant indicator of the locomotive industry as the value of import customs payments, the dependence of the volume of import customs payments on weight, cost, weighted average rate and dollar exchange rate is examined. Mathematical modeling was carried out on the basis of monthly data during the period from 2019 up to 2021 of the volumes of customs payments and their parameters of the Group 86 of the Customs nomenclature of EAEU FEA "Railway locomotives or tram motor cars, rolling stock and their parts; track equipment and devices for railways or tram tracks and their parts; mechanical (including electromechanical) signaling equipment of all types". The interrelations of these variables are represented by a system of simultaneous structural equations. The import substitution trend developing in Russia implies strengthening the development of national industries and, accordingly, pursuing a customs policy that implies support for domestic producers and reduction of import supplies. Thus, it is relevant to determine the impact of various factors on the amount of customs duties levied by the customs authorities on foreign economic activity (FEA) participants in operations involving the import of spare parts and other goods for the locomotive building industry to make the right strategic decisions concerning customs restrictions on imports of goods of this industry.

Keywords: locomotive building industry, mathematical modeling, linear multiple regression, multicollinearity, system of simultaneous equations, identification, structural form of the model, reduced form of the model

Nowadays, the System on Chip (SoC) industry is rapidly developing. One of the objectives of SoC developers is to provide the most efficient communication between computational units. One of the possible solutions is using Networks on Chip (NoC) of various topologies with different routing algorithms. In this paper, a configurable test environment designed for cycle-accurate NoC simulation as part of a SoC, used to provide statistics about network behavior during test process, is presented. The environment is designed to evaluate NoC performance as part of a specific SoC at the development stage, when there is a full or partial RTL description of the system. The environment configuration options, its application area, general scheme and calculated NoC performance characteristics are considered. As a conclusion, an example of using the environment to evaluate the performance of a specific NoC is described in detail.

Keywords: network on chip, system on chip, performance evaluation, verification

A set of data on potentially dangerous asteroids for the Earth is analyzed. According to descriptive statistics, a preliminary analysis and data processing is performed. The correlation between the parameters allows you to identify those that will be used to train the models. With the help of machine learning models, asteroids from the database are classified into hazardous and non-hazardous. Methods of logistic regression, k-nearest neighbors; decision tree and others are used. Using cross-validation, the best method is found, then its optimal hyperparameters are determined. The quality of the classifier model is evaluated by the metrics of completeness (Recall) and its standard deviation, as well as using the error matrix (confusion matrix) and the average absolute error in percent (MAPE). The results of analysis and modeling in Python are presented, demonstrating the high accuracy of predicting the resulting model.

Keywords: machine learning, predictive model, data analysis, imbalanced data, logistic regression, k-nearest neighbors, decision tree, random forest, support vector machine, cross-validation

This paper presents a simulation of the vibrations of a membrane in the form of a rhombus. Partial solutions of the problem of free vibrations of a membrane with different initial conditions are obtained and the natural frequencies of vibrations are found. The result obtained can be used to strengthen the structural elements of aircraft with a cellular diamond-shaped structure, as well as in the design of unmanned drones of the flying wing type.

Keywords: free vibrations of a membrane, a membrane in the shape of a rhombus, natural frequencies of vibrations

CFD modeling seems to be one of the most accessible and accurate ways to calculate the characteristics of flow processes using computational and physical-mathematical methods in solving practical problems today. In particular, it is used to determine the parameters of the indoor microclimate. This article describes the process of modeling the operation of hydraulic heated towel rails in the bathroom of a residential building and selects the optimal configuration based on the data obtained as a result of the calculation in the STAR CCM + software package.

Keywords: CFD modeling, building hot water supply, heated towel rail, heat flow, heat transfer, heat transfer, indoor climate, thermal analysis, SolidWorks, STAR CCM+

The paper analyzes the output parameters of field-effect transistors with a contact gate (controlled junction (p-n junction or Schottky gate)) both from modern highly mobile semiconductors (such as AIIIBV, AIIBVI, etc.) and semiconductors such as Si, Ge. It is shown that when the span regions are reduced to micro- and nanoscale values and conditions for the action of strong electric field strengths arise, it is necessary to take into account the dependence of carrier mobility on this field. Comparative analyses of the obtained results with the classical known ratios are carried out.

Keywords: effective mass, drift velocity, electric field strength, mobility of charge carriers, kinetic energy, current-voltage characteristic, field-effect transistor, sub-gate drift region, threshold field of the Gann effect, saturation field strength

The article provides an overview of wearable devices that improve the quality of user recognition of objects of the surrounding world, reveals the process of developing an intelligent module for recognizing objects of urban infrastructure for "sound glasses" - a device designed for blind users. The functionality of the module under development, its architecture is characterized, the process and results of neural network training for object recognition are described, and an algorithm for identifying the color of traffic lights is given. The results of testing the developed software module are presented. The software module created in this work is an integral component of a fully functioning device "sound glasses", the use of which will allow people with visual disabilities to get information about events and the surrounding environment and navigate even in an unfamiliar environment.

Keywords: computer vision, neural network, smart glasses, sound glasses, visually impaired, YOLOv5, object recognition

In a market economy, it is required to calculate foundations using methods that will satisfy the requirements of the first and second limit states with the smallest margins, in order to save money. In this study, the analysis of sediments obtained by numerical and analytical methods was carried out. Analytical calculation is presented by the method of corner points according to the model in the form of a linearly deformable half-space and by the method of layer-by-layer summation presented in the form of modified Pasternak, Winkler-Fuss, Pasternak models. The numerical method is presented by the finite element method implemented in the software systems of the PC «Lira-SAPR» and the PC «PLAXIS 3D». As a result, it was found that the minimum discrepancy between the absolute settlement according to the corner point method in comparison with the analytical method according to the Winkler-Fuss, Pasternak, modified Pasternak models is 9.04%, 9.04%, 53.38%, respectively, and in comparison with the numerical method implemented in the PC «Lira-SAPR» and PC «PLAXIS 3D» is 10.49% and 0.52%, respectively. The highest accuracy in comparison with the method of corner points was shown by analytical calculations by the method of layer-by-layer summation in the formulation of Winkler-Fuss and Pasternak, and by the numerical method of calculation performed by the PC "PLAXIS 3D".

Keywords: geotechnics, foundations, «Lira-SAPR», system «Soil», «PLAXIS 3D», foundation sediment, angular point method, slab foundation, mutual influence of foundations, numerical method, analytical method, finite element method

The paper proposes a method for calculating the interval values of the coefficients of the polynomials of the numerator and denominator of the transfer function. An algorithm is presented that describes the sequence of actions performed, which makes it possible to obtain interval coefficients for the study of both linear and nonlinear systems. An illustrative example is given, which shows the calculation of the interval values of transfer functions, both continuous and discrete systems based on the use of the Matlab system.

Keywords: control system uncertainties, robust stability, marine mobile objects, transfer function with interval coefficients

The wastewater generated by the pulp and paper industry contains diverse contaminants such as organic substances, fine suspended powders, and dissolved solids. Currently, integrated treatment technologies are employed, utilizing thin-layer settling tank modules to eliminate solid contaminants. This study presents the outcomes of a comparative analysis of the efficacy of a conventional thin-layer module with flat plates and a modified thin-layer module consisting of two levels of plates, positioned in opposing directions, facilitating the rotation of water flow within the module. Through computer simulation techniques, it is demonstrated that the modified module design can enhance the cleaning efficiency by 8-30% for wastewater flow velocities ranging from 0.0025 to 0.0125 m/s. Additionally, particle trajectories and velocity fields were obtained, which clearly illustrate the direction of the dictating flow and circulation zones within the structure.

Keywords: Wastewater, pulp and paper industry, thin-layer module, module with rotation of water flow, computer simulation of particle deposition.

The article contains an analysis of the shallow elastic spherical shell on a rectangular plan, reinforced with ribs along its contour, under the uniformly distributed load. The problem is solved numerically with the variational-difference method, considering the geometric nonlineaity and the shear deformations of the shell and the ribs. As a result, the dependencies of the critical load on the shell stiffness and the ribs stiffness are obtained.

Keywords: shallow spherical shell, ribbed shell, stability, bending stiffness, geometrical nonlinearity, variational-difference method, critical load