Recognition of radiation from celestial bodies by technical means is an important task in the orientation of spacecraft. For a device that is part of the Earth orientation device, a variant of modeling an electronic signal amplifier received from a pyroelectric sensor is studied. On the recommendation of the developers, the properties of trans-impedance operational amplifiers were studied, and suitable coefficients for the negative feedback circuit were selected. The type of output signal of the model is studied in comparison with the recording of values taken from a real photodetector. The preferred design of the model in the Matlab Simulink environment is shown – a model defined by an electrical circuit using the Simscape Electrical library.

Keywords: simulation of electric circuits, space orientation, photodetecting device, transimpedance amplifier, optoelectronic devices, space instrumentation

In this work, R, L, C - parameters of spiral structures with sizes l and S were determined to obtain artificial chiral substrates. This made it possible, given the parameters of the polarizability of the helical structures αij, to use these features to determine the conducting properties of metamaterials. The basic relationships have been determined (for determining the electrophysical parameters of spirals (left- and right-handed) that are included as chiral inclusions in the metamaterial. An algorithm for calculating conducting structures using the proposed equations is proposed.

Keywords: biological liquid medium, dielectric constant, complex dielectric constant, loss tangent, medium conductivity, frequency response, fluctuation, frequency range, biophysical parameter

The article reveals the results of the work carried out on modeling the dynamic model of the electric drive of the scanning mechanism of the Earth orientation device, which is based on a hybrid stepping motor. The simulation is based on NEMA 17HS3410 motor parameters. A brief description and features of hybrid stepper motors are provided. The simplest model of an electric drive is considered, in which there is a rigidly set moment of force, a moment of inertia of the rotor of an electric motor, and also the moments of dry friction and the moment of liquid friction are taken into account. It is shown how the change in the value of fluid friction affects the general behavior of the mathematical model of a hybrid electric motor. The behavior of a single-pole stepper drive is simulated. The relationship of the value of the moment of force acting on the rotor with the passport characteristics of the investigated electric motor is considered. The possibility of controlling the scanning mechanism based on P- and PI-controllers is estimated.

Keywords: electrodive, Simulink, moment of force, inetria moment, liquid fricton

The paper presents an integrated approach using machine learning methods for choosing a trading strategy on the currency exchange. The presented approach uses the calculation of the linear regression angle coefficient by log return indicators and determination of the BTC/USD currency pair quotes trend in the next period based on the calculated coefficient sign. The feedforward multilayer neural network is used to predict the angle coefficient value in the next ten minute period for the current twenty minute period. The paper proposes a combined approach to the use of machine learning methods for choosing a trading strategy in foreign exchange. The study presents the results of experiments evaluating the practical results of effective and ineffective strategies based on the predicted values ​​of linear regression coefficients.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

The present paper presents studies of friction and wear characteristics occurring in the frictional contact zone when various frictional substances are forcibly introduced into the active contact zone by the method of molecular dynamics.

Keywords: friction activation, special material, method, quantum-chemical analysis, molecular dynamics, tribology, friction, computer simulation

This article analyzes the development of competition in the transport services market. The development of a competitive transport services market requires creating conditions for exceeding the level of supply of high-quality transport services over demand, as well as ensuring publicity and information openness of the market in terms of prices and quality of services. This will allow consumers to freely choose transport services, make the "price-quality" mechanism work, and make price and quality the subject of competition. Transport communications unite all territorial entities in the region, which is a necessary condition for the unity of its economic space.

Keywords: the transport services market, competition, the safety of passengers

The use of mulcher machines is a promisingmethod of preventing and combating forest fires. Whenpreparing forest areas with the use of mulcher machines the soil is crushed altogether with the vegetation growing on the surface, roots and otherwood inclusions, while the process of interaction of the working body with the soil requires significant energy costs. The analysis of the mulcher operating modes with a working body in the form of a drum-chopper has been carried out and, as the result, the operating modes of the mulcher machine have been determined. The mulcher machine operation mode when cutting woody vegetation has been examined. A computer program has been developed to determine the rational parameters and operating modes of the mulcher machine.

Keywords: drum-chopper, combating forest fires, mulcher machine, wood vegetation cutting

In this article, a scheme of an Elevator with weather regulation is proposed and comparative results of a study of the temperature of the return pipeline with and without regulation are presented. An Elevator with weather control adjusts the temperature relative to the outside air temperature, while a heat point with a classic Elevator returns water to the main line with a constant, higher temperature. The estimated savings from the implementation of the event Elevator with weather control in the building of the administrative building No. 10 in physical terms amounted to 71.13 Gcal, and in monetary terms 124,828 thousand rubles. the payback Period of this event was 1.3 years.

Keywords: Elevator, weather control, heating system, controller, pump, valve, sensor, temperature, heat energy, tariff

When determining the locations of compensating devices, it is necessary to make complex calculations that take into account various factors (included in the equations in the form of variables). To get results, calculations are performed repeatedly. Newton's method with coefficients in the form of a Jacobi matrix is widely used. An algorithm for solving the necessary equations by the Gauss method is considered, and the required number of iterations is determined to obtain reliable results.

Keywords: compensating devices, electric power, network state, nodal conductivity matrix, Gauss method, algorithm, Newton's method, electrical nodes, iterations, convergence, algorithm

One of the effective ways to increase the information secrecy of a constellation of low-orbit spacecraft (LVS) is the use of a satellite authentication system (SAS). In order to reduce the time spent on determining the status of the satellite, as well as to increase the fault tolerance of the identification system, in a number of works it is proposed to use the codes of the polynomial system of residue classes (PSCS). This paper presents a methodology for constructing a fault-tolerant authentication system for a spacecraft, which is based on exchange operations implemented in PSKV codes. Using exchange operations, that is, changing the number of informational and redundant bases, it is possible to ensure the possibility of maintaining the operational state of the identification system in the event of a sequence of failures, as a result of which the level of information secrecy of the NSA will not be reduced.

Keywords: satellite authentication system, polynomial system of residue classes, exchange operations, method of building a fault-tolerant identification system

The article provides a brief analysis of the starting processes of electrical devices. The mathematical formulation of the problem of synthesis of starting rheostats is formulated and its solution is proposed. The main condition for optimal starting of electric motors using thermistor rheostats is presented. Optimal diagrams of the starting current and set of revolutions are given. and also, the change in heat losses in the anchor chain. Recommendations on the layout of starting rheostats are given.

Keywords: thermistor rheostat, optimal start-up, thermal start-up characteristic, optimal control problem, DC motor, boundary conditions, speed

This article discusses the problem of increasing the load-bearing capacity of bored piles. The technology of injecting fixing solutions into the ground under the foundations of a two-story building in the city of Azov to increase the load-bearing capacity of bored piles was described.

Keywords: structurally unstable soil, pile Foundation, load-bearing capacity, soil consolidation, silicatization, camouflage broadening, driving piles, bored piles, screw drilling, concreting

The article considers the dynamics of an ion beam in a laser mass – EMAL-2 spectrometer.a numerical model based on the "large - particle" method is Implemented, taking into account the influence of spatial charge fields and the interaction of charged particles with the field of an electrodynamic system. The software package that implements the mathematical model of ion beam motion consists of two parts. The first part is a program written in C++, in which initial conditions are set, the Coulomb interaction between large particles is calculated using the "particle-particle" method, the system of differential equations (1) is integrated using the fourth-order Runge-Kutta method, and the results are recorded and processed. The second part is a script for the FreeFem++ package, which implements the solution of partial differential equations using the finite element method. A series of numerical experiments and their comparison with the data obtained experimentally are carried out.

Keywords: large particle method, laser mass spectrometer, particle-particle method, electrodynamic system, Runge-Kutta method, laser plasma, magnetic analyzer, ion beam, focusing system, triangulation

This article illustrates specifically how to use least squares method (LSM) and sensitivity function to cope with parametric identification problems. The object of this task is BLDC motor. The example of BLDC can justify the application of LSM and sensitivity function method for estimating nonlinear dynamic objects’ parameters, and the application for motor controlling system in particular. The model in the article is conducted by Matlab. The output is a proof to convey that the method used in solving the problem is accurate, and proves the possibility of its application in scientific and engineering field.

Keywords: parametric identification, least squares method, sensitivity function, BLDC motor, electric drive

This article presents the results of the analysis of factors influencing the burner device of heat generators, as well as methods for their selection. The results of an experimental study of the dependence of the efficiency of heat generators on the operating power of burners are presented. Recommendations have been developed for choosing a heat generator and a burner.

Keywords: heat generator, burner device, Gorenje mode, operating power, heat balance