Objective.  The aim of the study is to consider the methodology for calculating a thermoelectric unit as part of a thermoelectric system (TPS) intended for thermal exposure in medical practice, as well as the results of a numerical experiment carried out using it.

Method. The calculation model of the thermoelectric block, which is part of the system for conducting thermal physiotherapy procedures, is described. The model is built on the basis of standard expressions for calculating the electrical and geometric parameters of thermoelectric modules (TEM) depending on the thermal and electrical parameters of thermoelement (FC) materials, heat and cooling capacity values, and characteristics of heat removal systems from FC hot junctions.

Result. According to the calculation model, the thermoelectric unit was calculated, which is part of the system for conducting thermal cosmetic procedures, developed in the laboratory of semiconductor thermoelectric devices and devices of the Daghestan State Technical University on the temperature difference between the junctions for different values of the supply current, as well as the dependence of the voltage on the TEM on the magnitude of the supply current at different values of the temperature difference between the junctions, the change in temperature at the cold junction and the power of the TEM on the supply current. The graphs are calculated at a hot junction temperature of 320 K.

Conclusion. As a result of calculations, it was found that the operating power range of TEMs of the TV-127-1.4-2.5 type is in the range from 8 to 17 W with an average temperature difference between the junctions of 45 K. In this case, the supply current will be 1 .5-3.5 A with a power consumption of 20 to 80 watts. The refrigerating coefficient varies from 0.1 to 0.5. In accordance with the tasks to be solved, the thermoelectric unit of the device should include four TEMs of this type. 

Objective. The aim of the work is to determine the thermodynamic efficiency of the modernized refrigeration unit of a household refrigerator compared to the basic model using the entropystatistical method.

Method. В ходе работы при проведении исследований применен научный метод системного анализа, а также энтропийно-статистический метод термодинамического анализа при определении эффективности холодильного цикла бытового холодильника.

Result. The analysis of the distribution of energy costs to compensate for the production of entropy by the nodes of the refrigeration unit is carried out. This analysis allows us to visually assess the energy losses in the cycle of a household refrigerator. The analysis was carried out for the most popular refrigerants R134a and R600a when used in household refrigerators. Based on the calculations carried out, comparative diagrams of energy losses in cycle processes are constructed. The entropy-statistical analysis of the thermodynamic efficiency indicators of the cycle confirms the advantages of the modernized refrigeration unit of the household refrigerator.statistical method.

Conclusion. In the course of the work, it was confirmed that the use of an upgraded refrigeration unit will reduce the total energy costs, and the chosen research method will visually assess the energy losses for the elements of the refrigeration unit cycle. 

Objective. The article proposes design solutions aimed at the comprehensive modernization of the cold supply system of the ice palace "Puck" in Sochi, to reduce its impact on the environment.

Method. A water reuse system has been created and a technology has been developed for using low-temperature heat that is released during the operation of the refrigeration machine.

Result. A refrigeration plant has been developed that allows you to utilize, accumulate and direct the heat of condensation for the secondary use of thermal energy by other engineering systems at the facility, thereby reducing heat and greenhouse gas emissions into the Earth's atmosphere and increasing the technological capabilities of cooling.

Conclusion. The proposed methods make it possible to make the necessary calculations and select equipment for the implementation of the developed systems in ice arenas.

Objective. The aim of the study is to develop a mathematical model for determining the temperature field of a human eyeball under thermal influence on its anterior segment.

Method. A mathematical model has been developed to determine the temperature field of a human eyeball when exposed to its anterior segment.

Result. The temperature dependences of characteristic points inside the eyeball on time during cyclic exposure to heat flow on the anterior segment are obtained, as well as graphs of temperature distribution along the optical axis of the eyeball when applying heat flow.

Conclusion. The developed mathematical model allows us to take into account the thermophysical characteristics of all the main structures of the human eye, and also shows the effectiveness of temperature massage of the ciliary body and lens. 

Objective.  The article discusses the issue of creating an infrastructure solution that allows, on the basis of modern information technologies, to organize a fault-tolerant videoconferencing server in the judicial system. The choice of technologies was determined by the need to use a video conferencing server in multi-user mode, as well as the convenience and ease of administration. The use of virtualization for the videoconferencing server will allow flexible functioning of both the system as a whole and all its components, isolate the use of resources, and configure monitoring to monitor the behavior of the system. The advantage of the solution presented in the article is its cost, which will be expressed only in the presence of a server grouping or its lease (instead of a monthly or annual fee to commercial organizations). Also, the advantages include the presence of an engineer of an average level of preparedness in the staff structure of the organization. 

Objective. This paper considers protection against threats that occur more often in the period from the start of the operating system boot. Consideration of various configurations will allow an overview of a fairly wide range of situations that arise. To solve the problem, it is necessary to determine the vulnerabilities, as well as to designate the coefficients that determine the state of the automated system.

Method. Computer facilities are a set of software and hardware components (including information security tools) of data processing systems that can function independently or as part of other systems. Methods for analyzing the process of the impact of computer threats at the stage of loading the operating system are applied.

Result. A technique is proposed for calculating the security factor of automated systems in a secure design, depending on the availability of the necessary security policies and the timely updating of virus and threat signature databases. The vulnerabilities in the process of starting the operating system are summarized, conclusions are drawn on the calculation of the security level coefficient of the automated ATS system based on the information security of the information security system with updates of virus and threat signatures.

Conclusion. The developed methodology makes it possible to assess the security of automated systems, taking into account the situation of information security in the field. 

Objective. The aim of the study is to develop a model for the erosion of noncohesive soils that are heterogeneous in size in river beds.

Method. The mathematical model was developed using the theory of probability and the theory of outbursts of random processes, taking into account the normal law of distribution of the horizontal and vertical components of the instantaneous flow velocities and the Rayleigh law for the distribution of their maxima.

Result. Statistical analysis of various models of erosion of non-cohesive soils heterogeneous in size in river channels was performed.

Conclusion. The basic principles of studying various models of erosion of heterogeneous noncohesive soils in river beds, as well as the structure of calculation algorithms and programs compiled on its basis, allow us to continuously improve the calculation method and make adjustments to the corresponding modules of algorithms and programs.

Objective. The purpose of the work is to increase the efficiency of the process of task allocation through preliminary decomposition and prioritization of tasks based on the process of collective decision-making (CDM) in swarm robotic systems (SRS).

Method. Task decomposition implemented using a hybrid decision-making strategy, the majority principle of changing opinions using distributed registry technology for disseminating opinions among SRS agents and aggregating accumulated knowledge about the functioning environment. An element of scientific novelty is the proposed SRS procedure, which provides the possibility of assessing the priority of tasks, which in turn improves the efficiency of the SRS agents.

Result. Software implementation of the proposed method made in the C++ programming language. For the experiments, the scenario of collective perception by SRS agents in a specialized simulation environment ARGoS was used.

Conclusion. The method implemented using the solutions proposed in the work turned out to be more efficient than the method based on the greedy algorithm. The proposed solutions can be used not only in SRS, but also in any other robotic systems with decentralized control, designed to monitor and control environmental parameters.

Objective. The purpose of the study is to analyze modern information security technologies for solving the problems of protecting information in the enterprise infrastructure.

Method. The study is based on the methods of system analysis, synthesis, deduction.

Result. The analysis was carried out and the features of information protection technology were disclosed for the purpose of possible use in the infrastructure of the enterprise. The analysis of domestic and foreign software for practical use is carried out.

Conclusion. The results of the analysis reveal the features of using information protection tools in the enterprise infrastructure in order to counteract modern vectors of attacks on information resources. 

Objective.  In the modern world, innovative technologies are actively developing, communications are moving into the Internet space. Nevertheless, new technologies turned out to be in demand in the segment of organizations, individuals, cyber fraudsters and hackers. The purpose of the study is to analyze the essence and structure of modern social engineering, including reverse social engineering in the context of the digitalization of society.

Method. Adapting the study to the current moment, it is clarified that technologies, developments and manipulative sociological tactics are picked up not just by hackers, but also by followers of radical ideas.

Result. The optimal definition of the term "social engineering" is proposed - the identification and exploitation of incompetence, insufficient professional level or negligence of employees of an organization or individuals to obtain unauthorized access to confidential data; a set of technologies based on the use of the psychological specifics of a person.

Conclusion. The novelty of the study lies in an in-depth study of the classification of types of attacks using social engineering methods and recommendations for countering and preventing them. 

Objective.  When solving a scientific problem related to assessing the security of automated systems of internal affairs bodies, in particular, when developing a methodology for quantifying protected automated systems of internal affairs bodies, the first stage of the solution is the analysis of international, Russian, as well as departmental legal documents on information security ( IS) of automated systems of internal affairs bodies of the Russian Federation (AS ATS of the Russian Federation), based on the results of the analysis of which it is necessary to develop a methodology for quantifying the level of security of the ATS of the Russian Federation.

Method. In the course of the work, an analysis was made of international, Russian, as well as departmental legal documents on information security of the ATS of the Russian Federation.

Result. An exhaustive list of literature has been obtained, including international, Russian, as well as departmental legal documents on information security of the RF ATS AS.

Conclusion. An analysis of international, Russian, as well as departmental legal documents on information security of the ATS of the Russian Federation showed that the documents on the protection of information of the ATS of the Russian Federation, as well as the methodology for quantifying the level of security of these systems, have been developed insufficiently, in particular, they are absent a system of indicators, as well as mathematical models and algorithms for assessing the level of security of the ATS of the Russian Federation, which requires significant improvement of these documents. 

Objective. The aim of the study is to develop a mathematical model and numerical methods for finding the equilibrium composition of a thermodynamic system.

Method. To find the equilibrium composition of the thermodynamic system, a combination of numerical methods was used: Lagrange, Newton–Raphson and Gauss.

Result. The analysis of existing software systems and numerical methods used in them for the calculation of thermodynamic systems is carried out. Based on the analysis, practical implementation attempts, it was possible to develop a mathematical model consisting of numerical Lagrange methods (allows you to move from a conditional problem to an unconditional one); Newton–Raphson (an approximate method for solving a nonlinear system of equations); Gauss (solving a linear system of equations). For the convergence of the Newton–Raphson method, the required quantities were replaced by their squares, and ranges of variation were set for each quantity. The results of comparing the calculations of the equilibrium composition with the Terra program show satisfactory results.

Conclusion. The T-Energy software package allows you to calculate the equilibrium composition for a thermodynamic system. 

Objective. Improving the quality of detection and stego-detection of latent images embedded in the protected object of intellectual property by various methods.

Method. The method for stego-detection of latent images based on deep learning is proposed. The method is based on the use of the VGG16 convolutional neural network model, in which the architecture and training parameters are optimized.

Result. Increasing the accuracy of detecting stegocontainer images by 3.8%, as well as the possibility of using the algorithm of the developed method for images with a higher resolution than the dimension of the input of an artificial neural network.

Conclusion. The developed method is intended for stegan detection in two cases: to detect the fact of illegal use of intellectual property objects;  for use in computer forensics when identifying images containing hidden and prohibited information.

Objective. The article is devoted to the actual problem of minimizing the designer's work time using Dynamo Studio as a powerful tool for automating design tasks.

Method. A description of some of the possibilities of the Dynamo Studio visual programming environment when developing a building project in the Revit software package is given.

Result. Dynamo scripts work methods are presented and described, which allow to significantly speed up the processes of modeling and preparation of project documentation. The principles of information modeling make it possible to increase the speed of the project work being carried out without adversely affecting its quality. This makes it possible to avoid a wide range of design errors, which in the future will not lead to corresponding problems during the construction phase of the facility. The results of the application of the developed algorithms for the automated construction of a three-dimensional model of a multi-storey building are presented.

Conclusion. Using the visual programming environment allows you to create an information model that updates its configuration when the elements included in it change. 

Objective. The study is conducted in order to identify the most valuable metrics for mobile application analytics and evaluate its effectiveness; consideration of the state and development trends of the mobile application market in the Russian Federation; determining priority areas for evaluating the effectiveness of mobile applications.

Method. To achieve this goal, methods of analyzing promising scientific sources in the field of mobile application development are used, and development trends in this area in the Russian Federation are considered, taking into account political and social phenomena. This allows us to highlight the cause-and-effect relationships of the position of the direction of mobile application development in the market of the Russian Federation, as well as to identify promising evaluation criteria for the effectiveness of mobile applications. The information obtained allows us to consider the problems of developing mobile applications from a new point of view. To evaluate the effectiveness of performance indicators, methods of comparative analysis of mobile application data are used.

Result. The results of the analysis of scientific sources are presented, the main evaluation criteria for the effectiveness of mobile applications are identified, their structuring is carried out, and the relationships between them are highlighted.

Conclusion. The performance indicators considered in this study are applicable for predicting the competitiveness of mobile applications and assessing their attractiveness to users. It should be noted that in order to successfully measure the effectiveness of mobile applications, it is necessary to take into account the evaluation criteria that are important for a particular product in the aggregate. This makes it easier to identify aspects of mobile applications that need to be changed and modified.

Objective the purpose of these studies is to choose the optimal design solution in the design of double-hinged wooden frames with a metal-wood crossbar, based on a comparative analysis of the stress-strain state of a metal-wood crossbar in the form of beams of various shapes, determined by the results of theoretical studies and numerical experiment.

Method. Determination of the stress-strain state of metal-wood beams using theoretical studies and numerical experiment performed in the computer complex PC "LIRA".

Result. Optimal design solutions of metal-wood crossbars of double-hinged frames in the form of reinforced beams of various shapes are proposed.

Conclusion. The bearing capacity of double-hinged frames with a crossbar in the form of reinforced glued wood beams is on average 35 - 38% higher than the load bearing capacity with a crossbar in the form of un­reinforced glued wood beams.The use of metal-wood (reinforced) beams makes it possible to optimize the cross-section by reducing the cross-section height, thereby saving up to 40% on wood material.

Objective. The purpose of the study is to substantiate the need to take into account the geometric and physical nonlinearities in large-span membrane-pneumatic systems.

Method. The study is based on the application of the parameter variation method; method of successive loadings; the iterative method of parameter increments using the third Euler-Cauchy numerical procedure or the Runge-Kutta method of a higher order of accuracy.

Result. It has been established that the geometric non-linearity can be from 5 to 10% if the structure has a small or medium span, and the load on the structure is not very large, especially when it comes to section load. If the span of the structure is 120150 meters, and the load and deflections are large enough, then the geometric nonlinearity can be 20% or more. It was revealed that the physical nonlinearity, which we took into account by the standard Euler-Cauchy procedure of the third order of accuracy, with a large span of the structure and a large load is approximately 13-21%, and the part of the physical nonlinearity of the air pumped between the hermetic membranes of the structure is determined using an improved formula Euler-Cauchy with the number of iterations 20-25, i.e. "aftereffect", according to the results of the study, ranges from 2-7%.

Conclusion. A structure consisting of light metal structures can be erected within a few months on a finished pile or strip foundation. Such structures can easily withstand many types of dynamic loads, namely wind, seismic, vibration, and are one-third cheaper than buildings made from traditional materials. 

Objective. The aim of the study is to determine the dependence of the normal stress on the radius of curvature of a flexible rod at different thicknesses.

Method. A method was applied to determine the maximum stresses in a longitudinally compressed rod of high flexibility using elliptic integrals.

Result. Modeling of a thin-walled longitudinally compressed rod was performed in the ANSIS calculation complex.

Conclusion. The exact theory for calculating flexible rods allows you to determine the value of the axial force during longitudinal compression, at which the ends of the rod will close. When solving the problems of practical use of this type of rods, it is of interest to determine the maximum stresses, and at any stage of deformation, which makes it possible to choose the dimensional parameters of the elastic element and its material with greater accuracy. 

Objective. Development of a methodology for determining the allowable loads on existing structural elements, the design model of which is a flexural-rigid thread, based on the requirements of strength and rigidity due to the changed operating conditions of structures.

Method. This study is based on mathematical modeling of the problem of conditional optimization. The objective function is the total potential energy of deformation of a thread with some flexural rigidity. In this case, restrictions are imposed on strength, rigidity, and the condition of continuity of deformations. At the same time, to achieve this goal, the provisions of the strength of materials, as well as the apparatus of integral and differential calculation of functions of one or more variables, were used.

Result. An assessment of the adequacy of the results obtained using the developed methodology was carried out. A numerical experiment was performed to determine the value of the allowable uniformly distributed load and the corresponding distribution of stresses and strains along the length of a thread of finite stiffness with given physical and geometric parameters. It has been established that the discrepancies in the values of the results obtained using the proposed modeling technology and the commercial computer-aided design and calculation system LIRA 10.8, implemented on the generally recognized finite element method, are no more than 5%.

Conclusion. The developed technique allows setting and solving problems of determining the ultimate loads on flexural-rigid threads, based on the allowable stresses and strains, in contrast to existing commercial computer simulation systems that solve exclusively direct problems of determining the stress-strain state of various types of structures. It can be used at the stage of inspection of large-span coatings in the reconstruction of public buildings and engineering structures. 

Objective. In order to improve the control system of an air heat pump and increase its efficiency, it is necessary to take into account as accurately as possible all the elementary stages of the processes occurring in the system under consideration. The article discusses in detail the heat and mass transfer process of evaporation of the refrigerant from the boiling working fluid of a heat pump.

Method. Description of heat and mass transfer processes occurring in the evaporator line of an air heat pump.

Result. A numerical experiment was carried out to determine the size of the refrigerant droplets that can fly out of the boiling freon liquid during the operation of the heat pump. The calculations performed showed that droplets with a diameter of less than 1 mm have time to evaporate in the vapor flow during the movement from the boiling zone to the droplet eliminator located in front of the compressor.

Conclusion. Research will make it possible to develop recommendations for the design of the droplet collection unit, as well as to develop models for optimizing the operating modes of air source heat pumps. 

Objective. The article proposes a method for finite element analysis of pipe-concrete columns in a physically nonlinear setting by reducing a three-dimensional problem to a twodimensional one based on the hypothesis of plane sections.

Method.The equations of the theory of plasticity of concrete by G.A. Geniev are used. The technique was tested by comparing the solution with a calculation in a three-dimensional setting in the LIRA-SAPR software package, as well as with the experimental data of A.I. Sagadatov and calculation according to the current Russian design codes for steel-pipe concrete structures.

Result. It has been established that the effective area of operation of columns with a circular cross section is small eccentricities of the longitudinal force.

Conclusion. The proposed approach can be applied to the analysis of the stress-strain state and the bearing capacity of pipe-concrete columns of arbitrary section. There are no restrictions on the composition of concrete, and the shell material can be not only steel, but also fiberglass. 

Objective. The purpose of the study is to prove the features of the operation of largespan flat structures, which are also taken into account in their design.

Method. A technique is presented that makes it possible to reduce span bending moments. Examples of rational design of beam trusses are given.

Result. The given structural diagrams, as well as the analysis of their work, allow designing large-span flat systems in the form of frame and arch structures, which have high reliability, minimal weight, and high manufacturability in manufacturing, transportation and installation.

Conclusion. The presented structural schemes, sections and junctions of elements are used in the practice of design and construction. Rational design solutions make it possible to reduce the own weight of flat largespan structures, frames and arches due to the optimal choice of their design and design schemes.