Purpose of research. The article is devoted to the metallographic study of the structure, as well as the elemental composition of the characteristic zones of samples obtained by the method of layer-by-layer construction of an electric arc in a protected atmosphere. The samples for the study were obtained using a mechatronic system with numerical control, which provides positioning of the device for feeding the filler material in the form of a wire along three coordinate axes. The samples were formed on a receiving surface made of steel 3, the material for layer–bylayer construction was alloy steel Sv–09G2S, the electric arc power source was an inverter-type welding machine Cedar MIG–160GDM, the protected atmosphere was a protective gas environment. The layered formation of experimental samples was implemented using the following schemes: in the horizontal plane; in the vertical plane. Preparation for metallographic examination was carried out in accordance with GOST 5639-82 "Steels and alloys. Methods of detection and determination of grain size", GOST R 57180-2016 "Welded joints. Methods for determining mechanical properties, macrostructure, microstructure". The elemental composition of the obtained samples was carried out by X-ray fluorescence analysis using the X-MET 5100 analyzer. As a result of the conducted studies, the presence of voids between single layers in the horizontal plane was revealed; the material of the receiving surface in the root passage zone and the zone of thermal influence have a structure with lower physical and mechanical properties, as well as lower corrosion resistance compared to the material of the receiving surface. The material of the samples formed in the vertical plane has a structure similar in grain size to the material of the receiving surface

Methods. In the course of the work, methods of microstructure research, as well as elemental analysis were applied

Results. As a result of the work performed on this study, it was revealed that during the formation of single layers on the receiving surface in the horizontal plane, the formation of critical defects - voids and "non-vapors" takes place. The zone of thermal influence, the zone of the root passage contains a metal microstructure that has lower physical and mechanical characteristics and corrosion resistance compared to the material of the receiving surface

Conclusion. When forming products by the method of layer-by-layer construction of an electric arc in a protected atmosphere, the following technological features of the process must be taken into account: in order to prevent the formation of critical defects during layer-by-layer construction of layers in a horizontal plane, it is necessary to establish a range of values of the overlap coefficient of layers; in order to ensure the creation of homogeneous metal structures in the fusion zone of the receiving surface and the construction material, as well as to minimize the size of the zone of thermal influence and the root passage zone, it is necessary to build layers using the receiving surface of materials that maximally correspond in chemical composition to the construction material.

Purpose of research. GOST P 55276-2012 applied in the Russian Federation does not regulate concrete data on the choice of this or that procedure under various conditions of welding and standard sizes of the applied pipes, leaving it to the discretion of the consumer. Unlike the procedure of the welding with only low pressure which is well fulfilled and widely applied in domestic practice, the welding according to the procedure with the only high pressure allowing to reduce three times time of a welding cycle is practically not used and specially intended welding machines in Russia are not issued. In this regard this work is devoted to development of the modes of hot tool welding of abutting connections of pipes from polyethylene with a diameter from 90 to 315 mm for SDR 13.6 - SDR 9.0 with the only high pressure, to the choice of possible domestic welding equipment and experimental check of the developed modes.

Methods. In this article for butt welding by the heated tool of pipes from polyethylene with a diameter from 90 to 315 mm, using a design technique, main parameters of welding procedure are determined with the only high pressure. When choosing the welding machine necessary for tube welding of the considered range on welding procedure with the only high pressure, by results of the carried-out analysis of technical datas of domestic welding machines and features of their operation capabilities it is preferred as the welding machine with the hydraulic drive "Native of the Volga Region of SSPT-315". For experimental check of the executed payment of parameters of the procedure of welding under the cyclogram with the only high pressure four joints of pipes with a diameter of 110 mm with thickness of a wall of 10 mm from PE-100 (SDR 11.0) have been welded and visual and measuring quality control of the executed connections and short-term tests of technological samples on axial stretching by the R-50 machine is made.

Results. Mechanical tests of technological samples of all joints of the pipes from PE-100 with a diameter of 110 mm (SDR 11.0) executed on the SSPT-315 welding machine on welding procedure with the only high pressure have shown 100% - ny result of plastic nature of destruction at the size of lengthening from 500 to 600%.

Conclusion. The high quality of experimental joints of pipes from PE-100 assumes a possibility of use of the SSPT- 315 machine for hot tool welding of pipes from polyethylene of everything of the range regulated by technical datas on welding procedure with the only high pressure.

Purpose of research. Experimental determination and analysis of the bearing capacity, deformability and crack resistance of a reinforced concrete floor slab supported on three sides

Methods. Testing a specimen of a reinforced concrete floor slab supported on three sides (loggia floor) by a controlled load simulating the operational one. Measurement of deflections. Analysis and justification of test results

Results. The slab was loaded to a level of 325 kN or 20.1 kPa. This load exceeded the control load by a factor of 1.64 with a safety factor of 1.6, exceeded the design load by a factor of 2.64, and exceeded the standard load by a factor of 3.08. The maximum recorded deflection at maximum load was 3.01 mm in or in span fractions of 0.0009, which is 7.41 times less than the allowable deflection from the standard load - 0.00667 of the span length. The testing has been terminated for safety reasons.

Conclusion. The points that could allow the developing of more economical building structures are: refinement of the design scheme for the operation of structures, the optimal choice of a finite element in the calculation, as well as the gradual inclusion in the sets of rules of methods for calculating building structures based on the theory of structural systems with distributed parameters at critical energy levels.

Resume. The development of the heat pump market ensures the growth of energy prices, the fight against global warming and the stimulation of the growth rates of countries in transition to "clean energy sources". the most environmentally friendly and energy efficient, taking into account the cost of their installation and the impact of air source heat pumps compared to geothermal ones. However, their use in countries with cold climates is limited by the formation of frost on the evaporator unit heat exchanger, which significantly increases their heating capacity and conversion efficiency.

Purpose of research. The purpose of this work is to compare the efficiency of heat pumps with an evaporative circuit heat exchanger manufactured by MITSUI (Japan) and a heat exchanger with a MOVEBIT defroster manufactured by ALTEC (Russia).

Methods. The research methodology is based on large laboratory tests of an evaporator with an oscillatory circuit of the MOVEBIT system (ALTEK - Russia) and an industrial heat exchanger MITSUI (Japan), a graphical analysis of the operation of a heat pump with common evaporators, and a theoretical substantiation of the transformation ratio. To compare the main standardized performance indicators, the transformation coefficient (COP – coefficient of performance) is used, showing the ratio of received energy to applied work.

Results. The analysis of the results of the heat pump operation showed that while maintaining the humidity at a constant level of φ ≈ 65% and lowering the temperature from +10°C to +5°C, a decrease in the heat output of the unit is observed, regardless of the type of MOVEBIT and MITSUI heat exchanger, which is explained by the formation of condensate. With a further decrease in temperature to zero and below, ice forms on the evaporator of the heat exchanger. Taking into account the cost of removing ice on the MITSUI heat exchanger, the transformation ratio of the heat pump unit (HPU) is 2.08. The removal of ice by the MOVEBIT system practically does not require additional costs and the transformation ratio of the installation is 4.45, which is similar to the operation of an air source heat pump at positive temperatures.

Conclusion. Our studies show that the best prospect for de-icing is the application of mechanical oscillations with the use of magneto-constrictive transducers. The COP of the air source heat pump with the MOVEBIT system exceeds the COP of the heat pump with the MITSUI standard evaporator by 2 times at a temperature of 0°C and below.

Purpose of research. The purpose of this work is to develop a mathematical model that generalizes the power characteristics of rollers that affect the compaction process, taking into account changes in the properties of the compacted material. The proposed mathematical model makes it possible to simulate the process of compaction of a material layer with different compaction methods and changes in the properties of the compacted material.

Objectives. To achieve this goal, it is necessary to establish the influence of the parameters of the roller roller, taking into account the sealing method used, on the magnitude of stresses in the zone of its contact with the surface of the material layer. The efficiency of the sealing process depends on the compliance of the stresses in the contact zone of the roller roller with the characteristics of the material, which are determined on the basis of experimental data. Methods. When developing a mathematical model of compaction processes, mathematical modeling methods were used to determine stresses in the contact zone of the roller roller with the surface of the compacted layer. The establishment of patterns of changes in the properties of the compacted material under the influence of load was carried out on the basis of rheological studies, the results of which obtained the dependence of the characteristics of the mixture layer (coefficients of stiffness and viscous resistance) on the acting load. To clarify the obtained results of modeling the effect of load and material properties on the quality of work, experimental studies were carried out on the CRT-RC-H2 model stand, according to the results of which a connection was established between the deformation of the layer and its compaction coefficient.

Results. The proposed mathematical model makes it possible to simulate the process of compaction of the pavement layer when using different rollers and changing the characteristics of the material layer during the compaction process. According to the results of the study, a relationship was established between the quality of the seal (compaction coefficient) and the deformation of the layer under load.

Conclusion. 1. Based on the results of mathematical modeling, analytical dependences have been established for calculating contact stresses in the contact zone of the rigid roller roller with the surface of the compacted material layer.

1. According to the results of rheological tests, the connections between the deformation and the characteristics of the compacted layer of the material under the operating load are established.
2. The relationship between the deformation of the mixture layer and the compaction coefficient of the asphalt granulate layer is established.
3. The presented mathematical model of the compaction process makes it possible to simulate the technology of compaction of layers of pavement.

Purpose of research. Development of an algorithm for constructing 3d scenes of recognized objects from synthesized depth maps in order to improve the speed of real-time image processing.

Methods. The 3d scene construction algorithm is based on the method of stereo image construction using a threelevel fuzzy depth map construction model. At the first level of this model the boundaries of objects are determined using a modified Canny algorithm, at the second level the values of disparity are calculated on the basis of the sum of absolute differences algorithm modified by fuzzy logic methods, and at the final level the gradients of distances from the boundaries of images to the edges of recognized objects are calculated first and then according to the obtained values of disparity at the second and third levels of the fuzzy hierarchical model, the refined values of disparity are calculated, which are used to carry out the analysis of the depth map.

Results. An algorithm for constructing 3d scenes of recognized objects using synthesized depth maps has been developed. It was determined that the proposed algorithm has better performance compared to existing depth map algorithms such as conjugate point algorithm and pyramidal algorithm.

Conclusion. The experimental results showed that the proposed algorithm has a lower complexity compared to the analyzed algorithms (conjugate points and pyramidal). The minimum average execution time of the 3d scene construction operation was about 1-2 minutes, which is almost 120 times better compared to the conjugate point algorithms.

Purpose of research. Nowadays, the automation of the distance learning process or self-study is relevant. However, to increase its effectiveness, there is a need for a personality-oriented approach to the student. The creation of adaptive learning technologies is becoming a priority. Development of a mathematical model of an automated system for learning to play the piano was the purpose of this work.

Methods. The article discusses one of the approaches to modeling educational processes and systems - the cybernetic approach. The use of this approach allows us to consider the model of the educational system from the point of view of internal blocks and their functions, it allows us to identify sets of input and output data and internal relationships of various components of the system. The mathematical model is based on the operations of the algebra of logic and set theory.

Resalts. Based on the cybernetic approach, the article provides a functional diagram of the system, which clearly demonstrates the sequence of actions performed, as well as the flow of various sets of input and output data. The functionality of the blocks is described in the terminology of operators, which determine the sequence and the required number of questionnaire questions to determine the initial knowledge, skills, and abilities of the trainee and his goals, select the most optimal initial training plan, assess progress and adjust the initial training plan depending on the results of the student. For each operator, sets of inputs and outputs are defined. The description of the data shows what information the system must operate in order for it to work correctly and efficiently. Another significant result of the work was the mathematical model of the system obtained as a result of research, which determines the relationship between input and output data.

Conclusion. The cybernetic approach to modeling educational activities, including in the system of additional education, allows you to structure complex logical connections in the educational system, to determine the sequence and options for the system. The model will form the basis of the information system for piano playing teaching.

Purpose of research. The purpose of this study is to develop a method for improving the efficiency of distributed architectures of data processing systems operating in the fog and edge layers of the network. In conditions of high dynamics of both the network infrastructure and the load, the task of forming the architecture of data processing systems is solved regularly (migration of virtual machines, horizontal scalingб etc.) At the same time, the issue of the consumption of the residual resource of computing nodes is practically not considered, while the often used devices have relatively low capacity, and their high workload leads to a reduction in the service life. Therefore, the creation of methods for forming an architecture of a computing device system that is effective in terms of saving a computing resource is an urgent task.

Methods. The main scientific methods used in this study are domain analysis, operations research methods, optimization methods and computer modeling, confirming the feasibility of the main aspects of the developed method. To improve the efficiency of placing computational tasks on the nodes of a network fragment, this paper formulated a multicriteria optimization problem, where each element of the vector objective function corresponds to an individual value of the probability of failure-free operation of a computing device. To obtain estimated values of the cost function, a priori estimates of the late completion of the solution of computational problems by nodes are used, since the resource allocated for solving depends on the allocated time, and the time for solving the problem, respectively, on the allocated computing resource. The value of the cost function is calculated on the basis of approximate a priori estimates, which leads to a positive effect in terms of the consumption of computing resources of devices.

Results. The result of the study is a developed method for improving the efficiency of distributed architectures of data processing systems operating in the fog and edge layers of the network.

Conclusion. The method proposed in this work allows to choose such a load distribution in order to reduce the workload of devices and thus reduce the consumption of computing resources of the devices.

Purpose of research. Development of a method and algorithm of complex analog radio signals filtering and binarization, such as the signal of Automatic dependent surveillance-broadcast (ADS-B), which allows to increase the sensitivity of the receiver of the AZN-B signal and increase the number of correctly detected received messages.

Methods. To solve this problem, the basics of the theory of signal filtering and the theory of fuzzy sets were applied in the work. The proposed method is based on combining signal filtering by known filters and a two-level fuzzy model. The first and second levels of the fuzzy model contain three operations: automatic formation of membership functions, compositional output and defuzzification. Input variables of both levels are given by trapezoidal membership functions. At the first level, they are formed automatically depending on the characteristics of the complex signal. The output function at the first level is given by a singleton function, and defuzzification is carried out using a simplified center of gravity model.

Results. The proposed algorithm was implemented in the developed device based on a programmable logic integrated circuit (FPGA). In addition to filtering, the developed device implements all signal processing functions, such as: receiving input data, decoding, checking the correctness of decoded data, storing them, transmitting ADS-B messages for further processing. A distinctive feature of the device is its small size and low power consumption, which allows use it in small spacecraft and unmanned aerial vehicles.

Conclusion. A method of filtering complex signals based on a fuzzy logic model is considered, which can be used to filter complex signals, such as ADS-B messages in small spacecraft modules. The proposed implementation of the filtering method makes it possible to increase the sensitivity of the AZN-B signal receiver by 20% and correctly decode the received signal. The method was implemented by an FPGA-based device, which made it possible to reduce the size and power consumption compared to analogues.

Purpose of research. The main idea of the article is to develop a digital device created on domestic components and designed to record measurement information with the function of recording on a memory card and transferring it to a personal computer using a USB-interface. The article also considers the tasks to be solved.

Methods. Having analyzed possible alternative variants of development of the registering computer system, the authors offer a variant of its realization on the microcontroller, in the software of which it is necessary to provide the following functions: realization of information exchange via RS-485 interface; realization of exchange via USB 2.0 interface for transfer of the accumulated registered information to the computer; realization of recording, reading and erasing of the registered information on the flash-drive; realization of the counter of its own time with uninterrupted work at the time of the registration of the information on the microcontroller.

Results. This paper develops a digital device designed for digital registration with the function of recording measurement information on an SDHC memory card. The operation of the device consists in providing registration of information with saving it in the form of files on a memory card of SDHC format. Access to the registered information is made from a computer via USB 2.0 interface in the memory device mode by means of a software driver realized in the microcontroller 1986BE92T of the Milandr company. Initialization of the device is carried out with the help of a computer, through the driver implementing hardware bridge USB-UART on the standard USB 2.0.

Conclusion. The obtained results satisfy the set goal and objectives. A textual description of the microcontroller firmware in C language is developed. In addition, the paper develops application software designed to obtain measurement results and send control commands to the microcontroller. The field of application of the proposed device is specialized computing systems designed for digital recording of information.