The article examines the issue of calculating the depth of compression stresses when using a spherical indenter in order to increase the fatigue strength of steel parts. When the spherical indenter is pressed, elastic deformation of the surface first occurs, and then plastic one. The residual plastic deformation is expressed in the size of the print. The physicomechanical properties of the processed material are not taken into account, the process of pressing a spherical indenter into a steel sample in the ANSYS program is modeled by the final element analysis (FEA).A bilinear deformation diagram was fed, which is set in the program by the modulus of elasticity, yield strength and Poisson's ratio. At the next stage, a finite element grid was generated by using the Hex Dominant Method, which divided the model into elements in the form of hexahedra of various sizes. In the contact area, the size of the finite elements was 0.2 mm. The results of calculations of analytical and numerical methods for spherical indenter diameters of 4, 6, 8, 10 mm and various degrees of plastic deformation to determine the depth of compression stresses are presented, compared with known data, the error is calculated. A dependence is derived for a preliminary assessment of the occurrence of residual stresses depending on the diameter of the well after the indentation of the spherical indenter.

Keywords: spherical indenter, bilinear deformation diagram, plastic deformation, indentation depth, compression stress

The conclusion of the relations for the study of the propagation or diffraction of electromagnetic waves in the semiconductor layers of composite materials, which are also recommended to be used in the creation of onboard antennas and microwave devices with less weight. Both exact and simplified mathematical expressions for the rapid quantitative estimation of the complex wave number are obtained. Using the example of carbon fiber plastics with high conductivity, it is shown that their use makes it possible to create waveguide paths and antenna reflectors up to a millimeter wavelength range.

Keywords: carbon fiber, electrodynamics, composite, propagation, absorption, antenna

This article is devoted to the possibility of using random access memory as a pluggable disk array in order to speed up calculations within a heterogeneous computing system. The problems of using a RAID array of hard drives as the main disk space for storing data generated by applications for a heterogeneous system of tasks are considered. The principles of using random access memory as a disk space are presented, as well as the features of connecting to the thus obtained data storage via a network.

Keywords: parallel computing, file system, random access memory, mounting, heterogeneity, computer complex

The subject of research is the development of a service for generating various forms of a given word based on the analysis of words found in the dictionary. The available approaches to solving such a problem were studied and the most relevant one was chosen. The service searches inside the dictionary file with text content in order to automate the process of selecting the necessary words among the entire set. The search for the stem of the word is performed, taking into account the morphology. Performing a morphological analysis of a word, a common basis for all its grammatical forms is found, cutting off suffixes and endings. As a result, the service algorithm allows you to search for all forms of a word by a given keyword, taking into account word forms. At the same time, it also analyzes which part of speech the word belongs to, this allows you to set different methods for determining word forms. For each type of word: verb, noun, adjective, adverb, its own algorithm is used to highlight word forms. The peculiarity of the service is that it allows you not only to search for word forms in the dictionary, but also allows you to generate sets of word forms based on the type of a given word. The service operates on the Linux platform under the control of the Apache web server. Free software tools were used for development. The development was carried out in JavaScript, HTML and CSS, the server-side programming language PHP7 was also used.

Keywords: search engine, document analysis, linguistics, word forms, morphology, word generation, web service

The calculation for progressive collapse with variation and comparison of different scenarios was carried out for the frame of a unique high-rise building of a multifunctional complex. At the first stage, the calculation was performed in a quasi-static formulation, the maximum deflections for two destruction scenarios were determined. The requirements for the state of limited operability in conditions of progressive collapse are completed. At the second stage, the calculation was made in a dynamic formulation. A modal analysis of the frame was previously performed in order to determine the forms of vibrations that will correspond to the expected deformations of the structure in the event of the occurrence and development of the process of progressive collapse. It is established that the maximum deflection of the plate when calculated in a dynamic formulation is 27.6% greater than in a quasi-static one. The residual deflection after the attenuation of the oscillatory process is 4.6% less than in the static calculation. Therefore, the object of study is safe from the point of view of the possibility of an emergency situation, accompanied by partial destruction of load-bearing structures.

Keywords: parametric architecture, evolution of shaping, aerodynamics, finite element method, analytical surfaces

In the article the authors consider the influence of development institutions on the formation of the knowledge economy, it is proposed to evaluate their quality in the form of an index of institutional development. A method of evaluation based on objective indicators is proposed. A model for ranking regions is presented, including the calculation of indicators, on the basis of which a comprehensive integral assessment of the index of regional institutional development is carried out.

Keywords: knowledge economy, regional economy, innovation economy, innovation activity, socio-economic development, institutional infrastructure

With the right approach, the heat generated by chillers in an indoor ice rink can be used to melt ice, a dehydration system, or to heat a concrete pad under a layer of ice. In this way, energy can be saved. For the purpose of accumulation and subsequent distribution of thermal energy in the building, a reservoir that accumulates heat can be used. Heat is removed from the chiller condenser by a water cooling circuit, which is connected to the coil of an indirect heating boiler (heat accumulator). The coil heats the water that circulates in the heating circuit. Since the load on the ice can change during the day, heat extraction will occur in different amounts. For efficient transfer of thermal energy from one heat exchanger to another, it is necessary to control the speed of rotation of the pump impeller so that the controlled function is maximum. If the speed is insufficient, then the heat exchange flow will receive less heat. On the contrary, if the drive drives antifreeze too quickly, then the coolant will not have time to heat up. A mathematical model of the system was compiled from a plant condenser and a boiler with heated water, a dependence on the speed of the coolant (antifreeze) and the temperature difference at the inlet and outlet of the accumulator was revealed.

Keywords: heat accumulator, temperature control, shell-and-tube heat exchanger, optimal regulator, freon

The article presents an analysis of the problems of diagnosis and restoration of the human respiratory system after diseases, including COVID-19. The review of analogues of small-sized spirometers is carried out. On the basis of which an individual small-sized device has been developed for effective training of the respiratory system. The functional scheme of the pneumatic trainer is described and the main simulator-game scenarios for achieving a therapeutic effect are analyzed.

Keywords: respiratory system, COVID-19, pneumatic trainer, portable device, pressure sensor, MEMS technology

This paper presents the principle of operation of the algorithm for translating a graphical representation of neural network models into a program code within the framework of a neural network repository. Based on the obtained data structure, it is possible to carry out sequential generation of program code in a general-purpose programming language.

Keywords: neural network model, neural network, repository, graph model, programming, translation, spatial data, algorithm, topology, architecture

The article discusses the features of numerical modeling of the limits of fire resistance of structures under the influence of standard and hydrocarbon temperature regimes. After carrying out the assessment using the proportionality coefficient, it is necessary to carry out a verification calculation of the structure tested under the standard temperature regime of the fire, and if the results obtained coincide, the calculation of the structure under the hydrocarbon regime.

Keywords: fire resistance of concrete building structures, standard fire temperature regime, hydrocarbon fire regime, fire resistance

The essence of the proposed is the arrangement of the frame from the channel around the coating beam. At the same time, the frame elements can be subjected to controlled effects, in the form of overvoltage in them, which is realized by specially installed traction brackets. The study of the proposed structural and technological solution, implemented by a channel frame, was carried out using digital technologies based on numerical modeling. In the proposed calculation model, the beam reinforcement area was changed due to the introduction of a reinforcement frame. In the Etabs software package, using the finite element method, transverse forces and moments were calculated in the newly formed system - a beam plus a channel frame. The paper considers the issue of the influence of the frame on the transverse force in the beam. Using the technology of processing large arrays of numbers, a mathematical model of the process was obtained when the beam was reinforced with a channel frame. A consistent analysis of the mathematical model was carried out, which allowed to state the correctness of the decision and assign the design dimensions of the device and its technological parameters.

Keywords: reinforced concrete beam, reinforcement, channel, reinforcement, shear force, load, numerical method, mathematical modeling, numerical modeling, mathematical model, Etabs software package

This article discusses the urban planning concept of camping sites as objects of roadside service. The functional structure of the camping is considered. The analysis of the transport infrastructure and tourist flow of the Arkhyz district is carried out. The scientific experience in the organization of the camping system is considered. Based on the analysis done, a model of the formation of the functional structure of the camping system has been compiled.

Keywords: camping, transport infrastructure, roadside service facilities, auto tourism, tourism, camping industry, camping system

As part of the optimization of the design solution, studies of a cylindrical rod roof with increased rigidity of the support ribs and taking into account the reinforcement of the system with puffs were carried out. The required distance between the tension elements along the length of the structure is determined and the dimensions and shape of the section of the lower ribs are proposed. An optimality criterion with control parameters has been developed and three standard sizes of rods for the greatest efforts have been taken into account. Internal force factors and node movements with and without reinforcement are obtained. A positive redistribution of efforts on the surface and a decrease in the deformability of the roof were revealed. The dependence of the main geometric parameters on the mass is established.

Keywords: cylindrical rod roof, stiffness of support ribs, reinforcement by tightenings, optimization, forces, displacements, mass

The article provides a brief analysis of the processes that occur when starting an electric motor. Mathematical relations modeling the process of starting a direct current motor are presented. Graphical dependences allowing to determine parameters of a thermistor providing an optimum start-up of a direct current machine have been obtained.

Keywords: starting current, thermistor, starting rheostat, thermal characteristic, DC motor, boundary conditions, torque resistance, idealized rheostat, heat loss, economical starting

The paper proposes and calculates a scheme of a two-stage gas turbine plant using carbon dioxide as a working fluid in the second stage and using heating of the CO2 circuit, as well as heating water sent for heating. As a result, the following were calculated: for the first stage turbine: parameters of fuel combustion products; air compressor parameters; fuel compressor parameters; combustion chamber parameters for a real Brayton cycle; Efficiency of the first stage turbine; for the second stage of the gas turbine: a schematic diagram was drawn up using liquid CO2 as a working fluid; calculation of CO2 parameters at key points of the Brayton cycle; the efficiency of the turbine of the second stage is calculated.

Keywords: energy efficiency, gas turbine plant, carbon dioxide, pressure, pressure ratio, combustion chamber, recuperator