Table of contents

IV International Scientific and Technical Conference "Mechanical Science and Technology Update" (MSTU-2020) were held from 17-19 March, 2020 in Omsk State Technical University, Omsk, Russia.

The conference materials cover the generalized issues of achievements in applied mechanics, engineering and materials science, quality management, mathematical modeling of processes, numerical solution of differential equations and development of micro-mechanical systems.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

A functional diagram of a robotic complex mock-up for rejecting ball-shaped objects transported on a roller conveyor is presented. The software of the complex is designed to detect an object on the conveyor and determine its coordinates. To detect objects of control, their images obtained in the visible range of the optical spectrum and Viola–Jones object detection algorithms are employed. The developed software is based on a trained cascade classifier, the optimal settings of which are determined. To detect surface defects of objects, their spectrograms obtained in the range of 400... 1000 nm are used. The presented results can be applied to the process automation of sorting fruits and vegetables and other ball-shaped objects.

The development of an oscillistor based force sensor with a frequency output is introduced. Sensor can operate in a wide temperature range from room to cryogenic. Experimental studies were carried out at temperatures of 77 and 295 K. Force sensor sensitivity is 0.9 kHz/N in the force range (0–10)N at temperature 295K. A decrease temperature to 77K leads to increase sensitivity to 15 kHz/N. The design of the oscillistor based force sensor is presented.

The issue of distribution of large amounts of information on server stations is researched. The analysis of existing methods for distributing data of heavily loaded web applications is carried out. A system for computing load distribution using a balancing server is proposed. A description of the software necessary for the functioning of the system and server management interface is provided.

The paper discusses the optimization of a pulsed automatic control system (ACS) with constant parameters, which is used to control non-stationary objects. We obtained the dependences of the integral quality criterion on perturbations acting on the control object. The sensitivity of the ACS was studied by simulation using MATLAB / Simulink. The system was optimized based on the criterion constructed taking into account sensitivity to parameter variations. It is shown that the synthesis of the ACS insensitive to changes in characteristics is advisable only if the deviations of the parameters are small. In this case, the quality of automatic control will improve.

The issues of creating an automatic control system (ACS) as part of the software and hardware complex (SHC) designed to control the technological equipment of the turbine compartment of a nuclear power plant are considered. Multicriteria optimization was carried out using ACS simulation and an optimization method based on a genetic algorithm implemented by the MATLAB / Simulink / Global Optimization Toolbox. The approximation of SHC relay-pulse controllers, which are used in control loops, by linear regulators, is carried out. Based on this, an analysis of the system stability was performed. Resistance margins are determined taking into account the influence of signal discretization in control loops. The studies showed that the optimized ACS has sufficient stability margins and provides the accuracy of maintaining the object parameters in the normal operation of the power unit.

A methodology for measuring and processing the primary measurement information when estimating the deviation from flatness of significant large-scaled objects is considered. The laser measurement system used and the algorithms used to process the measurement information are described.

The parameters defined the items quality FDM 3D-printed on the flexible modified polymer substrates were determined as exemplified by monitoring the 3D-process of the periodical elements forming on the oxyfluorinated PELD and PET films aimed to the production of the prototype model of a lab-on-a-chip device. Due to SEM, EDS and FTIR techniques application the correlation between the modification mode parameters and the elements operating stability was connected. The general approach to the 3D-printing process quality estimation on the modified polymer substrates is shown.

Fiber-optic sensors are becoming wide spreading in many fields due to a lot of advantages such as high spatial resolution, small size, immunity to the electromagnetic disturbances and possibility of multiplexing. Many benefits are fundamentally unattainable for electrical sensors by the physical operation principles. The processing of signals received from the optical fiber temperature sensor is considered. Raman sensor provides high spatial resolution. The main problem of signal processing for the temperature calculating is a large noise arising from the low level of current received from opto-converter. A method for estimating the additive noise level is presented based on calculation of the standard deviation. Comments concern the multiplicative noise during the rise and fall of the signal are given. Possibilities of guaranteed identification of DTS signals based on experimental measurement of statistical characteristics and representation it as so-called potential characteristic is evaluated. The signal-to-noise ratio may be increased by averaging the potential characteristics.

Paper presents algorithm calculation of automatic mixing (nonmixing) conveyor to obtain mixtures of single, piece tubular elements having similar typical overall dimensions, but differing in internal properties at effective end use. The relevance and novelty of development are shown on the example of receiving the general party of composite tubular product, at the determined forming of its uniformity, with the set qualitative and quantitative characteristics from the heterogeneous tubular components differing in functional parameters

Paper presents pilot studies of the automatic conveyor mixer (nonmixer) and batchers for receiving mix of the single, piece tubular elements having similar standard overall dimensions, but differing in internal properties at effective end use. The relevance and novelty of development are shown on the example of receiving the general party of composite tubular product from small similar parties, at the determined forming of its uniformity, with the set qualitative and quantitative characteristics from heterogeneous tubular components.

Results of pilot study and their statistical processing on the basis of multiple-factor experiment are provided. Operation of the stand of the lock feeder applied to dispensing of bulks from metal powders by way of time separation from the flow of micro doses of components given by the feeder was investigated. These feeders are used as the automation equipment in conveyor, rotor and birotary non-mixing installations. Regression models for determination of the actual productivity of lock feeder are received. It is established that dependences of productivity of lock feeders on the circumferential speed of rotation of the dosing drum and its operating volume are nonlinear. At the constant volume of grooves, the same productivity can be received at different values, the circumferential speed of drum that is at implementation of the different kinematic modes. At design and the choice of processing equipment it is necessary to use the received dependences that will allow on the set actual capacity of the feeder to choose geometry and kinematic parameters of process of dispensing.

The author suggests using a method based on cell models to develop dynamic mathematical models intended for the smart control of oil production facilities. The method is applicable both to the facilities with lumped parameters and for those with distributed parameters (being more suitable for the latter as they are more complex in terms of computations). The paper provides the examples of mathematical description of the processes performed using the cellular model for some vessels most widely used in oil production, and the examples of simulation of controlled facilities by MATLAB Simulink, as well as the simulation results in the form of statistic and dynamic characteristics of the facilities by various channels, which are consistent with the experimental data. The general simulation methodology is formulated. The models obtained can be implemented in industrial automation for oil production industry.

This paper presents a novel architecture of wideband signal analyzer based on time-interleaved ADCs. Architecture of signal analyzer include improved method of digital calibration of ADC channels operating in the time-interleaved mode of input signals. This method is based on the least squares method. The advantage of the proposed method is high speed and high accuracy of ADC channels tuning in comparison with the majority of existing methods, which are based on the least squares method. The results of simulation modeling of the proposed method, including spectral analysis of the output signal before and after calibration, are presented. The comparison of the proposed method with existing methods is performed.

The relevance of problems of diagnostics and monitoring of the technical condition of electromechanical equipment is shown. An overview and analysis of specialized methods and technical tools designed to solve these problems are given. The main problems that arise in the practical application of modern methods and diagnostic tools are identified. The main advantages of using methods of diagnostics by electrical power consumption parameters are considered and the results of an analytical review of these methods are presented. A variant of the practical implementation of a stationary diagnostic complex for electromechanical units and the results of the development of functional schemes of the main components are proposed.

The paper considers the development of an algorithm for controlling the orbital motion of a small spacecraft using a control system that has flywheel engines and an electrothermal micromotor for unloading flywheels as executive bodies. It is assumed that a small spacecraft periodically falls into the shadow of the Earth. The temperature deformations of solar panels that affect the dynamics of evolution around the center of mass are taken into account. The restrictions on the internal environment micro-accelerations of a small spacecraft are taken into account when choosing the main parameters of the executive bodies. These restrictions are imposed when gravitationally sensitive technological processes are carried on board it. The aim is to reduce the level of micro-accelerations in the zone of technological equipment as possible while developing control algorithms.

Statistical computer modeling is implemented to analyze an autonomous system for navigation data integrity monitoring of satellite radio navigation systems using the measurement residual summation method in a sliding window. The analysis is made for integrated optimal information processing algorithms obtained by the methods of the optimal estimation Markov theory. Algorithms are generated for the vertical channel of the navigation complex, which includes an inertial navigation system, signal reception equipment from satellite radio navigation systems, and a barometric altimeter. The possibility of detecting unreliable data in using different measurement residuals, as well as depending on the size of the sliding window, is investigated in the modeling process.

The subject of the study is a system for collecting and processing biophysical signals for controlling anthropomorphic prostheses. As a result of the work, structural and electrical circuits for measuring biophysical signals, processing and filtering schemes were proposed, and the necessary filters were calculated. Designed filters allow you to get rid of noise caused by artifacts of movements and your own signal instability, and can be used to design a system for collecting and processing electromyography signals. In conjunction with a digital filtering system and further processing, it is possible to adequately determine the presence of muscle contractions. The resulting system is small-sized and in combination with the software part of signal processing will allow you to determine key signal patterns and control anthropomorphic prostheses.

Establishing patterns of the relationship of informative diagnostic parameters signals's and test modes and operation of rolling bearings is an urgent task of technical diagnostics. The determining factor in the use of certain methods for assessing the condition and bearings faults, as well as the use of certain informative diagnostic parameters, is their sensitivity to changes in the condition of the bearing or to the size and degree of the defect development. The paper presents the results of the dependence study of the rolling bearings vibration parameters on the test and operation conditions: the rotation frequency of the inner ring, axial and radial loads. Numerical values of the listed factors are obtained that are optimal for testing bearings at the input control according to the sensitivity criterion. The study was conducted in accordance with the provisions of the experiment planning theory. It has been established that the magnitude of the vibration parameters and the level of components at the frequencies of bearing defects depend on the speed of rotation in direct proportion and increase with the deterioration of the technical condition of the bearings. It was experimentally confirmed that axial and radial loads significantly affect the values of the controlled vibration parameters only when defects appear in the tested bearings.

The paper considers approaches to assessing the technical condition of the inking unit drive of printing machinery in the work environment. As the main diagnostic feature, it is proposed to use the noise spectrum, created when working with inking systems. Reasons for noise of inking systems are considered. To create a mathematical model of sound radiation by quill cylinders of inking system, it is shown that behaviour is described by oscillation equation of tubular girder. Theoretical research has shown, there is a possibility in principle to use the noise spectrum emitted by the inking system to diagnose the technical condition of its drive. To improve the accuracy of diagnosis, it is proposed to use neural network technology of image identification.

The article presents a model of mechanical contact of a spherical tip and a product with small forces according to elastic deformations (further – deformations) taking into account the appearance of material deformations in the gap between them along the perimeter of the contact zone in the form of so-called piles-up. Dependences are obtained that link the gap with the deformation and the piles-up size. A graph is constructed for these parameters, the general form of which is close to the function of a single jump ∼1(l-R_pile), where R_pile is the radius of the pile-up.

The developed design and operating principle of the scanning hybrid fiber-optical measuring head (FOMH) based on the use of a small-sized spatial light modulator in the form of a fiber-optic piezoscanner with the formation of scanning movements of the laser beam and the measurement of gaps between the tip and the product are described. The possibilities of providing high-precision measurements of laser beam deflection angles during scanning movements by using acousto-optic heterodyne interference measurement systems are considered.

Calculation of uncertainty and identification of influencing factors is one of the current problems of measuring instruments (MI) operation, because testing programs of MI including only typical influence and don't take into account specific measuring instruments. Calibration of measuring instruments during their operation and calculation of uncertainty of measurement results will allow to establish in the long term the actual values of measurement results traced to the national primary standard. One of the tasks in assessing the uncertainty of measurements is to assess the impact of calibration conditions, which is evaluated based on parallel measurements at each calibration point. The aim of the study is to develop a method for determining the number of parallel measurements when calibrating thermal measuring instruments on the basis of statistical information based on the results of verification of measuring instruments. In that research, was determined and experimentally tested method for determining the number of parallel measurements during calibration of thermal measuring instruments. The method was tested on the calculator of a quantity of heat VKT-7. Was identify strengths and weaknesses parts of the technique, as well as its field of application, have been revealed.

The comparative analysis of the most popular techniques features (SEM, EDS, XPS, FTIR) applied for the quality monitoring of the polymer materials modification process is carried out as exemplified by the both 3D-microfluidics and flexible printed electronics substrates manufacturing. The typical errors at the both microstructure and composition instrumental analysis of the modified heterogeneous near-surface layer of the polymer material are listed. The reasonability of the cyclic chemical as well as morphological statistically significant technique of the date acquisition accompanied by the source generation signal gradient variation is shown. The developed general algorithm of the polymer modification process instrumental monitoring is presented.

The paper parameters were selected for a computer model using open source software to predict their interaction with the dampening solution in an offset printing machine and in an ultrasonic measuring device. The indices characterizing the penetration of alcohol-free and alcohol dampening solutions with 5% and 10% content of isopropyl alcohol into the structure of offset coated papers on PDA c02 ultrasonic measuring device were obtained and analyzed. The surface profiles of coated offset papers are obtained on a Micro Measure 3D Station three-dimensional non-contact profilometer for constructing the surface geometry of papers in a graphical interface. A t_{startswelling} value was found characterizing the time of the beginning of fiber swelling in the paper structure, which will allow setting the time for calculating the numerical model. The obtained t95 and USI 70 indices are recommended for an indirect assessment of the identity of a computer model to the actual conditions for the onset of interaction and penetration of dampening solutions into the paper pores.

The paper considers the methodology of the proposed integrated approach to mathematical modeling of the actual feed rate of various designs of mechanical disk pocket hopper-feeding devices. The approach allows us to estimate the actual feed rate of the device for various types of axisymmetric parts of the shape of rotation bodies with sufficient accuracy for practice at the design stage. The mathematical model of feed rate takes into account the probability of gripping axisymmetric parts of the shape of rotation bodies with different geometric parameters, as well as the design and kinematic parameters of feeding devices.

Results of pilot studies of comparison of process of backup on the Windows and Linux operating systems are presented. Experimental and analytical means revealed the key parameters influencing backup process speed. As showed a research, the most significant parameters are the form of the interface of the software and type of the operating system. Also the limit at which the speed of copying of data remains rather balanced was set. The research showed that "direction" of copying of data is also very important. The software capable to make backup in the environment of operating systems Windows and Linux was developed.

The issue of improving the efficiency of the information and measurement system of automated air traffic control systems on the example of the distance measuring channel algorithm synthesis for following up the aircraft is considered. The choice of state and observation models is justified, computer simulation is performed, and the results of the studied algorithm are obtained.

It is represented a possible way to standardize and to automate the quantitative description and the analysis of the formed by the scanning electron microscope polymer based films surfaces' images. Also there are the calculating algorithms for the topographic model forming and the degrees of planar and contour digital heterogeneities calculating and the analysis process model with the computer application interface and the corresponded results of the sulfonated and fluorinated low-density polyethylene films SEM-images' characterization. Due to the universality of the proposed techniques for quantitative image description and simulating they can be used in quality control systems under the design and manufacture of the surface-modified polymer films.

The article reveals the main provisions of technical diagnostics of gear hobbing machine system with CNC on the diagnostic parameters of the profile of the sides of the teeth. The scheme of embedding diagnostic processes in the cycle of improving the quality of manufacture of gears. The developed scheme is universal and applicable to any gear processing operations. It consists of several successive steps – the evaluation of indicators relative to the limit values, the identification of the technological structure of the profile errors and the identification and analysis of diagnostic deviations of the profile of the lateral surface of the teeth, indicating. Each step of the improvement cycle is necessary to determine the negative factors of the process leading to a deterioration in the quality of manufacture of gears. Application of technical diagnostics profile diagnostic indicators allows to detect deviations of the technical condition of machine components, adjustment or tuning machinery. Diagnostic indicators are identified for the most significant technological components of non-conforming errors of the profile of the sides of the teeth of the gear wheel. The advantage of this quality improvement scheme is that it is more efficient than traditional methods of statistical quality management.

The quality of materials is evaluated by non-destructive testing of their thermo-physical properties in the manufacturing process. A relevant aspect in determining the quality of products at the manufacturers is the development and application of an intelligent information and measurement system for operational control in the quality properties of heat insulating materials. The objective of the study is to improve the efficiency and accuracy of determining the thermo-physical properties of the test materials by solving the problem of reconfiguring the system structure in accordance with the specified algorithm of operation, making decisions on the choice of a method for non-destructive testing of thermo-physical properties of materials, and an approach to building the structure of an intelligent measuring system. The solution for the problem of system architecture configuration with artificial intelligence methods according to information and measurement situations in the operation of the system is proposed. Intelligent decision-making procedures are presented when choosing a method for controlling the thermo-physical properties of materials as a result of identifying the measuring situation. An approach to the construction of the intellectual information-measuring system structure for operational control of material quality properties based on the selection of system structure and control method for thermo-physical properties of materials adaptive to the class of test materials by thermal conductivity to improve the efficiency and accuracy of thermal measurements is created. The results of experiments to determine the thermo-physical properties of heat insulating materials using an intelligent information and measurement system are presented. The analysis of the obtained results confirms the control accuracy increase in the thermal properties of materials.

The rapid development, complexity of modern information systems and the growth of qualitative and quantitative characteristics of network anomalies and failures makes the task of network reliability more relevant. So, the aim of the article is to research modern problems of information systems and develop methods for its solution. For resolving of the considered problems in order to achieve the required level of network characteristics, the article contains developed the conditions for the optimal choice of network equipment, the methods for determining threshold values for detecting deviations from the normal operation of the network, the schemes of the algorithm for monitoring faults and problems.

The paper describes a method of electronic control of laser phase for laser interferometry. The method utilizes acousto-optic interaction and ultrasonic wave diffraction. The article presents an opto-electronical scheme for phase shift control with high resolution in reference and object beam without using high voltage.

In this study we report a change in the geometry of space during its quasi-rotation relative to an ellipse. Symmetric interrelation, generated by the quasi-rotation around the elliptic axis is considered. The possibility of an arbitrary point quasi-rotation in the R³ space around the elliptic axis is confirmed and discussed. Further, we analyze the properties of quasi-rotation surfaces. In the considered examples, a circle within the quasi-rotation axis's plane is adopted as a generatrix. The algorithm used to build 3D graphs is based on a mathematical description of the method of rotation of a point around a second-order axis curve. A symmetry interrelation with respect to the elliptic axis is considered. The generated images are analyzed to determine the structure of their self-intersection and self-touching. Flat intersections of the surfaces under study are generated. Geometric methods were used to determine the order of the surfaces. It was established that in the considered example that quasi-rotation of the circle that belongs to the quasi-rotational elliptic axis' plane, a surface of the twentieth order is formed.

The background of description of the method for geometric objects rotation around the curved axes in the form of curves of the second order is being considered. The above-described method got the name of "quasi-rotation". The algorithm of geometric construction of the two-two-digit interrelation on the basis of the circular axis of symmetry is provided. The described interrelation is analogous to the mirror symmetry regarding a straight linear axis. The method is suitable for construction of some well-known algebraic curves. The analogies between rotation and quasi-rotation are determined and described. The formula of the same plane preimage-to-image interrelation, generated by the quasi-rotation around the curved axis of the second-order curve is provided. The presented formula allows to derive the equations that effectively describe images of the given sets. The method for geometric construction of the images of geometrical objects lying within the plane of the second-order curve at their quasi-rotation for a given angle regarding the curve is described. The obtained results describe geometrical basics for the quasi-rotation. They serve as the basis for shape-forming of algebraic surfaces of high orders, and can be utilized as the theoretical basis for the computer-aided automated geometric projection.

This paper is devoted to the mathematical and computer simulation of multi-parameter technological systems. The method and algorithm can easily be used in spline-frame simulation of the systems. Simulation is based on experimental data and achieved by the variation of one-dimensional spline approximations. A set of variable one-dimensional cubic spline-frames generate the model of hyper-surface, which is a model of the process. Each of the spline-frames is the image of a section of input parameters area. Software realization is based on the single algorithm that is used repeatedly. The problem of building some model of hyper-surface is based on empirical irregular 0-dimensional frame. We consider the problem as an inverse problem of modeling. The method has been used in investigation some technological conditions of thread seams for sewing industry. We investigated the durability and harshness of the seam. Geometric models and parameter valuations were generated by special software. The equations and diagrams described our experiments with sufficient exactness and there were used for researching the process. The model together with software HYPER-DESCENT may be applied for simulation multi-parametrical systems or technological processes of light industry.

This article describes algorithms simulating the trajectory of the intended movement from the pursuer to the target at any given time. In the previously considered models of adaptive behavior, the pursuer and the target analyzed the coordinates of the opponent in the game and made an automatic decision where to move. In the models described in this article the behavior of the pursuer is determined by the location of the intersection point of the radius circle equal to the discrete step of the target and the assumed simulated trajectory at a given time.

This article describes a geometric model where a group of four objects pursues a single goal. The movement occurs on a plane, but if necessary, this model can be applied to an explicitly specified surface. The movement speed of all participants, both pursuers and targets, is constantly modulo. The goals and strategies of each of the pursuers are different. The goal and strategy of the target is determined by the behavior of one of the pursuers

The paper proposes an approach to modeling geometric multifactorial processes and phenomena using mixed geometrical interpolants, for example of the steel fiber concrete strength characteristics' simulation A key role is played by the formation of the geometric model, as developed in detail in the article. Analytical description of the geometric model obtained by means of algebraic curves (that pass through the predetermined point in advance) is realized by means of the BN-calculus mathematical formalism.

The paper presents a general algorithm of determination of catacaustics given a curvilinear source and a reflector. The algorithm is based on the method of cyclographic mapping as well as the optical property of a cyclographic projection of a spatial curve. The algorithm is consistent and universal; it is suitable for every problem where the light source is given in the form of a central, parallel or diffuse bundle of rays. Through the presented algorithm the analytic solution to the problem of determination of catacaustics is acquired. The results of the study can be utilized in applied geometric optics in design of optical systems consisting of the triad of elements: a light source, a reflector and a receiver.

The paper considers family of working contour-parallel lines formation used in the design of the toolpath that processes pocket surfaces. Contour-parallel working lines are the ones from which the lines-noises, i.e. non-working sections, are removed. Non-working sections include self-intersection loops and intersections of oncoming fronts in the case of multiply-connected domains. The spatial geometric model of forming contour-parallel lines is based on the cyclographic mapping. As a tool for detecting non-working sections for the case of oncoming fronts, the method of a testing ray is proposed. In case of self-intersections of contour-parallel lines, non-working sections are cut off by the parameter of these lines at the points of self-intersection. At the output of the proposed shaping algorithm of the working contour-parallel lines family, the parametric equations of these lines are formed. The algorithm successfully works for multiply-connected domains with polygonal and curved contours of the boundaries of the domain and islands in it. A comparative evaluation of the proposed method of forming a contour-parallel lines family with trimming non-working sections and the known methods that use the distance function is performed.

The work is devoted to solving one of the problems of robot motion virtual simulation using computer graphics. The paper offers a method for studying the shape and position of the work envelop of manipulator mechanisms in the presence of restricted work envelopes in the workspace. The method for determining the work envelope is based on the construction of allowed configuration of robot mechanisms. A parameter describing the structure and maneuverability index in different parts of the work envelope is proposed. The construction of cross sections of service areas for different positions of restricted work envelopes allows determining the areas where the output link centers of various mechanisms can not be located. The conducted research makes it possible to place the trajectories of the output link in solving motion problems, which reduce the probability of deadlocks in the automated motion synthesis along the velocity vector.

The article describes an example of the practical application of graphic computer simulation methods to determine the setup parameters of gear-broaching machines. The adjustment parameters found using computer simulation methods provide a favorable distribution of lateral clearances to achieve the design positions of the total contact spots along the sides of the valleys of the gears. The determination of the adjustment parameters consists in imitating the process of gearing which results in 3D models of bevel wheels. The troughs of the interacting 3D wheel models are dissected along the inner, middle and outer cones. Graphic run-ins were performed for the side profiles of the wheel cavities along the length of the tooth. The graphs of changes in the lateral clearances of the tooth tooth profiles are constructed and the best position of the extrema in the middle part of the side surface of the tooth teeth is selected. Thanks to the application of graphical modeling methods, it becomes possible to exclude from the total adjustment error the errors of parts and moving machine parts that are individual for each gear-broaching machine.

In recent years, the construction of churches and temples has been rapidly developed, so the need for design and support for such constructions arose. A new department called "Temple architecture" even appeared at MArchI (Moscow Architectural Institute). The article considers a method for geometric construction of the surface of such objects as the dome of temples and churches from the parts of Dupin cyclides. As a result, two variants of domes made from the compartments of the Dupin cyclide were proposed. Based on the theoretical research, it becomes clear that there can be more design options, and if we use a special case of cyclides for construction - compartments of rotating cones - then many times more.

One of the important processes in operation of a printing machine is the transfer of a sheet of printed material from one cylinder to another. The transfer of the sheet is carried out using special grippers attached to the printing cylinder, and quality of printing depends on their accuracy. At the stage of printing process preparation, an important step in setting up the equipment is the correct installation of the grippers. The paper presents the results of developing a geometric model of the sheet transfer process from grippers to grippers. This process is visualized using a computer simulation. The presented model makes it possible to define the trajectory of the paper movement in the transfer zone, and track the untimely opening or closing of grippers. This may lead to printing process abnormality.

The classification of the optical fiber types and influencing factors by using the Brillouin reflectograms are considered. The programs for automated data processing of Brillouin reflectograms are presented. The types of the optical fibers are determined by the characteristics of the frequency profile of the Mandelstam – Brillouin scattering spectrum. Based on the analysis of Brillouin multi-reflectograms, we can detect the factors that effect on the characteristics of the back-reflected Mandelstam – Brillouin scattering signal in the tested segments of the optical fibers.

Topic relevance is due to necessity of the correct mathematical expressions during the calculation of constants of equivalent circuit of power supply system, including the overhead transmission lines. Research purpose is the allowances thanks to which formula for capacity admittance calculation and of ground fault current in electrical grids with insulated neutral determination were deduced and made common use. As exemplified by numerical computation accepted allowances can lead to significant error (more than 15%), for example, during the determination of single phase-to-ground fault current in electrical grids with insulated neutral.

The modern variety of methods for diagnosing the condition of a heat conduit requires a systematic approach and structuring. The methods classification based on the IDEF0 methodology for analyzing the technical conditions of the pipeline and the requirements for their implementation are proposed. Modern methods and technologies for searching coolant leaks are considered., the use of which is possible outside of hydraulic tests and changes in transportation technology. The proposed options for expanding existing software and hardware are considered and trends and prospects for their future development are identified.

Currently, the majority of electric centrifugal pump installations are equipped with submersible induction motors. The simulation models' development and the study of operating modes based on them should be accompanied by verification of the data obtained with experimental results. It is due to the design features of this electric motors' type. Therefore, the aim of the article is to study the performance of submersible induction motor with a power of 70 kW. The performance is obtained on simulation model and their verification with experimental results. The simulation model of SEM-YA 70-117 M5B5 submersible induction electric motor is developed in the MATLAB/Simulink software environment during the research. The performance characteristics are also built. It is established that the relative error of the values obtained during simulation to the experimental data does not exceed 10 %.

In this paper, we consider the effect of the polarization effect of electro-elastic and magneto-elastic parts of an electro-magneto-elastic heterostructure on its dynamic characteristics. As the studied heterostructure, a packet of layers lying on half-space was selected. It is assumed that the layers are mechanically rigidly adhered to each other. The electrical and magnetic conditions at the layer boundary can be either completely open or completely shorted. Given the variable boundary conditions, the Green's function of the heterostructure was constructed and the phase velocities were obtained. The electromechanical coupling coefficient in the heterostructure is obtained for various geometric proportions of its constituent layers.

The article describes the construction of a volumetric fluid supply observer in pumping systems. The electric drive of the pump unit uses an induction motor with a squirrel-cage rotor. The rotation speed of the electric motor is adjustable. A centrifugal pump is used to pressurize a pipeline. Requirements for the automation level of pumping units are growing, so the research topic is relevant. When constructing the observer, the double squirrel cage induction motor model in a fixed coordinate system is used. The impeller rotation speed and the pump resistance moment were estimated based on the Luenberger observer. The observer is used to identify the volume flow. It is based on a centrifugal pump model using approximating coefficients of a Second-Degree Polynomial function. The article provides the dynamic characteristics of the reference model and observer. As a studies result, an error in the steady state operating mode of 1% was determined.

The article discusses a method for determining the axle box generator efficiency. The generator is installed in the axle box of the freight car. It is driven by a wheels pair. The axle box generator provides power supply to freight car systems: diagnostics, geolocation and telemetry. To determine the efficiency, an indirect method of determining the mechanical power transmitted to the axle box generator is considered. The electromagnetic torque is determined through the induction electric drive model parameters of the generator. The article describes an experimental unit. It consists of a test generator, an induction electric drive, and an open platform frequency converter. The converter control system was created in MexBios Development Studio software. Oscillograms of generator tests are presented.

The paper considers the influence of the heat carrier temperature variation in supply and return pipelines on the efficiency of the gas tube hot water boiler operating in the heat supply system and on its surfaces temperatures. The temperature dependence graphs of the convective bundle tube wall and flame tube on the ambient temperature have been constructed. The basic calculation formulas used for the calculation as well as the temperature graph of the heat supply system operation depending on the ambient temperature and the temperature of the heat carriers are presented. The heat supply system operation modes, under which the convective bundle surfaces are subjected to the low-temperature corrosion, have been determined.

The research relevance on improving the thermal energy recovery efficiency of gas turbine technology is caused by the need to reduce the fuel and energy consumption when generating the electric energy. The research objective is to define the technically and economically feasible heat recovery ratio of exhaust gases after gas turbine in the heat regenerator. The optimization problem of the heat potential recovery process was solved. The algorithm to calculate the optimal temperature of heating the air supplied to the combustion chamber of the gas turbine unit was developed. Methods of mathematical modelling of heat exchange processes, methods of choosing the rational option in solving the optimization problem, and mathematical methods of solving the optimization problems were used in the paper. The influence analysis of the optimal air temperature required for burning the fuel in the combustion chamber on the technical and economic efficiency of the Siemens SGT-100 gas turbine equipment was carried out. The expediency of applying the performed studies results of practical application in designing and operating gas turbine machines was substantiated.

Article discusses approach to development of linear magneto-electric drive using slow-moving electromechanical converter with permanent magnets Design of electrical complex uses solution of problem of optimization of linear magneto-electric motor design according to criterion of maximum developed traction force. The law of force change is implemented sinusoidal with constant component, frequency of oscillations up to 10 Hz. The weight and size and electromagnetic parameters of the linear magneto-electric drive are refined using the finite element method. The article presents the results of calculation of the main geometric parameters of the magnetic system.

The paper proposes an approach to the creation of an energy-efficient slow-moving linear magnetoelectric drive of a long-stroke single-stage piston compressor. The problem of optimal design of the magnetic system of the magnetoelectric motor of reciprocating action satisfying the criterion of the maximum of the developed electromagnetic force while ensuring the minimum mass of the active materials used is solved. A mathematical model for calculating the dynamics of a linear magnetoelectric drive is presented and the results of modeling dynamic starting characteristics are presented.

Comprehensive approach to improving heat exchangers for heat recovery and utilization of heat power installations is achieved by applying a step-by-step heat exchange process to be implemented in multi-section heat exchange equipment. Determination of its optimal structural, design and layout parameters can be carried out taking into account various criteria, including the use of the thermal efficiency function. Expressions for the thermal efficiency function of the objects under study are obtained in the form of complex, non-uniform heat exchange systems, on the basis of which the method for evaluating their execution options is developed. Optimal sequences of heat exchange sections, heat load distribution and operating modes for this equipment are determined.

The work is aimed at solving urgent tasks – improving the efficiency of electrothermal micro-thrusters (ETMT) for microsatellites weighing up to 50 kg. The purpose of this work is to evaluate the effectiveness of a small-sized ETMT with Autonomous heating element (AHE) with a diameter of 4 mm on the basis of experimental studies. In the course of experimental studies, the ETMT temperature characteristics were determined for electrical power consumption in the range of 3-30 W using "cold" and "hot" switching schemes. The effectiveness of small ETMT with AHE diameter of 4 mm is a significant increase in temperature AHE and, as a result of heating of the working fluid and reducing the time of reaching the stationary mode of operation compared to ETMT with AHE diameter of 6 mm. The results of experimental studies have shown that a small-sized ETMT be successfully used in microsatellites correction propulsion system (CPS) with a power output of 10-30 W.

The purpose of this study is to develop recommendations for low-carbon steel (0,18% C) products assembling technology using friction stir welding. Relevant information on the status of friction stir welding of low-carbon steels is presented and an analysis of existing articles is carried out. Experiments on joining plates of 4 mm thick by using the tool of different geometry are conducted. It was found that the optimum temperature when joining using WC tool is 800–950 °C. The sound welds is manufactured when using a conical pin at a tool rotation speed 500 rpm and a traverse feed rate 50 mm/min with a plunging depth of 0,05–0,1 mm and an axial force of 15–18 kN.

This paper is devoted to influence of the size and number of graphite inclusions in high-strength cast iron on pre-shrinkage expansion and, as a result, on linear shrinkage and dimensional accuracy of castings. It was established that influencing the number and size of graphite inclusions it is possible to increase the dimensional accuracy of high-strength cast iron castings by two accuracy classes and significantly reduce mechanical processing allowances of cast iron in order to save metal.

The scale resistance of the deposited steel 15N8G6M3FTB subjected to surface oxidation at a temperature of 900 °C was studied. It was established that the main increase in the mass of scale for this steel occurs in the first hours, and later this dependence is almost straightforward. The average weight gain of the metal scale of such a coating at 900 °C is 0.0128 kg/(m²·h). It has been shown that the basis of metal oxide of composition 15N8G6M3FTB is hematite Fe₂O₃ and magnetite Fe₃O₄, as well as MnO, which have weak protective properties. The number of other phase compounds with high protective properties is extremely small. The coating of steel 15N8G6M3FTB can be used for applying to the surface of parts operating at low temperatures.

The wear resistance of steel 30N8Kh6M3STYu as a result of surfacing by flux-cored wire was investigated. It was found that the average value of the relative mass wear of such a metal is 0.0002818 g/m, and the average value of the linear wear is 0.0006194 mm/m. The average value of the coefficient of friction after running in increased from 0.192 to 0.211, and the average value for the test was 0.207. The microhardness of the matrix of such a metal as a result of aging is in the range of 639–683 HV, the microhardness of the eutectic is 650–786 HV and the hardening phase is in the range of 783–882 HV. It has been shown that the steel hardening mechanism of such a system is determined by the compounds of carbides, for the most part, TiMo_0.707C_0.5, Cr₃C₂, and a small amount of TiC, SiC, intermetallic compounds, mostly Cr_0.92Mo_3.08, Fe_0.875Mo_0.125, Fe₂Ti, and a small amount of Mo₀₉₈₄Ni_0.016, Ti₃Al, Ni₃Ti, and Fe₂₄N₁₀ nitride formed as a result of aging. The established complex of dispersed phases precipitated after aging determines the wear resistance of such steel. The flux-cored wire created on the basis of 30N8Kh6M3STYu steel can be used for surfacing parts working under friction of metal on metal.

The aim of the work is to study the kinetics of crystallization of melts with complex additives. Studies have shown that microalloying alloys with complex additives leads to a change in the structure of the melt, crystallization conditions, and the release of the main and excess phases. These changes consist of a decrease in the crystallization interval of the alloy due to an increase in the solidus temperature, an increase in the rate of growth of the solid phase in the initial period of crystallization, a replacement of the mechanism of crystallization of carbides, and an increase in the temperature at which the precipitation of eutectic and hardening phases begins.

The article discusses the issue of the additive color reproduction systems control in engineering. Additive technologies provide a wide range of possibilities for the formation of a three-dimensional product with the coloring of the product in mass. However, there is no technology for color management and control of distortion of the color formation of the cured material. In the course of the study, a method of color management in the process of manufacturing a three-dimensional model using CJP (Color Jet Printing) or Binder Jetting technology is proposed to ensure consistent color communication in the CAD system "program – 3D printer – material". The notion of the additive system in engineering is implemented. According to the developed technique the performance of the color gamut of the additive system on the basis of plant ZPrinter 450 are specified.

The design of a device for filter elements regeneration is presented without disassembling the filters in which they are installed. A distinctive feature of the device is the use of a preliminarily vacuumed chamber designed to discharge contaminants from the surface of the filter element. This makes it possible to increase the operation time of the filters before they are disassembled in order to clean the filters on special stands or replace them. The efficiency of the device in production conditions is shown by the example of cleaning an aqueous solution of peat hydrohumate by powder filter elements.

The analysis of widely used dependencies for determining the mechanical characteristics during steel cutting is given. Based on the description of the scheme of the deformation zone when turning hardened steels, the laws of hardening and softening of the processed material are determined. It was revealed that the temperature, which leads to the localization of a part of the deformation in a narrow region of the chip formation zone, significantly affects the change in the properties of hardened steel during cutting. To describe this dependence, a thermomechanical approach is used that takes into account dynamic factors and the mutual influence of temperature and yield strength. The calculated values of shear stresses and temperatures are compared with experimental data.

Based on the justified methodological complex the study of the multilevel structural state of coatings and surface layers created by the ion-plasma modification was made. A comparative quantitative assessment of structural changes and the chemical composition of coatings by SEM, XPS, EDX methods and the physical and mechanical properties of coatings based on titanium nitride was carried out. It was found that for all variants of coating formation there is no titanium in the metallic state and, therefore, the formation of a droplet phase does not occur. Layer-by-layer XPS analysis has determined that coatings are heterogeneous in its composition in depth. It is shown that the modification of steel surfaces with a TiN-based composition can be used to form wear-resistant coatings on the working bodies of road milling machines that are actively used in the overhaul and maintenance of the highways.

The process of isothermal indirect extrusion is considered under conditions of viscoplastic metal flow, which provides the forming of high-strength nonferrous alloys. We believe that stamping is performed under conditions of strain hardening and fracture of the processed material. The deformation kinematics was established based on discontinuous path velocity fields. An expression is obtained for estimating the specific pressure during backward extrusion based on the upper boundary method. Dependencies were obtained showing the influence of the relative value of the tool stroke, reduction during extrusion, friction between the tool and the workpiece, the strain rate on the specific pressure during extrusion. The results can be used to assess the influence of technological parameters on the course of the operation.

The quality of machining of titanium alloys in the aviation and medical fields, characterized by the presence of micro vias, scales and surfacing on the treated surface, as well as the level of roughness is important in the manufacture of key parts. The quality parameters of the treated surface are influenced by many factors - cutting modes (cutting speed, depth and feed), cutting tool parameters (geometry of the cutting part, hardening coating, sharpness of the cutting wedge, etc.), technological equipment parameters (rigidity and accuracy), etc. The aim of the work was investigation of treated surface of titanium alloy VT1-00 when milling with small thicknesses of the shear layer, commensurate with the sharpness of the cutting wedge of the cutter. Method. The method of investigation of the treated surface during milling of titanium alloy on the micro level with the use of standard and high-quality carbide cutting tools is proposed. Results. Operating experience of the received carbide tool has shown that sharpness of a cutting wedge influences quality of the processed surface characterized by microwaves, scales and burrs, also by the roughness of the treated surface. On the basis of carried out researches it is established that for maintenance of conditions of normal cutting and chip formation it is necessary to provide sharpness of the cutting wedge characterized by the conditional entered radius of a blade rounding having values less than values of the sizes of grains of a processed material, that is r_e < 5 μm. Field of application. The obtained results of work allow to substantiate the recommendations on the required sharpness of carbide cutting tools used for milling of titanium alloys at the micro level. Conclusions. Experiments on the study of the process of cutting of titanium alloy VT1-00 at the micro level to determine the effect of cutting tool sharpness on the quality of the treated surface (microwaves, scales and burrs), allow to form recommendations on its initial state and determine performance.

The article is devoted to the study of the relationship between climatic conditions of construction, installation and repair during the operation of industrial technical systems and the structure and properties of welded joints of structural steels. It has been established that the main technological factor affecting the crystallization of the weld metal from the melt is the heat input transmitted by the heating source - an electric arc, during welding at all intervals of the formation of one-piece joints. The research results made it possible to justify the conditions under which the formation of one-piece compounds occurs. The frequency ranges of controlled heat input, that maintain a specified set of welded joints mechanical properties are determined.

The paper studies the effect of parameters of a thin-layer copper-based coating applied by magnetron sputtering on the wear resistance of samples made of steel 18Cr2Ni4WA when working in a friction pair "18Cr2Ni4WA – cast iron GG 15". The rational values for the thickness of the applied copper coating are determined, at which the lowest friction torque during the burn-in period and the minimum burn-in time are achieved. Jeol JCM-5700 Scanning Electron Microscope is used to study the friction track of samples and counter bodies. It is found that in the process of friction, the coating is selectively transferred from copper to the surface of the counter body, which significantly reduces the wear of the counter body.

The range of rubber-cord products used in industry is quite wide. Their design includes determination of parameters during calculation and subsequent tests confirming their reliability, operability and properties. It is equally important to assess the stress-strain state (VAT) of a structure during operation, which allows to understand the accident rate, make a timely decision, collect statistics for effective development of new structures and improvement of old ones. The VAT control methods offered today have a number of drawbacks: the short service life of measuring and sensing elements, their introduction of errors in the operation of the structure, and often the inability to measure, for example, when working in aggressive media. The aim of the work is to evaluate the possibility of using brass powder L63, obtained by high-speed processing, in the elastomeric composite. To achieve the set goal it is necessary to solve the following problems: to make samples from the mixture with the addition of powder L63 and without it; to compare the samples from the received mixtures on the strain-sensitivity coefficient; to compare the samples from the specified mixtures in the process of mechanical loading on the breaking machine with simultaneous registration of electrical resistance. The results: Studies were conducted on the possibility of using ultra-dispersive powder L63 to improve the electrical properties of rubber. It has allowed to increase the coefficient of strain-sensitivity in 5-7 (in comparison with classical electroconductive rubbers), keeping their mechanical properties. Sensitive elements made of such a rubber mixture will give an opportunity to create "smart" composites, as well as to control the stress-strain state. Based on the results of these studies, the Act of Implementation has been issued.

This paper presents an overview of current world developments in the field of low-energy plasma propulsion systems for small micro - and nanoclass spacecraft. A promising direction of thrusters for devices of nanoclass are propulsion ion propulsion. The use of electrical energy and high-frequency electromagnetic radiation eliminates the problem of significant power losses, because at this level, the laws of optics (reflection and focusing of waves by metal surfaces and dielectrics) and electrical conductivity (energy transfer through metal conductors) work. This fact is an advantage of plasma installations over thermal ones.

This paper presents the results of an experimental study of the velocity of ionized nitrogen flowing from the working chamber of an experimental sample of the primary accelerating system of the ion engine into the vacuum space. The main method of research was chosen calorimetric method. The design of a small spacecraft jet propulsion system with ionized gas acceleration in the high-frequency gap of a microwave generator is proposed. The object of the study is a prototype of the primary ion engine accelerator system with a solid-state microwave plasma generator and an accelerating gap. The study showed that a 3-watt microwave generator together with a pulsed voltage source of an accelerating potential difference of 1 W at a nitrogen consumption of 2.5 mg/s creates an ion jet whose speed reaches 30 km/s.the Current of the ion jet was 2-2.5 mkA. The field strength of the accelerating potential difference was 4450 V / m.

This work is devoted to identifying the patterns of influence of the Lubstab series stabilizers manufactured by LLC NPF Khiminvest on the technological, physicomechanical and thermophysical properties of porous rubbers based on styrene-butadiene rubber with the addition of azodicarbonamide as a porophore. It was found that the addition of the Lubstab 05 stabilizer allowed us to obtain vulcanizates with higher porosity as compared to other samples. A 7% decrease in apparent density as compared to the standard was achieved.

The article considers the features of changes in the radio-absorbing properties of an elastic absorber with a change in the dispersion of a functional filler. The technology of preparing the absorber and filling the covers of amplifiers in the microwave range is described. The results of the analysis of carbonyl iron powders by the methods of X-ray phase analysis, laser diffraction, scanning electron microscopy are presented.

It has been shown that a decrease in the particle size of carbonyl iron by mechanical activation helps to reduce the frequency unevenness.

A new approach is proposed to study the processes of heat and moisture propagation during drying by electromagnetic radiation. It consists in the fact that transient processes preceding the constant drying speed mode are excluded from the calculations. Thus, the initial boundary value problem for two related parabolic equations can be replaced by two independently solved boundary value problems for elliptic equations. On this basis, a numerical algorithm was developed to study the temperature and moisture content fields when drying samples of arbitrary shape. It can be used in all cases where transients are not of interest.

The article developed a mathematical model that describes the morphemic description of the structure of nouns in the Uzbek language. The developed model takes into account all forms of word-forming suffixes, affixes and creating word forms that belong to the lexical category of nouns. For the created mathematical model of word forms, an algorithm for morphemic parsing and determining the pre-ownership of word forms using finite automation is developed.

The article discusses the approach to encoding information based on families of orthogonal polynoms. The discrete signal is represented as a superposition of orthogonal polynoms. This approach allows to be transmit the useful signal in a chaotic container without matching the parameters of the noise generators. Different orthogonal functions families are considered: trigonometric functions and, Lagrange polynomials. The parameters of orthogonal polynoms families have been studied to increase the stability and stealth of the signal. The computer experiment is made. The average number of decoding errors is calculated depending on the numerical integration step. Orthogonal polynomials require significantly larger calculations to decode the message.

The application of the de Rham current theory for matching forms of images is considered. The determination the measure of differences between simplicial complexes of forms does not imply a point bijective correspondence between the structures of objects. The RKHS method for obtaining object shape metrics is proposed. The study of the forms of objects is proposed to be carried out by forming test vector fields. Simplicial complexes of objects can be supplemented by the functions of the elements representing the signals. To improve the accuracy of matching the forms of the source and terminal images, the original image is subjected to preliminary affine transformation. The minimization of the functional of the squared distance between the image forms is carried out on the basis of the QPSO algorithm.

The authors of the article analyze the impact of information security threats when conducting online surveys with an uncertain number of respondents. The article discusses threats to change responses of experts and block responses of experts. Finding the probability of making an erroneous decision using the methods of probability theory is a very difficult task. The authors propose using the Monte Carlo method as a solution. A software module that implements this method has been developed. We obtained the dependence of the probability of making an erroneous decision on the probability of changing the answers of experts, the probability of blocking the answers of experts and the number of respondents. The authors showed that there are critical values for the probability of changes in the responses of experts. These values determine the boundaries of ranges with different characteristics of the dependence of the probability of making an erroneous decision. The authors proposed two methods for finding one of the critical values. In conclusion, the authors formulated conditions that reduce the probability of making an erroneous decision.

Statistic tests created in the 20^th century may be mapped with some equivalent artificial neurons. As a result, a network of dozens of artificial neurons that combines dozens of known statistic tests may be used for the validation of the normality hypothesis. The quality of solutions made by a neural network depends on a number of used neurons (tests). This tendency gives rise to the task of creating new statistic tests (neurons) that first and foremost require low correlation of their decision with known tests. The paper presents a forecast of attainable confidential probabilities for the validation of the normality hypothesis for a small sample of 21 tests in a network consisting of 21 artificial neurons, where each one is mapped with one traditional statistic test. When new tests are used (that should be created in the 21^st century), the correlation of data is expected to lower by far, which should allow an approximately 10-fold decrease in a number of error probabilities.

One of the necessary conditions of ensuring the quality of deep hole drilling during manufacturing pieces from hard-to-machine metals is chip control. It can be ensured by applying harmonic oscillations to a drill bit in the direction of rotation axis. One possible way of maintaining such vibrations is to use a vibratory drilling head which contains an elastic element. This element allows axial displacements of the tool. If stiffness of the elastic element and the machining parameters are chosen correctly, self-actuating of axial vibrations of a drill bit in compliance with regenerative effect may occur. It is advisable to add control response, which is determined in the feedback loop, to this mechanism because of the significant damping in the cutting zone. The control response maintains the required process characteristics to ensure chip control. The algorithm of vibratory drilling dynamics adaptive control has been examined in this paper. The additional impact, which is proportional to axial speed of the drill bit, is supposed to be made on the vibration system according to this algorithm. The feedback gain is determined in the adaptation loop comparing the current value of peak-to-peak displacement and its target value. The dynamics modeling of closed loop non-linear system "elastic system-machining process-control system" has been carried out. The graphs of vibratory drilling integral characteristics plotted against processing characteristics and vibratory head parameters have been presented in this paper. These graphs are based on the multivariant modeling. The influence of the adaptation algorithm parameters on the quality of vibratory processing has been also studied.

In the article the problem of increasing the information reliability in electronic document management systems is formulated, and mechanisms for controlling and correcting spelling and errors with semantic values are developed on the basis of a combined multilevel morphological analysis with n-gram models, a typical search, recognition, and classification tools. Mechanisms for verifying the spelling of a word on the basis of a vector representation of variables and comparison with a standard analogue are proposed according to the principles of using statistical, natural, structural, technological, semantic information redundancy. The solutions to the problems of increasing the information reliability based on a set of keywords, phrases, terms by comparing with virtual, frequency dictionaries located in the electronic document database and knowledge base are obtained. A technique has been developed to optimize control mechanisms and correct spelling errors based on the use of logical, semantic and structural - technological links, cross-relationships between individual or groups of words, phrases in the text information. The obtained tools to increase the reliability of the texts of electronic documents are tested in real condition, the results are compared with the conclusions of the system experts.

The development of algorithms for constructing hybrid intelligent monitoring and decision-making systems, optimization of problem solving with fuzzy initial information, analysis of the correspondence model of complex difficult to formalize processes is considered. The main difference between the proposed development and the traditional ones is the use of modern intelligent information technologies for the development of algorithmic tools for constructing hybrid intelligent monitoring and decision-making systems.

The problems associated with the development of gas fields bounded by aquifer systems are considered in the paper in order to increase gas recovery and determine the key parameters of the reservoir for further development. To conduct a comprehensive study of the process under consideration, a computer model has been developed that is described by a differential equation with variable coefficients under corresponding initial and boundary conditions and moving boundaries. An arbitrarily defined region is converted to a standard one using the dummy region method. Functional dependences of the parameters of porosity and permeability are constructed by the method of local approximation given at some defined points in the reservoir for each nodal point. An algorithm is developed for solving the problem using the methods of longitudinal-transverse scheme and the flow option of the sweep method. The results are shown as isolines. In this paper, an attempt is made to prove that in the practice of fluid production it is advisable to introduce development technology based on inhomogeneous formation parameters. Numerical experiments have shown that using this technology wide opportunities appear for finding highly effective design solutions for fields development.

Identification of static voltage load characteristics is not a trivial task. It is extremely difficult to develop a single methodology that will allow achieving the required accuracy results for any input data. The authors made an attempt to solve the problem, developed a method based on the use of methods for processing large data sets – BigData. One of the most important stages of this method is the stage of cluster analysis. The problem of choosing a method of cluster analysis also has nuances: it is necessary to maintain a balance between time and accuracy of calculations, while performing calculations with sufficient accuracy on various data. A number of domestic and foreign authors have investigated this issue, but the proposed options cannot be used in the developed methodology. The purpose of this research is to develop a cluster analysis method that will satisfy the above requirements. The author's method is based on the k-means method. The main feature of the author's method is the mechanism of initial generation of cluster centroids, which allows to exclude the influence of random generation of two-dimensional coordinates imperfection and to achieve uniform generation of initial clusters centers. The developed method was tested on a model problem with all known solutions, which can be easily verified analytically. Also the method was tested on actual industrial load data. The results obtained the requirements of accuracy and calculation speed and allow us to conclude that the developed method of cluster analysis can be used in the task of identifying static voltage load characteristics.

A technique has been developed for interpolating the experimentally obtained scattered data using radial basis functions, which can be used to study the constraints of kinematic, power, energy, economic and other parameters in construction, road and hoisting-and-transport machines, as well as their working patterns. The technique consisting of two computational steps arranged as two separate algorithms allows the design and machine working process parameters to be optimised. The technique can be used for the range of machine parameters with an arbitrarily large dimensionality. For the first time, detailed block diagrams of algorithms are presented for interpolating scattered data using radial basis functions. At the first stage, the weighting factor determination is performed for the radial basis function method in each experimental point of scattered data. The second stage involves the actual interpolation or extrapolation of the function value at a given point with arbitrary coordinates. The developed methodology allows rigid interpolation of scattered data, such as the field experiment values of various working parameters for the construction, road, hoisting-and-transport machines and their design parameters. The data space dimensionality for the experimental points is unlimited and can be arbitrarily large.

A bicriteria customer order scheduling problem is investigated in the context of the axiomatic approach of the Pareto set reduction proposed by V. Noghin. We construct families of the instances with various structures of the Pareto set and theoretically analyze the Pareto set reduction.

The article considers the possibility of using a fuzzy first-order Takagi-Sugeno-Kang type controller to control the movement of an inverted pendulum in order to achieve dynamic stabilization of its unstable equilibrium. The structure of linguistic variables and the base of rules for such a fuzzy controller are proposed. Graphs of changes in the controlled quantities (horizontal carriage displacement and angle of deviation from the vertical) and the control action are constructed, they illustrating the onset of dynamic stabilization of the unstable equilibrium of an inverted pendulum.

The authors suggest a new approach to develop measurement data compression algorithms. According to that a data frame is considered as a bit sequence formed into a two-dimensional well-ordered linear structure. It is supposed that there is no explicit bind to the source data / specifications width within the collected structure. The researchers propose block compression algorithms. They take into account not only the relationship between one sensor readings in adjacent samples, but also the connection of the samples in one frame so that it is expected to contribute to higher compression efficiency. The studies of the proposed compression algorithms have shown that they can be effectively used for compressing data frames of information-measuring systems. The mid-compression ratio of the proposed block compression algorithms falls in the range 8.0 to 9.5, and a simple adaptive algorithm observed in the paper provides the maximum value of the average compression ratio.

The aim of this work is to obtain expressions to calculate the probability of the occurrence of binary palindromes in a finite equally probable combination of zeros and ones. The classical definition of probability is applied in the calculation of the probability of the occurrence of binary palindromes. The key results of the study are presented in the form of two theorems. Furthermore, the consequences of these theorems and characteristic examples of calculation of the probability of the occurrence of the palindromes are considered. All formulated statements are supported by proofs. The main results of the work can be used when analyzing computer data stored in a binary code.

The article discusses the estimation of fuzzy regression parameters when specifying various membership functions, since the effectiveness of the least squares method dramatically reduces when a number of prerequisites for its use are violated, in particular, when the sample being processed contains observations that are poorly consistent with the others. In these cases, one can use estimation methods that are less sensitive than the least squares method to specification errors and allow one to obtain so-called fuzzy estimates. Among such methods is the method of smallest modules, the implementation of which leads to the problem of linear programming.

The development of methods and technologies for the automatic determination of the psychophysiological state (PPS) of a person is an actual scientific and technical task. Early detection of the fact that the subject is in a sleepy state or in a state of intoxication at the workplace will help to avoid accidents, harm to life, health, and causing losses. In this work the EEG data of 30 subjects in normal, sleepy conditions and a state of mild intoxication were collected. As a result of the spectral and correlation analysis of the EEG data features were selected. An amount of information about the difference of the investigated states contained in the features was determined. A computational experiment on the recognition of human state according to EEG data based on the "naive" Bayes classifier was conducted. The following error level was achieved: 10.9% when recognizing the state of "norm" and "intoxication"; 0.2% when recognizing the status of "normal" and "falling asleep."

In the present paper the class of digraph groups is introduced by analogy with the prominent class of "graph groups". Digraph groups implicitly present in the previous work by the author on the automorphism groups of graph groups. The structure of transitive digraph groups is described in terms of the Levi decomposition into the semidirect product of the Steinberg groups and the nilpotent radical.

Mathematical model and computational experiments to solve the problems of bending of three-layer plates of complex configuration are considered in the paper. Mathematical model and computational algorithm given in the paper are developed on the basis of the Hamilton-Ostrogradky's variation principle, the Bubnov-Galerkin methods and the Rvachev R-functions. Numerical results of the problem are presented. Results are given in tabular and graphical form. Numerical studies of the results obtained are analyzed using the R-function method in combination with the Bubnov-Galerkin variational method to solve the problem of calculating the vibration of three-layer plates of complex configuration.

In work the method creation of the interpolation formula which is bringing closer function of the smoothing gap, meeting in solutions of one-dimensional tasks with a heatmass transfer is investigated. Interpolation on the basis of the decision for the smoothing gap is used for creation of finite-difference schemes to multidimensional tasks with ruptures of the first sort in boundary and initial and regional conditions. Use of additional knots with the constructed interpolation gives considerable reduction of approximating viscosity in finite-difference schemes for the convective and diffusive equations of transfer. For the constructed interpolation in case of existence of an internal interface which thickness less step of a regular grid is conducted an accuracy research at the asymptotic approximations in small parameters corresponding to changes of required function in the neighborhood of a thin interface.

The carried-out numerical calculations on a heat and mass transfer for a test task in two-dimensional rectangular area on the basis of the developed method show increase in an asymptotic order of accuracy of numerical decisions to the second from a grid step at application of the known schemes in the wide range of small parameter of diffusion.

The main topic of the article is the actual problem of organizing purposeful movement. The problems of coordinating the interests of organizers and participants of the movement, building incentives, goals, and decision-making procedures are considered. A simulation model of cars movement along the route graph has been developed. The route graph is linked to the map of Omsk. Simulation experiments were conducted. The simulation model is implemented in JavaScript. The model uses a prize function and a sample for routing. The results of simulation experiments demonstrating the influence of the sample parameters and the prize function on the time and cost of achieving the goal, the value of prizes are presented. The developed simulation program can be used to analyze purposeful movement along a directed graph in systems for various purposes.

A large amount of online news on various topics is being posted on the Internet. One of the tasks of processing this data is to provide the user with appropriate methods and tools for quick and easy search for important and interesting news. An approach to solve this problem is the reasonable distribution of news into respective classes. This increases the importance of automated classification of an electronic document section. In this paper, we consider the task of multi-class text classification for the texts written in Uzbek. The articles on ten categories were selected from the Uzbek "Daryo" online news edition and a dataset was developed for them. When performing multi-class text classification for this dataset, the following 6 different machine learning algorithms were used: Support Vector Machines (SVM), Decision Tree Classifier (DTC), Random Forest (RF), Logistic Regression (LR) and Multinomial Naïve Bayes (MNB). A detailed technological description of the stages of the proposed functional scheme of text classification and developed software is given. The TF-IDF algorithm and word-level and character-level n-gram models were used as the feature extraction methods. When defining hyperparameters for text classification, 5-fold cross-validation was used. Experiments were conducted and the highest accuracy was 86.88%. The models and methods that are proposed in this paper can be successfully used in the classification of texts written in the Uzbek language and further research in this area.

A three-dimensional mathematical model and numerical algorithm for the process of heat-moisture transfer are considered in the article, taking into account such factors as heat dissipation and moisture release in a natural product, the effect of changes in temperature and humidity of the environment on storage and drying of porous agricultural products. The developed model and numerical algorithm make it possible to predict the changes in temperature and moisture content at arbitrary points of the porous body, and serve to prevent the loss of quality and spontaneous combustion of materials under solar radiation.

In this paper we describe equivalence classes generated by finite graphs in the graph theory language without equality predicate. These classes coincide with classes of so called hard extensions of graphs.

Kapovich, Myasnikov, Schupp and Shpilrain in 2003 developed generic approach to algorithmic problems, which considers an algorithmic problem on "most" of the inputs instead of the entire domain and ignores it on the rest of inputs. Myasnikov, Ushakov and Won in 2008 constructed a simple generic algorithm for the word problem in some finitely defined semigroups, including classical semigroups with undecidable word problem: Tseitin semigroup, Makanin semigroup and Matiyasevich semigroup. But this algorithm does not work for wider classes of semigroups: for example, semigroups with one relation. In this paper we present new generic algorithm for a wide class of finitely defined semigroups, including Tseitin and Makanin semigroups, semigroups with one relation. This algorithm can be viewed as advanced development of the Myasnikov-Ushakov-Won algorithm. Also we adopt our generic algorithm for the word problem in some finitely defined groups, including classical examples of groups with undecidable word problem. The work is supported by Mathematical Center in Akademgorodok, the agreement with Ministry of Science and High Education of the Russian Federation number 075-15-2019-1613.

Kapovich, Myasnikov, Schupp and Shpilrain in 2003 developed generic approach to algorithmic problems, which considers an algorithmic problem on "most" of the inputs instead of the entire domain and ignores it on the rest of inputs. This approach can be applied to algorithmic problems, which are hard in the classical sense. The problem of checking identities in algebraic structures is the one of the most fundamental problem in algebra. For finite algebraic structures this problem can be decidable in polynomial time, or hard (co-NP-complete). In this paper we present a generic polynomial algorithm for the identity problem in all finite groups and monoids with elements of period greater than 1. The work is supported by Mathematical Center in Akademgorodok, the agreement with Ministry of Science and High Education of the Russian Federation number 075-15-2019-1613.

We study Diophantine equations over direct powers of groups and semigroups and prove that any direct power of a finite semigroup (group) with zero (resp. with the equational domain property) is weakly equationally Noetherian.

In this paper we propose a new Bayes-Minkowski proximity measure that can be used to process correlated biometric, biomedical, and other type of data (with the normal distribution law or close to it). The Bayes-Minkowski measure is an antagonist criterion with respect to the Minkowski measure, since it shows opposite properties. It is possible to build a hybrid network of classifiers and apply immune learning algorithms to the network based on these proximity measures. It was demonstrated in the work on the example of tasks of identification and verification of a person's personality by facial image. The achieved errors probabilities of person's identification and verification by face features were: 0029 и 0.0017, respectively.

A system of two coupled singularly perturbed reaction-diffusion equations is considered. A cascadic two-grid algorithm of high accuracy based on a uniform with respect to small parameters convergent difference scheme for such problem has been developed. To increase the accuracy of the difference solution by an order, the Richardson extrapolation method was applied. The results of some numerical experiments are discussed.

Nowadays, energy consumption in the world is growing becomes relevant to solve the problem of replacing traditional sources with alternative ones. The solution to this problem is impossible without preliminary forecasting of energy production by alternative sources. In this paper, we consider the problem of solving the problem forecasting electric energy by solar power plants, considering the influence of external factors (weather conditions) using a model implemented on the basis a neural network.

This article is about placement of interconnected facilities (equipment) in a plane on parallel lines with forbidden zones. Placement of the facilities inside of the forbidden zones is not possible. The facilities are connected to each other and with the zones by some communications. Communications (routing of communications) between the facilities and between the facilities and zones which are placed on different lines (adjacent lines) pass through a fixed vertical component (viaduct). It is need to place the facilities on the lines such a way that the total cost of communications between the facilities and zones will be minimal. There are many practical applications of this problem in science and techniques, for example, when designing engineering devices. Some properties of the problem are formulated. A mathematical model of integer nonlinear programming of the problem is constructed. It is shown that algorithms for solving of a problem with rectangular metric without the viaduct can be used for solving of the problem under consideration.

The problem of numerical integration of a function of one variable with large gradients in the region of the exponential boundary layer it is studied. The problem is that the use of composite Newton-Cotes formulas on a uniform grid leads to significant errors when decreasing the small parameter ε, regardless of the number of nodes of the basic quadrature formula. In the paper it is proposed to choose nodes based on minimizing the error of the composite Newton-Cotes formula. It is proved that the minimum error is achieved on the Bakhvalov mesh, while the error of the quadrature formula becomes uniform in the small parameter ε.

The question of the application of formulas of the numerical differentiation of functions in the presence of the exponential boundary layer is investigated. The problem is that the application of classical formulas, wich are based on the differentiation of the Lagrange polynomial on the uniform mesh in this case leads to significant errors. It is proposed to study the formulas for derivatives on the Bakhvalov mesh, which is widely used in the construction of difference schemes for singularly perturbed problems. It is proved that applying of classical difference formulas for derivatives on a Bakhvalov mesh have error estimate that is uniform with respect to a small parameter. The results of numerical experiments are presented.

In data analysis, presenting the boundaries between the classes of objects is considered a minor issue in most cases. However, the subsequent use of the analysis results (for example, in diagnostic tasks or in the acquisition of the necessary object properties by controlling the parameters) should be based on the boundaries delineation and the accuracy of their description. This underlines the need to develop and use universal methods for presenting the data analysis results. This paper considers the data model for applied decision support systems, in which one of the components is graphic data, i.e. domains in multidimensional space, bounded by general surfaces. A mathematical model is proposed, which outlines the range of possible graphic applications rather strictly. The paper proposes a meaningful approach to describing the boundaries delineation error. The material considered can serve as a basis for technology of data analysis results storage and use.

In this paper, we studied the surface morphology of aluminum nitride films obtained by magnetron sputtering intended for use in electronic devices. The main problem with this method of film formation is the large surface roughness of the film; therefore, the task to be solved is to improve the surface quality of aluminum nitride films by smoothing the surface roughness.

Computer modeling of magnetization behavior of thin ferromagnetic Ising films separated by antiferromagnetic film was carried out. Metropolis's algorithm was used for the simulation. Finite-dimensional scaling theory has been used. Phase transition temperatures were determined by Binder cummulants. Systems with different number of layers in ferromagnetic and antiferromagnetic film have been investigated. Temperatures of phase transitions in ferromagnetic and antiferromagnetic films are determined. A phase diagram of the system has been constructed. There are four phases on the phase diagram. Phase for implementation the spintronic devices is defined. The distribution of magnetization and chess magnetization across the layers of the system in different phases has been investigated.

Mass spectrometric analysis of closed-volume gases of quartz resonators-thermostats emitted by the materials used in the installation of the device. A measuring complex with a vacuum of 10⁻⁵÷10⁻⁶Pa has been developed. The mass spectra of the residual gases were obtained before the depressurization of the products in the DIL-14 housing. The temperature range of the study is 20÷160 °C.

The article is directed to improving the metrological characteristics of the previously investigated multi-element planar electro-induction sensor of the components of the electric field intensity vector. For this purpose, its mathematical model is made and analytic expression is obtained for error taking into account design parameters of sensor responsible for its error in nonuniform field and spatial range of measurement. Using mathematical model, geometric dimensions of sensitive elements of sensor are optimized in terms of minimum error and maximum of spatial measurement range. This allowed the following technical results to be obtained. At optimal parameter b = h/L (h - spacing between edges of sensor and electrode, L-linear dimension of sensor) of sensor error from field nonuniformity does not go out beyond 3% in all spatial range 0 ≤ a ≤ 0.2 (a = L/d; d-distance to field source). Thus, the sensor can be used for measuring at distances from the source of the field d equal to five linear dimensions L (d ≈ 5L).

As part of this work, a simulation model was constructed to evaluate the print quality of three-dimensional objects using a 3D printer. A study was conducted using non-contact scanning of a 3D model and varying the parameters affecting print quality, followed by an assessment of the degree to which the printed 3D model corresponded to its standard using software. The result of this study is the obtained values of the optimal printing parameters of the 3D model, which allow to obtain a high estimate of the degree of correspondence of the printed 3D model to its standard, and, consequently, high quality printing on a 3D printer.

We model numerically the process of a thermally activated decay of a metastable state over a low barrier in the overdamped regime. This process is typical for the recent nanoscale experiments reported in the literature. Within the framework of a novel unified computer code, two ways of modeling are applied: (i) the partial differential equation (Smoluchowski equation) and (ii) the stochastic ordinary differential equation (Langevin equation for the generalized coordinate). The advantages and disadvantages of both approaches are discussed and analyzed. Special attention is paid to the transient stage of the process yet the quasistationary stage is considered as well.

The chemical composition of cenospheres have been studied by the methods of physical and chemical analysis. The products of their interaction with water and solutions of hydrochloric acid, sodium hydroxide and sodium chloride have been determined. It has been established that cenospheres dissolve in aqueous solutions regardless of pH. Pre-treatment of cenospheres in water and solutions of hydrochloric acid and sodium hydroxide reduces their dissolution in sodium chloride solution. Calcium ions, bicarbonate ions, silanol and aluminol groups of the surface participate in the ion exchange.

Silicon dioxide films prepared by the sol-gel method from a solution based on tetraethoxysilane by spin-coating and subsequent thermal annealing in the temperature range from 200 to 600 °C are considered. The transmission spectra of the pure and impregnated with methyl orange silicon dioxide films are studied. It was found that the transmission of the all films depends on the annealing temperature and the impregnated films have the lower transmission than the pure ones. Studying the transmission difference between the pure and impregnated films in the band at 464 nm, corresponding to the highest absorption of methyl orange, it was determined that films annealed at 400 °C have the highest porosity.

An analytical approach is presented that allows one to determine the influence of the scandium concentration on the input electrical impedance of piezoelectric transducer based on aluminum scandium nitride. The scandium concentration dependences of the properties aluminum scandium nitride affecting on the transducer impedance were determined by means of the approximation of the dependences obtained from their experimental values for various Sc concentration. Based on the frequency dependences of the impedance the influence of Sc concentration in Al1-xScxN piezoelectric layer on the frequencies of the serious and parallel resonance of the unloaded and loaded transducer has been established.

The results of studies of the dependence of the mechanical stresses of aluminum nitride (AlN) films obtained by direct current magnetron sputtering on the formation modes: substrate temperature, discharge power, ratio of nitrogen and argon fluxes at a pressure of 0.07 Pa are presented. It is shown that the minimum mechanical stresses are observed at a substrate temperature of 573-613 K, a power of 900 W and a gas ratio of 4/5 - 5/5, and are (15-22) * 10⁸ N / m2.

The aim of the study is to increase the efficiency of solar cell elements on the basis of thin films of amorphous-nanocrystalline silicon, by incorporating silicon nanocrystals (Si-NPs) into a film of hydrogenated amorphous silicon (a-Si:H). The purpose of the operation is to work out optimum deposition modes of amorphous silicon films. An obstacle here is the occurrence of dust particles affecting the properties of the resulting films. As well as increasing the overall efficiency of photocells due to the creation of single-crystal quantum dots (nanocristalites), which will play the role of centers of flow of parasitic currents. The obtained samples were studied using physical methods of analysis (Raman light scattering, study of the band gap).

The results of works aimed at studying the influence of a flat-layered heterogeneous medium on the type of directional pattern of elementary wave emitter are presented. It was found that a change in the thickness of the frozen soil layer leads to a change in the directional characteristics of elementary emitter. The largest changes in the type of radiation pattern are observed when the thickness of the frozen / thawed layer is a quarter of the wavelength in this medium. It is shown that a change in the type of radiation pattern is also associated with the radiophysical characteristics of the underlying surface on which the antenna is located. The obtained results can be used in the process of optimizing the operation of antenna-feeder devices in conditions of changing the state of the underlying surface.

The thermal decay of a metastable state over an asymmetric cusped barrier in the regime of overdamping (strong friction) is considered. This seems to be of importance for the nanoscale experiments on pulling polymeric molecules. The decay process is simulated numerically through computer solving of the Langevin equation. The quasistationary rates R_D, as well as the mean lifetimes and transient times, are extracted from the numerical time-dependent rates R_n(t). The impact of the backscattering on the value of R_D is discussed. The approximate analytical decay rate is derived for the asymmetric cusped barrier. The numerical results are confronted with this formula and with another analytical formula (the integral Kramers rate) available in the literature.

The boom units of a mining shovel are structurally complex metal structures of large dimensions. Traditional methods of design calculations for such structures are based on beam-type structural models, while the actual configuration is taken into account by introducing complex built-up sections which include sections of pipes, sheets, and ribs. The correspondence of such beam-type structural models has not been systematically studied yet, which leads to crack initiation and destruction of structures on the one hand and to an unreasonably high use of metal on the other. As a result of numerical analysis of the boom units in three-dimensional statement, the actual errors of beam-type structural models in characteristic sections of structures in the most complex design cases of mining shovel loading have been determined and analysed.

Torque converters are widely used in the transmissions of self-propelled vehicles for various purposes on wheeled and tracked chassis. A significant drawback of torque converters compared to mechanical transmissions is their relatively low efficiency. Therefore, the task of ensuring high efficiency values of torque converters in the entire range of gear ratios has been of importance since the invention of these hydraulic machines. Torque converters have the lowest efficiency values in the torque transformation mode among low and medium gear ratios from 0 to 0.7. In addition, the nature of the change in efficiency for an integrated torque converter in automatic transition to the fluid coupling mode also usually decreases sharply. This article discusses a number of motor and tractor torque converter designs aimed at obtaining high values of efficiency in the range of small or medium gear ratios. The considered technical solutions are associated with a reduction in energy losses when the working fluid enters the pump wheel of the torque converter.

Actual problems are applied issues that are related to vibration isolation of machine assemblies and operator seats in machines. The publication presents some technical solutions of vibration isolator systems. These systems are simple in design and include elastic elements with a linear stiffness characteristic, but with a special arrangement to the vibration displacements of the protected object. In systems of vibration isolators "with leap" in a specific range the effect of quasi-zero stiffness of the support is realized with an ideal vibration isolation of the object. Technological and universal technical solution for the vibration-isolating seat of transport machine operator is described in the publication.

The paper deals with the planar problem of vibration isolation. The active vibration damper is mounted on an oscillating mass with a vibroactive unit at a point that does not coincide with the mass center and the action of the vibroactive force does not coincide with the mass center. An active dynamic vibration damper is an electrodynamic drive in which the translational movement of the moving mass is carried out according to information about acceleration from an accelerometer mounted on an oscillating mass with a vibroactive unit. The paper gives an assessment of the vibration isolation effectiveness, depending on the mismatch with the mass center of the vibrational force application points, the settings of the active damper and accelerometer.

Currently, there are no sufficiently effective submersible vibrators for the implementation of a promising technology for vibro-seismic impact on oil and gas reservoirs. In this paper, we consider the possibility of using a downhole elastic wave generator based on a two-stage centrifugal nozzle for the vibro-seismic impact technology (VSIT). The equation of non-stationary fluid flow through the nozzle has the form of a nonlinear Van der Pol differential equation. In this paper, when using the method of studying this equation in the Matlab/Simulink application package, the principal possibility of tincture of a well generator to the dominant frequency of an oil reservoir is shown. The result of the study showed that when using an automatic control system, taking into account the hydraulic flow and pressure transmission line, the elastic wave generator can be controlled by the generation frequency with the accuracy necessary for vibro-seismic action on oil and gas formations.

The paper reflects the results of the study conducted to determine how a free rotary instrument cuts narrow joints in asphalt pavements required for road construction. Based on the analysis of strength characteristics of different asphalt concrete grades, we developed a mathematical model of working process, and this model stands as the calculation basis. The mathematical model associates the main parameter — cutting resistance force — with the material strength values and geometrical characteristics of the working body and the working process. The results of experimental confirmation of mathematical model reliability are presented in the paper.

Planar four-bar linkages are widely used in various automatic devices and equipment; therefore, kinematical synthesis methods should be developed in order to reduce the amount of initial data and derived the exact solution using modern mathematical methods. The method of the best quadratic approximation of a function was applied to derive the optimality criterion through the well-known equation for closing a vector contour for four-bar linkage. The obtained mathematical model of kinematical synthesis can be used also to determine the singular positions of the mechanism that can cause a spontaneous change in the law of motion of the output link. Modeling of the proposed kinematical synthesis method using Mathcad confirmed the correctness of the mathematical model and allowed plotting the graphical diagram of connecting rod curves.

Precompaction of soil and construction materials used as the open storage areas foundations makes it possible to increase their bearing capacity. It ensures the stability of the material assets stacks of the foundation soil and their safety during the standard storage period. The research objective is to select and provide a theoretical basis to the technology of constructing the material assets open storage areas foundations. The design of the open storage area foundation and the operating element of its construction are proposed. Theoretical dependences describing the influence of the operating element design parameters on the characteristics of the soil foundation compaction are obtained. The analysis of the obtained dependencies makes it possible to define the operating element design parameters rational values for the particular soil conditions of the material assets open storage area.

The paper presents the design of an adapter to launch several spacecraft. The adapter is a multifaceted composite lattice anisogrid shell. The technique for creating a finite element model of the presented lattice adapter is developed. The influence of structure parameters on the fundamental frequency of oscillations is studied. The results of solving the stability problem for flat lattice panels of the adapter during compression and bending are presented.

The study is devoted to the analysis of contact stresses distribution in a two-roll module. The results of the study of the theory of contact interaction in two-roll modules are presented: an analytical description of the curve shape of the roll contact and determination of the relationship between tangential and normal stresses. Mathematical models of the roll contact curves and the friction stress models in a generalized two-roll module are determined. The obtained models are general in the sense that they are applicable for partial cases of interaction in two-roll modules. Formulas are found for calculating the neutral angles of two-roll modules. Dependencies between the forces acting in the rolls and the stresses distributed under the influence of these forces are stated. It is revealed that these dependences do not change with a change in the angle of supply of the material layer to the line of centers and the angle of inclination of the upper roll relative to the vertical.

The stress-strain state of the rubber tire of the track roller of the caterpillar mover is determined when considering the problem with an absolutely rigid rim and with an elastic rim. The effect of the rim elasticity on the radial stiffness of the track roller, on the distribution of contact pressure, and also on the distribution of the specific strain energy, which is a criterion for the fatigue strength of rubber, is shown. Two cases of the interaction of the track roller with the track are considered. The first case corresponds to the location of the axis of the track roller parallel to the chain link, the second case, when the plane of the track is located at an angle relative to the axis of the track roller. The influence of the angle of inclination of the support surface on the stress-strain state of the external rubber tire of the support roller is shown. The mechanical properties of a rubber tire are described by the elastic Treloar potential, the rim material of the track roller is considered linear elastic material.

Using two-point Hermite splines, the reference spatial trajectory of a payload on a non-rigid pendulum suspension of an overhead crane was set as a combination of plane controlled oscillations in two mutually perpendicular movement directions of the bridge and the trolley. Under the absent uncontrolled payload oscillations, payload, suspension point coordinates and the rope deviation angles were calculated. Using the example of a constant spatial trajectory of the payload bypassing a single obstacle in the absence of uncontrolled oscillations, the payload mass effect on the forces acting from the side of the bridge drives and the trolley was investigated. The time dependences for horizontal components of the drive side forces were determined using an overhead crane simulation model developed in the Simscape Multibody Matlab application. Payload of various masses was repeatedly moved along the reference constant trajectory by rigidly setting the bridge and trolley movement trajectories. By virtual sensors, the forces acting from the drives on the bridge and trolley were evaluated. The payload mass effect on the maximum values of drive forces is established to be linear. The results can be used in the design and development of intelligent mechatronic control systems for overhead and gantry cranes.

Payload uncontrolled oscillations arising during movement of a loaded self-propelled crawler crane at a construction site were reduced by equipping the crane with two additional compensating ropes equal in length and connecting the rotating platform to the load gripping device. This also increased the stability of the entire system. The stability margin moment was used to evaluate the crane stability at individual tipping axes of the crawler support contour. While moving along a random microrelief surface, under the varied length of the compensating ropes and the platform rotation angle, the length reduction increased the mathematical expectation of the stability margin moment for the most loaded lateral tipping axis. The smallest values of the stability margin moment were obtained at the platform rotation angle close to 90 degrees, with the crane stability index being most affected by the compensating rope length. At a zero platform rotation angle, the compensating rope length effect on the stability at the most loaded lateral axis was insignificant. The regression equation of the average stability margin moment affected by the compensating rope length and the platform rotation angle was obtained. The results can be used in the design of advanced self-propelled cable electric crawler cranes.

Oscillograms of changes in the accelerations of amplitudes, phases and oscillation frequencies under the action of specified loads at the input and output of the test sample of magnetorheological elastomer are recorded and analyzed. At the input, the sample is loaded with a smoothly increasing harmonic force arising from the imbalance of the unbalanced rotor of the electric motor. At the output, the sample is loaded with a magnetic field created by a neodymium magnet. A comparative analysis of the accelerations and oscillation phases of the test sample is given. An actively controlled damper based on a magnetorheological elastomer has been developed.

We considered the formulation and solution of the forced oscillations hydroelasticity problem for a three-layered circular plate contacting with a viscous incompressible fluid layer, the pressure in which varies according to the harmonic law. The plate is the bottom wall of a narrow channel completely filled with a viscous fluid. The axisymmetric coupled hydroelasticity problem consisting of the plate dynamics equation, the viscous fluid layer dynamics equation, and their corresponding boundary conditions was investigated. We obtained the plate dynamics equations taking into account inertia forces in the radial and normal directions in the framework of zigzag kinematic theory. In these equations, the load was expressed by the stresses of the viscous fluid contacting with the three-layered circular plate. The fluid dynamics equations were represented by the Navier-Stokes equations and continuity equation written for the case of creeping fluid flow in a channel. We obtained the forced radial and bending hydroelastic oscillations equations of the circular three-layered plate using the perturbation method. The solution of these equations was represented by a series of eigenfunctions of the corresponding Sturm-Liouville problem. We have also presented the numerical study results of the radial and bending vibrations amplitude dependence on the frequency for the main steady oscillations mode of the plate.

The analysis results of longitudinal and cross bends of screws of rotational pumps is carried out. Check of the offered model of cross-bending of the screw both taking into account, and without thread is executed. The interrelation of bend of the screw and decrease in the moment of inertia of its cross-section is revealed and the model of calculation of the screw on stability in pitch considering these parameters is received.

Anisogrid structural elements offer significant advantages over conventional stringer-stiffened analogues due to an exceptional strength and stiffness of unidirectional composite ribs, which are used as the main load-bearing elements. The paper presents a numerical solution for buckling of a sandwich cylindrical shell with composite lattice core loaded with hydrostatic pressure. To model the buckling of the shell, the finite element method is used. A parametric analysis on the effect of the number of helical ribs and the orientation angle on the critical hydrostatic pressure is performed. It is revealed that the local, global or coupled buckling modes can be realized in the buckled shell depending on the geometric parameters of the lattice core structure. The parameters at which the shell provides the maximum mass efficiency are determined.

The problem of longitudinal wave propagation in a cylindrical body in the presence of an incompressible external medium in a length limited area is solved in the paper in a one-dimensional statement. Along with the non-uniformity of motion, the friction force arising on the contact surface directly depends on the parameters of propagating waves. Numerical results are obtained using the finite-difference method according to the Wilkins scheme for axisymmetric problems. The results of wave propagation in a cylindrical body with a rigid external medium frame limited in length are presented. According to the calculation results, an increase in wave parameters (stresses and particle velocity) over time and with distance are observed as well as the causes of stress increase mechanism in the cylinder; the effect of external load parameters and physical-mechanical characteristics of the cylinder on the parameters of propagating waves are determined. Waves arising from active friction and reflected from the boundaries are revealed and the effect of location and length of external medium on changes in wave parameters in the cylinder is revealed.

The soil compaction process by a vibratory drum is performed during a slow horizontal progressive movement and high-frequency vertical movements of the vibratory drum by a vibration exciter. Let's consider the process of a single vertical movement of the vibratory drum into the soil on a horizontal compacted surface. As a result of the vibratory drum progressive movement vertical movements take place on new horizontal areas of compacted soil. The problem of the vibratory drum cylindrical surface vertical indentation into the soil is first presented in a differential form. The stress distribution law as per the soil depth is set taking into consideration the compacted soil layer thickness h₀ and general soil deformation modulus E₀. The relative vertical deformation of elementary soil columns according to Hooke's law is determined as the ratio of the vertical movement of the vibratory drum elements to the thickness of the layer to be compacted. The analytical integration of equations connecting the vertical load on the vibratory drum with elementary forces of the soil reactions on the vibratory drum bearing surface has been performed. The state of soil strength under the vibratory drum is determined as the initial state σ₀ and additional state Δσ, caused by an increase of the soil strength due to the compaction σ=σ₀ + εE₀, caused by relative deformation. The problem of the determination of the vibratory drum vertical movement by vertical forces has been solved. Obtained analytical dependences and method allow to construct the dependence diagrams of the vibratory drum movement into the soil on different types of soils. The problem of the vibratory drum vertical movement into the soil has been analytically solved on the basis of the deformation of vertical soil columns in the form of Hooke's law using the general soil deformation modulus E₀. The vertical interaction of the vibratory drum with the soil has been formulated as the equilibrium problem of the vertical reaction forces along the contact arc. Finite integrals have been obtained connecting the vertical load on the vibratory drum with the parameters of the soil and vibratory drum. The calculation method of the dependence diagrams of loads on the vibratory drum and vertical movements (settlement) of the vibratory drum into the soil has been developed.

A portable instrument has been introduced in the construction industry of the Russian Federation for the determination of soil strength grades, which is based on the free weight falling principle. Until the present the theory of such instrument hasn't yet been completely developed and needs to be improved. In this study on the basis of the theorem on normal stresses on surfaces of a cone to be penetrated into the soil, a logically justified theory of the instrument basic parameter selection has been developed. Stresses on horizontal areas of construction soils are equal to twice the stresses on inclined areas of the cone. At the end of the working section of a rod to be penetrated into the soil there is a round flat punch, which area is A=1 cm². During the punch penetration into the soil by an impact method, a soil compacted cone body appears before the flat punch, which is affected by normal pressure forces and tangential friction forces. For the first time the equation of normal stresses σ₁ has been obtained on inclined areas of the soil cone. The mathematical model of the instrument doesn't contain soil parameters, that allows to recommend it for any soil and media. The obtained analytical dependences allow to design similar instruments in order to measure the soil strength using any value of the falling weight mass. In this paper the instrument parameter justification has been made with the impact weight mass m₁ = 2.5 kg.

The article is devoted to the urgent problem of the resource increasing of the brush working equipment of a communal machine. To increase the resource of the brush working body, it is necessary to provide the recommended area of the contact spot of the brush bristles with the surface to be cleaned. This can be done by using a brush position control device. The results of the study of the effect of bristles deformation on the area of contact between the brush working equipment and the surface being cleaned are presented. A variant of the position controlling device of the brush working equipment of a communal machine providing the recommended area of the contact spot between the bristles and the surface being cleaned is proposed. A design diagram of the deformation of the brush working body is presented. As a result of the interaction process analysis between the brush working equipment and the surface being cleaned a relationship is obtained connecting the area of the contact spot with the deformation of the pile. A graph of this dependence is constructed. As a result of the work performed, a relationship is determined that allowing to determine the value of the contact area of the brush working equipment with the surface being cleaned for various values of the bristles deformation taking into account their wear.

Stresses in soil are a link between all parameters and operation modes of a vibratory roller and deformations at different depths of the soil. The paper presents a research technology and the results of measuring stress amplitudes in soil at depths of 0.15, 0.3, and 0.5 m at different dynamic moduli of soil deformation E_vd. It is established that in the surface layer (0.15 m deep) within a single loading cycle, the duration of stress buildup phase is 1.5...2 times lower than the duration of stress relief phase, and this ratio increases with compaction. Within one roller pass in the surface layer (0.15 m deep), the increase period of the amplitudes of separate stress cycles is 1.2...2 times longer than the decrease period of those, and this ratio also increases with compaction. It is established that the vibration impact of a roller, similarly to the impact loading of soil with a tamper, affects how the stresses change during the relief phase at each impact cycle. This change is the same as how the stresses change during the relief phase in a surface layer (0.15 m deep), which confirms that it is possible to apply the provisions of the dynamic theory of plasticity not only for impact, but also vibratory and vibro-impact soil compaction modes. The obtained results can be used to update and verify the existing and future mathematical models of soil compaction with vibratory rollers.

Rheological modeling of how the elements of a vibratory roller during soil compaction interact with each other allows the optimization of parameters of the roller and soil compaction modes based on the study of the obtained model, as well as the improvement of the soil compaction continuous control system, and the solution of other practically important tasks. To verify the models, it is required to compare the calculation results for the models with experimental data. The paper includes the results of experimental studies of the acceleration range for the vibratory drum of the DM-617 vibratory roller during soil compaction in the steady vibration mode, when the vibration is turned on, and when it is turned off. It is established that during the compaction of the soil in question in the range E_vd = 14...25 MPa, the range of vertical movements and accelerations of the vibratory drum in the steady vibration mode does not depend on the soil density. When the vibration is turned on, the vertical movements and accelerations of the drum is 1.5...2 times higher than those of the steady mode. When the vibration is turned off, the vertical movements are increased by 1.5...2 times when passing the resonance zone, and the drum accelerations do not exceed the range of those in the steady vibration mode. The obtained results allow the mathematical models of vibratory rollers during soil compaction to be verified not only in the steady vibration modes, but also in transient modes, including passing the resonance areas when switching the vibration on and off.