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Electric motors are widely used in modern vehicles to drive various mechanisms (power steering, generators, starters, etc.). Normal operation and traffic safety depend on their reliability. Modern repairing technologies make it possible to obtain 70-80% of the secondary resource of the car electric equipment. The solution to the problem of the electric motor cylindrical casing panel homogenous strain is obtained. It showed that in the repair conditions by flattering or expansion-reduction, the casing diameter does not significantly affect the circumferential deformations equality. The workpiece diameter invariability does not affect the high accuracy of the grooves and flanges zones planned final dimensions. Since the tool is a roll-roller, it is universal for flattening and strain of various diameters of the casing cylinders. This is a feature of this repair method and its adaptability to the conditions of single-piece manufacture. To align the casing cylinders out-of-roundness and the dents on them, it is enough to make the operating stroke of the driven roller by 0.5-1 mm of radial infeed, which will lead to plastic tangential and meridional workpiece strain and its flattening. This process does not require large energy costs, since the strain is carried out by the tool locally, in the roll contact zone, which is of great importance in the conditions of repair workshops.

The electric strain gauges method application to the elastic compensators effectiveness assessment for the "press-die" system of C-frame (gap-frame) presses is shown. The electric Wheatstone bridge was adapted, where the one arm is used on the equal mechanical stress calibration beam, and the other arm on the section of the press frame, which experiences maximum tensile stresses. The bridge arms' active and ballast purpose changed during calibration and research. After receiving the calibration characteristic between the current on the ammeter and mechanical stresses, the stress level in the press frame was estimated using various elastic compensators aimed at reducing them. It is shown that the use of elastic compensators based on polyurethane elastomers can reduce parasitic loads in the press frame by 15-42% compared to tensile stresses arising in the frame without a compensator. It has been established that the highest compensators efficiency is observed in the range of their upsetting up to 20-30%.

Design of the planar magnetron-injection gun (MIG) forming ribbon helical electron beam (HEB) suitable for use in new generation of powerful planar gyrotrons is developed. The presented approach is based on three-dimensional numerical simulation of electron-optic system with taking into account the real three-dimensional configuration of the electrodes, beam space charge forces and such specific for MIGs factors as roughness of the emission surface and thermal velocities of electrons. Special attention was paid to the effect of particles drift in crossed electric and magnetic fields. Recommendations to diminish the velocity spread in the regimes with high enough (more than 1.3-1.4) pitch-factor are given. An analyzer of ribbon HEBs based on the retarding electric field method is proposed and optimized. The results of theoretical studies are in good agreement with the experimental data obtained at the IAP RAS by the mentioned above analyzer.

In this article, we consider the problem of assessing the cross-layer performance of wireless centralized communication networks (e.g., 5G and LTE). We consistently introduce a user web browsing model and find the relationship between the numerical characteristics of a wireless network and the network's perceived quality when users browse the pages. An optimization problem was formulated based on the results obtained. Solution of optimization problem determines the lower bound of the average waiting time for loading additional page objects for given page view probabilities and the average waiting time for the main page object loading using various scheduling algorithms at the data link layer.

Individualization of education at the university is key factor of digital transformation. Individualization of training involves considering the personal characteristics of students, providing them with services for choosing educational activities in the educational space of the university. There are technologies for construction of the educational space in now days: intelligent tutors; educational games; collaborative and project learning; personalized and adaptive learning; tools for learning analytics and educational data mining; ontologies for learning skills mining. Timetabling is key services for planning resources such as rooms, teachers, students. Multi-agent approach allows describe independent behavior of actors - student, dispatcher, course owner in self-organizing system of courses planning and selection. The model and services for events markup by the dispatcher and student courses selection and conflict resolving by the student are under review in this paper. The results of testing services at Ural Federal University are presented. The Ural Federal University has more than 36,000 students studying in 480 educational programs. The departments of 13 schools are involved in timetabling process four times in the year. The smart scheduling IT service is used for dispatch loads between 3000 teachers and thousands of rooms.

Equivalent circuits of an elementary space cell that consist of lumped elements are proposed for constructing conservative grids used in the two-dimensional analysis of structures with arbitrary distributed permittivity and permeability. The derivation of the values of lumped elements is carried out on the basis of the finite-difference form of Maxwell's equations. In this case, all values of the obtained lumped capacitances and inductances take positive values, ensuring the computational stability and causality of the algorithms. It is demonstrated that the algorithms based on the grids obtained are numerically stable for positive, negative, and zero values of permittivity and permeability. When the values of the dielectric constant are lower than the dielectric constant of vacuum, including negative ones and equal to zero, the frequency dispersion in the proposed grid corresponds to the plasma model without taking into account the motion of positive ions and collisions, which makes it possible to use this model for the numerical electrodynamic analysis of an inhomogeneous plasma.

The issue of ensuring performance with a minimum mass of electrical machines is a task for designing traction electric motors. This article discusses ways to increase the flux linkage and one of the most effective ways is to increase the flux linkage by increasing the rotational speed, since, unlike other methods, this method does not increase the phase resistance and, accordingly, the energy loss in the winding. The main energy losses in an electric machine and the influence of the rotor speed on energy losses are also analysed. Therefore, knowing the losses in the electric machine, the efficiency of the electric machine was calculated. As a result of the study, it was revealed that an increase in the rotational speed leads to a decrease in mass and dimensions, but to a decrease in the efficiency of an electric machine. The optimal values of the rotational speed must be determined for each electric machine, thereby ensuring high efficiency, minimum weight and dimensions, as well as providing the necessary traction and dynamic performance.

The most relevant issue in the field of research of battery vehicles with traction electric drive is the question of the operation of the traction battery (TB). The article discusses the characteristic features of the operation of lithium-ion batteries. The influence of changes in the operating parameters of the TB on the battery calendar life and the occurrence of negative effects is estimated. The algorithm of current limitation in the battery control system is considered. The article describes the principle of operation of the heat current limitation algorithm on the example of a mathematical model.

The article describes types of traction e-motors used in the leading wheel drive of battery electric passenger vehicles produced by different international manufacturers at the present time. The article analyzes European and Asian models of electric buses and shows a significantly increased use of different types of synchronous electric vehicles with rare-earth permanent magnets. The article analyzes drive kinematic systems used at the present, such as the ones with a single centre motor and with motors for driving each leading wheel. The range for specific powers of vehicles, as well as the most probable average value of specific powers, are determined. Electric buses with multi-motor drives and high maximum driving speeds (more than 70 km/h) have large values of specific powers. The article contains values of specific powers for traction electric motors at the rate from 0.75 to 3 kW /kg. The article describes motor operating conditions and determines the most probable operating modes. It concludes about the most optimal use of synchronous motors in the drive energized by high-quality rare-earth permanent magnets in terms of their maximum efficiency, overall dimensions and specific energy characteristics under these conditions.

This paper is based on the 1st place solution to IEEE BigData 2020 Cup: Predicting Escalations in Customer Support. We have analysed the task of this competition, talked about various potential approaches to solving this task and our approach to solving it. In addition, we analysed those features that potentially have the greatest impact on the prediction of our model, making it possible to assess the impact of factors on escalation in this particular situation.

Nonlinear optical structures based on V 2 O 3 films on Al 2 O 3 substrate were synthesized by laser ablation. Sample placed in the nitrogen filling cryostat with optical windows have operated in temperature T=70-300 K. It was irradiated by nanosecond laser pulses at wavelength of 4.8 mkm. Reduction pulse energy of 350 mkJ obtained experimentally at T=140 K have exceeded 22 times.

A comparative analysis of two types of heterostructures (1) symmetric with a single-mode ultrathin waveguide (0.1 μm thick) and (2) asymmetric with a multimode ultra-wide waveguide (1.7 μm thick). In the case of heterostructure (2) the maximum CW optical power reached is 1.6 W at 25 degrees and 2 W at –8 degrees, while the maximum efficiency reached is 54 %. Under the pulsed pump for both types of heterostructures, there is a time domain of unstable lasing.

Superconducting nanowire single-photon detector on the lithium niobate substrate was demonstrated in integrated optical configuration. New waveguides configurations for improvement of quantum efficiency are discussed.

This article presents an approach to the development of an abdominal phantom with respiratory function for robotic surgery. A review of existing similar devices is made, showing materials of various types used to manufacture phantoms of human organs. A comparison of materials for the manufacture of phantoms of the abdominal area and human liver is carried out. Suitable materials for working with ultrasound and computed tomography are identified. A conceptual model of a deformable phantom of the abdominal zone has been developed. Possible upgrades of the phantom are also proposed, expanding its functionality. For example, to synchronize the operation of the breath simulation module with the patient's anesthesia equipment. An approach to the development of movable phantoms of the abdominal zone has been formed, which is supposed to be used when creating new systems and technologies in the field of robotic surgery.

In article a computer-aided design, optimization of parameters, experimental and field studies (in mode of receiving satellite television broadcasting) of plane diffraction antennas for 3-centimeter band was presented. It was shown, that efficiency of proposed planar diffraction antenna can reach about 60%.

This paper reports the experiences obtained in using real time simulators in electric drives systems. Hardware-in-the-Loop (HiL) and Power-Hardware-in-the Loop (PHiL) are powerful techniques that are successively used for verification, validation and experimentation of electrical drive systems. A HiL simulator based on Nexys 4 DDR board with kernel FPGA Artix 7 real time simulator has been used to test scalar control method controlling induction motor. In addition, this work presents detailed modelling of sucker rod pump, and discusses implementation approach and challenges to test the sucker rod pump in PHiL platform. Experimental results on induction motor validate the effectiveness of the HiL approach and PHiL simulation results indicate the applicability of PHiL approach for testing diagnostic methods for sucker rod pumps.

The value and steer angle ratio, steering effort of the steerable wheels while operating the vehicle are determined by the steering linkage and steering drive ratio. Since the kingpins of the real vehicle have a combined slope, the trapezoidal steering linkage is a four-bar spatial mechanism, all points of which are rotated in three dimentions during rotation. The paper proposes a mathematical model of the spatial steering linkage, which allows to calculate the steer angles and its steering linkage ratio in the full range of steer angles. The spatial model provides a higher accuracy of calculations comparing with the flat model. It is proved that it is permissible to use a flat model, which is simpler, to analyze the kinematics of steerable wheel rotation with sufficient accuracy. When using a flat model, the calculation of trapezoidal steering mechanism gear ratios the fallibility is up to 35%. To calculate the power parameters of the steering, such as the effort on the steerable wheel and the total steering resistance torque of the steerable wheels, it is more appropriate to use a spatial model that is more complex but it provides high accuracy. The accuracy of the calculations is confirmed by the results of 3D modeling in Creo software.

The performed research is devoted to the development and testing of synchronization process for the electric motors of rough group stands of the hot strip mill (HSM) 1700 PJSC “ILYICH IRON AND STEEL WORKS OF MARIUPOL”. The load on the electric motors directly depends on the distribution of pre-rolled strip reductions, which was developed in the research as favourable schedule and is in accordance with analytical calculations and experimental studies in the HSM 1700 shop environment. Reducing peak loads on electric motors due to the redistribution of reductions and synchronization of their work allowed increasing the mass of hot rolled coils at the intermediate stage of reconstruction of HSM 1700 from 9 tons to 15.83 tons. It was determined by calculation that the maximum length of a slab with a basic thickness of 150 mm, which allows implementing the synchronization processes on the HSM 1700, is 9320 mm. It is shown that a further increasing in the slab length requires of additional synchronization of electric motors of HSM 1700 rough stands No. 2-4. The required power of the electric motors of the stands was determined after synchronization, taking into account the load while the pre-rolled strip was in two adjacent stands at the same time. It was found that the required electric motor power does not exceed the design value of 8000 kW.

A circuit was constructed based on a heterodyne receiver to measure the spectral characteristics of Ka-band high-power nanosecond microwave pulses. The circuit included a receiving antenna, three input waveguide directional couplers with different coupling coefficients, a variable waveguide attenuator, two coaxial-to-waveguide adapters, a microwave cable, an additional directional waveguide coupler, as well as a heterodyne receiver consisting of an electrically controlled electronic attenuator, a mixer and a local oscillator combined in one unit. The developed circuit was intended to measure the spectral characteristics of high-power nanosecond microwave pulses in the range of 35.7–37 GHz.

Two directional couplers (for the TM 01 and TE 11 modes of a circular waveguide) have been built to use on high-power nanosecond relativistic microwave oscillators. Both couplers operate between 9 and 10 GHz.

Beam-plasma technologies are currently successfully used for surface treatment of various materials, coating deposition, plasma-stimulated synthesis and decomposition of inorganic and organic compounds. The most interesting for application is a highly nonequilibrium beam plasma, because it has high chemical activity and ease of control of its parameters due to the variation of the parameters of the electron beam used for its generation. The current stage in the development of beam-plasma technologies has allowed the creation of plasma generators for various applications - from microelectronics to medicine. In this work, a beam plasma generator is described that operates at pressures of 10–50 Pa and allows the generation of a plasma with the concentration of $2\cdot 10^{16}\ \mathrm{cm}^{-3}$ and the temperature of 5 eV. The main feature of the generator is the use of a forevacuum plasma electron source for gas ionization and beam plasma generation. The effect of ion treatment from such a plasma on the optical and surface properties of polypropylene is determined. It is shown that after processing, the absorption in the ultraviolet region increases, and the hydrophilicity of the material also increases.

Materials, combining dielectric and magnetic properties, are very attractive to use in such fields of industry as RF electronics and aerospace industry, for the manufacturing of radio-absorbing coatings. The emerging trend towards miniaturization of the various devices such as unmanned aerial vehicles requires deposition of thin and light-weight films that combine magnetic and dielectric properties. In this work we propose an advanced approach to formation of such thin magneto-dielectric coatings – by the use of a fore-vacuum plasma-cathode electron source. Using the electron-beam evaporation of dielectric (alumina ceramics) and magnetic targets in medium vacuum (several Pa), we create dense multicomponent plasma, which provides the flux of the particles of gas and the target materials, allowing to deposit magneto-dielectric coatings on a metallic substrate with a very high deposition rate (approximately microns per minute), and high degree of coating uniformity. We present here our preliminary results on the electron-beam evaporation of ceramic and magnetic targets.

Ceramic-metal composite materials are promising materials of modern high-tech production. They combine a number of unique properties inherent in both ceramics (hardness, high strength, low creep) and metal (high thermal conductivity, electrical conductivity, resistance to shock loads). The current stage of technology development requires both improving methods for creating such materials and searching for new methods for their production. In the present work, the results of electron beam sintering of a ceramic-metal compact by a focused beam in the medium vacuum pressure range are presented. It is shown that by heating the compacts it is possible to achieve a uniform distribution of elements over the volume of the sintered sample.

The main features of summing the power of the amplifiers of the output stage of the radar transmitter are considered, the implementation of the phase correction in the amplification channels and the algorithm of its functioning are described, the results of experimental studies confirming the operability and effectiveness of such a concept are presented.