This work is a continuation of the studies of the interaction of an elastically deformable belt with a pulley presented in the article. If in the previous work the interaction of a flexible belt (link) with a fixed pulley was considered, then in this work the interaction of a flexible link with the leading and driven pulleys of the mechanism at the beginning of movement and in steady state is considered. As a result of theoretical studies, an expression was obtained for the coefficient characterizing the phenomenon of elastic sliding in mechanisms with a flexible link with a friction clutch. The linear dependence of the elastic slip coefficient on the thrust coefficient, defined as the ratio of the resistance force to the movement to the double initial tension of the branches of the flexible link, is noted. An expression estimating the effect of the elastic slip phenomenon on the value of the gear ratio of the actual mechanism is obtained. The condition of motion transmission in mechanisms with a flexible link with a friction clutch is considered. It is shown that when a certain value of the thrust coefficient is exceeded, slipping occurs in the mechanism instead of elastic sliding.

Regularities of the reflected signal intensity changing in time, recorded by the detector of the laser interferometer with the operating frequency of 670 nm during the inductively coupled plasma reactive ion etching in a Cl2/N2/O2 atmosphere of GaN, p-GaN and AlGaN in AlGaN/GaN and p-GaN/AlGaN/GaN heterostructures has been established by laser interferometry and scanning electron microscopy methods due to the changes in refractive indices and etching rates. During inductively coupled plasma reactive ion etching of GaN and p-GaN layers, the intensity of the reflected signal changes according to a periodic law with the thickness change period of about 144 nm, and for AlGaN layers about 148 nm, which is due to differences in their refractive indices and etching rates. During the crossing of the p-GaN/AlGaN and AlGaN/GaN interface, there is an abrupt change in the intensity of the reflected signal within 2.7–9.5 % for 20–40 s, due to changes in the aluminum concentration, refractive indices, and etching rate at the interfaces. The change in the periodicity of the interferogram, which is accompanied by a jump in intensity when passing through the etching front through the p-GaN/AlGaN and AlGaN/GaN interface, makes it possible to determine the end time of the inductively coupled plasma reactive ion etching of the AlGaN and p-GaN layers using laser interferometry in real time in AlGaN/GaN and p-GaN/AlGaN/GaN heterostructures with two-dimensional electron gas. The obtained results can be used to form microwave and power electronics devices elements which are based on the AlGaN/GaN heterostructures.

This work is devoted to establishing the effect of using rapid thermal processing (RTP) method (450 °C, 7 s) to form an ohmic contact between two layers of aluminum metallization on the electrical parameters and reliability of integrated circuits. The resistance values of contact chains aluminum-silicon, aluminum-polysilicon, polysilicon-silicon n+, aluminum-silicon n+, current-voltage characteristics of the tested bipolar transistors, as well as the results of the reliability analyses by conducting thermal field tests were chosen as the analyzed parameters of this microcircuit. Comparison of these parameters was carried out with respect to the microcircuits manufactured using standard RTP method (450 °C, 20 min) to form this contact. An analysis of the results of the resistance value of various contact chains showed that, regardless of the type of thermal treatment, all contact chains, with the exception of the aluminum-polysilicon contact chain, have almost the same resistance. By analyzing the elemental composition of the cleavage in the area of this contact by scanning electron microscopy, it was found that during rapid heat treatment, the depth of penetration of aluminum into polysilicon is 2 times less than during its standard formation due to a 2-fold reduction in the time of exposure to high temperature compared to the standard process. This leads to a lower concentration of the aluminum in the silicon and as a result to a higher contact resistance between the aluminum and polysilicon. An analysis of the currentvoltage characteristics showed that they are all identical, except for the course of the direct branch of the base current value from the emitter-base voltage. The deviation of the linear nature of this dependence in the region of their low voltage values (£ 200 mV) in the case of the formation of ohmic Al-Si and Al-Al contacts with the use of long-term heat treatments is due to the predominance of the generation-recombination current in this region associated with an increased density of traps in the depleted region and on the surface of the semiconductor. The ideal behavior of the base current versus the emitter-based voltage is maintained by applying rapid RTP method to form an Al-Al contact by eliminating traps both in the depletion layer and on the surface of the semiconductor. The tests carried out on the reliability of these products showed that it does not depend on the type of formation of ohmic contacts between the metallization layers.

In this work, sol-gel synthesis and luminescence properties of erbium and ytterbium doped BaTiO₃ (BaTiO3:Er,Yb) in porous anodic alumina are reported. Porous anodic alumina with its well-known tailor-made honeycomb structure was chosen as a template for the sol-gel synthesis of BaTiO₃:Er,Yb. Porous anodic alumina was fabricated either on silicon wafer or aluminum foil. The sol corresponding to xerogel content of Ba_0,76Er_0,04Yb_0,20TiO₃ was deposited on porous anodic alumina by spinning, which was followed by drying and heat treatment at a relatively low temperature 450 °C on aluminum foil or 800 °C on silicon. Porous anodic alumina known also as an optically anisotropic structure differed in the experiments by diameter of the pores and thickness. Evidently, all fabricated samples demonstrated a roomtemperature erbium upconversion luminescence under excitation in the continuous-wave (CW) mode with a focused 980 nm laser beam of a 200 mW diode module. Erbium upconversion luminescence is characterized by the bands at 410, 523, 546, and 658 nm, corresponding to the ²H_9/2 → ⁴I_15/2, ²H_11/2 → ⁴I_15/2, ⁴S_3/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2.

The creation of a multilevel system of interconnections in submicron integrated circuits makes it possible to reduce the electrical resistance of conductive tracks, parasitic capacitance between conductors, and increase the speed of microelectronic devices. It is proposed to form a transverse profile of the current-carrying tracks of a multilayer metallization system in the form of an isosceles trapezoid with angles at the lower base equal to 75–85 degrees. Etching of an aluminum-based alloy film is carried out in a plasma gas mixture of BCl3, Cl2, and N2 at the pressure of 150–250 mTorr and power density of 1.6–2.2 W/cm², with the following component content, vol.%: BCl3 – 50–65; Cl2 – 25–35; N2 – the rest.

As a source of random numbers, hardware random number generators are often used, the operation of which is based on randomly changing parameters of various physical processes. The statistical characteristics of such generators do not always allow their use in the field of information security. To improve the statistical characteristics, various software tools for processing the output data of the generator are used. The purpose of this work is to study the possibility to improve the statistical characteristics of a hardware random number generator by software. The investigated hardware random number generator is based on the ND103L noise diode and has a random digital sequence of binary numbers at the output. To improve the statistical characteristics, the output stream of random numbers was processed using a software method based on the calculation of high-order finite differences. This method would allow one to get a more symmetrical distribution of random numbers, as well as increase the speed of their generation. After processing, the data from the generator under study have better statistical characteristics, which is confirmed by the NIST and Diehard tests, and the generation rate has also increased by more than 5 times. The results of this work may be useful to developers of hardware random number generators who need to improve the performance of the generator.

The article introduces the results of the experimental substantiation of the possibility to use the electromagnetic shields based on powdered aluminum oxides to reduce the electromagnetic radiation energy introduced by electronic devices. To achieve this goal, a methodology has been developed for assessing the effect of materials on the electromagnetic radiation level of electronic devices, and a methodology for estimating the radius of the controlled zone of the secondary electromagnetic radiation of computer equipment has been systematized. In accordance with the indicated methods, the study has been carried out, based on the results of which it was determined that electromagnetic shields containing the composite coating based on powdered aluminum oxides and iron oxide provide suppression of the electromagnetic radiation energy of electronic devices, as well as a reduction of up to 2 times the radius of the controlled zone of the secondary electromagnetic radiation of computer equipment. Recommendations for the practical application of the composite coatings based on the powdered alumina and iron oxide have been developed. In accordance with these recommendations, such coatings can be used in the process of manufacturing or improving the technical and functional properties of electromagnetic shields designed to ensure the electromagnetic compatibility of electronic devices, as well as to solve problems related to the information security.

Radio frequency electromagnetic radiation from base stations is the main source of electromagnetic background generated by mobile (cellular) communication systems in residential areas; its intensity makes a significant contribution to the level of electromagnetic pollution of the habitat and determines the level of electromagnetic safety of the population. The previously proposed technique for estimating the average intensity of this background, based on the analysis of the territorial intensity of mobile traffic, takes into account the spatial selectivity of base station radiation in a simplified form by introducing the radiation directivity parameter U, equal to the inverse of the number of base station service sectors, assuming that the width of the main lobe of the radiation pattern is equal to the width of this sector and without taking into account the radiation directivity in the vertical plane, which determines the pessimistic nature of these estimates. The paper presents a refined analysis of the values of the parameter U for a two-level models of antenna radiation patterns, which reflects the real values of the width of their main lobes in horizontal and vertical planes, the relative levels of side lobes and the ratio of radiation power of the main and side lobes. The analysis was performed both for stationary sector antennas of cellular communication systems and for adaptive phased antenna arrays of 4G/5G systems capable of providing service using narrow beams. The analysis showed that the value of the U parameter of sector antennas is 5–15 dB less than the inverse of the number of sectors of base stations, and for narrow beams of adaptive antenna arrays, this difference reaches 20 dB. If tilt angles of main lobes of antenna radiation patterns with respect to the horizon are less than 30°, then at estimation of the average electromagnetic background intensity the inverse of their antenna gain in the main lobe can be used as the U parameter value of the spatial selectivity (directivity) of base stations radiations.

The article proposes a new algorithm for associating the tracked trajectories and newly received marks by coordinates during the secondary processing (track-while-scan) of radar information. It is known that the biggest difficulties arise when associating in dense groups, that is, when the distance between the trajectories is commensurate with the errors in measuring their coordinates. Usually, well-known methods for solving the assignment task are used, for example, the Hungarian algorithm and similar. A common disadvantage of these methods is a rapid increase (in proportion to the third or fourth degree of the number of trajectories) in the time for solving the task. The article proposes to use the “attraction” method to increase the speed of calculations. The proposed algorithm simulates the “attraction” of all trajectories to all marks and the mutual “repulsion” of all trajectories from each other (the position of the trajectories is extrapolated to the time of location of the marks.) The conditional “movement” of the trajectories is simulated step by step until a set approach to any marks happens. Comparative modeling of the attraction algorithm and the Hungarian algorithm in the case of equal number of trajectories and marks showed that the qualitative characteristics of the algorithms are approximately the same, but the execution time for the attraction algorithm grows more slowly than for the Hungarian algorithm (in proportion to the square of the number of trajectories). Therefore, with a large number of them (more than 100–300), the attraction algorithm is executed much faster. Obviously, with the corresponding adjustment of the value and dimensions of the parameters, the new algorithm can be used to solve other assignment tasks.

The KLASS computer program planned for development is designed to work as a part of the ARION-plus software package and allows you to perform an automated assessment of the reliability of electronic products, including semiconductor devices. At the stage of work planning on the creation of the KLASS program, as a module of the ARION-plus complex, the question arose about the working time allotted for the procedure for testing a computer program. The approaches described in the scientific literature used to assess the operational reliability of computer programs, taking into account their testing, proceed from the fact that the program code has been written and debugged and there are certain data on the results of testing the computer program. Software developers would like to know the predicted testing time, which ensures a given operational reliability of a computer program, even before starting work on writing program code. Based on the analysis of the experimental data on the reliability of computer programs in various fields of application, a model is proposed for determining the testing time required to ensure the operational reliability of programs. The model was used for the computer program KLASS planned for development and takes into account the programming language, the amount of program code, the speed of the computer processor, and the scope of the program. Based on the obtained model, a nomogram with two binary fields was constructed, which allows one to quickly determine the predicted time for testing computer programs.

A multithreaded convolution implementation based on block algorithms is considered. Convolution is essentially the basis of many methods that solve the problem of determining the degree of similarity or independence of two processes, in other words, when it is necessary to determine the degree of correlation. The algorithm itself is executed with a significant delay, because for its execution it is necessary to accumulate the entire signal and then process it. The analysis showed that one of the possible ways to reduce time costs is a multithreaded implementation of convolution based on block algorithms. The article shows the main features of the convolution implementation by the overlap method with addition and the overlap method with addition, as well as numerical examples. The results obtained show that the application of these methods without the use of a window function leads to significant distortions in the signal spectrum. Based on the results of the analysis, a universal scheme for performing convolution based on multithreaded processing of an input data block is proposed. This allows to achieve a good compromise between computational complexity, system architecture, and time costs.

Currently, image transfer and storage require compression. In this article, the hybrid compression algorithm is used for color/black and white images. It includes the discrete wavelet transformation and the Walsh transformation that is used for quantization. The Walsh transform coefficients are quantized and arithmetically encoded. At the output, the combined data is compressed and can be stored on any device or transmitted over any available network in the shortest time. The compressed image is decoded and the original image is decompressed using the inverse conversion operation.

The effectiveness of biofeedback training for the development of relaxation skills using the NeuroDog hardware-software complex is investigated. The relaxation skill is one of the conditions for maintaining the functional state of drivers and assistant drivers of locomotive crews at an optimal level during a working trip, and it is also one of the factors for a successful inter-trip rest. A multiple regression analysis has been carried out, which allows to predict the indicators characterizing the success of developing the relaxation skill, depending on the severity of psychophysiological and personal indicators of drivers and assistant drivers of locomotive crews. Two regression models have been constructed to explain the dependence of the indicators of developing the skill of achieving relaxation on the psychophysiological and personal characteristics of drivers and assistant drivers of locomotive crews. Models are characterized by sufficient quality. Quality indicators: of the first regression model – coefficient of determination R² = 0.71 (with F(40, 65) = 4.06, p = 0.00000027), Durbin-Watson statistics d = 1.81, of the second regression model – R² = 0.75 (with F(49, 56) = 3.51, p = 0.0000043), d = 2.09. To predict the indicators of developing the skill of achieving relaxation, regression equations were obtained depending on the severity of psychophysiological and personal indicators of locomotive crew drivers.