The processes of formation of films of alloys of the Cr–Ni, Cr–Ni–Si and Fe–Ni systems with a stab le elemental composition by evaporation methods are considered. It is shown that due to the large difference in the melting temperatures of Ni and Cr, nichrome films are obtained by sublimation. The design of the evaporator is proposed, which makes it possible to stabilize the composition of the films. Calculations of azeotropic compositions of alloys of the Cr–Ni–Si system have been carried out. The position of the isobars of the total pressure of iron and nickel on the state diagram was determined during evaporation in vacuum. The azeotropic composition of the alloy of the Fe–Ni system was calculated and experimentally verified.

The article discusses a technique for constructing an optimal histogram filter and its modifications, taking into account a priori information about the expected probability distribution density. The main idea of constructing a histogram filter is to apply a special transformation that displays the profile of a section of any distribution law into a constant level of characteristic numbers equivalent to it. This transformation allows to determine the coefficients of the histogram filter. An estimate of the value of the number of data of a particular interval of the histogram is formed by the characteristic function of the filter containing real data and equivalent to the characteristic number. The convergence of the estimates obtained by the histogram filter to the true values of the interval probabilities is shown. Modifications of the optimal histogram filter that require less computational costs for their implementation are considered. The upper bounds of the qualitative characteristics of filters are obtained. It has been established that the optimal histogram filter, regardless of the type of distribution law, provides three times the best quality of identification (recognition) in comparison with the standard histogram estimate. The efficiency of the histogram filter is confirmed by simulations. The histogram filter is an easy-to-implement tool that can be easily integrated into any open distribution law identification (recognition) algorithm.

In this paper, the patterns of manifestation of weak localization and antilocalization in graphene with enhanced spin-orbit interaction, as well as in a topological insulator with a gap in surface states induced by magnetic impurities are studied. The parameters characterizing the manifestation of weak localization, antilocalization and crossover between them are established. Quantum corrections to the conductivity of graphene are determined in units of e²/h = 38.64 μS for various ratios between the characteristic dephasing time and spin-orbit scattering time. It has been established that with a relatively long spin-orbit scattering time, not less than 10^–10 s, it does not affect the correction to conductivity and its value is determined by the dephasing time and the times of intervalley and intravalley scattering. The effect of the spin-orbit scattering is to suppress weak antilocalization. It leads to a spin flip of the conduction electron during elastic scattering, and the interference pattern of weak localization becomes more complicated due to the mixing of spin states. The sign of the quantum correction depends on which spin state contributes the most.

The interaction of radio pulse signals in an anisotropic medium over hydrocarbon deposits has been studied. During the experiments, computer simulation of the characteristics of anisotropic media was performed. The dependences of the real, imaginary, and phase components of the characteristics of the surface impedance of an anisotropic medium over hydrocarbons on its dielectric constant, the frequency of radio pulse signals interacting with it, and the number of spectrum harmonics of the latter are obtained. Based on the research results, recommendations are given to improve the accuracy of determining the boundaries of hydrocarbon deposits using electrical exploration methods based on the use of radio pulse signals. The research results can be applied in prospecting geophysics for the discovery of oil and gas deposits.

The results of the study of air-cooled coolers with natural and forced heat removal from such powerful semiconductor devices as processors are presented. Experiments were performed in the SOLIDWORKS Flow Simulation software environment to assess the influence of the orientation of the formed thermal channels on the efficiency of heat removal from the surface of a heat-loaded element. Three-dimensional models of tower heatsinks with an installed fan and a supporting structure in the form of heat pipes penetrating fins that form horizontal (model No 1) or vertical (model No 2) air channels have been developed, which made it possible to determine the efficiency of heat removal from the processor during natural and forced convection. The developed model No 1 was rotated by 90°, which may be due to design requirements in the development of technical means. This led to a change in the movement of warm air during natural and forced convection along the vertically directed channels with an analysis of the effectiveness of passive and active cooling. The number of heat pipes has been changed from six to two for previously developed types of radiators (models No 1 and 2), only with active cooling. This made it possible to experimentally establish the influence of design solutions (the number and orientation of heat pipes) in the production of modern air-cooled coolers on the efficiency of heat removal.

The detection of low-speed objects is a challenging task. The small radar cross-section of low-speed objects varying from one-thousandths to one-tens of a square meter practically excludes a successful detection of such objects against intense clutter from static objects by existing methods. In this work we present a method of coherent compensation of clutter from static objects in the sidelobes of the spectrum. The method provides successful detection of low-speed and low-visibility objects with reflective characteristics that create signals with power comparable to the power of spectral sidelobes of the clutter. The method is based on the representation of the side lobes of the spectrum of interfering reflections not in the form of noise, which determines the limiting level of “background whitening”, but in the form of a coherent spectral structure, amenable to further compensation. The proposed method must be especially effective in complicated situations such as when detecting signals reflected from low-speed and low-visibility objects (e.g., quadcopters) versus intensive clutter reflections from metal structures and buildings.

The declared increase in spatial density of user (terminal, peripheral, etc.) radiating equipment (UE) of mobile communications up to 0.1 UE/m² in 4G (LTE) networks, up to 1.0 UE/m² in 5G (NR) networks and up to 10 UE/m² in promising 6G networks may cause an unacceptable increase in electromagnetic background and in corresponding forced risks to public health. The paper proposes a method for assessing the contribution of UE radiations to the level of anthropogenic electromagnetic background created by mobile communications. This method is based on the analysis of the electromagnetic loading on the area created by stationary and mobile radiation sources of mobile communications and determined by the area density of mobile traffic, its asymmetry in downlink and uplink data transmission, the degree of UE concentration in the observation point vicinity, the radio channels spectral efficiency, the size of base stations service areas and other characteristics. The calculated data are given, indicating that in places of UE concentration, the component of electromagnetic background formed by UE radiations may be predominant, many times exceeding the contribution of base station radiations, and determining the actual level of forced risks to public health, which requires consideration in the system of their hygienic rationing.

For a noise-reduction filter, the parameters of the manufactured device often do not fit the expected parameters during development, what is caused by the spread of the parameters of the electronic components or their parasitic parameters, as well as due to the presence of its own capacitance and inductance of the frequency response assembly. In this article, the influence of parasitic parameters of components and fasteners on the filter frequency response is considered. Utilizing the electronic simulator software, the filter parameters were modeled in the frequency range from 10 kHz to 1 GHz. Based on the simulation results, recommendations were given for optimizing the filter mounting elements and changing the inductance of low-frequency chokes.

In a four-mirror gyrotron, a wide multi-screw electron beam, being in crossed electric and longitudinal magnetic fields, drifts with a velocity v_d = E₀ /B₀ in the direction of the T-wave propagation between the resonator mirrors (co-current wave) or in the opposite direction (counter-propagating wave). In this case, in accordance with the Doppler effect, the generation frequency ω is determined from the synchronism conditions as ω ≈ kω_l(1±β_d), β_d = v_d /с. Thus, a change in E₀ changes ω, i. e. electrical frequency tuning is carried out. The article presents a diagram of the design of a two-beam four-mirror gyrotron. The calculations were carried out for β_d = 0.5, q = β_||/β_⊥ = 2, the interaction was carried out at the frequency harmonic number k = 1. The tuning band was 20 %. The maximum efficiency is 48 %, the minimum is 33 %. Since the calculations were performed for dimensionless parameters, i.e., having a universal character, the physical characteristics of the gyrotron at a wavelength λ = 6 mm (f₀ = 50 GHz) and a loaded resonator quality factor Q_l = 200 were as follows: electron beam current I₀ = 60 A, B₀ = 2 T, voltage U₀ = 79 kV, efficiency = 48 %.

The increased interest in utilizing uncooled thermal bolometer-type detectors (microbolometers) within the infrared or terahertz detection field is justified by their operational and technological characteristics, in particular: relatively low manufacturing cost, high detection efficiency, compatibility with silicon CMOS technology, and operation at room temperature. The performance of such detectors depends on optimizing critical parameters, which are dictated by both the geometrical design and the electrical, optical, and thermal properties of the materials used. The determination of optical parameters stands as a decisive factor in the design of microbolometer structures. This article delves into the examination of optical parameters of thin films of structural materials of microbolometer based on thermosensitive vanadium oxide film manufactured at JSC “INTEGRAL”. The investigation showcases the results of determining optical constants (refractive indexes n and absorption coefficients k) of thin films from the transmission curve by applying the reflection-transmission method. Furthermore, a comparison is carried out between the results of computer modeling of the transmission, reflection and absorption spectra – taking into account the obtained values of the coefficients n and k – and the empirical data from the in-situ experiment.

Management business processes of educational work in an institution of secondary special education, such as the planning of ideological, educational and information work, organization of curator’s work, organization and formation of culture of safe life activity, everyday life, leisure, physical culture and healthy lifestyle are considered. The business process model “Curator’s work management” in BPMN notation is presented. With the help of set theory, the output data of business process models of educational work are presented. The ontological model of educational work in an institution of secondary specialized education is developed. This model displays classes, instances, and relations between them, which allows structuring and unifying the knowledge base of the subject area under consideration. 

In the article the device of radar-tracking recognition allowing on the basis of the analysis of a design of impellent installation to define a class (type) of observable air object is considered. Determination of the class (type) of the observed object was carried out by studying the ratios of the modulation frequencies of the spectral radar portrait. The solving rule, as well as the device block diagram are obtained, allowing to define the class and, in addition, the type of the observed air object equipped with a turbojet engine. To form a posteriori probability density, the numerical method of Monte-Carlo was used. The results of the mathematical modelling, confirming the efficiency of the proposed device, are presented. 

As large amounts of data are received and accumulated, the need to create automated and automatic decision-making systems for a wide variety of tasks becomes more and more urgent. In the technical field, one of them is technical diagnostics, and in medicine, diagnostics of the human condition. Currently, dozens of computer systems for continuous vibration control and monitoring of complex rotary-type units are in commercial operation, which form time trends for 14 vibration parameters with a time step of 1–8 s for each control point at the operated facility. The functionality of a universal decision-making module is proposed, the input data of which are the parameters and characteristics of the observed object, with the required resulting output decision.

A study was conducted on the control of a person’s pulse in the normal state and while in virtual reality. It has been established that a person’s pulse can increase significantly when he is in virtual reality. In this case, there may be various stressful situations, during which the pulse sharply quickens several times. In the process of research, a person’s pulse was predicted based on several machine learning models, which made it possible to predict a person’s condition in the near future and coordinate a series of actions to prevent risks. The most suitable models were linear regression and SSA, which showed the most accurate and plausible results. By monitoring the human heart rate in virtual reality, virtual reality scenes can be classified according to the degree of their effect on the human body. This allows to take into account people with various chronic diseases and to limit their access to scenes that are contraindicated for them. The result of the research was a software package that allows to continuously collectheart beat rate data while in virtual reality from a Bluetooth Low Energy device.

The problem of forming the skeletons of halftone images with two-mode brightness histograms under conditions of changing contrast and noise is considered. On such histograms, one mode corresponds to the objects, and the other to the background. Thanks to this feature, images are relatively easy to binarize and then skeletonize. The skeleton of a region uniform in brightness is a set of thin (limited by one-pixel) connected lines enclosed within this region and compactly describing its structure. Under conditions of high contrast and low noise on the original halftone image, binary skeletonization algorithms are widely used. They are relatively simple and can be resistant to multiplicative noise that appears at the boundaries of the regions after binarization. However, when the contrast is reduced and the noise of the original halftone image is increased, the skeletons formed by such algorithms are destroyed under the influence of additive noise, which manifests itself in the depth of the regions of the skeletonized binary image. To reduce skeletonization errors in such cases, algorithms based on preliminary low-pass filtering of the original grayscale image are used. To increase the stability of the skeletons of halftone images with a two-mode brightness histogram to noise, the article proposes a skeletonization model that takes into account the presence of multiplicative and additive noise components in a binary skeletonized image. Taking this model into account, a skeletonization algorithm has been developed, which takes into account the distortions in the shapes of the areas of the skeletonized binary image as a result of low-frequency filtering of the original halftone image and allows to reduce errors in the skeletonization of halftone images.