The problem of two-dimensional syndrome-norm decoding of iterative codes based on a library of error patterns is considered. In two-dimensional coding, sequence code is first transformed into a code matrix, and then the row and column check code are calculated. In the decoder, the error position of the twodimensional can be obtained by the operations that first calculate the syndromes and norms, then match with the error patterns in the existing library. The error pattern library is stored in the memory and generated by the subset of the error pattern. Subset patterns are generated from the base pattern using row and column permutations. The norm calculated based on the syndrome unambiguously determines the base pattern and the corresponding subset of error patterns, which reduces the search space for the syndrome to a subset. In this case, the syndrome is used as an address for retrieving a specific error pattern and correction rule from the memory. With the error rate increased, the size of the error pattern library is raised and the computational complexity of its formation is enlarged. As a result, the known methods for generating the error pattern library become non sufficient. This paper proposed a mathematical model, a generator structure, and an algorithm for fast generation of an error pattern library based on the iterative expansion of the error patterns, which makes it possible to reduce the number of generated redundant error patterns by orders of magnitude and significantly shorten the computational complexity in comparison with the known approaches.

It was suggested to form higher derivatives, including the fourth one, characteristics of non-linear elements based on altering the synchronous, phase insensitive active band-stop filter to the needed harmonic component of the researched antiderivative of the characteristic of the examined element, which is proportional to the according derivative, which allows, if needed, to reestablish the missing phase component using a synchronous, sensitive to phase demodulating filter, which is agreed to the specially formed control signals, or to exclude it using a simple amplitude demodulator. The use of the proposed shaper of higher derivatives for the purpose of determining the primary parameters of various objects with nonlinear characteristics of antiderivatives makes it possible to substantially increase the accuracy of their measurements, bringing this process to the level of tenths of a percent, which is a very important result in the measurement technique, first of all, the Q-factor of radiotechnical elements, for example, varicaps, with a wide range of its change.

The article offers a new filter for tracking a maneuvering aerodynamic target. During the process of the filter synthesis, three main requirements were considered: the filter must provide a minimum smoothing error in the areas without maneuver; the filter should ensure the minimum possible errors and emissions of smoothing error during the maneuver; filter must not contain additional constants, which take into account, for example, the value of input errors, parameters of target maneuver, period of information modification and so on. In order to meet these requirements a two-fold adjustment (variation) of the coefficients smoothing was used in accordance with the deviation of the coordinate of the newly measured position of the target (mark) from the extrapolated position. The variation is performed in accordance with the selected function, while the smoothing step acquires a certain conditional value. The proposed filter modelling has been performed. Received by modelling values of smoothing errors were compared with smoothing errors of other filters, described in scientific literature. The comparison results demonstrate a significant decrease in smoothing of the root mean square errors of coordinates and velocity in the proposed filter in comparison with other samples; with according to main requirements, any “tunes” in proposed filter were not used.

On the basis of the unconventional concept of the formation of the line spectrum of the hydrogen atom, an equation is obtained that is necessary for computer calculations of the energy emitted by an electron during the transition from a certain current energy level rλ,n to the receiver radius r0. The obtained solution of the energy equation made it possible to derive the formal relations necessary for calculating the values of the radii of the levels of the hydrogen atom and, accordingly, the velocities of the electron in these orbits. The applied aspect of the considered methodology consists in using the results of the performed calculations for the problems of synthesis and analysis of quantum-electronic circuits.

The self-heating effect exerts a considerable influence on the characteristics of high-power electronic and optoelectronic devices based on gallium nitride. An extremely non-uniform distribution of the dissipated power and a rise in the average temperature in the gallium nitride heterostructure field-effect transistor lead to the formation of a hot spot near the conductive channel and result in the degradation of the drain current, power gain and device reliability. The purpose of this work is to design a gallium nitride heterostructure field-effect transistor with an effective graphene heat-removal system and to study using numerical simulation the thermal phenomena specific to it. The object of the research is the device structure formed on sapphire with a grapheme heat-spreading element placed on its top surface and a trench in the passivation layer filled with diamond grown by chemical vapor deposition. The subject of the research is the large signal performance quantities. The simulation results confirm the effectiveness of the heat-removal system integrated into the heterostructure field-effect transistor and leading to the suppression of the self-heating effect and to the improvement of the device performance. The advantage of our concept is that the heat-spreading element is structurally connected with a heat sink and is designed to remove the heat immediately from the maximum temperature area through the trench in which a high thermal conductivity material is deposited. The results of this work can be used by the electronics industry of the Republic of Belarus for developing the hardware components of gallium nitride power electronics.

At present, with the development of nanotechnology, plasma-chemical etching remains practically the only tool for transferring an integrated circuit pattern in a masking layer to a substrate material due to the fact that the pattern transfer accuracy is comparable to the size of etching gas ions. Requirements for plasma technology: permissible defects, selectivity (material selectivity), line width control, etching uniformity are becoming more stringent and, as a consequence, more difficult to implement. To increase the rate and selectivity of plasma-chemical etching of silicon nitride films during plasma processing of a gas mixture consisting of both a fluorine-containing gas and oxygen, sulfur hexafluoride with a concentration of 70–91 vol.% was used as a fluorine-containing gas with an oxygen concentration of 9–30 vol.%.

In this paper, the results of a refined analysis of the correlation, previously discovered by the author, between the accepted maximum permissible levels (MPL) of radio frequency electromagnetic fields (RF EMF) for population and the mortality rate of COVID-19, carried out using the data samples from the World Health Organization (WHO), taken monthly from May 2020 to July 2021, are presented. To explain the results obtained, correlation between the accepted MPL for RF EMF, the level of vaccination of population against COVID-19, and the level of gross domestic product per capita in different countries were analyzed additionally. Analysis results confirm the presence of a noticeable correlation between the RF EMF MPLs and the COVID-19 mortality rate, especially in the first months of the analyzed period. The subsequent decrease in correlation between them by the end of analyzed period is a result of significantly larger efforts in struggle against COVID-19 in those countries where high RF EMF MPLs are adopted taking into account only the danger of thermal effects in human body, in comparison with countries where more stringent standards that take into account the danger of non-thermal bioeffects, are used. The first of these countries, having on average a higher level of economic development, ensured mass COVID-19 testing of population, imposition of tougher and longer restrictions (quarantines, lockdowns, etc.), as well as significantly higher rates of vaccination of the population. The presence of a confirmed correlation between these characteristics does not necessarily mean the existence of an unambiguous causal relationship between them. In countries of the first group with passive regulation of population protection from environmental factors, this principle is used not only in relation to RF EMF, but also in relation to the other factors. This determines the relevance of a deeper system analysis of the impact of the adopted legal systems for protecting the population from the entire set of anthropogenic factors on its health and collective immunity.

The purpose of the article is to describe the methodology for obtaining the structure of the optimal controller, which provides the guidance of the aircraft to the target point on the plane, using the method of time difference of arrivals (TDoA) for two navigation positions. The main feature of the system is that one measurement of time difference of arrivals between the aircraft and two navigation positions does not allow to describe the position of the aircraft on the plane fully. It describes only the line of position (LOP) in the form of a hyperbola. The aiming problem is solved by choosing a hyperbola passing through the target point, bringing the aircraft to a given hyperbola, followed by its movement along this hyperbola. In this case, the choice of the target hyperbola is a trivial task, in contrast to the task of determining the structure of the control system implementing the right and effective guidance law. The regulator obtained on the basis of the method of analytical design of the optimal regulator, according to the results of the computer simulation, showed its operability.

The paper describes an approach to design a system for analyzing and classification of a voice signal based on perturbation parameters and cepstral representation. Two variants of the cepstral representation of the voice signal are considered: based on mel-frequency cepstral coefficients (MFCC) and based on bark-frequency cepstral coefficients (BFCC). The work used a generally accepted approach to calculating the MFCC based on the time-frequency analysis by the method of discrete Fourier transform (DFT) with summation of energy in subbands. This method approximates the frequency resolution of human hearing, but has a fixed temporal resolution. As an alternative, a variant of the cepstral representation based on the BFCC has been proposed. When calculating the BFCC, a warped DFT-modulated filter bank was used, which approximates the frequency and temporal resolution of hearing. The aim of the work was to compare the effectiveness of the use of features based on the MFCC and BFCC for the designing systems for the analysis and classification of the voice signal. The results of the experiment showed that in the case when using acoustic features based on the MFCC, it is possible to obtain a voice classification system with an average recall of 80.6 %, and in the case when using features based on the BFCC, this metric is 83.7 %. With the addition of the set of MFCC features with perturbation parameters of the voice, the average recall of the classification increased to 94.1 %, with a similar addition to the set of BFCC features, the average recall of the classification increased up to 96.7 %.

One of the main stages in the design of reinforced concrete structures is to determine the crosssectional area of the reinforcement according to the requirements of strength, stiffness and crack resistance, the search for the number of rods based on the nomenclature of reinforcement, its placement in the cross section with the fulfillment of the conditions of durability, and fire resistance. The paper summarizes the experience of developing algorithms for solving the problem of selecting the optimal reinforcement of reinforced concrete elements and proposes an algorithm for optimizing reinforcement using nonlinear models of reinforced concrete elements. The proposed algorithm is implemented as a module of the software package for engineering construction calculations Beta 5.0. The article shows the results of verification of the proposed algorithms based on the results of trial operation of the module for selecting the optimal reinforcement within the activities of the Testing and Research Center of the Polotsk State University.

The threshold logic method used for electronic products when assessing their reliability in the form of predicting the performance class of products for a given operating time (K1 is a class of operable ones, K0 is a class of inoperable copies) provides for the transformation into a binary code of informative parameters obtained at the initial moment of time, and allows to build a forecasting model in the form of a table showing which code combinations correspond to the instances of the K1 class. The use of a binary transformation simplifies the forecasting procedure, but the reliability of the predictions is slightly reduced. It is relevant to obtain a forecasting model that has the simplicity of its application and provides a higher reliability of forecasting a class of products than with a binary transformation of parameters. On the example of bipolar transistors of the KT872A type, the regularities of electrical parameters used as informative ones are established, and for their transformation into a code, it is proposed to consider three areas of parameter change: the first area is the range of values between the mathematical expectations obtained separately for instances of the classes K1 and K0; the other two areas are the parameter values to the left and right of this range. Parameter values falling within the range are assigned the R code (from the word Range), outside the specified range - the code 1 (one) or 0 (zero), depending on the pattern of the informative parameter. It is explained how to convert parameters to codes 1, 0 and R and get a prediction model in the form of a logical table built from these codes. Basing on the example of the investigated transistors, it is shown that the proposed heuristic model provides the best forecasting results, practically keeping the simplicity of the basic method of threshold logic.