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The assessment of the suitability of cables of 6–110 kW with XLPE insulation in comparison with cables of the same voltage but possessing paper-oil insulation has been fulfilled on the basis of the method of multi-objective optimization that makes it possible to account not only the quantitative characteristics (of reduced costs), but also qualitative ones. As an indicator of the reliability of the cable line the maximum mean time to failure (the value inversely proportional to the parameter of succession of failures), which is an order more for cable lines with XLPE insulation than for cable lines with paper insulation, is adopted. A comprehensive assessment of the convenience of installation of cable lines revealed that the installation of cable with XLPE insulation features a 1.2–1.6 times easier installation as compared to three-wire (voltage 10 kW) and 1.4 times easier installation as compared to single-core oil-filled cables (voltage of 110 kW). The efficacy of the cables 6–110 kW with XLPE insulation is proved on the basis on the method of multi-objective optimization, that took into account as the costs for the construction and operation of cable lines and the reliability of its operation, ease of its installation and other quality indicators. If the goals taken into account are considered as equally important, the polyethylene-insulated cables for a voltage of 10–110 kW is more efficient as compared to three-wire (voltage 10 kW) and solid (110 kW) cables with paper insulation. Herewith, the cost of the cable with XLPE insulation may exceed the cost of cable with paper insulation up to two times. If the most important aim is to provide the minimum reduced costs for the construction and operation of the cable line, the use of cables with XLPE insulation for voltage of 10 kW is most advisable in individual cases.

Palm oil is comparable to traditional diesel fuel in terms of calorifi c value, stoichiometric ratio, and cetane number. However, its increased kinematic viscosity and pour point make it diffi cult to use in pure form in diesel engines. (Research purpose) To study specifi c features of burning: diesel fuel with various additives of palm oil (biodiesel fuel); pure 100-percent palm oil; biodiesel fuel with various additives of palm oil and hydrogen peroxide, as well as to develop a method to control its combustion process. (Materials and methods) To determine the ignition time lag, the authors chose a method of kinetic modeling of self-ignition of biodiesel fuel in the air. The self-ignition process was simulated using the Chemical Workbench software package. An adiabatic calorimetric bomb model was used to perform calculations. To describe the process of self-ignition, a universal kinetic mechanism was used, which was verifi ed to calculate self-ignition of diesel and biodiesel fuel surrogates, as well as the formation of toxic substances and soot in the combustion processes. (Results and discussion) It is shown that adding palm oil to diesel fuel increases its ignition time lag, especially at low and medium temperatures of 750-950 kelvin. It was determined that with addition of 10 percent palm oil, the ignition time lag of biodiesel fuel is almost the same as that of diesel fuel no more than 5 percent. Increasing the amount of palm oil additive up to 30 percent and more signifi cantly increases the ignition time lag of the fuel. When using only palm oil as a fuel, the ignition time lag in the temperature range of 800-950 kelvin increases in two times. The study determined the optimal amount of hydrogen peroxide to be used for each composition of biodiesel fuel with various additives of palm oil. (Conclusions) It is shown that additives of hydrogen peroxide can infl uence the reactivity of biodiesel fuel and thereby regulate its ignition time lag.

The paper presents the results of experiments to improve the performance of insulating paper as a component of high-voltage paper-impregnated insulation by introducing the modifying additive into the paper mass. Environmentally safe and economically feasible method of obtaining modifying additives of the chitin-glucan complex of Aspergillus niger (A.n.) which is a large-tonnage waste production of citric acid is proposed. The modifying additive was introduced into the paper mass in an amount of 5–10% to the mass of absolutely dry fiber of sulfate insulating cellulose. The paper samples were subjected to accelerated thermal aging at 140°C for 250 hours. The values of the short – term electrical strength of the samples with the modifying additive, both in the initial and in the aged state, exceeded the similar characteristic of the paper sample without additives. for the paper made of 100% cellulose after 250 hours of accelerated thermal aging the maximal mechanical tensile strength decreased by 2.1 times; for paper containing 5% HGC A.n. – by 1.5 times and for the insulating paper, which was introduced into 10% of the modifying additive, the specified parameter during the test has not changed. Comparative evaluation of the sorption activity of the cellulose component was carried out by determining the light transmission coefficient of transformer oil relative to the standard at the process of thermal aging. It was found that the modification of insulating paper by biopolymer also increases its sorption activity in relation to the products of destruction of paper-impregnated insulation components under the catalytic effect of copper., В работе представлены результаты экспериментов по улучшению эксплуатационных характеристик электроизоляционной бумаги, как компонента высоковольтной бумажно-пропитанной изоляции, за счет введения в бумажную массу модифицирующей добавки. Предложен экологически безопасный и экономически целесообразный способ получения модифицирующей добавки из хитин-глюканового комплекса Aspergillus niger (ХГК A.n.) – многотоннажного отхода производства лимонной кислоты. Модифицирующую добавку вводили в бумажную массу в количестве 5–10% к массе абсолютно сухого волокна сульфатной электроизоляционной целлюлозы. Образцы бумаги подвергали ускоренному термическому старению при температуре 140°С в течение 250 ч. Значения кратковременной электрической прочности образцов бумаги с модифицирующей добавкой как в исходном, так и в состаренном состоянии превосходили аналогичную характеристику образца бумаги без добавок. Введение в состав целлюлозной основы модифицирующей добавки способствовало повышению нагревостойкости бумаги, сохраняя показатель механической прочности на высоком уровне в процессе длительного термического старения: у бумаги из 100% целлюлозы после 250 ч ускоренного термического старения предел механической прочности на разрыв снизился в 2.1 раза; у бумаги, содержащей 5% ХГК А.n. – в 1.5 раза, а у бумаги, в состав которой было введено 10% модифицирующей добавки, указанный показатель за время испытаний не изменился. Сравнительная оценка сорбционной активности целлюлозного компонента проводилась путем определения коэффициента светопропускания трансформаторного масла относительно эталона в процессе термического старения. Установлено, что модификация электроизоляционной бумаги биополимером также повышает ее сорбционную активность по отношению к продуктам деструкции компонентов бумажно-пропитанной изоляции в условиях каталитического влияния меди.

The assessment of the suitability of cables of 6–110 kV with XLPE insulation in comparison with cables of the same voltage but possessing paper-oil insulation has been fulfilled on the basis of the criterion of reduced costs. Thus, the comparison was undertaken between cables of various design and material of insulation: three-core paper insulated ones vs. three-core XLPE insulated ones; three-core paper-insulated ones vs. solid wires with XLPE insulation; single-core oil-filled cables of 110 kV with paper insulation vs. solid wires of 110 kV with XLPE insulation. The increase in long-term permissible current loads for cables with XLPE insulation because of the larger permissible temperature of heating in comparison with cables with paper-oil insulation complies with as would increase in the cross-sectional area of cable cores (equal to 0.61 from the original) and therefore reduces the cost of the cable by reducing the cost of manufacture of conductors. The reduced costs of the construction and operation of cable lines with XLPE insulation (accounting the increase in the cost of a cable 1.2 and 2 times as compared with the cost of a cable with three-core insulation), despite the decline in the cost of manufacture of conductors and the reduced annual operating costs (9 % and 17 % respectively of cable lines of voltage of up to 35 kV and 110 kV), occurred to be more than the reduced costs of the construction and operation of cable lines with paper insulation. Currently the cost of one meter of cable with XLPE insulation is less than the cost of cables of AAB, CASB, AASv types of a voltage of 10 kV with aluminium cores, that ensures their undeniable efficacy.

The article is devoted to the analysis of modern priorities in the sphere of food industry main branches development. The author identified the most promising of them, in particular, modification of socially significant food products (fats) by means of their combination with traditional and non-traditional plant raw materials having full fat oil and low-oil content as a source of physiologically functional nutrients. Chemical composition of raw materials has been studied to reveal the biological value and food safety. The efficiency of using wheat germ flour as an ingredient of vegetable fatty composite mixtures in bread production is established. The author suggested using composites that consist of germinated wheat product, animal fat, creamy melted butter, palm, soybean and sunflower oils which have balanced fatty acids content. The author justified the relevance of heat treatment of composite mixtures having wheat germ flour content up to 30.0% of the mixture mass at 40–50 °C, more than 30% – up to 70°C during 10–15 min. That will help increase its microbiological purity, reduce the enzymatic action of germ lipase, protease and lipoxygenase, extend the mixtures shelf life up to 45 days. Optimum proportion of wheat germ flour should not exceed 70.0% of the raw material mixtures weight. It was demonstrated that 30,0 to 50,0% of solid fats can be replaced with vegetable oils. There was a positive effect of the developed composites in the amount of up to 5.0% to the quantity of flour according to the recipe on the quality of bread produced from the 1st grade wheat flour.

Kinetics of catalytic esterification of glycerol with butanoic acid on model systems was studied. Reaction orders for the reactants (butanoic acid and glycerol) were determined. They are close to 1.It was shown that the reaction order with respect to the catalyst - orthophosphoric acid - in regions where its concentration is above 0.1 mol/l is equal to zero. The estimated value of activation energy is 51.9± 8.0 kJ/mol. The results of the experiment can be used to create an industrial technological process for the synthesis of glycerol tributyrate. This compound can be used as an alternative non-phthalate plasticizer for articles made of PVC. The obtained kinetic model was validated on glycerol-containing waste of the biodiesel synthesis from renewable raw materials. The recycling of the by-product in the biofuel production with obtaining plasticizing compositions for the polymer industry can be developed on the basis of the studies.

Objective. The purpose of the article is to analyse the existing methodology used to assess the efficiency of automated information security systems by studying open literature sources, international and industry standards of the Russian Federation on information security of automated systems, guidelines and orders of the Federal Service for Technical and Expert Control of Russia, as well as departmental orders, instructions and regulations on information security at informatization facilities of internal affairs bodies. The analysis results in identifying the advantages and disadvantages of the specified methodology, as well as the possibilities of its use when conducting a quantitative assessment of the efficiency of access control subsystems of information security systems at the informatization facilities of internal affairs bodies. Methods. To achieve this goal, the method for system analysis of approaches used to assess the efficiency of information security tools and systems has been applied. Results. The paper presents results of analysing the main approaches used to assess the efficiency of tools and systems for information security of automated systems. The paper determines the relationship between the efficiency indicator of access control subsystems of information security systems and the main disadvantage of their use in protected automated systems of internal affairs bodies. The paper substantiates main directions of improving the existing methodology, proposes methods and indicators for quantifying the efficiency of access control subsystems (including those modified on the basis of using new information and communication technologies) of information security systems in protected automated systems of internal affairs bodies. Conclusion. The results obtained can be used to quantify the security level of existing automated systems and those being developed at informatization facilities of internal affairs bodies.

A schematic and structural solution of regenerative-utilization heat use in centralized heat supply systems was previously proposed in order to increase the efficiency of operation of heating networks located in non-passable channels. The impossibility of creating a full-scale experimental setup covering the required range of factors and the area of their change, the complexity of a passive experiment on existing heating mains led to the need to develop a virtual model based on the ANSYS sofware package. A six-factor experiment has been carried out on this virtual model. Regression equations have been obtained to determine the pressure required to provide air purging of the channel, as well as heat exchange with pipelines of direct and return network water located in the channel, and heat exchange with soil around the channel. In addition, a regression relationship has been derived to find the integral heat flux from the listed washed surfaces to the air flow. The transition from dimensionless to natural factors has been made in the paper. The most significant factors are identified with the help of Pareto cards. The obtained dependencies have been verified in Part 1 of the paper. The adequacy of the obtained regression equations has been determined using standard statistical estimation methods based on the calculated values of the Fisher’s, Student’s and other criteria. The response surfaces are presented and analyzed using two dimensional sections for a number of factor values at fixed values of one and a change in two most characteristic, physically significant for a given response function. They have been validated on the basis of the analysis of regression dependencies. The obtained regression equations cover almost the entire range of possible diameters of heating mains, which makes it possible to use them in the development of energy-saving projects.

The mixed problem for the telegraph equation well-known in electrical engineering and electronics, provided that the line is free from distortions, is reduced to a similar problem for one-dimensional inhomogeneous wave equation. An effective way to solve this problem is based on the use of special functions – polylogarithms, which are complex power series with power coefficients, converging in the unit circle. The exact solution of the problem is expressed in integral form in terms of the imaginary part of the first-order polylogarithm on the unit circle, and the approximate one – in the form of a finite sum in terms of the real part of the dilogarithm and the imaginary part of the third-order polylogarithm. All the indicated parts of the polylogarithms are periodic functions that have polynomial expressions of the corresponding degrees on an interval of length in the period, which makes it possible to obtain a solution to the problem in elementary functions. In the paper, we study a mixed problem for the telegrapher’s equation which is well-known in applications. This problem of linear substitution of the desired function witha time-exponential coefficient is reduced to a similar problem for the Klein – Gordon equation. The solution of the latter can be found by dividing the variables in the form of a series of trigonometric functions of a line point with time-dependent coefficients. Such a solution is of little use for practical application, since it requires the calculation of a large number of coefficients-integrals and it is difficult to estimate the error of calculations. In the present paper, we propose another way to solve this problem, based on the use of special He-functions, which are complex power series of a certain type that converge in the unit circle. The exact solution of the problem is presented in integral form in terms of second-order He-functions on the unit circle. The approximate solution is expressed in the final form in terms of third-order He-functions. The paper also proposes a simple and effective estimate of the error of the approximate solution of the problem. It is linear in relation to the line splitting step with a time-exponential coefficient. An example of solving the problem for the Klein – Gordon equation in the way that has been developed is given, and the graphs of exact and approximate solutions are constructed.

The paper proposes an approach based on the use of mathematical methods for modeling the behavior of the designed web application and user behavior. This approach allows an evaluation of the usability of this application. The paper discusses the models of user interfaces (UI), which are used to assess the convenience of site navigation. The possibility of using two classes of UI models is shown – structural-logical (ontological) and probabilistic. Models of the first class are used to assess the degree of comprehensibility of the proposed UI navigation on the search web resource in the accepted terms. For this, mathematically defined measures of similarity between the elements of the UI and their relationships and the elements of a hypothetical (but plausible) model of the user’s perception of the search area in a given subject area are used. In particular, the paper substantiates the possibility of using Jaccard and Levenshtein lexicographic distance metrics as such measures of similarity. Probabilistic models are based on Markov chains. With the help of these models, in the presence of reliable statistical data collected during the trial operation of a web application or its prototype, it is proposed to estimate the average number of user steps required to solve a specific problem of finding information about a subject area object. The paper provides some recommendations on the use of similarity measures to improve the usability of the UI of web applications. In addition, data on the technique for estimating the probabilities of transitions of Markov chains and semantic connections are presented. To clarify the features of the UI analysis models proposed in the article, the website of the RTU MIREA Admission Committee (https://priem.mirea.ru) is provided with a fairly simple organization that provides a search for information about admission and training at the University. The application of the approach described in the paper, along with traditional methods of testing the usability of UI, will increase the overall level of usability of applications, and thereby reduce the cost of identifying and correcting related errors.

The paper considers one of the numerical methods to solve problems of scattering electromagnetic waves on the systems formed by parallel-oriented cylindrical elements – two-dimensional photonic crystals. The method is based on the classical partition approach used for solving the wave equation. Тhe method principle is to represent the field as the sum of the primary field and the unknown secondary field scattered on the medium elements. The mathematical expression for the latter is written as the infinite series according to elementary wave functions with unknown coefficients. In particular, the N elements-scattered field is found as the sum of N diffraction series in which one of the series is composed of the wave functions of one body and the wave functions in the remaining series are expressed in terms of the eigenfunctions of the first body using addition theorems. Further, to meet the boundary conditions, on the surface of each element, we obtain systems of linear algebraic equations with the infinite number of unknowns – the required expansion coefficients, which are solved by standard methods. A feature of the method is the use of analytical expressions to describe diffraction on a single element of the system. In contrast to most numerical methods, this approach allows one to obtain information on the amplitude-phase or spectral characteristics of the field only at the local points of the structure. The high efficiency of this method stems from the fact that there is no need to determine the field parameters in the entire area of space occupied by the multi-element system under consideration. The paper compares the calculated results of the transmission spectra of two-dimensional photonic crystals using the considered method with the experimental data and numerical results, obtained by other approaches, and demonstrates their good agreement.

Implementation of the task of creating a digital platform for a full-featured system of information and analytical support for public administration at the federal, regional and municipal levels, requires a lot of resources and serious expertise.In this regard, the subject of the study was the experience and trends in the construction and operation of digital platforms for state and public administration. The aim of the paper was to summarize the international practice of creating, operating and developing digital public administration platforms. As part of the study, the authors carry out a systematic, content and comparative analysis of various sources: regulatory documents, scientific papers, analytical materials of a number of international organizations, etc.The article presents the results of a study of world experience in the application of various tools to support e-government and support digital governance platforms. The authors describe global trends in the use of information and communication technologies to support public administration. The paper presents a list of general principles for the operation of digital platforms, gives the results of the analysis on the compliance with these principles of the state digital platform of the European Union, highlights its distinctive properties.The article forms proposals and development directions, based on the results and available studies on the development and promotion of digital management platforms, that can help accelerate the spread of digital transformation of public administration in the Russian Federation. The results of the study can be applied to identify the potential of the existing platform, its strengths and weaknesses, including in the context of the possibilities of developing the process of digital transformation of governance, as well as effectively moving towards the formation of the digital platform of public administration in the Russian Federation.

Introduction. Various algorithms for solving fuzzy vehicle routing problems are considered. The work objective was to study modern methods for the optimal solution to fuzzy, random and rough vehicle routing problems. Materials and Methods. The paper reviews fuzzy vehicle routing problems, existing methods and approaches to their solution. The most effective features of some approaches to solving fuzzy vehicle routing problems considering their specificity, are highlighted. Results. The Fuzzy Vehicle Routing Problem (FVRP) occurs whenever the routing data is vague, unclear, or ambiguous. In many cases, these fuzzy elements can better reflect reality. However, it is very difficult to use Vehicle Routing Problem (VRP) solving algorithms to solve FVRP since several fundamental properties of deterministic problems are no longer fulfilled in FVRP. Therefore, it is required to introduce new models and algorithms of fuzzy programming to solve such problems. Thus, the use of methods of the theory of fuzzy sets will provide successful simulation of the problems containing elements of uncertainty and subjectivity. Discussion and conclusions. As a result of reviewing various methods and approaches to solving vehicle routing problems, it is concluded that the development and study of new solutions come into sharp focus of researchers nowadays, but the degree of elaboration of various options varies. Methods for the optimal solution of FVRP are limited, in general, to some single fuzzy variable. There is a very limited number of papers that consider a large number of fuzzy variables.

The paper deals with a problem of the obfuscated JavaScript code detection and classification based on Abstract Syntax Trees (AST) coloring. Colors of the AST vertexes and edges are assigned with regard to the types of the AST vertexes specified by the program lexical and syntax structure and the programming language standard. Research involved a few stages. First of the all, a non-obfuscated JavaScript programs dataset was collected by the public repositories evaluation. Secondly, obfuscated samples were created using eight open-source obfuscators. Classifier models were built using an algorithm of gradient boosting on the decision trees (GBDT). We built two types of the classifiers. The first one is the model that classifies the program according to the type of the obfuscator used, i.e. based on what obfuscator created the sample. The second one tries to detect samples obfuscated by the obfuscator whose samples are not observed during training. The quality of the obtained models is on par with the known published results. The feature engineering method proposed in the paper does not require a preliminary analysis of the obfuscators and obfuscating transformations. In the final part of the paper we analyze a quality of models estimated, discussing the certain statistical properties of the obfuscated and non-obfuscated samples obtained and corresponding colored ASTs. Analysis of generated samples of obfuscated programs has shown that the method proposed in the paper has some limitations. In particular, it is difficult to recognize minifiers or other obfuscating programs, which change the lexical structure to a greater extent and the syntax to a lesser extent. To improve the quality of detection of this kind of obscuring transformations, one can built combined classifiers using both the method based on the AST coloring and the additional information about lexemes and punctuation, for example, entropy of identifiers and strings, proportion of characters in upper and lower case, usage frequency of certain characters etc.

In this article, the authors consider the possibility of using a hybrid energy storage system to even out the load profile of the enterprise. Solving the problem of rational use of energy storage taking into account the initial variable load schedule will significantly reduce not only the cost of electricity consumption by the enterprise, but also the costs of its production. Detailed characteristics of batteries with various types of electrolytes and supercapacitors are given. A model of the active scheme of a hybrid electric energy storage system consisting of a lithium-ion battery and a supercapacitor unit with the corresponding characteristics is presented. The model was carried out by using the SimPowerSystems software in MatLab. During the simulation, the temperature and the aging effects and of the batteries were not taken into account. The selfdischarge parameter of the battery was also not presented. As a result of the simulation, discharge characteristics of supercapacitors and batteries were obtained based upon which the expediency of their combined use for leveling load profiles of various types was substantiated. The paper presents the results of the simulation of operating modes of a hybrid energy storage device, combining the advantages of two types of energy storage devices, as well as a diagram of delivered power to the network, corresponding to the specified parameters. The paper provides a mathematical description of the increasing power by hybrid storage system resulting from the combined use of supercapacitors and batteries. The paper presents the dependence of the power increase ratio on the frequency and the pulse current duty ratio, which proves that the maximum possible output power of the hybrid storage system can be several times greater than the power of a single battery having the same parameters.

Over the past few years the popularity of blockchain technology has grown significantly. It is able to make change as the economic environment, as also identifying new approaches to business management. The paper is devoted to innovative aspects that appear and have a tendency to develop in the field of accounting and audit due to the blockchain technologies development. This technology can affect entire industries, and especially the financial sector. The decision to use blockchain in combination with appropriate data analytics can help in accounting processes, as well as in conducting daily transactions involved in the audit. The transition to a financial system with a significant element of the blockchain opens up many opportunities for the profession of an accountant and the skills of the auditor will be focused more on concerning issues of a higher level. The methodological base of the study includes the theory of accounting and auditing, as well as the principles of operation of blockchain technologies in the aspect of their application in finance. The study overviews the main trends in the development of blockchain technology in accounting and auditing based on foreign scientific studies, as well as reviews of blockchain practices in articles by various scientists. The result of this research is an analysis of blockchain technologies in the finance field. The study depicts conclusions about the degree of applicability of this technology in the Russian Federation, reflects the main problems, risks and benefits from the introduction of this technology. This paper may promote an interest to the current professionals in the accounting and auditing field, as well as to professionals working in the range of building data exchange systems between employees involved in working with finances.

This paper suggests an approach to the semantic image analysis for application in computer vision systems. The aim of the work is to develop a method for automatically construction of a semantic model, that formalizes the spatial relationships between objects in the image and research thereof. A distinctive feature of this model is the detection of salient objects, due to which the construction algorithm analyzes significantly less relations between objects, which can greatly reduce the image processing time and the amount of resources spent for processing. Attention is paid to the selection of a neural network algorithm for object detection in an image, as a preliminary stage of model construction. Experiments were conducted on test datasets provided by Visual Genome database, developed by researchers from Stanford University to evaluate object detection algorithms, image captioning models, and other relevant image analysis tasks. When assessing the performance of the model, the accuracy of spatial relations recognition was evaluated. Further, the experiments on resulting model interpretation were conducted, namely image annotation, i.e. generating a textual description of the image content. The experimental results were compared with similar results obtained by means of the algorithm based on neural networks algorithm on the same dataset by other researchers, as well as by the author of this paper earlier. Up to 60 % improvement in image captioning quality (according to the METEOR metric) compared with neural network methods has been shown. In addition, the use of this model allows partial cleansing and normalization of data for training neural network architectures, which are widely used in image analysis among others. The prospects of using this technique in situational monitoring are considered. The disadvantages of this approach are some simplifications in the construction of the model, which will be taken into account in the further development of the model.

Hybrid electric powertrains in automotive applications aim to improve emissions and fuel economy with respect to conventional internal combustion engine vehicles. Variety of design scenarios need to be addressed in designing a hybrid electric vehicle to achieve desired design objectives such as fuel consumption and exhaust gas emissions. The work in this paper presents an analysis of the design objectives for an automobile powertrain with respect to different design scenarios, i. e. target drive cycle and degree of hybridization. Toward these ends, four powertrain configuration models (i. e. internal combustion engine, series, parallel and complex hybrid powertrain configurations) of a small vehicle (motorized three wheeler) are developed using Model Advisor software and simulated with varied drive cycles and degrees of hybridization. Firstly, the impact of vehicle power control strategy and operational characteristics of the different powertrain configurations are investigated with respect to exhaust gas emissions and fuel consumption. Secondly, the drive cycles are scaled according to kinetic intensity and the relationship between fuel consumption and drive cycles is assessed. Thirdly, three fuel consumption models are developed so that fuel consumption values for a real-world drive cycle may be predicted in regard to each powertrain configuration. The results show that when compared with a conventional powertrain fuel consumption is lower in hybrid vehicles. This work led to the surprisingly result showing higher CO emission levels with hybrid vehicles. Furthermore, fuel consumption of all four powertrains showed a strong correlation with kinetic intensity values of selected drive cycles. It was found that with varied drive cycles the average fuel advantage for each was: series 23 %, parallel 21 %, and complex hybrids 33 %, compared to an IC engine powertrain. The study reveals that performance of hybrid configurations vary significantly with drive cycle and degree of hybridization. The paper also suggests future areas of study.

As a result of the research, the paper shows the essential need to take into account the social attributes of processes and phenomena in economy. From the standpoint of the interdisciplinary approach at various levels of the system three-hierarchy (micro-meso-macro) in economy, the following characteristics of social attributes are considered: “economic agent”, “expectations of the economic agent” and “preferences of the economic agent” taking into account their heteromorphism and heterogeneity, “intersubjective relations in economy”, “trust” between economic agents, “institutions”. The conclusions made as a result of the study make it possible to formulate the concept of selecting tools for economic and mathematical modeling of processes and phenomena at various levels of the system three-hierarchy (micro-meso-macro) in economy. Further studies will make it possible to select the most relevant tools for each level of the system three-hierarchy from the numerous apparatus used to model processes and phenomena in economy taking into account the concept proposed in this paper.

The purpose of this article is to study possible directions and ways of developing human resources for the transition to digital economy using the potential of new technological solutions. The paper demonstrates the relationship of the Fourth industrial revolution and changes in the development of human resources, identifies key areas of the impact of digitalization processes on human resources, including the transformation of the structure of demand in the labor market changing the format of employment of workers and the emergence of new models of work changing the content of work, as well as changing the ratio of the importance of hard skills and soft skills. With this in mind, the important components of developing human resources in digital economy are identified, the emphasis is placed on the role of the education system in this process, covering the following aspects: creating a system of new professions, competencies and standards in correspondence with appropriate educational programs; incorporating innovative educational technologies into the educational process in order to develop a set of soft skills; creating a “smart” education system using intelligent ICT solutions affecting the content and process components of learning as key components of developing human resources. The paper determines the feasibility of implementing the proposed solutions on the basis of the partnership between educational institutions, public authorities and business.

Introduction. The paper considers improving the management quality of an educational organization through automating the personalized data collection, storage and ranking. The authors have developed a module of the university corporate system, an ePortfolio of students, which implements a multicriteria optimization method for calculating the students’ rating on the basis of the collected and stored data. The study object is multicriteria ranking methods. The subject of the study is the automated calculation of student’s rating within the electronic portfolio. The study objective is to develop tools for collecting, storing and processing data on individual achievements of students and the implementation of the mathematical method of multicriteria optimization for ranking students on the basis of the portfolio data. Practical implications include development of a tool for an effective management of the educational process.Materials and Methods. A prototype module of the university corporate system “ePortfolio” on the platform of 1C: Enterprise 8.3 is presented. To rank students, a special case of the alternative ranking method is implemented in the block of the data analysis module – pairwise comparison in order of their relative importance. At that, a unified scale of relations was used.Research Results. The authors described the scheme of the information system (IS) operation “ePortfolio”, presented a process interaction pattern for the portfolio formation, as well as a diagram of business processes under calculating an individual rating. A fragment of the sample is shown on which the performance of the multicriteria optimization block has been tested. The criteria of the calculations are described, as well as the rule of screening alternatives for solving for the optimum.Discussion and Conclusion. The paper presents the results of the IS block operation on ranking a list of students. The calculation results coincide with the practical data.

Introduction. Perfect polyphase unimodular sequences, i. e. sequences with ideal periodic autocorrelation and single amplitude of symbols are widely used in modern radio communications and radar. A special place among them is occupied by perfect ternary sequences (PTSs) with elements {–1, 0, 1}. In fact, these are binary sequences with the alphabet {–1, 1}, but with zero symbols in some positions. It is known that PTSs are quite numerous and their length in comparison with perfect binary sequences is not limited from above. The charge for this is a peak factor greater than one, which causes energy losses in the receiver. A large number of research papers and books are devoted to the design of PTSs and the study of their properties. In particular, the handbook on sequence design by Fan and Darnell (1996) which provides an overview of the then known PTS families has become widely famous. However, over the past two decades, numerous new PTS families were discovered, some theorems on their existence were obtained, and connections were established between them and circulant weighing matrices. Therefore, there is a need for a new review of existing PTSs.Objective. The article is devoted to a retrospective review of existing PTSs and their generation devices.Materials and methods. Considered and analyzed domestic and foreign sources of information (books, journal papers, conference proceedings, patents).Results. Along with solving an informational bibliographic problem, the review shows the relationship between PTSs obtained at different times, their connection with circulant weighing matrices, and also describes the block diagrams of generators of some PTS families.Conclusion. A brief retrospective review of PTSs for their almost 60 years history is presented and the generators of some PTS families are considered. The results of the study are relevant for use in modern radio communications and radar systems and in particular, in CW and LPI radars.

However, the ECP in its classical form has a number of significant drawbacks. One of them is a dependence of treatment modes and electrolyte compositions on the processed material. In addition, aggressive expensive electrolytes that require special technologies for disposal are used for ECP. Electrolytes in ECP often require heating to a temperature of 60–90 °C. Processing at such temperatures causes significant harm to the environment and production personnel. To eliminate the existing disadvantages of the ECP and expand its technological capabilities, a processing method with application of pulsed unipolar and bipolar modes has been proposed. As a result, fundamentally new processes of pulse ECP with a pulse duration of 0.05–20.00 ms have been developed. They provide a reduction of energy costs for the process and high efficiency of polishing in comparison with traditional DC polishing. The rate of smoothing micro-roughness of the treated surface related to the total metal removal is significantly increased. The use of pulse modes in comparison with traditional ECP allows processing in universal electrolytes of simple compositions based on sulfuric and orthophosphoric acids without addition of chromium anhydride. Application of the developed pulse modes, which will provide at low metal removal a significant change in surface roughness, is the most appropriate for the ECP of precise parts, products or parts of small cross-section and rigidity, such as medical devices for minimally invasive surgery, precision engineering parts, etc. The paper presents results of a study for influence of pulsed unipolar and bipolar ECP modes on the surface quality of stainless steel specimens, as well as a comparative analysis of the efficiency of using pulsed ECP modes instead of DC polishing. The technological parameters of ECP using pulsed modes, providing the highest quality surface polishing with high efficiency of micro-roughness smoothing and low energy consumption have been established in the paper.

Introduction. One of the classes of modern radio engineering systems are systems with spatial diversity of transmitting, receiving or transceiving elements. In such systems, an increase of the information content is achieved by signal coprocessing ensuring synchronization in time and phase of the carrier oscillation. Currently, the researchers do not pay enough attention to the requirements for the accuracy of synchronization of distributed systems of different applications, as well as simple and affordable ways to synchronize them.Objective. The paper main objective is the search for technical solutions for clock and phase synchronization without atomic frequency standards and external sources of coordinate-time information.Methods and materials. The paper considers a distributed radio engineering system with non-rigid structure. Each element of the system has reference signal from its own crystal oscillator. The oscillators are not physically aligned. The phases of their oscillations are periodically compared by the method of two-way transmission of synchronizing signals (from one element to another and vice versa). The synchronization technique (software algorithmic approach) is reduced to the coprocessing signal correction according to estimated frequency (phase) drifts. The testing of the proposed technical solution is presented on a hardware model consisting of ten receiving and transmitting modules.Results. The experiment showed that RMS of synchronization errors does not exceeded 12 degrees by phase (for VHF), or 0.2 ns by time. These results are acquired for spatial diversity up to several hundred meters, mutual speed of the modules up to several meters per second and may be extended for higher frequencies (in particular, UHF).Conclusion. The paper proposes a method of multilateral propagation to synchronize distributed radioengineering systems. Combined with software algorithmic technique this method enables to obtain synchronization accuracy in real-time sufficient for coherent diversity technique.

A new method based on direct frequency conversion is developed for measuring complex reflection coefficient of microwave two-poles. The method is based on the use of quadrature synchronous detection of the signal branched by omnidirectional probe with subsequent quadrature processing of the detected signal components. Such approach makes it possible to solve measuring task by simultaneously analyzing both amplitude and phase distribution of the field in transmission line which leads to redundancy. In addition, the use of direct frequency conversion provides the detection linearity in considerably higher dynamic range of the levels of the signal forwarded from the transmission line. So, both of these factors can improve the measurement accuracy. The method is performed by excitation of probing harmonic microwave oscillation in transmission line and formation of reference microwave oscillation with the same frequency. The reference signal and the signal branched from the transmission line by omnidirectional mobile probe are fed to the inputs the quadrature synchronous detector. At its outputs, I and Q components of the detected signal are formed. By means of these components, the amplitude and phase field distribution in the trans-mission line is obtained. It is followed by calculation of module and phase estimations using the expressions presented in the paper. The measurement result is obtained as arithmetic average of these estimations. A mathematical model of the proposed method is developed. The relations for the module and phase of the complex reflection coefficient are derived based on the analysis of both the amplitude and phase distribution of electromagnetic field in the transmission line. The paper describes the experimental unit in the form of vector measuring line that implements the quadrature method of measurement. The experimental analysis of the amplitude and phase distribution of the field in microwave path is carried out for standard loads with different parameters. Based on the analysis results, the estimations of measured parameters are calculated and measurement errors are defined. It is shown that highprecision measuring instruments can be designed using the proposed method.

Nowadays the interest in search of ways of improving the efficiency of small radar cross-section aerial objects detection and localization rises against the background of widespread use of light and unmanned aerial vehi-cles. As a result, researchers pay attention to radar systems (RS) with continuous linear frequency modulation (linear FM) signal. The use of such signals gives the measurable opportunity to reduce radar system peak-speech power and to cut the cost and weightsize parameters of the RS. The paper observes low-power ground based radar implementation prospects for purposes of detection and estimation of motion rates of small-sized aerial objects. The proposed algorithm of radar signals processing enables to simplify the detection of such tar-gets. The paper reveals the structure and defines the steps of the algorithm. The fundamental for the algorithm under consideration is the method of the range-Doppler image composition of the scanned area using digital signal processing. The paper presents the results of the algorithm operation in the low-power RS of C-band radar, obtained by processing of quadrotor echo-signals during the real experiment. The results show successful solvation of the applied problem of detection and tracking on the small-sized aerial object with the radar cross-section equal to less than 0.5 m2 and the spectrum of secondary radiation characterized by the expressed multimodality. The results of the experiment validate the application of the algorithm and demonstrate the possibility of the algorithm implementation in design of portable RS and automated target acquisition centers for detecting and tracking of the small-sized aerial targets (both, single as multi agent) with the information display on operator control panel.

Over the past decade, the Russian government has embarked on an ambitious program of economic development in the Russian Far East (RFE), envisioning the transformation of the region into a hub for trade with the Asia Pacific. This paper explores the extent of RFE’s trade integration with both key partners around the world and the rest of Russia. In particular, we calculate the region’s trade potential on the basis of mean predicted values from a gravity model using three samples that offer different perspectives. Actual trade flows are then evaluated relative to the potential and the resulting index is analyzed for various years and countries. Based on the findings of the paper, we can draw several conclusions. First, RFE exports to Northeast Asia have intensified over the period 2008–2017, allowing the region to surpass its potential, although there seems to be room to grow with respect to China. The Russian government could facilitate cross-border trade by further reducing non-tariff barriers and improving transnational infrastructure links. Second, the deepening integration with Northeast Asia has been achieved at the expense of trade links with the rest of Russia. This might appear worrisome, given the geostrategic importance of RFE for Russia. At the same time, it might simply reflect the fact that RFE’s natural resource exports are increasingly diverted to the Asia Pacific, which is more efficient than to ferry them to Western Russia, where they might end up being re-exported to Europe. Similarly, it might be more efficient for RFE to import from China than from more distant parts of Russia. Third, imports from Japan and Korea are far below potential, although these two countries can play a key role in promoting the economic development of RFE

The paper contains numerical simulation of nonisothermal nonlinear flow in a porous medium. Twodimensional unsteady problem of heavy oil, water and steam flow is considered. Oil phase consists of two pseudocomponents: light and heavy fractions, which like the water component, can vaporize. Oil exhibits viscoplastic rheology, its filtration does not obey Darcy's classical linear law. Simulation considers not only the dependence of fluids density and viscosity on temperature, but also improvement of oil rheological properties with temperature increasing. To solve this problem numerically we use streamline method with splitting by physical processes, which consists in separating the convective heat transfer directed along filtration from thermal conductivity and gravitation. The article proposes a new approach to streamline methods application, which allows correctly simulate nonlinear flow problems with temperature-dependent rheology. The core of this algorithm is to consider the integration process as a set of quasi-equilibrium states that are results of solving system on a global grid. Between these states system solved on a streamline grid. Usage of the streamline method allows not only to accelerate calculations, but also to obtain a physically reliable solution, since integration takes place on a grid that coincides with the fluid flow direction. In addition to the streamline method, the paper presents an algorithm for nonsmooth coefficients accounting, which arise during simulation of viscoplastic oil flow. Applying this algorithm allows keeping sufficiently large time steps and does not change the physical structure of the solution. Obtained results are compared with known analytical solutions, as well as with the results of commercial package simulation. The analysis of convergence tests on the number of streamlines, as well as on different streamlines grids, justifies the applicability of the proposed algorithm. In addition, the reduction of calculation time in comparison with traditional methods demonstrates practical significance of the approach.

The paper deals with a workflow of a proportional pressure modulator equipped with a linear electric motor of electromagnetic type (LEMET). A schematic diagram consisting of a power supply and control system has been constructed to determine the performance of LEMET. The power supply system is a self-contained half-bridge inverter. The converter input is supplied with 12 V DC voltage. The motor phase is powered by an inverter which includes transistor switches and diodes. The control system of the autonomous inverter consists of two channels – a current limiting channel and a linear transfer channel. The study is based on the results of numerical and simulation modeling of LEMET workflows. Numerical simulation is performed and investigated by a finite element method in the FEMM environment. Geometry of the LEMET model lies in the region of air with an electromagnetic permeability of 1. An initial radius of the grid generation for the working gap area is 0.5 mm, while for other areas an adaptive generation method has been applied. In order to determine a continuous power function at any point within a current variation interval i and a displacement x current linkage and electromagnetic force functions have been approximated by polynomials use of the Curve Fitting application. The simulation LEMET model of a proportional modulator has been built in the MatLab Simulink environment. The implicit Runge-Kutta method using the secondorder inverse differentiation formulas with a variable step has been applied for solution of a mathematical model in the MatLab Simulink system. The equation of an electrical circuit for an inductor motor phase has been compiled according to the second law of Kirchhoff. The LEMET traction characteristics have been obtained by moving a locking and adjusting element (LCE) from 0 to 6 mm in steps of 1 mm while changing the MMF in the winding from 0 to 2 A in steps of 0.1 A. It has been established that in order to move the LCE by 6 mm with the speed of 40 mm/s with a resolution of 0.15 mm, the maximum value of the current in the LEMET winding is equal to 2.5 A. In this case the value of the electromagnetic force is 120 N. This makes it possible to improve an accuracy of the brake drive pressure regulation by 12.3 %. Solutions have been proposed to increase the LEMET speedwork. Characteristics of the engine have been described and numerical parameters of LEMET have been determined in the paper. The developed simulation model allows to investigate functional properties and dynamic characteristics of the proportional modulator with a relative error of 4.07 %.

The paper explores a new research direction unfolding at the junction of modern textual criticism and modernization challenges in education. It outlines the theoretical basis for constructing a model of the «new literacy» representative of the 21st century. The paper contains an attempt to describe the main trends in the changes of text: rejection of linearity, shrinkage of text volume, orientation to «small text structures», duplicative character of different sign systems in the content reflection, increase of interactivity, feedback forms development, emergence of «new forms of authorship» and a number of other trends. Examples are given of new literature, created in the form of comics, presentations, infographics, drawn notes. The author reveals the scope of «the texts of the new nature» through the provision of its characteristics; describes two main technologies of formation of such texts; provides experimental data that characterize the process of perception of this kind of texts; and, finally, formulates priority research issues.

The article studies examples of the use of innovative technologies in the field of “Smart City”, which is a key factor contributing to the implementation of the concept of “Smart City”. The paper presents various approaches to the implementation of information technologies, analyses case studies on the management of smart cities of the world, which justify the change in the approach from isolated vertical management to integrated holistic management. The study also analyses various examples of the use of innovative technologies and approaches in the context of “Smart City”, identifies the trends in their development. At the end, the authors carried out the analysis of the domestic experience of applying the concept of “Smart City” and the results achieved.

In this paper, the problem of segmentation of halftone images is considered, in which areas of local maxima and minima (extrema) are distinguished with a monotonic change in the brightness of pixels from local extrema to the boundaries of areas. To solve this problem, a mathematical model is proposed and a segmentation algorithm is developed on the basis of counter-wave growing of local extremum regions. The developed algorithm differs from the known segmentation algorithms by using a set of brightness thresholds (by the number of regions), varying by one in each cycle, starting from the values of local extrema, taking into account the increase or decrease in brightness to select adjacent pixels that are attached to the regions formed from these local extrema. The algorithm provides a greater deviation of pixel brightness from the average value within the region compared to known segmentation algorithms. This does not allow evaluating its efficiency using known indicators based on the variance of the brightness within the region. In this regard, estimates of the monotonicity of changes in the brightness of regions are proposed based on a) the shortest distances from each pixel of the region to the corresponding local extremum along the routes determined by the maximum increase (for the region of the local maximum) or decrease (for the region of the local minimum) the brightness of pixels and b) taking into account the number pixels that break the monotony of the segment brightness change. Using these estimates, it is shown that the proposed algorithm provides segmentation of artificial and natural grayscale images with a monotonic change in the brightness of pixels in the areas of local extrema. These properties allow us to consider the developed algorithm as a basis for the selection of texels, spots, low-contrast objects in images.

The analysis of scientific papers devoted to the mathematical description of electric generators of reciprocating motion with permanent magnets demonstrated that the proposed mathematical models of this type of generators are based on the theory of magnetic circuits. Such mathematical models are based on a simplified representation of the magnetic system and the magnetic field in the form of a magnetic circuit with corresponding magnetic conductivities. However, unlike traditional rotary type electric machines, electric generators of reciprocating motion have a number of features, the omission of which in mathematical modeling causes the increase of the cost of their creation (due to the duration of the design and experimental refinement of the generators). Therefore, at the initial stages of electromagnetic calculation and solving optimization problems, it is necessary to use adequate mathematical models to improve the accuracy of calculations of the parameters of these generators. For this purpose, a mathematical model based on field theory can be used; however, its main drawback is the complexity of its application for solving optimization problems. In this regard, to improve the accuracy of calculations of the parameters of electric generators of reciprocating motion with permanent magnets, it is proposed to use refining coefficients (coefficients of scattering and buckling of the magnetic flux) in mathematical models based on the theory of magnetic circuits. The authors have developed refined electromagnetic models of electric generators of reciprocating motion with permanent magnets, which make it possible to obtain the main parameters of generators at the initial stages of electromagnetic calculation and when solving optimization problems with acceptable accuracy. A distinctive feature of the refined electromagnetic models of generators is the consideration of the scattering and buckling coefficients of the magnetic flux in the magnetic system that change during the simulation.

Thermal power plants remain one of the main sources of environmental pollution. The deterioration of the quality of traditional carbon-containing energy resources leads to the need to develop technologies for co-combustion of biofuel and coal at small and large power plants. The paper proposes the concept of using solid waste from tire recycling by adding to the composition of the mixed fuel “coal – wood waste” as a substitute for coal slag, which is formed during the utilization of worn-out tires by pyrolysis. The aim of the work was to determine the possibility of increasing the calorific value of wood pellets by co-firing with pyrolysis slag instead of coal without increasing the burden on the environment. At the same time, the following tasks have been set: to determine the lowest combustion heat of mixed fuels and assess its change when replacing coal with slag; to determine moisture content, total sulfur content, volatile matter yield, ash content of mixed fuels according to standard methods; to assess the change in these parameters when replacing coal with slag at the same component ratios; to determine the optimal ratios of components in mixed fuels, which will not increase the burden on the environment when replacing coal with pyrolysis slag. It has been determined that replacing coal with slag results in an increase in calorific value by 37–45 %, a decrease in ash content by 37–42 %, and an increase in the yield of volatile substances. At the same time, the sulfur content increases by 5.6–18 %. The use of traditional cleaning equipment is recommended in order to reduce the emission of sulfur dioxide. The research results make it possible to substantiate the possibility of replacing coal with slag in mixed fuels at certain ratios of components. A new direction of using solid products from recycling of rubber products, i.e. worn-out tires, has been proposed by the pyrolysis method in mixed fuels “slag-wood pellets” for small and medium-sized power plants.

A meaningful characteristic of modern industrial production is given and prospects for the modernization of the Belarusian industry through new industrialization are identified in the paper. In this regard, the objectives of the study have been determined: to consider modern concepts of the transformation of economic systems under the influence of technological progress, to substantively characterize the new industrialization, including to describe the technological and organizational features of the new intentional production, to identify its distinctive features, to determine the prospects for using the concept of new industrialization for modernization of the Belarusian industry. The methodological basis was the general scientific methods and principles of сognition, namely: the method of deduction and induction, the method of comparative analysis, historical approach. The author considers the new industrialization as an economic structure that has developed as a result of the spread of digital technologies in a modern socially-oriented, predominantly market economy. The technological basis of the new industrial production is cyber-physical production systems that operate through the industrial Internet of things, the Internet of services and network mechanisms of interaction between all participants in the value added chain. The development of digital production and digital services entails the digitalization of business models. The result is flexible, adaptive, individualized industrial production through the triad of digital production, digital services and digital business models. When modernizing the Belarusian industrial complex, aimed at developing high-tech and knowledge-intensive industrial production and increasing the efficiency of traditional industries through the use of a wide variety of new technologies, the priority should be the comprehensive digitalization of production, services and business models.

International audience; The paper deals with the problem of identification of linearly varying frequency of sinusoidal signal with unknown amplitude and phase. Identification task for linearly varying frequency occurs, for example, during telescope operation control and it is of practical interest. Existing synthesis methods for identification algorithms of linearly varying frequency of sinusoidal signal use unlimited functions of time that is not attractive from a technical point of view, since the measurement noise multiplied by an unlimited function tends to give extremely poor estimates of the tunable parameter. This paper proposes a new approach for identification of linearly varying frequency comprising iterative filtering of measured sinusoidal signal (with the use of linear first order stable components), which in turn gives the possibility to obtain a simple linear regression model with one unknown constant parameter. We present computer simulation results, illustrating the performance of the proposed identification algorithm. Computer modeling was performed both in the presence and absence of the measurement noise. Also, comparative analysis of the proposed approach with the previously obtained methods was carried out within the framework of computer simulation. It was shown that the presented solution provides a significant improvement in the accuracy of an unknown frequency identification in the noise presence.; Рассмотрена задача идентификации линейно меняющейся частоты синусоидального сигнала, имеющего неизвестные амплитуду и фазу, возникающая, например, при управлении телескопом. Традиционно методы синтеза алгоритмов идентификации линейно меняющейся частоты синусоидального сигнала используют неограниченные функции времени, что вызывает технические проблемы, поскольку в этом случае наличие шумов при измерении может существенно исказить настраиваемый параметр. Предложен подход к идентификации линейно меняющейся частоты, предусматривающий итеративную фильтрацию (с использованием линейных устойчивых звеньев первого порядка) измеряемого синусоидального сигнала, которая позволяет получить простую линейную регрессионную модель с одним неизвестным постоянным параметром. Приведены результаты компьютерного моделирования, иллюстрирующие работоспособность представленного алгоритма идентификации. Компьютерное моделирование выполнено как при наличии шумов в измерениях, так и в их отсутствие. Путем компьютерного моделирования проведен сравнительный анализ предлагаемого подхода с полученными ранее методами, и показано, что представленное решение обеспечивает существенное повышение точности идентификации неизвестной частоты при наличии шумов

In this paper, the spectral dependences of the transverse Kerr effect (ТКЕ) are studied experimentally and theoretically. The results are obtained for deposited and annealed samples with a corresponding variation in the size of the granules. It was found that thermomagnetic annealing leads to an increase in the ТКЕ value in magnetic nanostructures, while the most noticeable changes in the effect value were observed in the range of medium and high concentrations of the magnetic component in the visible region of the spectrum. The expediency of using the effective medium approach for calculating magneto-optical effects in granular systems, taking into account the size distribution of granules within the lognormal distribution of granules, is shown. Based on this approach, the main features of the optical and magneto-optical properties of nanocomposites are explained by the example of (Co45Fe45Zr10)X(Al2O3)1–X. All calculations are performed in the Bruggemann approximation, which effectively describes the properties of nanostructures in the region of average concentrations. Size effects are clearly manifested in nanocomposites and have a significant impact on the optical and magneto-optical properties of nanocomposites, especially in the IR region of the spectrum, which is associated with intraband transitions. Taking into account the particle size distribution makes it possible to significantly improve the description of such promising inhomogeneous nanostructures. The solved problem is very important and relevant both from the fundamental point of view – the study of magneto-optical, optical and transport phenomena in nanocomposites – and from the point of view of the great possibilities of their application in modern electronics and nanoelectronics. Taking into account the size effects and the particle size dispersion makes it possible to find new promising functional materials and control their properties in a wide spectral range.

The paper presents an analytical review of the application of biometric recognition systems in relation to facial image identification technologies. The classification of biometric systems is presented. The trends of technological progress in the field of biometrics and facial recognition capabilities are considered. It is determined that in 2020 there is a trend of transition from the use of biometric recognition technologies in traditional state security systems to the sphere of commercial and user applications. The process of «linking» encryption keys and passwords with the biometric parameters of the data subject is described. It is proposed that a biometric feature and a biometrics parameter mean a certain value that has a physical meaning that characterizes the subject itself. The possibility of using circular neighborhood and bilinear interpolation of pixel intensity values in biometrics is also presented. This will make it possible to build a local binary template. In order to solve the problem of identification of persons, it is advisable to investigate the essence of biometric systems in the technologies of identification of persons, their types, identifying the shortcomings of each of them, on the basis of which to present the directions of elimination and search for the most reliable technologies. The essence of the use of biometric systems in the technologies of identification of persons is, for example, that the user can provide the bank or other counterparty with evidence that it is he who wants to use the services on his accounts. At the same time, the demand has increased for contactless biometric solutions. These technologies are implemented in order to conduct additional biometric verification of users. This allows to minimize possible fraud or violation of the internal rules of the service, for example, the transfer of accounts of some registered users to others.

Preference is given to cable lines with cross-linked polyethylene insulation in electrical networks with a nominal voltage of 10 kV during reconstruction of existing and construction of new industrial enterprises. The standard service life of such cables is at least 30 years (subject to the conditions of storage, transportation, installation and operation), and the actual one is determined by the technical condition of the cable. The service life of a cable line depends on the state of its insulation, the aging of which occurs under the influence of several factors. Conventionally, all factors influencing one or another degree on the cable insulation resource can be divided into thermal, electromagnetic, climatic, mechanical and operational. The most significant reason for the insulation aging is high temperature, which accelerates the reaction of thermo-oxidative destruction, during which high-molecular polymer compounds decompose. In fact, cables are operated at temperatures below the long-term permissible values, and, therefore, the aging of the insulation is slower, and the actual service life will be longer than the standard. At present, condition of the insulation is monitored with the use of high voltage tests related to destructive testing methods. When designing and operating cable lines, it is necessary to estimate the duration of the actual service life under various operating conditions. In theory, there are several expressions for calculating the service life of a cable line when exposed to temperature, humidity, electric field and aggressive environments, but all of them are not applicable in practice due to the presence of a large number of coefficients whose values are unknown. The paper presents an analytical expression obtained for determining the service life of power electric cables, taking into account the aging of the insulation under the influence of temperature and electric field.

This paper is devoted to construction of reference walking trajectories for developing pedestrian navigation algorithms for smartphones. Such trajectories can be used both for verification of classical algorithms of navigation or for application of machine learning technics. Reconstruction of closed trajectories based on data from foot-mounted inertial measurement units (IMU) is investigated. The advantages of the approach are the use of inexpensive sensors and the simplicity of the presented method. We propose algorithms for reconstruction of smooth 2D pedestrian trajectories based on measurements from a single IMU as well as on combined measurements from two IMU’s. Introduced algorithms are based on application of modified Kalman filter with an assumption of IMU having zero velocity when foot contacts the ground. In case of two measurement units, it is additionally assumed that the positions of the sensors cannot differ significantly from each other. The algorithms were tested on trajectories lasting from 1 to 10 minutes, passing indoors on horizontal surfaces. Obtained results were compared with high precision trajectories acquired with GNSS RTK receivers. Additionally, the process of inter-device time synchronization is investigated and detailed description of the experiments and used equipment is given. The dataset used for verification of proposed algorithms is freely available at: http://gartseev.ru/projects/rtj2021.

Introduction. In all types of digital communication, error control coding techniques are used. Many digital communication standards, such as Wi-Fi and 5G, use low density parity check (LDPC) codes. These codes are popular because they provide building encoders and decoders with low computational complexity. This work objective is to increase the error correcting capability of the well-known bit-flipping decoder (BF) of LDPC-codes. For this purpose, a modification of the decoder is built, which enables to dynamically control one of its main parameters whose choice affects significantly the quality of decoding. Materials and Methods. The well-known bit-flipping decoder of binary LDPC-codes is considered. This decoder has several parameters that are not rigidly bound with the code parameters. The dependence of the decoding quality on the selection of the output parameters of the bit-flipping decoder was investigated through simulation modeling. It is shown that the decoding results in this case are significantly affected by the input parameter of the decoder — threshold T. A modification of the BF-decoder of binary LDPC-codes has been developed, in which it is proposed to set the threshold dynamically during the execution of the algorithm depending on the error rate. A comparative analysis of the error- correcting capability of decoders is carried out by the simulation modeling method. Results. A lemma on the maximum value of the decoder threshold T is formulated and proved. Upper bounds for the number of operations are found for the original and modified decoders. A simulation model that implements a digital noise-immune communication channel has been built. In the model, the initial data is encoded with a given LDPC-code, then it is made noisy by additive uniformly distributed errors, and thereafter, it is decoded in turn by the bit-flipping algorithm with different threshold T parameters, as well as by a modified decoder. Based on the input and output data, the correction capacity of the decoders used is estimated. Experiments have shown that the error-correcting capability of the modified decoder in the range of the real error rate is higher than that of the original decoder, regardless of the selection of its parameters. Discussion and Conclusions. The lemma, proved in the paper, sets the upper bound on the threshold value in the original decoder, which simplifies its adjustment. The developed modification of the decoder has a better error- correcting capability compared to the original decoder. Nevertheless, the complexity of the modification is slightly increased compared to the original algorithm. It has been pointed out that the decoding quality of a modified decoder develops with a decrease in the number of cycles in the Tanner graph and an increase in the length of the code.

The subject of the research is key criminal risks in robotics. The purpose of the article is to confirm or disprove the hypothesis that key criminal risks of using robots may be identified and classified. The author dares to describe the key aspects of the application of risk-based approach in the assessment of robotic activities, identify the key risks of using robots, give a criminological classification. The methodology includes a formal logical method, systematic approach, formal legal interpretation of legal acts and academic literature, SWOT analysis. The main results of the study. The author applies the main provisions of criminal riskology when assessing encroachments involving robots. Key risks and challenges when using robots are identified. The severity of the consequences of harm caused by using robots (from minor to critical risk) is assessed and a matrix of the probability of its occurrence is provided. The author's criminological classification of robots is based on the risk-based approach and is substantiated on two grounds. The first one is the category of public danger and the second is the potential severity of the consequences of harm caused by robots. The causal complex that can lead to criminal risks in robotics is identified. The grounds of such risks are divided into those related to the mechanical subsystem of robots, digital subsystem of robots and power supply subsystem of robots. Conclusions. The risk-based approach is the most progressive and effective basis for regulating the criminal relations in robotics. The author demonstrates the existence of real risks to the peace and security of mankind, life and health of people, objects of wildlife, nonliving material objects from the use of robots. It is necessary to recognize robotics as source of increased potential criminal danger and to adopt appropriate regulation as soon as possible. The necessity and expediency of applying a risk-based approach to robotics is theoretically substantiated, and the characteristics of robots that are important in assessing the criminal potential of their exploitation are evaluated. The conclusions and recom mendations of this paper may become a basis for the implementation of the risk-based approach in legal regulation of robotics. The risk matrix presented in the article can be used to establish a framework for regulatory impact on robotics, assess the consequences of potential harm and minimize it.

The paper presents a thermodynamic analysis of secondary overheating in turbo-expander plants on low-boiling working fluids. The possibility of optimizing the parameters of the working fluid in a secondary stem superheater has been studied. The research was carried out for two typical turbo-expander cycles: with a heat exchanger at the outlet of the turbo-expander, intended for cooling an overheated low-boiling working fluid, and without a heat exchanger. Cycles inT–scoordinates were constructed for the studied schemes. The influence of pressure and temperature in the intermediate superheater on the exergetic efficiency of the turbo-expander unit was studied. Thus, the dependences of the exergetic efficiency and losses on the elements of the turbo-expander cycle are obtained when the temperature of the working fluid changes and pressure of the working fluid not changes in the intermediate superheater, and when the pressure changes and the temperature does not change. As a low-boiling working fluid, the ozone-safe freon R236EA is considered, which has a “dry” saturation line characteristic, zero ozone layer destruction potential, and a global warming potential equal to 1370. It has been determined that increasing the parameters of the low-boiling working fluid in front of the low-pressure turbo expander (regardless of the scheme of the turbo expander cycle) does not always cause an increase in the exergetic efficiency. Thus, overheating of the working fluid at a pressure exceeding the critical pressure causes a positive exergetic effect, but for each temperature there is an optimal pressure at which the efficiency will be maximum. At a pressure below the critical pressure, overheating leads to a decrease in the exergetic efficiency, and the maximum exergetic effect is achieved in the absence of a secondary steam superheater. All other things being equal, a turbo-expander cycle with a heat exchanger is more efficient than without it over the entire temperature range and pressure of the low-boiling working fluid under study.

Introduction. This paper analyzes the problem of formation of educational Internet resources. Despite numerous works concerning the importance of using information technologies in the education, the issue of its rational organization remains understudied. The purpose of the article is to analyze what patterns are observed when students read educational information from the screen, and how these patterns can be used to create educational Internet resources. Materials and Methods. To study the interaction of students with educational information on the screen, the authors used the method of oculography. The results were processed using the BeGaze and IBM SPSS Statistics 22 programs. In total 100 respondents participated in the experiment, 50 of which were trained in the natural sciences, 50 – in the humanities. Results. It is determined that the presence of media text influences the oculomotor activity of students: students commit fewer fixations and saccades, the average duration of saccades increases, the value of the Scanpath Length indicator decreases. It was revealed that the orientation of training forms strategies for working with information on the screen: students of natural sciences read texts longer, blink less often; they have a higher Scanpath Length value. When forming educational Internet resources, the developer should take into account the students’ specialisms with reference to e-material. It should also be borne in mind that the presence of images on educational Internet pages is perceived by students as a simplifying factor for completing the cognitive task of reading, but students practically do not pay attention to the images themselves. This may be attributed to the specificity of the learning process, when their main focus is on written texts acquisition. Discussion and Conclusion. The results of the study open a new direction in the study of the problem of rational organization of the student's learning process using technical devices and may be of interest to developers of educational Internet resources, as well as practicing teachers.

The article investigates the issues of psychological difficulties prevention in the medical profession in the training of medical students. The paper substantiates the arguments for strengthening the personal aspect of medical students’ training based on understanding the ideas about difficulties in the work of a doctor. The authors reveal the interrelation between personal characteristics of students (conscientiousness, understanding of emotions, benevolence, etc.) and their ideas about the nature of difficulties in the chosen specialty at the stage of training. The study presents the main directions of students’ understanding of such difficulties. The article describes strategies for supporting students based on the correlations of personal characteristics and the above-mentioned ideas, aimed at mastering a confident behavior by students. The proposed strategies can be of interest to teachers of courses related to ethical issues of the profession, as well as in individual work with medical students.

A large class of systems that have found application in various industries and households, electrified transportation facilities and energy sector has been classified as electrical engineering systems. Their characteristic feature is a combination of continuous and discontinuous modes of operation, which is reflected in the appearance of a relatively new term “hybrid systems”. A wide class of hybrid systems is pulsed DC converters operating in a pulse width modulation, which are non-linear systems with variable structure. Using various methods for linearization it is possible to obtain linear mathematical models that rather accurately simulate behavior of such systems. However, the presence in the mathematical models of exponential nonlinearities creates considerable difficulties in the implementation of digital hardware. The solution can be found while using an approximation of exponential functions by polynomials of the first order, that, however, violates the rigor accordance of the analytical model with characteristics of a real object. There are two practical approaches to synthesize algorithms for control of hybrid systems. The first approach is based on the representation of the whole system by a discrete model which is described by difference equations that makes it possible to synthesize discrete algorithms. The second approach is based on description of the system by differential equations. The equations describe synthesis of continuous algorithms and their further implementation in a digital computer included in the control loop system. The paper considers modeling of a hybrid electrical engineering system using differential equations. Neglecting the pulse duration, it has been proposed to describe behavior of vector components in phase coordinates of the hybrid system by stochastic differential equations containing generally non-linear differentiable random functions. A stochastic vector-matrix equation describing dynamics of the processes has been obtained in the paper. The equation contains both continuous and discrete components, which characterize an amplitude signal modulation. An equation for probability density of phase coordinate distribution in the system has been developed on the basis of a mathematical model for a hybrid system.

In this paper, we suggest to use hybrid approach to time series forecasting problem. In first part of paper, we create a literature review of time series forecasting methods based on hybrid neural networks and neuro-fuzzy approaches. Hybrid neural networks especially effective for specific types of applications such as forecasting or classification problem, in contrast to traditional monolithic neural networks. These classes of problems include problems with different characteristics in different modules. The main part of paper create a detailed overview of hybrid networks benefits, its architectures and performance under traditional neural networks. Hybrid neural networks models for time series forecasting are discussed in the paper. Experiments with modular neural networks are given.

Biomechanics of motor actions solves the problems of analysis of external motor events - kinematic and dynamic movement parameters. Inertial measurement devices such as gyroscope and accelerometer are used for biomechanical analysis of human movements. The paper describes an algorithm for analysis of kinematic characteristics of the running based on inertial gyro signals. Running is used to estimate the physical performance, endurance, coordination abilities of a person. Gyroscope signals were registered using the TrignoTM Wireless System. For data analysis in the MATLAB, the software for automated evaluation of electromyographic and biomechanical motion patterns was developed. The algorithm allows one to calculate time, spatial and spatial-to-time parameters of motion, symmetry of movements of the left and right limbs, and also stability of repetition of biomechanical movement pattern. The algorithm includes the following stages: 1) adaptive filtering of signals; 2) identification of movement phases; 3) calculation of spatial and time symmetry of left and right limbs; 4) analysis of the repetition stability of biomechanical movement pattern. The proposed algorithm was used to estimate the motor coordination potential of high-skilled athletes in longdistance running. The research made it possible to estimate individual features of work of each group of muscles for each sportsman while performing a test task with stepwisely increasing load on a running track. This approach is a tool to detect asymmetric work of paired muscle groups and of muscle groups with irrational workability. The proposed algorithm for the analysis of running kinematic characteristics can be used to develop new criteria for evaluating the effectiveness of solving a movement problem, as well as to assess the correctness of the movement technique and identify errors that can lead to injuries.

The paper addresses the problem of assessing the quality of fingerprint images using spatial analysis methods. The author proposes using the previously developed mathematical model to describe the set of magnitudes of the image gradient. The model is based on the two-parameter Weibull distribution. The author proposes two approaches to assess the quality of fingerprints. The first approach is implemented by the so-called “Full reference method”, which compares the Weibull distribution parameters’ values of statistical estimates. The results of identifying sweat pores using this method are presented. The second approach is called the “No-Reference method” and is used to assess fingerprints’ quality when analyzing and identifying the information content of their individual sections. It is proposed to use an image blur map as a quality characteristic and a statistical estimate of the Weibull distribution shape parameter as a measure of the blur. The shape parameter is estimated at each image point by the combination of magnitudes of the image gradient in the vicinity of the point; in this, the previously developed blur mapping technique is applied. The specific examples illustrate effectiveness of the proposed approaches.

The paper gives an analysis of perspectives for development of wind power generation, information on the share of wind energy in electricity generation in the world and in Russian Federation is provided as well. Data on gross, technical, economic potential of wind energy of Russia and the Murmansk Region has been presented. When calculating the gross wind energy potential of the region, data from the last 10 years of observations carried out at 37 meteorological stations have been used. The territory of the region has been divided into 6 distinctive zones, based on the wind activity. Gross energy potential has been calculated for each zone: for the heights of 10, 50, 100, and 150 m. Gross wind energy potential of the region at the height of 150 m has thus been estimated at 23,090 billion kWh. The Murmansk Region's 201 MW Kola wind farm, which consists of 57 Siemens Gamesa SG 3.4-132 wind turbines with a unit capacity of 3.465 MW, is to be constructed by 2021 under the direction of Enel Green Power. Wind energy potential and annual power generation of the Kola wind farm have been assessed. The difference between the obtained results and calculations of Enel Group's specialists amounts to less than 15 %. For the cases of relocation of Kola wind farm to different wind zones, the annual power generation of the wind farm has been estimated. It has been determined, that in case of Kola wind farm's relocation to the zone with the highest wind activity its annual electricity generation could be increased up to 1.5 times. A model of the Kola energy system has been developed in NEPLAN software, its validity has been proven. The calculations of the wind farm's operation modes show that voltage levels of the system nodes and powerflows are within the boundaries defined by normative documents. The effectiveness of reactive power regulation of the wind farm has been shown.