# 1 2024

Intelligent information systems

• M. R. Bogdanov, G. R. Shakhmametova, N. N. Oskin, A. V. Kornilov
  Biometric identification based on gait
• Abstract
  • Statement of the problem: the growth of extremism in many countries of the world makes the problem of contactless biometric identification urgent. Solving of this problem is complicated by the fact that rioters use various means of camouflage. Under these conditions, biometric identification based on facial recognition becomes ineffective. In this regard, gait recognition has a number of advantages, because gait can be recognized over a long distance, is difficult to fake, and changes slowly over time. To recognize gait, you can use various data sources, for example, a video stream, sounds of steps, or readings from inertial sensors of mobile phones located in the pockets of subjects. The purpose of the work is to study the factors influencing the effectiveness of biometric identification by gait when the video stream is the data source. Methods used: a video stream is used as a data source. Key points of the human body were extracted from the video stream using the MoveNet (Lightning and Thunder), PoseNet and BlazePose (Lite and Heavy) neural networks. Feature classification was carried out using a random forest and a fully connected neural network. Novelty: for biometric identification by gait, methods used to solve the problem of pose estimation were used. The influence on the efficiency of gait recognition of factors such as video resolution, frame rate, algorithm for extracting features from the video stream, and recording duration was studied. Result: It was found that: changing the frame rate and video resolution has a greater effect when using models that focus on high speed at the expense of accuracy: MoveNet in the Lightning version and BlazePose in the Lite version, the best result is achieved at a frame rate of 60 FPS, the worst at 24 FPS, increasing the frame rate to 120 FPS does not improve the result compared to 60 FPS, the video stream resolution of 1920 by 080 allows you to get better results compared to 3840?2160. Ensemble methods (random forest and gradient boosting) showed higher classification efficiency compared to a fully connected neural network. Practical significance: software was developed for biometric identification by gait. It can be used in security systems for biometric identification and identifying patterns of aggressive behavior.
• Key words
  • contactless biometric identification, machine learning, information security
• Reference
  • Bogdanov M. R., Shakhmametova G. R., Oskin N. N., Kornilov A. V. Biometric identification based on gait. Systems of Control, Communication and Security, 2024, no. 1, pp. 191-212. DOI: 10.24412/2410-9916-2024-1-191-212 (in Russian).

• R. S. Sherstobitov
  The model of information exchange masking in the departmental communication network
• Abstract
  • Problem statement: the need to transmit all types of information between departmental divisions is provided by a universal transportation network. In this regard, the threats of network reconnaissance and computer attacks on departmental data transmission networks are still relevant. One of the ways to prevent these threats is masking of address information and realization of masking exchange of network devices. However, the application of these measures reduces the availability of network nodes for the implementation of constructive information exchange, because false elements and masking traffic utilizes in conjunction with the constructive indivisible resource of communication channels and information processing network devices, and the transport layer protocols used have restrictions that do not guarantee continuous data transmission. The purpose of the work is to model development and study the functioning of the data transmission network of departmental purpose in the realization of information exchange masking in the conditions of network reconnaissance. Methods used: in the work the methods of research of random processes are used. The scientific novelty of the model lies in the application of mathematical apparatus of the theory of homogeneous semi-Markov processes with discrete states and continuous time to determine the probabilistic and temporal characteristics of the process of functioning of departmental data networks in the implementation of information exchange masking in the conditions of network reconnaissance. Practical significance of the model is to identify the probabilistic-temporal characteristics of the process of functioning of data transmission networks of departmental purpose in the conditions of network reconnaissance, necessary for determining the optimal values of the parameters of network connections of network nodes in the realization of information exchange masking in data transmission networks of departmental purpose. Result: the model of information exchange masking in the departmental communication network, which is formalized in the form of a semi-Markov random process with discrete states and continuous time. The obtained output probabilistic-temporal characteristics are used as target functions in the formulation of the vector optimization problem and optimal values of network connection parameters of nodes of the data transmission network of departmental purpose in the implementation of information exchange masking in the conditions of network reconnaissance.
• Key words
  • structural and functional characteristics, masking exchange, network connections, continuity of information exchange, random process, availability and security of network devices
• Reference
  • Sherstobitov R. S. The model of information exchange masking in the departmental communication network. Systems of Control, Communication and Security, 2024, no. 1, pp. 1-25. DOI: 10.24412/2410-9916-2024-1-001-025 (in Russian).

• A. B. Tokarev, V. A. Kozmin, A. P. Pavlyuk, V. Yu. Polev
  Duration of data collection when measuring occupancy of stationary radio channels
• Abstract
  • Purpose. Effective management of any resource is based on high-precision control of the use of this resource. In relation to radio spectrum management, this implies, in particular, the ability to accurately and reliably measure the occupancy of radio channels and frequency bands. The standardization of relevant measurements is regulated at the international level by documentation of the Radiocommunication Sector of the International Telecommunication Union (ITU-R). However, the analysis of this documentation shows that both in the current version of Recommendation ITU-R SM.1880-2 "Spectrum occupancy measurement and evaluation" and in the ITU Handbook on Spectrum Monitoring, the proposed solutions do not provide answers to some questions that arise when organizing occupancy measurements. The purpose of the present paper is to clarify the differences between occupancy measurement modes, which in regulatory documents are traditionally called measurements based on “independent samples” and “dependent samples”, as well as to search for calculation relationships that allow, under different conditions, to reasonably determine the duration of data collection sufficient to ensure accurate and reliable measurement of occupancy. Methods. The development of recommendations for determining a sufficient duration of data collection is based on classical methods of statistical analysis, and in relation to occupancy measurements based on "dependent samples" on the representation of a sequence of sample values by a first-order Markov chain. Novelty. The novelty elements of the presented solution are the study of the dependence of the required number of samples accumulated for a reliable assessment of occupancy on the relationship between the mean value of transmission duration in the analyzed radio channel and the interval for testing the state of this channel by radio monitoring equipment. Results. The developed calculation relationships make it possible to determine the required duration of data collection for almost any combination of transmission durations in the analyzed channel and channel state testing intervals. The correctness of the calculation relationships is confirmed by the coincidence of the values obtained by them with the required number of data samples in the classic work of Spaulding A.D. & Hagn G.H. "On the definition and estimation of Spectrum Occupancy" (1977). The revealed derivations are supposed to be used as an addition to the current versions of Recommendation ITU-R SM.1880-2 and the ITU Handbook on Spectrum Monitoring. Practical relevance. Obtained derivations eliminate a number of contradictions that arise when measuring occupancy based on existing ITU regulatory and methodological documents and the proposed calculation relationships allow controlling the procedure for measuring the occupancy of radio channels, taking into account the speed obtained by radio monitoring equipment.
• Key words
  • spectrum occupancy, occupancy evaluation, data collection, dependent samples, integration time
• Reference
  • Tokarev A. B., Kozmin V. A., Pavlyuk A. P., Polev V. Yu. Duration of data collection when measuring occupancy of stationary radio channels. Systems of Control, Communication and Security, 2024, no. 1, pp. 43-58. DOI: 10.24412/2410-9916-2024-1-043-058 (in Russian).

• S. I. Makarenko, R. L. Mikhailov
  Descriptive Model of WGS Satellite Communications System
• Abstract
  • Relevance. Providing communication services for military units which protect the interests of Russia beyond its borders requires the creation of special-purpose satellite communication systems (SATCOMM) with a global coverage area. Currently such projects are being developed in Russia. Simultaneously the technical decision making of geostationary SATCOMM requires the source data for modeling various ways of building the communication services. Another technologically advanced SATCOMM - Wideband Global Satellite Communications (WGS), which provides broadband operational, tactical and strategic link of the US armed forces, can be used for form that kind of the source data and may be a prototype of a special–purpose SATCOMM. The aim of the paper is to form a descriptive model of WGS. The descriptive model will be used for development of the source data for create of the new SATCOMM of Russian. Results and their novelty. The element of practical novelty of the paper is the revealed general technological features of special-purpose SATCOMM by the example of WGS. In particular, general principles of formation of orbital grouping satellites with next generation satellites, organization channel in "up" and "down" lines, using of signal-code structures in channels are described. Practical significance. Presented descriptive model will be useful for technical specialists to substantiate new technological solutions for domestic special-purpose SATCOMM. In addition, the model will be helpful for scientists who conduct research in the field of satellite communications.
• Key words
  • model, descriptive model, satellite communication system, SATCOMM, mobile satellite communication system, Wideband Global Satellite Communications, WGS
• Reference
  • Makarenko S. I., Mikhailov R. L. Descriptive Model of WGS Satellite Communications System. Systems of Control, Communication and Security, 2024, no. 1, pp. 59-94. DOI: 10.24412/2410-9916-2024-1-059-094 (in Russian).

• I. E. Afonin, S. I. Makarenko, R. L. Mikhailov
  Aerospace Attack Means by Leading Foreign Countries. Part 1. Intercontinental Ballistic Missiles
• Abstract
  • Relevance. The increase in geopolitical tensions observed since the start of 2022 has increased the likelihood of military conflict. The use of aerospace attack means (ASAM), such as ballistic missiles, has become a hallmark of modern warfare. In some instances, a conventional conflict may escalate into a nuclear war, with intercontinental ballistic missiles (ICBMs) being used for both preventive and counter-nuclear missile strikes. This research aims of the work to create descriptive models of ASAM of leading foreign nations (LFN), in particular, the formation of a description of intercontinental ballistic missiles (ICBMs). The model is based solely on open-source information. The results and their novelty. The generalized tactical and technical characteristics of typical ICBMs LFN are an element of novelty of the work. Practical significance. The descriptive model, which is presented in the work, The results of this study will contribute to the existing body of knowledge regarding ICBMs, providing valuable insights into the complexities of these systems and their potential impact on global security. The descriptive model of ICBMs will be useful for specialized specialists to substantiate the requirements for the tactical and technical characteristics of promising aerospace defense systems and methods of their combat use to ensure the protection of the Russian Federation.
• Key words
  • means of aerospace attack, descriptive model, intercontinental ballistic missile, tactical and technical characteristics, warhead, combat unit
• Reference
  • Afonin I. E., Makarenko S. I., Mikhailov R. L. Aerospace Attack Means by Leading Foreign Countries. Part 1. Intercontinental Ballistic Missiles. Systems of Control, Communication and Security, 2024, no. 1, pp. 138-190. DOI: 10.24412/2410-9916-2024-1-138-190 (in Russian).

• S. Karri, R. S. Surovtsev, P. V. Mikola, I. A. Skornyakov
  Methodology for optimisation of strip devices based on coupled lines with modal decomposition
• Abstract
  • Purpose. Radioelectronic devices are widely used in various fields of science and technology. Trends in their development are aimed at increasing the operating frequencies, reducing the voltages of the signals used, and increasing the density of PCB tracing and element layout. This leads to lowering the threshold of their sensitivity to electromagnetic interference (EMI). One of the new approaches to protection against EMI is the use of stripline structures with modal decomposition. These structures enable EMI decomposition into components of smaller amplitudes. Designing such devices requires optimisation of cross-sectional parameters according to one or several criteria for which evolutionary methods of optimisation are used. The main criteria include impedance matching and minimisation of the voltage amplitude at the device output (amplitude criterion), which is achieved by equalising the amplitude of the decomposition components. Amplitude criterion convergence is determined by calculating the time response at the output, due to which the time cost of optimisation is high and needs to be reduced. It is noteworthy that the conditions of equality of response components at the output of strip devices can be obtained analytically. Their application as criteria of the target function will allow excluding the calculation of the time response from the optimisation process, thus reducing the time cost. Aim of this work is to develop criteria and create a methodology to optimise strip devices based on modal decomposition. Methods. To obtain the conditions, we used simple analytical approaches proposed to analyse the time response in coupled transmission lines. To calculate the linear parameters of strip devices and the time response, we used a quasi-static approach. To validate the methodology and estimate the acceleration, we used genetic algorithm, evolutionary strategies and particle swarm method. Novelty. The methodology novelty is determined by the use of conditions for amplitude equality. These conditions are obtained in numerical and analytical forms as optimisation criteria and exclude the procedure of calculating responses from the optimisation problem. Results. The developed methodology of parametric optimisation of stripline devices with modal decomposition differs in that it applies the conditions of equality of normalised amplitudes of response components at the device output. It is shown that when using the proposed conditions as criteria, the average optimisation acceleration reaches 185.8 times and does not depend on the choice of the optimisation method. The highest acceleration is observed for two-wire devices, and the smallest - for three-wire modal filters. This may be caused by the increase in the cost of calculating the matrices of the linear parameters of the devices due to the increase in the number of their conductors. In addition, it was revealed that the relationship between the acceleration and the number of calculations and time samples on the excitation edge when calculating the time response has the linear character. Comparison of the voltage waveforms at the output of strip devices, which were obtained during optimisation using different target functions, proved the applicability of the conditions as criteria.
• Key words
  • electromagnetic compatibility, interference, protection, modal signal distortion, strip devices, optimisation, evolutionary methods, acceleration
• Reference
  • Karri S., Surovtsev R. S., Mikola P. V., Skornyakov I. A. Methodology for optimisation of strip devices based on coupled lines with modal decomposition. Systems of Control, Communication and Security, 2024, no. 1, pp. 95-117. DOI: 10.24412/2410-9916-2024-1-095-117 (in Russian).

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• G. Y. Kim, A. V. Nosov
  Decomposition of the ultrashort pulse in a meander microstrip line of two turns
• Abstract
  • Problem statement: with the development of electronic equipment (REE), its performance increases, operating voltages decrease and the routing density of printed circuit boards increases, which increases the susceptibility of REE to various electromagnetic influences. It is known that electromagnetic waves can pose a threat to modern electronic equipment. Thus, generators of powerful electromagnetic waves can be used by attackers to destabilize or completely disable critical infrastructure. An ultrashort pulse (USP) poses a serious threat to REE. There are many traditional methods of protection against USP, but they have disadvantages: low power and speed, limited response life, and also low radiation resistance due to the semiconductor components in their composition. This is unacceptable, for example, for the space industry, due to the need to increase the active life of spacecraft to 15 years. In this regard, it is necessary to search for new approaches to the protection of REE that are free of such shortcomings. One of the promising approaches to protecting REE is an approach based on the attenuation of USP in a meander microstrip line (MSL) of two or more turns. However, the practical implementation of such structures in modern REE is difficult due to the large lengths of the structures and/or the dielectric permittivity of the substrate. Therefore, their improvement is necessary. First, it is advisable to consider a simpler structure (of two turns) using a radio-absorbing material (RAM) and folding the turns. Purpose: improvement of meander MPL of two turns due to their folding and coating with RPM. Methods: analysis, structural-parametric optimization by heuristic search, as well as computational (based on various numerical methods) and natural experiments. Novelty: to further weaken the USP, enable practical implementation, and reduce the dimensions of the device, the rolling of each turn of the line into minor turns and a radio-absorbing material (RAM) as a covering layer were used for the first time. In addition, for the first time, the conditions for the decomposition of the USP in a meander MSL consisting of two folded turns coated RPM have been formulated. Results: it was revealed that the arrival sequences of decomposed pulses in structures with and without RPM are different. In this regard, new conditions for the decomposition of the USP are formulated. It was revealed that the folding of each turn of the meander MSL into non-core turns leads to an additional attenuation of the USP. A prototype of a meander MSL was made from two turns of reduced dimensions. The measured attenuation of the USP in it was 5.8 times (15.3 dB). The width and length of the layout were 46 and 57 mm, respectively, while without RPM and folding each turn into non-main turns they were 10 and 575 mm, respectively. Analysis of N-norms of the structure showed that N1, N2, N3 and N5 decreased by 5.75, 13.16, 1.04 and 2.92 times, respectively, and N4 increased by 1.54 times. Practical relevance: the solution can be used in critical REE for protection against USP, for example, for data transmission in various low-speed interfaces, as well as in power circuits with voltages up to 530 V and currents up to 850 mA.
• Key words
  • ultrashort pulse, meander line, even mode, odd mode, electromagnetic compatibility, protection
• Reference
  • Kim G. Y., Nosov A. V. Decomposition of the ultrashort pulse in a meander microstrip line of two turns. Systems of Control, Communication and Security, 2024, no. 1, pp. 118-137. DOI: 10.24412/2410-9916-2024-1-118-137 (in Russian).

• S. V. Masteevich, A. V. Timoshenko, A. Y. Perlov, V. A. Pankratov
  Algorithm for Increasing the Accuracy of Predicting Failures of Radar Equipment Based on Controlling the Polling Frequency of Technical Condition Monitoring Sensors
• Abstract
  • Purpose. Сontainerized radar stations in power-stressed modes experience significant heating of the equipment due to their dense layout and high signal power. The most numerous and non redundant component of the equipment is the power amplification unit, which experiences the greatest heat. Temperature monitoring with the help of sensors is carried out with a constant frequency of data acquisition, however, the resulting array of temperatures used as a training sample in forecasting does not allow to obtain a forecast of high accuracy. This may lead to premature failure of the units and decrease the functional characteristics of the station. The purpose of the work is to create an algorithm to improve the accuracy of prediction of failure of radar equipment on the basis of controlling the frequency of polling temperature sensors. It is proposed to use metrological methods to substantiate the algorithm for determining the frequency of data acquisition depending on the temperature of the equipment. Result. The algorithm analyzes the data of the control and diagnostic system and on the basis of the tolerance criteria sets the optimal frequency of interrogation of control sensors, on the one hand increasing the completeness of the data of the training sample model prediction of the technical state of the radio-electronic complex, and on the other hand - preventing overtraining the model with redundant data. Practical relevance. The developed algorithm can be used in the realization of the strategy of proactive maintenance of radar monitoring with the use of forecast data, significantly reducing the time of technical maintenance and costs for its implementation. Based on the refined forecast data, a decision can be made to control the cooling system.
• Key words
  • proactive control, radio-electronic complex, machine learning, technical condition forecasting, polling frequency, control sensor
• Reference
  • Masteevich S. V., Timoshenko A. V., Perlov A. Y., Pankratov V. A. Algorithm for Increasing the Accuracy of Predicting Failures of Radar Equipment Based on Controlling the Polling Frequency of Technical Condition Monitoring Sensors. Systems of Control, Communication and Security, 2024, no. 1, pp. 26-42. DOI: 10.24412/2410-9916-2024-1-026-042 (in Russian).