# 4 2023
Information security

Structuralparametric method of protection of information and telecommunication network of special purpose in the conditions of information conflict
 Abstract
 Purpose. Increasing the security of the special purpose information and telecommunication network (SP ITN) in the conditions of information conflict by operational management of structural and functional parameters of the elements. Methods. The solution of the problem is based on the joint application of methods of conflict theory, system analysis theory, set theory, control theory, optimization theory, modeling theory and combinatorics. Novelty. The proposed method is the development of the theory of management methods of SP ITN, the novelty elements of the presented solution consist in the use of additional source data, taking into account the data of forecasting the dynamics of their changes in the process of conflict development, which increases the accuracy of the assessment of time and probabilistic parameters of security when forming a model of changes in the security indicators of elements of SP ITN, as well as taking into account the impact of the selected actions when making decisions on changing the structural and functional parameters of elements during the information confrontation. Results. The use of the proposed method makes it possible to increase the efficiency and validity of responding to changes in the situation when managing the security of SP ITN by monitoring and predicting the current values of time and probabilistic indicators, as well as the process of developing scientifically sound solutions for managing the structural and functional parameters of the elements of SP ITN. Based on the results of the modeling of the method, its adequacy and extended functionality were confirmed. Practical relevance. The presented applied results can be implemented in the form of special software for information and analytical complexes in decision support systems for the protection of SP ITN. In addition, the proposed method can be used in the creation of intelligent control systems of a new generation, not only SP ITN, but also in the proactive management of other technical systems operating in conditions of information conflict.
 Key words
 information and telecommunication network, security, management, conflict, algorithm, dynamics of change, monitoring and intelligence system, resource management
 Reference
 Lipatnikov V. A., Parfirov V. A. Structuralparametric method of protection of information and telecommunication network of special purpose in the conditions of information conflict. Systems of Control, Communication and Security, 2023, no. 4, pp. 105156. DOI: 10.24412/2410991620234105156 (in Russian).

Methodology for assessing the functional stability of a heterogeneous system for detecting, preventing and eliminating the consequences of computer attacks
 Abstract
 Purpose. The modern conditions of information conflict, the structural elements of a heterogeneous system for detecting, preventing and eliminating the consequences of computer attacks operate under conditions of destructive intentional and unintentional influences aimed at disrupting their functioning and availability and, as a consequence, transferring them to an unstable state in which they do not provide effective solutions to the tasks assigned to them. One of the key activities aimed at countering or eliminating the consequences of existing destructive influences is the rapid assessment of the current level of functional stability of the object in question. Analysis of practical and theoretical aspects in a given subject area indicates the absence of complex technical solutions capable of ensuring automation of the process under study, and the existing scientific and methodological solutions do not take into account the design features and dynamics of functioning of a given assessment object in its various modes and are generally not applicable in the selected conditions its operation. The aim of the work is to form a unified structured approach to increasing the efficiency of assessing the functional stability of the functioning of a heterogeneous system for detecting, preventing and eliminating the consequences of computer attacks in the normal, enhanced and combat mode of its operation under destructive influences aimed at disrupting the functioning process and the availability of its structural elements, taking into account features of its construction as a systemdynamic model, through the development of appropriate scientific and methodological apparatus. Methods used. Solving the problem of assessing the functional stability of the functioning of the object under consideration in selected modes and conditions, taking into account the peculiarities of its construction and dynamics of functioning, is based on the use of the principles of systems theory and system analysis, the methodology of systemdynamic modeling and analytical methods (algebraic expressions and logical conditions). As a generalized indicator of the functional stability of the functioning of the object under consideration, based on the methods of Savage normalization and normalization by a given value, an additive convolution of the current values of partial indicators of effectiveness, resource intensity and efficiency of the process of functioning of a given object in selected operating conditions, calculated taking into account their relative importance and application of the concept ( criteria) suitability. The novelty of the work lies in the presentation of the object under consideration in the form of a systemdynamic model and in the development of a system of key indicators and analytical connections between them, allowing to obtain a quantitative assessment of the current level of functional stability of the functioning of a given object in selected conditions and modes, taking into account the peculiarities of its construction and functioning dynamics, as well as providing a scientific and technological basis for assessing its structural, informational and generally dynamic stability. Result. A targeted sequence of actions is described in detail to obtain a quantitative assessment of the current level of functional stability of the operation of the object in question in the selected conditions and modes, allowing the development of an appropriate software model that ensures automation and increased efficiency of the process under study, as well as the further validity of making and implementing a decision to manage a given object. Practical relevance. The proposed methodology can be used in the synthesis and practical implementation of a control system for the functioning of the object under consideration, capable of ensuring the required level of efficiency of the object being assessed in a certain mode of its functioning under destructive influences aimed at disrupting the functioning process and accessibility of its structural elements.
 Key words
 functional stability, methodology, system of detecting computer attacks, systemdynamic model, destructive influences, indicator, criterion
 Reference
 Konovalenko S. A. Methodology for assessing the functional stability of a heterogeneous system for detecting, preventing and eliminating the consequences of computer attacks. Systems of Control, Communication and Security, 2023, no. 4, pp. 157195. DOI: 10.24412/2410991620234157195 (in Russian).
Transmission, reception and processing of signals

Signal Modeling in Continuous Communictaion Channels in the Form of Stochastic Differential Equations
 Abstract
 Relevance. The development of mathematical models of signals in continuous communication channels is a necessary stage in the study of communication channels, since field testing, as a rule, is a complex and not always physically possible process and is limited and timeconsuming. Therefore, the creation of models is a necessary step in studying the characteristics of communication channels and developing algorithms for the primary processing of signals in them. One of the main requirements for such models is their adequacy to real processes occurring in the channel, which can be assessed by comparing the results of modeling random processes with theoretical probability distribution densities according to the agreement criteria. One of the most constructive modeling approaches is to use the state variable method and build models in the form of stochastic differential equations. At the same time, modeling signals in continuous communication channels in the form of stochastic differential equations involves solving the problem of synthesizing such equations, that is, determining their dimensions and coefficients with the required accuracy, which is the subject of this article. The problem of modeling coherent and partially coherent signals in the form of onedimensional and multidimensional stochastic differential equations is considered. Equations are synthesized for partially coherent signals in the spacetime sense and for partially coherent signals in the frequency domain. It is shown under what conditions a partial coherence of signals occurs and their characteristics are analyzed. To estimate partially coherent signals in the frequency domain, a modified Kalman filter is proposed. The purpose is the presentation of methods for the synthesis of stochastic differential equations that describe random signal parameters (transmission coefficient, amplitude, phase, number of requests waiting to be serviced in BRAN networks, etc.) in continuous communication channels, and the development of new onedimensional and multidimensional equations based on them for different distributions. The results, their novelty and practical significance. In this paper, new stochastic differential equations are synthesized and their adequacy for representing random signals in continuous communication channels according to the goodness of fit criteria is analyzed by comparison with theoretical distributions. It is shown that the models have good accuracy in representing the probabilistic characteristics of random processes. In this case, the equation for the Rice distribution makes it possible to model the amplitudes of signals in multipath channels, and the uniform distribution  the phases of the signals. The review of methods for the synthesis of stochastic differential equations given in the initial part of the work will be useful to specialists involved in the development and study of signal models in continuous communication channels.
 Key words
 stochastic differential equations, partially coherent signals, mathematical modeling, Rayleigh law, Doppler effect, probability distribution density
 Reference
 Glushankov E. I., Kontorovich V. Ya., Karavaev D. А. Signal Modeling in Continuous Communictaion Channels in the Form of Stochastic Differential Equations. Systems of Control, Communication and Security, 2023, no. 4, pp. 135. DOI: 10.24412/2410991620234135 (in Russian).

Simulation model of the receiver of the detection and warning system for laser irradiation of unmanned aerial vehicles
 Abstract
 Problem statement: The development and implementation of various means of countering unmanned aerial vehicles carrying out unauthorized actions in critical areas, including means that use laser radiation, necessitates the parallel development of onboard systems for detecting and warning of laser irradiation in order to increase the security of unmanned aerial vehicles. The effectiveness of laser radiation detection and warning systems is assessed based on the ability to ensure registration of laser radiation at the maximum possible distance from the source. The key element of a laser detection system is the laser receiver. The task of increasing the detection range of laser radiation by a receiver is a complex multifactorial task that can be solved by developing a comprehensive simulation model of the operation of the receiver to optimize its design parameters and operating modes, taking into account all the main external and internal factors that are interrelated and affect the detection range of laser radiation. The purpose of the work was to create a simulation model of a laser radiation receiver to optimize its design parameters through virtual modeling in order to increase the efficiency of detection and warning systems for laser irradiation of unmanned aerial vehicles. Methods: computer simulation methods using the MATLAB software package, including MATLAB Simulink, and atmospheric computer code LOWTRAN VII were used to solve the tasks. Novelty of the result lies in the creation of a universal multiparameter simulation model of the functioning of a laser radiation receiver, as well as a set of dependences of the detection range of a laser source identified by computer modeling on its basis on the main design parameters of the receiver, atmospheric conditions changing due to changes in the flight altitude of an unmanned aerial vehicle and weather conditions. conditions, parameters of the laser radiation source. Result: for the first time, a simulation model of the functioning of a laser radiation receiver has been created for detection and warning systems of laser irradiation of unmanned aerial vehicles, which allows, through virtual modeling, to optimize its design parameters at the development stage in order to ensure registration of laser radiation at the maximum possible distance from the source, to predict the functionality of the receiver depending on the changing operating conditions of unmanned aerial vehicles and the parameters of the laser radiation source. The simulation carried out using the developed model made it possible to identify factors that negatively affect the functionality of the receiver, to formulate requirements for the design of a laser radiation receiver, allowing for the registration of laser radiation by the receiver at the maximum possible distance from the source. Practical significance: the developed simulation model can be used as a developer tool when creating laser radiation receivers, as well as a basis for developing a software module for controlling the laser radiation detection process as part of the onboard equipment of a laser radiation detection and warning system during the operation of unmanned aerial vehicles.
 Key words
 simulation model, laser radiation, laser radiation source, unmanned aerial vehicle, receiver of the laser radiation detection system, threshold power, detection range, optical system, lens, focal length, photodiode, spectral sensitivity, atmosphere, transmittance, external and internal noise
 Reference
 Kurkova O. P. Simulation model of the receiver of the detection and warning system for laser irradiation of unmanned aerial vehicles. Systems of Control, Communication and Security, 2023, no. 4, pp. 3662. DOI: 10.24412/24109916202343662 (in Russian).

Methodology for estimating the bandwidth of a satellite communication channel with fading
 Abstract
 Problem statement: It is known that signal fading leads to a decrease in interference immunity and bandwidth of the communication channel. Existing methods for estimating the capacity of a satellite communication channel do not take into account the influence of ionospheric perturbations accompanied by the formation of smallscale inhomogeneities on the occurrence of fading of received signals. The purpose of the work: is to develop a methodology for assessing the impact of smallscale fluctuations in the total electron content (TEC) of the ionosphere and the choice of the carrier frequency on the capacity of the satellite communication channel. Result: a set of analytical expressions was obtained to estimate the dependence of the normalized bandwidth of the transionospheric communication channel on the signaltonoise ratio at the receiver input, the standard deviation of smallscale fluctuations of the ionospheric TPP and the carrier frequency of the signal. Novelty: the novelty of the developed methodology lies in the application of models of changes in the height of the electron concentration in smallscale ionospheric formation and the process of ionospheric fading during the propagation of radio waves in satellite communication systems as a basis for obtaining the dependence of the capacity of the satellite communication channel with fading on the standard deviation of smallscale fluctuations of the ionospheric TEC. Practical significance: the results obtained from the development of the methodology allow us to identify the main regularities of the influence of the increase in the carrier frequency of the satellite communication system, the signaltonoise ratio at the receiver input and smallscale fluctuations of the total electronic content of the ionosphere at its natural and artificial perturbations on the change in the capacity of the satellite communication channel.
 Key words
 capacity, bandwidth, probability of error, satellite link, fading, ionosphere, total electronic content, TEC, smallscale heterogeneities
 Reference
 Pashintsev V. P., Diptan P. A., Grinev E. M., Kiselev N. V. Methodology for estimating the bandwidth of a satellite communication channel with fading. Systems of Control, Communication and Security, 2023, no. 4, pp. 243266. DOI: 10.24412/2410991620234243266 (in Russian).
Electronic, radio and electrical systems

Overview of methods for modification of magnetic, shielding, radioabsorbing materials and coatings
 Abstract
 Purpose. A review in the field of methods of modification of the structure of materials possessing magnetic properties has been carried out. It is shown that the increase of efficiency of magnetic, shielding, as well as radioabsorbing materials and coatings is achieved by creating textured or gradient structures, for example, "ferritenonmagnetic conductor", which have a significant effect on wear resistance, electrical conductivity, as well as magnetic, scattering and absorbing properties. The aim of the paper is to analyse modern methods of modification of properties and characteristics of magnetic, shielding, and radioabsorbing materials and coatings. Methods. The paper considers methods related to electronbeam treatment, plasma treatment, thermal annealing, as well as laser treatment of materials possessing magnetic, shielding and radioabsorbing properties. Novelty. The combined application of the considered processing methods allows to organise the processing process for a wide profile of magnetic, shielding and radioabsorbing materials without limitation on the aggregate state of the initial raw material and temperature within the framework of the production process. Results. Using the presented methods of influence on the structure of magnetic, shielding and radioabsorbing materials it is possible to organise the process of production of improved materials at any stage within the technical process at minimum financial and time expenses. Practical relevance. Practical significance is caused by the opportunities for realisation of various modified magnetic, shielding and radioabsorbing materials. In particular, the use of the considered methods allows processing not only finished, monolithic structures with modified surface and nearsurface layers, but also initial powdered magnetic raw materials, to process the entire available volume of the substance, which has a more positive effect on the final characteristics of the product.
 Key words
 electronbeam treatment, plasma treatment, heat treatment, laser treatment, radioabsorbing materials, radioabsorbing coatings
 Reference
 Lakoza A. M. Overview of methods for modification of magnetic, shielding, radioabsorbing materials and coatings. Systems of Control, Communication and Security, 2023, no. 4, pp. 196218. DOI: 10.24412/2410991620234196218 (in Russian).

Optimization of a modal filter based on a microstrip line according to frequency criteria
 Abstract
 Purpose. In the last decade, the proper functioning of modern radioelectronic equipment has been complicated by a complex electromagnetic environment due to the influence of electromagnetic interference (EMI) of various natures. Ultrashort pulses (USPs) can act as EMIs, which are particularly dangerous due to their high voltage level and fast rise time. The response time of traditional protective devices is often insufficient. Therefore, other devices for protection against USPs, called modal filters (MFs), are being actively developed. When designing an MF, the developer has the need to select a set of optimal parameters for a specific application area. For this purpose, global optimization methods are effectively used, in particular, the genetic algorithm (GA), evolutionary strategies (ES) and the random search (RS) method. At the moment, a number of criteria have been formulated for optimizing MF in the time domain. At the same time, analysis of the frequency characteristics of the MF is no less important. For example, when taking into account the requirements for the bandwidth of the useful signal. Thus, realizing the possibility of optimizing MFs in the frequency domain when designing them for specific electrical circuits is an urgent task. Formulation and approbation of frequency criteria for maximizing and controlling useful signal bandwidth when optimizing MF based on a 3conductor microstrip line (MSL). Methods. Simulation and optimization were performed in the TALGAT quasistatic system based on the method of moments. Optimization was performed using a genetic algorithm (GA), a modified evolutionary strategies (ES) algorithm, and a random search (RS) algorithm. Optimization was accomplished separately according to two new frequency criteria: maximization and control of the useful signal bandwidth. Novelty. For the first time, two criteria were formulated and tested for optimizing any strip or cable structures in the frequency domain: maximization (to maximize the cutoff frequency MF) and control (to set the cutoff frequency to the required value) of the bandwidth. Results. For the first time, two new criteria were formulated and approved, suitable for optimizing any structures with modal phenomena in the frequency domain. These are criteria for maximizing and controlling the bandwidth of the useful signal. When optimizing within the range of specified parameters according to the first criterion, it was possible to increase the bandwidth of MF from 20.9 to 518.2 MHz when using ES, to 517 MHz (using GA) and to 505.8 MHz (using SP). When optimizing according to the second criterion, it was possible to obtain the required bandwidth level of 425 MHz for all algorithms. Taking into account a detailed assessment of the algorithms operation, the most preferable algorithm for optimization in the frequency domain is ES due to the best convergence rates and finding the global extremum of the objective function. The formulated criteria have been successfully approved in the optimization of MFs with real parameters and can be effectively used in their design. The results obtained have practical applications. Practical relevance. The formulated frequency optimization criteria make it possible to take into account the bandwidth level when designing protective devices operating on the principle of modal filtration. They are applicable to various types of MFs, regardless of the structure (strip or cable) and can be effectively used in design
 Key words
 electromagnetic compatibility, ultrashort pulse, optimization, evolutionary algorithms, bandwidth.
 Reference
 Belousov A. O., Gordeyeva V. O., Kim G. Yu. Optimization of a modal filter based on a microstrip line according to frequency criteria. Systems of Control, Communication and Security, 2023, no. 4, pp. 219242. DOI: 10.24412/2410991620234219242 (in Russian).

An improved algorithm for studying the safety of electronic circuits using Nnorms in electronic equipment
 Abstract
 Problem statement: As the number of electronic devices grows, it can become difficult for them to work together. The current trend towards miniaturization motivates developers of electronic equipment to design components so that there is a minimum distance between them. However, small distances produce serious coupling issue for the device operation. More specifically, when electronic components interact, there is a possibility of electromagnetic interference or crosstalk that can negatively affect the performance of critical elements. This issue is particularly relevant for sophisticated critical systems, for example, large data centers or aerospace equipment. The complexity of developing devices and taking into account their safety lies in the large time costs spent on the design process. In this regard, engineers can take advantage of simulation systems and reduce this time. Moreover, they can predict and simulate scenarios that may potentially produce dangerous effects, such as electrical breakdowns, interference or sparking of components, when several wires are located close to each other. However, it is still relevant to improve simulation systems with respect to their accuracy in identifying and preventing uncontrolled behavior of electronic equipment as early as at the design stage. The purpose of this work is to present a novel algorithm that features the search for voltage extremes and the use of Nnorms for identifying vulnerable places, i.e. with high peak voltages, as well as to compare the performance of this algorithm with the existing one in determining signal responses along all possible propagation paths in test and real structures.Methods: Within the framework of the study, we employ the search for extreme voltages, Nnorms, and quasistatic analysis of six multiconductor transmission lines. Novelty: A novel algorithm is introduced that determines all possible signal propagation paths of signal response using Nnorms on the example of real structures. A superior performance of this algorithm is proven by comparing it with the existing one. Result: The use of the novel algorithm enabled determining all possible paths in six structures, one of which is a real modal filter. As a result, a global maximum voltage found with the improved algorithm exceeded the voltage found by the existing algorithm by 15%, and a minimum voltage – by 110%. Practical relevance: Comparing the proposed algorithm using real structures allowed us to test the work of this algorithm more widely. Its further refinement will make it possible to more accurately analyze the safety of electronic devices of increased complexity. The proposed improvement of the algorithm was implemented in the domestic software TALGAT, which is vital for the technological sovereignty of our country.
 Key words
 electromagnetic compatibility; Nnorms; meander lines, maximum and minimum voltage.
 Reference
 Gazizov R. R. An improved algorithm for studying the safety of electronic circuits using Nnorms in electronic equipment. Systems of Control, Communication and Security, 2023, no. 4, pp. 267282. DOI: 10.24412/2410991620234267282 (in Russian).
Modeling of complex organizationaltechnical systems

Estimating of the Effectiveness of the Weapon System against of Small Unmanned Aerial Vehicles by Computer Simulation
 Abstract
 Purpose. The study is dedicated to the development of the computer model to estimate the effectiveness of a complex antidrone system (ADS). In this study the drone is a small unmanned aerial vehicle (UAV). The ADS detects, localizes and eliminates UAVs. It consists of radars and countermeasure devices which have different characteristics and configurations. The simulation model allows to bound the usefulness of engineering solutions in the first steps of system design. Also, the model affords of opportunity to compare those solutions with each other. Moreover, it is planned to use the ADS computer model to design more efficient systems and to solve optimization problems for different scenarios of challenges. Currently researches of such complex ADS are not found. Methods. The Monte–Carlo method is the basic modeling method. Statistics is accumulated during the simulation. It allows to calculate criteria of the ADS effectiveness. The criterions are the UAVs’ destruction probability, ammunition consumption, taskperformance time, the probability of incapacitation of the countermeasure system elements, etc. The discreteevent approach makes it possible to simulate longduration processes in the practically boundless space. Stochastic finite state machines present states of models of the ADS elements and transferences between these states. The UAV’s trajectory is presented by third order Bezier curve. This curve is widely used in studies of UAVs motion. The computer model takes into account the geometry of the UAV and the change in the orientation of it during the flight. Smooth interpolation of the rotation matrices of the associated coordinate system is carried out using spherical interpolation of quaternions. The fact of targets detection by the radar is established according to the Neyman–Pearson criterion. Novelty. The novelty is due to the possibility of modeling the ADS, consisting of several interconnected means of neutralizing and detecting targets. The model emphasizes the possibility of disabling the ADS’ elements. It is possible to figure out the effectiveness of the countermeasure system according to various criteria. Moreover, a new efficiency criterion has been formulated. It is the probability of destroyed UAVs falling into restricted (protected) zones. Such zones correspond, for example, to critically important infrastructure. The set of methods used in the developed simulation model and its software implementation are also new, namely, the discreteevent approach is applied in the context of objectoriented programming and agentbased modeling. This allows to model multifarious behavior of agents such as the agents of UAVs, radar and countermeasure subsystems. Results. The computer model allows, in a reasonable time and with limited computing power, to evaluate the effectiveness of various modifications of the ADS under different scenarios and target environment. Practical relevance. The simulation model can be employed and improved in the course of research and development work. It also can be applied at the initial stages of the ADS design for a more rigorous justification of technical solutions.
 Key words
 computer simulation, small UAV, drone, antidrone system, efficiency, detection, radar, neutralization, important infrastructure
 Reference
 Fedulov V. A., Bykov N. V. Baskakov V. D. Estimating of the Effectiveness of the Weapon System against of Small Unmanned Aerial Vehicles by Computer Simulation. Systems of Control, Communication and Security, 2023, no. 4, pp. 63104. DOI: 10.24412/241099162023463104 (in Russian).
Scientific contribution

Mikhail Alexandrovich Gavrilov and the logical theory of designing discrete control systems
 Abstract
 Relevance. The biography of a major scientist in field of automation and telemechanics, Mikhail Alexandrovich Gavrilov, dedicated to the 120th anniversary of his birth, is considered. The purpose of the article is to use the example of the scientific work of M.A. Gavrilov to form among beginning scientists an understanding of various approaches to the formation of new scientific knowledge. Result. To achieve the purpose of the article, domestic and foreign literature was used. The meaning of the scientific results of M.A. Gavrilov is outlined. Novelty and theoretical significance. The scientific biography of M.A. Gavrilov has been reconstructed. The emphasis is on the work of M.A. Gavrilov in the field of control of technical systems by means of automation and telemechanics. The work will be useful for young scientists studying research methodology.
 Key words
 automation, telemechanics, control, M.A. Gavrilov, Moscow, V.I. Shestakov, mathematical logic, relay contact circuits
 Reference
 Levin V. I. Mikhail Alexandrovich Gavrilov and the logical theory of designing discrete control systems. Systems of Control, Communication and Security, 2023, no. 4, pp. 283303. DOI: 10.24412/2410991620234283303 (in Russian).