### INFORMATION TECHNOLOGIES AND SYSTEMS

MONITORING AND FORECASTING COMPUTER NETWORK STATE BASED ON THE USE OF HYBRID NEURAL NETWORKS
Saenko I. B., Kotenko Igor V. , Skorik Fadey A.

795

Application of for computer networks state monitoring and forecasting based on high adaptability and resistance of hybrid neural networks to external noise is considered. Models for monitoring and forecasting of computer network states using hybrid neural networks are analyzed. Results of experiments demonstrate that the proposed models afford a rather high precision of classification of current and predicted states of computer network.

MODELING SINGLE-CHANNEL NON-STATIONARY QUEUEING SYSTEMS PRESENTED IN THE FORM OF A CYCLIC GRAPH OF STATES
Vladimir A. Smagin , Gusenitsa Yaroslav N.

801

A principle of probability balance of states is proposed for study of non-stationary queuing system. System of equations for the balance in the complex domain is derived and solved with the use of Laplace images. The inverse Laplace transform is performed for the transition from images to probabilities in the time domain. The developed method is recommended to study non-stationary queueing systems under arbitrary distributions.

TECHNIQUE OF VISUALIZATION OF COMPUTER NETWORK TOPOLOGY FOR MONITORING OF INFORMATION SECURITY
Kolomeets Maxim V., Chechulin Andrey A., Kotenko Igor V.

807

A new visualization technique for computer network topology is developed to be used in SIEM or similar systems for information security monitoring of computer networks. The technique is based on a proposed conception and is reported to improve the effectiveness of security visualization systems. The technique considers the existing visualization models that can be used for visualization of security monitoring data. The technique takes into the account the features of cognitive apparatus of the system operator described in detail in previous papers by the authors. The proposed technique contains all stages of data visualization process and therefore allows for consideration of individual components of visualization system of information security on the architecture level. Generally, the technique unifies the approach to development of security data visualization system for computer network. The results of the study may be used in design of a new visualization system, as well as for evaluation and improvement of existing visualization system efficiency. An example of the proposed technique application to improve the efficiency of network topology visualization based on tree and graph visual model is presented.

### INSTRUMENTS AND SYSTEMS OF AUTOMATIC CONTROL

CORRECTION OF AUTOMATIC CONTROL SYSTEM PROPERTIES BY REFERENCE SIGNAL CONVERSION
Anatoly I. Korshunov

813

A method is proposed for improvement of automatic control system functioning is proposed. The method is based on transformation of reference signal by a specially designed filter. The quality of free processes in the closed loop of the control and stabilization of its dynamic properties are provided by negative feedbacks on controlled variable derivatives. Accuracy in steady state and the quality of transient processes under exposure to reference signal are assured by the reference signal filter. The effectiveness of the proposed method of ensuring the quality of control in the case of reaction to reference signal as well as for non-zero initial conditions is demonstrated by the example of non-minimum phase system.

METHOD OF APPLIED PROBLEMS ALLOCATION TO VIRTUAL MACHINES CONSIDERING THE RELIABILITY OF THEIR SOLUTION
Alexander G. Basyrov, Kazantsev Denis I.

822

The task of optimizing the use of limited resources of memory and the reliability of the computational processes is considered. An algorithm for applied problems allocation to virtual machines is developped. A technique of definition of rational structure of virtual machines is proposed.

SYNTHESIS OF RECURSIVE DISCRETE SYSTEMS IN TIME DOMAIN
Sergey I. Ziatdinov, Leonid A. Osipov

828

Specific problems in development of recursive discrete systems on the base of impulse characteristic readings are considered. By example of the low-frequency filter it is demonstrated that the use of existing methods for real-time calculation of coefficients of difference equation for recursive discrete system gives rise to deviation of the transient characteristics of the discrete system from analogous characteristics of analogous continuous system. The method of calculation of coefficients of difference equation for recursive discrete system with the use of the system transient characteristic is analyzed. The approach is shown to afford dynamic properties of discrete systems coinciding with the dynamic properties of a continuous system throughout the transient response. It is reported that the proposed method may be used for synthesis of recursive discrete systems of both the lower and upper frequencies of almost any order.

MANEUVERING SPACECRAFT TO IMPROVE OBSERVATION CHARACTERISTICS OF LOCAL AREA OF THE EARTH SURFACE
Nikolay F. Averkiev, Vlasov Sergey A., Vyacheslav V. Salov, Vyacheslav V. Kiselev

835

The problem of maneuvering spacecraft to change the orbit in such a way as to multiply the number of the spacecraft passes over a local area on the Earth surface is considered. Conditions of additional observation of the area are derived, and an algorithm is developed for determining the spacecraft orbits parameters providing an improvement of observation characteristics. An example is presented demonstrating the orbit parameters determination with the use of revealed dependences, and the costs of the spacecraft maneuvering are estimated.

DEVELOPMENT OF MATHEMATICAL MODELS OF DYNAMICS OF ELASTIC MEMBRANE SENSITIVE ELEMENTS OF CONTROL SYSTEMS
Kozlov Aleksei S., Labkovskaya Rimma Ya., Pirozhnikova Olga I., Tkalich Vera L.

843

Mathematical models of dynamics of elastic membrane sensitive elements in piezoresistive pressure microsensors are proposed. Modelling is carried out with the use of the method of finite elements by representing the membrane elastic sensitive element by an ensemble of triangular or quadrangular forms. The models account for viscous friction forces associated with the contact between the sensitive element and a viscoelastic adhesive layer. To confirm the proposed models adequacy, calculated model data are compared to results of experimental study. The developed mathematical models for the dynamics of elastic membrane sensitive elements are reported to provide high reliability and good competitiveness of this element base management systems. Created software package designed to work in modern computer environments allows to visualize the results obtained by mathematical modeling of the dynamics of elastic membrane of sensitive elements.

### OPTICAL AND OPTO-ELECTRONIC INSTRUMENTS AND SYSTEMS

THE SYSTEM OF THREE-DIMENSIONAL TOMOGRAPHIC DIAGNOSTICS OF PARAMETERS OF PLASMA FORMATIONS IN THE NEAR-EARTH SPACE
Filonin Oleg V., Petrov Mikhail A.

847

Methods and means of a few-systems three-dimensional tomographic diagnostics of parameters of plasma formation induced in the high-frequency electromagnetic fields in the Near-Earth space are described. Basic parameters of pulsed high-voltage power supply unit used for generating the required electromagnetic field are presented. A display option for luminous intensity distribution as a set of isoparametric surfaces is proposed. A and a developed and A compact three-dimensional tomographic system to be installed on a nanosatellite as well as a ground-based system are developed to study the plasma formations.

EXTENDING ENLIGHTENMENT AREA OF SMALL-SIZE OPTICAL ELEMENT BY COATING WITH A SPECIFIED THICKNESS DISTRIBUTION
Gubanova Lyudmila Alexandrovna, Thang Hoang Long

860

Anti-reflection coating formed by layers with specified distribution of geometric thickness on the surface of optical elements of a very small radius (2—12 mm), is investigated. Distribution of the energy reflection coefficient along the optical element surface is studied. It is revealed that for the given coating structure, the relative size of the enlightenment area defined as the ratio of the radius for the optical element surface where the reflection is less than a certain value (ρ) to the element radius (r), is independent of the curvature radius of the optical element made of homogeneous material. The relative size ρ/r depends of the refractive index of the optical element material and of the antireflection coating design. For the reflection coefficient of less than 1 %, it is possible to obtain the maximum enlightenment area of relative size ρ/r = 80 % with single layer coating, ρ/r = 82 % with double-layer coating, and ρ/r = 81.5 % with three-layer coating. It is shown that multiplying the number of coating layers allows for insignificant extension of the enlightenment area, but makes the coating applicable in a wider range of wavelengths. It is concluded that for extending the enlightenment area, formation of coating layers with a specified distribution of geometric thickness is required.

### INSTRUMENT-MAKING TECHNOLOGY

AN APPROACH TO CREATION OF VIRTUAL ENTERPRISE FOR INNOVATIVE PRODUCTION
Gribovskaya Anna A., Andrey A. Gribovskiy, Yablochnikov Yevgeny I.

867

The problems of expanded enterprise creation are considered, methods of organization of interaction between the customers and the performers in a common information space at the level of sharing information on the let-out product, its structure, structure of a current project in general, and managements of their interaction is proposed. The possibility of organization of virtual enterprise for hi-tech innovative productions is described by the example of a platform of additive production.

THE USE OF SPREADSHEET PROCESSOR FOR SOLUTION OF TECHNOLOGICAL PROBLEMS
Kulikov Dmitry D., Serzh O. Nosov

874

A decision-making system based on referent tables of technological purpose is considered. The system is a component of distributed web-oriented technological integrated environment. Methods to improve the efficiency of decision-making with the use of cloud computing, semantic CAD integration, and a unified information space on the base of the ontological approach are proposed.

### BRIEF NOTES

EXPERIMENTAL SETUP TO STUDY THE EFFICIENCY OF SEMICONDUCTOR PHOTOELECTRODE IN HYDROGEN GENERATOR
Mikhail V. Puzyk, Ermolaev Vladimir S., Ivan A. Ermakov, Papchenko Boris P., Usikov Alexander S.

880

An experimental setup is developed to study the performance of semiconductor photoelectrode hydrogen generator based on gallium nitride. The setup allows simultaneous measurement of the output light flux, photocurrent and photovoltage, the volume of released hydrogen (at the cathode) and oxygen (at the anode).

DYNAMIC MODEL OF DUST CONCENTRATION FOR AUTOMATIC CONTROL SYSTEM OF MICROELECTRONICS PRODUCTION
Aleshkin Nikita A.

884

A refined model of behavior of dust concentration as a climatic parameter of the air of a clean room in microelectronics production enterprise is developed. The adequate simulation model of the climate dynamical system is based on presented mathematical description of the parameter. Results obtained in MATLAB using the developed model confirm the effectiveness of fuzzy control of climate system under unpredictable disturbances when traditional PID controllers are buckling.

CODE SCALE
Ozhiganov Aleхander A.

888

A new type of code scales for digital converters of angle is proposed. The scales are shown provide a basis for design of more adaptable compact transducers as compared with the classical ones. This is achieved by the use in a n-bit code scale of only three code tracks and a smaller number of reading elements.