### INFORMATION TECHNOLOGIES AND SYSTEMS

ASSESSMENT OF FUNCTIONAL DEGENERATION PROCESS OF MULTICHANNEL SYSTEM INCORPORATED A HUMAN OPERATOR
Dudarenko Natalya Alexandrovna, Nuyya Olga S, Serzhantova Maya V, Ushakov Anatoly Vladimirovich

5

Human-operated multichannel functional system is considered to evaluate the possibility of the system degeneration in respect of the individual-operator as well as in respect of the team of individuals forming the multichannel system. The multichannel functional system dimension is determined by the number of individuals involved; the study is based on descriptions of the individuals’ activities using an additive mathematical model of the process "warming-up — fatigue" during the working half-shift. The causes of degeneration are formulated; technical component and the anthropogetic factor are considered as the main. Method for estimating the degeneration process is based on the use of degeneration functional in relation to the criterion matrix. The matrix is constructed in a diagonal form characterizing the normal functioning of the multichannel system, while the emergence of the off-diagonal elements is considered as one of the reasons for its degeneration. Thus, diagonality of the criterion matrix is a necessary but insufficient condition for preservation of equal-pace functioning of separate channels of the system. Accounting for the interval factor inherent in the human operator allows to control the violation of the synchrony of multichannel system. It is proposed to use the integral representation of degeneration functional, which must contain a multiplicative component considering the possible decline of output of multichannel functional system.

ALGEBRAIC METHOD OF ASSESSMENT OF STABILITY OF LINEAR CONTINUOUS CONTROL SYSTEMS WITH INTERVAL COEFFICIENTS
Ivanova Кlara F.

12

A technique is proposed to analyze stability of continuous control systems with interval uncertainty of coefficients of stationary equations. The risk of instability is shown to increase with increasing error (range of interval boundaries) of matrix elements of the system of equations, resulting in the transition from asymptotic stability to instability. The stability analysis of the system with interval coefficients, based on formalization of point systems of the equations, is based on construction of optimal angular matrices. The obtained estimates of stability of interval system of the equations are in good agreement with the results the stability analysis of the family of characteristic polynomials performed by V. L. Haritonov.

SCALAR EVALUATION OF QUALITY OF VECTOR PROCESSES IN DISCRETE MULTICHANNEL SYSTEM WITH UNCERTAIN PARAMETERS
Pavlov Andrey S., Ushakov Anatoly Vladimirovich

22

Scalar methods of evaluation of upper bound of vector processes are considered using discrete multichannel system with uncertain parameters as an example. The uncertainty of the parameters is such that it turns out to be correct to use the apparatus of the first-order parametric sensitivity functions. As a scalarizing function, such common norms as Euclidean and infinite are used. The advantages and disadvantages of the methods are demonstrated.

### DEVICES AND SYSTEMS OF AUTOMATIC CONTROL

ROBUST OUTPUT CONTROL OF TWIN ROTOR NONLINEAR MULTICHANNEL OBJECT
Sergey A. Vrazhevsky, Margun Alexei A., Bazylev Dmitry N, Zimenko Konstantin A., Kremlev Artem Sergeevich

32

The problem of robust control over multi-dimensional onlinear systems is addressed. The class of nonlinear control objects with parametric uncertainties is considered in the presence of external unknowns of bounded perturbations. An approach to the control problem based on the method of sequential compensator is proposed. Results of experimental study carried out with the use of the laboratory bench "Twin Rotor MIMO System" confirme the developed control algorithm efficiency. Based on the results of the experiment, it is shown that the method of a sequential compensator provides a higher quality of transient processes and accuracy in the steady-state regime in comparison with the control of the proportionalintegral-differential control.

ANALYSIS OF REMOTE ACCESS SAFETY USING THE INTEL MANAGEMENT ENGINE
Ogolyuk Alexander A., Shabalin Anton V.

41

Several hidden details of the implementation of UEFI BIOS subsystems and Intel Management Engine of modern x86-based computers are discussed. Results of security analysis of the described subsystems and the possible consequences of their discredit ar presented. Basic principles of possible attacks on the subsystems under consideration are described. The possibility of changing the current situation is explored and approaches are proposed to improve the security of the systems based on the Intel x86 platform.

### COMPUTING TECHNIQUE

FEATURES OF HAMMING CODES APPLICATION IN SELF-CHECKING TEST CIRCUIT ORGANIZATION
Sapozhnikov Valery V., Sapozhnikov Vladimir V., Ephanov Dmitry V.

47

Hamming code properties are analyzed for the case of error occurrence in data bits only; it is actual for the solutions of error detecting systems synthesis. Features of detection of different type (monotonous, symmetric, asymmetric) errors in Hamming code data bits are described. It is shown that ratio of different type of undetectable errors of given multiplicity to the total number of undetectable errors of given multiplicity does not depend on data vector length and is a constant. Results of benchmark experiments demonstrate that application of Hamming code for the organization of self-checking test circuits may be more effective than the use of standard duplication circuit both for technical implementation complexity and for detection of single faults of circuit’s inner structure.

MODIFICATION OF THE TLS PROTOCOL ON THE BASIS OF A LOW-DENSITY CRYPTOSYSTEM WITH SHARED MEMORY
Metlinov Alexander D.

60

Features of the TLS protocol modifications with the use of a model of knapsack cryptosystem with shared memory are considered. The existing security protocols for the transmission of messages in the communication channel are shown to have their own significant disadvantages and therefore to be not quite safe for information transmission. To improve the efficiency of the organization of a secure communication channel in TCP/IP networks, it is proposed to use algorithms of symmetric backpack cryptography, a CRCvariant of a symmetric backpack cryptosystem, and a hash function based on it additional of the existing crypt algorithms at all stages of the TLS protocol operation.

### SCIENTIFIC AND PRACTICAL DEVELOPMENTS

INSTRUMENTAL METHOD OF VENTILATION AND SMOKE CHANNELS SURVEY IN GASIFICATED PREMISES OF RESIDENTIAL AND PUBLIC BUILDINGS
Silenko Evgeny М., Silenko Sergey Е., Bodnya Alexander S., Silenko Viktoria E.

65

A method is proposed for measuring air flow in ventilation and negative pressure in smoke channels. The method is based on the relationship of these parameters to the local flow velocity at the center of a measuring channel of the circular section, made in the form of a nozzle. A portable multipurpose device is developed to control the three parameters - the air flow through the ventilation duct, the depression in the smoke channel, and the direction of the flow. Description and a scheme of the device are presented, as well as the scheme of the calibration instrument for determining the metrological characteristics of the measuring device.

ALGORITHM FOR HUE CONTRAST TRANSFORMATION IN THE LAB COLOR SPACE
Grebenyuk Pavel E., Alexey M. Chmutin, Vladimir Chuiko

71

An analysis of modern computer graphics software tools to operate hues is carried out. The problem of hue-contrast transformation in the Lab color space is actualized. It is shown that the existing toolkit is not capable to provide system hue-contrast management in Lab. For this color space, an original algorithm of hue-contrast variation is presented and tested.

DEVICE FOR MEASURING THE MAGNETIC SUSCEPTIBILITY OF LIQUIDS OF VARIABLE COMPOSITION
Sazonov Sergey N.

78

A scheme of instrument for measuring the relative magnetic susceptibility of weak-magnetic liquids is proposed. The operation principle of the measuring device is based on the effect of change in magnetic field induction inside a cavity of hard-magnet ball when it is enveloped by the spherical layer of the substance under measurement. The measurement of susceptibility may be executed not only with a nonmoving object but in flowing liquid, too. Resolution of the instrument is predicted to be 10–9 in CGS system of units. The resolution enables evaluation of the ethanol concentration in water with the accuracy of about one volume percent.

GENERALIZED CONCEPTUAL DATA MODEL OF ELECTROPHYSIOLOGICAL STUDIES OF THE GASTROINTESTINAL TRACT
Popov Aleksandеr I.

84

Electrophysiological methods for analyzing the contractile activity of the gastrointestinal tract — electrogastrography and electrogastroenterography — are considered. The analysis of actual studies on the structure of electrogastrography and electrogastroenterography data is presented. The data generalization is used to create a data-signal-measurement-survey model. Some ways of implementing the model are considered.