ISSN 0021-3454 (print version)
ISSN 2500-0381 (online version)
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Summaries of the issue

SYSTEM ANALYSIS, CONTROL, AND INFORMATION PROCESSING

259
On the example of 50 programs in the machine codes for an educational computer, metrics are defined that allow analyzing the frequency of use of machine instructions. The percentages of microinstructions used and repeated during micro-program control implementation established during the analysis, confirm the applicability of the 20/80 principle - the Pareto principle for processor operation. A conclusion is made about the redundancy of the system of computer commands, which leads to the complication of the processors architecture. Groups of instructions and microinstructions with a minimum number of repetitions (significance) are identified, and some of them can be removed in order to simplify the computer architecture.
ALGORITHM OF ADAPTIVE ESTIMATION OF PARAMETERS FOR A CLASS OF NONLINEAR NON-STATIONARY SYSTEMS Pyrkin Anton Alexandrovich, Bobtsov Alexey Alexeevich, Nguyen Huc Tung
266
The problem of identification of unknown parameters for a class of non-stationary nonlinear systems is considered. It is assumed that non-stationary parameters can be represented as outputs of linear generators with unknown state matrices and initial conditions. The system state variables are supposed to be available for measurement. At the first step of the developed algorithm, the problem of parametrization of the initial dynamic model is solved to obtain a linear static regression model. At the second step of the algorithm, the unknown constant parameters of the linear regression model are estimated. Then the synthesis of observers for non-stationary parameters is performed. Presented results of computer simulation demonstrate the proposed algorithm efficiency.
276
A compensation-type pendulum accelerometer is considered as an electromechanical measuring device, and factors affecting its accuracy characteristics are analyzed. It is shown that the errors of the inverse converter compensating the input action are not reduced by the elements of the feedback circuit. A mathematical model of the error of the compensation accelerometer in the static mode of operation is developed. The influence of the design and electronic-converter elements of the accelerometer on the overall measurement error is estimated. It is shown that one of the main sources of error in converting the measured acceleration into an electrical signal is a device summing the measured value and the value of the compensating effect. The error of comparing these two signals by the summing device determines the error of measuring the input acceleration by the accelerometer.
285
A method of data transmission using a scheduler and a delivery control function in software-defined networks is proposed, and an algorithm for its operation is developed. A possible variant of the hardware implementation of the OpenFlow switch, which performs the processing and transmission of heterogeneous traffic, is considered. The features of the functioning of the main nodes of the switch - the scheduler and the delivery time validator - are described. On the basis of the proposed method, modeling of software-defined networks using the apparatus of Petri nets is carried out. The probabilistic-temporal characteristics of the model are studied, and the method is verified using Petri nets. The effectiveness of the proposed method lies in the fact that the switch load remains constant due to more flexible scheduler settings (instead of using hard timeouts), as well as the possibility of early transmission of standard data.
297
The problem of estimating the orientation parameters of a spacecraft observed from a space robot is considered, and various approaches to its solution are presented. Results of the study of the accuracy of two approaches to estimating the parameters of the spacecraft orientation from results of a space robot observation using the technical vision methods and convolutional neural networks, are presented. In the first approach, the neural network is used to determine the screen coordinates of the object's special points projections in the image. The second approach is based on the use of a trained convolutional neural network, which directly generates the Euler angles from the observed image.

OPTICAL AND OPTO-ELECTRONIC INSTRUMENTS AND SYSTEMS

306
Abstract. A method for creating an optical scheme and the principle of using photoactive samples of chiral nematic liquid crystals for optical molecular generation of localized chiral structures are considered. It is shown that the existence of two different static localized chiral structures with sizes of about 25 and 10 µm is possible, depending on the power of the UV laser beam. The processes of reconfiguration of localized chiral liquid crystal structures into each other and into a completely frustrated state of a chiral nematic liquid crystal film are described. These localized structures can be used as miniaturized tunable optical elements for focusing and structuring transmitted light beams.
MATHEMATICAL MODELING OF THE OUTPUT SIGNAL FOR DIFFERENT PHOTODETECTOR APERTURE GEOMETRIES IN INTERFERENCE SYSTEM OF INTERFEROGRAM ANALYSIS Majorov Evgeniy E., Aleksander V. Arefiev, Yuriy M. Borodyansky, Ramiz B. Guliyev, Dagaev Alexander V., Vera P. Pushkina
313
Mathematical modeling of the output signal of interference system for interferogram analysis is carried out for different photodetector aperture geometries. The measuring system output signal is analyzed using the integration method. The requirements for changing the interference fringes parameters are determined. According to the performed analysis, it is necessary for the bandwidth to be much larger than the photodetector aperture when carrying out measurements.

INSTRUMENTS AND METHODS FOR MONITORING THE NATURAL ENVIRONMENT, SUBSTANCES, MATERIALS AND PRODUCTS

NUMERICAL AND EXPERIMENTAL MODELING OF THE ACOUSTIC-ELECTRICAL METHOD FOR NON-DESTRUCTIVE TESTING OF SOLID-STATE DIELECTRICS Anatoly A. Bespalko, Denis D. Dann, Pavel I. Fedotov, Sofia A. Dmitrieva, Junhua Luo
320
Abstract. To develop a complex acoustoelectric method for non-destructive testing, mechanoelectric and acoustoelectric transformations are numerically and experimentally studied on the example of magnetite ore samples and model defective dielectric structures based on cement-sand mixtures. Results of calculations of stress concentration at cracks of different sizes during an external deterministic acoustic pulse propagation along the sample are presented. Results of experimental studies of electromagnetic emission of samples of magnetite ore containing calcite and magnetite under uniaxial compression to fracture are demonstrated. The possibility of reliable determination the appearance and development of destructive zones in dielectric materials from the spectra of electromagnetic responses during acoustoelectric transformations is revealed. Results concerning changes in parameters of electromagnetic responses of a cement-sand mixture with defects under external pulsed acoustic action in the process of stepwise loading by compression and shear are presented. As inclusions (defects), magnetite ore and fluoroplastic are used, which have, respectively, a higher and lower acoustic impedance than the model sample material. The effect of duration of external pulsed acoustic excitation on parameters of electromagnetic responses during stepwise loading of model samples is considered.
335
Abstract. The article is devoted to the development of a fiber-optic cuvette meter of methane concentration at oil and gas enterprises. The subject of the study is the development of theoretical foundations for optimizing the design of such a meter in which the main operating indicator of the meter reaches an extreme value. The purpose of the work is to investigate the possibility of finding the optimal relationship between the main regime indicators, at which the selected optimization criterion reaches the maximum value. An unconstrained optimization problem is formulated, in which an additional condition is added to the optimization functional using the Lagrange multiplier. A form of functional connection between the main regime indicators has been obtained, in which the goal functional reaches a minimum value. The found relationship between the main indicators is characterized as the worst, which should be avoided in practice.

METROLOGY AND METROLOGICAL SUPPORT

342
Abstract. A digital temperature difference meter is proposed, in which platinum resistance thermal converters are used. The meter contains a measuring circuit, an analog-to-digital converter (ADC), and a digital indicator. An operational amplifier is introduced into the measuring circuit to create a countercurrent in one of the resistance thermal converters included in the feedback circuit of the operational amplifier. The thermal converters are connected via a four-wire communication line. The line wire resistances do not affect the measurement result and therefore do not need to be adjusted. A push-pull integration ADC is applied. The differential measuring inputs of the ADC receive voltage drop signals from corresponding thermal converters. One of the reference inputs of the ADC receives a voltage drop signal across the reference resistor, in which the measuring current flows through the thermal converter. This makes the output code of the ADC to be independent of the measuring current. The metrological analysis of transformation of the thermal converter resistance difference into the digital code is performed, the revealed sources of errors are the zero-bias voltage of the operational amplifier, inaccuracy and instability of the reference resistor. It is established that the considered scheme of the measuring circuit is suitable for use in narrow-limit temperature difference meters. In this case, the communication lines of thermal converters can have any length and do not need the connecting wires resistances to be adjusted.