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


Semblance or slowness time coherence is a measure of the coherence of energy distribution be-tween recorded signals at antenna array receivers of acoustic wave logging probe in the coordinates "the reduced time of the wave path from the middle of the antenna array” — “interval time". Several semblance filtering methods are proposed to allow for elimination of the effect of aliasing and to separate the wave packet components.


ANALYSIS OF DYNAMIC CHARACTERISTICS OF COMPLEX GRAPH STRUCTURES Yury A. Ipatov, Alexander V. Krevetsky, Ivan V. Kalagin, Boris V. Sokolov
Quantitative characteristics of graph models are studied. An algorithm is synthesized to analyze the dynamic characteristics of social networks target groups. The developed software toolkit may be useful in analysis of the problems of social network management by automating the tracking of causal indicators of changes in the social graph. The proposed prototype software may be of interest for marketers, system analysts, as well as for specialists involved in analysis of social networks.
The problem of scheduling processor loading in multiprocessor systems of critical purpose is con-sidered. The proposed method of the load planning is focused on hardware realization in connection with impossibility of application of software. A specialized device for the load planning is developed; functional scheme of the device is described, analysis of its hardware and time complexity is presented. By summing up the execution time of operations by the elements of the device, taking into account the increase in the possible number of processors in the system, a dependency diagram is obtained. Analysis of the diagram allows to conclude that the operating time of the processor load planning device grows exponentially with the number of processors in the multiprocessor system, i.e. with the increase in the size of the load queue.
The problem of increasing the speed and throughput of multiprocessor communication networks using input FIFO-queued switches with an output register matrix is under consideration. A packet switch-ing method is proposed featuring a parallel packet transfer pipeline which makes it possible to load packets from the input buffers to the register matrix with no delay needed to spin until the matrix is empty. The proposed method is shown to provide parallel and concurrent packet processing in the input and output circuits of the packet switch. A structural model of a packet switching unit based on the proposed approach is presented. A packet switching algorithm is formulated based on the representation of the set of packets loaded into the register matrix in the form of a packet consistency graph reflecting the packet set ability of being issued in parallel. A graph vertex weight assignment rule is stated taking into account the idle time packets spend in the register matrix. A maximum total weight clique of the consistency graph is shown to be searched for to pick up a proper subset of packets that can be issued currently which makes it possible to reduce the idle time. A formula is deduced to calculate the average time needed for a packet to be transferred through the register matrix of a switch based on the proposed method. The average packet transfer time versus the number of input/output terminals graphs are investigated and the comparison is made for the parallel-sequential switching method and the proposed approach. The developed method is demonstrated to decrease the average packet transfer time by 41 % for all cases of practical significance.


CALCULATION OF ANGULAR RIGIDITY OF ELASTIC ELEMENT FOR MICROMECHANICAL ACCELEROMETER Mariia E. Kalinkina, Kozlov Aleksei S., Labkovskaya Rimma Ya., Pirozhnikova Olga I., Tkalich Vera L.
The problem of creating domestic-produced elements to be used as a base for microelectromechanical systems meeting all modern requirements of the global consumer market. A mathematical model of a new complex-profile elastic suspension element of a mechanical accelerometer is proposed. Various mathematical models for calculating beam (rod) elastic elements of suspensions of micromechanical devices are analyzed, plots for various loading schemes were constructed, supporting reactions, moments and calling forces acting on an elastic element during bending deformations were considered. Based on the analysis, a mathematical model is developed for calculating the angular rigidity of a new complex-sensitive element that takes into account the elastic modulus of the first kind of material of an elastic element, Poisson’s ratio, the radius of cylindrical holes in the elastic element, the width of the element, the thickness of the elastic element in its narrowest part, and the ratio thickness to width with maxi-mum and minimum tolerances.
A method is proposed for constructing private Comparators using time-to-digital converters to esti-mate the dispersion of Allan frequency, as one of the most important parameters of the onboard clock of the spacecraft. It is shown that the Application of integrated time-to-digital converters is shown to be a promising direction of development of the theory of synthesis of frequency Comparators. The main sources of error in the estimation of the mean square relative two-sample frequency deviation are identified: quantization noise, differential nonlinearity, and temperature fluctuations of the full scale error. A structural scheme of the PDA Converter with reduced sensitivity to the nonlinearity of the time discriminator is developed. Computational experiment confirmes the correctness of the results.


The problems arising in the small-scale production of two-stage float gyroscopes in the Central research Institute "Electropribor" are investigated with the help of correlation analysis. Relationships be-tween accuracy characteristics of the azimuth gyroscope and the intermediate parameters of the device fixed in the process of its manufacture, adjustment and testing are considered. Based on the correlation analysis, the influence of the FD factor on the integral estimation of the accuracy of the azimuth gyroscope is confirmed. Dynamics of the sliding correlation coefficient is studied, additional factors affecting the accuracy of the gyroscope (qualification of a gyro motor fitter, type of stator compound) are revealed. Analysis of multiple correlation of a large batch of devices confirmed that the accuracy of azimuth gyroscopes except the FD factor significantly depends on the achieved dispersion of the feedback current at final stages of thermal cycling. The both parameters significantly affect the gyro accuracy on the scale of Chaddock. Correlation analysis of the magnetic characteristics of gyro motor rotors of gyroscopes at different stages of manufacture confirms the difference in chemical composition of the rotor blanks. The use of correlation analysis is shown to be an effective mean in the study of problems arising in small-scale production of various types of sensitive elements in any gyroscopic production.
An overview of existing casting technologies used in the manufacture of products from polymer composite materials is presented. The task of obtaining the required distribution of the filler and the me-thod of achieving it using centrifugal casting is defined. Features of application of technology of centrifugal molding are revealed, and recommendations on reduction of dimensions and energy consumption of drives are formulated. The necessary materials and components of the experimental centrifugal casting plant for testing the effectiveness of the proposed recommendations are specified. Comparative analysis of physical and mechanical characteristics of samples from polymer composites made by gravity and centrifugal casting technologies is carried out. According to the results of the analysis, the use of low-speed drives allows to eliminate porosity and displacement of the filler in the material, and therefore leads to an increase in the mechanical characteristics of the products. The directions of further research are determined.


A method of technological preparation of production of small series of polymer products by injec-tion molding is presented. The necessity of using systems of simulation modeling of the casting process and structured storage of data on the project in a form suitable for search for reuse is shown. Experimental results of injection molding with the use of replaceable forming parts made of composite polymer material using additive technologies are demonstrated.
PARAMETRIC IDENTIFICATION OF A SERVO DRIVE MODEL WITH DEADTIME-TYPE NONLINEARITIES Teresa Orłowska-Kowalska, Sergey Yu. Lovlin, Madina Tsvetkova, Abdullin Artur A, Mamatov Alexander G.
An approach to automatic identification of electrical parameters of a servo drive and a PWM inverter, based on least squares method, is proposed. It is noted that existing methods of parametric identification of servo drives use a linear mathematical model of the object and do not consider nonlinearity, due to the "dead time" and the voltage drop on the power switches of the converter. The output voltage of the PWM inverter is significantly distorted due to these features, which deteriorate the identification results. The proposed identification method uses a model that considers the deadtime effect and the voltage drop on the converter power switches. The new method is shown to enable a higher accuracy of parameter estimation than the method with linear servo drive model.


An approach to the problems of technology synthesis is proposed. The approach allows, from the standpoint of a single multi-model logical-dynamic description, to solve the technology synthesis problems simultaneously with the problems of planning modernization and operation of automated system of production objects control. A comprehensive description of model algorithms developed for solving these problems, is presented.