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

INFORMATION TECHNOLOGIES AND SYSTEMS

ESTIMATION OF PERIODS OF NONSTATIONATY PROCESSES IN CLOUD SYSTEMS Zhmylev Sergey A., Martynchuk Ilya G., Kireev Valery Yu., Aliev Taufic Ismailovich
645
The problem of automated evaluation of load process period in cloud systems is considered. A common approach to load simulation for such systems implies the stationary nature of incoming requests flow, which results in inadequate matching of the models to the objects under investigation. To automatically construct an adequate analytical model, it is necessary to estimate the length of the loading process period from measured data. A numerical method of automated period estimation for any periodic functions is proposed. The method allows real-time processing of measured values, restoring missing data by interpolation of known neighboring values. Pearson correlation coefficient is chosen as a criterion to calculate functions similarity. It’s proposed to store arrays of sums of mean values and standard deviation values in the main memory to improve the method’s performance. Computational complexity of the method is reduced to polynomial, which means that the method could be implemented even in the embedded systems. Period estimation accuracy is demonstrated by presented results of numerous experiments with ideal, randomly noised, and real signals.
MODELING OF FUNCTIONALLY STABLE NAVIGATION INFORMATION SYSTEMS Коrolev Alexander N., Кем О. В., Mironichev Vitaly A.
652
General problems of navigation and information system modeling are considered with the use of the mathematical apparatus of category theory and graph theory for analyzing and evaluating the possibility of ensuring the functional stability of systems under destructive influences.
660
A method of management of the genetic algorithm mutation procedure is developed. The method uses a coefficient that changes its value in the process of searching for an extremum of a multiple parameter function with respect to a dependence that is close in form to the evolutionary law. Results of experiments are presented to demonstrate the possibility of increasing the rate of convergence of the genetic algorithm due to correction of a mutation probability when searching for the test function optimum.

INSTRUMENT-MAKING TECHNOLOGY

ANALYSIS OF THE SCHEME OF GRINDING OF PARABOLOID ROTATION SURFACE BY THE "KNIFE" METHOD Zverev Victor Alexeevich, Nikolayeva Yulia S., Timoshchuk Irina N.
666
Application of the method of lapping for grinding spherical surfaces and treating paraboloid of rotation surfaces using flat tool are considered. Analysis of the forces determining the specific pressure of the tool on the surface to be treated is performed.
672
Advantages of using thermoplastic polymer composite materials and non-autoclave technologies in the aerospace industry are considered. A robotic complex was developed to implement the technology of automated laying of products from such materials. The results of physical and mechanical tests of samples made of thermoplastic prepreg confirm the competitiveness and advantages of thermoplastic materials and the technology being implemented.
TECHNICAL REALIZATION OF UNIFIED SPACE PLATFORMS Коrolev Alexander N., Pichurin Yury G., Radkov Alexander V., Rudakov Valery B.
678
Prerequisites and peculiarities of small spacecraft (SSC) creation based on unified space platforms (USP) are considered. An analysis of new progressive technical solutions is performed; implementation of the solutions is anticipated to provide a high level of perfection for SSC, developed on the base of the USP concept. Implemented technical solutions aimed at improving the spacecraft reliability, are also analyzed. Several problematic issues of the technical implementation of the USP are discussed. One of the problems relates to the USP adaptability to construction of a "constellation" of spacecrafts with a flexible architecture for solving a wide range of problems. It is concluded that construction of unified space platforms as the base for development of space vehicles for various special purposes, is one of the most important trends in space instrumentation.

SCIENTIFIC AND PRACTICAL DEVELOPMENTS

685
The complex of scientific and educational activities aimed at increasing the motivation of modern youth to engage in technical creativity in the aerospace field is analyzed. Special attention is paid to the forms of organization of work with young people, contributing to the involvement of talented students in the work on promising research projects in satellite and rocket engineering. Experience of the European Space Agency and NAROM (Norwegian National Center for Space Education) involving multilevel training of specialists is described. Results and plans of deploying multi-level training of specialists in Russia are also examined. The achievements of the St. Petersburg University of Aerospace Instrumentation in cooperation with industrial enterprises and organizations engaged in the development of modern technologies for space probing in the field of student and innovative projects of the Earth monitoring from space, the development and construction of microsatellites are discussed. The experience in participation in international youth competitions CANSAT and the organization of similar competitions in Russia are noted.
692
Methods of design and employment of nanosatellites are described. A review of the CubeSat standard is presented. Technology of construction of nanosatellites on the base of multi-purpose platform "Synergy" of block-modular type is considered.
701
Influence of magnetic field gradients on the test body of the absolute ballistic gravimeter ABGVNIIM-1 is considered. Based on the protocol for measuring the magnetic field in the working region and data on magnetic fields of the pump magnetic system of the gravimeter, gradient models are created. Using the finite elements method, deviation of measured value of free fall acceleration from the initial one is calculated. Recommendations for design of the test body and the whole instrument are formulated.
METHOD FOR LIMITING THE EFFECTIVE VALUE OF THE CURRENTS OF SERVO DRIVE PMSM MOTOR Lovlin Sergey Y, Polyakov Nikolay A, Abdullin Artur A, Lukichev Dmitry V. , Demidova Galina L.
706
The problem of maintaining the permissible thermal mode of PMSM motor of servo drive is considered. An important feature of the drive is intimated to be the wide range of speeds from several degrees to tens of degrees per second. A novel method of limiting the effective value of the phase currents of PMSM motor, which allows to develop high moments for a short period of time while maintaining the permissible thermal mode, is presented. An advantage of this method is that there is no need to install temperature sensors. The proposed method is tested with a servo drive model in Simulink / MatLab.
ISSUES OF DEVELOPMENT AND INTEGRATION OF VIRTUAL RECEIVING STATION FOR THE EARTH REMOTE SENSING DATA WITH A DISTRIBUTED INFORMATION SYSTEM Makerov Alexander I., Dobrolinskaya Ekatherina V., Ubrantseva Ekatherina A., Zheleznov Sergey A., Chernyakov Vadim G., Seleskiy Alexey D.
713
Capabilities and methods of creation, as well as the prospects and applications of virtual receiving station for the Earth remote sensing (ERS) data based on the information complex of ERS of the Russian Federation. Several problems related to formation of requests for remote sensing data by the end user have been identified. A comparative analysis of foreign companies providing remote sensing data is presented. Based on the analysis, a variant of the virtual receiving station functioning is proposed to automate the process of obtaining information.
INCLUSION OF GRADIENT STRUCTURES IN TRADITIONAL THERMAL PROTECTIVE COATINGS TO REDUCE TEMPERATURE ON THE HULL OF DESCENT SPACECRAFTS Korovin Gennady V., Kulakov Vyacheslav A., Zaytseva Marina K., Savushkina Svetlana V.
720
The problem of creation of thermal protection of space vehicles (spacecrafts) entering the atmosphere of planets is considered. The problem is regarded as an urgent one because the thermal protection is designed to provide thermal regimes and reliability of spacecraft instruments and systems. Results of a study on the possible improvement of the thermal protection of space vehicles by developing a technology for creating thermal protective coatings of a gradient structure of various compositions for integration into a thermal protection package to reduce the temperature on the spacecraft body are presented.

BRIEF NOTES

725
The problem of determining the size and localization of the marking area of the object is solved by analysis of the object image. Using the detected repetition frequency of text labels, the size of the area containing the marking pattern is determined. To localize the label area, a new type of matrix filter is developed, based on the obtained data on the size of the sought domain and a priori knowledge of the number and length of the label strokes. Application of the filter allows for determining the label center by maximal brightness of corresponding pixel.
SIMULATION, ANALYSIS, AND PREDICTION OF MEDICAL CARE PROCESSES FOR CARDIOLOGICAL IN-PATIENTS Abuhay Tesfamariam M., Kovalchuk Sergey V., Balakhontceva Marina A., Boukhanovsky Alexander V
730
A simulation model of the patient flow for estimating the load of a specialized medical center is developed using empirical data, as well as simulating discrete events, and queuing theory. The results of the simulation demonstrate an inverse relationship between the rate of arrival of patients and their number, and show that the pooling of all resources into one common fund is not always a solution to reduce the burden on a particular department.
734
Results of the study of removal efficiency of cataract-affected lens of the eye under the action of microsecond pulses of Yb, Er: Glass-laser are presented. The efficiency of lens removal is discussed in relation to the number of laser pulses, their energy, as well as the distance between the end of the optical fiber and the surface of the bioobject.