Summaries of the Issue
The main stages of automatic speech recognition systems over last 50 years are regarded. The attempt is made to evaluate different methods in the context of approaching to functioning of biological systems. The method implementation based on dynamic programming algorithm and done in 1968 is considered as a benchmark. Shortcomings of the method, which make it possible to use it only for command recognition, are considered. The next method considered is based on a formalism of Markov chains. Based on the notion of coarticulation the necessity of applying context dependent triphones and biphones instead of context independent phonemes is shown. The problems of insufficiency of speech databases for triphone training which lead to state tying methods are explained. The importance of model adaptation and feature normalization methods providing better invariance to speakers, communication channels and additive noise are shown. Deep Neural Networks and Recurrent Networks are considered as the most up-to-date methods. The similarity of deep (multilayer) neural networks and biological systems is noted. In conclusion, the problems and drawbacks of the modern systems of automatic speech recognition are described and prognosis of their development is given.
PHOTONICS AND OPTOINFORMATICS
PHOTOELECTRIC AND PHOTOMAGNETIC RESPONSE OF INDIUM-TIN OXIDE FILMS Meshkovsky Igor K, Plyastsov Semyon A
Subject of Research. The goal of the present research is investigation of photoelectric and photomagnetic response of ITO (indium-tin oxide) films under UV laser irradiation. Method. The ITO films were prepared by magnetron sputtering with the thickness equal to 300nm. The films were irradiated by UV laser light with 248 nm wavelength in laser pulse energy range from 10 mJ to 150 mJ by KrF excimer laser. Metallic electrodes were deposited on the films. Information about the films surface topography was obtained by atomic force microscopy and scanning electron microscopy. The film structure was investigated by X-ray diffraction. Main Results. It was shown that voltage appears between metallic contacts under the UV light effect. The electric current was observed through resistive load. The anisotropy of electric field producing photoelectric response was demonstrated for the first time. The appearance of magnetic field under the laser light irradiation was observed for the first time. The dependence of the response voltage on the laser pulse energy was linear over the whole measured energy range. The following physical mechanism was proposed for description of the observed phenomenon: electric voltage is associated with non-uniform distribution of the average crystallite size along the film surface, and, therefore, with mean free path of the charge carriers along the film surface. Photomagnetic response could be associated with collective behavior of the large number of charged particles, created due to high intensity laser irradiation. Practical Relevance. The phenomenon being studied could be applied for creation of new optoelectronic devices, for example, modulators, optical detectors, etc. Particularly, due to linear dependence of photoelectric response on the laser pulse energy, this phenomenon is attractive for manufacturing of simple and cheap excimer laser pulse energy detectors.
POTENTIALS OF RAMAN BASED SENSOR SYSTEM FOR AN ONLINE ANALYSIS OF HUMAN INHALE AND EXHALE Seeger Thomas , Schlüter Sebastian , Lukyanov Gennadiy N
A gas sensor based on spontaneous Raman scattering is proposed for the compositional analysis of single breath events. A description of the sensor as well as of the calibration procedure, which also allows the quantification of condensable gases, is presented. Moreover, a comprehensive characterization of the system is carried out in order to determine the measurement uncertainty. Finally, the sensor is applied to consecutive breath events and allowed measurements with 250 ms time resolution. The Raman sensor is able to detect all the major gas components, i.e. N2, O2, CO2, and H2O at ambient pressure with a high temporal resolution. Concentration fluctuations within a single breath event could be resolved.
ANALYSIS OF PERIODIC NANOSTRUCTURES FORMATION ON A GOLD SURFACE UNDER EXPOSURE TO ULTRASHORT LASER PULSES NEAR THE MELTING THRESHOLD Ivanov Dmitry S, Lipp Vladimir P, Blumenstein Andreas , Veiko Vadim Pavlovich, Yakovlev Yevgeniy Borisivich, Roddatis Vladimir V, Carcia Martin E, Rethfeld Baerbel , Ihlemann Jürgen , Simon Peter
Subject of Study. The mechanism of surface restructuring by ultrashort laser pulses involves a lot of fast, non-equilibrium, and interrelated processes while the solid is in a transient state. As a result, the analysis of the experimental data cannot cover all the mechanisms of nanostructuring. We present a direct comparison of a simulation and experimental results of surface nanomodification induced by a single laser pulse. Method. The experimental results were obtained by using a mask projection setup with a laser wavelength equal to 248 nm and a pulse length equal to 1.6 ps. This setup is used to produce an intensity grating on a gold surface with a sinusoidal shape and a period of 500 nm. The formed structures were analyzed by a scanning and transmission electron microscope, respectively. Then a hybrid atomistic-continuum model capable of capturing the essential mechanisms responsible for the nanostructuring process was used for modeling the interaction of the laser pulse with a thick gold target. Main Results. A good agreement between simulation and experimental data justifies the proposed approach as a powerful tool revealing the physics behind the nanostructuring process at a gold surface and providing a microscopic insight into the dynamics of the structuring processes of metals in general. The presented model, therefore, is an important step towards a new computational tool in predicting materials response to an ultrashort laser pulse on the atomic scale and properties of the modified surfaces. Practical Relevance. This detailed understanding of the dynamics of the process will pave the way towards pre-designed topologies for functionalized surfaces on the nano- and micro-scales.
PERFORMANCE OPTIMIZATION OF THE DIODE-PUMPED SOLID-STATE LASER FOR SPACE APPLICATIONS Arkhipov Denis A., Venglyk Valeriy I, Derevyanko Valeriy A., Egorov Maksim Sergeevich, Rezunkov Yuri A., Stepanov Vladimir V.
Subject of Research. Thermophysical and optical techniques of parameter regulation for diode pumped solid-state laser are studied as applied to space laser communication and laser ranging lines. Methods. The investigations are carried out on the base of the original design of diode pumped solid-state laser module that includes the following: Nd:YAG slab element, diode pumped by 400W QCW produced by NORTHROP GRUMMAN; two-pass unstable resonator with rotation of the laser beam aperture about its axis through 1800; the output mirror of the resonator with a variable reflection coefficient; hyperthermal conductive plates for thermal stabilization of the laser diode generation modes. The presence of thermal conductive plates excludes conventional running water systems applied as cooling systems for solid-state laser components. The diodes temperature stabilization is achieved by applying the algorithm of pulse-width modulation of power of auxiliary electric heaters. To compensate for non-stationary thermal distortions of the slab refractive index, the laser resonator scheme comprises a prism reflector with an apex angle of 1200. Narrow sides of the prism are covered with reflective coating, and its wide side is sprayed with antireflection coating. The beam aperture is turned around its axis through 1800 because of triple reflection of the beam inside the prism. The turning procedure leads to compensating for the output beam phase distortions in view of symmetric character of the aberrations of slab refractive index. To suppress parasitic oscillations inside the slab, dielectric coatings of wide sides of the slab are used. Main Results. We have demonstrated theoretically and experimentally that the usage of hyperthermal conductive plates together with the algorithm of pulse-width modulation provides stabilizing of the diode substrate temperature accurate within ± 0.1 °С and smoothing the temperature distribution along the plate surface accurate within 1 °С. Optical schematic diagram of the laser resonator keeps the laser beam divergence not exceeding a diffraction limit more than twice under a light pump power of 100 W. We have also shown that to increase the lasing efficiency, slab multilayer dielectric coatings made of SiO2 и ZrO2 should be used. Practical Relevance. We have proposed original design of the diode pumped solid-state laser module optimizing the generation and pump modes of solid-state lasers by the temperature stabilization technique for laser diode array and by compensation of the slab aberrations. The techniques are also applicable under space conditions; that is an important factor at developing the space-based lasers.
EXPERIMENTAL COMPARISON OF HOMODYNE DEMODULATION ALGORITHMS FOR PHASE FIBER-OPTIC SENSOR Belikin Mikhail N, Plotnikov Mikhail Yurievich, Vladimir E. Strigalev, Kulikov Andrey Vladimirovich, Kireenkov Alexander Yu.
Subject of Research. The paper presents the results of experimental comparative analysis of homodyne demodulation algorithms based on differential cross multiplying method and on arctangent method under the same conditions. The dependencies of parameters for the output signals on the optical radiation intensity are studied for the considered demodulation algorithms. Method. The prototype of single fiber optic phase interferometric sensor has been used for experimental comparison of signal demodulation algorithms. Main Results. We have found that homodyne demodulation based on arctangent method provides greater (by 7 dB at average) signal-to-noise ratio of output signals over the frequency band of acoustic impact from 100 Hz to 500 Hz as compared to differential cross multiplying algorithms. We have demonstrated that no change in the output signal amplitude occurs for the studied range of values of the optical pulses amplitudes. Obtained results indicate that the homodyne demodulation based on arctangent method is most suitable for application in the phase fiber-optic sensors. It provides higher repeatability of their characteristics than the differential cross multiplying algorithm. Practical Significance. Algorithms of interferometric signals demodulation are widely used in phase fiber-optic sensors. Improvement of their characteristics has a positive effect on the performance of such sensors.
DIRECTIVITY PATTERN INVESTIGATION OF DUAL FIBER OPTIC HYDROPHONE Efimov Mikhail E, Plotnikov Mikhail Yurievich, Mekhrengin Mikhail Viktorovich, Lavrov Vladimir S.
Subject of Research. The paper provides comparison of theoretical and experimental research results of directivity pattern of dual fiber optic hydrophone at various acoustic frequencies. Application of multiple fiber optic transducers in fiber optic hydrophone design placed in sensitive arm of the interferometer gives the possibility for increasing the sensitivity of a fiber optic hydrophone without changing the fiber-optic transducers. In the simplest case, such fiber optic hydrophone can be built on the basis of two spatially separated acoustic transducers. However, this diversity inevitably leads to the directivity pattern unevenness of the fiber optic hydrophone at acoustic frequencies which wavelengths are commensurate with the size of the transducers system. Method. Mathematical model has been created and it became the base material for a theoretical study of two acoustic transducers system in Mathcad environment. Directivity pattern was described by a mathematical formula, depending on the frequency of the acoustic impact and the distance between sensors. To confirm the correctness of theoretical research of the directivity pattern, dual fiber optic hydrophone on Bragg gratings was produced and investigated experimentally. It consists of two consequently welded sensitive elements with a 9 cm distance between them. In trials carried out in open water conditions, fiber-optic hydrophone was placed on the rotator and rotated relative to the piezoceramic emitter for 360 degrees. During investigation, the signal from a fiber optic hydrophone has been recorded simultaneously with the rotation. Further, after the data processing in MATLAB, amplitude of the measured phase signal and the directivity pattern of the test sample were estimated. Amplitude estimation of the measured phase signal and directivity pattern creation of the sample was performed at frequencies equal to 1000, 3000 and 8000 Hz. Main Results. Sensitivity of the dual fiber optic hydrophone is 5.5 rad/Pa at the frequency of 1 kHz, 0.77 rad/Pa at the frequency of 3 kHz and 0.42 rad/Pa at the frequency of 8 kHz. Comparison of the calculated values and experimental results has confirmed the correctness of the proposed model. Possibility of increasing sensitivity of fiber optic hydrophone is shown with the use of multiple transducers without changing its directivity pattern at frequencies up to 3 kHz. At frequencies above 3 kHz dual fiber optic hydrophone with proposed design acquires expressed directivity properties. Practical Relevance. The results can be applied in the design of fiber optic hydrophones in new generation of geophysical equipment, combining compactness and high sensitivity.
SUBJOULE DIODE-PUMPED YTTERBIUM-ERBIUM GLASS LASER WITH CAVITY DUMPING FOR CATARACT EXTRACTION Belikov Andrei , Gagarsky Sergey V., Gubin Anton B, Weiner Samuel Ya., Andrey N. Sergeev, Smirnov N Sergey
Subject of Study. The paper discusses the breadboarding results of compact diode pumped laser. The laser is based on Yb,Er:glass slab active element and frustrated total internal reflection (FTIR) shutter and features of the impact of generated pulses at the water-containing media. The transmitter working in cavity dumping mode provides generation of single microsecond pulses or regular trains of these pulses with peak power up to 100 kW and average output power up to 8 W. The laser allows varying output parameters of radiation in wide range and is designed for the usage in technology and biomedical applications. The possibilities of the laser radiation parameters adapting for application in a compact laser cataract extraction complex are examined. Method. The energy efficient for three level active medium method of lasing pulses repetition rate increasing was investigated, which comprises the generation of pulse trains by several FTIR shutter switching on one pump pulse. We carried out analysis of application possibility for microsecond laser pulses with peak power of tens of kilowatts at wavelength of 1,54 μm in the processing of water-containing tissues. The acoustic response on the interaction of radiation with a model environment was studied. Main Results. In the modulation mode of useful (active) losses lasing pulses have been obtained with microsecond duration and energy more than 100 mJ and trains of pulses with total energy of 0,5 J at the effective pulse repetition rate of more than 50 Hz. The minimal permissible period of laser pulses in train (300 μs) has been established experimentally on the basis of optoacoustic studies. It meets the criteria of operation noninvasiveness consisting in prevention of the risk of posterior lens capsule damage with laser radiation. Practical Relevance. The results obtained with the layout of diode pumped Yb,Er:glass laser with cavity dumping and slab active element are presently record for diode-pumped transmitters generating at the wavelength of 1.54 μm. The measurement results of acoustic response to the impact of light action in a previously unexplored range of light pulses parameters obtained in experiment are useful in assessing application effectiveness of various radiation sources for the treatment of biological tissue.
AUTOMATION OF LENSES CENTERING AT GLUING IN THE FRAME Bao Buy Din, Latyev Svyatoslav M, Theska Rene
This paper discusses the causes of lenses decentration at their gluing in the frame. We give the dependences of displacement value of the centers of curvature for the lens working surfaces from the base frame axis on the primary technological errors of interfaced details. It is shown that some errors of form and position of the frame surfaces produce an effect not on the accuracy of the lenses centering in the frame, but on the accuracy control centering. That causes displacement of the lens working surfaces centers when assembling the lens unit into the objective body. A functional diagram of the station for automated gluing and centering of lenses in the frames is shown; the accuracy of its work is considered. We present the ways of accuracy improvement of lenses centering in the frames carried out on this station, thanks to the centering along not one, but two working surfaces of the lens. The design of composite frames has been developed for performing exact centering of lenses at assembly for the various options of their deployment in the frames. Modernization of technological process for the lens automated alignment has been performed to implement centering along both working surfaces.
AUTOMATIC CONTROLAND ROBOTICS
СREATION OF CORRELATION FUNCTIONS OF LINEAR CONTINUOUS SYSTEMS BASED ON THEIR FUNDAMENTAL MATRICES Vunder Nina A., Nad’kina Ekaterina A., Ushakov Anatoly Vladimirovich, Chugina Julia V.
The paper presents a method of creating correlation matrices and functions of the state vectors and outputs of the linear continuous systems functioning under the conditions of stochastic stationary, in a broad sense, effects. Fundamental matrices form the basis of the method. We have shown that for the linear continuous systems with single dimensional input and single dimensional output the correlation output function of such system can be found as the free movement of this system generated by its initial state. This state is constructed from the variance matrix of the state vector and the transposed output matrix. We have elucidated that when a continuous system belongs to a class of multi-dimensional input – multi-dimensional output systems, the following options are available for solving the problem of creation of the correlation function of a linear system. The first option is to partition the system into separate channels. Then the approach developed for systems with onedimensional input and one-dimensional output is applied to each of the separate channels. The second option is used to preserve the vector nature of the stochastic external influence. It consists in partition of output vector to scalar components by separating output matrix into separate rows with subsequent formation of the correlation function according to the scheme for single dimensional input and single dimensional output type systems. The third option is based on the scalarization of matrix correlation output function by applying the singular value decomposition to it. That gives the possibility to form scalar majorant and minorant of correlation output functions. We have established that a key component of a computational procedure of creating the correlation function of continuous linear system is a variance matrix of the system state vector. In the case of functioning under an exogenous stochastic effect like "white noise" the variance matrix is calculated by solving the matrix Lyapunov equation. We have found out that in the case of an exogenous stochastic effect like "colored noise" capability of using the Lyapunov equation to find the variance matrix of system state arises after aggregated system design composed of the system itself and the shaping filter with "colored noise" at the output. Examples illustrate obtained procedures of creating correlation functions.
СONTROL FOR QUADROCOPTER WITH COMPENSATION OF WIND DISTURBANCE Petranevsky Igor V., Borisov Oleg I., Gromov Vladislav S., Pyrkin Anton Alexandrovich
Subject of Research. The paper presents an output control approach for a class of nonlinear MIMO (Multiple Input Multiple Output) systems. Quadrocopter is chosen to illustrate proposed adaptive control approach based on the high-gain principle, the so-called, “consecutive compensator”. Basic Concepts. The dynamic properties of quadrocopter can be described by a non-linear multi-channel system. Accordingly, the first step is accomplished by its decomposition, whereby the model is divided into two parts: static conversion and several dynamical channels with one input and one output). After the decomposition, a derivation of the simplified mathematical model of the quadrocopter is carried out; and, in addition to the absolute coordinate system, the local system rigidly connected with the robot is introduced. The appropriate coordinate transformation is taken into account. Interim Results. Decomposition of the mathematical model gives the possibility to create control system in two steps. Firstly, the law is applied; in accordance with it the so-called virtual control actions for each model channel of the quadrocopter are generated. A well-known method of robust control, "consecutive compensator", is used here, successfully well-accepted as the most easily implemented one from an engineering point of view. This method gives the possibility to control an object output under its uncertainty quantification. Secondly, the inverse transformation is performed, resulting in real control actions distributed between the system actuators. We assume that wind disturbance affects each channel of the object. What is more, the values and directions of these disturbances are changed negligibly slow. Thus, we can treat them as unknown constants, subject to compensation. Main Result. We have developed a multi-channel control system for the quadrocopter by different methods (decomposition of the mathematical model and the output of its simplified analogue, coordinate transformation, "consecutive compensator"). The obtained closed-loop system has been successfully simulated and corresponding results have been received.
MATERIAL SCIENCE AND NANOTECHNOLOGIES
СHIRAL RECOGNITION OF CYSTEINE MOLECULES BY CHIRAL CdSe AND CdS QUANTUM DOTS Korsakov Ivan V., Mukhina Maria V , Maslov Vladimir G, Baranov Alexander Vasilievich, Fedorov Anatoly V, Gun’ko Yuri K.
Here, we report the investigation of mechanism of chiral molecular recognition of cysteine biomolecules by chiral CdSe and CdS semiconductor nanocrystals. To observe chiral recognition process, we prepared enantioenriched ensembles of the nanocrystals capped with achiral ligand. The enantioenriched samples of intrinsically chiral CdSe quantum dots were prepared by separation of initial racemic mixture of the nanocrystals using chiral phase transfer from chloroform to water driven by L- and D-cysteine. Chiral molecules of cysteine and penicillamine were substituted for achiral molecules of dodecanethiol on the surfaces of CdSe and CdS samples, respectively, via reverse phase transfer from water to chloroform. We estimated an efficiency of the hetero- (d-L or l-D) and homocomplexes (l-L) formation by comparing the extents of corresponding complexing reactions. Using circular dichroism spectroscopy data we show an ability of nanocrystals enantiomers to discriminate between left-handed and right-handed enantiomers of biomolecules via preferential formation of heterocomplexes. Development of approaches for obtaining chiral nanocrystals via chiral phase transfer offers opportunities for investigation of molecular recognition at the nano/bio interfaces.
MICROSTRUCTURING OF SILICON SINGLE CRYSTALS BY FIBER LASER IN HIGH-SPEED SCANNING MODE Skvortsov Albert Matveevich, Trifonova Tatiana A., Huynh Cong Tu
Subject of Study. The surface structure of the silicon wafers (substrate) with a thermally grown silicon dioxide on the surface (of SiO2/Si) is studied after irradiation by pulse fiber laser of ILI-1-20 type. The main requirements for exposure modes of the system are: the preservation of the integrity of the film of silicon dioxide in the process of microstructuring and the absence of interference of surrounding irradiated areas of the substrate. Method. Studies were carried out on silicon wafers KEF-4,5 oriented in the crystallographic plane (111) with the source (natural) silicon dioxide (SiO2) with thickness of about 4 nm, and SiO2 with 40 nm and 150 nm thickness, grown by thermal oxidation in moist oxygen. Also, wafers KHB-10 oriented in the plane (100) with 500 nm thickness of thermal oxide were investigated. Irradiation of SiO2/Si system was produced by laser complex based on ytterbium fiber pulse laser ILI-1-20. Nominal output power of the laser was 20 W, and the laser wavelength was λ = 1062 nm. Irradiation was carried out by a focused beam spot with a diameter of 25 microns and a pulse repetition rate of 99 kHz. The samples with 150 nm and 40 nm thickness of SiO2 were irradiated at a power density equal to 1,2·102 W/cm2, and the samples of SiO2 with 500 nm thickness were irradiated at a power density equal to 2,0·102 W/cm2. Scanning was performed using a two-axis Coordinate Scanning Device based on VM2500+ drives with control via a PC with the software package "SinMarkTM." Only one scan line was used at the maximum speed of the beam equal to 8750 mm/s. Morphology control of the irradiated samples was conducted by an optical microscope ZeissA1M with high-resolution CCD array. A scanning probe microscope Nanoedicator of the NT-MDT company was used for structural measurements. Main Results. It has been shown that at a single exposure of high-frequency pulsed laser radiation on SiO2/Si system, with maintaining the integrity of the SiO2 film, similar symmetric microstructures are formed on the silicon surface. We suggest that the reason for their appearance is the reconstruction of the surface of the silicon arising in the process of recrystallization of the silicon melt surface in the irradiated region of the substrate. The morphology of these microstructures is due to several factors: crystallographic orientation of the plate, original (before the thermal oxidation) reconstruction of the plate surface, elastic stresses of SiO2/Si, laser treatment (thermal, corpuscular, wave). Exposure modes for the observed structures have been determined. Practical Relevance. For the first time in the microstructuring of SiO2/Si by fiber laser in the high-speed scanning mode, images of pieces have been obtained, which can indirectly imply that the reconstruction of atoms on the silicon substrate surface occurs before the thermal oxidation. Clearly marked localization of laser energy at selected irradiation modes enables to assert the possibility of detection and control of structural defects for the elements of semiconductor electronic devices.
DETERMINATION OF SATURATION VAPOR PRESSURE OF LOW VOLATILE SUBSTANCES THROUGH THE STUDY OF EVAPORATION RATE BY THERMOGRAVIMETRIC ANALYSIS Ralys Ricardas V, Yablonsky Gregory S, Slobodov Alexander A
Subject of Study.Research of vapor pressure of low volatile substances is a complicated problem due to both direct experimental implementation complexity and, most significantly, the issues faced correctness of the analysis and processing of experimental data. That is why it is usually required engaging the reference substances (with vapor pressures well studied). The latter drastically reduces the effectiveness of the experimental methods used and narrows their applicability. The paper deals with an approach to the evaporation process description (sublimation) of low volatile substances based on molecular kinetic description in view of diffusive and convection processes. The proposed approach relies on experimental thermogravimetricfindingsina wide range of temperatures, flow rates ofthe purge gas and time. Method. A new approach is based on the calculation of the vapor pressure and uses the data about the speed of evaporation by thermogravimetric analysis depending on the temperature, the flow rate of the purge gas, and the evaporation time. The basis for calculation is the diffusion-kinetic description of the process of evaporation (mass loss) of the substance from the exposed surface. The method is applicable to determine the thermodynamic characteristics for both the evaporation (the equilibrium liquid - vapor) and sublimation (the equilibrium solid - vapor). We proposed the appropriate method of the experiment and analysis of its data in order to find the saturated vapor pressure of individual substances of low volatility. Main Results. The method has been tested on substances with insufficiently reliable and complete study of the thermodynamic characteristics but, despite this, are often used (because of the other data limitations) as reference ones. The vaporization process (liquid-vapor) has been studied for di-n-butyl phthalate C16H22O4 at 323,15–443,15 К, and sublimation for benzoic acid C7H6O2at 303,15–183,15 К. Both processes have been carried in a stream of nitrogen N2 (20-250 ml·min-1); the duration of evaporation-sublimation (each TGA experiment) is 10 hours. As a result, the vapor pressure of these substances has been determined in a wide temperature range; analysis of the dependence for the evaporation coefficients on TGA experiment conditions has been carried out; recommendations on their choice for determination of the enthalpy of vaporization and sublimation of the evaporation rate have been given. Practical Relevance. The presented theoretical and experimental apparatus allows determining the vapor pressure by TGA method for wide classes of compounds with varying volatility (including low volatility). The proposed method requires only necessary data on isothermal evaporation (sublimation) and no standards. It is advisable to use this approach for the study of a wide range of high boiling compounds, such as pharmacologically active substances, oils, "green solvents", including ionic liquids, and others.
STUDY OF CURRENT APPROACHES FOR WEB PUBLISHING OF OPEN SCIENTIFIC DATA Mouromtsev Dmitry I, Lehmann Jens , Semerhanov Ilya A, Navrotskiy Mikhail A., Ermilov Ivan S
Subject of Study. The subject of study of this work is closely related to the development of tools and technologies for Internet publishing of open data in machine-readable formats with regard to data of universities, educational and research organizations and scientific laboratories. We analyze the trends in the publishing formats most commonly used including not only popular formats such as pdf, csv, excel, but also the Semantic Web formats such as RDF. The paper describes the way of scientific data publication in semantic formats on the example of import and convertation of the information from University database. Methods. We describe the methods of publication for scientific open data in the network consisting of a set of transformations of the original data sets to the final semantic representation. These transformation steps include data upload from a relational database, data mapping on the ontological model (schema) and the generation of a set of RDF-triples corresponding to the initial database fragment. A description is given to the popular open data publishing systems, such as CKAN, VIVO, and others. OpenLink Virtuoso system is selected as the primary storage and data publication. The description of RDF data model is used as a way of presenting open data of ITMO University. Main Results. The authors have described the methods of scientific open data publication and identified their shortcomings. To demonstrate the efficiency of the proposed method of university open data publication, a software prototype has been developed available online at: http://lod.ifmo.ru/. The example of the system usage is also given. Practical Relevance. Implementation of the proposed approach will improve significantly the effect of the publication of university open data and make it available for third-party applications, such as applications for information retrieval about educational activities and research results, analysis of scientific activities in universities and their research departments.
PERFORMANCE EVALUATION OF SD-CARDS BY "SYSTEM-ON-CHIP" TECHNOLOGY Kostikova Elena V, Gavrilov Gavrilov A, Mukalo Yuri I., Alekseenko Yaroslav V, Fahmi Shakeeb S
Subject matter. We propose the hardware and software block for performing write or read operation and testing the performance of different SD-cards using the technology of "system-on-chip" in integrated environment by Altera. This task is relevant for the design of high-performance parallel systems on a chip, where the lower limit for writing speed (and/or reading) is critical and significant. Method. The proposed approach is based on three items. First, schemes are used with programmable logic to create a compact hardware and software unit as part of video system on chip. Secondly, reprogrammable structures are applied that support serial and parallel modes of exchange. Thirdly, the increment of data bus width is possible, via the serial transfer and the parallel connection of multiple units simultaneously. Main Results. The analysis of test results of different memory cards has shown that the speed of writing and reading for all cards differs from the declared one by manufacturer, and the error rate of writing (and reading) of data is 30...50% (for reading ~30%). A maximum download speed of memory cards is possible by increasing the number of cascade-connected blocks. The results show that the simplest implementation of this hardware-software unit requires resources of the order of 2000-2500 elementary logic cells. Each cell implements the logical operation "AND-OR with memory", while the resource ЕР3С25F256C8 of the popular chip family Cyclone III consists of 5976 (26%) of these cells with the chip price equal to $5-10 apiece. Practical Relevance. The authors believe that the proposed hardware-software unit can be regarded as the cheapest specialized component in the ECB domestic microelectronics industry to create video information in real time systems.
MODELS OF LIVE MIGRATION WITH ITERATIVE APPROACH AND MOVE OF VIRTUAL MACHINES Aleksankov Sergei M
Subject of Research. The processes of live migration without shared storage with pre-copy approach and move migration are researched. Migration of virtual machines is an important opportunity of virtualization technology. It enables applications to move transparently with their runtime environments between physical machines. Live migration becomes noticeable technology for efficient load balancing and optimizing the deployment of virtual machines to physical hosts in data centres. Before the advent of live migration, only network migration (the so-called, «Move»), has been used, that entails stopping the virtual machine execution while copying to another physical server, and, consequently, unavailability of the service. Method. Algorithms of live migration without shared storage with pre-copy approach and move migration of virtual machines are reviewed from the perspective of research of migration time and unavailability of services at migrating of virtual machines. Main Results. Analytical models are proposed predicting migration time of virtual machines and unavailability of services at migrating with such technologies as live migration with pre-copy approach without shared storage and move migration. In the latest works on the time assessment of unavailability of services and migration time using live migration without shared storage experimental results are described, that are applicable to draw general conclusions about the changes of time for unavailability of services and migration time, but not to predict their values. Practical Significance. The proposed models can be used for predicting the migration time and time of unavailability of services, for example, at implementation of preventive and emergency works on the physical nodes in data centres.
DOMAIN-DRIVEN DESIGN APPLICATION AND IMPLEMENTATION OF INFORMATION SYSTEMS FOR CLIENTS QUEUING SUBJECT AREAS Oleynik Pavel P
The paper deals with domain-driven design applicability of information systems for client queuing subject areas. The following optimality criteria were put forward for the final implementation: the possibility of automation with a single system both for small institution and a whole network of institutions; advanced graphical interface with support for sensor screens; implementation of multi-users account of orders from clients; flexible application architecture with the ability of future enhancement; ability of integration with a variety of peripherals. The necessity of each criterion definition is shown. For implementability estimation, test information system was designed, automating the queuing system. Unified modeling language UML is used. Description of each class functionality is given and the association with other classes as well. Attention is paid to the design of tree (hierarchical) structures and selection procedure of base classes based on the analysis of existing common attributes. For the system implementation, its own development environment SharpArchitect RAD Studio is used, offering MDA approach for implementation of systems based on standardized meta object system. A graphical view of order form developed prototype is presented, composition and structure are described, and notation developed by the author is given simplifying the prototyping process. Approaches to differentiation of access rights for different user roles are shown. Conformity of the received implementation to each selected optimality criterion is determined. Recommendations for further system development are given.
INTEGRITY MONITORING IMPLEMENTATION FOR THE OPERATING SYSTEM IMAGE LOADED THROUGH A NETWORK TO THE THIN CLIENT Gatchin Yuri A, Teploukhova Olga A
The paper deals with the problem of protection for the process of operating system loading from the server to the diskless workstation through a network and the analysis of the existing ways of integrity monitoring for information transferred under network protocols. Within the scope of research, solution is proposed making it possible to perform integrity monitoring of the operating system loaded image before control is transferred to it. For security protection of loading, key information elements are marked which integrity needs to be guaranteed. The developed solution, as an information security product, should meet the requirements of information security and at the same time be compatible to other hardware and software tools used for protection of the automated systems. The proposed solution implements the algorithm of integrity monitoring for an operating system designed with the use of public key infrastructure. Analysis of hardware configuration for the projected solution from the point of view of its usability and administration ease is provided, and possibilities of intruder’s attacks to the protected information are estimated, as well.
METHOD AND ABSTRACT MODEL FOR CONTROL AND ACCESS RIGHTS BY REQUESTS REDIRECTION Koveshnikov Michael G, Shcheglov Konstantin A, Shcheglov Andrey Yu
We have researched implementation problems of control and access rights of subjects to objects in modern computer systems. We have suggested access control method based on objects access requests redirection. The method possesses a distinctive feature as compared to discretional access control. In case when a subject needs to deny writing (object modification), it is not denied but redirected (access rights are not changed, but operation is performed with another object). This gives the possibility to implement access policies to system objects without breaking the system and applications operability, and share correctly access objects between subjects. This important property of suggested access control method enables to solve fundamentally new system objects securing problems like system resources virtualization aimed to protect system objects from users’ and applications attacks. We have created an abstract model, and it shows that this method (access control from subjects to objects based on requests redirection) can be used as self-sufficient access control method, implementing any access control policy (from subjects to objects), thus being an alternative to discretional access control method.
SMARTPHONE-BASED APPROACH TO ADVANCED DRIVER ASSISTANCE SYSTEM (ADAS) RESEARCH AND DEVELOPMENT Lashkov Igor B, Smirnov Alexander V., Kashevnik Alexey M
Subject of Research.The paper deals with findings and presents asmartphone-based approach to advanced driver assistance system (ADAS) research and development.The approach is based on the data of smartphone cameras and sensors. The line of researchis associated with the developmentof mobile advanced driver assistance system (ADAS). Method.The proposedapproach isbased on the use of driver'sand vehicle behavior ontologies. Current ADAS systems can be divided into two main categories according to the method of implementation: mobile applications, manually installed by the driver from the application stores, and safetyhardware and softwaresystems,integrated into vehicles by manufacturesor in the automotive service centers.Mobile application installed on the smartphone uses the built-in rear and front-facing cameras and sensors to monitor both the road and vehicles ahead, and at the same time the driver in order to prevent traffic collisions. The service consists of components for objects recognition in the images obtained with cameras, and components for traffic situation analysis. Main Results. The driver safety mobile application has been developedfor the use on mobile phones.The mobile phone is mounted on the windshield of a car.In case of dangerous event occurrence, the application engine will make an audible or vibration signal to inform the driver to be concentratedand more vigilant. For example, road obstacles, rear-end and stationary vehicle accidents are the most common accident types.The mobile application detects whether a crash is imminent by computing the ‘Time To Contact’ (TTC) taking into account host vehicle speed, relative speed and relative acceleration.If the driver doesn’t maintain safe minimum distance with the car immediately ahead, the mobile application will alert the driver by displaying an attention icon with an audible alert. The dual-camera sensing application is designed to help the drivers increase the trip safety and assess and improve theirdriving skills. Practical Relevance.The proposed approach is designed to help the driver in the driving process, anticipate hazards and provide the driver with appropriate messages through his/her mobile phone.
ENGINEERING AND TECHNOLOGIES
LTE OFFLOADING THROUGH WiFi NETWORKS Steputin Anton N, Romashenkov Nikita O, Fokin Grigoriy A
The subject of the article is Wi-Fi offloading of LTE networks as one of the methods for solving a problem of the lack of availability of network resources in the future. Comparison of mobile networks offloading technologies, such as femtocells, Small Cells and Wi-Fi, is given. Architecture of cooperative LTE+Wi-Fi network including both new network components and new functions for standard LTE network components is presented as well as interaction between components. Special attention is paid to the usage of mobile IP protocols providing connection to the LTE Core both by trusted and untrusted Wi-Fi access. Evaluation of implementation effectiveness and prospective of the technology is given. The relation between amounts of users reconnected to Wi-Fi, data rate of LTE network and amount of access points are submitted as a part of the simulation of user’s equipment transition process from LTE to Wi-Fi network. A conclusion based on the research is made that stepwise phase-in of this technology enables to solve the problem of mobile network resources shortage in metropolises due to permanent traffic growth. It is presented that access points addition and transference of the customers to Wi-Fi network significantly reduce the overload on the base station herewith it increases some data rate with preservation of quality of provided services.
MODELING AND SIMULATION
METHOD OF TRAINING EXAMPLES IN SOLVING INVERSE ILL-POSED PROBLEMS OF SPECTROSCOPY Sizikov Valery S , Stepanov Andrey V
Subject of Study.The paper deals with further development of the method of computational experiments for solving ill-posed problems, e.g., the inverse spectroscopy problem. This method produces an effective (nonoverstated) estimate for solution error of the first-kind equation. Method of Research. An equation is solved by the Tikhonov regularization method. We have obtained nonoverstated estimate for solution error and a new principle for choosing the regularization parameter on the basis of the truncating singular number spectrum of an operator. It is proposed to estimate the truncation magnitude by results of solving model (training, learning) examples close to an initial example (problem). This method takes into account an additional information about the solution. Main Results. We have derived a new, more accurate estimate for regularized solution error using the truncation parameter g. Ways for determining g according to the results of solving model examples are proposed. The method of modeling or training is applied to solving the inverse spectroscopy problem (restoration of a fine spectrum structure by solving integral equation on the basis of an experimental spectrum and the spread function of a spectral device). The method makes it possible to resolve close lines and select weak lines. Practical Relevance. The proposed method can be used to restore smoothed and noisy spectra, in other words, to enhance the resolution of spectral devices by mathematical and computer processing of experimental spectra.
ARBITRARY INTERACTION OF PLANE SUPERSONIC FLOWS Bulat Pavel V, Volkov Konstantin N.
Subject of study.We consider the Riemann problem for parameters at collision of two plane flows at a certain angle. The problem is solved in the exact statement. Most cases of interference, both stationary and non-stationary gas-dynamic discontinuities, followed by supersonic flows can be reduced to the problem of random interaction of two supersonic flows. Depending on the ratio of the parameters in the flows, outgoing discontinuities turn out to be shock waves, or rarefactionwaves. In some cases, there is no solution at all. It is important to know how to find the domain of existence for the relevant decisions, as the type of shock-wave structures in these domains is known in advance. The Riemann problem is used in numerical methods such as the method of Godunov. As a rule, approximate solution is used, known as the Osher solution, but for a number of problems with a high precision required, solution of this problem needs to be in the exact statement. Main results.Domains of existence for solutions with different types of shock-wave structure have been considered. Boundaries of existence for solutions with two outgoing shock waves are analytically defined, as well as with the outgoing shock wave and rarefaction wave. We identify the area of Mach numbers and angles at which the flows interact and there is no solution. Specific flows with two outgoing rarefaction waves are not considered. Practical significance. The results supplement interference theory of stationary gas-dynamic discontinuities and can be used to develop new methods of numerical calculation with extraction of discontinuities.
INFORMATION TECHNOLOGIES IN EDUCATION
LOGICAL CONDITIONS ANALYSIS METHOD FOR DIAGNOSTIC TEST RESULTS DECODING APPLIED TO COMPETENCE ELEMENTS PROFICIENCY Freyman Vladimir I
Subject of Research.Representation features of education results for competence-based educational programs are analyzed. Solution importance of decoding and proficiency estimation for elements and components of discipline parts of competences is shown. The purpose and objectives of research are formulated. Methods. The paper deals with methods of mathematical logic, Boolean algebra, and parametrical analysis of complex diagnostic test results, that controls proficiency of some discipline competence elements. Results. The method of logical conditions analysis is created. It will give the possibility to formulate logical conditions for proficiency determination of each discipline competence element, controlled by complex diagnostic test. Normalized test result is divided into noncrossing zones; a logical condition about controlled elements proficiency is formulated for each of them. Summarized characteristics for test result zones are imposed. An example of logical conditions forming for diagnostic test with preset features is provided. Practical Relevance. The proposed method of logical conditions analysis is applied in the decoding algorithm of proficiency test diagnosis for discipline competence elements. It will give the possibility to automate the search procedure for elements with insufficient proficiency, and is also usable for estimation of education results of a discipline or a component of competence-based educational program.
SYNTHESIS OF 2,6-DIAMINOPYRIDINE-4-NITROPHENOL (2,6DAP4N) COCRYSTAL NANOPARTICLES BY LASER ABLATION METHOD Zulina Natalia A, Denisyuk Igor Yu., Timofeeva Tatiana V
We propose findings for laser ablation of organic materials in liquids as one of the perspective methods of nanoparticles synthesis on their basis. We describe nanoparticles synthesis for 2,6-diaminopyridine-4-nitrophenol (2,6DAP4N) cocrystal by the method of material laser ablation at nanoparticles condensation in liquid (dodecane and polyphenyleneoxide). Laser radiation with wavelength equal to 355 nm, pulse duration - 10 ns, pulse repetition rate - 3.8 kHz, and pulse power density equal to 170 kW/cm2 has been used in the study. Nanoparticles in the form of colloids have been obtained and studied by visible range spectroscopy and optical microscopy. Obtained particles size is around 0.5 μm.