Summaries of the Issue
FOTONICS AND OPTOINFORMATICS
EXTRACTION OF MATERIAL PARAMETERS FOR PLASMON MULTILAYER FROM REFLECTION AND TRANSMISSION COEFFICIENTS Orlov Alexey Anatolievich, Elizaveta A. Yankovskaya, Sergei V. Zhukovsky, Belov Pavel Alexandrovich
The paper deals with acquisition and analysis of permittivity and permeability for a finite sample made of multi-layered metal-dielectric nanostructure –plasmon multilayer referred to a class of electromagnetic metamaterials. Metamaterials are artificial structures, periodical as a rule, with characteristic unit cell sizes much smaller than the wavelength in vacuum, having unusual properties not met in nature. For example, metamaterials open the way to fabrication of optical materials with permeability substantially differing from unity - the task considered as unrealizable for a long time. The classical Nicolson-Ross-Weir method has been applied for extraction of material parameters describing an electromagnetic behavior of the plasmon multilayer from reflection and transmission coefficients. Strong resonance-type magnetic activity in the optical frequency domain is observed in the metamaterial under consideration. Magnetism appears due to strong spatial dispersion inherent to the plasmon multilayers. Position of the permeability resonance is located exactly in the epsilon-near-zero region. It is shown how the resonance can be repositioned by means of the filling factor changing. Observed magnetic activity reaches the steady state with multilayer thickness equal to a few dozens of layers. Plasmon multilayers are sug-gested as robust and effective optical materials with a strong magnetic response in the whole optical domain.
PLASMON SOLITONS, KINKS AND FARADAY WAVES IN TWO-DIMENSIONAL LATTICE OF METAL NANOPARTICLES Noskov Roman E , Smirnova Daria A, Lapshina Nadezhda S
We consider nonlinear discrete modes in a two-dimensional lattice of metallic nanoparticles driven by optical radiation at a frequency close to the frequency of the surface plasmon resonance of an individual nanoparticle. We suppose that the particles are small enough and the interparticle distance is large enough to treat nanoparticle within point-dipole approximation. We also assume that nanoparticles are made of silver and possess an intrinsic nonlinear Kerr-type response. Since each particle acts as a resonantly excited oscillator with slow (in comparison with the light period) inertial response, we employ a slowly varying amplitude approach to describe dynamical behavior of particle polarizations. Following a standard linear stability analysis, we obtain areas of bistability and modulation instability for the homogeneous stationary solution of the corresponding dynamical system in the plane ‘intensity-frequency’. Based on these data, we present and analyze examples of generation of plasmonic Faraday waves, stable two-dimensional solitons, oscillons, and kinks (switching waves), which separate two different homogeneous states of particle polarizations. We also discuss realistic duration of the laser pulse which should be large enough to cause the formation of the considered nonlinear modes and small enough to prevent particle ablation.
STUDY OF CHARACTERISTICS OF SPECTRAL INTERFERENCE SIGNALS IN THE NEAR INFRARED SPECTRAL RANGE Gurov Igor P
Peculiarities of signals formation in spectral interferometry and optical coherence tomography are considered. Basic relations are given defining minimal depth coordinate value of an investigated object, where single period of spectral interference signal is acquired and a value of the wave length increment set according to the depth range, where spectral interference signals are registered. The estimate of resolving power of the spectral interfereometry and optical coherence tomography systems with tunable wave length is given taking into account a spectral range of wave length tuning. It is shown that the ratio of the wave length mean value and the range of the wave length tuning defines the resolving power in depth of an investigated object, while the maximum depth range, within which investigation of an object’s micro structure by the spectral optical coherence tomography is possible does not depend on the range of the wave length tuning being determined by the wave length (wave number) tuning step. Numerical estimates of the parameters mentioned above are presented when using light sources in near infrared range, as well as relations and estimates of interference fringe visibility dependent on registered relative intensity of a measuring wave.
LOGIC WITH EXCEPTION ON THE ALGEBRA OF FOURIER-DUAL OPERATIONS: NEURAL NET MECHANISM OF COGNITIVE DISSONANCE REDUCING Pavlov Alexander V
A mechanism of cognitive dissonance reducing is demonstrated with approach for non-monotonic fuzzy-valued logics by Fourier-holography technique implementation developing. Cognitive dissonance occurs under perceiving of new information that contradicts to the existing subjective pattern of the outside world, represented by double Fourier-transform cascade with a hologram – neural layers interconnections matrix of inner information representation and logical conclusion. The hologram implements monotonic logic according to “General Modus Ponens” rule. New information is represented by a hologram of exclusion that implements interconnections of logical conclusion and exclusion for neural layers. The latter are linked by Fourier transform that determines duality of the algebra forming operations of conjunction and disjunction. Hologram of exclusion forms conclusion that is dual to the “General Modus Ponens” conclusion. It is shown, that trained for the main rule and exclusion system can be represented by two-layered neural network with separate interconnection matrixes for direct and inverse iterations. The network energy function is involved determining the cyclic dynamics character; dissipative factor causing convergence type of the dynamics is analyzed. Both “General Modus Ponens” and exclusion holograms recording conditions on the dynamics and convergence of the system are demonstrated. The system converges to a stable status, in which logical conclusion doesn’t depend on the inner information. Such kind of dynamics, leading to tolerance forming, is typical for ordinary kind of thinking, aimed at inner pattern of outside world stability. For scientific kind of thinking, aimed at adequacy of the inner pattern of the world, a mechanism is needed to stop the net relaxation; the mechanism has to be external relative to the model of logic. Computer simulation results for the learning conditions adequate to real holograms recording are presented.
ANALYSIS METHOD OF ANISOTROPIC LIGHTGUIDE h -PARAMETER DEPENDENCE ON ITS BENDING RADIUS Shramko Oleg A, Rupasov Andrei V, Novikov Roman L, Aksarin Stanislav Mikhailovich
The paper deals with the known methods for h-parameter measuring of the fiber and the new developed interferometry method. Analysis method of the anisotropic lightguide h-parameter dependence on its bending radius for the optical fiber is proposed. Micro bends of a fiber, being the defects of a sensitive element winding in a fiber-optic gyroscope (FOG), lead to the deterioration of a number of optical characteristics, in particular, the extinction coefficient and the cross-coupling coefficient. As a result, it worsens the FOG accuracy. The way of increasing the measurement accuracy and adaptation of the h-parameter measuring process to the existing technology of fiber-optic gyroscopes production is proposed. The mechanism of the polarization properties influence on the FOG accuracy is described through the analysis of secondary waves induced by the polarization transformation in the optical circuit. The influence estimation of the measured parameter on the FOG accuracy characteristics is given. For the gyro with the polarizer extinction coefficient equal to 27 dB, h-parameter 2·10-5 m-1, the length of the fiber loop 1500 m and the length of depolarization 4 mm the amplitude phase error does not exceed 3.2·10-5 rad and the intensity phase error is 2·10-10 rad.
PROCESS METHODS WITH LOW LEVEL OF OPTICAL LOSSES FOR THE MICROSTRUCTURED FIBER LIGHT GUIDES Korobeynikov Anatoliy Grigorievich, Gatchin Yuri A, Dukelskiy Konstantin V, Ter-Nersesyantz Egiche Vavikovich
The paper deals with results of the technology process development for the microstructured fiber light guides. Light guides with one or two cycles of the openings, processed by two-phase technology were created during carried out research. The use of two cycles makes it possible to decrease attenuation to 0.5 dB/m on excitation wavelength. The experiments show that effluence efficiency correlates with thickness of depressed cover – the more is thickness of a cover, the less are losses. The basic technology of perforated fiber light guides creation from quartz glass with four cycles of the openings, based on twophase process was developed. Unlike perforated light guides with a single-element core in the developed systems with equal diameters of a core the step of structures is two and three times less. It gives the possibility to receive big resistance of radiation to indignations of a light-guide path. At a problem definition of receiving the microstructured fiber with small value of the relation of an opening diameter of a constructional cover to a step of structure and/or with rather small step of structure single-stage process as in this case in initial assembly it is possible to use capillaries with small size internal diameter. Researches were conducted to search technological conditions for minimum attenuation of a certain type radiation in the microstructured light guides. The main way to receive answers about influence of the technological scheme on radiation attenuation is comparison of one - and two-phase methods of microstructured light guides creation. Dependence of radiation losses in light guides from temperature of capillaries extract was defined. Comparison of capillaries cleaning methods in perforated light guides is carried out. Methods of radiation attenuation decrease are offered.
MULTI-ZONE ANTIREFLECTION COATING ON A SUBSTRATE MADE OF OPTICAL ZINC SULPHIDE Tan Tai Do, Gubanova Lyudmila Alexandrovna
The paper deals with creation technique for a multi-zone antireflection coating on a substrate made of the optical zinc sulphide ZnS. The coating effectively operates simultaneously in the following spectral ranges: visible region of 450 - 700 nm, in the near infrared region of 1000 - 1100 nm, at the wavelength of 1.55 μm, and in the mid-infrared (IR) spectrum of 3 - 5 microns. Reflection coefficient in the range of 450 - 700 nm is not more than 2%, in the range of 1000 - 1100 nm is less than 0.5%, in the range of 1500 - 1700 nm is close to 1.5% and in the range of 3 - 5 μm is equal to 0.6%. Analysis results of the deviation impact in the thickness of layers on the value changing of the energy reflection coefficient in the considered areas are given. Deviation in the thickness of the layer, contiguous with the air, is shown to have the greatest effect on the spectral characteristics of the obtained coating. Refractive index deviation for this layer influences the magnitude of the residual reflection.
The paper deals with the precision control for the parameters of manufactured paper production, such as various kinds of paper and photo paper for printing. Research of untreated, matte, glossy and laminated paper is conducted by atomic force microscopy by means of educational and scientific scanning probe microscope NanoEducator LE in the framework of this paper. Visualization of characteristic structure for each type of studied paper was conducted, histogram of roughness was obtained, and average roughness of height differences was defined. A laminated paper has got the lowest roughness (Ra of about 70 nm) and glossy paper has got Ra of about 170 nm; roughness of untreated paper with cellulose fibers is about 530-540 nm, and matte paper has got the highest roughness parameters (Ra about 670-680 nm). Scanning probe microscopy application for parameters monitoring of cellulosic paper production is shown to give the possibility of such microscopy type application in the production of paper products and high-precision control of its parameters.
ENERGY-SAVING TECHNOLOGY OF CHEMICAL AGENTS MELTING BY LIGHT RADIATION Cherepanov Arkady N
The paper deals with new melting technology of chemical agents with antireflection liquid phase by means of light radiation. A method of melting is proposed, based on the light radiation effect. Emitter design based on halogen lamps is developed and used as a nozzle to the contact heater. The lamps are placed into individual transparent cases which gives the possibility to align the temperature distribution on the emitter surface and avoid excessive heat of the lamps. Such emitters were used for melting of synthetic fatty acids used in the production of detergents. Previously developed calculating methods for the melting process velocity of the combined influence of light radiation and thermal power released on the surface of the transparent case on the melting agents are used in the process of emitter designing. The number of emitters and the distance between them are determined in view of calculations and data of light and thermal characteristics of emitters. Experimental verification showed the possibility of channel depth melting equal to 1 m in 5-6 hours. This is three times less than it is necessary for channel melting by contact heater. At the same time energy consumption is increased only by 7 % as compared with that one of the contact heater. Furthermore, the channel melted down has got a diameter larger than by using only a contact heater.
TECHNOLOGICAL IMPERFECTIONS OF FORCE ROD GEOMETRICAL PARAMETERS FOR PANDA OPTICAL FIBERS PRODUCTION Nikita Semenov, Nikolai Trufanov, Anatoly Adamov
The paper deals with the dependence in radial dimensions changes of the workpieces on the angular coordinate based on experimental data about the geometry of the cross-sections of force rods batch for the production of anisotropic Panda-type optical fibers. An algorithm of geometrical parameters statistical processing is described, which gives the possibility to find the similarity in the geometry of the cross-sections of different force rods, and reveal the characteristic shape of the crosssection for all the samples. The algorithm contains the shift of points for dependence changes in radial dimensions of the workpieces on the angular coordinate in order to find curves with maximum correlation coefficient. Afterwards, the distribution of the radius values for each angular coordinate is found basing on the obtained curves. It is demonstrated that in case of the force rods production with variable amount of alloying dopes on the radius via the MCVD method, it is impossible to get ideally round shape of the cross-section. At the same time, the biggest deviation from the round profile (up to 10%) is fixed on the border between the alloyed core of the force rod and the external layer of the pure quartz, whereas the deviations on other borderlines are negligible (a tenth hundredth of a percent). It is determined that within this technological process the non-circular cross-sectional shape of alloyed core is realized, which can be called “faceting” for convenience (with three “faces” of different length). The following long control of the cross-sectional shape of the force rods has proved the results recurrence.
VERIFICATION OF PARALLEL AUTOMATA-BASED PROGRAMS Michael Lukin
The paper deals with an interactive method of automatic verification for parallel automata-based programs. The hierarchical state machines can be implemented in different threads and can interact with each other. Verification is done by means of Spin tool and includes automatic Promela model construction, conversion of LTL-formula to Spin format and counterexamples in terms of automata. Interactive verification gives the possibility to decrease verification time and increase the maximum size of verifiable programs. Considered method supports verification of the parallel system for hierarchical automata that interact with each other through messages and shared variables. The feature of automaton model is that each state machine is considered as a new data type and can have an arbitrary bounded number of instances. Each state machine in the system can run a different state machine in a new thread or have nested state machine. This method was implemented in the developed Stater tool. Stater shows correct operation for all test cases.
DATA ANALYSIS BY SQL-MAPREDUCE PLATFORM Dergachev Alexander A
The paper deals with the problems related to the usage of relational database management system (RDBMS), mainly in the analysis of large data content, including data analysis based on web services in the Internet. A solution of these problems can be represented as a web-oriented distributed system of the data analysis with the processor of service requests as an executive kernel. The functions of such system are similar to the functions of relational DBMS, only with the usage of web services. The processor of service requests is responsible for planning of data analysis web services calls and their execution. The efficiency of such web-oriented system depends on the efficiency of web services calls plan and their program implementation where the basic element is the facilities of analyzed data storage – relational DBMS. The main attention is given to extension of functionality of relational DBMS for the analysis of large data content, in particular, the perspective estimation of web services data analysis implementation on the basis of SQL/MapReduce platform. With a view of obtaining this result, analytical task was chosen as an application-oriented part, typical for data analysis in various social networks and web portals, based on data analysis of users’ attendance. In the practical part of this research the algorithm for planning of web services calls was implemented for application-oriented task solution. SQL/MapReduce platform efficiency is confirmed by experimental results that show the opportunity of effective application for data analysis web services.
ON THE EFFECT OF ADAPTIVE USER INTERFACES ON RELIABILITY AND EFFICIENCY OF THE AUTOMATED SYSTEMS Yurii Furtat
In modern automated systems users often have to face the information overload problem because of ever increasing volumes of information with short time processing requirements. Working in such conditions affects the system operator’s work quality and the systems reliability. One possible approach to solving the information overload problem is to create personalized interfaces that take into account the user’s information management particularities. System operator’s features, which determine the shape and pace of information representation preferred by him, form the user’s cognitive portrait. To determine the values of portrait characteristics professional testing with the assistance of psychologists or operational testing at the user’s workplace is performed. The second option is more preferable for use in automated systems, since it has no issue with lack of psychologists. Cognitive portrait is then built as a result of user interaction with the software diagnostic tools that are based on the cognitive psychology methods. The effect of personalized user interface application in an automated system can be estimated by quantifying how the reduction in user’s response time to critical events affects the system reliability and efficiency. For this purpose, the formulae of reliability theory for complex automated systems are used, showing the dependence between the system reliability and user’s response time to critical event.
TASKS MAPPING METHOD FOR COARSE GRAIN RECONFIGURABLE SYSTEMS Alexander Rumyantsev
This paper deals with analysis of existing approaches to tasks mapping on reconfigurable computing systems with special attention paid to mapping methods for coarse grained reconfigurable computing systems. The purpose and objectives of a new heuristic method for tasks mapping on coarse grained reconfigurable computing systems are produced on the base of the carried out analysis. This novel method for tasks mapping on coarse grained reconfigurable computing systems is based on the method of graph partitioning with pushing vertices, graph covering algorithm, a heuristic approach to optimizing and packaging for a particular graph on coarse grained reconfigurable computing system and displaying methods of data flow graph on resources of coarse grained reconfigurable computing system. The simulation was conducted on system model with coarse grained reconfigurable hardware accelerator MATRIX. Experimental results are given. They prove the effectiveness of the proposed approach as compared with the widely used methods for tasks mapping on coarse grained reconfigurable computing systems and the ability to use dynamic functional parameters of coarse grained reconfigurable computing system to further improvement of the mapping results.
IRI-2012 MODEL ADAPTABILITY ESTIMATION FOR AUTOMATED PROCESSING OF VERTICAL SOUNDING IONOGRAMS Nikolaeva Vera D , Rybakov Michael V , Kotikov Andrey L, Koshelevsky Vladimir K
The paper deals with possibility of IRI-2012 global empirical model applying to the vertical sounding of the ionosphere semiautomatic data processing. Main ionosphere characteristics from vertical sounding data at IZMIRAN Voeikovo station in February 2013 were compared with IRI-2012 model calculation results. 2688 model values and 1866 real values of f0F2, f0E, hmF2, hmE were processed. E and F2 layers critical frequency (f0E, f0F2) and the maximum altitudes (hmF2, hmE) were determined from the ionograms. Vertical profiles of the electron concentration were restored with IRI-2012 model by measured frequency and height. The model calculation was also made without the inclusion of the real vertical sounding data. Monthly averages and standard deviations (σ) for the parameters f0F2, f0E, hmF2, hmE for each hour of the day were calculated according to the vertical sounding and model values. Model applicability conditions for automated processing of ionograms for subauroral ionosphere were determined. Initial IRI-2012 model can be applied in the sub-auroral ionograms processing at daytime with undisturbed conditions in the absence of sporadic ionization. In this case model calculations can be adjusted by the near-time vertical sounding data. IRI-2012 model values for f0E (in daytime) and hmF2 can be applied to reduce computational costs in the systems of automatic parameters search and preliminary determination of the searching area range for the main parameters. IRI-2012 model can be used for a more accurate approximation of the real data series in the absence of the real values. In view of sporadic ionization, ionosphere models of the high latitudes must be applied with corpuscular ions formation unit.
ACCURACY EVALUATION OF THE OBJECT LOCATION VISUALIZATION FOR GEO-INFORMATION AND DISPLAY SYSTEMS OF MANNED AIRCRAFTS NAVIGATION COMPLEXES Kostishin Maksim O. , Zharinov Igor Olegovich, Zharinov Oleg O, Nechaev Vladimir A., Suslov Vladimir D
The paper deals with the issue of accuracy estimating for the object location display in the geographic information systems and display systems of manned aircrafts navigation complexes. Application features of liquid crystal screens with a different number of vertical and horizontal pixels are considered at displaying of geographic information data on different scales. Estimation display of navigation parameters values on board the aircraft is done in two ways: a numeric value is directly displayed on the screen of multi-color indicator, and a silhouette of the object is formed on the screen on a substrate background, which is a graphical representation of area map in the flight zone. Various scales of area digital map display currently used in the aviation industry have been considered. Calculation results of one pixel scale interval, depending on the specifications of liquid crystal screen and zoom of the map display area on the multifunction digital display, are given. The paper contains experimental results of the accuracy evaluation for area position display of the aircraft based on the data from the satellite navigation system and inertial navigation system, obtained during the flight program run of the real object. On the basis of these calculations a family of graphs was created for precision error display of the object reference point position using the onboard indicators with liquid crystal screen with different screen resolutions (6 "×8", 7.2 "×9.6", 9"×12") for two map display scales (1:0 , 25 km, 1-2 km). These dependency graphs can be used both to assess the error value of object area position display in existing navigation systems and to calculate the error value in upgrading facilities.
DETECTION OF BACTERIA IN FOODSTUFF BY MACHINE LEARNING METHODS Alexey Saenko, Musalimov Victor M, Steffen Lerm, Gerhard Linss
The paper deals with an actual problem of ensuring the control of foodstuff quality by means of machine learning methods. Existing analysis methods require special laboratory environment, significant time and depend on the qualification and some physiological characteristics of an expert while the suggested method gives the possibility to decrease significantly the costs due to automatization. The mobile analysis platform performing this method is based on the fluorescence microscopy. The problem of the object classification as either “bacterium” or “third-party artifact” was solved for the test data with some classification algorithms as support vector machine, random forest, decision tree C4.5, k-nearest neighbors, Bayes method. The analysis showed that the most effective algorithms are support vector machine and random forest. This research is performed on the Mechatronics Department of Saint Petersburg National Research University of Information Technologies, Mechanics and Optics and the Quality Assurance and Industrial Image Processing Department of Ilmenau University of Technology with the support of the program “Mikhail Lomonosov” of the Ministry of Education and Science of Russia and the German Academic Exchange Service.
DOCUMENT REPRESENTATION FOR CLUSTERING OF SCIENTIFIC ABSTRACTS Popova Svetlana V, Danilova Vera V
The key issue of the present paper is clustering of narrow-domain short texts, such as scientific abstracts. The work is based on the observations made when improving the performance of key phrase extraction algorithm. An extended stop-words list was used that was built automatically for the purposes of key phrase extraction and gave the possibility for a considerable quality enhancement of the phrases extracted from scientific publications. A description of the stop- words list creation procedure is given. The main objective is to investigate the possibilities to increase the performance and/or speed of clustering by the above-mentioned list of stop-words as well as information about lexeme parts of speech. In the latter case a vocabulary is applied for the document representation, which contains not all the words that occurred in the collection, but only nouns and adjectives or their sequences encountered in the documents. Two base clustering algorithms are applied: k-means and hierarchical clustering (average agglomerative method). The results show that the use of an extended stop-words list and adjective-noun document representation makes it possible to improve the performance and speed of k-means clustering. In a similar case for average agglomerative method a decline in performance quality may be observed. It is shown that the use of adjective-noun sequences for document representation lowers the clustering quality for both algorithms and can be justified only when a considerable reduction of feature space dimensionality is necessary.
USAGE OF BC7 CONTAINER FOR STORING TEXTURES WITH 10-BIT COLOR DEPTH Ilya Perminov, Timоur Paltashev
High color depth images can more accurately reproduce colors and smooth color transitions without banding artifacts, especially for wide color gamut devices. The paper deals with texture compression with 10-bit color depth applied in 3D graphics. A method for storing of such textures in standard BC7 blocks is proposed. The example of BC7 block applicable for storing of smooth texture information with an accuracy exceeding 8-bit is also given. The proposed approach has a backward compatibility with current hardware. Additional hardware cost to support 10-bit decoding is expected to be low. An overview of developed software for compressor based on bc7_gpu is given. Comparison of PSNR and RMSE shows that the proposed compressor provides better quality for 10-bit textures; compressing errors become less for images with high color depth.
PRELIMINARY AND SUBSEQUENT FILTERING OF NOISE IN IMAGE RESTORATION ALGORITHMS Sizikov Valery S , Roman A. Exemplyarov
The paper deals with noising of smeared or/and defocused images. The sequence of the noise filtering on such images is stated before elimination of the smearing/defocusing or after it. The concepts of preliminary and subsequent filtering of noise are brought in. The smearing/defocusing of a series of images is eliminated by the methods of parametric Wiener filtering and Tikhonov regularization, while the noise is filtered out by the methods of median Tuckey filtering and adaptive Wiener filtering. These questions are considered by carrying out experimental testing with obtaining numerical estimates of image restoration errors for different noise types and sequence of their filtering on representative samples. The methods of parametric Wiener filtering and Tikhonov regularization are shown to eliminate the smearing/defocusing effectively enough but noise filtering is not effective. Effectiveness of noise filtering is raised by adding such methods as the median Tuckey filter, the adaptive Wiener filter. Furthermore, an order (sequence) of filtering is important for impulse noise (before or after elimination of the smearing/defocusing depending on noise-signal situation), and for Gaussian noise the order is unessential. It is shown that an impulse noise is filtered better by the median, order, adaptive median filtering, and the Gaussian noise - by adaptive Wiener filtering, average filtering. An explanation for these effects is given.
RELIABILITY ESTIMATION FOR SCREEN REPRODUCTION OF SATURATED PIGMENTS Lyubov Сherevan, Тозик В. Т.
The paper deals with the ability of modern display monitors to reproduce full color range of classical oil paintings. The models of the standard color gamuts of modern monitors are represented by visualization in CIELab color coordinate system. Pure mineral pigments are proved to be more saturated than oil colors. Therefore, reproduction ability of pure saturated pigments ensures the full range reproduction of oil colors. 75 color coordinates of pure pigments are obtained by means of the spectrophotometry method. The measured coordinates displacement is shown as compared with the color gamuts of standard monitors. The quantitative method of reliability estimation for the reproducing of full color ranges of classical oil paintings is developed. The method consists of color differences calculating for out-of-gamut colors (measuring that of the reference coordinate against the closest one inside the gamut) and comparing the results with the standard threshold color difference. It is proved that sRGB monitor does not represent effectively the full color range of classical oil paintings, and AdobeRGB monitor reproduces satisfactorily the full range of colors (with the difference below the threshold of human perception). Developed quantitative method can be applied for any kind of monitor estimation.
OPERATIONAL CHARACTERISTICS OF INFORMATION SYSTEM SECURITY THREATS RISK Shcheglov Konstantin A, Shcheglov Andrey Yu
The paper deals with widely used methods for effectiveness evolution and information systems security tools development. Their general disadvantage that consists in not giving the possibility to consider security threats as information system operational characteristic is revealed. Therefore, an adequate information system model can’t be created, including secure information system like system with failure and recovery parameters, characterized by threats appearing and elimination during system operation. Also it doesn’t make it possible to identify appropriate relationship (including time ones), between threats and their exploited aggregates and doesn’t give the possibility to introduce quantitative measures of the threats relevance and attacks effectiveness (like system operational characteristic). Consequently, it doesn’t make it possible to estimate the level of information system operational security and security tools effectiveness. The principles of operational security theory are suggested, base operational parameters and characteristics are introduced, a method for operational characteristics of information system estimation is proposed, operational characteristics of risks for information system security threats and loss risks are stated.
ANONYMOUS WEBSITE USER IDENTIFICATION BASED ON COMBINED FEATURE SET (WRITING STYLE AND TECHNICAL FEATURES) Vorobeva Alisa A. , Aleksey Gvozdev
The task of anonymous web users identification becomes more and more important research task. The number of users is increased dramatically and usage of the Internet for criminal purposes (such as anonymous threats and extremist statements) becomes more frequent. Existing approaches and algorithms for identifying anonymous users are not enough efficient. In the context of this work, user identification means recognizing of an anonymous user on the Internet. Identification is performed by correlating the set of anonymous user features with stored in the database features collected previously. Feature set of the user consists of technical features (IP- address, OS version, etc.) and writing-style features of the user (for short texts in the Russian language). We compared the discriminating power of three feature sets (technical, writing-style and combined) and of three classification methods (Support Vector Machines, neural networks, logistic regression). Results of the experiment showed that the usage of combined feature set (writing-style and technical features) improves the identification accuracy of an anonymous user of the Internet.
ENGINEERING AND TECHNOLOGIES
CALCULATION METHODS FOR IRRADIANCE COEFFICIENTS OF CYLINDRICAL SPACE OBJECT BY THE EARTH RADIATION Dzitoev Azamat M., Khankov S.I.
The paper deals with approximate calculation methods for effective irradiance coefficients of cylindrical form space object typical for external cases of space telescopes and fragments of spacecrafts as well. There are no analytical calculation methods nowadays for integrated and effective irradiance coefficients for space objects of such configuration. Integrated irradiance coefficients define the average thermal balance on a cylindrical surface and effective ones – all over the cylinder surface taking into account its butt ends. Calculations of effective coefficients for space objects irradiance by the Earth radiation are necessary for definition of the major component of power balance – the specific power of the Earth inherent thermal radiation. Such calculations are used for determination of average temperatures of space objects. The technique is based on generalization and approximation of results for numerical calculations in the range of orbit height change from 200 km to 40000 km and also in all possible range of a tilt angle change of a cylinder axis. Uncertainties in mathematical model at small location deviations for cylinder axis from zenith-nadir line are shown. Errors of the approximate solution are analyzed during determination of integrated irradiance coefficient for a lateral cylindrical surface. The admissible total error of the received approximate solution was estimated at a temperature deviation of an object in the Earth shadow from its exact value. At the large ratios of the cylinder height to its diameter calculation, errors of integrated irradiance coefficient are maximum and can cause temperature error definitions in the Earth shadow up to 1,5 K. Errors of cylinder temperature calculation decrease with reduction of its height-to-diameter ratio. They have minimum values for a thin disk model. Temperatures calculation errors are considerably decreased for a case of cylindrical object location on the trajectory section illuminated by the Sun, and even more – at calculations of a non-stationary thermal mode. The offered calculation technique is rather accurate, simple and convenient for calculations.
OFF-LINE INTERACTION OF THE NONLINEAR DYNAMIC SYSTEMS Ivanov Sergey E, Gennady I Melnikov
Mathematical model of many mechanical systems is the system of dynamic equations with polynomial structure and periodic or constant parameters. Such mechanical systems are widely applied in the dynamics of a vibration guard of devices. Research of nonlinear systems with a finite number of freedom degrees represents a complicated actual problem in comparison with linear systems. Research of nonlinear systems does not come to definition of a finite number of private solutions because nonlinear systems do not possess superposition property of solutions. Mathematical model of nonlinear dynamic system with three degrees of freedom which contains polynomials to the fourth degree from phase variables is considered. Algorithmic formulas of an off-line interaction method of nonlinear dynamic systems are presented for the given model research. The nonlinear mathematical model of dynamic system is transformed to the autonomous form, and principal parameters of dynamic system are defined. The algorithm of an off-line interaction for research of nonlinear system protected from vibrations with three degrees of freedom is presented. In case of vibration guard solution of problems linear systems are widely used though linearity of functions does not approximate precisely enough the system performance, causing analysis errors. The problem of deriving and research of more exact nonlinear system model protected from vibrations is solved. The nonlinear system protected from vibrations with three degrees of freedom and nonlinear right members in the form of a polynomial of the third degree from phase variables with constant and periodic parameters is considered. The system consists of a vibration guard plant established on two platforms, one under another, the lower one is put on the vibrating foundation. Exterior harmonious perturbation exerts influence upon the foundation. Elastic system elements are supposed to be described by polynomials of the third degree and damping elements have nonlinear cubic performance. As a result of method application the nonlinear system will be transformed to the more simple autonomous form and the amount of parameters of nonlinear dynamic system is essentially reduced. The autonomous system contains essentially less parameters, than initial system, without making worse solution quality. Method application simplifies essentially the research of transitive and settled processes of nonlinear dynamic systems. The solved research problem for the system protected from vibrations in nonlinear statement is new and has theoretical and practical value.
MODERN STATE AND DEVELOPMENT PROSPECTS OF THE BASIC CONCEPTS IN THE FIELD OF MECHATRONICS Shalobaev Evgeniy Vasilievich, Toločka Rimantas T
The paper deals with modern state analysis of the basic terms in the field of mechatronics documented by the Commission on standardization and terminology of the International Federation for the Theory of Machines and Mechanisms. New terms introduced into scientific circulation since the beginning of the 21st century are indicated. They are: “mechatronized object”, “mechatronic class”, combined “mechatronic” and “mechatronized” objects. The notion of “tiered approach” to mechatronics is given, which makes it possible to connect the mechatronics proper, micro-system technique and nanotechnologies. Some considerations on the use of “mechatronic complex” term are stated especially topical in the implementation process for the groups of small spacecrafts. That is why the term “mechatronic complex” is filled with real content. Such criteria, characteristic of mechatronic objects, as maintainability and durability are amended. Corrections to the “mechatronic modules” term application are proposed. The question is raised on the necessity to expand the mechatronics meaning from the movement computer management to object state control and to define such terms as “avionics” and “autonics”. Moreover, interconnection between mechatronics and logistics, which is now referred to the subject field of mechatronics, must be defined.
APPLICATION EXPERIENCE AND PROSPECTS OF DIAMOND MICRO-TURNING TECHNOLOGY Medunetskiy Viktor M., Sergey V. Solk
The paper deals with application and further progress of diamond micro-turning technology (DT) based on the experience obtained in S&R Institute for Optoelectronic Instrument Engineering and compiled from literary sources. It is pointed out that the diamond turning technology is nowadays mainly used for shaping of the optical elements (OE) working surfaces, manufacturing of kinoforms, elements of fine mechanics and decorative processing. New DT applications are: shaping of the die mold working surfaces, combined technologies, making it possible to combine the shaping technologies and assembling of the optical mechanical systems (OMS), research into technological hereditary, consisting in studies of the surface diffraction structure machined by diamond turning, shaping of the OE working surfaces with astigmatism of the desired value and direction being used in the deeply cooled OMS. Perspective lines of DT development are given, such as production of machines based on the new kinematic schemes, chemical and electrochemical polishing of the OE working surfaces after DT with the aim to decrease roughness and to make irregular relief in visible and near-infrared spectral ranges, development of DT technologies for creation of new materials and improvement of the known technologies taking into account the concepts about the state of the surface layer, creation of regular nanorelief for generation of the surface electromagnetic waves to provide the surface properties control.
STRAIGHT COGS FORMATION FEATURES FOR CYLINDRICAL SPUR GEARS BY STEPPED GEAR-SHAPED CUTTERRasulov Nariman M, Humbat Guseynov, Ugurlu Nadirov
MATHEMATICAL AND COMPUTER SIMULATION
TEMPERATURE DEPENDENCE CONSIDERATION ISSUE FOR COEFFICIENT OF VOLUMETRIC HEAT CAPACITY IN SIMULATION OF LASER-ARC PAD WELD PROCESS Svyatoslav Lukyanenko, Valery Tretyak
The paper deals with research of steels and alloys melting and crystallization on the example of temperature field dynamics simulation for the laser-arc pad weld of composite materials. Mathematical model is one of the Stefan problems for nonlinear transient three-dimensional Fourier equation of heat conduction with boundary conditions. The problem is solved by the finitedifference method with the pass-through calculation scheme. Nonlinearity of the problem is caused by the temperature dependency of the volumetric heat capacity coefficient that has a peak in the interval of phase transition (melting – crystallization). The linear-exponential approximation method is offered to consider this dependence. At some nodes of the discrete mesh the temperature changes from solid phase range to liquid phase at one time step on account of high heat velocity. The algorithm of temperature dependence consideration for volumetric heat capacity peak in the interval of melting – crystallization is suggested based on the nested mesh idea. Though the computational complexity is increased by suggested algorithm it provides more accurate solution and ensures account of phase transition phenomenon. Calculation results for linear and linear-exponential approximation of temperature dependence for volumetric heat capacity are compared. It is shown that in case of linear-exponential approximation the solution process on dynamic adaptive mesh is speeded up due to decreasing of time steps number.
METHODS OF TEMPERATURE FIELD MODELING FOR CONTACTLESS LASER DEFORMATION OF A PLATE Svyatoslav Lukyanenko, Irina Mykhailova
Contactless laser deformation is a process of changing a geometrical form of an object by its heating and cooling without using mechanical forces. One of the factors, influencing deformation, is heating, which creates temperature field and overpatching speed of temperature field. The article deals with a computer modeling result for temperature field of a plate irradiated by a moving laser beam. Comparison of results, obtained by using two mathematical models and experiments, is conducted. Such parameters as density, thermal capacity and thermal conductivity are constant values in the first model, and they are linearly dependent on temperature in the second one. Linear approximation of table values by least-squares method is used to define this dependence. Both models have the temperature field computed by 3D non-stationary heat equation: it is linear function in first model and quasilinear function in the second. To solve the equation a six- step implicit finite difference coordinate-wise splitting scheme is applied, which has the second order of accuracy for all coordinates. Systems of linear algebraic equations, created by this finite difference scheme, are solved by modified Gauss method. Adaptive method is used for automatic design of variable difference mesh. It condenses nodes in high gradient zones and dilutes them in regions where temperature changes gradually. This gives the possibility for computation time shortening and receiving a result with predefined accuracy. Results of computer modeling show that taking into account dependence of material parameters on temperature produces more accurate results. However, it requires more steps and therefore it is more time-consuming.
DETACHED-EDDY SIMULATION OF TURBULENT AIRFLOW Voronin Aleksei A, Lukyanov Gennadiy N, Frolov Evgeny V
A brief survey of the most significant mathematical models of the air and fluid flows from Prandtl’s mixing length layer theory to RANS models with one and two differential equations, as well as unsteady LES and DES models is given. Detachededdy simulation was first proposed by P.Spalart in 1997 and combined the main advantages of LES and RANS methods which gave the researchers the possibility to widen the sphere of such models application. The authors give the basic mathematical description of DES models paying special attention to the most important differences between DES and RANS models. The 3D geometrical model of human nasal cavities obtained from computer-aided tomography data using Mercury Amira program is also given. The 3D unstructured mesh with 1,5×107 finite elements was constructed after the segmentation using Altair Hypermesh software had been finished. The mesh was used to set up an unsteady simulation of airflow inside the obtained geometrical model. Application of DES method on the mesh of а good quality made it possible to distinguish the small-scale turbulent swirls inside the flow. A solid-state model of human nasal cavities for experimental investigation of the breathing process was designed. The measured values of the pressure drops inside the model during breathing simulation showed good correlation with results obtained from the numerical calculations using Ansys software. The conclusion was made that DES models may be used for flows simulation of liquids and gases in non-regular shaped channels.
MARKET-MAKING STRATEGY IN THE SYSTEM OF ALGORITHMIC HIGH-FREQUENCY TRADING Toropov Alexander V
Market maker is the most important participant of modern exchange trading, it provides the increase of market liquidity and reduces the difference between bid and ask (spread). The paper presents automatic market-making strategy for quoting of options and other kinds of financial instruments on electronic markets. Quotes are based on theoretical pricing which is a resource-intensive task. Presented algorithmic optimizations, in particular quotes caching and smoothing of underlying asset price oscillation, give the possibility up to four times boost for quote modify scenario on real market data. Mechanism of quotes caching precalculates quotes in certain diapason around current underlying price. If underlying price changes within the diapason, algorithm sends already filled message for quote modification, instead of new complex computation. Smoothing of underlying asset price oscillation prevents permanent moving of the diapason and reacts only on significant market moving. A size of caching diapason which provides optimal correlation between speed of quotes modification and resource consumption has been defined experimentally (40 elements). In case of quoting 36 options on Eurex Exchange an average delay between underlying price change and quote modification is 277 usec. The measurements were carried out on the Sun X4170 M3: CPU(s): 2xXeon 2.9GHz RAM: 128 GB server under Solaris 10 operating system. Obtained results correspond to modern market-making requirements. The developed strategy is used by big European banks and trading firms.
INFORMATION TECHNOLOGIES IN EDUCATION
FROM TRADITIONAL DISTANCE LEARNING TO MASS ONLINE OPEN COURSES Vladimir N. Vasiliev, Stafeev Sergey K., Liubov S. Lysitsina, Olshevskaya Anastasiya V
The issue of transition for higher education institutions of Russia from traditional distance learning to mass electronic education on the basis of the online open courses is considered, its relevance is proved. Analysis of the major prerequisites for transition success is carried out (a demand for the educational Internet resources from mobile devices; existence of a large number of various electronic resources which are successfully used in practice by higher education institutions in remote educational technologies; maintaining experience for electronic magazines of students’ progress for planning and estimation of training results; essential growth of material costs in the world online training market). Key issues of transition are defined and the basic principles of electronic online courses development are formulated. A technique for electronic online course development aimed at the result is given. The technique contains the following four stages: planning of expected training results, course electronic content structuring and training scenarios creation, development of the tests plan and electronic estimated means for automatic control of the planned training results; course realization by means of game mechanics and technologies of network communication between students. Requirements to various forms of control planned in the course of learning results are defined. Two kinds of electronic online courses are assigned (knowledge-intensive and technological courses). Examples of their realization in the authors’ online courses "Wave Optics", "Theory of Graphs ", "Development of Web Interfaces on the Basis of HTML and CSS" created and practically used in NRU ITMO in 2013 are given. Finally, the actual tasks of mass open education development in the leading higher education institutions of Russia are set forth.
ОБРАТИМАЯ ФОТОДЕСТРУКЦИЯ НАНОЧАСТИЦ СЕРЕБРА В ФОТО-ТЕРМО-РЕФРАКТИВНЫХ СТЕКЛАХ Ignatiev Dmitriy A, Ignatiev Alexander I , Nikonorov Nikolay V. , Starodubov Dmitry Sergeeivich
Исследован процесс фотодеструкции наночастиц серебра в фото-термо-рефрактивных стеклах. Показано, что при облучении импульсным лазером в фото-термо-рефрактивных стеклах происходит фотофрагментация и фотоионизация наночастиц серебра. Последующая термообработка приводит к росту наночастиц серебра, что говорит об обратимости процесса фотодеструкции наночастиц серебра.
EQUATIONS OF RADIATION TRANSFER IN INFRARED TOMOGRAPHY IN THE CASE OF ACTIVE-PASSIVE DIAGNOSIS AND SWEEPING SCANNING Alena Makarova
Sweeping scanning scheme of a hot gas in the task of infrared tomography is formulated. Two diagnosis regimes are used: the active one (ON) – with included source and the passive one (OFF) – without it. Two integral equations are deduced concerning the absorption coefficient k and the Planck function B of a medium (by which it is possible to calculate the temperature profile of a medium T).
REAL TIME REGISTRATION OF THE ELECTROPHYSIOLOGICAL SIGNALS SPECTRA Dmitriy Tolkovich, Evgenia Andrianova
The paper deals with the issues of spectra acquisition for the electrophysiological signals, diagnostics result dependence on the noise level and expert’s qualification. A real-time module for amplitude-frequency spectra estimation of electrophysiological signals is designed. A general diagram of connection between measuring module and spectrum analyzer (as a part of multifunctional diagnostic system) is shown. The module is realized on the base of Cubieboard A20 minicomputer. It provides continuous decomposition of signals (up to 32 channels) into fragments of equal length and their independent mathematical processing for each measuring channel. The suggested device makes it possible to analyze the real-time dynamics of spectrum changes.