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## Publications

## Editor-in-Chief

**Nikiforov**

Vladimir O.

D.Sc., Prof.

Vladimir O.

D.Sc., Prof.

## Partners

**Summaries of the Issue**

### REVIEW

PHOTONICS AND OPTICAL INFORMATICS IN EUROPE: TRENDS OF 2003–2013
Stafeev Sergey K., Livshits Irina Leonidovna, Olshevskaya Anastasiya V, Veronica A. Zhogina, Ekaterina A. Denisova, Markina Galina L, Paul Urbach H.

1

Retrospective structure analysis of the European scientific and technological platforms – photonics, nanomaterials and photovoltaics – is represented from the point of view of their structure, interpenetration of subjects and dynamics of the changes which have occurred over the last ten years. Geoinformation component of the European optical education is analyzed. Criteria of research and the ontological models, giving the possibility to reveal correlations between development of scientific researches and industrial applications, on the one hand, and dynamics of educational programs on optics, photonics and optical informatics are described. Data on quantitative and high-quality changes in educational programs and appropriate academic degrees on the corresponding training directions are submitted. The material is illustrated with fragments of the associative card "Modern Directions of Researches in the Field of Optics, Photonics and Optical Information" and the conceptual card "European Scientific and Technological Platforms". The tag cloud is given in lower ontological level for two concrete subject domains of "Lasers" and "Optics Communications". Convergent and divergent trends, characteristic for the last decade development of optics, photonics and optical informatics in Europe are formulated. The main trends are: the directions and rates of the market development correlate with geoinformation data on the European scientific and educational tendencies; telecommunications and information technologies are dominating spheres of knowledge application and competences of the European experts in optics, photonics and optical informatics; the ontological structure of knowledge bases in the field of biophotonics, polymeric optics, photon crystals and "clever" optical metamaterials becomes more branched; a number of conceptual ontological knots in optics, photonics and optical informatics are gradually losing their relevance, being replaced by new concepts or the whole ontological branches.

### PHOTONICS AND OPTOINFORMATICS

TWO-DIMENSIONAL LOCALIZATION OF ATOMIC POPULATIONS IN FOUR-LEVEL QUANTUM SYSTEMS
Ekaterina A. Efremova, Maxim Yu. Gordeev, Yuri V. Rozhdestvensky

12

The paper deals with investigation of one aspect of fundamental problem of laser radiation interaction with the
matter. This problem is spatial localization of atomic populations due to fields impact of few running waves. We are the first to propose in our work two–dimensional spatial localization of atomic populations in medium with tripod–like configuration of levels under the field influence of running waves only. Three running waves, propagating along one plane 120o angle-wise to each other, form the system of standing waves in this plane. Atomic populations can be localized in the field of these standing waves. Moreover, the degree of such localization can make up hundredth parts of the wavelength of the incident optical radiation. It is shown that an excitation of the central transition of the tripod-like system using a field of multidirectional linearly polarized running waves is the necessary condition of the population dependence from spatial coordinates in the XY – plane. The two–dimensional shapes that appear in this system can have very complicated structure such as “double – craters”.

THE RECURRENT ALGORITHM FOR INTERFEROMETRIC SIGNALS PROCESSING BASED ON MULTI-CLOUD PREDICTION MODEL
Volynsky Maxim Alexandrovich, Gurov Igor P, Skakov Pavel Sergeevich

18

The paper deals with modification of the recurrent processing algorithm for discrete sequence of interferometric signal samples. The algorithm is based on subsequent reference signal prediction at specifying a set (“cloud”) of values for signal parameters vector by Monte Carlo method, comparison with the measured signal value and usage of the residual for enhancing the values of signal parameters at each discretization step. The concept of multi-cloud prediction model is used in the proposed modified algorithm. A set of normally distributed clouds is created with expectation values selected on the base of criterion of minimum residual between prediction and observation values. Experimental testing of the proposed method applied to estimation of fringe initial phase in the phase shifting interferometry has been conducted. The estimate variance of the signal reconstructed according to estimated initial phase from initial signal does not exceed 2% of the maximum signal value. It has been shown that the proposed algorithm application makes it possible to avoid the 2π-ambiguity and ensure sustainable recovery of interference fringes phase of a complicated type without involving a priori information about interference fringe phase distribution. The usage of the proposed algorithm applied to estimation of interferometric signals parameters gives the possibility for improving the filter stability with respect to influence of random noise and decreasing requirements for accuracy of a priori filtration parameters setting as compared with conventional (single-cloud) implementation of the sequential Monte Carlo method.

INVESTIGATION OF BIOLOGICAL OBJECTS IN OPTICAL COHERENCE TOMOGRAPHY WITH DATA PROCESSING BY SEQUENTIAL MONTE CARLO METHOD
Skakov Pavel Sergeevich, Volynsky Maxim Alexandrovich, Gurov Igor P, Ermolaev Petr A

23

A possibility of sequential Monte Carlo method application for data processing in the full-field optical coherent tomography for studying of biological objects is demonstrated. The suggested algorithm is based on statistical approximation of the estimated parameters instead of nonlinear functional transformations. Experimental results of data processing in the studies using full-field optical coherence tomography system based on the Linnik micro-interferometer are given with subsequent signals envelope estimation by sequential Monte Carlo method. It was established that the processing results contain fewer artifacts caused by instability of the algorithm as compared with the previously obtained results using the extended Kalman filtering. Processing of the full-field optical coherence tomography system data involving the sequential Monte Carlo method gave the possibility to observe an object microstructure with resolution of about 1 μm. Experimental testing of sequential Monte Carlo method was performed by analyzing the signals obtained in the study of the front wing of the common house mosquito Culex pipiens, because this object has a small size, low thickness and complicated microstructure and, therefore, is a convenient test object. These results are in a good agreement with observations obtained by conventional microscopy techniques and can be of interest for specialists in the field of entomology and bioengineering.

### OPTICAL ENGINEERING

AUTOMATIC CALIBRATION METHOD FOR STEREOSCOPIC SYSTEM
Korotaev Valery Viktorovich, Andrey V. Krasnyaschikh, Yaryshev Sergey Nikolaevich, Hoang Viet Nguyen

29

The paper deals with a new method of automatic calibration for stereoscopic system using test object. The idea of the method is to register stereoscopic image of specially selected reference object in the form of a chessboard with an extra field – a frame around chessboard – by means of two cameras. An algorithm implementing this method consists of seven stages: registration of set of images for a test object; image threshold filtering; recognition of test object by size and shape; background removal; position determination of four edge points; calibrating of the first and the second cameras; calibrating of stereoscopic system on the whole. The calibration process for the first and the second cameras and the system is performed by using a program developed by Jean-Yves Bouguet. Mathematical and physical modeling is done by means of two measuring cameras and MATLAB software package. Comparative error study for determination of the coordinates of test points in manual and automatic mode is carried out by modeling, as well as calibration error depending on the number of images obtained by stereo pair.

METHOD OF IMAGE QUALITY ENHANCEMENT FOR SPACE OBJECTS
Altukhov Alexander Ivanovich , Korshunov Denis S, Shabakov Evgeniy I

35

The paper deals with an approach for image quality improvement of the space objects in the visible range of
electromagnetic wave spectrum. The proposed method is based on the joint taking into account of both the motion velocity of the space supervisory apparatus and a space object observed in the near-earth space when the time of photo-detector exposure is chosen. The timing of exposure is carried out by light-signal characteristics, which determines the optimal value of the charge package formed in the charge-coupled device being irradiated. Thus, the parameters of onboard observation equipment can be selected, which provides space images suitable for interpretation. The linear resolving capacity is used as quality indicator for space images, giving a complete picture for the image contrast and geometric properties of the object on the photo. Observation scenario modeling of the space object, done by sputnik-inspector, has shown the possibility of increasing the linear resolution up to10% - 20% or up to 40% - 50% depending on the non-complanarity angle at the movement along orbits. The proposed approach to the increase of photographs quality provides getting sharp and highcontrast images of space objects by the optical-electronic equipment of the space-based remote sensing. The usage of these images makes it possible to detect in time the space technology failures, which are the result of its exploitation in the nearearth space. The proposed method can be also applied at the stage of space systems design for optical-electronic surveillance in computer models used for facilities assessment of the shooting equipment information tract.

### AUTOMATIC CONTROL AND ROBOTICS

ROBUST REGULATION FOR SYSTEMS WITH POLYNOMIAL NONLINEARITY APPLIED TO RAPID THERMAL PROCESSES
Kapitonov Alexander A, Aranovskiy Stanislav V., Ortega Romeo

41

Abstract. A problem of output robust control for a system with power nonlinearity is considered. The considered problem can be rewritten as a stabilization problem for a system with polynomial nonlinearity by introducing the error term. The problem of temperature regulation is considered as application; the rapid thermal processes in vapor deposition processing are studied. Modern industrial equipment uses complex sensors and control systems; these devices are not available for laboratory setups. The limited amount of available sensors and other technical restrictions for laboratory setups make it an actual problem to design simple low-order output control laws. The problem is solved by the consecutive compensator approach. The paper deals with a new type of restriction which is a combination of linear and power restrictions. It is shown that the polynomial nonlinearity satisfies this restriction. Asymptotical stability of the closed-loop system is proved by the Lyapunov functions approach for the considered nonlinear function; this contribution extends previously known results. Numerical simulation of the vapor deposition processing illustrates that the proposed approach results in zero-mean tracking error with standard deviation less than 1K.

### MATERIAL SCIENCE AND NANOTECHNOLOGIES

NANOSTRUCTURING AS A WAY FOR THERMOELECTRIC EFFICIENCY IMPROVEMENT
Lev P. Bulat, Leonid V. Bochkov, Irina A. Nefedova, Ahiska Rashit

48

The urgency of thermoelectric energy conversion is proved. Perspectives of nanostructures usage as thermoelectric materials are shown. The authors have systematized and generalized the methods and investigation results of bulk nanostructure thermoelectrics based on Bi-Sb-Te solid solutions. Ways of nanoparticles fabrication and their subsequent sintering into a bulk sample, results of structure study of the received materials are shown by methods of electronic microscopy and X-ray spectroscopy, results of mechanical properties investigation. Methods of manufacturing suggested with the authors’ participation and properties of thermoelectric nanocomposites, fabricated with addition of fullerene, thermally split graphite, graphene and molybdenum disulphide are discussed. Methods for prevention of recrystallization, measurement methods of thermoelectric properties of studied nanothermoelectrics are considered, including electric and thermal conductivities, thermoemf and the figure of merit. Factors that influence on thermoelectric figure of merit, including the tunneling of carriers through interfaces between nanograins, the additional phonon scattering on nanograin borders and the energy filtration of carriers through barriers have been theoretically investigated. Mechanisms and ways for improvement of the figure of merit are determined. Experimental confirmation for thermoelectric figure of merit increase is received. Physical mechanisms of thermoelectric figure of merit increase are shown by perceptivity of nanostructures utilization. The growth of thermoelectric figure of merit means an expansion of areas for rational application of thermoelectric energy generation and thermoelectric cooling.

SPECTRAL AND LUMINESCENT PROPERTIES OF CHROMIUM IONS IN FORSTERITE-LIKE NANO-GLASS CERAMICS
Vladimir A. Aseev, Sergei N. Zhukov, Nikolai V. Kuleshov, Sergei V. Kurilchik, Alexander V. Mudryi, Nikonorov Nikolay V. , Rokhmin Alexei S, Anatoly S. Yasyukevich

57

Comparative analysis of spectral and luminescent properties for glasses SiO2-Al2O3-MgO-K2O-TiO2 doped with chromium ions and forsterite nano-glass ceramic have been done. Initial glasses were obtained by using a conventional melt quenching method. Glass ceramics were produced by the two-stage secondary heat treatment of initial glasses. At the first step of the heat treatment nucleation centers were formed at 700º C. At the second step there was an increase of Mg2SiO4: Cr crystalline phase. Crystalline phase composition and the crystals size were determined by X-ray diffractometer. It is shown that the crystalline phase of Mg2SiO4 (forsterite) is precipitated during the heat treatment. Valency state and the chromium ion position in a forsterite or a glassy matrix are determined according to luminescence and absorption spectra. Identification of absorption and luminescence bands in initial and heat-treated samples is carried out. The dependence between spectral and luminescent properties of chromium and heat treatment modes is examined. The results demonstrate that ions of the trivalent and tetravalent chromium are transforming to the forsterite crystalline phase during the heat treatment, and a part of them remains in the glassy phase. Presented research results can be used for the development of glasses and nanoscale glassceramic for fiber tunable lasers and broadband optical amplifiers of a near infrared range which are used in information and telecommunication technologies.

SPECTRAL AND LUMINESCENT PROPERTIES OF FLUOROPHOSPHATE GLASSES DOPED WITH YTTERBIUM AND ERBIUM
Sofia V. Zaytseva, Vladimir A. Aseev, Kolobkova Elena V, Nikonorov Nikolay V.

62

Fluorophosphate glasses are among the most promising media for ytterbium erbium lasers. The following advantages of this glasses are low OH-content, simple glass synthesis process and the possibility for a relatively high dope concentration of rare-earth ions (up to 15 wt %). The paper deals with complex investigation of the spectral and luminescent properties of fluorophosphate glasses doped with different concentration of ytterbium and erbium ions. Glass compositions based on Ba(PO3)2-BaF2-СaF2-MgF2-AlF3-SrF2-YF3 with different erbium fluoride concentration (from 1 to 12.5 mol%) were synthesized by conventional high temperature method. Absorption cross-sections and Judd-Ofelt parameters were determined based on the measured absorption spectra data. Erbium ions luminescence was excited by titanium-sapphire laser at 975 nm. Stimulated emission cross section was calculated by McCumber method. Fuchtenbauer-Landenburg formula is used to calculate erbium ions radiation lifetime. Calculated integral values of the absorption cross section are greater than of conventional phosphate glasses and reach abs =1,37×10-18 cm-2 and em =1,39×10-18 cm-2. The maximum value of quantum yield was equal to 85% and was obtained for sample with the erbium concentration of 1×1020 cm-3. Increasing of erbium ion concentration from 1 to 12,9×1020 cm-2 results in reducing of quantum yield by 7%, due to the low content of hydroxyl groups in fluorophosphate glasses. These glasses are a promising material for lasers and amplifiers design operating at 1.5 μm wavelength.

PARAMETERS OPTIMIZATION OF METAL-DIELECTRIC NANOSTRUCTURES FOR SENSOR APPLICATIONS
Egorov Vladimir I, Ilya V. Zvyagin, Elena D. Karpenko, Dmitry A. Klyukin, Sidorov Alexander Ivanvich

We present calculation results of optical properties of silver nanoparticles with dielectric shell in relation to their applications in chemical and biosensors. Absorption cross-section calculation for spherical silver nanoparticles was performed by quasi static dipole approximation. It is shown that dielectric shell thickness equal to 2-3 nm and its refraction index equal to 1,5-1,75 are optimal. Calculation results were compared to experimental data. Experimental investigation of metal-dielectric nanostructures sensitivity to external refraction index was performed. Synthesis of silver nanoparticles with dielectric shell on glass surface was performed by nanosecond laser ablation method in near-surface glass layer at 1,06 μm wavelength (Solar LQ129). Synthesis of silver nanoparticles without a shell on the glass surface with silver ions was performed using thermal treatment in wet atmosphere. Spectrophotometer Cary 500 (Varyan) was used for spectral measurements. In case of laser ablation method application, external refraction index changes from 1 (the air) to 1,33 (water) and plasmon resonance band shift for 6 nm occurs. In case of another method application at the same conditions the registered shift was equal to 13 nm. However, in the latter case the particles can be easily removed from the substrate surface. Obtained results will be useful for developing chemical and biological sensors based on plasmon resonance band shift.

### COMPUTER SCIENCE

HLD-METHODOLOGY APPLICATION FOR RECONFIGURABLE EMBEDDED SYSTEMS DESIGN
Klyuchev Arkadiy O, Kustarev Pavel V , Timоur Paltashev, Platunov Alexey E

74

The paper deals with HLD-methodology for embedded systems design (High Level Design Methodology for Embedded Systems), created and developed by specialists of ITMO University and "LMT" Research and Production Company. The currency of this topic is caused by constant growth of architectural complexity of reconfigurable embedded computing systems, by the importance increase of system design issues. Application of HLD-methodology in a number of applied projects is shown. Its usage has raised architectural and micro-architectural design quality. The methodology is based on: architectural abstractions system; architectural model design process of the computing system independent of hardware-software realization; aspect model of the computing system design process; actualization model of computational process on the basis of unified translator concept. Practical application of the proposed HLD-methodology solves important design problems. Computational process components are distributed reasonably on various phases of system life cycle (design, execution). Space expansion of design decisions search is provided. Architecture synthesis is implemented on the basis of a generalizing view at configuration and programming mechanisms based on computational process actualization model. Possibility of late fixing for concrete way of architectural decisions realization is provided. Vertical architectural notations are applied. Embedded system properties are flexibly changed by means of configuration within the framework of the chosen design aspects subset. It gives the possibility to control resources expenses for various phases of system life cycle (design, manufacture, usage, support). The proposed design HLD-methodology considers reconfigurable embedded system, first of all, through the prism of its target computational process organization at the design, configuration and execution phases in a unified key. Developers have got possibility for effective distribution search of computational process elements on various phases. The methodology includes groups of abstractions for work with the computing system components and the computing system on the whole, with embedded system design process and architectural decisions metrics. Basic propositions of HLDmethodology suggested by the authors are given. A number of reconfigurable embedded systems developed with the usage of HLD-methodology elements is represented.

METHOD OF HIGH-QUALITY SPEECH SYNTHESIS WITH A SMALL DATABASE USAGE
Pavel Chistikov, Andrey O. Talanov, Dmitry S. Zakharov, Anna I. Solomennik

83

We propose an approach to synthesizing high-quality speech in view of a small initial speech database. A robust method for solving this problem is vital for voice restoration (recovery of the lost fragments of recordings based on available speech material of a well-known person, e.g. an actor). The proposed TTS (text-to-speech) system is a hybrid one that combines the advantages of both HMM- and Unit Selection-based TTS systems. The paper deals with the approach based on statistical models of intonation parameters, which makes it possible to preserve the speaker's pronunciation in synthesized speech. We describe the preparation of the database and the solution to the problem of shortage of original speech material for model training. Special algorithms of speech element concatenation and modification are effective to correct parameters according to the requirements, provide overall tonal smoothness and reduce spectral distortion at the boundaries of concatenated elements. Listening tests showed the efficiency of the proposed methods and proved the possibility of highquality speech synthesis even with a small speech database (right up to one hour of speech).

DETECTION OF CLIPPED FRAGMENTS IN ACOUSTIC SIGNALS
Sergey V. Aleinik, Matveev Yuri Nikolaevich, Sholokhov Alexey Vladimirovich

The paper deals with investigation of the method for detecting clipped fragments in acoustic signals with better characteristics as compared with the other known methods. This method is based on the histogram construction for the analyzed signal amplitudes and calculating the distances between the local peaks of the histogram on its tails and in the central part. The difference between histograms of non-clipped and clipped signals is that the histogram of a non-clipped signal has smoothly decaying tails while the histogram of a clipped signal has visible and easily detectable outbursts on its tails. The value of these outbursts and consequently the quality of detection of clipped fragments depends on the parameters of the method under investigation. The main aim of this paper is finding the optimal parameters of the method. Characteristics of the method are studied in detail by mathematical modeling; density functions of target values for different lengths of a studied signal frame and the number of histogram counts and levels of clipping of acoustic signals are built. It is shown that good separation between clipped and non-clipped signal fragments of acoustic signals can be achieved for the frame length between 6000 and 8000 samples and the number of histogram bins between 200 and 300. In this case the threshold level for the best separation can vary between 0.45–0.55. Examples of clipping detector operation based on the proposed method and on real acoustic signals are shown for the case of different clipping levels

TWO-LEVEL HIERARCHICAL COORDINATION QUEUING METHOD FOR TELECOMMUNICATION NETWORK NODES
Maxim V. Semenyaka

98

The paper presents hierarchical coordination queuing method. Within the proposed method a queuing problem has been reduced to optimization problem solving that was presented as two-level hierarchical structure. The required distribution of flows and bandwidth allocation was calculated at the first level independently for each macro-queue; at the second level solutions obtained on lower level for each queue were coordinated in order to prevent probable network link overload. The method of goal coordination has been determined for multilevel structure managing, which makes it possible to define the order for consideration of queue cooperation restrictions and calculation tasks distribution between levels of hierarchy. Decisions coordination was performed by the method of Lagrange multipliers. The study of method convergence has been carried out by analytical modeling.

AN APPROACH FOR CLONE DETECTION IN DOCUMENTATION REUSE
Dmitry V. Lutsiv, Koznov Dmitry V, Hamid Abdul Basit, Ouh Eng Lieh, Mikhail N. Smirnov, Konstantin Yu. Romanovsky

106

The paper focuses on the searching method for repetitions in DocBook/DRL or plain text documents. An algorithm has been designed based on software clone detection. The algorithm supports filtering results: clones are rejected if clone length in the group is less than 5 symbols, intersection of clone groups is eliminated, meaningfulness clones are removed, the groups containing clones consisting only of XML are eliminated. Remaining search is supported: found clones are extracted from the documentation, and clone search is repeated. One step is proved to be enough. Adaptive reuse technique of Paul Bassett – Stan Jarzabek has been implemented. A software tool has been developed on the basis of the algorithm. The tool supports setting parameters for repetitions detection and visualization of the obtained results. The tool is integrated into DocLine document development environment, and provides refactoring of documents using found clones. The Clone Miner clone detection utility is used for clones search. The method has been evaluated for Linux Kernel Documentation (29 documents, 25000 lines). Five semantic kinds of clones have been selected: terms (abbreviations, one word and two word terms), hyperlinks, license agreements, functionality description, and code examples. 451 meaningful clone groups have been found, average clone length is 4.43 tokens, and average number of clones in a group is 3.56.

115

Quality assessment of information security management system is an important step for obtaining baseline data for analysis of the security system control effectiveness, and evaluating implementation of the specified information security requirements of the organization. Proceeding from current analysis practice of information security management systems effectiveness assessment, it can be concluded that, in most cases, independent measurement of security control is carried out without regard to their interaction. The uncertainty of the stochastic nature of the measured security controls is not taken into account. There is a list of related measures for control and management; however, structural elements for measuring of these interactions are absent. Thus, there is an important and urgent task of improving the effectiveness assessing methodology for information security management system that can be solved by introducing a new integral effectiveness indicator of the system, which would give the possibility to take into account the above-mentioned shortcomings.
The author proposes the usage of a new integral efficiency indicator - system response time to information security incidents. This efficiency indicator will make it possible to pass from the binary effectiveness assessment of the system "approve or disapprove" to a quantitative one. New performance indicator gives the possibility to take into account the uncertainty of the stochastic nature of the attributes and measures of management and control, provides a quantitative assessment of the information security state and has a clear physical interpretation for the organization management and information security officers. Dynamics of the indicator change from test to test will assess the information security management system state in general and effectiveness of taken control and management measures. The method for calculating of the new information security management system performance indicator is based on the experimental design theory. Its advantages are: information security service staff has an opportunity to control the attributes measurement, the same accuracy of estimates for attribute parameters during the measurement is provided, interaction degree between attributes and their importance in the computation of the effectiveness of information security management is revealed by means of the regression coefficients, and also an analytical model of performance indicator can be obtained.

MOVING PERSON IDENTIFICATION IN VIDEO SURVEILLANCE SYSTEMS
Alexei Yu. Solomatin, Zikratov Igor Alexeevich, Andrey S. Lyubert

124

The paper deals with an approach for a moving person identifying in video surveillance systems. The proposed solution consists of two successive stages. Selecting of a moving human from all other moving objects in a video stream takes place at the first stage. Human identification based on facial image takes place at the second stage. Detection of a human’s movement is performed via representation of the original video stream in a form of time series. Mathematical apparatus of a singular spectrum is applied for that purpose. The presence of motion is determined by analyzing the periodic components of time series constructed from color and brightness data of the original components of initial video stream. Identification of a person based on his facial image is done through representation of a facial image via two-dimensional matrix with the subsequent application of immune computing mathematical apparatus. Then the binding energy is calculated which shows similarity between the input facial image and faces stored in the training set. The proposed solution for a problem of a moving person’s identifying gives the opportunity to work with low quality video stream having a high level of noise or compression artifacts after encoding. The advantage of the method is implementation simplicity. Unlike traditional methods of computer vision, the proposed method does not require significant computational burden due to simple numerical operations. This method does not require pre-filtering of video images, therefore its performance speed is significantly increased.

### ENGINEERING AND TECHNOLOGIES

MULTISENSOR SYSTEM APPLICATION FOR PREPARATIONS BITTERNESS EVALUATION IN TRADITIONAL CHINESE MEDICINE
Irina S. Yaroshenko, Dmitry O. Kirsanov, Andrey V. Legin, Ping Wang , Ha Da , Hao Wan , Haitong Wan, He Yu

132

This paper deals with the study of preparations based on medicinal plants used in traditional Chinese medicine for treatment and prevention of a wide range of diseases. The purpose of this research was evaluation of the capabilities of a multisensor system for instrumental assessment of the samples bitterness. 33 samples of medicinal plants were evaluated by tasters according to bitterness intensity from 0 to 6. Methodology of the analysis was developed and repeated measurements of the samples were performed by multisensor system. Tasters’ assessments were used as reference data while multisensor system calibrating. A regression model built according to these data displayed good correlation of the system response with bitterness perceived by people. The parameters of the regression model give the possibility for concluding that the multisensor system is capable to predict the bitterness of the medicinal plants preparations with average precision equal to ±1 of the reference bitterness scale. Relative error of bitterness determination is 14%, which is a good result for such type of measurements (typical error of the taster’s assessment is, as a rule, in the range of 15-30 %).

ACCURACY EVALUATION FOR THE NON-CONTACT DEFECT AREA MEASUREMENT AT THE COMPLEX-SHAPE SURFACES UNDER VIDEOENDOSCOPIC CONTROL
Alexei V. Gorevoy, Alexander S. Machikhin, Alexei M. Perfilov

140

The problem of non-contact surface defect area measurement at complex-shape objects under videoendoscopic control is considered. Major factors contributing to the measurement uncertainty are analyzed for the first time. The proposed method of accuracy analysis is based on the evaluation of 3D coordinates of surface points from 2D projections under assumption of projective camera model and Mahalanobis distance minimization in the image plane. Expressions for area measurement error caused by sum-of-triangles approximation are obtained analytically for practically important cases of cylindrical and spherical surfaces. It is shown that the magnitude of this error component for a single triangle does not exceed 1% for the real values of parameters of the endoscopic imaging system. Expressions are derived for area measurement uncertainty evaluation on arbitrary shape surfaces, caused by measurement errors of 3D coordinates of individual points with and without a priori information about surface shape. Verification of the obtained expressions with real experiment data showed that area measurement error for a complex figure, given by a set of points, is mainly caused by ignoring the fact that these points belong to the surface. It is proved that the use of a priori information about investigated surface shape, which is often available from the design documentation, in many cases would radically improve the accuracy of surface defects area measurement. The presented results are valid for stereoscopic, shadow and phase methods of video endoscopic measurements and can be effectively used in development of new non-contact measuring endoscopic systems and modernization of existing ones.

COMPARATIVE ANALYSIS OF ENERGY ACCUMULATION SYSTEMS AND DETERMINATION OF OPTIMAL APPLICATION AREAS FOR MODERN SUPER FLYWHEELS
Maksim A. Sokolov, Tomasov Valentine S, Jastrzębski R. P.

149

The paper presents a review and comparative analysis of late years native and foreign literature on various energy storage devices: state of the art designs, application experience in various technical fields. Comparative characteristics of energy storage devices are formulated: efficiency, quality and stability. Typical characteristics are shown for such devices as electrochemical batteries, super capacitors, pumped hydroelectric storage, power systems based on compressed air and superconducting magnetic energy storage systems. The advantages and prospects of high-speed super flywheels as means of energy accumulation in the form of rotational kinetic energy are shown. High output power of a super flywheels energy storage system gives the possibility to use it as a buffer source of peak power. It is shown that super flywheels have great life cycle (over 20 years) and are environmental. A distinctive feature of these energy storage devices is their good scalability. It is demonstrated that super flywheels are especially effective in hybrid power systems that operate in a charge/discharge mode, and are used particularly in electric vehicles. The most important factors for space applications of the super flywheels are their modularity, high efficiency, no mechanical friction and long operating time without maintenance. Quick response to network disturbances and high power output can be used to maintain the desired power quality and overall network stability along with fulfilling energy accumulation needs.

### MODELING AND SIMULATION

MULTI-GRID METHOD OF CONVERGENCE SPEEDING-UP FOR THE SOLUTION OF GAS DYNAMICS PROBLEMS ON UNSTRUCTURED MESHES
Volkov Konstantin N.

156

An approach for effective implementation of numerical methods and computational algorithms is developed to simulate flows of non-viscous and viscous compressible gas in the complex domains. The convergence speeding-up method of iterative process is discussed based on the usage of multi-grid technologies to the solution of large systems of finite difference equations. Euler and Navier-Stokes equations are quantized on structured and unstructured meshes with highresolution schemes in time and space. Multi-grid method is implemented on the basis of standard C/F splitting of variables and standard interpolation method. A specific approach is proposed to overcome the problems related to storing the matrix coefficients of different signs. A problem of flow around an airfoil is used to demonstrate the possibilities of computational tools developed. The results computed for non-viscous and viscous gas on structured and unstructured meshes are presented with the usage of various components of multi-grid technology. Comparison of computation speed and convergence factors on structured and unstructured meshes showed the economy of the developed approach and weak dependence of quality characteristics on the number of mesh points. The choice of optimal inner iterations number made it possible to decrease computation time for 10%. Obtained results can be applied while software creating for fluid dynamics problems in the complex configuration domains.

EXTENSION OF TENSOR PRODUCT FOR OPERATORS ON THE DIRAC OPERATOR EXAMPLE
Anton A. Boitsev, Neidhardt Hagen , Popov Igor Yu

164

The paper deals with extension method for the operator which is a sum of tensor products. Boundary triplets approach is used. One of the operators is considered to be densely defined and symmetric with equal deficiency indices, the other one is considered to be bounded and self- adjoint. For self-adjoint extensions construction of the mentioned operator, its boundary triplet is constructed in terms of boundary triplet of symmetric operator. Gamma-field and the Weyl function are obtained using the boundary triplet of symmetric operator. Formulas, connecting gamma-field and the Weyl function of symmetric operator with gamma-field and the Weyl function of the studied operator make it possible to use generic resolvent Krein-type formula for all self-adjoint extensions in this case as well. Theoretical results are applied to the Dirac operator, interesting from the physical point of view. Boundary triplet, gamma-field and the Weyl function are constructed for the Dirac operator. The self-adjoint extensions are obtained by Krein formula. Received results can be useful for correct description of quantum systems interaction.

MOLECULAR DYNAMIC SIMULATION OF PEPTIDE POLYELECTROLYTES
Neelov Igor M, Anastasiya A. Mistonova, Anatoliy Yu. Khvatov, Valeriy V. Bezrodny

169

The paper deals with investigation of the conformational properties of some charged homopolypeptides in dilute aqueous solutions by computer simulation. A method of molecular dynamics for the full-atomic models of polyaspartic acid and polylysine with explicit account of water and counter-ions is used for this purpose. For systems containing these polypeptides we calculated time trajectories and the size, shape, distribution functions and time correlation functions of inertia radius and the distances between the ends of peptide chains. We have also calculated the solvatation characteristics of considered polyelectrolytes. We have found out that polyaspartic acid in dilute aqueous solution has more compact structure and more spherical shape than polylysine. We have shown that these differences are due to different interaction between the polypeptides and water molecules (in particular, the quality and quantity of hydrogen bonds formed by these peptides with water), and the difference in an amount of ion pairs formed by the charged groups of the peptides and counter-ions. The obtained results should be taken into account for elaboration of new products based on the investigated peptides and their usage in various industrial and biomedical applications.

### BRIEF PAPERS

IDENTIFICATION OF NONLINEAR MODEL PARAMETERS FOR RAPID THERMAL PROCESSES
Kapitonov Alexander A, Aranovskiy Stanislav V.

176

A problem of parameters identification is considered for a nonlinear model of rapid thermal processes. A hybrid
approach is proposed for parameter estimation combining both analytical solution and numerical optimization. At the first step, the rate of temperature change is estimated from experimental data, which makes it possible to rewrite the considered nonlinear model as a linear regression and estimate the parameters by the least-squares method. Further, this estimation is used as an initial guess for numerical optimization of prediction error minimization problem, thus the optimal predictor is obtained. The proposed approach was verified at an experimental setup for vapor deposition processing; the resulting estimates provide high-quality temperature prediction.