Subject of Research. The paper presents the study of optically tunable terahertz filter based on cross resonators coated with a layer of carbon nanotubes (CNT). We show experimentally control capability of the optical spectral characteristics of terahertz devices coated with a layer of single-wall carbon nanotubes. Method. The empirical formulas were used for calculation of the geometrical parameters of a cross-shaped resonator for a given resonant frequency and filter Q-factor. Experimental samples of the notch filter were made by laser engraving. A layer of carbon nanotubes, which were synthesized by aerosol chemical deposition, was deposited on an experimental filter sample. Experimental transmission spectra of an “empty” filter, a filter with a carbon nanotubes layer without pumping, and an optically pumped carbon nanotubes layer filter at a wavelength of 980 nm were measured by terahertz time-domain spectroscopy. Main Results. We have shown by experiments that optical pumping of a filter with carbon nanotubes layer leads to a decrease in the transmittance of the main resonance peak and a shift towards higher frequencies of the side resonance peak. Practical Relevance. Filters coated with carbon nanotubes layer can be used as inexpensive and compact tunable components for terahertz photonics devices

Subject of Research. The paper presents a novel method for creation of an artificial space object “depth map”. The analysis of methods for creation of three-dimensional image of an artificial space object by laser locator is performed and the experimental study results are presented. The following television location methods form the basis for development. The first method of television location proposed by P. S. Vargin was developed in “Television Scientific Research Institute” (St. Petersburg, Russia). The method provides for creation of a “depth map” for remote artificial space object in a double flight time of one light pulse from the observation point to the object. The second method is used in the pulse range determination system and is based on flash-lidar performance. This system irradiates the space area of interest where the object of observation is supposed to be located; the reflected signal from the object is first recorded by a photodiode and the distance to the object is estimated. Then the object three-dimensional image is built on a certain number of points. The third method is a multi-pulse system of television laser locator based on the use of multi-pulse illumination for the study of the object under observation. Thus, it is possible to increase significantly the resolution in depth up to 10–50 mm and reduce the peak power of the laser radiation. Method. A novel method of multi-pulse illumination of an artificial space object is proposed on the basis of the considered methods in order to increase the energy of the optical signal. The method is based on the use of the charge-coupled device matrix in the mode of ultra-short accumulation time (up to 200 ns). This method enables rapid high-precision measurement of angular resolution (0.25 ang. min), range to the target (100–2000 m) and a “depth map” creation. Main Results. A laser system model was developed consisting of a television camera based on the charge-coupled device with a resolution of 752×582 pixels, a frame frequency of 50 Hz, and a laser diode with minimum pulse duration of 40 ns and a pulse repetition rate of 1 kHz. Control and synchronization of the laser is carried out by FPGA installed in the television camera ensuring the synchronization of the camera and the emitting laser. The system gives the possibility to realize interchangeable relations of distance measurement accuracy, angular and time resolution. The simulation has showed that the measurement error at small distances is less than 20 mm, and at a distance of 2000 m is less than 160 mm. Practical Relevance. The obtained results determine the characteristics of the television laser system necessary to solve the location problem for artificial space objects at a range from 100 m to 2000 m. Analysis of studies shows that modern lasers are aimed at operating in the spectral range of 1.54–1.57 μm, that reduces significantly the efficiency of the television laser system from 2 to 10 times. Therefore, it is necessary to implement laser systems with wavelengths of 0.86–1.06 microns to improve the tactical and technical properties for space inspection.

This work aims on method development for obtaining initial designs for ultraviolet (UV) and deep-ultraviolet (DUV) objectives through global search algorithm. We studied a global search based algorithm tending to obtain the feasible local minima of lens design landscape. One of the major challenges of our work is writing macro input related to a number of lenses, the length of objective, and glass material. The obtained results show the main advantages and efficiency of the design approach based on the global search algorithm. As an output, we developed a method and criteria for successful selection of the starting point of micro-lithographic objectives

Subject of Research. The paper considers hydro-lenses for the study of the World Ocean, including its Arctic zone. The issues of work at shallow depths and the shelf are regarded as having been resolved; the work is actively carried out at medium depths, 300–500 meters, therefore, the projects involving the study of deep water become the most relevant. These tasks are complex and multidisciplinary and, surely, require large scientific, technical and financial investments for their solutions and are able to ensure the replacement of expensive imported equipment. In terms of complexity, they are not inferior to the issues of space exploration. Method. Maximum attention is paid to the design of specialized optical systems that provide the formation, input and transmission of visual information from distant objects, which cannot be obtained by any other means. It is important to understand the role and purpose of each element in the design of such systems. This knowledge helps the developer to find the optimal solution for selecting the starting point of the optical system. The design methods were based on the experience of ITMO University in the development of optical schemes for hydro-lenses and their implementation in national projects for the World Ocean exploration. The main approach used in the design of hydro-lenses involves combining the analysis of the known solutions, their classification, recommendations of opticians-experts skilled in the art, as well as structural and parametric synthesis with subsequent automated correction of lens circuits. In recent years, virtual prototyping of models of hydro-lenses and their interaction with the external environment has been actively used. Main Results. The main results and their practical significance consist in calculation procedure development for hydro-lenses intended for deep-sea exploration and the creation of a number of hydro-lenses for solving applied scientific problems. The paper presents diagrams of certain lenses. Practical Relevance. The developed hydro-lenses can be used to solve various scientific and economic problems at deep waters of the World Ocean, up to the maximum ones.

Subject of Research. This paper presents the results of an experimental study on the possibility of applying single fiber Bragg gratings as sensitive elements for detecting ultrasonic impacts in gaseous or liquid media and at placing fiber Bragg gratings into various materials and structures for their status monitoring. Method. During the experiment, an ultrasonic impact with a fundamental frequency of 65 kHz was alternately turned on two sensitive elements based on two fiber Bragg gratings with different parameters: the physical grating length, reflection coefficient, and slope of the linear part of spectral characteristics. Comparative analysis of the obtained data with data from the reference piezoelectric ultrasonic sensor was performed. The results were evaluated in the frequency domain, at the range up to 200 kHz. The three first harmonics of the signal were studied: 65, 130 and 195 kHz. The signal-to-noise ratio for each sensor element and the ratio of signal values obtained from various sensor elements were evaluated. Main Results. The measurement setup was created on the basis of a small-sized tunable VCSEL and FPGA. It is shown that single fiber Bragg gratings are suitable for creation of sensitive elements for ultrasonic sensors and have values of sensitivity and dynamic range comparable to piezoelectric sensors. The range of detected frequencies was theoretically estimated and the assessment of the FBG parameters effect on the sensor sensitivity to ultrasonic action was performed. The ratios of the signals measured by the Bragg grating with a slope of the spectral characteristics equal to 142 1/nm and a reflection coefficient equal to 100%, to the signals from the grating with a slope of 44 1/nm and a reflection of 40% are equal to 5.8, 3.8,7.1 for 65, 130 and 195 kHz, respectively. The ratios of the signals measured by the reference piezoelectric sensor to the signals measured by Bragg grating with a slope of the spectral characteristics equal to 142 1/nm and a reflection coefficient of 100% are 3.8, 6.2, 7.7 for 65, 130 and 195 kHz, respectively. Practical Relevance. The results of this study show the possibility of applying fiber Bragg gratings as the sensitive elements of threshold and measuring ultrasonic sensors for the placement in the volume and on the surface of the materials under study. The features and advantages of fiber-optic measuring systems provide the ease of installation for the arrays of sensors in the material or structure under research during production, insensitivity to external electromagnetic interference and the possibility of multiplexing a large number of sensitive elements on a single optical fiber.  

Subject of Research. The paper proposes a method for determining the rotation parameters of the basic unit of an optical- electronic deflectometer, having an effect on the deflection measurement error of large-scale objects such as a floating dock. Method. We proposed an algorithm and mathematical model structure for the effect of the image coordinate estimation error of the collimating mark on the rotation parameter estimation error of the deflectometer basic unit with the use of the elements of vector algebra and matrix analysis. Main Results. We have proved that the rotation parameters of the basic unit can be determined as a result of solution of nonlinear equation systems based on the Levenberg–Marquardt optimization algorithm. Studies on a mathematical model have given the possibility to estimate the effect of the image coordinate estimation error of the collimating mark on the rotation parameter estimation error of the basic unit. Practical Relevance. The results of this work will enable us to develop an algorithm for compensation of the basic unit rotation parameters due to the effect of external factors and, as a result, to reduce the error in determining the spatial coordinates of the controlled object (deflection of the floating dock).

Subject of the Research. The paper presents the study on the effect of object representation form on the depth resolution of images reconstructed via computer-generated Fresnel holograms-projectors. Method. The study was performed by mathematical modeling of synthesis and reconstruction of holograms-projectors of various objects with a characteristic size of 20 × 20 in virtual space. The method is based on object wave representation at hologram synthesis as a superposition of object waves emanating from two identical objects located at different distances from the hologram synthesis plane. All numerical experiments were carried out using a specialized software package with the following parameters for the synthesis and reconstruction of holograms: the wavelength of the radiation used is 13.5 nm, the pixel size of the hologram is 20 × 20, the distance between the object and the hologram planes is 20.3 μm, the reference wave angle of incidence is 14.7 °. The quality criterion of the reconstructed image was expressed in terms of the number of gradations at the threshold processing of this image with the intensity distribution in the reconstructed image identical to the intensity distribution in the original object. Main Results. Following the carried out experiments, the dependence was drawn out for the depth resolution of the images reconstructed by computer-generated Fresnel holograms-projectors on object representation form. In particular, it was found that full object representation based on transparencies is the most effective rather than representation of just one its part with the small-sized elements of the object structure. Practical Relevance. The application of this method makes it possible to optimize the object structure parameters, that is, the form and sizes of its elements during the synthesis of Fresnel holograms-projectors with the higher depth resolution for holographic photolithography.

Subject of Research. The paper presents geometrical synthesis results of kinematic schemes for a femur and a whole leg mechanisms of a cheetah robot, which is able to jump in place and run at various speed. We substantiate the topology of mechanisms, describe their operation principles, characteristics and distinctive features, involving the controlled reconfiguration of mechanisms for changing the trajectory of the ground-contact point, and the use of flexible elements and links with variable length to ensure energy-efficient locomotion. Method. A structure scheme of the whole cheetah robot leg was obtained by attaching four movable links to the femur mechanism, imitating large and small tibial bones, metatarsus and sartorius muscle. The obtained structure was decomposed into three mechanism components: a “minitaur”, two-rocker four-bar lambda mechanism and a rocker-slider mechanism. The kinematic schemes of the above-mentioned mechanisms were synthesized by the method of extreme discrete positions with the result that the kinematic scheme of the whole leg with intermediate positions was obtained. The parametric optimization algorithm was described and the minitaur objective function was given using mathematical programming. Main Results. The kinematic scheme of the whole cheetah robot leg is obtained in the first approximation without taking into account the robot dynamics, location of flexible elements and their resonance necessary for the resonance behavior in order to achieve energy-efficient movement. Modeling results of the robot dynamics according to the synthesized scheme are given. Stable behavior is obtained both while jumping in place and running. Practical Relevance. The study is carried out for the development of an energy-efficient four-legged galloping cheetah robot performing energy recovery with the help of flexible elements. The synthesized kinematic scheme is applicable for detailed analyzes of dynamics, kinetostatics, energy recovery and losses upon impact with the ground surface, and for the robot prototype design.

Subject of Research. We study the effect of physical and chemical properties of finely-dispersed coal sludges of “MMK-UGOL” on their floatability. Method. Petrographic analysis of coal was carried out using the analyzer of petrographic properties of SIAMS 620 coal. To identify the presence of the main functional groups in the macromolecule of the organic mass of coal, the method of automated analysis of coal by infrared reflection spectra (IR-spectrum) was used. The electrical conductivity of the pulp with a crushed coal sample was determined by ANION 4100 liquid analyzer. Flotation studies were carried out in laboratory flotation machine of FML-1 type (Research and Production Company “Mechanobr-Technika”, Russia). Main Results. The action mechanism of new reagents in the flotation of finely-dispersed coal sludges has been identified. The flocculating action of “Sinterol” new reagent on the mineral particles of finely-dispersed coal sludges has been elucidated, that improves significantly the selectivity of the flotation process. The optimum flotation mode of thin coal sludges has been developed on the basis of laboratory researches, which increases resource efficiency of coal enrichment technological process due to the decrease in organic weight loss with waste by 33%. Thus, the consumption of the consumed reagents is reduced by 3 times. Practical Relevance. The efficiency of “Sinterol” reagent-flocculant has been confirmed by industrial tests on JSC MMK-COAL (Russia). Thus when applying “Sinterol” reagent- flocculant in the flotation process in an amount of 0.001–0.003 kg/t and simultaneously reducing the total consumption of reagents by an average of 13.0% from 3.000 to 2.613 kg/t, the concentrate yield has increased by 2.5–8.5%, the ash content of the concentrate has decreased by 2.7–3.0%, while the ash content of waste has increased by 2.9–12.3%.

Subject of Research. The paper presents the results of experimental study on the specific features of argon ion beam effect on a sapphire surface at small grazing angles. Mechanically ground and defective epipolished leucosapphire plates with 20 × 20 × 1.2 mm in size were used as experimental samples. The initial surface roughness of the polished samples was 0.250–1 μm and of the epipolished ones was 5–10 nm. Method. The ion beam deposition setup was used for research. It includes the ion source of CLAN-53M type with ion neutralizer. The ion source generates ion flux with energies in the range of 150–1500 eV, with an output ion current density up to 4 mA/cm2, with ion current from 10 to 80 mA. The studies were carried out at different technological parameters of ion-beam polishing: the ion energy and the angle between the sapphire surface and the ion beam axis α. Main Results. We have determined effects of sapphire surface morphology change both with preservation and change in the overall roughness level, and the effect of surface structuring during processing in two projections with the formation of flat peaks with a diameter of 2 μm. The experiment results have shown that the maximum efficiency (the highest value is a change in the arithmetic average surface roughness) during ion-beam polishing is observed at α equal to 15° and the ion beam energy of 400 eV. When α value changes from 25 to 30°, an oriented change of the surface morphology from the symmetrically ordered surface microrelief to an asymmetric one occurs. At the same time, the flat sides do not bleed much, and the effect of steep shadow smoothing of the local microrelief is observed with retention of the same general roughness level. After the sample surface processing with ion beam at the first stage of the experiment, it was re-processed at 90° angle relative to the previous treatment, which led to cross-spraying of the shadow sections and the design of gentle peaks with a diameter of about 2 μm (effect of the substrate surface structuring). Practical Relevance. After the ion-beam polishing of epipolished sapphire substrate samples, smoothing of the highest surface irregularities is observed, and the average arithmetic value of surface roughness has decreased from 5.7 nm to 0.9 nm for the polished sample.

Subject of Research. We consider а new mathematical modeling method for synthesis processes of carbon nanostructures in plasma. The method is characterized by the use of the Boltzmann kinetic equation and particle distribution functions taking into account the paired elastic and inelastic collisions. The widespread use of nanotubes, fullerenes in modern industry is limited by the high cost and low productivity of synthesis methods due to insufficient theoretical study of their formation processes. The aim of the work is to build a model of the processes for obtaining various carbon nanostructures in arc discharge plasma andthe development of effective numerical methods for calculating the conditions improving the synthesis efficiency. Method. The paper presents a method of numerical solution of the considered multidimensional nonlinear problem with the use of nVidia CUDA technology in combination with the parallelization technology on the central and graphic processors. The method gives the possibility to obtain cost-effective solution by applying limited computing resources on a personal computer. Main Results. The developed model makes it possible to describe adequately the processes of formation and growth of cluster groups, which are the basis for the formation of carbon nanostructures in arc discharge plasma, and also to take into account the effect of synthesis conditions on the final product output. Practical Relevance. The developed mathematical model and its elements can be used in the design of plants for the synthesis of carbon nanostructures by thermal evaporation of graphite.

Subject of Research. We consider а new mathematical modeling method for synthesis processes of carbon nanostructures in plasma. The method is characterized by the use of the Boltzmann kinetic equation and particle distribution functions taking into account the paired elastic and inelastic collisions. The widespread use of nanotubes, fullerenes in modern industry is limited by the high cost and low productivity of synthesis methods due to insufficient theoretical study of their formation processes. The aim of the work is to build a model of the processes for obtaining various carbon nanostructures in arc discharge plasma and the development of effective numerical methods for calculating the conditions improving the synthesis efficiency. Method. The paper presents a method of numerical solution of the considered multidimensional nonlinear problem with the use of nVidia CUDA technology in combination with the parallelization technology on the central and graphic processors. The method gives the possibility to obtain cost-effective solution by applying limited computing resources on a personal computer. Main Results. The developed model makes it possible to describe adequately the processes of formation and growth of cluster groups, which are the basis for the formation of carbon nanostructures in arc discharge plasma, and also to take into account the effect of synthesis conditions on the final product output. Practical Relevance. The developed mathematical model and its elements can be used in the design of plants for the synthesis of carbon nanostructures by thermal evaporation of graphite

Subject of Research. The paper considers various methods for coating synthesis on molybdenum and heatproof materials. We propose the method of molybdenum blackening technology improvement. Method. The first method involves holding the sample in deionized water for some time after pretreatment, and the second one is characterized by its absence. During the experiment, the samples were taken three-stage treatment comprising etching in an aqueous solution containing HF and HCl for ten minutes. After that, the samples were immersed in a container with an ammonium molybdate solution, where the deposition of coating was carried out by electrochemical method. Main Results. The studied black coating is high resistent, in particular, it can be washed out only using the strong acid (for instance, the nitric acid) and can not be eliminated with alkali solution as well as wire brushing. But the first sample coating is short-lived and it comes off the sample surface in course of time. During the second experiment with the modified technology the applied coating becomes cracked eventually, but it does not break away from the surface. The coated samples were stored at normal temperature and pressure. The study of coated samples deterioration was carried out by Inspect SEM FEI scanning electronic microscope. Practical Relevance. The study results can be used for design of optical equipment new samples, in particular, for applying light-absorbing coating on molybdenum parts. The following black molybdenum coating technology improvement can be based on this work as well.

Subject of Research. We introduce a novel method for resolving temporal incoherence in two-dimensional color Doppler echocardiography (2D CDE). Incoherence occurs when the temporal distance between frames is less than frame duration. This happens for frame reordering algorithms, which is a widespread processing method. Existing solution — temporal weighting — requires a lot of time for processing (more than 2 seconds per frame) and is not designed for blood flow data. Method. In the proposed method, the weights are calculated not per pixel, but per image subsector obtained by a specific precomputed mask,utilizing the mechanics of the acquisition process. Pixels with opposite blood flow directions are weighted separately with the further weights comparison. We evaluated the algorithm with 10 animal epicardial 2D CDE datasets of the right ventricle. Main Results. Measurements of differences in execution time and results (pixel intensities) with temporal weighting have shown the order of magnitude increase of processing speed from 0.40 frame/s to 4.63 frame/s. Pixel intensity changes inconsiderably: the average difference value is , maximum with intensity values lying within integer range of. Practical Relevance. The proposed algorithm can be embedded into reordering-based 2D CDE processing pipelines in order to obtain temporally correct results. In addition, the processing speed is close to real-time.

Subject of Research. The paper considers approaches of vibration resistance increasing for quartz pendulum accelerometer with digital feedback amplifier and without further development of measuring element design or application of damping measures. Method. The proposed methods are implemented algorithmically by means of the control program of the digital amplifier controller and are based on the extension of the device bandwidth, the correction of the regulating coefficients during the accelerometer operation, and the introduction of an additional control channel to the feedback loop. Main Results. The proposed methods were studied experimentally on a prototype quartz pendulum accelerometer with a digital feedback amplifier and a measuring range of ±50 g. The studies were carried out under the effects of vibration actions: broadband random vibration in the frequency range from 20 to 2000 Hz, (RMS deviation of the vibration acceleration amplitude of 8 g) and sinusoidal vibration in the frequency range from 20 to 2000 Hz (vibration acceleration amplitude of 10 g) along the sensitivity axis. The efficiency of the methods was estimated by the value of device vibration error — the difference between the averaged value of the device readings before vibration and the averaged value of the readings during the period of vibration. It was experimentally established that the best solution is to combine a wide bandwidth of the device with an additional control channel in the feedback loop, that reduces the accelerometer vibration error by an order of magnitude. Practical Relevance. The proposed methods increase the vibration resistance of a quartz pendulum accelerometer by applying original algorithms in the digital amplifier controller program, that makes it possible to put to use such accelerometers in objects susceptible to vibration while eliminating the need to introduce physical design modifications or additional damping measures.  

The paper presents the developed approach of creating a decentralization personal data information system, based on the blockchain technology. The approach includes proposals for overall system architecture specification, data storage procedure, users’ fee, consensus mechanism, and system implementation and enhancement. Data storage is provided with the use of personal users’ devices and information cryptographic protection facilities. The users’ fee mechanism is based on the social credit system, employed in China, which ensures the selection of the most trustworthy personal data subjects able to play the role of consensus nodes. Consensus procedure includes automated risk analysis of unreliable data processing. A neural network theory and fuzzy set theory are proposed as the mathematical tools of risk analysis. The use of an artificial neural network provides flexibility of the system as a whole in terms of the growing number of users. The proposed approach application for decentralization information system design will provide for improvement of availability, integrity and confidentiality of data through decentralized processing and application of well-studied cryptographic protection methods

Subject of Research. The paper considers a concept of platform approach for automated electronic devices design. The concepts of “platform-based development” and “unification and standardization of developments” are compared. Analysis was carried out on our own examples of ellipsometric equipment family development and the development of a nanosatellite platform of the CubeSat standard. Method. The decomposition of these platform solutions into unified modules is presented. Quantitative indicators of project-to-project unification were calculated for these two cases in accordance with regulatory documents. By experience, the typical value of the project-to-project unification indicator specified in the technical tasks for the development of devices ranges from 60 % and higher. Main Results. For the family of ellipsometers the value of project-to-project unification coefficient equal to 96.3 % was calculated. For the nanosatellite platform a value of project-to-project unification coefficient equal to 84 % was obtained. Both values exceed significantly the value of typical given values. It is shown that chosen fragmentations of platforms into unified modules outlined in the paper are optimal from functional differentiation between modules point of view. Practical Relevance. Advantages of the platform approach are demonstrated on personal experience of development of high- speed ellipsometric equipment and a universal nanosatellite platform of the Cube Sat standard. It is shown that the obtained high rates of unification are achieved due to the modular principle implementation for design of electronic subsystems. Years of successful experience in effective design of new automated devices within the existing platform is consistent with qualitative calculations. The quantitative value of standardization and unification indicators can serve as a main factor for the adoption of engineering and management decisions on changes in the products being developed.

Subject of Research. The paper demonstrates the similarity of the traffic organization in the information and communication network that performs data delivery to its users and the transport network that performs the transport function. It is shown that almost complete similarity for elements of the information and communication network and the transport network is in structural and functional terms; there are similarities in the formulation of tasks being solved on networks during macro modeling, and the models are equivalent for many objects. Methods. Model support of information and communication networks as a complex stochastic object of research can be adapted for the transport network when solving assessment problems of the traffic flows distribution to the networks and transport routing, identification of emergencies and bottlenecks in the network with the aim of their well-timed deletion. Main Results. A three-level conceptual model is proposed, which demonstrates the similarity of the transportation organization in the infocommunication network and the transport network. The correspondences of the elements of the infocommunication network and the transport network according to their functional purpose are given. Analytical and statistical modeling is proposed for applying in conjunction with accelerated modeling in the design of transport networks. Practical Relevance. The occurrence of inter-sectoral models provides for solving optimization problems for the methods and structure of production management in various application areas.

Subject of Research. The paper considers the problem of choice and comparison of multicarrier schemes in cellular networks. The schemes are compared with Orthogonal Frequency Division Multiplexing which is a current choice for the 5th generation networks. Reviewed schemes are evaluated by their effect for the Internet of Things scenario. We consider the effect of applyingwireless sensor networks as sensors along highways. Also alternative multicarrier schemes are evaluated based on possible improvements in conventional cellular networks. Method. The schemes proposed for implementation were compared by criteria significant for the IoT. The possible improvement of base station reach was evaluated with respect to parameters defined in 5G and New Radio specifications, developed by The Third Generation Partnership Project Consortium. Main Results. Analytical method for improvement evaluation of base station reach while implementing of alternative multicarrier schemes is formulated. Base station reach increase is the result of higher power efficiency occurring at reduction of radiated power out of specified bandwidth (“side lobes”) and the peak to average power ratio. The performed modeling has shown that base station reach increase in case of “Universal Filtered MultiCarrier” scheme implementation in 5G networks is approximately 12%. Practical Relevance. Obtained results can be of practical use in decision-making regarding the implementation relevance of alternative multicarrier schemes in cellular networks after 5G. According to the higher reach it is possible to evaluate the increase in number of subscribers when their area density is fixed and, consequently, the lowering in capital expenditures on network deployment if the number of base stations is decreased.

The paper presents a portal developed for remote rehabilitation of patients with various neurological pathologies. The distinctive features of the developed system as compared with the existing ones are: the possibility of patient communication with the attending doctor, timely updating of the patient’s individual trajectory of rehabilitation, control of the rehabilitation results through online monitoring of the patient’s health condition by the video recording function integrated into the system, rehabilitation opportunities for patients in outlying areas of the Krasnoyarsk Territory. The software implementation of rehabilitation is based on proprietary medical methodologies developed at the Department of Nervous Diseases with a course of medical rehabilitation for postgraduate education at Krasnoyarsk State Medical University named after V.F. Voyno-Yasenetsky (Scientific Supervisor is MD, Professor S.V. Prokopenko). The paper pays special attention to the functionality of the remote rehabilitation system for the users with the roles: “Doctor”, “Patient” and “Administrator”. Screenshots of the portal are presented. The system is a classic Web application built on free software. The presented work can be useful to neurorehabilitation specialists of the Krasnoyarsk Territory and to specialists throughout Russia. The proposed information system can be also used for patients’ rehabilitation exercise training of doctors and nurses.remote rehabilitation, neurorehabilitation, information system, information system functions, database, home rehabilitation, information and communication technologies

Subject of Research. The paper presents results of the management system development for a scalable geographically distributed data center. Special attention is paid to system versatility in view of new tasks, resource efficiency, operational reliability in the conditions of system component failures, and information access security. Method. An approach based on technologies of software-configured infrastructures was used. The technical solutions of the created software components were implemented on the basis of free and open source software. Quantum communication technologies at the side frequencies were used for protection of the data links between the local data processing centers as part of a scalable geographically distributed data center. The components of the developed integrated management system were implemented in the form of software agents running in an operating-isolated environment. Main Results. The hardware-software complex has been created, functioning according to the “Infrastructure as a Service” model. Experimental studies of the integrated management system were carried out on a prototype of a scalable geographically distributed data center built together with the SMARTS Ltd company (the city of Samara). These studies have shown the feasibility and high efficiency of the designed solutions meeting the technical requirements for the development. Practical Relevance. The considered hardware-software complex can be used in the formation or modification of a scalable geographically distributed data center primarily by government organizations, since it is an indigenous Russian technology without applying borrowed proprietary software. The system components can be used in the development of private cloud infrastructure.

Subject of Research. The paper presents a software building method for the tasks of deformable solid mechanics. This software should guarantee high accuracy and speed of calculations, as well as simple preparation of the initial data and data processing even for an inexperienced user. The software was developed using the open source GMSH mesh generator application programming interface (API) and the Eigen mathematical library. Method. The developed software consists of three modules: GMSH_API, InputFile, FEMSolver and a database. The GMSH_API module, which prepares the finite element model, was written using the GMSH mesh generator API. The InputFile module describes methods for interacting with a previously created database, that provides quick and easy preparation of the input file needed to start the calculation. Numerical calculation by the finite element method is implemented in the FEMSolver module. The Eigen mathematical library was actively used for its implementation, and it can build sparse matrices that do not store zero elements in memory. This possibility obviates the need for additional transformations of the global stiffness matrix used in the finite element method. Main Results. The Kirsch task was solved as an example in a plane-stressed setting: a distributed tensile load was applied to the upper edge of a steel plate, with a round hole in the center, the lower edge of the plate was rigidly fixed. After calculating and obtaining the von Mises stress distribution field in the plate, we observe an error of 1.72% relative to the analytical solution. Such error value is considered low, therefore, the developed software not only facilitates the preparation of data for calculation, but also guarantees high accuracy of the obtained results. Practical Relevance. Commercial software for solving the problems of deformable solid mechanics, such as ANSYS Mechanical APDL, Abaqus, etc., is very expensive. Free software is primarily focused on researchers and, as a rule, is difficult for learning by an ordinary user-engineer, and the compromise version of the PDE Toolbox for MATHLAB is applicable only for tasks in a two-dimensional area and only supports a linear triangular finite element. However, the application of GMSH API and the Eigen library provides for creation of an easy-to-use but powerful tool for solving the problems of deformable solid mechanics.

The paper presents the study of surface layer structure of two nacre samples, plates of which served as mosaic elements in a subject of decorative art, by spectral optical coherent microscopy method at the wavelength range 1305 ± 75 nm with 10 μm scanning depth resolution. The mesolayers structure with thicknesses of 230 and 360 μm was observed within the B-scan of nacre layer for Haliotis shell. The tomogram of the second nacre sample is characterized by greater nonuniformity of layers’ distribution through the scanning depth, strong scattering of probe radiation, and the microstructure of nacre is visualized in depth up to 1.6 mm. Comparison of the nacre sample layers structure by the optical coherence microscopy method provided for distinguishing their different biological origin. Analysis of the area for mosaic elements clamping to a base of the product is performed and the glue layer thickness is determined in the range from 67 microns to 120 microns.

We present a new framework of generative adversarial network for training of acoustic model for speech synthesis. The proposed generative adversarial network consists of a generator and a pair of agent discriminators, where the generator predicts the acoustic features from the linguistic representation. Training and testing were carried out on the Kazakh speech corpus, which consisted of 5.6 hours of speech recording. According to the experiment results the 3.46 mean opinion score was obtained which shows an acceptable quality of speech synthesis. This approach of the acoustic model development can be applied in speech synthesis systems of the other languages.

Subject of Research. The paper considers an algorithm for the formation of color QR-codes for facial biometrics. Methods. The methods are based on image processing procedures, linear algebra methods and are implemented in MATLAB package environment. Main Results. We present a new graphics object: a color biometric QR code and a method of forming color QR codes in biometrics tasks. An algorithm for its implementation is described, a functional diagram of the device for its implementation is shown, examples of various variants of color biometric QR codes are given. Practical Relevance. The results obtained can be used in practical biometrics and its applications, and for creation of new types of test databases for face images