Subject of Research. The paper presents results of the experimental and theoretical studies on cesium distribution effect along the vapor cell walls of quantum rotation sensor on the quality of parametric resonance in cesium. Methods. Theoretical and experimental studies were performed using the mathematical model, quantum rotation sensor layout and the laboratory setup for the vapor cell parameters research. The mathematical model was used for calculation of cesium relaxation rate theoretical value at various temperatures and further comparison of these data with experimental ones. For the experimental determination of cesium relaxation rate, the data on the parametric resonance width in cesium obtained on the of the quantum rotation sensor model were used. Studies of the cell optical properties were carried out on a laboratory setup in non-resonant light. A laser with a vertical emitter similar to the one used in the quantum rotation sensor is applied as a source of non-resonant light, tuned away from the nominal wavelength. The optimal detuning of the optical radiation frequency from the cesium resonance was determined on the laboratory setup, that reduces the dependence of the measurement results on the cell temperature. Selection of laser radiation optimal parameters is performed for the normal mode of the laser operation and freedom from fluctuations in its power and polarization. Main Results. During the research it was shown that undesirable cesium redistribution in the vapor cell leads to the optical paths transparency change, which causes the deterioration of the signal-to-noise ratio and the decrease in the resonance line quality factor. In addition, it was shown that cesium resonance line broadening due to sedimentation of the cesium vapor on the cell walls is insignificant and is at the level of the measurement error. Practical Relevance. We have proposed and tested non-resonant light intensity control method for the laser emitter after passing through a vapor cell. This method provides for an operative state monitoring of the optical pumping channels and detecting of quantum rotation sensor layout.

Subject of Research. The paper deals with the problem of seismic streamers towing process during marine geological exploration. Classification of the mechanical noise effects during towing process is presented. A brief overview of the main technical solutions is performed for suppression of each impact type. Method. A method is proposed for calculating the parameters of elastic sections for suppression of noise effects, which takes into account towed body tension level. We show the possibility and prospects of applying for this purpose a fiber-optic strain measurement system based on Bragg gratings inscribed in the G.657.A1 standard SMF-28 telecommunication optical fiber with a sampling rate of 5 kHz as part of a fiber-optic seismic streamer design. Main Results. Experimental data on the prototype research are given. With the relative elongation of the uniform-strength bar in the range up to 1030 μm/m, an average sensitivity of 0.68 pm (μm/m) is achieved, and the spread of values is ±1 pm. It is shown that the work of fiber Bragg gratings is practically non-inertial itself. The response time and dynamic range of the sensor amplitude is largely determined by the properties of metal bars and tool set where optical fibers are fixed. Practical Relevance. Application of the method provides opportunities for the solid construction of the towed body. The possibilities for calculation of the elastic section parameters to the specific conditions of marine geological exploration and continuous state monitoring of the towed body are presented. The method makes it possible to control the quality of the recorded seismic data and partially compensate the undesirable effects during signal processing. Proposed measures will increase significantly the accuracy and reliability of the obtained geological data.

Subject of Research. The paper presents comparison of two different spectroscopic methods for the quantitative determination of the secondary structure components of two globular proteins with different secondary structure, such as human serum albumin and porcine trypsin. The variability and reproducibility of each method are analyzed. Method. The secondary structure of proteins was determined by two common spectroscopic methods for quantitative assessment of protein secondary structure, such as deconvolution of amide I absorption band in the infrared spectrum and deconvolution of infrared spectrum second derivative in the frequency range of amide I. We used spectra after subtraction of the solvent spectrum from the protein solution spectrum for these methods. Main Results. Comparison of two spectroscopic methods shows that the second derivative deconvolution method for protein infrared spectrum provides greater reproducibility of the secondary structure components in independent experiments compared to the decomposition of the spectrum in the amide I absorption band for both albumin and trypsin. The coefficient of variation in the second derivative deconvolution also has a small value, therefore, the method of the second derivative gives a more accurate determination of the protein secondary structure as opposed to the contour decomposition of amide I band. The obtained results of the second derivative deconvolution are in better agreement with computational methods and X-ray analysis. Practical Relevance. Experimental results obtained by comparison of different methods of secondary structure quantitative determination for proteins allow choosing the most accurate calculation method, which can provide information on the structural stability and dynamics of protein in various media and assess the content of protein secondary structures.

Subject of Research. The paper considers the problems of synthesis and analysis automation for the cemented doublet with the possibilities of achromatization and synchronous passive athermalization. We present an algorithm for such automation and give an example of the cemented doublet development using this algorithm. Methods. Component synthesis with regard to achromatization consists in selection of a pair of glasses and calculation of the curvature radii for a system of two infinitely thin cemented lenses with given values of three parameters determining the spherical aberration of the third order (P), the thirdorder coma (W) and chromatic aberration (C) according to Slusarev procedure. Passive athermalization is performed using the method of nomograms. In contrast to the traditional visual selection of a pair of glasses, a value is calculated for evaluation of the system thermo-optical properties and the result is displayed in the summary table. Main Results. The developed algorithm gives the possibility to extend the modular design principle most commonly used for aberrational calculationsto the calculation of thermal defocusing. An example of algorithm application is given demonstrating defocusing value less then diffraction focus depth. Practical Relevance. The developed method simplifies and speeds up the stage of materials selection for the designer or engineer during the preprocessing calculation of the cemented doublet from two lenses; evaluates the balance of aberrations in general and the calculated component behavior with temperature changes; performs comparative analysis of several similar system variants.

The spectral mathematical model of a digital color camera as an opto-electronic device was designed in the process of algorithms development for color optical correlation-extreme navigation system of unmanned aerial vehicles. The model includes the relative spectral camera sensitivity for three color channels (“red”, “green” and “blue”) and the photosensitive cell charge accumulation calibration model. Both models were successfully developed and described in the earlier publications. This paper presents integral validation of these components as a mathematical model of the device for the use in optical correlation- extreme navigation systems image processing. The additive error of such model should be less than 15–20% of the dynamic measurement range. During the experiment, a sample of 24 reference objects spectrograms was collected, and their photo was taken by the studied camera under constant lighting conditions. The decoded color coordinates of the “raw” photo information averaged for each object and reduced to the linear scale with the radiometric calibration model were used as the reliable data generated by the camera. The spectrograms processed by the spectral sensitivity model were used as the output values of its mathematical model. The determination coefficient R2 was used as a mathematical model quality metric. Its value was equal to 0.98 in the worst case (for the “blue” color channel), and the additive error distribution appeared to be close to normal. Hence the conclusion can be drawn that the model explains data variability under the impact of random factors as reliable as possible with the use of a single independent variable. The average additive error in the unit dynamic range of measurements was equal to 0.014 with a standard deviation of 0.029. Such parameters meet the advanced requirements and prove that the developed mathematical model validation is successful. Applying the developed model makes it possible to correct the color of the current images according to light spectra while the photo is taken or synthesize images of objects in the ready sample photographs of the area. The supplement of the model by spectral characteristics of the atmosphere radiation absorption and scattering gives the possibility to assess the impact of these factors on the imaging process in color optical correlation-extreme navigation systems.  

Subject of Research. The paper presents research results on the impact of the optical proximity effect, well-known in traditional photolithography, on the quality of images reconstructed using computer-generated phase modulated Fresnel holograms. Method. The study was carried out through mathematical modeling of real physical processes of synthesis and reconstruction of holograms of various structure binary transparencies in the virtual space. Each of the transparencies was examined in two versions: in the first one, it was illuminated in phase, and in the second one, the radiation incident on its neighboring elements was out of phase. Further, quality comparison of the reconstructed images was carried out. A criterion for the quality estimation of reconstructed image was expressed in terms of a number of gradations in the threshold processing of this image, in which the intensity distribution in the reconstructed image would be identical to the intensity distribution in the original object. Main Results. It is established that at image reconstruction by computer-generated holograms, the method of phase compensation of proximity effect has a positive impact on the resolution in the reconstructed image. The proximity effect manifests itself most clearly when the distances between the elements of the transparency objects do not exceed one pixel, regardless of the pixel size itself and the structure of the photomask object used. Practical Relevance. We give recommendations on the practical application of the proximity effect compensation method for improving the quality of images obtained by the holographic photolithography method.

Subject of Research. The paper presents the study of existing methods for automated control of printed circuit boards. Several alternative ways are proposed; namely, three approaches are considered for object form and internal structure reconstruction. Method. Twenty-two X-rays of a metal screw taken in 7° increments were chosen for the object of study at the development stage, as well as one-dimensional and two-dimensional data sets. All reconstruction methods of object three-dimensional form and structure are based on object display. The obtained digital images are processed by computed tomography techniques. Their key point is the application of specially developed algorithms for reconstruction of an object internal structure using projection data — object digital images. The first method is based on Radon transforms implemented by special libraries (MATLAB environment). The second method of an object form and structure development consists in mathematical processing of digital image pixel data in the MATLAB environment. The third method, in a similar way to the second, is based on the image pixel processing method implemented in the C programming language program. Main Results. Comparative study of all three methods is carried out. An unprocessed reconstruction of "screw" object slices with data array of 400 × 400 pixels is obtained. It is shown that the most versatile and open method for further development is the method that involves searching of X-ray pixel data by special program on C programming language. Practical Relevance. The results of the work can be useful for professionals involved in non-destructive X-ray inspection methods and specifically for circuit-board fabrication.

Subject of Research. The paper presents a method for mobile robot localization using a particle filter (Monte-Carlo method) based on computer vision. The localization algorithm uses distinctive landmarks that are understandable to a man. Semantic information is used in the motion model with and without range data. Method. The operation principle of the modified localization algorithm lies in applying high-level semantic prompts. Instead of squeezing the floor plan into the third dimension, the three-dimensional world is convolved into a two-dimensional representation and a sample of high-level discriminatory landmarks. This approach is used to represent global localization, which relies exclusively on semantic labels present in the floor plan and extracted from RGB images. Main Results. We demonstrate that localization with segmentation of objects, based on distinctive landmarks, is an effective alternative to traditional scanning. The study is performed in a floor plan data set, and several approaches are compared in terms of qualitative and quantitative localization at room level and global localization. It is shown that semantic information complements modern methods, ensuring that errors are reduced to 35 %. Practical Relevance. We have presented a new structure of perception and localization which uses semantic data and information about distances. The new platform can be used for localization as superior to traditional algorithms based on the Monte Carlo method.

Subject of Research. The paper considers effect of ammonium sulfate, introduced at various stages of ceramic powders production, on the impurity content, morphology and degree of agglomeration of oxyhydrate powders and ceramic powders. Method. Synthesis of precursor powders was carried out by the method of reverse heterophase precipitation from chloride salts by spraying. Synchronous thermal analysis of oxyhydrate powders was carried out using differential scanning calorimetry and thermogravimetry. The content of chlorine and sulfur impurities in oxyhydrate and ceramic powders was determined by the method of energy dispersive analysis of the elemental composition. Morphology of the experimental samples was evaluated by scanning electron microscopy. Determination of the agglomeration degree for ceramic powders was carried out by the methods of X-ray phase analysis and gas adsorption of Brunauer, Emmett and Teller. Main Results. The research has shown positive effect of the ammonium sulfate usage at several stages of the ceramic powder production at once (chemical co-precipitation, washing, disaggregation). By applying an improved synthesis method, low-agglomerated (degree of agglomeration is less than 10) nanopowders with a specific surface area of 12.4 m2/g were obtained. Practical Relevance. Optical ceramics samples with the light transmission in the visible and near-IR range of more than 80% without taking into account the absorption bands of ytterbium were obtained.

Subject of Research. The paper deals with situations when two or more models trained on different but crossing datasets are associated with one object in machine learning of probabilistic graphical models. The subject of this study is the fusion of such models, represented by knowledge patterns of algebraic Bayesian network. The study is aimed at description and formalization of the ways for fusion of algebraic Bayesian networks, presented in the form of two knowledge patterns. Method. We created such fusion models that their semantics is clearly explicated by assumptions about the ratio of probabilistic semantics of the considered knowledge patterns. Main Results. We have defined and systematized the ways to fuse knowledge patterns with no generation of new network elements. The statement about the number of atoms in the resulting network and the theorem on the difficulty of maintaining its internal consistency is given and proved. An example of the two networks fusion on a sample with noise is demonstrated. At this, the theoretical distribution of the sample is specified for carrying out comparative analysis, and the sample itself is generated by the Monte Carlo method. Practical Relevance. The methods proposed in the study for algebraic Bayesian networks fusion can be used when applying two or more trained networks describing various properties of a single object. The application of these methods gives the possibility to build a complex network aggregating all accessible data about the object under study and carry out probabilistic-logic operations in it.

Subject of Research. The paper presents a technique for forming and functioning of electronic documentation management applicable for electronic files formation in open and close electronic documentation management systems. The task of automated electronic files formation in open and close electronic document management systems is solved using the field of knowledge developed on the basis of nomenclature of files, books and journals for the current year formed by applying the document list with document retention periods. Method. Mathematical apparatus of graph theory and propositional logic (predicates) is implemented in the subject area of electronic document flow forming and functioning. Electronic files formation procedure in electronic document flow system is realized through directing of developed documents to a performer, according to the characteristics that put an electronic document in compliance with a specific electronic file. Main Results. Automation of new electronic files keeping and forming is the technical result of study. In order to reach the technical result, the fields of knowledge are considered formed at the development of nomenclatures of files, books and journals in organization. For this purpose, feature space is created using the elements of graph theory and propositional logic (logic of predicates), that characterizes documents, and relevant to the particular file according to the nomenclature of files, books and journals. The result of distribution gives the possibility to make proper marks in the electronic document accounting forms and to form requisites; then the electronic document is attached to the electronic file. Within the methodology, the tree of electronic file choice was built for an electronic document attaching. An algorithm for automated generation of electronic file was developed, and its software implementation was performed. Practical Relevance. Practical relevance of the study lies in minimization of the distribution term for developed documents into electronic files by performers, realization of automatic formation of electronic files according to the given criteria and preparation for their direction to the electronic archive.

Subject of Research. The paper presents analysis of the key areas for development of digital energy and smart grids at the current moment and for the next 10 years. We perform a review of modern software and hardware solutions for the implementation of managing integrated information systems for transmission and distribution of electrical power in Russia and throughout the world. We make a survey of international trends in the digitization of power grids and energy markets. The experience of integration of intelligent digital solutions on the sites of large power grid companies is analyzed. The expert evaluation is carried out considering implementation results of integrated information management systems at the facilities of the Unified Energy System of Russia. Method. Comparative analysis of the digitization concepts for national and foreign power grid companies made it possible to identify potential points of growth for the Russian energy sector over the future of 5–10 years. Financial analysis of dynamics investments in the infrastructure of industrial Internet of things on the global and Russian markets points to an increase in the integration of digital technologies not only in the energy sector, but also in health care, mining, industrial production and agriculture. An expert evaluation of pilot operation results for digital energy projects in different countries of the world expands the range of technological innovations in the power industry. Main Results. The ecosystems from suppliers of packet products for digital energy from different countries of the world are compared in the context of the proposed solutions in the areas of digital platforms, analytical services, geolocation systems, transport monitoring, and telemetry. Comparative functionality analysis of digital platforms for smart energy of the largest world and national high-tech companies is made. Practical Relevance. The experience of applying digital transformation technologies for the tasks of power grid companies is structured. The readiness level of power grid enterprises is evaluated for the implementation of digital energy projects in Russia currently and for the next 3 years. The performed analysis points to a greater openness of energy companies to new technologies of the industrial Internet of things against the background of national economy digitization up trend. The growth of interest in packaged solutions and Russian-designed software products is noted.

Subject of Research. The paper considers the issues of providing fault-tolerance gateways in computer networks with the use of First Hop Redundancy Protocols (FHRP). The description of FHRP family protocols and simulator OMNeT++ is given. The process of simulation model creation in OMNeT++ using ANSA-INET library is described. Detailed description of HSRP algorithm is presented and researching opportunities for simulation study by OMNeT++ simulator are considered. Work Objective. The aim of the work is the study of computer network models creation with fault-tolerance gateway in OMNeT++ simulator on the HSRP protocol example. Method. The proposed approach to the study of FHRP protocols in computer networks is based on carrying out simulation experiments in simulation environment. We show development potential for computer networks based on FHRP protocols in OMNeT++ using ANSA-INET framework which contains a large library of completed network models, components and protocol implementations. The paper describes in brief the process of computer network model development and ANSA-INET framework main abilities concerning the modeling of fault-tolerance gateways. Main Results. Computer network model with routers cluster is developed. Every router works with HSRP protocol. It gives the possibility to perform a router redundancy, that is a gateway in this computer network. Simulation model of computer network with fault-tolerance gateway is developed. We present the method of developing computer network models using FHRP protocols for fault-tolerance gateway implementation. The main stages of model development and completion are described. Practical Relevance. The presented results can be used in the design of high-reliable and fault-tolerance computer networks providing continuity of service at network gateway failure. The described tools and algorithm for development of computer network models give the possibility to carry out research on gateway fault-tolerance in computer networks and create computer-aided design systems for reliable computer networks.

Subject of Research. The paper presents research on the development of the application software user interface with the use of artificial intelligence elements. A technique is created for development of adaptive application programming interfaces based on assessment of the users’ professional qualities, psychophysiological features and emotional state. The program system is developed and implemented capable of selecting the application programming interface with regard to the users’ audience and the user’s specific state. The analysis of works on this problem is carried out. As a result, it is revealed that while the user’s model and the interface prototype creation the authors were limited to assessment of computer skills and domain knowledge, but the user’s emotional state and psychophysiological features were not considered. Method. Indistinct expert system with a core in the form of the production model of knowledge representation is used for implementation of program system analytical part. The group of experts is created and ranging of users’ characteristics is implemented at a preliminary stage. The rule base of expert system production model is developed which chooses the most suitable prototype of interface template on the basis of assessment results of users’ characteristics and their emotional state. Main Results. Application of artificial intelligence methods gives the possibility to design user’s interfaces at higher qualitative level. The implemented adaptive interface provides convenient interaction of the user with a program system and reduces the number of wrong specialists’ actions. Practical Relevance. The developed program system for design of adaptive users’ interfaces can be used at application software design in various areas of interests for wide users’ audience.

Subject of Research. The paper describes a foreign language learning process based on the spaced repetition approach and also considers encountered problems. Online services and other software products applying the given approach are reviewed; advantages and disadvantages are defined. Method. Evaluation of word priority in a user’s personal dictionary is initialized by activity data on the Internet. Two queues are stored on a per-user basis: the queue of words for repeating and the queue of words for learning. The words’ priority and the intervals between them in the repetition queue are evaluated by modified formula of SuperMemo method, where memorization factor can take only predefined values. Main Results. The modification method of spaced repetition sequence based on the user’s activity on the Internet is proposed. This method tends to suppress the shortcomings of modern online services for learning foreign languages and speed up educational process. At this, actual words for learning are detected automatically and already known ones are removed from training. One of the most significant features of the given method is the overcoming of isolation of modern online educational platforms. An application server and a browser extension have been developed on the basis of the presented method.  Practical Relevance. The proposed method can be used in the other areas where human activity is associated with the necessity to memorize a large number of new terms.

The paper presents the results of an interactive device design specially conceived for viewpoints on the example of Saint Petersburg city. We describe theoretically functionality of the corresponding device. An interactive window is created that shows information on the main visible landmarks under the user’s request. Information from 81 viewpoint visitors (users) is gathered and analyzed through the “Voice of the Customer (VoC)” method. Interactive device model is developed, and it consists of a touch, a sight position sensor, a glass and a transparent screen. Interconnection with the device is proposed in the design process. The user sees a landmark he is interested in and points at it by touching the device glass with one finger. The designed device performs a number of functions: displaying images on a transparent screen, determining which tourist attraction the user is pointing to, and controlling the camera. The screen works in three modes. With the first mode, the pictures of attractions and information about city landmarks on request are displayed in different languages. The second mode provides a full view of the attractions in full size, so that the user has the opportunity to consider as many details as possible and make a few pictures available for download. The third mode provides the user with a short message containing information about the place of interest, and it can be attached to photos. Testing has shown that transparent screens can be in demand among large manufacturers. The study can become the basis for more complex works on the study of interactive communication.

The paper presents a review of pattern recognition methods in various expert decision-making systems. In particular, the methods of visual images recognition are studied. The relevance of the proposed study is that in almost all spheres of life and production computer processes huge amounts of information at high speed, using certain algorithms, but people should anyway participate in decision-making. Pattern recognition in various processes gives the possibility to achieve maximum production results. Implementation of neural networks into production processes provides for maximum production optimization. The main task for artificial intelligence is to create certain information systems with an effective level of solutions for various non-standard tasks. Considering that, neural networks make it possible to recognize images in different decision-making systems. The subject of research is a review of pattern recognition methods in expert decision-making systems. The ability of pattern recognition in the considered systems is shown. It is demonstrated that the variety and complexity of recognition tasks do not provide implementation of one universal approach to the solution. The paper proposes modified classification of pattern recognition methods and implementation of neural networks into production process of Kamaz Public Company.

Subject of Research. The paper considers actual popular voice assistants for voice control of Internet of Things devices, such as Google Cloud Speech-to-Text, Amazon Transcribe, IBM Speech-to-Text, Yandex SpeechKit. Their pros and cons are identified. Internet connection is necessary for operation of voice assistants aimed at data processing in the cloud and synchronization and control of user’s mobile devices. Voice assistants, which can operate without Internet connection, can have significant practical value. Method. Architectural model for on-site speech recognition (without the Internet) with the use of mobile devices is proposed. CMU Sphinx software is used as a base for spontaneous speech recognition system. The software uses both acoustic and speech models for spontaneous speech recognition and also translates voice commands into such ones that can be processed by the system based on OpenHab open platform for device control. The approaches to grammar and dictionary creation for speech recognition are proposed. Example of dictionary and grammar description for voice control of attached devices are given. In order to test the described approach, the demonstration stand was created based on single-board Raspberry Pi computer with Open Hab software installed. In addition, devices of the Internet of Things based on ESP8266 microcontroller were built. Main Results. Control of the Internet of Things devices and interaction with the server are implemented with the use of MQTT protocol. Testing of voice commands recognition is carried out. The possibility of practical application of the proposed approach to spontaneous speech recognition is shown. Practical Relevance. Proposed model describes and integrates into control system a significant part of the Internet of Things devices represented on market. By applying the model, it is possible to minimize or even remove the impact of external third-party services on working capacity of voice control system for the Internet of Things devices.

Subject of Research. The paper presents a study of the existing methods for identifying and comparing the features of objects used in the re-identification task of vehicle model by its image. This task is one of the most important tasks facing automated traffic control systems, and it is solved by comparing the features of the vehicle being verified with a certain set of features obtained earlier by the monitoring system. Then decision is made whether the compared samples belong to the same vehicle model or to different ones. A method is proposed for feature vectors extraction and comparison of vehicle model according to its image. The method is based on the use of convolutional neural networks. The proposed approach is compared with existing algorithms for vehicle model re-identification by the accuracy criterion. Method. The paper describes the approach for vehicle image feature vector extraction and its subsequent comparison with the reference vector for similarity examination. The approach is based on the method of feature vector extraction, using classification convolutional neural network, and on comparison criterion for feature vectors applying the estimate of coincidental features. Main Results. The proposed vehicle model verification method demonstrates accuracy comparable to modern analogous in scenarios when the testing data have characteristics that coincide with training ones (similar camera model and camera angles are used; the level of lighting and noise are similar; models of re-identifiable vehicles are contained in the dataset used for the classification network training). In case of data significantly different from the training dataset, the method shows a lower computational complexity and uses smaller size of used feature vector and demonstrates significantly higher relative accuracy of re-identification. Practical Relevance. The proposed approach is practically applicable in vehicle identification task for highly loaded traffic control systems.

Subject of Research. The paper presents a method for numerical solution of the multidimensional Thomson Problem for packing signals interpreted as vectors on the hypersphere in broadband radio communication problems. Method. The implementation of the numerical solution of the multidimensional Thomson Problem for the packing of hypersphere vectors in radio communication problems is carried out. The developed method of packing wideband radio signals is as follows: first, the vectors are packed on the hypersphere in accordance with the formulation of the Thomson Problem, then the resulting vectors are transformed into a spectrum and on its basis the resulting signals are obtained using the inverse Fourier transform. Main Results. The paper considers the mathematical apparatus of the developed method of packing vectors on the hypersphere, as well as some results of its research for convergence and stability. The paper describes the principle of the developed method implementation based on a set of vectors packed on the hypersphere and presents some research results of synthesis method for spherical packed broadband radio signals. Practical Relevance. Studies show that the practical significance of the developed method for spherical signal packaging lies in the possibility of increasing the transmission speed of information messages and improving the efficiency of frequency-time resource usage, for example, compared with orthogonal coding. The method for packaging wideband communication signals to hypersphere meets the demands of different consumers deciding between speed and the noise stability. The developed method provides additional design possibilities for protected communication channels by increasing the power of broadband signal ensembles with noise-like character.

Subject of Research. The paper presents analysis of specific character of the operators’ activity evaluation in design process of information systems and technologies. We consider the peculiarities of the approaches used in accordance with the regulatory and technical documents to assess the stereotype coefficients and the logical complexity of activity algorithms. The methods used for assessment of the stereotype coefficients and the logical complexity of activity algorithms have a number of shortcomings that do not enable designers to apply these methods and complicate significantly the design and creation process of modern different- purpose human-machine complexes. Method. A novel approach was developed for assessment of stereotype coefficients and logical complexity of activity algorithms at the early stages of complex information system design, based on simplifying the assessment procedure. Main Results. The advantages of applying this approach in practice are shown. The proposed approach is a tool for an information system developer and simplifies his design activity to a large extent. In addition, we propose such presentation of dependencies that it makes easier the understanding of the obtained intermediate and final estimates. The approach forms the basis of the designed information module for developer’s activity support in solving problems related to the evaluation of the operators’ activity algorithms in creation of different-purpose complex information systems and complexes. Practical Relevance. This approach can serve as a methodological basis for an automated module of information support for developers of complex man-machine complexes and information systems. The use of this module will give the possibility to improve significantly the quality of the designed complexes and systems, due to the automated multiple consecutive evaluation of various options (operators’ activity algorithms) for solving the tasks assigned to it, and also increase the efficiency of the development process itself, in particular, reducing deadlines.

Subject of Research. The paper presents the parts-making quality criteria and the method of quality determination. Research results on the relationship between production and operational indicators of product quality and the influence of operating conditions on operational performance indicators are presented. Analysis of production quality is carried out for two types of parts of the same product, limiting their service life, by the method of drawing up the quality axis. Method. A quality axis was developed for specification of the product quality and the use of its quality resource. A technique for linking parts and their resource quality to the operational performance of products is presented. The technique is a convenient tool for expressing the production quality coefficient and quality application resource for products and their elements. The ways of efficiency assurance for the use of production quality resources of products in general and their components are proposed. Criteria for reliability stability are proposed for production quality evaluation of batch of products. A quality loop is used for schematic description of the product life cycle. Main Results. A method is presented for identifying rational limiting values of the quality indicators of parts and assemblies at the design stage, as well as a rational combination of the qualities of parts and assemblies in the products during their production. It is revealed that one of the directions for ensuring high efficiency of products in general can be the rational provision and use of resources of the production qualities of their constituent parts. The studies have shown that the standards-compliant operational factors of product quality do not always reflect the change in the main technological indicator, for example, the standard deviation of a significant size that affects the quality of this product. It is accepted that quality is a combination of properties and characteristics of products, which give them the ability to satisfy the consumer’s conditioned needs. Practical Relevance. Analytical expressions and methods are given for determining the production quality coefficient for various options of the upper quality limit assurance, when the operational quality of parts is limited by the accuracy of surface dimensions. The quality coefficient for evaluation and comparison of the quality of parts is given.

Subject of Research. The paper presents the study of one of the main problems of elastic stabilization and long-term strength of the system under cyclically changing external impacts. Rotary systems have a wide range of applications: power, machine and aircraft-building industries; medicine cannot exist without equipment with rotational elements (turbines, engines, drills). One of the main problems is to ensure the system elastic stability and long-term strength during cyclically changing external impacts. Method. The paper presents a survey and comparative research for a number of analytical and numerical methods of calculating the flexural vibrations of rotating shafts. The direct analytical solution was received by the continuation method in MATLAB/MATCONT module. We also considered such approximate method as bvp4c-method, that is a MATLAB built-in function. The numerical problem was solved by the finite element method using ANSYS и COMSOL software. Main Results. For determination of the rotation critical speeds Campbell’s diagrams are plotted using a distributed model of deformable shaft described by partial differential equations with variable coefficients. This model takes into account the distribution of elastic, inertial and eccentricity properties of the system, and is applicable to any range of working frequencies. Free and forced vibrations caused by the eccentricity are studied. Practical Relevance. Considered general model and verified methods give the possibility to carry out numerical simulation of the experimental facility. The inverse problem of determining the facility element eccentricity was solved. The anisotropic support stiffness and damping were determined by experimental data and theoretical estimation. The facility sensitivity to an additional external force is researched. The frequency characteristics are built up and their comparison with the results of full-scale tests is given. The methods of the shaft vibration damping by means of controlled (active) magnetic bearings are proposed.

The paper presents the results of virtual instrument development for NI ELVIS platform, designed to carrying out research of operational amplifiers during laboratory works on electronics, circuitry engineering and other similar electro-radiotechnical disciplines in higher education institutions. In contrast to NI ELVIS software, the developed virtual instrument performs laboratory works in automated mode with a greater degree of intensity, large spectrum of possibilities and less time costs. The paper can be useful for professionals involved in software development for NI ELVIS platform and university teachers of electro-radiotechnical disciplines.

The paper presents the study of Pb2+ lead ions sorption on multilayered graphene prepared by ultrasonic destruction of natural graphite in the presence of a surfactant. The concentration of Pb2+ ions in water was measured by spectrophotometric method using xylene orange indicator. It is shown that the sorption process does not have a threshold character at low concentrations of Pb2+ ions, and when their concentration goes up, the efficiency of sorption increases. The dynamics of sorption was studied; it was shown that the sorption of lead ions reaches its maximum sorption capacity value in 10 min. of sorption process.