Showing papers in "Vestnik Moskovskogo gosudarstvennogo tehničeskogo universiteta in 2023"
TL;DR: In this article , a hybrid evolutionary method was proposed to solve the problems of global material optimization of the extra-large dimension, which is based on the idea of the computing resources automatic allocation between a group of self-tuning differential evolution algorithms based on coevolution and local search algorithm.
Abstract: When solving applied problems in various areas of human activity, the need appears to find the best set of parameters according to the given criterion. Usually such a problem is being formulated as a parametric optimization problem. The paper considers optimization problems represented by the black-box model. As such problems dimension grows, it becomes difficult to find a satisfactory solution for many traditional optimization approaches even with a significant increase in the number of objective function calculations. A new hybrid evolutionary method in coordinating the self-adjusting coevolution algorithms with the COSACC-LS1 local search is proposed to solve the problems of global material optimization of the extra-large dimension. COSACC-LS1 is based on the idea of the computing resources automatic allocation between a group of self-tuning differential evolution algorithms based on coevolution and local search algorithm. Effectiveness of the proposed algorithm was evaluated on 15 reference test problems from the LSGO CE 2013 set. Results of the COSACC-LS1-based algorithm were compared with a number of modern metaheuristic algorithms that were designed specifically for solving the very large-scale optimization problems and were the winners and prize-winners in the optimization competitions conducted within the framework of the IEEE CEC. With the help of numerical experiments, it is demonstrated that the proposed algorithm is better than most other popular algorithms according to the average accuracy criterion of the solution found
TL;DR: In this article , a method for generating images based on the hidden information is proposed, which guarantees possibility of both hiding and subsequent extraction of information eliminating the need to select an appropriate container.
Abstract: Due to the rapid development of information technologies, the tasks of ensuring information integrity, safety and confidentiality, as well as the possibility of guaranteed confirmation of its source, are becoming more relevant than ever. One of the possible solutions to this problem could be the steganographic methods, which allow both hiding the fact of information transfer and imperceptibly adding the useful data. Scientific literature describes a large number of steganographic algorithms. However, only insignificant number of works is devoted to the data hiding methods using the neural networks, and even less are devoted to generating containers for them. A method for generating images based on the hidden information is proposed, which guarantees possibility of both hiding and subsequent extraction of information eliminating the need to select an appropriate container. As part of the method, an algorithm was developed that included description of the stages of input data preprocessing, transformation into the container image and extraction of the hidden information. Examples of the proposed method operation are provided. The method could serve both as a steganographic algorithm for hiding information and as the algorithm for adding information in the form of watermarks
TL;DR: In this paper , the authors presented experimental research of the diffraction patterns of radiation reflected from the retroreflector spherical system of glass geodesic passive satellites of the Blitz-type created at the JSC "SPC "PSI".
Abstract: The paper presents experimental research of the diffraction patterns of radiation reflected from the retroreflector spherical system of glass geodesic passive satellites of the Blitz-type created at the JSC "SPC "PSI". The Blitz-type satellites are used in the interests of the GLONASS for high-precision laser ranging and are a set of concentric layers with different refractive indices. The purpose of the study was to determine based on the experiment data the effective beam diameter forming the reflected radiation diffraction pattern in the far zone, which value was required to calculate the satellite energy parameter, i.e., the effective scattering surface. The effective beam diameter dimension for the indicated retroreflector spherical system was determined experimentally by installing various diaphragms that limited the radiation beam size. It is shown that alterations in the diffraction pattern in the far field started, when the diaphragm opening was smaller than the effective diameter. Experimental and calculated values of the satellite’s equivalent scattering surface were comparatively analyzed. According to the experimental results, the diffraction pattern is determined by the central zone of the retroreflector spherical system, where wave aberrations are less than a certain limit corresponding to the Fresnel diffraction with several active first zones
TL;DR: In this paper , the authors analyzed the data delivery routes in the wireless self-organizing networks, which basis (nodes) were the unmanned aerial vehicles (UAVs).
Abstract: Currently, one of the promising areas in the development of network technologies is the wireless self-organizing networks based on the unmanned aerial vehicles, i.e., FANET (Flying Ad-Hoc Networks), which most important task in the course of their operation lies in organizing the effective data exchange. The distinctive properties of wireless self-organizing networks with altering topology are leading to the fact that technical solutions and methods of determination of the data delivery routes used in telecommunication networks with the traditional fixed architecture turn out to be inefficient in the special FANET networks and are not able to provide the required performance. At the same time, wireless self-organizing networks based on the unmanned aerial vehicles possess their own techniques used in data routing, which are subject to the requirements that take into account characteristic differences inherent in the networks of this type, including high mobility and low density of the nodes, dynamic and frequent topology alterations. Features and methods for determining data delivery routes were analyzed in the wireless self-organizing networks, which basis (nodes) were the unmanned aerial vehicles
TL;DR: In this article , the authors used four Sentinel 2 MSI satellite images received during the 2020 and 21 dry seasons to evaluate alteration in the water surface area of Lake Dankia in the Lam Dong Province of the Vietnam Central Highlands.
Abstract: Vietnam in recent years, especially in the Central Highlands and the South Central region, is experiencing severe droughts due to global climate change, depletion of the surface water resources and intensive agricultural production. The study used four Sentinel 2 MSI satellite images received during the 2020--2021 dry seasons to evaluate alteration in the water surface area of Lake Dankia in the Lam Dong Province of the Vietnam Central Highlands. Optical green channel (channel 3) and shortwave infrared channel (channel 11) of the Sentinel 2 images were used to calculate the modified normalized difference water index MNDWI and to decipher the land--water boundary by the thresholding method. The obtained results demonstrated that the Lake Dankia area at the dry season end (March 18. 2021) decreased by 86.46 hectares compared to November 18. 2020 (dry season start), which was 31.7 % of the original lake area. This study shows that the Sentinel 2 MSI satellite images could be effectively used to monitor alterations in the surface water area and provide valuable input information for models to assess the drought impact on water resources in the areas
TL;DR: In this paper , a method for determining the soil deformation index provides for a smooth indentation of a hemispherical tip into the soil or earth with simultaneous fixation of its immersion depth into the ground and of the force required in penetrating to this depth.
Abstract: The paper considers development of the new area in agricultural engineering, i.e., bionics. The purpose of the work is to elaborate methodology and technical means for determining the soil deformation index as a new characteristic of its physical and mechanical properties, which makes it possible to pass directly from the processed materials deformation properties to the shape of the working surfaces of machines created in similarity to the living dorbeetle organisms. The soil deformation index is the deformer area per unit of critical pressure on the soil. When describing the soil behavior in the deformation process, the paper proposes to use this indicator in the rheological models. The method for determining the soil deformation index provides for a smooth indentation of a hemispherical tip into the soil or earth with simultaneous fixation of its immersion depth into the soil and of the force required in penetrating to this depth. Registration of these parameters is possible both on paper in the form of a diagram and electronically in the digital form. A device for the soil deformation index determination is considered, it includes a laboratory unit with the hydraulic drive, a microscope-based unit for bionic research and a device for working in the field
TL;DR: In this article , the authors proposed methodological approaches to develop a human-machine interface for the specialized software supporting operator activities of industrial facilities in emergencies, where the operator actions in the emergency were analyzed, and requirements for the operator support program interface were formulated.
Abstract: The paper proposes methodological approaches to development of a human-machine interface for the specialized software supporting operator activities of industrial facilities in emergencies. As an example, development of a system is considered to support activities of the oil refinery operators in eliminating various failures and their consequences in accordance with the adopted regulations of the accident elimination plan. Features of the operator actions in the emergency were analyzed, and requirements for the operator support program interface were formulated. The proposed approach is based on introduction of design patterns for human-machine interfaces in the safety-critical systems. Main patterns were analyzed, and recommendations were given on the use of specific patterns in creating a software interface to support the operator actions. Results of the experimental study of possibilities of the proposed software practical application are presented showing significant reduction in the time spent by the operator on actions to execute the emergency response plan requirements and decrease the number of errors. This confirms effectiveness of the developed methodology in practice. As the area for further improvement of the industrial facilities operator actions, it is advisable to consider methods for estimating the operator state according to the data obtained from heterogeneous information channels including speech, analysis of the number of blinks, evaluation of emotions, analysis of the head tilt, direction of gaze and others using the convolutional neural networks of deep learning
TL;DR: In this article , the authors investigated electrical parameters and characteristics of the pulsed xenon lamp ultraviolet radiation with a U-shaped plasma channel and caprod current leads, and established that the possible factors leading to a decrease in the current density and intensity of the UV radiation included the modes of electrical supply and evaporation of the quartz shell limiting the discharge.
Abstract: The paper presents main results of investigating electrical parameters and characteristics of the pulsed xenon lamp ultraviolet radiation with a U-shaped plasma channel and caprod current leads. The gas-discharge lamp design feature suggests presence of the ballast transelectrode volumes contributing to the xenon escape from the discharge and the radiation acting from one part of the U-shaped plasma channel on the other. Literature sources devoted to the specified phenomena were analyzed. Factors influencing the xenon plasma thermophysical state were established. Due to the lack of techniques for registering the pulsed radiation in a narrow spectral range of 200--300 nm, measurement techniques and investigation hardware were considered in detail. The time interval for establishing the gas-dynamic equilibrium in a pulsed xenon lamp in the process of its entry into the nominal operating mode was determined by calculation and experiment. Studies of the Vt transelectrode volume effect on characteristics of the pulsed xenon plasma were carried out in the range of 0.16 < Vt /Vi < 0.3. It was established that the possible factors leading to a decrease in the current density and intensity of the UV radiation included the modes of electrical supply and evaporation of the quartz shell limiting the discharge. It was shown that self-radiation return in plasma contributed to an increase in the current density of the pulsed xenon lamp
TL;DR: In this paper , the authors presented a hybrid method of risk analysis in the complex systems predicting the possible accident development associated with the social systems, as well as recommendations in prevention of such accidents.
Abstract: The paper presents a hybrid method of risk analysis in the complex systems predicting the possible accident development associated with the social systems, as well as recommendations in prevention of such accidents. The proposed method in order to determine operational state of a complex system and endow it with additional ability to withstand failures combines system dynamics models (to help in identifying interactions of the elements of the system under study in dynamics), event and failure tree models (used to simulate the risk scenario evolution) and artificial neural networks. The hybrid risk management methodology in sociotechnical systems is based on combining capabilities of different artificial intelligence technologies and makes it possible to introduce advantages of several technologies by integrating them. Six stages of research carried out within the framework of hybrid technique are presented, as well as mathematical description of the neural network model. Effectiveness of the proposed methodology was tested using three implemented software products. On the example of a construction company and using the developed original software package, accident scenarios were simulated, and a neural net-work was built to predict risks and determine the company operation status. Simulation results are provided
TL;DR: In this article , the authors investigated the impact of downtime on the performance of pilot production in the manufacturing process of the devices manufacturing prototypes and revealed a new characteristic of downtime associated with errors in the design of the products and the preparation of technical documentation for their manufacture.
Abstract: The paper substantiates relevance of reducing downtime as an integral part of the enterprise profitability and competitiveness in modern economic conditions. Downtime of the pilot production, which is one of the main stages of the innovation process at the industrial enterprise, was analyzed. Problems of management, organization and planning in pilot production were revealed. Main stages of the devices manufacturing prototypes were considered. A new characteristic feature of pilot production was revealed, i.e., random production equipment downtime associated with errors in design of the products and preparation of technical documentation for their manufacture. Characteristics of random production equipment downtime was studied, which made it possible to prove their Poisson properties. Specific factors of downtime characterizing only the processes of creating the device prototypes were determined. Relationship between specific factors and general downtime was studied to find the factor most significant in terms of the amount of losses. Presence of such a factor leads to revision of existing and formation of fundamentally new approaches in creating technological chains in production of the experimental or prototype samples. Pilot production as part of the most instruments manufacturing enterprises determines high practical significance of the analysis performed
TL;DR: In this paper , a general approach to solving the terminal optimal control problem of evolutionary computational algorithms is presented, where a hybrid evolutionary algorithm based on a combination of several evolutionary algorithms is considered.
Abstract: The present article considers the problem of numerical solution of the terminal optimal control problem. The general statement of the terminal optimal control problem and a brief overview of its solving methods are presented. With a direct approach and reduction of the optimal control problem to the finite-dimensional optimization problem, the target functional on the space of desired parameters, regardless of the type of approximation of the control function, may not have the unimodal property. Therefore, it is advisable to use evolutionary algorithms to solve the problem. A general approach to solving the terminal optimal control problem of evolutionary computational algorithms is presented. The paper presents a description of some evolutionary algorithms that were selected as the most effective for solving the optimal control problem. A hybrid evolutionary algorithm based on a combination of several evolutionary algorithms is considered. The computational experiment considers the terminal optimal control problems, for which optimal solutions were found by known classical numerical methods that use the gradient of the target functionality when searching. Comparison of the results obtained by classical and evolutionary methods by functional values and computational costs allows us to conclude that evolutionary algorithms are able to effectively solve the terminal optimal control problems
TL;DR: In this article , the authors considered general problems of information systems interoperability, approaches to its analysis and support, and basic requirements for ensuring the technical system interoperability are provided, and analyzed approaches to formation of the information interaction models in accordance with the level of conceptual interoperability model and the reference interoperability models.
Abstract: The paper considers general problems of information systems interoperability, approaches to its analysis and support. Basic requirements for ensuring the technical systems interoperability are provided. Approaches are analyzed to formation of the information interaction models in accordance with the level of conceptual interoperability model and the reference interoperability model. The concept of smart work-place is introduced in relation to the Design-to-order information support, objective and tasks of the smart workplace operation are formulated. Generalized network-centric architecture of the Design-to-order unified information space is presented, which provides information support in implementation of the design and production chain. The proposed unified information space architecture includes mechanisms of automatic generation and adaptation of the design data basic and domain-specific models taking into account the constantly altering application conditions. In general, the proposed network-centric architecture of the Design-to-order unified information space ensures uninterrupted information interaction from the customer to separate workplaces and target processes of the product life cycle. Using these adaptive ontological models appears more preferable than introduction of the static interoperability profile, which development could be hampered by complex nature of the integrated technical product being manufactured
TL;DR: In this article , the Schottky-barrier composite two-tier FETs based on the GaN crystals in the previously developed hybrid integrated circuit design, as well as the possibility to increase power dissipation up to 200 W with using one pair of crystals and to 250 W with the two pairs.
Abstract: The paper demonstrates relevance and prospects of using the Schottky-barrier composite two-tier FETs based on the GaN crystals in the previously developed hybrid integrated circuit design, as well as the possibility to increase power dissipation up to 200 W with using one pair of crystals and to 250 W with using the two pairs. Thermal calculation results are presented proving the prospects of using the proposed hybrid integrated circuit design. Crystals of the two types GaAs and GaN are compared. Efficiency and prospects for using GaN crystals and Schottky barrier composite two-tier field-effect transistors in a hybrid integrated circuit of the microwave power amplifier could significantly improve its weight and size characteristics. Advent and use of the Schottky-barrier field-effect transistors based on the GaN crystals with the power of up to 100 W and more was temporarily solving the problem of increasing the power and improving the weight and size characteristics of the microwave amplifiers. When comparing maximum temperatures on the transistor crystal at the released power of 1 W, it was found that an increase in the thermal conductivity of the additional heat sink contributed to maximum temperature displacement from the upper crystals to the lowers and changed the heat flow direction. GaN crystals use increased the power level over the entire range of thermal conductivity of the additional heat sink materials 500--2000 W/(m · K), and the power ratio with an increase in the thermal conductivity of the additional heat sink was approximately equal to two. Prospects of using the proposed design of a hybrid integrated circuit of power amplifiers was justified
TL;DR: In this article , the authors proposed an autocollimation control method using a concentric meniscus lens with dimensions slightly exceeding the dimensions of the controlled part, based on the theory of the third-order aberrations.
Abstract: Convex aspherical surfaces are being increasingly used as elements of the high-precision optical devices for various purposes. Complexity in such surfaces manufacture is because the existing methods of their shape control with the optical accuracy of about 20--30 nm require introduction of the auxiliary reference optical elements, which dimensions are several times larger than those of the controlled part are. The paper proposes the autocollimation control method using a concentric meniscus lens with dimensions slightly exceeding the dimensions of the controlled part. Results of calculating the control circuit design parameters are presented based on the theory of the third-order aberrations. Effect of the refractive index and thickness of a concentric meniscus lens on the maximum and root-mean-square deviations of the surface shape with various requirements to concentric meniscus lens radii was considered, and the developed scheme simulation in the Zemax soft-ware was also proposed. The Fizeau interferometer optical scheme was described using a lens with the reference surface to implement the developed method. Applied research was carried out to control the secondary mirrors of the Ritchie --- Chretien telescope at the Hoa Lak Observatory (Vietnam) and of the SNAP satellite telescope