DOI: 10.26102/2310-6018/2023.42.3.023
The relevance of this study is due to the need to improve the efficiency of extracting key phrases and words from the Russian-language patent array. Currently, patent office experts have to analyze texts of patent applications manually in order to identify key phrases and words that are then used to search for patent counterparts. This process is time-consuming and can be error-prone. Another problem is the lack of a system similar to Google Patents but for Russian-language patents. Currently, there is no reliable and effective tool for automatic identification of key patent phrases and words in Russian-language patents. This limits the ability of experts to search and analyze patent analogues as well as to make decisions on patenting. Improving the efficiency of extracting key phrases and words from the Russian-language patent array is of great practical importance. This will reduce the time spent on the analysis of patent applications, improve the accuracy of the search for similar patents and provide more reliable patenting solutions. Such a tool will be useful for patent offices, legal consultants, engineers and researchers who work with Russian-language patents. In general, this study is conditioned by the need to improve and automate the process of analyzing patent applications, which will lead to an increase in the efficiency and accuracy of managing the Russian-language patent array and make it more accessible and user-friendly.
Keywords: patents, patent search, keyword extraction, full-text search, HDFS, apache Solr, django, keyT5
DOI: 10.26102/2310-6018/2023.42.3.013
This article presents one of the scientific results obtained by the author in the course of the dissertation research. The problem considered in the study, namely the problem of ensuring the safety of road users, is raised. It was demonstrated that in megacities the installation of the “necessary minimum set of means” is not observed in all areas, which, in turn, causes violations by road users. Existing methods for assessing and improving the safety of road users are considered, limitations are highlighted. A possible tool for solving the analyzed problem with the aid of the identified restrictions is proposed which is the rational placement of technical means of traffic organization. An algorithmic apparatus has been developed that allows predicting and recommending suitable places for installing technical means of organizing traffic on those streets where they are located either irrationally or not at all based on the Decision Tree machine learning algorithm. A proprietary method for preparing input data with a description of the stages is proposed. The use of the semantic differential method to determine the weights / importance of attributes is proposed. Testing of the developed algorithmic apparatus was carried out both using the example of the “model” and using the example of a real site. It is noted that the proposed algorithm is able to generate a large amount of input data, which will further expand the algorithm and take into account even more various factors. It is expected that the developed algorithmic apparatus will significantly minimize the number of traffic accidents. It is assumed that the scientific results obtained in the research will allow a comprehensive assessment of the problems of organizing traffic in existing built-up areas or areas planned for development.
Keywords: technical means of traffic management, algorithmic apparatus, method, semantic differential, decision tree machine learning algorithm
DOI: 10.26102/2310-6018/2023.42.3.012
Agricultural administration in the context of the digital transformation of the economy is becoming more important when ensuring the competitive advantages of our country, especially taking into account the challenges of the modern geopolitical situation. The introduction of various kinds of innovations requires prompt actions in order to facilitate the development of domestic technical, technological and information products. The article deals with the issue of automation of decision support in the management of agriculture subsystems by means of a developed software product with adaptive characteristics that does not require additional digital and qualification resources. Methods of system analysis, logical approach and synthesis, optimization, algorithmization, etc., were used. Official statistical data were used, which made it possible to present the dynamics of a number of indicators (acreage and yield of fodder crops, number of cows and milk production, etc.) of agricultural production in Russia for the period 2017–2021. The conclusion is made about the intensification of production activities in the field of dairy cattle breeding. Special attention is paid to the development of algorithms and their software implementation with a view to adjusting the diet of dairy cows with consideration to scientifically based requirements, breed restrictions, norms, etc. Flowcharts for designing a user interface and functions for calculating the required amount of minerals, algorithms for calculating energy and protein requirements are given. Developed in Python, the program takes into account the selected parameters for calculating the productive feeding ration of cows and is an integral part of the intellectual system being developed. By means of simulation, it helps to choose the most suitable values of output parameters for their further use in the form of numerical restrictions when solving the problem of minimizing the cost of the feeding ration by linear programming methods. The program has a universal character regarding the introduction and use by agricultural producers, provides automation of the decision support system and does not require additional time-consuming training of decision makers who aim to achieve the efficiency of domestic agriculture performance.
Keywords: algorithm development, optimization problems, agricultural administration, decision support system, dairy cattle breeding, feeding ration, decision-maker, flowchart, program
DOI: 10.26102/2310-6018/2023.42.3.027
The article examines the problem of collecting time series data by AIOps system for monitoring the IT infrastructure with subsequent processing of the received data in real time. The relevance of the study is due to the growing interest in systems of this class on the part of large enterprises and organizations with a high degree of production process digitalization. In its turn, the organization of the process of collecting such information is conditioned by a number of features: firstly, software modules must be designed taking into account a significant load (collection and processing of about 10 million metrics per minute); secondly, end devices are not often used to collect data, other monitoring systems are employed instead. It is also required to consider the current state of the IT infrastructure characterized by its dynamism caused by the development and widespread implementation of hardware virtualization technologies, application containerization and automated configuration management. Based on a comparison of approaches to the collection and processing of time series data implemented in various monitoring tools, the paper concludes that the application and development of the Prometheus approach in AIOps monitoring systems is promising. The authors offer their own version of the adaptation and development of this approach. Distinctive features of the proposed option are a multi-status model of thresholds with a lifetime as well as the indirect establishment of links between objects in the resource-service model and the collected metric information, which helps to implement the functionality required by enterprises for collecting and processing metrics for an AIOps monitoring system under the conditions of high load and dynamism of modern IT infrastructure. In conclusion, the results of the developed software module preliminary testing are presented, and the possibility of using the approach proposed by the authors to implement the function of controlling the degree of monitoring object coverage is underscored. Currently, the described version of the architecture is used in the commercial software product "MONQ" and is being tested in several key Russian enterprises.
Keywords: monitoring system, time series, IT service, resource-service model, service management system, AIOps, big data
DOI: 10.26102/2310-6018/2023.43.4.020
Radar signal scatterers (space, air, ground and water-based radar targets) and electromagnetic wave energy converters (spatial light modulators, means of reducing visibility in the radio wave range, antenna devices in the ultra-high frequency wave range) have complex geometry and large electrical dimensions and also contain absorbing and nonlinear elements. The analysis and synthesis of this electrodynamic technique based on rough knowledge of the physical processes occurring in these objects can cause significant and difficult-to-control errors in the assessment of their main characteristics, which change rapidly with changes in frequency, type of polarization and angle of incidence of electromagnetic waves. This paper examines a methodological approach aimed at evaluating and optimizing the scattering characteristics of electromagnetic waves that occur when electromagnetic fields interact with electrodynamic structures containing dielectric inclusions. To calculate these characteristics, the method of integral equations is used, and a genetic algorithm is employed to optimize them. The results of the study demonstrate the efficiency of the proposed approaches. The methodological approach considered in the paper can be used to improve the electromagnetic compatibility of devices, reduce their radar visibility.
Keywords: modeling, optimization, electromagnetic wave scattering, integral equation, genetic algorithm, radio communication
DOI: 10.26102/2310-6018/2023.42.3.022
The article examines the mechanisms of intercomponent interaction in multi-agent systems. The paper discusses various approaches to messaging between components as well as the advantages and disadvantages of each of them. The key problems of intercomponent interaction are identified and their solutions are proposed. Particular attention is paid to the messaging mechanism based on the message broker. The principles of the broker, its advantages and disadvantages as well as examples of use in multi-agent systems are described. The results of the study showed that the use of the message broker makes it possible to create a flexible and scalable system that can efficiently process a large number of messages and maintain high reliability in operation. The paper presents a description of the data transfer format structure between the components of a multi-agent system. Message routing schemes within the system using a message broker are shown. The configuration for the implementation of the intercomponent interaction schemes is described. A mechanism for encoding messages based on tag keys is proposed, which enables their identification for further processing by software agents. This approach can be useful in the design and development of various multi-agent systems, where it is necessary to exchange messages between different software agents.
Keywords: multi-agent system, message broker, data format, JSON, rabbitMQ, MAS, coding
DOI: 10.26102/2310-6018/2023.43.4.018
The article describes the method for calculating the influence of convection on heat exchange in heat exchangers (HE) with spirally wound tubes and also presents a model that implements this object ignoring heat losses to the atmosphere. Information about the calculation code, its thermal-hydraulic blocks is given, and the necessary equations are proposed to identify the influence of free and forced convection on heat transfer in SimInTech dynamic modeling environment. Prior to the study, the calculation model was verified, where the relative error was 1.3 %, which is acceptable for this model. After successful verification, calculations were performed for the heat exchanger within the design limits and beyond its boundaries. Following on from the findings, it can be concluded that the speed of the medium at which free convection does not affect the efficiency of the heat exchanger, where 324 tubes is 1.08 m/s; for TO with 93 tubes is 1.25 m/s. Subsequently, a recommendation was developed for the use of shell-and-tube heat exchangers with spiral wound tubes: in order to guarantee effective heat transfer and minimize the impact of free and forced convection, designers should strive to maintain an average flow velocity in the heat exchanger tubes of at least 1.0 m/s; if it is impossible to maintain the speed, then it is necessary to take into account the influence and correctly position the heat exchanger so that the directions of forced and free convection coincide.
Keywords: convection, equation, computational modeling, hydraulic channel, volume, temperature, flow rate, average velocity, heat transfer
DOI: 10.26102/2310-6018/2023.43.4.005
Underwater visible light communication (UVLC) has become a promising wireless signaling approach towards the 5G and 5G beyond (5GB) wireless networks. The depth-dependent photophysical characteristics of water such as pressure, density, temperature, and salinity fluctuations lead to the changes in the refraction index and turbulence of water. The channel turbulence is a bottleneck for optical signaling in aqueous mediums, especially in oceans; it also causes malfunctions in transceivers because of signal bias or pointing error. The paper examines the performance of the reflecting node as part of underwater optical communication system operating in visible light. Based on the experimental data obtained in the Southern Indian Ocean, the outage outcomes and bit-error-rate (BER) performances are considered. The performance metrics for the proposed system model are obtained under weak-turbulence channel conditions within Pulse-Amplitude Modulation (PAM) scheme. Additionally, the authors analytically present the closed-form expression for outage probability and a tight asymptotic expression for BER performance at high signal-to-noise (SNR) ratio that offers helpful insights into the influence of the medium on channel parameters and the system as a whole. The simulation results demonstrate operational capacity of the underwater communication system model.
Keywords: underwater wireless communication (UWC), underwater visible light communication (UVLC), underwater reflecting communication, underwater weak-turbulence, diver to diver communication (D2D), reflective semiconductor optical amplifier (RSOA)
DOI: 10.26102/2310-6018/2023.43.4.008
When receiving images of ground or air objects in active or passive location systems based on millimeter-wave radar stations, sequential scanning of the viewing area is carried out. After passing the primary processing path, the received signals are translated into the corresponding radio images. An increase in the resolution of the radar image is achieved by means of its algorithmic processing with the involvement of optimal methods for solving the inverse problem of image restoration. In this paper, the object is considered as a set of independent sources. Restoration of the amplitude and phase of such sources is analyzed. The scheme of information processing in the information system is given. The conditions under which it is possible to restore the phase in the radar image are determined. An image recovery algorithm is presented. In the algorithm, the correlation integral, which includes two indices, shows what relationship exists between the energy characteristics of local sources and their coordinates. The results of restoring several sources with the specified initial data are shown. In addition, the results are presented when there is one index in the correlation integral; in that case, the image is restored to one of the axes. The results of the research can be used in the restoration of various radio images.
Keywords: modeling, image restoration, radio wave scattering, electrodynamics, radar
DOI: 10.26102/2310-6018/2023.42.3.017
Analysis of the technical aspects of augmented reality systems (AR systems) for the rehabilitation of patients with impaired balance function is an important issue in medical practice. This study is an analysis of research on the use of AR systems for rehabilitating patients with balance problems. The study covered and analyzed 31 articles published between 2018 and 2023 that used various AR systems to rehabilitate patients with balance problems. The technical characteristics of AR systems were considered such as the type of devices used, functionality, accessibility, usability and effectiveness in the rehabilitation process. The results of the review showed that AR systems can be effective in the rehabilitation of patients with balance disorders, especially when traditional therapies are limited. Some of the systems can be used at home, which can reduce the need for hospital visits and reduce treatment costs. However, many of the AR systems still require improvements to enhance accuracy and usability as well as to improve accessibility for a wide range of patients. Therefore, AR systems are a promising tool in the rehabilitation of patients with balance disorder; however, in order to increase their effectiveness, the option of using AR systems together with other rehabilitation devices, e.g. with force platforms, should be considered.
Keywords: augmented reality, rehabilitation, equilibrium, balance
DOI: 10.26102/2310-6018/2023.41.2.029
The article is devoted to the comparative analysis of the state of the organizational culture at the regional machine-building plants and, based on that, the algorithmization of the optimal selection of an action plan for its improvement. It is shown that the possibilities of improving the corporate culture are determined by the degree of its influence on efficiency increase of various aspects of enterprise activity. On the other hand, the importance of the influence of socio-economic factors on the state of the corporate culture is highlighted. It is proposed to improve it through a combination of activities with reference to a set of features with unsatisfactory marks. Expert judgement has traditionally been used for this purpose. The possibility of combining expert and formalized assessments using an optimization approach is being considered. The phasing of integration of expert assessment and optimization selection has been substantiated. The information basis are expert assessments of the influence of socio-economic factors on the enterprise corporate culture. They help to identify the signs of unsatisfactory perceptions and form an action plan aimed at improving the corporate culture. Based on the results of the expert assessment on the sensitivity of the positive change of these features depending on the resource allocation of each activity, the article offers an optimization model of linear Boolean programming, which provides an optimal solution. Implementation of the optimization approach by means of the comparative analysis of the state of the corporate culture at the regional machine-building plants was considered, which helped to choose an action plan for its improvement.
Keywords: corporate culture, machine building plants, expert assessment, optimization
DOI: 10.26102/2310-6018/2023.42.3.008
The article considers the issues of using new modern data-measuring system components with improved metrological parameters for diagnosing electrical circuit informative parameters. Development and design results of the data-measuring system that provides an ability to measure the entire set of electric power parameters within a time frame shorter than the input signal period are given. The system is based on the method of informative parameters definition by instantaneous voltage and current values of input and additional signals simultaneously measured once per period. Structural and functional diagrams of system components, the structure of command frames, answer frames and data frames, the choice of electronic component base are presented. The considered data-measuring system can be used in technological process management systems for controlling and testing electrical circuits and appliances. An electrical circuit has been developed that makes it possible to implement the operation logic and exchange protocols for facilitating data-measuring system part interaction which includes the use of Serial Peripheral Interface for data transfer. A measurement error estimation due to the input signal difference from the harmonic model is calculated with the method of estimating the error of the parameter measurement results as a function with approximately given arguments and with an error corresponding to the input signal difference from the model.
Keywords: data-measuring system, all-purpose measuring converters, additional values, instantaneous values, phase-shifting units, serial peripheral interface, synchronous data transfer format
DOI: 10.26102/2310-6018/2023.42.3.007
The economic indicators of any online store directly depend on the quality of product content. The acquisition of such content is often automated, but there is no single data exchange format on the market yet. As a result, companies spend a lot of resources integrating with various content suppliers and consumers. The author of the article proposes a format for process standardization taking into consideration the features of all types of e-commerce market participants. The format is based on the experience of developing a technological platform for a large online store and its integration with partners. The features of various market segments, types of goods, statistical data, existing exchange formats, international standards, market development trends are accounted for. The format is designed so that any market representative can start using it by means of the converter modules based on reading the required speed of commodity consumption detail without major modifications inside the access system. Such standardization will help to cut costs for market participants while integrating mutually, quickly distribute quality content, verify it, reduce the number of errors. This may lead to increased competition as small market participants will have equal access to data. Ultimately, all of this will enable venders offer their clients higher quality services and reduced prices.
Keywords: product content, database, content analytics, content error control, quality management, product card, electronic product passport, e-commerce, content transfer
DOI: 10.26102/2310-6018/2023.42.3.010
Nowadays, modeling the flow of a medium in channels of complex shape is impossible without the use of numerical methods. The complexity of the form should be understood as the impossibility of a formulaic assignment of a function that would describe the change in the shape and area of the flow living section. Nevertheless, channels of complex shape are of interest for practical use in various fields of industry. A special case of such a channel is a hydraulic diode. The main purpose of the paper is the computational modeling of the flow of the medium in a hydraulic diode at elevated parameters of the medium by means of finite element methods. The relevance of the research lies in the absence of experimental studies and examples of the operation of hydraulic diodes at elevated environmental parameters. In this paper, a hydraulic diode is modeled according to the schematics by physicist Nikola Tesla. The parameters of the medium were set as follows: pressure 16 MPa, temperature 298 °C. As evidenced by the results of calculations, the ratio of hydraulic resistances at different directions of the medium flow was 19–23. It was found that the hydraulic diode is not applicable as a check valve in technological systems since it is not able to completely block the return flow. It was also demonstrated that the hydraulic diode is physically more effective than classical leak limiters because it has a jet reaction force in the "small leak" mode of 24.5 kN versus 220 kN of the closest classical leak limiter in terms of parameters. The results of the research indicate the complex nature of the efficiency of hydraulic diodes. They also made it possible to estimate the parameters and nature of the flow of the medium in channels of complex shape with increased parameters of the medium. They can be used to optimize future calculations and modeling of hydraulic diodes for various technological systems.
Keywords: hydraulic diode, diodicity, tesla valve, jet reaction force, insert-leak limiter
DOI: 10.26102/2310-6018/2023.42.3.025
Underwater radio communication is necessary for the exchange of information with various objects that are under water, especially at great depth. In addition, the development of radio oceanography has made it possible to carry out remote monitoring over large areas of the World Ocean. The effectiveness of radar measurements will be greatly influenced if various processes that affect the interaction of radio waves with the sea surface is accounted for. To achieve this, it is necessary to develop various models. This paper examines the problem of electromagnetic wave propagation through the interface of two media: air and sea water. Models of reflection and refraction of an electromagnetic wave are presented. Different cases of polarization are considered. Properties of water found in seas and oceans are analyzed. It is shown how the dielectric permittivity of water depends on such characteristics as salinity and temperature. The salinity values of the Atlantic, Pacific and Indian Oceans are given. The case of an ultra-long wave falling on the boundary between air and water was regarded. The refractive coefficients of the electromagnetic wave were calculated depending on the angle of its initial propagation at given values of salinity and temperature.
Keywords: radio wave propagation, communication, refractive index, electrodynamics
DOI: 10.26102/2310-6018/2023.42.3.026
In 2023, changes to the admissions procedure came into force which affected enrollment in educational programs of higher education – bachelor's programs, specialty programs, master's programs for the academic year 2023/2024. The main innovation of the future admission campaign is the enrollment of applicants based on priorities. By prioritization, the applicant demonstrates his or her desire to be enrolled in specific fields of study in a particular order. The authors concluded that there is a problem associated with the lack of an algorithm that helps to automatically determine the highest priorities of the applicant at each stage of enrollment. Therefore, the purpose of the study is indicated – to develop an appropriate algorithm. The Gale-Shapley algorithm and its scope are considered – in particular, the possibility of using it to stable matching between applicants and competition groups. It was concluded that this algorithm cannot be employed by educational organizations of higher education in the 2023 admissions campaign due to the existing assumptions in its operation. We have proposed our own methods for solving the problem of determining the highest priorities according to the approved admission rules for the academic year 2023/2024. The article presents a mathematical model of the problem and the computational part of a computer program using Python programming language. The algorithm will be tested at Admiral Makarov State University Maritime and Inland Shipping during the admission campaign in 2023. The materials of the article are of practical value for the admission commissions of educational organizations.
Keywords: education, admissions office, enrollee, highest priority, enrollment, algorithm, stable matchings
DOI: 10.26102/2310-6018/2024.44.1.030
The increasing scope of application of mobile technologies and devices as elements of distributed systems to enhance the efficiency and convenience of access to various information systems and digital services has made it necessary to improve methods and mechanisms for information protection and information security. One of the main security mechanisms is access control. Features of traditional (discretionary and mandatory) access control model application in distributed information systems (IS) when using mobile systems (MS) as elements are analyzed. Thematically, hierarchical model is proposed as the most effective model that meets the required security policy. For this access control model, an ontological method for forming trust rights to access objects is proposed based on the use of semantic proximity metrics. When using traditional thematic hierarchical access control models, the logical information architecture of IS resources forms a thematic hierarchical classifier (categorizer). The Hasse diagram introduces order relations in the thematic classifier on the security grid to form trust-thematic powers of IS users. Constructing Hasse diagrams on a security grid that includes several security levels is a rather complex algorithmic task. When constructing trust-thematic powers of users in order to avoid uncertainty due to the incompleteness of the constructed Hasse diagram and overestimation of the granted powers when forming access rights, it is proposed to use the semantic proximity of the user access request and the thematic heading of the hierarchical classifier. An analysis of existing approaches to the formation of semantic proximity metrics has shown that proximity measures based on the hierarchy of concepts can be used as the best metric for setting the user’s trust authority.
Keywords: mobile station, access control, hierarchical thematic classification, semantic proximity, semantic distance
DOI: 10.26102/2310-6018/2023.41.2.022
In the oil and gas sector, a lot of attention is paid to the issue of improving the quality of data because poor quality can distort the presentation of the situation and eventually cause making the wrong decision. Oil production monitoring and preventive maintenance involve the collection of data from a variety of sensors that need to be correctly processed and “packaged”. Therefore, particular emphasis is given to improving the quality of the generated data in oil and gas well model fixations. Fixing oil and gas well models is the process of collecting, analyzing, and storing information about well operation parameters such as fluid, gas and oil flow rates, pressure, temperature, fluid composition, and other parameters used to optimize production processes and improve well performance. The presence of gaps in the formation of well models can significantly reduce the quality of these models, which can lead to an incomplete representation of the overall picture of well operation and decrease the accuracy of predicting its productivity. The article proposes an intelligent method of completing missing values for generating data in fixations of oil and gas well models to solve this problem. The method has been successfully tested at the oil and gas company Gazprom Neft PJSC using the data on the fluid flow rate of the wells in the Vyngapurovskoye field.
Keywords: intelligent method, completing missing values, nearest neighbor method, data quality, oil and gas well, well model fixation
DOI: 10.26102/2310-6018/2023.42.3.004
Managing the pace of production is a relevant issue for a modern enterprise. It is necessary to select cutting tools and cutting conditions according to a given schedule. Errors in the production process can lead to huge time and money costs. The main goal of this paper is to provide a flexible algorithm that will allow the user to select the optimal combination of cutting conditions in compliance to the production rate. The algorithm being developed also helps to quickly respond to errors that occur during the production process. The theoretical model shows the user the risks when using a particular pace of work. The technologist will be able to make a decision independently while taking as a basis data on the tool life and productivity. The presented algorithm is based on the control of the average chip thickness. This makes it possible to describe the theoretical “cutting pattern” for any pair of tool and workpiece material. The paper presents a comparative analysis of the algorithm and tabular values of cutting modes. Following on from this analysis, it is apparent that the representation obtained by the technique used in this paper helps to analyze in more detail the rationality of choosing certain cutting modes.
Keywords: optimal tool wear, chip thickness, feed per tooth, theoretical cutting force, specific cutting force, net cutting force
DOI: 10.26102/2310-6018/2023.41.2.021
Endometriosis is a common but poorly understood disease. From the appearance of the first symptoms to the diagnosis, it sometimes takes more than ten years. There is still no treatment that can help to recover from it completely. Computational models can help in understanding the mechanisms by which immune, hormonal and vascular disorders manifest in endometriosis and complicate treatment. The study deals with the construction and selection of signs of endometriosis risk and the formation of a mathematical model using several machine learning algorithms. In this case, an analysis of the importance of the signs is carried out, in which a subset of the signs that do not degrade the performance characteristics of the model (accuracy, speed, stability of operation) is reduced. The method which enables the selection of signs for constructing a prognostic model based on a selector containing filtering methods of sign significance for a processed data set is proposed. Voting for the inclusion of the sign is carried out by means of the majority function. The quality of sign construction and selection in the subject area of non-invasive diagnosis of endometriosis was assessed by a mathematical risk prediction model for endometriosis based on logistic regression with 30 traits. Model performance was evaluated using common machine learning metrics: accuracy, sensitivity, specificity, F1-score, and area under the ROC curve. The best result was achieved with an AUC of 0.950. The material is valuable to medical professionals in cybernetics.
Keywords: machine learning, non-invasive diagnosis, logistic regression, prediction, endometriosis
DOI: 10.26102/2310-6018/2023.41.2.031
The article considers the application of the optimization approach to ensuring efficient interaction of the components in a human-machine system of digitalization. The structure of such system is seen as a junction of ergatic elements with reference to nonergatic elements when performing a set of tasks of digital transformation. The formalized description of the two primary objectives is given, they include optimizing the number of ergatic elements involved in the support of the performance of digitalization system nonergatic elements and distributing the tasks among ergatic elements. The optimization models on a set of Boolean variables have been developed and the modifications to the algorithms of guided random search have been proposed. As the optimization criterion, a number of indicators are considered – performance, reliability and cost. The optimization model of the first objective is bicriterial. To define it, the integer values of the ergatic components that interact with the nonergatic elements in binary notation are recorded on a set of Boolean variables. The optimization problem is solved by means of guided random search managed for each iteration by changing the value of additive convolution of standard criteria values based on expert assessment of their priority ranking. Probabilistic characteristics of engagement in the search for Boolean variables are adjusted in concurrence with the development of convolution. The final solution is selected by group expert assessment. The optimization model of the second objective is created on a set of Boolean variables characterizing the engagement of the ergatic component in solving the specific problem of digitalization. At the same time, average operation time for the set of tasks in its entirety is regarded as an extreme requirement while boundary requirements are determined by the completion of each task within a single time frame using one ergatic element. Implementation of the guided random search algorithm is characterized by the awareness for multi-index representation of Boolean value variables and the means for excluding the solutions that do not comply with boundary constraints.
Keywords: digitalization, human-machine system, boolean optimization, random search, expert assessment
DOI: 10.26102/2310-6018/2023.42.3.019
Venturi nozzles have found quite wide application in various industries. The paper considers the design and operating modes of the basic leak limiter made in the form of an asymmetric Venturi nozzle which is one of the technological systems of the first circuit of the Novovoronezh NPP-2 power unit No. 1 (NPP-2006 project). Methods for modeling in the ANSYS CFX software and hardware complex using the finite element method and operating modes of the device to assess its effectiveness in emergency mode and normal operation mode are presented. The results of thermohydraulic calculations of the stationary operation mode of the leak limiter insert are given, comparison with the results according to basic calculation methods is performed. The complexity of the task being performed lies in the fact that the leak limiter is installed on the pipeline where the coolant has a temperature significantly higher than the saturation temperature consistent with the pressure of the medium into which the leakage occurs when the pipeline breaks. The section of the cylindrical neck of the minimum cross-section provides boiling of the liquid within its length, which leads to partial self-locking of the leaking coolant flow because of enabling a critical flow mode; in essence, this refers to the solution to the problem of a two-phase medium flow.
Keywords: leak limiter insert, venturi nozzle, modernization, purge, pipeline rupture, coolant leak, finite element method
DOI: 10.26102/2310-6018/2023.42.3.024
The finite element method has been known for a long time, but its active application for modeling physical processes began shortly after the development of modern computer machines. One of the advantages of such modeling is the reduction of time and financial costs compared to conventional experiments. The paper presents the results of hydraulic calculation of the design mode of a complex technological system operation by the finite element method. The calculation was performed using the thermal hydraulic CFX module of Ansys software package. At the same time, as part of the computational domain, a porous body model was employed as an alternative to direct modeling of system devices with a complex design. The object of the simulation was the cooling tower recharge system of power unit No. 1, 2 of Novovoronezh NPP-2. The test (verification) calculation showed an acceptable discrepancy with the real parameters of the system (within 15 %). According to the results of the computational analysis, the optimal number and combination of constantly operating pumps in the system were identified which achieved an increase in the consumption of the main cooling water by 30-40 % which, in turn, will reduce the accumulation of calcium carbonate on the main structural elements of cooling towers. The porous body model can be used both to predict the operating modes of equipment with complex design individually and as part of technological systems.
Keywords: complex technological systems, purging, operation, main cooling water, cooling tower, water chemistry specifications, porous body model, finite volume method
DOI: 10.26102/2310-6018/2023.42.3.005
Nowadays, increasing attention is paid to the issues of risk assessment and management, which are strongly associated with the globalization process of modern civilization. Based on the analysis and generalization of available statistical data on project risk management, it was found that less than half of the existing organizations carry out activities aimed at risk management (identification, monitoring, development and implementation of risk mitigation measures). The article considers a special case of solving the problem of risk management which consists in achieving the goal of the program at minimal cost taking into account restrictions on financing high-risk projects or on their number. It should be noted that in the existing documents on the regulation of project management processes, there is no methodological support for identifying, assessing and minimizing risks at all. In addition, there are currently no effective methods of comparative identification, analysis of interrelations and mutual influence of risk values and mechanisms for their minimization in the implementation of projects and project management. To account for the degree of project implementation risk, two objectives of forming the programs being implemented are proposed. The first objective implies identifying single-purpose projects for inclusion in the program that ensures the achievement of its goal at minimal cost with due regard for restrictions on high-risk project funding or their number. An original algorithm for solving the problem based on the branch-and-bound method with the proposed method for estimating a subset of solutions from below and an approximate heuristic algorithm using the “expense-effect” method are presented. The second objective was to reduce the cost of implementing the program by converting a number of low-risk projects to medium- and high-risk options. To solve this problem, the branch-and-bound method to obtain estimates of solutions by the network programming method was employed.
Keywords: project, program, risk, branch-and-bound method, heuristic algorithm, generalized dual problem
DOI: 10.26102/2310-6018/2023.42.3.003
The article discusses the rationale for the choice of methods and algorithms for mutual information coordination (consensus achievement) in a distributed multi-agent system used to solve the problem of information monitoring in complex technological objects. The architecture of this multi-agent system is decentralized and based on the set of intelligent monitoring agents that receive and process data from the object under control which is a part of the system within which information monitoring is performed. The purpose of the monitoring is to predict the instances of non-stationary load occurrence at the objects being monitored. A feature of the system is the presence of non-stationary load propagation time lag over the subsets of monitoring objects. The problem of predicting the instances of non-stationary load occurrence and propagation as part of an intelligent monitoring agent is solved by means of a neural network model trained using the precedents occurring at the object. To account for the propagation of non-stationary load time lag, it is proposed to perform additional training of the neural network model not only on its own data set, but also on the data sets of the nearest neighbors connected by the propagation of non-stationary load time lag which requires solving the problem of their mutual information coordination. The article discusses approaches to the selection and modification of the algorithms for the multi-agent system architecture – multicast messaging concerning the instances of non-stationary load occurrence and routing of these messages in a decentralized structure of an information monitoring system. The data structures necessary for these algorithms and protocols for the interaction of intelligent monitoring agents, which provide an increase in the speed of message delivery, are considered.
Keywords: monitoring systems, multi-agent systems, intelligent agent, consensus achievement, decentralized systems, message routing, message delivery time
DOI: 10.26102/2310-6018/2023.41.2.016
The paper considers uncertain factors that can lead to abnormal situations in the control system of the power supply system of a spacecraft. Certain factors that can be predicted as well as factors whose influence can be accounted for when designing the control system and building control algorithms are highlighted. Uncertain factors that can be predicted using the intellectualization of electric power distribution control system have been identified. Elements of the system the reliability of which can be improved by applying intelligent control system and the prediction of abnormal situations on the basis of artificial neural networks have been identified. The analysis of existing control algorithm for power supply system has been carried out. By means of the telemetry parameters used in this algorithm, selected telemetry parameters for use in the intelligent control system of the power supply system have been identified. The criterion for an emergency situation the occurrence of which must predict the artificial neural network is defined. The configurations of artificial neural networks which can be used as a foundation for intelligent control system of power supply system of a spacecraft are considered. The problem of available training data sample optimization for training the artificial neural network is regarded. Suitable methods for the optimization of neural network training in the context of the specifics of the problem are considered. A specific configuration of artificial neural network, mindful of the specifics of application and the heterogeneous nature of the training data sample, is proposed.
Keywords: spacecraft power supply systems, regulation and control equipment, neural networks, intellectualization, forecasting systems
DOI: 10.26102/2310-6018/2023.41.2.019
Improving the quality of automatic control systems is an important problem in many areas. This issue is particularly relevant in systems requiring an increased level of reliability, such as control systems for space equipment including power supply systems. Power supply systems must fully meet the need of a spacecraft in electric power required for regular flight program performance, which implies the increased requirements for its reliability and quality of its operation. The article considers functional and informational structure of spacecraft power supply systems. The principles of data exchange between the elements of regulation and control equipment with the power supply system are described and the hierarchical structure of the power supply control system elements is built. The current approaches to the automatic systems of control and management of spacecraft power supply systems are regarded. Based on these data, the algorithms of power supply system control are analyzed using the example of battery charging and discharging algorithms. The phenomena which are not accounted for when building the algorithms are considered. The means to improve the algorithms for controlling battery charging and discharging by introducing new parameters to track the degree of battery degradation are proposed, and the means of intellectualizing the algorithm are considered. A proposal is made to intellectualize the control system using a neural network trained on the spacecraft onboard telemetry.
Keywords: control algorithms, spacecraft power supply systems, regulation and control equipment, onboard computer network, control system intellectualization
DOI: 10.26102/2310-6018/2023.41.2.030
The presented results provide justification for the applicability of numerical methods for analyzing initial-boundary value problems for evolutionary differential equations with a spatial variable changing on a network (graph), i.e., on a manifold of one-dimensional continua with a scalar variable. Similar results for -dimensional spatial variables ( ) changing on a network-like -dimensional domain are still in the stage of formation due to the incomparably high level of technical complexity that naturally arises when increasing the dimensionality of the spatial variable. Confirmation of the possibility of justifying numerical methods for analyzing initial-boundary value problems for cases is provided using the results of applying computational methods to solving a test problem with a spatial variable changing on a two-dimensional network-like carrier – a two-dimensional complex-structured domain. The presented example of numerical analysis opens prospects for extending the obtained results to differential operators defined on functions with an m-dimensional carrier. To simplify the representations of difference schemes, a method of semi-discretization with respect to the time variable is used (in a sense, numerous routine costs that arise as a direct consequence of the multidimensionality of the spatial variable are leveled). The obtained results are applied in constructing and numerically analyzing mathematical models of laminar and turbulent network-like processes in applied hydrodynamics.
Keywords: differential operators on network-like domains, finite-dimensional analogues, properties of finite-dimensional analogues, difference schemes, numerical analysis
DOI: 10.26102/2310-6018/2023.41.2.014
The article discusses the use of a graphic-analytical method for evaluating and revising plans for GERT-network modeling of transport and technological cycles of unmanned aerial vehicles utilized in the precision farming system. A formal description of the model and an algorithm for searching for the optimal implementation of the UAV transport and technological cycle are proposed, which allows minimizing the costs of its implementation taking into account the characteristics of production situations that arise in the precision farming system when using the UAV. The formalization method is based on the notion of the UAV transport and technological cycle as an acyclic GERT network with a source and sinks. Since the stochastic dynamic structure of the transport-technological cycle is considered, the possibility of introducing random events during its implementation and the execution of several successive cycles is provided. At the same time, the minimum possible costs when performing these transport and technological cycles must satisfy the optimality criterion. It is suggested to switch to cost reduction by means of an iterative procedure at the optimization stage taking into account the finite number of UAV transport and technological cycle implementation stages. As a result, the decision maker, employing the decision GERT network, will be able to choose the implementation of the transport and technological cycle that minimizes costs for its implementation. The paper proposes an algorithmic procedure that ensures the choice of the best possible solution, which helps to increase the efficiency of formation, analysis and management of UAV transport and technological cycles, as it enables full consideration of the characteristics of production situations in precision farming systems using unmanned aerial vehicles.
Keywords: GERT-network, modeling, cost minimization, unmanned aerial vehicle, transport and technological cycle
DOI: 10.26102/2310-6018/2023.42.3.001
The article considers the application of the optimization approach to enterprise management using a cyber-physical system. A human-machine environment is the object of optimization. Features of interaction of nonergatic elements with the elements of physical and computational levels of cyber-physical architecture are observed. It is shown that ergatic element function allocation by the indexes of reliability and efficiency of a human-machine environment is the optimization task at the lower level. In the formalized form, the optimality requirements determine the multi-objective model by a set of alternative variables. The decision-making algorithm based on random search combined with expert assessment is offered. The capabilities of establishing the division of the total amount of ergatic OS elements between three functions at the initial stage of the search by expert way followed by the assignment of each ergatic element in the iteration mode have been considered. The optimization of a human-machine environment at the upper levels of a cyber-physical system is aimed at assigning each ergatic element to perform a specific action. The structure of the optimization model differs from the first task. The developed decision-making algorithm based on the integration of random search iteration procedure and expert assessment procedure is used for both optimization tasks. Multicriteriality is accounted for along with the iterations of probabilistic characteristic adjustment by changing the probability of engaging the criteria in the search. The models and algorithms listed above help to optimize the structure of ergatic element operation in a human-machine environment for enterprise management using a cyber-physical system.
Keywords: organizational system, management, human-machine environment, cyber-physical system, optimization