2022 № 4 Сучасні інформаційні системи

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Analysis of marсovian systems with a given set of selected states
(Національний технічний університет "Харківський політехнічний інститут", 2022) Raskin, Lev; Sukhomlyn, Larysa; Korsun, Roman
Analysis of stationary Marcovian systems is traditionally performed using systems of linear Kolmogorov differential equations. Such systems make it possible to determine the probability of the analyzed system being in each of its possible states at an arbitrary time. This standard task becomes more complicated if the set of possible states of systems is heterogeneous and some special subset can be distinguished from it, in accordance with the specifics of the system functioning. Subject of the study is technology development for such systems analysis. In accordance with this, the purpose of the work is to find the distribution law of the random duration of such a system's stay on a set of possible states until it falls into a selected subset of these states. Method for solving the problem is proposed based on splitting the entire set of possible states of the system into two subsets. The first of them contains a selected subset of states, and the second contains all the other states of the system. Now a subset of states is allocated from the second subset, from which a direct transition to the states of the first subset is possible. Next, a system of differential equations describing the transitions between the formed subsets is formed. The solution of this system of equations gives the desired result – distribution of the random duration of the system's stay until the moment of the first hit in the selected subset of states. The method allows solving a large number of practical problems, for example, in the theory of complex systems reliability with many different failure states. In particular, finding the law of the uptime duration distribution, calculating the average duration of uptime.
Application of association rules for formation of public (administrative) services portfolio
(Національний технічний університет "Харківський політехнічний інститут", 2022) Гавриленко, Олена Валеріївна; Хоменко, Олександр Миколайович; Жураковська, Оксана Сергіївна; Коган, Алла Вікторівна; Піскун, Андрій Михайлович; Халус, Олена Андріївна
The formation of complex services is carried out exclusively according to the principle of association based on a life (business) event or situation. But as practical experience shows, users often request several services at the same time, and these services are not connected by one life event. This can be seen if you analyze the statistical data on service delivery by service delivery centers. The application of intelligent data analysis allows to reveal the hidden relationship between services. Based on this, a new principle of combining services was formulated. The object of research is the process of forming a portfolio of services based on association rules. An algorithm for forming a portfolio and providing recommendations for a decision-maker has been developed. Recommendations are presented in the form of sets of services that can be included in a portfolio. The application of this principle will allow to expand the set of complex services due to new portfolios. This will simplify and improve the service delivery process for both authorities and users.
Comparative studies of methods for improving the cyber security of unmanned aerial vehicles with the built-in ADS-B system
(Національний технічний університет "Харківський політехнічний інститут", 2022) Semenov, Serhii; Zhang, Min Jian
The subject of study in the article is methods for improving the cybersecurity of unmanned aerial vehicles with an integrated ADS-B system. The aim is to analyze and compare methods for improving the cybersecurity of unmanned aerial vehicles with an embedded ADS-B system. Particular scientific tasks: analysis and comparative studies of the main types of cyber threats and methods for improving the cybersecurity of unmanned aerial vehicles with an integrated ADS-B system, the development of an appropriate taxonomy, and the development of proposals for further research. The methods used in the article are the methods of system analysis. The following research results have been obtained: a classification of cyber threats to the security of unmanned aerial vehicles with an integrated ADS-B system has been developed; a taxonomy of ADS-B message modification and injection attacks has been developed; practical UAV security metrics adapted to the presented taxonomy of cyberattacks are defined and researched; chosen most priority directions research; a generalized classification of cryptographic protection methods adapted to solve the problems of improving the security of UAVs with an integrated ADS-B system has been developed; the use of additional means of identification based on steganographic methods of data protection is proposed. Conclusions. An analysis and comparative studies have been carried out, and a generalized classification of methods for improving the cybersecurity of unmanned aerial vehicles with an integrated ADS-B system has been developed. Their advantages and disadvantages are revealed, which made it possible to determine the priority of further research and possible promising ways to solve the tasks.
Computer simulation model of a computer network with fractal traffic for testing routing algorithms
(Національний технічний університет "Харківський політехнічний інститут", 2022) Drieieva, Hanna; Meleshko, Yelyzaveta; Drieiev, Oleksandr; Mikhav, Volodymyr
The object of research in this article is simulation modeling of a computer network and the process of traffic routing. The relevance of the research is due to the importance of ensuring the quality of service in computer networks, in particular, by necessity reducing the number of lost IP-packets at high traffic intensity values. Determining the routing of traffic packets is a complex process and is based on various indicators or combinations of indicators. If the routing process takes place in a dynamic mode, then the complexity of the route calculation increases, in this case, one of the tools for research and comparison of different routing algorithms can be a computer simulation model of a computer network. The goal of the work is the development and research of a computer simulation model of a computer network for testing traffic routing algorithms. The tasks: to develop computer simulation model of a computer network to generate the network structure and simulate the traffic distribution process with the ability to test different routing algorithms. Research methods: theory of computer networks, theory of fractal analysis, object-oriented programming, theory of algorithms and data structures, theory of complex networks, theory of Markov processes. Conclusions. The paper investigated the basic principles of traffic routing in computer networks. A simulation model of a computer network for testing traffic routing algorithms has been developed. A method based on the theory of complex networks has been developed to generate the structure of a computer network. Theory of fractal analysis and Markov processes are used for traffic generation. A series of experiments was conducted on a developed model to determine how different fractal dimensions of traffic at high traffic intensity values affect the number of lost packets, and therefore the quality of service. Analyzing the results of the experiment, the following conclusions can be drawn: the least number of lost packets occurs when the process is random or has weak trends. The fewest lost packets were at fractal dimension 1.5, i.e., when the process is completely random, there were also few lost packets at fractal dimensions close to this; persistent and anti-persistent processes (those with memory) cause more packet loss for the same traffic intensity and maximum number of packets sent from one device per unit of time. Moreover, anti-persistent processes cause significantly more losses than persistent ones. Thus, when performing traffic routing and finding optimal paths for sending IP-packets, it can be useful to determine and take into account the fractal dimension of traffic at the entrance of each router and use it when calculating metrics to determine the best routes.
Diagnosis methods for mechanisms and machines based on empirical mode decomposition of a vibrosignal and the wilcoxon test
(Національний технічний університет "Харківський політехнічний інститут", 2022) Zuev, Andrey; Ivashko, Andrey; Lunin, Denis
Methods for diagnosing mechanisms and machines based on the analysis of vibration signals are considered. In particular, the comparison of various algorithms for analyzing vibration signals in the time and frequency domains was made, methods for selecting diagnostic features and methods for secondary processing were analyzed. The purpose of the study is to develop algorithms for selecting the vibration signal envelope based on empirical mode decomposition and decomposition of the signal into intrinsic mode functions, algorithms for the spectral estimation of envelopes and to choose a criterion for making a decision on object classification. It is proposed to choose the non-parametric Wilcoxon signed-rank test to determine the statistical significance of the difference between the parameters of normal and faulty objects. The multichannel microcontroller system for collecting data from an accelerometer and transmitting it to a computer via a local Wi-Fi network, including a number of independent data gathering nodes connected to a common distributed computing system, has been developed and experimentally studied. The computer processing of the recorded vibration signals for serviceable and faulty mechanisms was performed, including data decoding, Hilbert-Huang transform, spectral analysis using the Welch and Yule-Walker methods, and the choice of a diagnostic feature that provides maximum reliability of recognition. Based on the results of the work, it was determined that the empirical mode decomposition makes it possible to obtain vibration signal envelopes suitable for further diagnostics. Recommendations are developed for choosing the intrinsic mode function and the spectral analysis algorithm, it is determined that the first intrinsic mode function is the most informative for the mechanism under study. In accordance with the Wilcoxon criterion, the degree of diagnostic reliability was numerically determined in the analysis of the spectral power density of the vibration signal and the amplitude of peaks, and the comparison of probabilities of error-free recognition for various modifications of the algorithm was made.
Excel-орієнтований калькулятор для діагностики стабільності фінансових потоків при пакетній обробці даних многочленами Чебишова
(Національний технічний університет "Харківський політехнічний інститут", 2022) Гадецька, Світлана Вікторівна; Дубницький, Валерій Юрійович; Ходирєв, Олександр Іванович; Кушнерук, Юрій Іонович; Шкодіна, Ірина Витальевна
Мета роботи. Розробка алгоритмів і програмна реалізація EXCEL-орієнтованих методів побудови регресійних многочленів з використанням многочленів Чебишова. Результати. В роботі показано, що посилення геополітичної нестабільності та вплив інших факторів тиску на стан економічних систем багатьох країн призводить до посилення вразливості їх фінансових систем. Внаслідок чого загальмувалось глобальне зростання, посилився інфляційний тиск та економічна невизначеність. Виходячи з цього, дуже важливим є діагностика змін напрямків, обсягів, швидкості, регулярності фінансових потоків суб’єктів господарювання. Прийнято, що зміна у часі показників, які визначають стан фінансової систем, може бути представлена у вигляді регресійних многочленів. У даній роботі для їх визначення було використано многочлени Чебишова. Цей метод реалізовано в програмних продуктах, використання яких пов'язане з ліцензійними обмеженнями. Тому розробка EXCEL-орієнтованого програмного продукту, призначеного для побудови регресійних рівнянь з використанням многочленів Чебишова, можна вважати актуальним завданням. В роботі наведено алгоритми обчислення коефіцієнтів регресійних многочленів Чебишова до п'ятого ступеня включно та блок-схеми алгоритмів, що їх реалізують. Також наведено визначення пакету даних, його індексу та потоку даних. Для порівняння якості многочленів Чебишова різних степенів введено поняття ланцюгового децилогу відносної похибки. В роботі прийнято, що розбіжність індексів двох суміжних потоків означає порушення стабільності процесу. Момент порушення стабільності відповідає найбільшому номеру в порівнюваній парі пакетів. Наведено блок-схему алгоритму та чисельний приклад використання методики, яку запропоновано в роботі.
Mathematical model of computer system reliability in residual classes
(Національний технічний університет "Харківський політехнічний інститут", 2022) Krasnobayev, Victor; Koshman, Serhii; Nikolsky, Serhii; Kovalchuk, Dmytro
The subject of the article is the construction of a mathematical model of the reliability of a computer system (CS) that operates in a system of residual classes (RNS). This mathematical model is based on the use of structural sliding reservation. The purpose of the article is to increase the reliability of the CS, which operates in the system of residual classes, as well as to calculate and compare the reliability, in terms of the probability of failure-free operation, of the CS in the RNS and the ternary computing system, which operates in the positional binary number system (PBNS). Tasks: to analyze the influence of the number system used on the reliability of the CS; to investigate the properties of the RNS and determine their influence on the structure of the CS in the RNS; build a mathematical model of reliability and, on its basis, perform the calculation and comparative analysis of the reliability of the CS in the RNS and the tripled CS in the PBNS. Research methods: methods of analysis and synthesis of computer systems, number theory, coding theory in RNS, reliability theory. The following results are obtained. The paper shows that the provision of a given level of reliability in the design of the CS using the RNS is due to the presence of various types of redundancy at the same time: structural, informational, temporal, functional and load. In RNS, these types of redundancy can be effectively used to improve the reliability of the CS. The CS in the RNS represents a computational structure that is identical in structure and principle of operation to the sliding structural redundancy model in the PBNS in the case of a loaded (hot) mode of operation of the redundant elements. Proceeding from this, the paper presents a mathematical model of the reliability of the CS in the RNS. In this paper, the calculation and comparative analysis of the reliability of a tripled computing structure in a PBNS with an ideal majority element and a CS in an RNS with an ideal reliability automaton are carried out. Conclusions. As shown by the results of calculations and comparative analysis in some time intervals of operation, the probability of non-failure operation of the CS in the RNS is higher than the probability of non-failure operation of the aircraft in the PBNS with a tripled majority structure. This implies the effective use of the RNS to improve the reliability of the CS.
Method of identification of tree species composition of forests on the basis of geographic information database
(Національний технічний університет "Харківський політехнічний інститут", 2022) Barabash, Oleh; Bandurka, Olena; Svynchuk, Olha; Tverdenko, Halyna
Monitoring of the forests with the help of remote sensing of the Earth systems is actual on the present stage of people development. Existing systems of research do not allow to use geographic information databases and don't include the spectrum of exploration that are presented in our work. The aim of this article is to develop the method of identification of tree species composition of forests on the basis of geographic information database in the integration with correlation analysis. It will give the possibility to find the most negative things that influence on the condition of forest ecosystems and neutralize them at the first stage of their influence. Satellite images that are received from the satellites Landsat 5 and 8 are used to make the database. Tree species composition of Mozhariv forest during 20 years is analyzed as an example in this article. Classification of tree species composition of forests using space images is made on the basis of Bayes classifier. There is a special geographic information database for further data processing and identification of tree species composition is developed. Forest is analyzed on the number of trees in each species during continuous time measures (in 2000, 2010 and 2020) in this article. Results of the work are presented with the help of graphics. Correlation analysis, which helps to make the analysis of tightness of connections between changes trees in number and different forest criteria, is made to identify tree species composition of forest. Developed method together with well-known methods of monitoring of forests help us to make effective application for analysis of tree species composition of forest changes and to make better existing information systems including different quality demands. Peculiarity of developed information system is in using of the data processing module as a part of geographic information system and implementing correlation analysis with identification of factors that influence each other. It helps to increase quality in management and monitoring of forest resources. Geographic information becomes available for users.
Methods of detection of temperature factors affecting traffic safety of railway transportation and risk analysis
(Національний технічний університет "Харківський політехнічний інститут", 2022) Bekirova, Lala; Bayramov, Aladdin
The article is dedicated to the investigation of internal and external factors affecting traffic safety of railway transport, including researching and solving ever-present issue of investigating, reducing and eliminating human factors, emergency situations and other impacts through complex methods and means. The technical state of wagons, one of the important components for traffic safety in railway transport, methods and means of detecting faults during their diagnostics, and making right decisions according to the situation are investigated. Diagnostics of the state of wagons is carried out through the method of remote measurement at measuring points installed at certain distances with a certain rule. At measuring points, the temperatures of tire boxes are investigated according to the normal limits, and risk status is assessed according to the comparison results. Accuracy and stability of diagnostics are very important for safe operation. In order to make right decisions, assessment of measurement errors of temperature factors, performing self-monitoring and correction, execution of the algorithm based on repeated measurements and points, carrying out comparison with norm limits, and making decisions provided that they are confirmed are presented. Based on Fuzzy Logic in Matlab environment, assessment of processing risks and suitable combinations are presented.
Математична модель проходження аудіосигналів у мережних системах аудіоаналітики
(Національний технічний університет "Харківський політехнічний інститут", 2022) Порошенко, Антон Ігорович
Актуальність. На сьогодні все частіше системи аудіо і відеоаналітики діють сумісно. Але у багатьох випадках необхідно оперативне передавання аудіопотоку. Тому стає актуальним завдання зменшення затримок при передачі аудіопотоків у мережних системах аудіоаналітики. Об'єкт дослідження – процес передавання аудіосигналів. Предмет дослідження – математичні моделі проходження аудіо- і відеопотоків у мережних системах. Метою даної статі є розроблення математичної моделі проходження аудіосигналів у мережних системах аудіоаналітики. Результати дослідження. Запропонована постановка задачі оптимізації мережі з'єднувальних ліній за критерієм мінімуму капітальних витрат. Складені оптимізаційні рівняння для однонаправленої трьохвузлової базової структури, виходячи із завдання мінімізації капітальних витрат. Отримані оптимізаційні рівняння для двонаправленої трьохвузлової базової структури. Проведено узагальнення отриманих оптимізаційних рівнянь на будь-яку структуру мережі з'єднувальних ліній. Напрямом подальших досліджень є розроблення наближеного методу швидкого розв'язання оптимізаційних рівнянь для мережі з'єднувальних ліній та оцінка адекватності розробленої моделі.