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Документ Відкритий доступ Improving the accuracy of neural network exchange rate forecasting using evolutionary modeling method(КПІ ім. Ігоря Сікорського, 2024) Fedin, S. S.A set ofmodels of feedforward neural networks is created to obtain op-erational forecasts of the time series of the hryvnia/dollar exchange rate. It is shown that using an evolutionary algorithm for the total search of basic characteristics and a genetic algorithm for searching the values of the matrix of neural network weight coefficients allows optimizing the configuration and selecting the best neural net-work models according to various criteria of their training and testing quality. Based on the verification of forecasting results, it is established that the use of neural net-work models selected by the evolutionary modelling method increases the accuracy of forecasting the hryvnia/dollar exchange rate compared to neural network models created without the use of a genetic algorithm. The accuracy of the forecasting re-sults is confirmed by the method of inverse verification using data from different retrospective periods of the time series using the criterion of the average absolute percentage error of the forecastДокумент Відкритий доступ Strategy of the cyber-physical system for the small business enterprise guaranteed functioning with the digi-tal twin support(КПІ ім. Ігоря Сікорського, 2024) Pankratova, N. D.; Tymchik, G. S.; Pankratov, Ye. V.The article presents a strategy of the cyber-physical system guaranteed functioning for a small business enterprise (SBE), which is ensured by maintaining the digital twin and is due to its extremely high relevance in modern conditions. Business processes are linked to Industry 4.0 competencies. One of the innovations it implements is Digital Twin, a comprehensive facility support tool. Digital twin allows for tracking and effectively managing the entire cycle of an infrastructure project, from planning, procurement, and production to commissioning and maintenance of the facility. PEST, SWOT, SAW, TOPSIS, and VIKOR methods are used to build a strategy.Документ Відкритий доступ Evaluation of the thermal regime of the cathode opera-tion of a high-voltage glow discharge electron gun, which forms a ribbon electron beam(КПІ ім. Ігоря Сікорського, 2024) Melnyk, I. V.; Tuhai, S. B.; Kovalchuk, D. V.; Surzhikov, M. S.; Shved, I. S.; Skrypka, M. Yu.; Kovalenko, O. M.The article discusses the various methods of estimating the surface cathode temperature of the high-voltage glow discharge electron gun, which forms a ribbon electron beam with a linear focus. Numerical estimations have been made to design the cathode assembly of an industrial gun. It is shown that the most effective way to make approximate estimates of the temperature of the cathode surface in high-voltage glow discharge electron guns for various technological purposes is to use arithmetic-logical ratios for modeling the geometry of the cathode assembly and locus functions for estimating the temperature distribution. The accuracy of such estimates, made using the heat balance equation, was 5–10%, sufficient at the initial stage of designing an electron gun. It is shown that using the SolidWorks CAD software complex for designing high-voltage glow discharge electron guns is effective only for solving the complex engineering design tasks and preparing the corresponding technical documentation. The results of the theoretical research published in the article are of interest to a wide range of specialists engaged in developing electron beam equipment and its implementation in industrial production.Документ Відкритий доступ Study of the factor influence on the uniformity of coffee grain grinding by methods of sta-tistical analysis(КПІ ім. Ігоря Сікорського, 2024) Hryhorenko, I. V.; Kondrashov, S. I.; Hryhorenko, S. M.; Opryshkin, O. S.In order to assess the impact of each of the factors that affect the quality and uniformity of grinding coffee beans and to compare the impact of these factors, it is worth establishing a quantitative indicator of this impact. To solve this problem, dispersion analysis was used as a method of organizing sample data according to possible sources of dispersion. The chosen method made it possible to decompose the total dispersion into components caused by the influence of factor levels. Grinding time, geometric dimensions of the grain, moisture content of the grain, speed of rotation of the motor shaft were selected as factors influencing the homogeneity of grinding. The justification and assessment of the reliability of statistical conclusions about the informational significance of indicators affecting the homogeneity of coffee grinding was carried out to ensure the highest possible probability of the obtained result.Документ Відкритий доступ Identification of nonlinear systems with periodic external actions (part I)(КПІ ім. Ігоря Сікорського, 2024) Gorodetsky, ViktorThe problem of identifying nonlinear systems with periodic external ac-tions is considered in the article. The number of such actions in the system is not limited, and these actions can be either additive or multiplicative. We use a time se-ries of observed system variables to calculate unknown equation coefficients. The proven theorem allows us to separate the unknown coefficients of the system into variables and constants. The proposed computational procedure allows us to avoid possible errors caused by the discrete nature of observable time series. Identification of zero coefficients is carried out in two ways, eliminating erroneous zeroing of the terms of the equations. The method is illustrated with a numerical example of identi-fying a chaotic system with periodic external actionsДокумент Відкритий доступ Hybrid system of computational intelligence based on bagging and group method of data handling(КПІ ім. Ігоря Сікорського, 2024) Bodyanskiy, Ye.; Kuzmenko, O.; Zaichenko, He.; Zaychenko, Yu.The paper considers the problem of short- and middle-term forecasting in the financial sphere. To solve this problem, a hybrid system of computational intelligence based on the group method of data handling (GMDH) and bagging, as well as an algorithm for its training, is proposed. The odd stacks of the hybrid system are formed by ensembles of parallel connected subsystems. ARIMA and the GMDHneo-fuzzy hybrid network were chosen as such subsystems. The proposed system does not require a large training data set, automatically determines the number of stacks during training, and provides online operation. The experimental investigations were conducted using the proposed hybrid system, as well as separately using ARIMA and GMDH-neo-fuzzy. The accuracy of the predictions obtained is compared, based on which the feasibility of using the proposed hybrid system is substantiated.Документ Відкритий доступ Decentralized leader-following con-sensus control design for discrete-time multi-agent systems with switching to-pology(КПІ ім. Ігоря Сікорського, 2024) Dorofieiev, Y. I.; Lyubchyk, L. M.; Malko, M. M.The problem of consensus control of linear discrete-time multi-agent systems (MASs) with switching topology is considered in the presence of a leader. The goal of consensus control is to bring the states of all agents to the leader state while providing stability for local agents, as well as the MAS as a whole. In contrast to the traditional approach, which uses the concept of an extended dynamic multi-agent system model and communication topology graph Laplacian, this paper proposes a decomposition approach, which provides a separate design of local controllers. The control law is chosen in the form of distributed feedback with discrete PID controllers. The problem of local controllers’ design is reduced to a set of semidefinite programming problems using the method of invariant ellipsoids. Sufficient conditions for agents’ stabilization and global consensus condition fulfillment are obtained using the linear matrix inequality technique. The availability of information about a finite set of possible configurations between agents allows us to design local controllers offline at the design stage. A numerical example demonstrates the effectiveness of the proposed approach.Документ Відкритий доступ Digital medical image encryption approach in real-time applications(КПІ ім. Ігоря Сікорського, 2024) Abboud, Izz K.; Al-Rawi, Muaayed F.; Al-Awad, Nasir A.Patient information and medical imaging data are now subject to stringent data security and confidentiality standards due to the proliferation of telemedicine techniques and medical imaging instruments. Because of the problems described above, as well as the possibility of data or information being stolen, this brings up the dilemma of transmitting data on medical images via an open network. In the past, potential solutions included the utilization of methods such as information concealment and image encryption. Nevertheless, attempting to reconstruct the original image utilizing these approaches may result in complications. In the process of this paper, an algorithm for safeguarding medical images based on the pixels of interest was established. Detection of image histogram peaks for the purpose of calculating peaks in medical images pixels of interest in medical image that have had their threshold values processed. The threshold is shown by taking the average of all the peaks in the histogram. After that, a Sudoku matrix is used to assign values of interest to each of these pixels. The proposed method will be assessed by a variety of statistical procedures, and the outcomes of these analyses will be compared to previously established standards. According to the findings, the suggested method has superior security performance compared to other image encryption methods already in use.Документ Відкритий доступ Comparison of methods for interpolation and extrapolation of boundary trajectories of short-focus electron beams using root-polynomial functions(КПІ ім. Ігоря Сікорського, 2024) Melnyk, Igor V.; Pochynok, Alina V.; Skrypka, Mykhailo Yu.The article considers and discusses the comparison of interpolation and extrapolation methods of estimation of the boundary trajectory of electron beams propagated in ionized gas. All estimations have been computed using root-polynomial functions to numerically solve a differential-algebraic system of equa-tions that describe the boundary trajectory of the electron beam. By providing analy-sis, it is shown and proven that in the case of solving a self-connected interpolation-extrapolation task, the average error of the beam radius estimation is generally smaller. This approach was especially effective in estimating the focal beam radius. An algorithm for solving self-connected interpolation-extrapolation tasks is given, and its efficiency is explained. Corresponding graphic dependencies are also given and analyzedДокумент Відкритий доступ Cardiomyopathy prediction in patients with permanent ventricular pacing using machine learning methods(КПІ ім. Ігоря Сікорського, 2024) Perepeka, E. O.; Lazoryshynets, V. V.; Babenko, V. O.; Davydovych, I. V.; Nastenko, I. A.Pacing-induced cardiomyopathy is a notable issue in patients needing permanent ventricular pacing. Identifying risk groups early and swiftly preventing the ailment can reduce patient harm. However, current prognostic methods require clarity. We employed machine learning to develop predictive models using medical data. Three algorithms — decision tree, group method of data handling, and logistic regression — formed models that forecast pacing-induced cardiomyopathy. These models displayed high accuracy in predicting development, signifying soundness. Factors like age, paced QRS width, pacing mode, and ventricular index during implantation significantly influenced predictions. Machine learning can enhance pacing-induced cardiomyopathy prediction in ventricular pacing patients, aiding medical practice and preventive strategies.Документ Відкритий доступ An improved approach to organising mobile edge computing in a 5G network(КПІ ім. Ігоря Сікорського, 2024) Аstrakhantsev, А.; Globa, L.; Fedorov, О.; Degtiarov, D.; Romanko, Y.; Romanii, K.Mobile edge computing is an important element in ensuring the efficiency of the 5G network as a whole, as it enables data storage and computing at the network edge. Existing solutions do not fully address the issues of load distribution between computing nodes, and most solutions do not offer methods for verifying computations and controlling errors. Accordingly, this paper aims to develop an approach to the organization of mobile edge computing in a 5G mobile network that would authenticate distribution servers and computing nodes, manage the process of distributing computing nodes, have a procedure for verifying the correctness of calculations, and take into account the parameters of computing nodes during distribution. To achieve this goal, we propose to use the developed method. The method of load balancing and selection of computing nodes for edge computing via 5G allows for identifying available nodes and distributing computing blocks among them. It also provides mutual authentication of elements and includes a method of data verification and error detection for the MEC system. The provided solution allows for controlling errors during calculations and protecting the server from incorrect data. These methods are optimized according to minimum network resources and computing time criteria. These improvements increase the efficiency of mobile edge computing in a 5G network.Документ Відкритий доступ Generalized scenarios of transition to chaos in ideal dynamic systems(КПІ ім. Ігоря Сікорського, 2024) Horchakov, Oleksii; Shvets, AleksandrThe implementation of a new scenario of transition to chaos in the classi-cal Lorenz system has been discovered. Signs of the presence of an implementation of the generalized intermittency scenario for dynamic systems are described. Phase-parametric characteristics, Lyapunov characteristic exponents, distributions of in-variant measures, and Poincaré sections are constructed and analyzed in detail, which confirm the implementation of the generalized intermittency scenario in an ideal Lorenz systemДокумент Відкритий доступ Fairness of 2d corotational beam spline as compared with geometrically nonlinear elastic beam(КПІ ім. Ігоря Сікорського, 2024) Orynyak, Igor; Yablonskyi, Petro; Koltsov, Dmytro; Chertov, Oleg; Mazuryk, RomanThe goal of this paper is to further investigate the properties and advan-tages of corotational beam spline, CBS, as suggested recently. Emphasis is placed on the relatively simple task of drawing the spline between two endpoints with pre-scribed tangents. In the capacity of “goodness” of spline, the well-known notion of “fairness” is chosen, which presents itself as the integral from the squared curvature of spline over its length and originates from the elastic beam theory as the minimum of energy of deformation. The comparison is performed with possible variants of the cubic Bezier curve, BC, and geometrically nonlinear beam, GNB, with varying lengths. It was shown that CBS was much more effective than BC, where any at-tempt to provide better fairness of BC by varying the distances from endpoints to two intermediate points generally leads to lower fairness results than CBS. On the other hand, GNB, or in other words, the elastica curve, can give slightly better val-ues of fairness for optimal lengths of the inserted beam. It can be explained by the more sophisticated scientific background of GNB, which employs 6 degrees of free-dom in each section, compared with CBS, which operates only by 4 DoFДокумент Відкритий доступ Expansion of the mathematical apparatus of discrete-continuous networks for the automation of their synthe-sis procedures(КПІ ім. Ігоря Сікорського, 2024) Gurskiy, A. A.; Denisenko, A. V.; Goncharenko, A. E.The paper deals with a model of an intelligent system related to the automatic synthesis of Petri nets and presents a certain stage of developing this model. The peculiarity of the extended mathematical apparatus is that it contains a combination of Petri net incidence matrices to represent various algorithms. This combination of matrices is part of the equations describing the logic control device of a complex system. Accordingly, the work also presents a well-known mathematical description of discrete-continuous systems with a controlled structure, which includes certain logical control devices. This mathematical description, based on means of discrete-continuous networks, is associated with the incidence matrix of the Petri net, which is formed as a result of a particular synthesis algorithm. At the same time, the formed Petri net represents the corresponding logical control algorithm that should ensure the effective functioning of the corresponding system. The final part of the work presents various structural schemes of logic-dynamic models of systems related to the automatic synthesis of Petri nets. Here, we determine the features of the advanced mathematical apparatus based on discrete-continuous networks to develop an intelligent system that forms logical control algorithms. It is also noted that such systems can be used to create certain control algorithms that ensure increased efficiency of the functioning of some objects in difficult and unpredictable conditions.Документ Відкритий доступ Potential applications of Internet of Things: a comprehensive analysis(КПІ ім. Ігоря Сікорського, 2024) Punitha, M.; Rekha, P. M.Internet of Things (IoT) is the amalgamation of hardware, like sensors and trackers, which monitor several parameters of the environment or physical objects, and software that processes all the data gathered by hardware. Globally, the IoT market is anticipated to reach 53.8 billion USD by 2025. This enhancing demand is due to its innate ability to automate, which drives several industries to adopt IoT. In addition, minimum memory cost, processing, and storage with an increase in Big Data (BD), cloud, and conjunction of industrial networks and the internet are the added factors for the increase in IoT development. Due to this significance, IoT has applications in numerous areas like medical management, farming, wearable technology, smart energy meters, smart cities, etc. The applications are not limited to the examples mentioned above. Considering this, existing studies have considered different applications and attempted to execute them. As different applications have been focused on by these studies, the present review intends to provide a compilation of potential applications of IoT as considered by conventional research between 2018 and 2022. The study also intends to explore the advantages and disadvantages of different IoT applications (deliberated by conventional studies) through tabular analysis. Further, this review emphasizes IoT’s major key challenges and countermeasures to resolve its security issues. Finally, the study affords recommendations that will assist all IoT experts in bringing IoT products with enhanced security into the market.Документ Відкритий доступ Determination of the generalized optimality criteria for selecting civilian shelter facilities from attacks by ballistic (cruise) missiles and kamikaze drones in urbanized areas(КПІ ім. Ігоря Сікорського, 2024) Yakovenko, V.; Furmanova, N.; Flys, I.; MalyiI, O.; Farafonov, O.; Moroz, H.The object of the study is the planning of the selection of civilian shelter from attacks by ballistic (cruise) missiles and kamikaze drones in urbanized areas. A generalized model for assessing the choice of civilian shelter facilities has been developed by applying linear forms of factor linkage in combination with a general-ized optimality criterion in the form of a linear combination of local criteria. The multivariate regression analysis method was chosen to study the correlation between the generalized criterion and the observed feature. A generalized criterion for the op-timal choice of civilian shelter facilities from attacks by ballistic (cruise) missiles and kamikaze drones in urbanized areas is calculated in the form of regression coef-ficients. The criterion can facilitate a simplified determination of the generalized in-dicator of a linear model for planning the protection of civilians in cities outside the area of hostilities. The initial data is a set of physical (technical) states of shelters with a list of values and features sufficient to assess their resistance to high dynamic loadsДокумент Відкритий доступ Intelligent optimal control of nonlinear diabetic population dynamics system using a genetic algorithm(КПІ ім. Ігоря Сікорського, 2024) El Ouissari Abdellatif; El Moutaouakil KarimDiabetes is a chronic disease affecting millions of people worldwide. Several studies have been carried out to control the diabetes problem, involving both linear and non-linear models. However, the complexity of linear models makes it impossible to describe the diabetic population dynamic in depth. To capture more detail about this dynamic, non-linear terms were introduced into the mathematical models, resulting in more complicated models strongly consistent with reality (capable of re-producing observable data). The most commonly used methods for control estimation are Pantryagain’s maximum principle and Gumel’s numerical method. However, these methods lead to a costly strategy regarding material and human resources; in addition, diabetologists cannot use the formulas implemented by the proposed controls. In this paper, the authors propose a straightforward and well-performing strategy based on non-linear models and genetic algorithms (GA) that consists of three steps: 1) discretization of the considered non-linear model using classical numerical methods (trapezoidal rule and Euler–Cauchy algorithm); 2) estimation of the optimal control, in several points, based on GA with appropriate fitness function and suitable genetic operators (mutation, crossover, and selection); 3) construction of the optimal control using an interpolation model (splines). The results show that the use of the GA for non-linear models was successfully solved, resulting in a control approach that shows a significant decrease in the number of diabetes cases and diabetics with complications. Remarkably, this result is achieved using less than 70% of available resources.Документ Відкритий доступ Study on the profitability of agricultural enterprises in Ukraine during the russian military invasion of Ukraine(КПІ ім. Ігоря Сікорського, 2024) Tsesliv, O. V.; Dunaieva, T. A.; Yereshko, Ju. O.; Tsesliv, O. S.This paper examines the effectiveness of grouping agricultural enterprises according to the wheat harvested area and assesses their profitability. We have developed linear and non-linear regression equations to predict the income for said groups of enterprises. The methodology is designed for cases when future market prices are probabilistic in nature. With the help of the developed methodology, it is possible to calculate the necessary production volumes in the conditions of price fluctuations. We have used the Goldfeld–Quandt parametric test to test the model for heteroscedasticity. Calculations show that agricultural holdings are indeed inefficient, and preference should be given to enterprises with medium crop areas. Application of the Lagrange multipliers method when solving the problem of agricultural enterprise optimization makes it possible to increase profitability. The case of price risk, when future market prices are not deterministic, is considered. Therefore, it is necessary to be guided by two criteria when making managerial decisions: to maximize the expected total net income and to minimize the variance of the total net income.Документ Відкритий доступ Проекція градієнта: спрощення області мінімізації афінним перетворенням(КПІ ім. Ігоря Сікорського, 2024) Спекторський, І. Я.Розглянуто класичну задачу оптимізації у скінченновимірному просторі, тобто знаходження мінімуму функції на непорожній множині. Пошук точного розв’язку цієї задачі аналітичними методами потребує множинних обчислювальних ресурсів або взагалі неможливий. Для реальних задач частіше застосовують методи пошуку наближеного розв’язку, серед яких одним з найпростіших і найвідоміших для задач безумовної оптимізації є метод градієнтного спуску. Узагальненням методу градієнтного спуску на випадок умовної оптимізації є запропонований у 1964 р. метод проекції градієнта. Для деяких типів множини (відрізок, паралелепіпед, куля) проекцію точки на множину можна знайти простими явними формулами, проте для складніших (напр., еліпс) проектування стає окремою задачею мінімізації. Однак у деяких випадках обчислення проекції не можна спростити афінним перетворенням — напр., еліпс афінним (і навіть лінійним) перетворенням можна звести до кулі. Спрощено задачу мінімізації функції на множині застосуванням афінного перетворення F(x) = Ax+b, де A — невироджена квадратна матриця, b — фіксований вектор відповідної розмірності.Документ Відкритий доступ Statistical methods of feature engineering for the problem of forest state classification using satellite data(КПІ ім. Ігоря Сікорського, 2024) Salii, Y. V.; Lavreniuk, A. M.; Kussul, N. M.Timely detection of forest diseases is an important task for their prevention and spread limitation. The usage of satellite imagery provides capabilities for large-scale forest monitoring. Machine learning models allow to automate the analysis of these data for anomaly detection indicating diseases. However, selecting informative features is key to building an effective model. In this work, the application of Bhattacharyya distance and Spearman’s rank correlation coefficient for feature selection from satellite images was investigated. A greedy algorithm was applied to form a subset of weakly correlated features. The experiment showed that selected features allow for improving the classification quality compared to using all spectral bands. The proposed approach demonstrates effectiveness for informative and weakly correlated feature selection and can be utilized in other remote sensing tasks.