ННІ "Дніпровський металургійний інститут" (ДМетІ)

Permanent URI for this communityhttps://crust.ust.edu.ua/handle/123456789/19780

ENG: Dnipro Metallurgical Institute

Browse

Now showing 1 - 40 of 2557

08пс Steel Structure and Properties as a Result of Rolling in the Subcritical Temperature Range
(CPN Publishing Group; Scientific Publishing Center “Sci-conf.com.ua”, 2024) Kotova, Tetiana V.; Nosko, Olha A.; Aiupova, Tetiana A.
ENG: The 08пс steel structure and properties formation after rolling at subcritical temperatures with air cooling are studied. The development differs in the temperatures of the beginning and end of rolling, as well as the cooling rate in the post-deformation period. It allows to expand theoretical ideas about the patterns of 08пс deformed steel structure formation. The results of the investigation can be applied in determining rational processing modes, which involve rolling at subcritical temperatures, to increase the complex metal properties and obtain high-quality parts by cold stamping.
Accelerated Transport of Substances During Severe Plastic Deformation
(Printing House “Technologija”, Kaunas, Lithuania, 2024) Balakin, Valerii F.; Beygelzimer, Y.; Davydenko, O.; Kyryliuk, S.; Kitranov, D.; Havryliak, V.
ENG: The Severe Plastic Deformation (SPD) of the powder mixture is studied using the High Pressure Torsion method. Using the example of a mixture of aluminum, titanium and carbon powders, it is shown that SPD leads to accelerated mass transfer, which is expressed in an increase in the effective diffusion coefficient by more than 6 orders of magnitude. A hypothesis regarding the physical causes of this effect is put forward and substantiated
Active Thermoregulation in Lasius Fuliginosus Nests in Spring (Hymenoptera: Formicidae)
(Sapienza University of Rome, Rome, Italy, 2025) Stukalyuk, Stanislav; Radchenko, Yury M.; Balabukh, Vira
ENG: The aim of the study was to investigate characteristics of temperature conditions in Lasius fuliginosus nests in spring to possibly prove the spring warmup hypothesis. In spring (05.03 to 31.05.2024), 3 loggers, allowing measurements of temperature conditions were mounted on the outer walls of 3 L. fuliginosus nests in a deciduous forest near Kyiv (Ukraine). The temperature measurements were taken at 15-minute intervals. Simultaneously, the atmospheric air temperature was measured during the same period (at 3-hour intervals). Nests 1 and 2 were typical for this species: both in empty cores of oak trees (1 m diameter), while Nest 3 was auxiliary and located under a 0.05 m layer of oak bark. The physical data (air and nest wall temperatures) were used to construct a mathematical model of the thermal processes occurring in the core of a carton nest. The modelling showed that the anthills’ ability to maintain nest temperature in spring depends on their size and location inside the tree trunks exposed to environmental influence. The temperature inside a nest follows the average daily air temperature with a slight delay due to thermal inertia of the tree. The nest in tree #1 proved to be the most stable: even during cold spells as low as -5°C, the temperature in the core remained +25°C thanks to metabolic heat. Nest #2 also maintains the required temperature (+25°C) during temperature falls to +5°C. However, nest #3 does not provide conditions for offspring development during sudden cold snaps: the heat emitted is insufficient to compensate for losses at air temperatures below +20°C. This nest is not designed for active thermoregulation. It has been shown that L. fuliginosus are able to actively warm up their nest in spring, and the warmup rates (up to 25–26°C) are similar to the temperature conditions in the red forest ants’ anthills (Formica rufa group).
Adaptation of a Predicate Model in Control Problems of Nonstationary Static Objects
(Український державний університет науки і технологій, ННІ «Дніпровський металургійний інститут», ІВК ≪Системні технології≫, Дніпро, 2025) Tryputen, Mykola; Kuznetsov, Vitalii V.; Verovkin, Oleksandr; Ivliev, Vitalii
ENG: When controlling static objects at the optimization level, pattern recognition methods are used that allow partitioning the factor space into elementary subdomains in the form of n-dimensional hyperparallelepipeds. One of the main elements of the control structure for this approach to control is the adaptation algorithm, that makes it possible to refine the description of a static object under nonstationarity conditions. Repeated use of the adaptation algorithm to refine the model leads to an unjustified complication of its logical structure and the accumulation of information that has lost its relevance. The paper proposes a method for minimizing the description of images of technological situations, that makes it possible to overcome the indicated disadvantages. The method is based on the property of invariance of the number of parameters defining the hyperparallelepiped to the size of the described area in the factor space. This made it possible to identify significant boundary sub-areas in the description of the image of technological situations and, by their subsequent combination in the direction of the feature axes, to select a description with a minimum number of sub-areas. When performing these operations, “outdated” information is removed and the logical structure of a static control object is simplified as much as possible. The paper shows the possibility of implementing an algorithm for minimizing the description of images on the basis of α-algebra, that makes it possible to integrate its control structures using relational data models. The effectiveness of the proposed algorithm is confirmed by computational experiments in the control of the process of lump crushing for the conditions of a mining and processing plant.
Adaptation of a Predicate Model in Control Problems of Nonstationary Static Objects
(Український державний університет науки і технологій, ННІ ≪Дніпровський металургійний інститут≫, ІВК ≪Системні технології≫, Дніпро, 2025) Tryputen, Mykola; Kuznetsov, Vitalii V.; Yvanova Lyudmyla Kh.
ENG: When controlling static objects at the optimization level, pattern recognition methods are used that allow partitioning the factor space into elementary subdomains in the form of n-dimensional hyperparallelepipeds. One of the main elements of the control structure for this approach to control is the adaptation algorithm, that makes it possible to refine the description of a static object under nonstationarity conditions. Repeated use of the adaptation algorithm to refine the model leads to an unjustified complication of its logical structure and the accumulation of information that has lost its relevance. The paper proposes a method for minimizing the description of images of technological situations, that makes it possible to overcome the indicated disadvantages. The method is based on the property of invariance of the number of parameters defining the hyperparallelepiped to the size of the described area in the factor space. This made it possible to identify significant boundary sub-areas in the description of the image of technological situations and, by their subsequent combination in the direction of the feature axes, to select a description with a minimum number of sub-areas. When performing these operations, “outdated” information is removed and the logical structure of a static control object is simplified as much as possible. The paper shows the possibility of implementing an algorithm for minimizing the description of images on the basis of α-algebra, that makes it possible to integrate its control structures using relational data models. The effectiveness of the proposed algorithm is confirmed by computational experiments in the control of the process of lump crushing for the conditions of a mining and processing plant.
Adaptive Management of Regional Innovation Ecosystems Based on Hybrid Intelligent Support Systems
(Ukrainian State University of Science and Technologies, Dnipro, 2026) Deliiev, S. K.; Zavhorodnia, Olena O.
ENG: This study addresses the optimization of innovative development management within regional smart ecosystems. Unlike traditional management approaches, the author proposes a transition to adaptive governance based on Hybrid Decision Support Systems (HDSS). The research redefines the role of the manager in a digital environment, shifting focus from intuitive decision-making to data-driven strategic planning. By integrating Fuzzy-AHP methodology and cloud-native infrastructure, the study provides a framework for managing the lifecycle of regional innovations. The results demonstrate that hybrid intelligence effectively reduces information entropy and enhances the strategic flexibility of regional innovation systems.
Adaptive Management Strategies for Decision-Making in Business in the Context of Armed Conflict
(Elite Scientific Forum, Pakistan, 2024) Varakin, Dmytro; Osipenko, Denys; Ishchenko, Vasyl; Hlevatska, Nataliia; Hordieieva, Inna O.
ENG: Studying adaptive management strategies for businesses is crucial in modern geopolitical realities and the increasing prevalence of conflicts. Armed conflicts present challenges such as instability, security risks, supply chain disruptions, and demand shifts. These lead to uncertainty, necessitating flexibility, rapid response, and adaptation to new conditions. This research aims to develop adaptive strategies for the effective functioning and resilience of businesses in conditions of armed conflict. Research methods include reviewing scientific publications, monographic, graphical, analytical, synthesis and analysis, observation, abstraction, and generalisation. A literature review of publications by scholars from various countries on the research problem has been conducted. An analysis of the business environment in the context of military conflict, using Ukraine as a case study based on personal observations, conversations with entrepreneurs, and the processing of statistical materials, has been carried out. Comparing the Economic Sentiment Indicator before and during the war periods made it possible to identify pessimistic attitudes in business across specific sectors. The regulatory and legal acts adopted by the Ukrainian government to regulate and stimulate business activity have been characterised. Key challenges and risks affecting Ukrainian businesses in the context of military conflict have been identified. Ukraine’s main measures for restoring exports during the war have been outlined. Adaptive risk management strategies in Ukrainian businesses under military conflict conditions have been developed, with specific measures identified, along with their primary objectives.
Adjusting Properties of Electrode Pitch with Fractions of Coal Tar
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Starovoyt, Anatoly; Malyi, E.; Sorokin, E.; Starovoyt, Maria; Popova, O.
ENG: The paper presents the investigation results of the organic mass modification of the impregnating pitch of coal tar with low pyrolysis degree. The processes that form the pitch operational properties in the impregnation technology of graphitized electrodes were studied. Specific features of the modifying additive effect on the quality characteristics of the pitch and its group composition were established. Such technological approach makes it possible to intensify the impregnation process of blanks for graphitized electrodes.
Administration of Online Promotion Policy
(Publishing House “Baltija Publishing”, Riga, Latvia, 2024) Semenova, Tetіana V.; Babych, Vitalii
UKR: Управління комунікаційною політикою в Інтернеті, дослідження видів інтернет-реклами, оцінка ефективності їх використання за допомогою системи запропонованих показників. Метою статті є вдосконалення рекламної політики суб'єктів господарювання з використанням мережі Інтернет. Методологія дослідження ґрунтується на загальнонаукових методах аналізу та синтезу, індукції та дедукції, спостереження та абстрагування, які використано для систематизації здобутків теорії та практики маркетингової політики просування. Результати. Розглянуто основні методологічні підходи щодо сутності та методів розробки рекламної кампанії в Інтернеті. Проведено аналіз ефективності комунікаційної політики конкретного підприємства. Досліджено фактори зовнішнього та внутрішнього середовища фірми, що впливають на результати її діяльності. Розраховано коефіцієнт еластичності попиту на рекламу. Визначено сильні та слабкі сторони рекламної політики підприємства. Проведено аналіз показників, що характеризують товарний асортимент компанії: ширина, довжина та середня глибина товарних груп. Визначено, що компанія працює на ринку В2С та на ринку В2В. Ринок В2С включає населення і становить 95% від загального обсягу продажів компанії. Ринок В2В складається з роздрібних підприємств України: зоокомпаній та притулків для тварин. Рекламна діяльність компанії включає: виробництво кольорової друкованої рекламної продукції; виробництво сувенірної продукції; розміщення реклами в спеціалізованих друкованих виданнях; підтримку сайту; роботу з клієнтами; презентацію продукції для груп запрошених покупців; участь у галузевій виставці. Практичне значення. Найбільша частка рекламних витрат припадає на Інтернет, витрати спрямовуються на підтримку власного сайту. Просування сайту, його внутрішня і зовнішня оптимізація є найбільш ефективним інструментом маркетингових комунікацій компанії. Коефіцієнт конверсії сайту становить 6,3%, що свідчить про достатній рівень ефективності цього рекламного каналу. Цінність/оригінальність. Удосконалено систему показників, що характеризують ефективність політики просування в Інтернеті. Запропоновано та обґрунтовано рекомендації щодо вдосконалення рекламної політики компанії за рахунок використання таргетованої реклами в соціальних мережах Facebook та Instagram.
Advanced Space Vector Modulation with “Fractional” Power Cells
(Elsevier B.V., 2025) Busher, Victor; Shestaka, Anatoliy; Melnikova, Lubov; Kuznetsov, Vitaliy V.; Mykhailenko, Oleksii; Kovalenko, Viktor; Kutyk, Viktor; Osadchyi, Dmytro; Osypenko, Iryna O.; Abdel Gawad, Samer
ENG: The paper develops a model and studies various operating modes of a 5-phase multi-level cascade inverter as part of high-voltage powerful variable-frequency drives (VFD) with the most typical fan load for this type of electric drives. The aim of the work is to test the efficiency of the balanced spatial-vector pulse-width modulation method in a multi-phase high-voltage multi-level inverter in emergency modes by simulating the electric drive in the MATLAB/SIMULINK/Simscape Electrical environment. The paper studies the features of using the balanced spatial-vector pulse-width modulation method in a five-phase frequency converter in normal and emergency modes and, especially, the differences from a three-phase inverter with a similar control principle. The model with a 5-phase synchronous motor from the MATLAB ac8_example.slx database is taken as a basis, which allows us to consider the simulation results reliable. The rules for calculating phase voltages in normal and emergency modes are formulated and the corresponding blocks of the inverter control system model are prepared - a block for calculating basic vectors and a block of spatial vector pulse-width modulation (PWM). The output signals of this block are used for further processing in the modules for controlling power cells with 2- or 3-level PWM. Such a model for a 5-phase electric drive has been built for the first time, which is a scientific novelty of the work. Calculations of transient processes showed the absence of any oscillations, shocks when the system switches from normal to emergency mode and vice versa. That is, the proposed method of balanced spatial vector modulation preserves the symmetry of electromagnetic fields in the engine when individual H-bridges are damaged. It is shown that in normal mode, a 5-phase inverter using the spatial vector modulation method allows increasing the utilization factor of voltage sources by 23.1%. When individual power cells in phases fail, the utilization factor may decrease, but in any case it remains greater than 1. The method ensures compensation for emergency damage even in the event of a short circuit of one or two inverter phases. This significantly increases the service life of the electric drive, which is especially important in critical mechanisms and technological processes, where such complex inverters are actually used. The study found that when using the proposed method in a 5-phase VFD, unlike a 3-phase one, the current balance in the load is disrupted, which leads to increased heating of individual phases of both the motor and the power section of the inverter. The second point of scientific novelty of the work is that in order to reduce this negative effect, it is proposed to improve the algorithm for calculating the output coordinates of the regulator by using the so-called “fractional” power cells with a voltage that is not a multiple of their rated voltage. This leads to a smooth change in phase shifts and asymmetry when individual H-bridges and even one or two phases are damaged. This, in turn, reduces the current imbalance and the corresponding overheating from 2...3 to 12...15%, which gives confidence in the efficiency of using this improvement. It is also important to note that such a change in the control algorithm does not require any changes in the circuit and does not increase the requirements for the computing power of the processors used.
Advancement of Risk Analysis Methods during Prolonging the Service Life of Industrial Equipment
(Springer Nature Switzerland AG, 2023) Belodedenko, Sergii V.; Bilichenko, Galyna M.; Hanush, Vasyl I.; Izhevskyi, Y.
ENG: The aim of the work was to trace the relationship between the durability of the equipment and its maintenance strategy. This is done by examples of basic structures of industrial equipment. They have a long service life and during this time manage to accumulate certain damages that need to be diagnosed, after which decisions on its maintenance and repair must be made. Problems associated with the technique for extending the service life of industrial equipment are addressed. The authors have created a technique called the resource safety index (RSI), which uses this characteristic as a diagnostic metric. The usage of the risk function to control the technical state of base structures is shown in this study. It is demonstrated how the behavior of the risk function afects the choice of the inspection model. A risk function model for base structures is proposed, which is based on the concepts of stepwise assignment of the limit state and the corresponding useful life. An algorithm for determining the optimal period of restoration measures according to minimizing the cost intensity criterion, where the risk indicator is a parameter, has been developed. The proposed concepts were put into practice when deciding on the further operation of the housings of the 350 pipes rolling unit. The housings of the piercing mill and the automatic mill, which had been in operation for 80 years, were diagnosed. For the frst time, it was discovered that the housings risk function at the crack break through point stage can be represented by a linear dependence directly proportional to the accumulation of operating time. One of the signs of deterioration in the technical condition of rolling mill stands is a malfunction of the system of fxing and securing the housings.
AI Technology Implementation in Company Compliance Management
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Waszkielewicz, Wiesław; Kozenkov, Dmytro Ye.
ENG: The article examines the use of artificial intelligence (AI) in compliance as a tool for automating audits, reducing risks, and improving monitoring efficiency. It describes key AI applications, including transaction analysis (AML), risk management, automated regulatory document analysis, compliance chatbots, employee behavior monitoring, counterparty verification (KYC), audit automation, and open-source intelligence analysis. The key technologies involved in these processes are highlighted, such as machine learning, natural language processing (NLP), biometric identification, and big data analytics. The article concludes that the implementation of AI in compliance significantly enhances security, minimizes human errors, and improves adaptation to regulatory changes.
Aircraft Detection in Aerial Imagery Based on YOLO Architectures
(CEUR-WS Team, Aachen, Germany, 2025) Kashtan, Vita Yu.; Radionov, Yevhen; Hnatushenko, Volodymyr V.
ENG: The study is devoted to determining the most efficient YOLO-based architecture for the task of aircraft detection in high-resolution aerial imagery. A comparative analysis was conducted across YOLO models v8 through v11 under three experimental conditions: using pre-trained (raw) models, fine-tuning the models on a domain-specific dataset, and fine-tuning models to a dataset enhanced through a proposed image preprocessing method. The evaluation considered both accuracy and inference performance metrics. The proposed methodology reduced the false negative rate from 19.5% to 3.2% at a confidence threshold of 0.75, underscoring its effectiveness in enhancing target visibility under challenging imaging conditions such as low contrast or background clutter.
Aircraft Detection with Deep Neural Networks and Contour-Based Methods
(National University "Zaporizhzhia Polytechnic", Zaporizhzhia, 2024) Radionov, Y. D.; Kashtan, Vita Yu.; Hnatushenko, Volodymyr V.; Kazymyrenko, O. V.
ENG: Context. Aircraft detection is an essential task in the military, as fast and accurate aircraft identification allows for timely response to potential threats, effective airspace control, and national security. The use of deep neural networks improves the accuracy of aircraft recognition, which is essential for modern defense and airspace monitoring needs. Objective. The work aims to improve the accuracy of aircraft recognition in high-resolution optical satellite imagery by using deep neural networks and a method of sequential boundary traversal to detect object contours. Method. A method for improving the accuracy of aircraft detection on high-resolution satellite images is proposed. The first stage involves collecting data from the HRPlanesv2 dataset containing high-precision satellite images with aircraft annotations. The second stage consists of preprocessing the images using a sequential boundary detection method to detect object contours. In the third stage, training data is created by integrating the obtained contours with the original HRPlanesv2 images. In the fourth stage, the YOLOv8m object detection model is trained separately on the original HRPlanesv2 dataset and the dataset with the applied preprocessing, which allows the evaluation of the impact of additional processed features on the model performance. Results. Software that implements the proposed method was developed. Testing was conducted on the primary data before preprocessing and the data after its application. The results confirmed the superiority of the proposed method over classical approaches, providing higher aircraft recognition accuracy. The mAP50 index reached 0.994, and the mAP50-95 index reached 0.864, 1% and 4.8% higher than the standard approach. Conclusions. The experiments confirm the effectiveness of the proposed method of aircraft detection using deep neural networks and the process of sequential boundary traversal to detect object contours. The results indicate this approach’s high accuracy and efficiency, which allows us to recommend it for use in research related to aircraft recognition in high-resolution images. Further research could focus on improving image preprocessing methods and developing object recognition technologies in machine learning.
Alumophosphate Binders: Synthesis, Phase composition, Thermal Stability and Application in Foundry Production
(Elsevier B.V., Netherlands, 2025) Petryk, Ivan; Liutyi, Rostyslav V.; Osypenko, Irina O.; Myslyvchenko, Olexander; Byba, Ievgen; Lukianenko, Ivan
ENG: Organic binders currently used in the foundry industry are highly toxic. During the pouring of casting molds, many volatile organic compounds are released, the vast majority of which are environmentally harmful. The development of alumophosphate binders will have a positive impact on the environment. The article gives the results of the study of aluminum phosphate binders, which are the result of the chemical reaction of orthophosphoric acid with powdered aluminosilicates. The subjects of the research are the phase and chemical composition, the dynamics of thermal transformations of the binders, as well as the properties of core mixtures for the production of foundry cores. It was found experimentally that as a result of the chemical reaction of powdered pyrophyllite Al2(OH)2[Si4O10] and disten-sillimanite Al2O[SiO4] with orthophosphoric acid after heating to 300 оС, strong and thermally stable binders are formed, which are crystalline and amorphous aluminum orthophosphates. These phases ensure binding of the quartz refractory filler and therefore high strength. Synthesized binders can be used in refractories or core mixtures for foundry production. X-ray phase and differential thermogravimetric analyzes were used to determine the structure and properties of binders. The compositional planning of the experiment with appropriate data processing was applied to determine the working composition of the mixture for foundry cores. The structure of aluminum phosphate binders, which were obtained using refractory fillers common in foundry production, was investigated for the first time. The circumstances for the formation of crystalline phases were analyzed for the first time. It was established that as a result of the reaction of orthophosphoric acid and disten-sillimanite, the larger specific amount of aluminum orthophosphate and the smaller amount of residual quartz is formed, compared to the reaction of acid with pyrophyllite. This ensures the higher strength of the core mixture, which is formed from the binders in which orthophosphoric acid and disten-sillimanite are used. Taking into account the mass ratios for the whole realization of the chemical reaction of the formation of the aluminum phosphate binders, the core mixture on the basis of quartz sand, orthophosphoric acid and disten-sillimanite was developed, which hardens after heating to 300 оС and has a compressive strength of at least 2.0 MPa.
Analysis and Design of the Interval Optimal Electromechanical Systems
(ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2025) Voliansky, Roman; Kuznetsov, Vitaliy V.; Metelenko, Natalia; Kovalenko, Viktor; Spirintsev, Dmytro V.; Babyak, Mykola O.; Tryputen, Mykola; Tkalenko, Oleksandr; Halushko, Dmytro
ENG: The monograph has been prepared as part of comprehensive scientific research aimed at improving energy efficiency, digitalization, and the development of intelligent control systems. The materials presented reflect the results of many years of interdisciplinary research carried out with the participation of specialists from various scientific schools and universities. They provide a holistic understanding of modern trends in electric drive system control and form a scientific and practical basis for introducing innovative solutions in industry and transport. The discussed concepts of optimization, robust control, and the integration of renewable energy sources are closely linked to the transition to sustainable energy, automation of production processes, and infrastructure digitalization. Special attention is given to interaction with international research programs, which allows the use of advanced experience from Germany, Japan, the USA, and other countries in the field of digital twins, the industrial Internet of Things (Industrial IoT), andcyber-physical control systems.
Analysis and Research of the Causes and Course of Degradation of Lithium Batteries
(EDP Sciences-Web of conferences, 2024) Buriak, Serhii Yu.; Gololobova, Oksana O.; Havryliuk, Volodymyr I.; Serdiuk, Tetiana M.; Voznyak, Oleh M.; Manachyn, Ivan O.
ENG: Energy storage devices based on lithium technology are confidently leading the respective market due to their significant advantages over other technologies in the industry. Despite their relatively recent history of appearance, they managed to undergo many modifications of both physical and chemical components. One of the constant goals of all research in this field is the formation of knowledge about the degradation processes occurring inside a given chemical current source, and ways to influence them. Systematization and identification of the fundamental reasons for the decrease in the performance of lithium batteries still remains a topical issue of today, and therefore is considered in this article. And no matter how studied this issue looks, taking into account the existing many long-term experimental data of a huge number of scientists and a number of different types of companies, but still, optimization of work is impossible without identifying and eliminating as many destructive factors as possible in battery operation. The difficulty of this process lies also in the fact that, taking into account all the high-tech production processes in the world, there are no two identical lithium current sources. On the example of a single battery, the ability to maintain high performance, close to nominal, was demonstrated from a source that, due to its lifetime, should not have had them. The data obtained during the experiment, which confirmed the high performance, show once again that the issue of degradation of lithium current sources can and should be studied further.
Analysis of Air Dust Pollution in the Transport Compartment of the Launch Vehicle at the Stage of the Pre-launch Preparation
(Printing House “Technologija”, Kaunas, Lithuania, 2024) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Kozachyna, Valeriia V.; Mashykhina, Polina B.; Semenenko, Pavlo
ENG: At the stage of the pre-launch preparation, it is necessary to fulfill very strict environment conditions inside the main fairing where the satellite is located. Namely, it is very important to predict dust concentration inside the main fairing and especially near satellite surface during forced ventilation. To predict air dust pollution inside of main fairing 2D fluid dynamics numerical model has been developed. The governing equations include equation of potential flow to simulate air flow inside the main fairing and equation of pollutant dispersion. Also, empirical model has been used to calculate the number of dust particles fall to the satellite surface. Implicit finite difference schemes of splitting have been used for numerical integration of governing equations. The computer code has been developed on the basis of proposed numerical model. The results of computational experiments to estimate dust concentration field inside the main fairing of the launch vehicle are presented.
Analysis of CFD Modelling Results of Designed Uniflow Vortex Tube Models
(Energetická konzultačná agentura n.o., Prešov, Slovak Republic, 2025) Muzychka, Ihor; Kizek, Jan; Menkov, Andriy; Karakash, Yevhen O.; Kulikov, Andrii
ENG: This study presents the results of CFD modelling of a uniflow Vortex tube based on the Ranque-Hilsch effect. The designed models are based on experimental measurements and calculations presented in [1], with the calculations derived from relationships published by Takahama [2] and Soni [3]. The tube geometry was designed according to these relationships for an inlet pressure of 0.5 MPa, which was also used in the CFD simulations. Two different inlet air geometries were tested. The analysis focused on velocity and temperature fields in the developed mathematical models. The results will serve as a basis for the design of experimental devices.
Analysis of Changes in Global Warming Potential during Enrichment and Production of Battery-Grade Graphite Using Electrothermal Fluidized Bed Technology
(IOP Publishing Ltd, 2024) Hubynskyi, Semen M.; Sybir, Artem; Fedorov, Serhii S.; Usenko, Andrii Yu.; Hubynskyi, Mykhailo V.; Vvedenska, Tetyana
ENG: The greenhouse gas emissions during the production of anode class graphite for the conditions of Ukraine have been calculated. Conventional technologies and technologies using electrothermal fluidized bed (EFB) for natural and synthetic graphite have been studied. Calculations are carried out with respect to the whole technological chain, starting from extraction and processing of raw materials and ending with finishing processing (coating). As a result, it is shown that the technology of using EFB for purification of natural graphite and graphitization of synthetic graphite is competitive in terms of global warming potential (GWP). In the production of natural graphite using thermal purification with EFB instead of chemical purification, emissions of greenhouse gases practically remain at the same level. At the same time, the use of acids is eliminated, and the environmental impact associated with them is reduced. Production of synthetic graphite of anodic quality in EFB furnaces allows to reduce greenhouse gases (GHG) emissions by 40-50% in comparison with traditional graphitization technologies in Acheson and Kastner furnaces. The effect is achieved by reducing energy and raw material consumption.
Analysis of Methodologies for Carbon Stock Estimation in Forests
(Український державний університет науки і технологій, ННІ «Інститут промислових та бізнес технологій», ІВК «Системні технології», Дніпро, 2022) Kavats, Olena O.; Khramov, Dmitriy A.; Sergieeiva, Kateryna L.; Vasyliev, Volodymyr V.
ENG: Current approaches to carbon stock estimation in forest ecosystems are discussed. Datasets containing biomass and carbon stock estimates that can be used for training/validation in machine learning are described. Examples of applying the remote approach to assessing forest biomass over large areas are analyzed. To estimate the forest carbon stocks in Ukraine, the most promising is the remote approach, which combines ground-based and satellite measurements for forest classification and statistical modeling of carbon stocks. For training and validation of machine learning algorithms, it is proposed to use the GEDI Biomass Map covering most of the territory of Ukraine — from the southern borders to the latitude of Chernihiv in the north. A prototype of forest biomass estimating product in Ukraine can be based on publicly available MODIS NBAR data, SRTM DEM, ECMWF climate data and use the Random Forest machine learning method.
Analysis of Monolithic and Microservice Architectures Features and Metrics
(Хмельницький національний університет, Україна, 2021) Selivorstova, Tatjana V.; Klishch, Sergey M.; Kyrychenko, Serhii; Guda, Anton I.; Ostrovskaya, Kateryna Yu.
ENG: In this paper the information technologies stack is presented. These technologies are used during network architecture deployment. The analysis of technological advantages and drawbacks under investigation for monolithic and network architectures will be useful during of cyber security analysis in telecom networks. The analysis of the main numeric characteristics was carried out with the aid of Kubectl. The results of a series of numerical experiments on the evaluation of the response speed to requests and the fault tolerance are presented. The characteristics of the of monolithic and microservice-based architectures scalability are under investigation. For the time series sets, which characterize the network server load, the value of the Hurst exponent was calculated. The research main goal is the monolithic and microservice architecture main characteristics analysis, time series data from the network server accruing, and their statistical analysis. The methodology of Kubernetes clusters deploying using Minikube, Kubectl, Docker has been used. Application deploy on AWS ECS virtual machine with monolithic architecture and on the Kubernetes cluster (AWS EKS) were conducted. The investigation results gives us the confirmation, that the microservices architecture would be more fault tolerance and flexible in comparison with the monolithic architecture. Time series fractal analysis on the server equipment load showed the presence of long-term dependency, so that we can treat the traffic implementation as a self-similar process. The scientific novelty of the article lies in the application of fractal analysis to real time series: use of the kernel in user space, kernel latency, RAM usage, caching of RAM collected over 6 months with a step of 10 seconds, establishing a long-term dependence of time series data. The practical significance of the research is methodology creation of the monolithic and microservice architectures deployment and exploitation, as well as the use of time series fractal analysis for the network equipment load exploration.
Analysis of Operational Characteristics of SRM in Emergency Modes of the Converter Unit
(IEEE, 2022) Vlasenko, Vladimir; Tytiuk, Valerii; Kuznetsov, Vitalii V.; Kuntush, Yelena; Chornyi, Oleksii; Busher, Victor
ENG: The paper analyzes the issues of maintaining the operability of a switched reluctance motor (SRM) in various emergency situations. The researches were carried out using simulation modeling in the Matlab environment, the developed model was used for both normal and emergency operation modes. A series of dynamic tests of the motor torque has been carried out, and the values of the electromagnetic torque pulsation coefficient have been calculated. The possibility of maintaining the operability of SRM in the event of various emergency situations in the phases of the motor has been proved. The static mechanical characteristics of the motor are built and the calculation of the droop of the mechanical characteristics for possible emergency modes is performed. © 2022 IEEE.
Analysis of Relationships between Parameters of the National Forest Inventory of Finland: Case Study of Mesic Forest
(Geological Society Publishing House, London, UK, 2025) Kavats, Olena O.; Khramov, Dmitriy; Sergieieva, Kateryna L.
ENG: The use of satellite images and machine learning in addition to in situ data in national forest inventories enables covering large areas and significantly reduces costs. However, such combined inventories provide modelled stand properties, the relationships between which are not well understood. An approach to investigating linear and non-linear relationships between forest inventory parameters is proposed. It is applied to a study of the Multi-Source National Forest Inventory (MS-NFI) stand properties for the case of mesic forests. The relationships between MS-NFI parameters and stand reflectance in the visible, red edge, near infrared and short-wave infrared spectral regions were investigated for the Sentinel-2 satellite sensor. Linear models of canopy reflectance as a function of forest stand and elevation properties were developed. These models allowed to assess the comparative influence of MS-NFI parameters on stand reflectance as well as the monthly dynamics of this influence during the season (May–August 2019). Linear relationships between forest inventory parameters were investigated using a correlation matrix. Generalized additive models were used to investigate non-linear pairwise relationships between forest inventory parameters. The proposed approach can be applied to assess the impact of stand features obtained from conventional ground-based forest inventory on forest canopy reflectance.
Analysis of Supply and Demand in the Labor Market of Ukraine: Regional Aspect
(ACCESS Press Publishing house, 2022) Aloshyna, Tetiana; Kozenkov, Dmytro
ENG: This article is concerned with the analysis of supply and demand for labor in the regional labor market of Ukraine on the example of the Dnipropetrovsk region. The article presents the analyzes of such theoretical issues as determining the nature of the labor market, as well as supply and demand in the labor market. Particular attention is paid to the analysis of statistical data on employment and unemployment in the labor market of Dnipropetrovsk region, as well as a comparative analysis of the number of unemployed persons and the number of vacancies as the main indicators of supply and demand in the labor market of the region. Objectives: The purpose of this study is to analyze the current trends of supply and demand in the labor market of the Dnipropetrovsk region. Methods/Approach: The quantitative and qualitative methods were used to analyze statistical data posted on the website of the Office for National and Regional Statistics and Regional Employment Center. Results: The results of the investigation are presented in the form of diagrams, which clearly show the disproportion in the labor market of the region, and we can make a conclusion that the supply of labor far exceeds demand, almost twice. Conclusions: The conclusions to the study present proposals for improving the situation and establishing a balance in the labor market of the region under investigation.
Analysis of the International Competitiveness of Domestic Metallurgical Enterprises
(LLC "International Business Center", Kyiv, 2024) Faizova, Olha L.; Motiakin, Ihor V.; Hutsalova, Viktoriia I.
ENG: Introduction. The relevance of the research topic is determined by the globalization trends of economic development, the growing competitive activity of enterprises, the increase in competitive tension in world markets, the formation of specific forms of competition. The purpose of the paper is to determine and structure the factors of international competitiveness of domestic metallurgical enterprises at the mega-, macro-, meso- and micro-levels, to identify the most priority positions for winning and maintaining the market. Results. Based on the analysis of the dynamics of metal products production during 2021-2023, the current state of operation of the largest metallurgical enterprises, the dynamics of foreign investments in the metallurgical industry of Ukraine, the main reasons for the deterioration of the competitive positions of the domestic MMC on the international market of metal products are determined. The negative and positive factors that determine the international competitiveness of MMC of Ukraine at the mega-, macro-, meso- and micro-levels are analyzed. The result of the analysis is the conclusion regarding the absolute predominance of the influence of external factors in the conditions of full-scale military aggression of the Russian Federation, the significant dependence of the development of MMC of Ukraine on the state of world markets. And vice versa, domestic metallurgy has an inverse effect on the global production of metal products, because it has significant resource, production and scientific potential. Considering the specifics of metallurgical enterprises, the state of the world economy and globalization processes, the factors of competitiveness of metallurgical enterprises are structured according to the degree of susceptibility to changes in the conditions of globalization (flexible, difficult to change) and according to the degree of influence on the level of global competitiveness (moderate influence, significant impact). Conclusions. The analysis of the factors of international competitiveness of the domestic metallurgy showed that in the conditions of its sharp decline, the priority for the industry is not to lose its own competitive advantages, including through the search and effective use of positive factors of international competitiveness. At the same time, the basis of increasing the international competitiveness of the metallurgical industry is to increase the competitiveness of domestic metallurgical enterprises both on the domestic and international markets. It has been proven that when developing a strategy for increasing international competitiveness, it is appropriate to determine the result of focusing on the factors of a more intensive manifestation of the classification feature, that is, on flexible factors of significant influence.
Analysis of the Mechanism for the Occurrence of a Functional Response during Plastic Deformation of Metals and Their Alloys
(National Metallurgical Academy of Ukraine, Dnipro, 2023) Kuznetsow, E. V.
ENG: Purpose. Perfection the method for designing technological operations of metal pressure processing by establishing a functional connection between the parameters of force action and the characteristics of the natural deformation behavior of workpieces during their shape forming process. Methodology. A combined analytical approach, which is based on a synthesis of the results of fundamental and applied research in the field of physics of deformable solids, metal forming technology, as well as in related fields of natural science, is used. Findings. It is shown that the nature of the adaptive functional response of metals and their alloys to deforming influence is determined by the magnitude of possible changes in the thermodynamic potentials of the disturbed volume of the substance. From a technological point of view the most favorable response occurs when the deforming influence on the workpiece is carried out taking into account the natural ability of its substance to relaxation. Originality. The functional relationship between changes in the thermodynamic potentials of the volume of a metal or alloy and its adaptive behavior during the deformation process, as well as in the postoperative period, is described. Practical value. The findings make it possible to optimize the technological processes of machining of metals and their alloys by pressure, taking into account the natural properties and behavioral characteristics of each concrete material under concrete production conditions.
Analysis of the Neutral Grounding Modes Influence on the Reliability Characteristics of Local Systems with Renewable Energy Sources
(Polskie Towarzystwo Diagnostyki Technicznej, Warszawa, 2021) Ostapchuk, Oleksandr; Kruczek, Włodzimierz; Kuznetsov, Valeriy; Kuznetsov, Vitaliy; Tsyplenkov, Dmytro
ENG: When comparing the performance indicators of electrical networks with different types of neutral grounding, along with the fulfilment of the requirement to ensure reliability of power supply to consumers, serious attention is drawn to the main network parameters influencing the performance of power supply systems. Analysis of research and its results, reported above, on the influence of the neutral ground of power networks on the reliability and electrical safety conditions of the power supply systems as a whole, on the damage of distribution networks and electrical equipment as well as on the working capacity of relay protection devices, provides an opportunity to estimate each specific operation mode of the neutral and to develop recommendations aimed at strengthening the positive indicators of the corresponding modes. Other things being equal, reliability of power supply to electrical receivers or reliability of distribution networks is mainly determined by the damage to network elements and the performance of relay protection devices. The degree of influence of these factors on the reliability of distribution networks depends on the neutral mode, which in turn determines the level of overvoltages and the nature of transient processes at ground failure.
Analytical Method for Calculating Parameters of Destruction Diagrams of Cylindrical Rock Samples with Their Wedge Form of Destruction
(Wroclaw University of Technology, Wroclaw, Poland, 2025) Vasyliev, Leonid; Rizo, Zakhar; Vasyliev, Dmytro; Kress, Denys; Krasovskyi, Ihor; Katan, Volodymyr; Malich, Mykola H.
ENG: This study aims to develop an analytical method for calculating the parameters of destruction diagrams of cylindrical rock samples experiencing wedge-shaped fractures, facilitating the effective disintegration of rocks. The method employs analytical modeling to simulate the destruction process of cylindrical rock samples, leveraging experimental values of four key rock properties: shear resistance limit, internal friction coefficient, external friction coefficient, and elastic modulus. The proposed method accurately determines the limit and residual strength of the rock samples using these four indicators, which can be experimentally obtained through straightforward procedures in mining enterprises. This research marks the first instance of analytically modeling the destruction of cylindrical rock samples with wedge-shaped fractures while accounting for both internal and external friction. The practical application of this method allows for the rapid assessment of stress-strain parameters in rock samples, thereby enhancing the efficiency of rock disintegration processes in mining operations.
Analytical Method for Calculation of the Strength of Cylindrical Rock Specimens during Their Longitudinal Stress
(M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine, Dnipro, 2023) Vasyliev, L. M.; Vasyliev, D. L.; Malich, Mykola H.; Katan, V. A.; Rizo, Z. N.
ENG: The goal of this research is to develop a method for calculating the strength of cylindrical rock specimens under axial failure. This will allow for the management of the stress-strain state of rock masses, which is an important issue for many mining companies. To achieve this goal, analytical modeling of the process of failure of cylindrical rock specimens under axial failure was carried out. This was done using experimental values of four indicators of rock properties: shear strength, coefficients of internal and external friction, and elasticity modulus. The results of this research allow for the determination of the ultimate strength and residual strength of cylindrical rock specimens using the four property indicators. These indicators can be experimentally determined using simple methods in laboratory conditions of mining companies. The scientific novelty of this research lies in the fact that analytical modeling of the process of failure of cylindrical rock specimens under axial failure was conducted for the first time, taking into account internal and external friction. This allowed for new results to be obtained and provided a basis for the development of new methods for managing the state of rock masses. The practical significance of this research lies in the fact that the proposed method allows for the determination of the ultimate and residual strength of rock specimens using four property indicators. These indicators can be experimentally determined in mining company laboratories, making the calculation results applicable for the management of the state of rock masses and the efficient destruction of rocks during disintegration. Thus, this method has significant practical significance for the mining industry. A method for calculating the strength of cylindrical specimens under longitudinal failure mode has been developed. The average convergence of calculated strength values with fс = 0.5 to experimental data is 83.4%, which corresponds to a good level of reliability for rock materials. It has been shown that the self-organization of longitudinal failure mode in cylindrical rock specimens occurs in accordance with Coulomb's criterion of maximum effective shear stress, which has been improved to account for contact friction.
Application of Biomass Pellets for Iron Ore Sintering
(Trans Tech Publications Ltd, Switzerland, 2021) Kieush, Lina; Koveria, Andrii; Qiao Zhu, Zuo; Boyko, Maksym M.; Sova, Artem; Yefimenko, Vadym
ENG: Purpose. The use of biomass as fuel might solve several technological and environmental issues and overcome certain challenges of sinter production. In particular, as revealed by comprehensive analyses, biomass can be used as fuel for iron ore sintering. In this study, we investigate the use of some raw and pyrolysis-processed biomass pellet types, namely wood, sunflower husks (SFH), and straw, for iron ore sintering. In the experiments, the pyrolysis temperature was set to 673, 873, 1073, and 1273 K, and the proportion of biomass in the fuel composition was set to 25%. It was established that the addition of biofuels to the sintering blend leads to an increase in the gas permeability of the sintered layer. The analysis of the complex characteristics of the sintering process and the sinter strength showed the high potential of wood and sunflower husk pellets pyrolyzed at 1073 and 873 K, respectively, for iron ore sintering. The analysis of the macrostructure of the sinter samples obtained using biomaterials revealed that with higher pyrolysis temperatures; the materials tend to have greater sizes and higher amounts of pores and cracks. The composition analyses of the resultant sinters revealed that with higher temperature, the FeO content of the sinters tends to increase.
Application of Dimensional Analysis for Stable Dry Drawing Process Designing
(Інститут металофізики ім. Г. В. Курдюмова НАН України, Київ; Видавничий дім "Академперіодика", 2022) Dolzhanskiy, Anatoliy M.; Mospan, N. M.; Bondarenko, O. A.
ENG: Using the analysis of dimensions, the generalized method of designing rational modes of multiple drawing of wire with dry soapy technological lubricant is improved theoretically and experimentally, taking into account the friction mode in the drawers, other process parameters and determining the acceptable multiplicity of metal flow deformation in the mill. An algorithm is developed for calculating the rational number of rods passes through the dies during flow drawing, the use of which allows, in its implementation in practice, to ensure the stability of the technological process with the absence of wire breaks with the minimum necessary (optimal) number of metal deformation cycles and the corresponding energy consumption. The obtained results are consistent with the practice of industrial drawing with the use of dry technological lubricants on a soap base and can be used in the development of new ones and in checking the rationality of existing technological drawing processes. In the future, it is advisable to develop a program for automatic calculation according to the above algorithm for the rational number of passes during dry drawing, as well as use the presented approach to expand the initial statistical database, taking into account the properties of other steel grades that are deformed in the processes of dry and wet drawing.
Application of Neural Networks for Prediction Financial Time Series
(Scientific Publishing Center “Sci-conf.com.ua”, Perfect Publishing, 2024) Prokofiev, Taras; Ostrovska, Kateryna Yu.
ENG: The article discusses some aspects and features of the use of neural networks for forecasting financial time series for the purpose of making a profit. The use of neural networks to analyze financial information is a promising alternative (or complement) to traditional research methods. Due to their adaptability, the same neural networks can be used to analyze several instruments and markets, while the patterns found by a player for a specific instrument using technical analysis methods may work worse or not work at all for other instruments.
Application of Physical and Quantum-Chemical Characteristics of Epoxy-Containing Diluents for Wear-Resistant Epoxy Compositions
(MDPI, Basel, Switzerland, 2025) Kulikov, Andrii; Sukhyy, Kostyantyn M.; Yeromin, Oleksandr O.; Fedak, Marcel; Prokopenko, Olena M.; Sukha, Iryna V.; Poloz, Oleksii; Mikats, Oleh; Hrebik, Tomas; Kulikova, Olha; Lopusniak, Martin
ENG: Low-viscosity epoxy-containing diluents are used to reduce the initial viscosity of highly filled, wear-resistant epoxy systems and to improve filler wetting and dispersion. This study determined physical parameters by an atomic-increment approach and electronic descriptors using the Parametric Method 3 (PM3) semi-empirical method. Clear relationships were established between the effective molar cohesion energy and the solubility parameter with van der Waals volume. Linear dependencies were also obtained between the diluent surface tension and spreading coefficients on model high-hardness fillers, including silicon carbide, boron carbide, and normal corundum. The activity of epoxy diluents depends on the lowest unoccupied molecular orbital energy. These diluents influence processing and the final physical and mechanical properties of composites, making their selection critical for strength, hardness, and wear resistance. Computational analysis enables prediction of diluent behavior, reducing experimental time and cost. Integrating physical and quantum-chemical data into epoxy diluent design accelerates the search for optimal components and improves production of durable, high-performance epoxy composites.
Application of the GoldenRAM AI Platform for Monitoring Mining Activities Using Earth Observation Data
(Український державний університет науки і технологій, ІВК «Системні технології», Дніпро, 2026) Kavats, Olena O.; Sergieieva, Kateryna L.; Matselyukh, T. B.
ENG: This paper analyzes the potential of Earth remote sensing data and artificial intelligence for monitoring mining sites. The study investigates the remote assessment of the value of the deposit using multispectral imagery, time-series data, and digital elevation models. Particular attention is paid to the GoldenRAM platform, which ensures synergy between satellite data, GIS, and machine learning for automated change detection. The core innovation of this study lies in the implementation of the Artificial Intelligence Knowledge Processors (AIKP) approach, which serves as a modular foundation for a fundamental system development architecture. This methodology enables seamless integration of AI-assisted development and advanced geospatial analytics, producing a reliable framework for cross-domain monitoring. Integrating these technologies facilitates continuous remote monitoring, dynamic quarry assessment, and verification of extraction volumes. The proposed approach is highly relevant for monitoring areas with limited physical access and can be adapted for environmental analysis systems in industrial regions of Ukraine.
The Application of the Life Cycle Assessment Method in Managing the Logistics of Municipal Waste Collection
(Kasuga: Green Asia Education Center, Japan, 2023) Izdebski, Waldemar; Serafin, Sandra; Tarasevych, Viktor M.
ENG: The relevance of this topic is due to the high level of importance of sustainable waste management and the need for effective decision-making tools. The purpose of the article is to justify the possibility and expediency of using the life cycle assessment method in managing the logistics of municipal waste management. The research was conducted using general scientific methods of cognition: system analysis, synthesis, generalization, deduction, abstraction, concretization, and formalization. Given the results of the conducted research, the meaning, and essence of the evaluation method life cycle are highlighted. It was determined that the life cycle assessment method is possible and advisable to be used for analyzing the impact of waste on the environment, namely on the quality of the ecosystem, state of health of the population, and use of natural resources. It is noted that this method is an effective tool for ensuring the rational use of natural resources and effective management of waste, allowing optimizing the process of management of logistics of waste according to the criteria of time and cost. Separate attention is assigned to considering the process of adopting management solutions in the part of optimizing logistic processes in the system of managing municipal waste, which is outlined as a choice of one option from several possible ones. It is proposed that the method of life cycle assessment be applied by local authorities in Poland to substantiate management decisions regarding the choice of alternative options for processing, disposal, or dumping of municipal waste based on the criterion of minimizing the harmful impact on the environment.
Application of Two-Dimensional Padé-Type Approximations for Image Processing
(National University «Zaporizhzhia Polytechnic», Zaporizhzhia, 2023) Olevskyi, V. I.; Hnatushenko, Volodymyr V.; Korotenko, G. M.; Olevska, Yu. B.; Obydennyi, Ye. O.
ENG: Context. The Gibbs phenomenon introduces significant distortions for most popular 2D graphics standards because they use a finite sum of harmonics when image processing by expansion of the signal into a two-dimensional Fourier series is used in order to reduce the size of the graphical file. Thus, the reduction of this phenomenon is a very important problem. Objective. The aim of the current work is the application of two-dimensional Padé-type approximations with the aim of elimination of the Gibbs phenomenon in image processing and reduction of the size of the resulting image file. Method. We use the two-dimensional Padé-type approximants method which we have developed earlier to reduce the Gibbs phenomenon for the harmonic two-dimensional Fourier series. A definition of a Padé-type functional is proposed. For this purpose, we use the generalized two-dimensional Padé approximation proposed by Chisholm when the range of the frequency values on the integer grid is selected according to the Vavilov method. The proposed scheme makes it possible to determine a set of series coefficients necessary and sufficient for construction of a Padé-type approximation with a given structure of the numerator and denominator. We consider some examples of Padé approximants application to simple discontinuous template functions for both formulaic and discrete representation. Results. The study gives us an opportunity to make some conclusions about practical usage of the Padé-type approximation and about its advantages. They demonstrate effective elimination of distortions inherent to Gibbs phenomena for the Padé-type approximant. It is well seen that Padé-type approximant is significantly more visually appropriate than Fourier one. Application of the Padé-type approximation also leads to sufficient decrease of approximants’ parameter number without the loss of precision. Conclusions. The applicability of the technique and the possibility of its application to improve the accuracy of calculations are demonstrated. The study gives us an opportunity to make conclusions about the advantages of the Padé-type approximation practical usage.
Applying Machine Learning Techniques to Analyze Forest Fire Impacts on Sentinel-2 Imagery across Ukraine
(Український державний університет науки і технологій, ННІ ≪Інститут промислових та бізнес технологій≫, ІВК ≪Системні технології≫, Дніпро, 2026) Hnatushenko Viktoriia V.; Udovyk, Iryna M.; Heipke, Christian; Hnatushenko, Maksym V.
ENG: Forest fires pose severe ecological and socio-economic threats, necessitating efficient tools for rapid damage assessment. This study presents a machine learning approach for detecting burnt forest areas in Ukraine using multispectral Sentinel-2 imagery. A new manually annotated dataset was developed for training semantic segmentation models, addressing the scarcity of open data for the region. The proposed convolutional neural network, based on an encoder–decoder architecture with Xception blocks, effectively captures spectral patterns associated with fire damage. Experiments conducted on Sentinel-2 Level-2A imagery of the Kinburn Peninsula (October 2022) demonstrate high detection performance, achieving an Intersection over Union (IoU) of 95%. The results confirm the model’s capability for accurate burnt-area mapping and highlight its potential for broader applications in regional fire monitoring and environmental management.
Assessing Criteria for Casting and Deformation Suitability of Metals and Alloys
(Dnipro University of Technology, Dnipro, 2025) Kimstach, Tetiana V.; Uzlov, Kostiantyn I.; Bilyi, Oleksandr P.; Mazorchuk, Volodymyr F.; Repyakh, Serhii I.
ENG: Purpose. Based on existing criteria for predicting the suitability of metals and their alloys for manufacturing products from them by deformation or casting analysis develop a set of dimensionless parametric criteria and their quantitative scales. Their using will allow increasing the predicting accuracy of metals and alloys for their processing by pressure or casting suitability and feasibility. Methodology. The work uses phenomenological approach to systematic analysis results of metals and alloys mechanical and individual casting properties interpreting under uncertainty conditions, drawing on literature reference data, expert evaluation data and the authors’ own research results. The authors’ own data have been obtained experimentally using standard methods for mechanical properties determining and due to original authors’ method for technical purity metals and alloys based on them cast samples values of their absolutely hindered linear shrinkage determination during casting. Findings. The authors first proposed parametric dimensionless criteria and scales to them (criteria groups). Their application allows one, through such groups combinations, to assess suitability of any alloy or metal for its use possibility for products manufacturing by casting and/or pressure processing. Originality. For the first time dimensionless parametric criteria have been developed and proposed for use at initial stages of new alloys or technologies elaboration for products from them manufacturing as well as their quantitative scales for preliminary assessment (prognosis) of alloys processing feasibility by pressure or casting, regardless of their type and method. Practical value. Developed criteria and their quantitative scales using will allow alloys developers and specialized enterprises employees to save time and expenses both for alloy elaboration and for its implementation into production.
Assessment of Human-Operator’s Influence on Technical and Economic Indicators of the Excavator Production Cycle
(Dnipro University of Technology, Dnipro, 2025) Tytiuk, Valerii; Mrachkovskyi, D.; Chornyi, Oleksii; Kuznetsov, Vitalii V.; Tryputen, Mykola; Sivyakova, Galina
ENG: Purpose. Determining the influence of the parameters of the human-operator transfer function on the duration of the technological operation and the cyclic energy consumption of the electromechanical system of a straight shovel excavator equipped with electric drives of various types in order to further improve the human-machine control system of open-pit excavators by compensating for the inertia and nonlinearity of the human-operator characteristics. Methodology. Mathematical modeling of the human-machine control system of an excavator equipped with electric drives of various types, taking into account the dynamic characteristics of the human-operator, establishing regression dependencies of technical and economic indicators of the excavator on the parameters of the equivalent transfer function of the human-operator using design of experiments. Findings. The mathematical models of closed-loop control systems for the position of the bucket of a “straight shovel” excavator with an electric drive according to the Leonard system and a thyristor converter-motor electric drive have been implemented, which differ in that their structure takes into account the nonlinearity and inertia of the human operator and its influence on the performance of the human-machine system. Using the methods of the theory of experiment planning, we obtained regression dependences of the duration of the technological cycle and cycle energy consumption on the values of the time constant and the delay constant, which characterize the current state of the human-operator. The obtained regression models made it possible to evaluate the importance of the influence of various psycho-physiological factors of the human-operator on the technical and economic indicators of the excavator production cycle, which can serve as the basis for further optimization of the operation of mining excavators. Originality. For the first time, mathematical models of the electromechanical system of an excavator according to the “straight shovel” scheme are proposed, including models of electric drives of the main mechanisms, a model of the mechanical part of the excavator and a model of a human-operator, which made it possible to increase the accuracy of determining the energy consumption of the excavator and the time of the operating cycle. The regression models of technical and economic indicators of the excavator production cycle on the delay and inertia of the human-operator were obtained. It was found that the more influential factor is the transportation delay. Practical value. Mathematical models of an excavator with an electric drive based on the generator-motor system and an electric drive based on the thyristor converter-motor-motor system have been developed, including a model of the mechanical part of the excavator and a model of a human-operator. Regression models of the dependence of the duration of the excavator production cycle and its energy consumption on the delay and inertia of the human-operator are obtained. The proposed implementation of the human-machine excavator control system creates prerequisites for further increasing the level of automation of mining excavators.