National Aviation University
  • Kyiv, Kyiv, Ukraine
Recent publications
The use of complex modifiers for plain cement concrete mixtures and concrete is becoming increasingly popular in modern materials science. The article presents studies of the influence of a polymer additive structured by carbon nanomaterials on physical and mechanical characteristics of plain cement concrete mixtures. IR spectroscopy and thermogravimetry have shown that the use of carbon nanomaterials significantly altered the structure of plain cement concrete mixtures. As a result of the fact that the high-strength nanomaterial is the center of crystallization of cement rock newly formed structures, a denser reinforced microstructure is formed, which significantly increases the strength properties of plain cement concrete mixtures. The inclusion of a polymer complex additive in plain cement concrete mixtures leads to higher and longer plasticizing, which plays an important role in the production of mono-lithic products. It was determined that, in the presence of a complex modifier (polymer additive structured by carbon nanotubes), the crystalline structure of calcium hydrosilicates is compacted, which causes high physical and mechanical characteristics of modified plain cement concrete mixtures. It has been experimentally shown that the additive Ethacryl HF (France) from the class of polycarboxylates, chosen for research, acts as an accelerator for setting and curing cement paste, and also increases its strength characteristics. In general, in this study, there is a water-reducing effect from the application of the additive for all plain cement concrete mixtures. Water requirements are reduced by 5 mas. %, while the strength is increased by 19%. The formulation of plain cement concrete mixtures modified by polymer additives, structured by carbon nanotubes, with high performance were developed.
UAS can be used for many applications in the frame of the concepts of Industry 4.0 and Society 5.0. But there is still a significant dependence of the UAS flights and mission realization on weather conditions. On one side the UAS operators are the user of meteorological information, on the other side, the UAS can be used for monitoring the weather conditions in addition to the primary mission. It allows to form the set of real-time data about the state of the atmosphere. The collected information can be used for early predictions and warnings of weather-related hazards and other meteorological purposes. In this context, it is important to process, extract, analyse, disseminate, and display a wide flow of information conveniently for the final user to help in his decision-making. In this paper, we are focusing on the development of software that can be used to support the decision-making of UAS operators and serve as a user-oriented platform for meteorological data representation, dissemination, and exchange.
The article describes the authors' experience creating silos for grain storage models in programs for finite element analysis of building structures. Particular attention is paid to the thin‐walled structures of the silo's vertical walls, considered an orthotropic shell of revolution. The shell is orthotropic because the silo walls are made of sinusoidal corrugated sheets and reinforced with vertical stiffeners. The direct calculation of such shells in finite element analysis programs is associated with great computational difficulties (especially in problems of geometrically nonlinear analysis). Therefore, an alternative method is proposed for creating design models of silos, which allows, without loss of analysis accuracy, to significantly reduce the dimension of models and analysis time, thereby increasing the efficiency of structural analysis. The method is helpful for the analysis silos for non‐axisymmetric loads associated with a moment stress‐strain state in the silo walls. Non‐axisymmetric actions are loads from the filling and discharge of the silos, wind effects and loads from blast waves.
The object of research is histograms of the dynamics of dangerous parameters of the gas environment, the values of which are measured in real time at the intervals of absence and ignition of materials. The method of determining histograms during a typical selection of measurements is described. This method allows one to determine histograms for samples of an arbitrary position and the size of the data interval of measurements of the dynamics of dangerous parameters of the gas environment. On the basis of histograms on the intervals of the absence and occurrence of fires of test materials, indicators of their summary statistics can be determined. Laboratory experiments were conducted to study the features of the histograms of carbon monoxide concentration, smoke density, and temperature of the gas medium for intervals of reliable absence and appearance of ignition of materials in the form of alcohol and textiles. The results of the analysis of the histograms clearly show that the dynamics of the studied dangerous parameters at the indicated intervals differ from the Gaussian. At the same time, the histograms differ in shape, which depends on the type of ignition material and the corresponding dangerous parameter. Based on the features of the histograms of the dynamics of dangerous parameters on the intervals of the absence and appearance of fires of test materials, the simplest indicators of summary statistics in the form of the range, number, and position of the modes are determined. It was established that when alcohol ignites, the variation range of carbon monoxide concentration, smoke density, and gas temperature increases from 0.545, 0.068, and 0.161 to 7.121, 0.523, and 8.71, respectively. At the same time, the range of variation of these parameters during textile ignition increases from 0.182, 0.205, and 0.323 to 0.394, 0.386, and 2.903, respectively. The obtained results in aggregate or one by one can be used in practice for early detection of fires in order to prevent the occurrence of fires in premises
The object of research is decision support systems. The subject of research is the decision-making process in management problems using the fish school (FSH) algorithm, an advanced genetic algorithm and evolving artificial neural networks. A solution search method using an improved FSH algorithm is proposed. The study is based on the FSH algorithm for finding a solution on the object state. For training FSH, evolving artificial neural networks are used. The method has the following sequence of actions: – input of initial data; – processing of initial data taking into account the degree of uncertainty; – checking the fitness function of the solution found; – procedure of feeding fish agents (FA); – instinctive-collective FA swimming; – calculation of the center of school gravity; – collective voluntary FA swimming; – changing the FA swimming parameters; – training of FA knowledge bases. The originality of the proposed method lies in the arrangement of FA taking into account the uncertainty of the initial data, improved global and local search procedures taking into account the degree of noise of data about the state of the analysis object. The peculiarity of the proposed method is the use of an improved FA training procedure. The training procedure consists in learning the synaptic weights of the artificial neural network, the type and parameters of the membership function, the architecture of individual elements and the architecture of the artificial neural network as a whole. The use of the method makes it possible to increase the efficiency of data processing at the level of 18–25 % due to the use of additional improved procedures. The proposed method should be used to solve the problems of evaluating complex and dynamic processes in the interest of solving national security problems
This paper reports data on the dynamic coefficient of friction and wear of materials of different types of friction pads and brake discs obtained from experimental research during braking under bench conditions. It was established that on the basis of the chemical composition of the materials of the friction pads with codes, in the temperature range of 100–450 °C with a step of 50 °C, the ratio of the maximum to the minimum wear of the disc varies from 6.0 to 10.0. The value of the disc wear ratio at 800 and 1000 brakings, respectively, in the temperature range of 100–250 °C and 100–450 °C was 7.6 and 14.0. This indicates that for pad materials of type A, B, C, and D under the second thermal regime, the linear wear of the working surfaces of the discs is greater than under the first thermal regime. And for the pad materials of type E and F, the wear of the discs was the same. This indicates that the use of traditional pads is characterized by a higher thermal tension of the disc brake friction pair; the absolute temperature values are in the unfavorable zone of 400–700 °C. That, in turn, could lead to both phase changes and thermal fatigue aging of materials and, as a result, to the deterioration of their tribological and thermophysical characteristics in operation. Thus, the implementation of the method of selecting pad components could improve the performance of disc brake devices of cars
The object of the study is the dynamics of air ion spread in rooms from the source of artificial air ionization under different starting conditions. There is currently the problem of distribution of air ions in the room with regulatory concentrations in all critical zones. An effective method of ensuring proper air ion concentrations is to model their propagation from ionization sources. Existing approaches to calculating the dynamics of air ions of both polarities have been improved in this study. Unlike known solutions, the impact on their concentration of electrostatic field and the interaction of air ions with suspended particles was taken into account. A model of air ion propagation in rooms with artificial air ionization and the principles of its numerical modeling was built. The use of Laplace Equation in the aerodynamic model instead of the Navier-Stokes equation for the potential of the flow rate has made it possible to design an "Ion 3D" tool, which reduces the time of implementation of one scenario from several hours to 7 seconds. Modeling of the propagation of air ions of both polarities in the room under different initial conditions was carried out. Two-dimensional and three-dimensional models with their visualization was implemented. The peculiarity of the resulting models is that they make it possible to determine the concentrations of air ions in any section of the room by three coordinates. Given this, the rapid selection of the variants of the source data makes it possible to achieve the normative values of concentrations of air ions in the area of breathing – exceeding 500 cm-3 of each polarity. Simulation makes it possible to design a room in which, under the condition of artificial ionization of air, the concentrations of air ions close to the optimal values of 3000–5000 cm-3 are provided
The object of this study is the technological operation of removing the oxide film from the surface of the metal melt, foundry production of commercial lead, zinc. To carry out the robotization of this technological operation, it is proposed to use a manipulation robot with a spherical coordinate system. A kinematic structure of a manipulation robot with six degrees of mobility and two arms is proposed. On the first arm of the manipulation robot, a movable blade is fixed, and on the second arm, a rotary blade is fixed. With the translational movement of the first hand, the movable blade rakes the oxide film onto the rotary blade. Further, the oxide film collected on the rotary blade is thrown into a special container with a rotational movement. Restrictions are introduced on the values of generalized coordinates, velocities, and accelerations for each degree of mobility of the manipulation robot. Taking into account these limitations, for the implementation of this process, software trajectories have been developed for the degrees of mobility of the manipulation robot, which are approximated by quadratic polynomials. Each program movement is divided into three sections, in the first section acceleration with a given acceleration is carried out, in the second section movement with a given speed, in the third section braking with a given acceleration. To assess the reliability of the developed software trajectories, simulations were carried out in the MatLab software environment, version R2015b. The resulting graphs of program trajectories coincide with the calculated values of the generalized coordinates, time intervals, speeds, and accelerations of change in the generalized coordinates in terms of the degrees of mobility of the manipulation robot. The period of time required to remove the oxide film is 15.88 s. On the basis of the results obtained, a cyclogram for controlling a manipulation robot was built to perform the technological operation of removing the oxide film in the production of commercial lead, zinc
The object of research is cloud computing as an element of the server infrastructure for intelligent public transport systems. Given the increasing complexity and requirements for modern transportation, the application of the Internet of Things concept has a high potential to improve efficiency and passenger comfort. Since the load generated in IoT systems is dynamic and difficult to predict, the use of traditional infrastructure with dedicated servers is suboptimal. This study considers the use of cloud computing as the main server infrastructure for the above systems. The paper investigates the main cloud platforms that can be used to develop such systems and evaluates their advantages and disadvantages. The authors developed the overall architecture of the system and evaluated the performance and scalability of individual components of the server infrastructure. To test the system, a software emulator was developed that simulates the controller module installed in vehicles. Using the developed emulator, stress tests were conducted to analyze and confirm the ability to scale and process input data by the proposed architecture. The test scenarios were developed and conducted on the basis of the existing public transportation system in Kyiv, Ukraine. The experimental results showed that the proposed IoT architecture is able to scale efficiently according to the load generated by the connected devices. It has been found that when the number of incoming messages increases from 40 to 6000, the average message processing time remains unchanged, and the error rate does not increase, which is an indicator of stable system operation. The obtained results can be used in the development of modern public transport systems, as well as for the modernization of existing ones
The object of research is the decision making support systems. The subject of the research is the decision making process in management tasks using an advanced jumping frog algorithm (JFA), an advanced genetic algorithm and evolving artificial neural networks. A method of finding solutions with the use of improved JFA is proposed. The research is based on the JFA to find a solution regarding the object state. Evolving artificial neural networks are used to train frog agents (FA). The method has the following sequence of actions: – an input of initial data; – processing of initial data taking into account the degree of uncertainty; – calculation of the value of the criterion of optimality of each permutation from the initial FA population – global search of FA; – an improvement of the FA position in the search space; – a regulation of the speed of vehicle movement. – an improvement of the working conditions of JFA; – the FA rearrangement; – an unification of all memplexes into one group; – the verification of the fulfillment of the conditions of JFA operation; – the search for the best FA; – training of the FA knowledge bases. The originality of the proposed method consists in the arrangement of the FA taking into account the uncertainty of the initial data, the improved procedures of global and local edge taking into account the degree of data noise about the analysis object state, the adjustment of the degree of data noise during the FA movement, the adjustment of the speed of the FA movement. Also, the peculiarity of the proposed method is the use of an improved procedure for FA training. The use of the method makes it possible to increase the efficiency of data processing at the level of 14–18 % due to the use of additional improved procedures. The proposed method should be used to solve the problems of evaluating complex and dynamic processes in the interests of solving national security problems
It was established that the specific weight of bank loans granted to the transport complex of Ukraine in the overall national economy is insignificant - about 3%. The largest share of bank loans in the sectoral portfolio was issued to warehousing and auxiliary activities. The second place is occupied by ground and pipeline transport, the third place is air transport. The share of water transport is negligible. The intensity of the use of loans in foreign currency is the greatest in warehousing and auxiliary activities, much less in aviation, land and pipeline transport. It was established that the share of non-performing loans in the transport complex is quite high, but smaller than in the national economy, in the national currency it is higher compared to the national economy, and in the foreign currency it is much lower. The specific weight of non-performing loans is the largest in warehousing and auxiliary activities, average - in land and pipeline transport, insignificant - in air transport, negligible - in water transport. Analysis of loans to the transport complex in terms of banking institutions made it possible to establish their exponential distribution and high concentration. TOP-3 state-owned banking institutions account for more than half of the value of loans and almost 90% of non-performing loans. TOP-14 banking institutions present almost the entire credit portfolio of the transport complex. It has been proven that one of the reasons for the high level of non-performing loans in the transport complex is the defects in assessing the creditworthiness of borrowers in the industry. Unlike other sections, a separate discriminant model was not built for section H - Transport, warehousing, postal and courier activities. The use of a single aggregated model for the transport complex and twelve other types of economic activity distorts the assessment of the borrower's creditworthiness, since the sectoral conditions of business in them differ significantly. It is proposed to build an individual model of the integral assessment of the borrower's creditworthiness according to section H with differentiation by sub-sectors.
Definitions of credit debt restructuring of banking institutions provided in several legal acts are summarized. They are reduced to changing the essential conditions of the current credit agreement to soften the requirements for the borrower in connection with his financial difficulties, the need to create favorable conditions for him to fulfill his credit obligations. The objects of restructuring under the credit agreement are: interest rate; forgiveness of part of the debt; his debt repayment schedule; terms and amounts of repayment of the main part of the loan, fees, etc. Restructuring of the bank is defined as a set of measures aimed at improving the financial condition, increasing the liquidity and solvency of the bank, carried out in the form of reorganization of the bank, change of owner, management, acceptance of debt obligations by the investor, rehabilitation, merger, division, merger, absorption at the stage, that precedes the recognition of the bank as bankrupt and the NBU's decision to liquidate it. Objects of restructuring can be: bank, enterprise, borrower's debts, tax debt, debt obligations, investment project, tax debt, debt obligations for borrowing, debt for issuing bonds. Restructuring of problematic credit debt is a type of restructuring of the borrower's debts by concluding an additional agreement with the borrower, settlement agreement, financial restructuring. The latter is the most common and is a form of economic recovery of borrowers who are in critical financial condition; changes in the conditions and repayment terms of credit obligations; ensuring borrowers' access to financing to restore their economic activity. Subjects and forms of financial restructuring are systematized. The essence of financial restructuring as an out-of-court procedure through negotiations between the borrower, his related persons and involved creditors is determined. The conditions for the borrower's participation in financial restructuring have been diagnosed, and the mechanisms for its initiation and implementation have been formalized. The responsibilities of the borrower in terms of the development and implementation of the restructuring plan are described.
The article examines the state of information security in Ukraine in the conditions of Russian military aggression. The possibilities of realizing the goals specified in Ukraine's Information Security Strategy under martial law conditions are analyzed. It is shown that Ukraine's national interests require favorable conditions for the country's political development. Thus, the interests of the individual consist in the actual provision of political rights and freedoms of citizens, society needs to strengthen democracy, and the interests of the state are expressed in the need to effectively protect the constitutional system of sovereignty and territorial integrity of the country, establish, and maintain political stability, including the strength of state power and its institutions. Based on Ukraine's national interests, strategic and current tasks of the state policy on ensuring information security are formed in the information sphere. Practical information activities have been proven to improve the state's efforts to resolve crises peacefully significantly. Conversely, ignoring informational factors and often deliberately altered information can provoke the most radical attitudes and outbursts of hostility, leading to catastrophic consequences. It is argued that the use of information technologies by the military has opened new opportunities for ensuring the state's defense. Possession of information resources and their protection in the military sphere has become the same indispensable attribute as weapons, ammunition, transport, etc. Ukraine's victory in the information conflict during the war with russia will contribute to achieving its strategic goals. It is substantiated that Ukraine's Information Security Strategy reflects the state's interests, which are expressed in the need to effectively protect the constitutional system of sovereignty and territorial integrity of the country and establish and maintain political stability, including the strength of state power and its institutions. The analysis of the implementation of the Strategy's goals showed that this process continues despite all the difficulties of martial law. Keywords: information security, Information Security Strategy of Ukraine, national interests of the state, information technologies, information struggle.
The study aims to investigate the implementation of project-based STEM activities within a blended learning framework in higher education. This approach encourages students' independent creativity and prepares them for contemporary work environments. STEM education is positioned as a tool to develop key competencies like multicultural understanding, linguistic skills, and adaptability. This innovative educational method emphasizes the real-world application of scientific, mathematical, technical, and engineering knowledge. The research methodology combines theoretical analysis with practical evaluation. Key findings underscore the significance of independent research, interdisciplinary integration, and skill development in a blended learning environment. A notable outcome emphasizes empowering students to craft scalable business models, such as startups, vital for success in today's world.
Today the prepreg technology for the manufacture of products from polymer composite materials is widely used in the global industry. This technology involves the use of prepregs obtained by preliminary impregnation of the reinforcing materials with binder solutions, which contain up to 50% environmentally sensitive and fire hazardous solvents. However, in many cases no systematic approach is used to solve the issues of choosing the optimal values of the solvent content in the binder solution to ensure its specified viscosity according, as well as the issues of safety of the industrial activity; instead, these issues are solved independently. It results in the unreasonable expense, loss of quality of the composite products and insufficient level of safety of production activity at the relevant workplaces. This study deals with the systematic prediction of the process parameters, taking into consideration the safety of operational procedures during the impregnation of prepregs and permissible range of deviations from their regulated value. The method and the relevant implementing technique for the prediction of optimal process parameters of the binder solutions for impregnation of prepregs in view of safety of the production activity have been developed. Dependences of the viscosity of the binder on its temperature and volume content of one-component, binary and three-component solvents have been obtained, with the tolerance band specified for the volume and weight contents of the solvent in the binder, which provides an acceptable deviation in the solution viscosity for the effective impregnation of prepreg. The paper proposes and substantiates the criterion of content of the binary solvent in the binder being optimal one in terms of process conditions. This criterion provides both the specified quality of impregnation of the reinforcing material and requirements for the safety of production activity. The actual hands-on examples are considered as related to the determination of optimal content of the binary solvent with the components for the specific binder and alcohol-acetone solvent. It is shown that the optimal weight concentration of acetone in the solvent is 0.085, with the solvent weight content in the mixture of 0.279. These parameters provide the maximum allowable concentration of solvent vapors, ensuring the safety of production activity. It should also be noted, that the solvent weight content differs by maximum 5% from the value required when using alcohol only, which provides high safety margin of the production activity.
The aim of the study is to analyze, systematize, and formulate scenarios for managing the integration of digital and intelligent technologies in the informatization of education based on the influence of the factors of the existing external environment. It was shown that digital transformation is a process of digital technology integration into all aspects of business activities, requiring fundamental changes in technology, culture, operations, and principles of creating new products and services. Simulation models of digital and intelligent technologies in informatization of education are proposed. Possible scenarios for the development of the education system are described: inertial and transformational. A new viable base scenario is proposed, which can be called a divergent, or school dilution scenario. It is illustrated that these three rather general scenarios show the possible place and role of digital and intellectual technologies in the changes taking place in the informatization of education today.
Introduction The Kakhovka hydropower plant on the Dnipro River in Ukraine, its spillway dam and adjoining structures were completely destroyed in the early morning of 6 June 2023 in the course of the Russia–Ukraine War. In the lower reaches of the Dnipro River, four cities and several dozen villages were extensively flooded, killing many people, and destroying or damaging industrial and urban infrastructure. Bacteriological and chemical pollution has been recorded in both the lower Dnipro River and the north-western part of the Black Sea. Water supplies have been cut off for extensive agricultural areas, several large cities and towns, and major energy stations, including the Zaporizhzhia nuclear power plant. Three major consequences of this incident are described here: those on (1) the hydraulic structure itself, (2) the territory downstream from the hydraulic structure and (3) the Kakhovske reservoir formed by the dam and nearby regions. The purpose of this study is to clarify the consequences of the destruction of the Kakhovka hydroelectric plant and dam, as well as to outline the conditions that should be expected in the near future and consider options for restoration.
The study discusses approaches to assessing the quality of sustainable development indicators and analyses sustainable development indicators in general, for which the desirability function and the approach of translating sustainable development indicators into a dimensionless scale are used. This approach makes it possible to analyse the processes of achieving the sustainable development goals and relevant tasks on the basis of statistical data, as well as to compare indicators with different characteristics. For the purpose of qualimetric assessment, the article proposes to divide the indicators of sustainable development into four groups characterized by the following parameters: the lowest value is the best, the highest value is the best, the average value is the best, and the values that simultaneously tend to the lowest and the highest. It is proposed to evaluate sustainable development indicators in accordance with the group, taking into account the significance of the indicator, for which the form parameter and the evaluation step are selected by the expert evaluation method. For example, several sustainable development indicators for different groups are presented, and calculations are made to determine the dimensionless indicator, taking into account its significance according to the opinion of experts. As a result, we obtained dimensionless values for each of the sustainable development indicators (FQ = 0.92, 0.98, 0.86, 0.28, and 0.54), which characterize the achievement of sustainable development goals and allow us to assess progress in both a prospective and retrospective context.
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1,726 members
Nikolaj Glazunov
  • Faculty of Electronics
Vladimir Ulansky
  • Department of Electronics Robotics Monitoring and IoT Technologies
Влерий Конин
  • Институт аэронавигации
Sergey Ignatovich
  • Aircraft Structure Department
E.G. Privalko
  • Department of Chemistry and Chemical Technology
Kosmonavta Komarova 1, 03058, Kyiv, Kyiv, Ukraine
Head of institution
Volodymyr Isaienko