Факультет Комп'ютерних технологій і систем (ФКТС ДІІТ)

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ENG: Faculty of Computer Technologies and Systems

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Abnormal Effect of Changing the Wetting Angle in Non-Equilibrium Melt–Solid Metal Systems
(G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine, Kyiv, 2024) Shtapenko, Eduard Ph.; Syrovatko, Yuliya V.
ENG: The paper deals with the temperature dependence of the contact angle of wetting of a steel substrate with a liquid tin. The experiment shows that the wetting angle is decreased as the temperature rose, and the wettability of this system is improved. However, with the further increase in temperature, the contact angle is increased again that is an abnormal phenomenon. To explain this phenomenon and the process of contact-angle formation in general, we propose the quantum mechanical model based on the Wentzel-Kramers-Brillouin (WKB) conception. In this case, interaction of the melt ions with the substrate atoms is considered indirectly through the formation of a potential barrier with the linear dimensions determined by both the ratio of masses of the atoms of interacting metals and the temperature. From the WKB standpoint, at low temperatures, when the kinetic energy of a generalized particle with the reduced mass is less than the potential barrier, the wave function decays rapidly and, accordingly, the contact angle does not actually change. Quantitative and qualitative changes appear, when the kinetic energy of particles with the reduced mass exceeds the positive barrier values because of increase in temperature. Following the WKB conception, passage or reflection of a particle with the reduced mass over the barrier is determined by the integer or half-integer ratio of the de Broglie wavelength and linear dimensions of the potential barrier. Therefore, qualitative changes in the system, i.e., the wetting threshold and abnormal increase in the contact angle, are described by the processes associated with passage or reflection of a particle with the reduced mass over the barrier. Experimental and theoretical curves of dependences of both the contact angle and the work of adhesion versus temperature show similar dynamics.
About Electromagnetic Compatibility of Track Circuits with the Traction Supply System of Railway
(Institute of Electrical and Electronics Engineers, IEEE, 2018) Serdiuk, Tetiana M.; Feliziani, Mauro; Serdiuk, Kseniia
ENG: Track circuits are of fundamental importance for the safety in railway systems. Thus, they must be immune from electromagnetic interference (EMI). To this aim they must be accurately characterized. The paper deals with the determination of spectrum composition of traction current with the electric traction. A method of measuring the parameters of track circuits (time and amplitude parameters of code current, flowing in rail lines, an input impedance of a track circuit, characteristic impedance and propagation constant) is considered Automated method of measurement of parameters of track circuits and harmonics of return traction current was elaborated by the car-laboratory. The harmonics coinciding with the code frequency are inadmissible for the track circuits.
About Optimizing of Investments Volume to Improve the Basic Indicators of the Enterprise Effectiveness
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Gasanov, Zakariia M.
EN: Purpose. Profit and profitability of any, including transport enterprises are the main economic indicators of the enterprise effectiveness. These indicators reflect the results and successful performance of the enterprise. On the other hand the enterprise effectiveness in the long term, assurance of rapid development and competitiveness is largely determined by the level of investment activity and the range of investment activity. The purpose of this study is the feasibility of the method to determine optimal investments volume for improving these or others (selectable by the management) principal economic indicators of the enterprise effectiveness. Methodology. The basis of the proposed methodology for determining the optimal investments volume is the theory of optimal control, in particular, the procedure of dynamic programming since a managed development process of the enterprise is a multiple stage. This procedure, using a phased plan, allows not only simplifying the solution of optimization problems, but also solving those, which are impossible to apply the methods of mathematical analysis. Findings. The expediency of performing the calculations to determine the optimal investments volume to ensure high rates of enterprise development was proved, it is a key to the effectiveness of the enterprise in the long term and it improves its competitiveness. Originality. It is shown that using methods of the optimum control theory one can calculate the minimum volume of capital investments for the improvement of economic indicators, which determine the enterprise effectiveness. The proposed method of calculation does not depend on the specific content of economic indicators. The effectiveness of this calculation method is demonstrated on a model example. Practical value. The proposed method of calculating the minimum volume of capital investments to improve the economic effectiveness of enterprises is quite simple, but at the same time enables, on the one hand, to determine priority directions of investment activity of the enterprise. On the other hand it improves the manageability and transparency of business enterprises, increases the head's confidence in the correctness of decisions.
About Track Circuit Calculation Method Dependent on Ferromagnet Properties in Conditions of Traction Current Noise Influence
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Zhuravlov, Anton Yu.
EN: Purpose. The work is intended to investigate the electromagnetic processes in impedance bond in order to improve noise immunity of track circuits (TC) for safe railway operation. Methodology. To achieve this purpose the methods of scientific analysis, mathematical modelling, experimental study, a large-scale simulation were used. Findings. The work examined the interference affecting the normal performance of track circuits. To a large extent, part of track circuit damages account for failures in track circuit equipment. Track circuit equipment is connected directly to the track line susceptible to traction current interference, which causes changes in its electrical characteristics and electromagnetic properties. Normal operability, performance of the main operating modes of the track circuit is determined by previous calculation of its performance and compilation of regulatory tables. The classical method for determination of track circuit parameters was analysed. The classical calculation method assumes representation of individual sections of the electrical track circuit using the quadripole network with known coefficients, usually in the A-form. Determining the coefficients of linear element circuit creates no metrological or mathematical difficulties. However, in circuits containing nonlinear ferromagnets (FM), obtaining the coefficients on the entire induction change range in the cores is quite a difficult task because the classical methods of idling (I) and short circuit (SC) are not acceptable. This leads to complicated methods for determining both the module and the arguments of quadripole network coefficients. Instead of the classical method, the work proposed the method for calculating the track circuit dependent on nonlinear properties of ferromagnets. Originality. The article examines a new approach to the calculation of TC taking into account the losses in ferromagnets (FM), without determination of equivalent circuit quadripole network coefficients. When building the FM reversal model in parallel magnetic fields, the most accurate methods are the approximation ones that take into account not only the changes in values and over time, but also their derivatives. The development of computer hardware and software makes real the mathematical methods for calculating TC with significant change in ferromagnetic inductance, including the saturation areas. Herewith, it is important to search for approximating analytical expression that describes the dynamic limit hysteresis loop (HL). Practical value. The changes in the electrical parameters of the same TC were analysed using the classical and the new calculation methods, the difference made less than 10%. The work introduced some measures to increase operational noise immunity of TC.
The Accuracy of Traction Current Harmonics Parameters Determination by Windowed FFT
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2018) Havryliuk, Volodymyr I.
EN: In the work the correct choosing of the windowed FFT parameters to achieve the necessary time and frequency resolution of the traction current spectral analysis in accordance with the re- quirements of regulatory documents has been briefly overviewed and investigations of the influence of FFT parameters on the accuracy of the determination of harmonics parameters (such as effective current, frequency, duration) have been carried out.To assess the accuracy of determining the RMS current and frequency of the harmonics, a computer study was performed using a synthesized current with known harmonics parameters, the values of which were chosen in accordance with the permissible values of the parameters determined by regulatory documents and standards.For the spectral analysis of traction current, four types of windows were selected: rectangular, Hann, Hamming and Blackman windows with duration of 0.3 and 1 s. For a sampling frequency of 27500 Hz and a window length of 0.3 s, the frequency resolution is 0.27 Hz for a rectangular window, 0.54 Hz for Hann and Hamming windows and 0.81 Hz for Blackman's window, which is consistent with the requirements of the specifications.The results of spectral analysis of traction current showed that the frequency resolution of harmonics, and accordingly the relative error in determine the frequency and the RMS value of harmonics is lower for high frequencies in spectrum.The type of windows used has a slight effect on the accuracy of determining the frequency of harmonics. The relative error of the effective value of the harmonic current was higher for a rectangular window, and relative error decreased in the row from the rectangular window to the Blackman window. The values of the relative error of the RMS current for several frequencies ofthe harmonics did not meet the requirements necessary for the practical use of the method, and this is due to spectrum leakage and scalloping.For windows with a length of 1 s, the frequency resolution of the traction current was higher. than for windows with a length of 0.3 s, and the relative error of the RMS current and frequen- cies of the harmonics were much lower, but even in this case, the relative error was high for individual frequencies .To ensure the necessary accuracy of the traction current spectral analysis with using win- dowed FFT, proper choosing of the spectral analysis parameters taking into account the traction current parameters is necessary. Taking into account a wide frequency range of traction current, a technique with variable window length and sampling frequency for different parts of the spectrum is perspective for using.
Advanced Study on Resource-Saving Methods of Forming Information Infrastructure of Sorting Stations
(BP International, West Bengal, India, 2021) Kosolapov, Anatolii A.
EN: This chapter discusses a resource-saving method for choosing a rational structure of an automated control system when technical structure migration from a centralized system based on a powerful processor to a functionally distributed system based on microcontrollers. The method allows you to determine a rational number of subsystems that effectively use the computing and financial resources of the project. The approach is illustrated by a real example of designing an automated control system for a marshalling yard.
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 Operation of Railway Communication Systems
(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2019) Botnarevscaia, R.; Serdiuk, Tetiana M.
ENG: Actuality. Technological progress, which has rapidly burst into our lives, dictates its own rules. There is a need to modernize the railway infrastructure, which, in its current equipment, built in 70-80 years of the last century, is morally and technically obsolete. Considering the huge volumes of work to be done, we come to the understanding that it is not possible to carry out such modernization in a short time, both from a financial point of view and from a technical point of view. For a long time, you will have to measure with the simultaneous operation of both new and old equipment and ensure their uninterrupted functioning. New electronic equipment introduced in various fields requires careful testing for electromagnetic compatibility. Ensuring safety in the transport of passengers and goods depends on this. So, the scientific work deals with the analysis of operation of railway communication systems are actuality. The object of research is railway communication lines. The main purpose is to evaluate the quality of different kinds of railway communication and the reasons of noise and interference in these systems. It was carried out the follows in the paper: the reasons of appearance noises in the telecommunication channels (radio and wire communications) were analyzed; the main faults in the overhead communication lines and their influence on the quality of communication were evaluated; the electromagnetic interferences in the communication lines and their frequency diapasons were researched; the further ways of investigation and simulation of influence traction and non-traction systems on the communication channels were described. The scientific novelty is in the proposition of use CST simulation to investigate electromagnetic influence of traction and non-traction power system on the communication channels with the 8-poles mathematic modelling. Research will be carried out by the method of direct measurements on existing equipment and collection of statistical data. At the end of the research, conclusions will be drawn about the electromagnetic compatibility of the of old and new equipment of communication systems, and we can say that the issue does not lose its relevance due to the introduction of new types of rolling stock, the modernization of traction substations.
Analytic Hierarchy Process Sustainability at the Significant Number of Alternatives Ranking
(CEUR-WS Team, Aachen, Germany, 2020) Shynkarenko, Viktor I.; Vasetska, Tetiana M.; Vyshnyakova, Iryna М.
ENG: This paper focuses on the need to evaluate the sustainability of Analytic hierarchy process at the Ranking of more than 10 alternatives. The proposed method is based on simulation modeling of the process of improving expert pair-wise comparison judgments. The represented method provides a stepwise improvement of the pair-wise comparison matrix transitivity. The average discrepancy and coincidence of ranks in multiple modeling are proposed as estimates of the rating stability. The application of the developed method was studied on a statistical sample formed according to the final tables of the England, Germany and Spain football championships. The method for determining probability of some alternatives ranks is developed. It is possible to modify the method for predicting the results of sports competitions and for the case of ranking with partially missing expert ratings.
Analytical Studies of the Influence of the Technological Parameters of the Process of Pulling the Strip Through the Bending-Stretching Device on the Change of the Energy-Force Parameters of the Process
(Інститут чорної металургії ім. З. І. Некрасова НАН України, м. Дніпро, 2024) Razdobrieiev, V. H.; Kluychnikov, K. Yu.; Palamar, D. H.; Leshchenko, O. I.; Ivanov, Oleksandr P.
ENG: It is impossible to imagine the modern development of technology without the use of metal products, including wire products, which are subject to high requirements in terms of variety and quality, and to the production processes, for example, wire of a fashioned profile, the flexibility of technology, high efficiency and economy, labor safety and automation. One of them is the process of drawing metal in roller dies, which combines the features of two methods of pressure metal processing - rolling and drawing. The main working tool when applying the drawing process in roller dies is a roller die with non-driven working rollers. The main drawback of the roller dies method is the presence of traction force. Stretching stresses in combination with a decrease in the plasticity of the metal during the drawing process can lead to the destruction of the rolled product. This limits the assortment of profiles, the total crimping in one of transition. It is possible to increase the plasticity of metal in two ways - thermal and mechanical. The thermal method, which is widely used in industry, requires significant energy consumption. At the same time, previous studies, which were carried out including in the ISI NASU, showed that it is possible to increase the plasticity of the metal by means of alternating sign deformation of the profiles, using, for example, equipment for straightening profiles or a scale breaker. The purpose of analytical research is to establish the dependence of the influence of the technological parameters of the drawing process in a roller drawing machine combined with the pulling of strips through a device for bending with tension (DBT) on the change of the energy parameters of the process based on the developed mathematical model. Analytical studies of the influence of the technological parameters of the DBT were carried out for the case of deformation of the initial workpiece of round cross-section with a diameter of 5.90 mm from low-carbon steel of the St.08 brand in a double-roll roller die with smooth rolls, combined with DBT in the conditions of the laboratory base of the pressure metal processing department of the Iron and Steel Institute of the Z.I. Nekrasov of NASU. On the basis of the revealed regularities, the dependences of the energy-force parameters of the process of drawing in a roller die, combined with the drawing of strip through the DBT, on the influence of the main technological parameters were obtained. It was established that an increase in the distance between of the axes rollers of the DBT at a constant value of the movement of the axis of the pressure roller of the DBT in the vertical direction leads to a decrease in the angle of coverage of the roller by the strip. It has been established that at a constant distance between the axes of the DBT rollers, when the amount of movement of the axis of the DBT pressure roller increases vertically, on the contrary, the values of the angle of coverage of the roller by the strip increase. It is shown that an increase in the number the rollers of DBR leads to an increase in both the pulling force of the strip and the normal component of the force acting on the trunnion of the rollers of the DBT. It was determined that the most significant influence of the height of the stretched strip and the radius the rollers of the DBT on the pulling force occurs in the range of relations R/h≤10. It was established that an increase in the total degree of preliminary deformation in the roller die and sign-changing deformation in the DBT of the strip leads to an increase in the value of the pulling force.
ANFIS Based Detecting of Signal Disturbances in Audio Frequency Track Circuits
(IEEE, 2020) Havryliuk, Volodymyr I.
EN: The problem considered in the work is concerned to monitoring of signal disturbances occurred in the audio frequency track circuits (AFTC). Track circuits are designed to detect the presence or absence of a train in a particular section of the rail track, and therefore, they are main and safety critical components of an automatic train control systems. Deterioration of the AFTC components appeared during their operation, as well as electromagnetic interference and adverse weather conditions can significantly change the signal current parameters, which can lead to dangerous situations for train movement. To ensure safety of railway signalling system, it is necessary to use an automatic diagnostic system that allows timely detection of appearance of significant disturbances in AFTC signal. The use for this purpose the classifiers with sharp boundaries for input diagnostic parameters and strict rules for signal classification does not allows to reveal incipient defects that arise in the ALSN system. The work investigates the effectiveness of using adaptive neuro-fuzzy inference system (ANFIS) and wavelet packet energy Shannon entropy (WPESE) for timely detecting of signal disturbances in audio frequency track circuits. The obtained results confirmed the efficiency of AFTC signal processing using ANFIS and WPESE for detecting of railway sections with unstable or faulty track circuits operation.
Application of Constructive Modeling and Process Mining Approaches to the Study of Source Code Development in Software Engineering Courses
(Split: Croatian communications and information society, Croatia, 2021) Shynkarenko, Viktor I.; Zhevaho, Oleksandr O.
ENG: We present an approach of constructing a source code history for a modern code review. Practically, it is supposed to be used in programming training, especially within initial stages. The developed constructor uses constructive-synthesizing modeling tools to classify a source code history by fine-grained changes and to construct an event log file aimed to provide information on students’ coding process. Current research applies Process Mining techniques to the software engineering domain to identify software engineering skills. By better understanding of the way students design programs, we will help novices learn programming. This research provides an innovative method of using code and development process review in teaching programming skills and is aimed to encourage using code review and monitoring coding practice in educational purposes. The standard method of evaluation takes into consideration only a final result, which doesn’t meet modern requirements of teaching programming.
Application of Fourier Transform and Wavelet Decomposition for Decoding the Continuous Automatic Locomotive Signaling Code
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Hololobova, Oksana O.; Havryliuk, Volodymyr I.
EN: Purpose. The existing system of automatic locomotive signaling (ALS) was developed at the end of the last century. This system uses the principle of a numerical code which is implemented on the basis of relay engineering, and therefore, it is exposed to various types of interferences. Over the years, the system has been upgraded several times, but the causes of faults and failures in its operation are still the subject of research. It is known that the frequency and the phase modulation of signal has a higher interference immunity as compared to the amplitude modulation. Therefore, the purpose of the article is to study the possibility of using the frequency methods such as Fourier series expansion and wavelet decomposition to extract the informational component of the received code from ALS signals under the action of various types of interferences. Methodology. One can extract the information unavailable in time representation of the signal using the signal studies in the frequency domain. The wavelet decomposition has been used for this purpose. This makes it possible to represent the local characteristics of the signal and to provide time-frequency decomposition in two spaces at the same time. Due to the high accuracy of the signal representation it is possible to analyze the time localization of spectral components and eliminate interference components even in the case of coincidence of interference frequency with the signal carrier frequency. Findings. To compare informativity of the methods of Fourier expansion and wavelet decomposition it was studied the reference and noisy signal of green fire code using the software package MATLAB. Detailed analysis of the obtained spectral characteristics showed that the wavelet decomposition provides a more correct decoding of the signal. Originality. Replacing the electromagnetic relays in the ALS system by microprocessor hardware involves the use of some mathematical tool for decoding, in order to obtain more information about the code. More often than not, as a mathematical tool, the classical Fourier decomposition is used. But because of a number of drawbacks in this method, it was suggested to use the wavelet decomposition, which has a number of advantages and accounts the disadvantages of the Fourier transform. Practical value. The presented method of code signal research can be the basis for developing dynamic model of the ALS receiver and decoder using digital processing module, which will enable to increase the reliability and accuracy of extraction of the code information component.
An Approach to Assessing the Operational Reliability of Real-Time Systems at the Stage of Conceptual Design
(ScientificWorld-NetAkhatAV, Karlsruhe, 2023) Belyaev, Nikolai; Kosolapov, Anatoliy; Egorov, Oleh Yo.; Sokur, Maria; Parpolita, Oleksandr M.
ENG: Сurrently, many facilities operate in real-time mode in an environment with a high level of radio-magneto-electronic interference. The software of such systems, debugged in stationary conditions, during the period of pilot operation gives a large number o.
Approximation of Periodic Functions of Many Variables by Functions of a Smaller Number of Variables in Orlicz Metric Spaces
(Springer, 2019) Babich, Yurii P.; Mikhailova, Tetiana F.
EN: For periodic functions of many variables, we propose a method for their approximation in the Orlicz spaces Lφ (T^m). According to this method, the functions are approximated by the sums of functions of smaller number of variables each of which is piecewise-constant in one variable for fixed values of the other variables. A Jackson-type inequality is analyzed for these approximations in terms of the mixed module of continuity.
Artificial Neural Network Based Detection of Neutral Relay Defects
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Havryliuk, Volodymyr I.
EN: Abstract. The problem considered in the work is concerned to the automatic detecting and identifying defects in a neutral relay. The special design of electromechanical neutral relays is responsible for the strong asymmetry of its output signal for all possible safety-critical influences, and therefore neutral relays have negligible values of dangerous failures rate. To ensure the safe operation of relay-based train control systems, electromechanical relays should be periodically subjected to routine maintenance, during which their main operating parameters are measured, and the relays are set up in accordance with technical regulations. These measurements are mainly done manually, so they take a lot of time (up to four hours per relay), are expensive, and the results are subjective. In recent years, fault diagnosis methods based on artificial neural networks (ANN) have received considerable attention. The ANN-based classification of relay defects using the time dependence of the transient current in the relay coil during its switching is very promising for practical utilization, but for efficient use of ANN a lot of data is required to train the artificial neural network. To reduce the ANN training time, a pre-processing of the time dependence of relay transient current was proposed using wavelet transform and wavelet energy entropy, which makes it possible to reveal the features of the main defects of the relay armature, contact springs, and magnetic system. The effectiveness of the proposed approach for automatic detecting and identifying of the neutral relays defects was confirmed during testing of the relays with various artificially created defects.
Audio Frequency Track Circuits Monitoring Based on Wavelet Transform and Artificial Neural Network Classifier
(Institute of Electrical and Electronics Engineers, IEEE, 2019) Havryliuk, Volodymyr I.
EN: Abstract. The problem of revealing and identifying of signal disturbances in audio frequency track circuits is considered in the article. Track circuits are a key component of automatic train control system and used to detect whether the rail section is free or occupied. Amplitude-modulated signals used in track circuits have low noise immunity, therefore the power wide-band-frequency interference generated by an electrified railway can cause failure operation of track circuits. To ensure the safety of the track circuits, they are subjected to periodic maintenance with registration of the signal current to the computer and measurements of its parameters. The detection of time intervals during which the interference in the track circuits exceeds certain limit values is performed by simple visual analysis of the recorded signal and is time consuming and expensive. In order to automate the revealing and identification of disturbances in audio frequency track circuits with values exceeding the certain level, a new method for processing the of the recorded signal have been proposed. At the first stage of the proposed method, the segments of a signal with interference exceeding a certain permissible level are revealed using the wavelet packet energy Shannon entropy. At the second stage, for the revealed segment with disturbances, a detailed analysis of the signal should be carried out using the digital wavelet packet transform to determine the type and parameters of the disturbances. For automatic identification of the track circuits signal disturbances, an artificial neural network classifier has been used. As a result of investigation the features of the signal disturbances in audio frequency track circuits have been extracted. The processing of the track circuits signals in accordance with the proposed method show high effectiveness in the revealing and identification of the signal disturbances.
Authorship Determination of Natural Language Texts by Several Classes of Indicators with Customizable Weights
(CEUR-WS Team, Aachen, Germany, 2021) Shynkarenko, Viktor I.; Demidovich, Inna M.
ENG: In this work we try to improve the results of texts and their fragments attribution using the classification method of the least distance in Euclidean space of images, by selecting weights for each of the image measures. For weights determination the genetic algorithm was used. Images are formed using statistical and modified recurrent analysis and the text complexity indicators. We will try to identify the effectiveness for each of them. It was found that this method usage improves the efficiency of the text attribution and the reliability of authorship determination of the texts from the control sample reaches 80-91%.
Automated Measurement of Parameters of Track Circuits
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Serdiuk, Tetiana M.
EN: The method of measuring the parameters of track circuits (a time and amplitude parameters of code current, flowing in rail lines, an input impedance of the track circuit, a characteristic impedance, a propagation constant) is considered in this paper. The algorithms of definition of parameters of track circuit (ТС) are elaborated. As a result, the develop hardware-software apparatuses allows you to define by the EMF induced in the two receiving coils separately, the following quantities: the magnitude of the code current for the entire length of the track circuit, the duration of the pulses and pauses for all parcels of code, determine the type of code signal and the type of code track transmitter, coordinate, the length of the TC, serviceability of insulating junctions and electrical connectors. The results of measurements of EMF induced in each of the receiving coils apart, the spectral composition of the noise occurring in the traction network, and harmonic amplitude and impulse noise, the causes of noise in the rail network can be revealed. Algorithm for checking the status of the track circuit involves determining the state of the track circuit and it is carried out on the current curve of the locomotive signalling depending on the coordinates obtained from the measurements. Underestimated the value of ALS current compared with the calculated value indicates an undervalued ballast resistance. The test of offered measuring apparatuses were executed on the Pridneprovsky railway.
Automated Monitoring of Content Demand in Distance Learning
(CEUR-WS Team, Aachen, Germany, 2021) Shynkarenko, Viktor I.; Raznosilin, Valentyn V.; Snihur, Yuliia
ENG: In this paper the research of means and the development of software for matching the student’s gaze focus with the structure of information on the computer monitor during distance learning is presented. Widespread hardware is envisaged to be used. Primary processing of the face image, eye regions separation is performed by means of the OpenCV library. An appropriate algorithm to calculate the center of the eye’s pupil has been developed. The influence of the system calibration process with different schemes of calibration point display, its delay time on the screen and location of the additional camera according the accuracy of the calculation the coordinates of the gaze focus is investigated. Based on the performed experiments, it was defined that the error of gaze focus recognition with using two cameras can be reduced to 4-10%. The proposed approach makes it possible for objective measurement the working time of each student with one or another part of content. The lecturer will have the opportunity to improve the content by highlighting significant parts that receive little attention and simplifying those elements that students process for an unreasonable amount of time. It is planned to integrate the developed software with the LMS Moodle in the future.
Automatic Method for Monitoring the Lower Ionosphere and Lightning Location by Tweek-Atmospherics
(Університет прикладних наук Інхолланд, Голландія, 2018) Shvets, Аleksandr V.; Krivonos, Alexey P.; Serdiuk, Tetiana M.; Hayakawa, M.
ENG: A new real-time technique is proposed for automatic identification of tweek atmospherics, distance finding to lightning and estimating the effective heights of the lower ionosphere for the fundamental and higher order modes of the Earth-ionosphere waveguide. Effectiveness of the technique is demonstrated with the experimental records of atmospherics. Application of a clustering algorithm allowed us to reveal different patterns of variations of the lower ionosphere effective height along different propagations paths. The distance finding accuracy of our tweek method had been roughly estimated by a comparison with independent data from the Blitzortung.org lightning location network to be less than 100 km with standard deviation less than 200 km in the range of distances from 500 to 1400 km.
Automation of Template Formation to Identify the Structure of Natural Language Documents
(CEUR-WS Team, Aachen, Germany, 2021) Kuropiatnyk, Olena S.; Shynkarenko, Viktor I.
ENG: In the task of text borrowings and plagiarism detection, it is important to take into account the structure of the document. This allows getting a more accurate assessment of the text and reducing the volume of material for comparison. Using a template allows identifying the structure of the document. The paper presents a constructive synthesizing model for automating the construction of a structural template of a document. Possible implementations of some algorithms by means of programming in C# are considered. Their comparative assessment is performed. Possible modification of the template is presented to increase the importance of keywords and simplify the xml-tree, which is a template.
Basis for Innovation in the Computerization of Society
(ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2022) Kosolapov, Anatolii A.; Egorov, Oleh Yo.; Dziuba, Volodymyr V.; Parpolita, Oleksandr M.
ENG: In this chapter, the authors have tried, in the context of the high rate of innovation in the computerization of society, to highlight the immutable in their view basic concepts and their definitions, which make it possible to understand the essence of the ongoing transformations. The paper considers the main stages and levels of the implementation of enterprise automation systems and components of their structures. A formula for describing the concept of "CS architecture" is proposed, a generalized structure of a WEB-system and its safe implementation is given.
Chaos in Essentially Singular 3D Dynamical Systems with Two Quadratic Nonlinearities
(Springer Science + Business Media, 2016) Belozyorov, Vasiliy Ye.
EN: A new class of 3D autonomous quadratic systems, the dynamics of which demonstrate a chaotic behavior, is found. This class is a generalization of the well-known class of Lorenz-like systems. The existence conditions of limit cycles in systems of the mentioned class are found. In addition, it is shown that, with the change of the appropriate parameters of systems of the indicated class, chaotic attractors different from the Lorenz attractor can be generated (these attractors are the result of the cascade of limit cycles bifurcations). Examples are given.
Choice of STFT and WT Parameters for Monitoring of EMI in Track Circuits
(Institute of Electrical and Electronics Engineers, 2023) Havryliuk, Volodymyr I.; Nibaruta, Regis; Radkevych, Anatolii V.
ENG: The article considers the problem of the correct choice of the parameters of the short-time Fourier transform and the continuous wavelet transform to ensure monitoring of electromagnetic interference in rails in order to ensure the electromagnetic compatibility of traction current with track circuits. The problem of correct choice of parameters for the time-frequency analysis of currents in track circuits lies in the strict requirements of the standards for the accuracy of measuring the magnitude, frequency, and duration of disturbances, as well as in the specifics of the measured current parameters and in restrictions inherent in the short-time Fourier transform and continuous wavelet transforms on the accuracy of measuring harmonic parameters. The specificity of currents in rails is associated with a large dynamic range of harmonics, a wide frequency range and the proximity of harmonics in the spectrum to each other, which makes it difficult to distinguish weak harmonics against the background of more powerful ones, as well as in the non-periodic and random nature of current. The paper considers the technology of the correct choice of parameters of the short-time Fourier transform and the continuous wavelet transforms. The results of the work were approved during testing of new types of trains.
Choice of the Optimal Parameters of Measuring the Shaft Rotation Frequency of the Hydraulic Transmission of the Locomotive Using Microcontroller
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Zhukovytskyy, Igor V.; Kliushnyk, Ihor A.
ENG: Purpose. The article provides for finding solution to the problem of developing and improving the means for measuring tachometric data of the previously created information and measuring system for testing hydraulic locomotive transmission by substantiating the optimal sensor design and signal processing algorithms. At the same time first of all it is necessary to start from the possibility of modifying the already existing test bench for hydraulic locomotive transmissions at the Dnipropetrovsk diesel locomotive repair plant «Promteplovoz». Methodology. In the work, the researchers proposed a methodology for modifying the sensor design and the algorithm for processing its signals. It is grounded on previous developments of tachometric sensor of the optical type on the basis of D-2MMU-2 sensor of the microprocessor automated test bench system of hydraulic locomotive transmission in the locomotive repair plant conditions. Selection of the necessary measurement algorithm and the number of sensor teeth is substantiated by calculating instrumental and methodological errors. Also, the studies aimed at identifying the source of interference in the measurement of rotational speed are described and solution for its elimination has been found. Findings. For the designed rotation speed sensor of the optical type based on the existing D-2MMU-2 sensor, the authors analyzed the dependence of the methodological and instrumental errors. Based on the obtained data more rational variant of the rotation speed calculation algorithm is proposed, and the number of teeth of the sensor disk is justified. Further, the main source of measurement interference was established and a method for improving the hardware of the hydraulic locomotive test bench was proposed. Originality. There were conducted the studies according to the methodological and instrumental errors of the designed rotation speed of sensor. The mechanisms of interference filtering arising from the sensor rotation speed fixing were proposed. Additional studies have shown the need for a hardware revision of signal conditioner scheme. Practical value. Conducted studies make it possible to establish a rational number of sensor disk teeth, which allows improving the measurement algorithm. It was also performed a hardware improvement of signal conditioner scheme from the sensor, helping to get rid of interferences. The results of measurements in studies are the initial data to perform further studies in order to determine the technical condition of hydraulic transmission UGP 750-1200 during factory testing after repair.
Classification of Quality Conditions of a Traction Motor Frame Insulation of Locomotives
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Kapitsa, Michail І.; Laguta, Vasiliy V.; Kozik, Yuriy
ENG: Abstract. The objective of the article is to determine the quality conditions of a locomotive traction motor frame insulation based on observations over the recovery voltage and classification of a tested insulation wear degree as well as to determine estimates of operating time until the insulation restoration or replacement with a new one. To classify the insulation quality conditions and to forecast its residual life until the restoration, a cluster analysis and discriminant analysis are used based on indicators reflecting the properties of an insulation recovery voltage curve. The study defines an information content received from frame insulation recovery voltage readings as compared with its resistance from the perspective of testing the insulation condition and predicting its residual life. Statistical characteristics of clusters corresponding to the insulation condition stages allow determining the limit values of predicting parameters and estimating the residual insulation life prior the restoration. To classify the insulation condition, an integrated evaluation of the insulation condition quality is proposed. Integrated evaluation is performed according to the recovery voltage curve and is used as an indicator during clustering. An experimental study of the proposed method practically confirmed its effectiveness.
The Comparative Analysis of Calculating Methods for Ac Impedance of R65 Type Rails and Track 1520 Mm Gauge in the Audio Frequency Range
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Havryliuk, Volodymyr I.
EN: Knowledge of the exact AC rail impedance in a wide frequency range is necessary for designing and modeling audiofrequency track circuits, determining of the traction return current distribution in rails of high-speed railways, testing new types of vehicles on electromagnetic compatibility with track circuits, etc. The aim of the work is to perform a comparative analysis of the methods for calculating of the AC impedance of the R65 type rails of a track 1520 mm gauge in the audiofrequency range. Results of AC rail impedance measurements and theoretical description of frequency dependence of impedance for wires above lossy ground are briefly reviewed. Mathematical formulation of Carson's method and the complex image method proposed by Deri with co-workers for impedance of transmission lines were represented. The impedance of running rails of R65 type and track of 1520 mm gauge have been calculated by using Carson's method and the complex image method. Due to the insufficient amount of literature data concerning AC impedance measurements for rails of type R65 of 1520 mm gauge, the results of calculations for these rails were compared with the measured values for both rails of type R65, 1520 mm gauge, as well as for rails of type UIC 60 with 1435 mm gauge. Calculated frequency dependencies of the AC impedance of R65 type rails are in good qualitative agreement with literature data for rails UIC60 in frequency range Hz... The results for rails of R65 type and 1520 mm gauge calculated according to Carson's method and complex image method differ from reference data presented in literature, and these differences increase with increasing of frequency. Such behavior may be due to error of calculation methods caused by small height of rails above lossy ground and high electrical conductivity between rails and a ground.
Comparative Analysis of Experimental and Calculation Methods for Determination of the Traction Current Harmonics Distribution in Rails
(Дніпровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Havryliuk, Volodymyr I.; Meleshko, V. V.
EN: The purpose of this work is to perform the comparative analysis of experimental and calculation methods for determination of the distribution of traction current harmonics in rails. To investigate the distribution of traction current in the rails, the special marks ("flags") were set up at a certain distance (100, 300 and 500 m) from the point of measurement along the track. The moments of passing the train past the "flags" were recorded in a computer due to a sound signal from the train, as well as visual observation. The train was moving in the measuring section in a quasistationary mode with an average speed of about 48 km/h. Traction current was measured in circuit of the interthrottle jumper with using an inductive contactless sensor and registered using computer. The distribution of the return traction current harmonics in rails for AC feeding systems were modeled by using the multiconductor transmission line (MTL) model. Some discrepancies in the results of experimental and calculation methods were observed. One of main reason of measurement errors were an inaccuracy in determining distances from the train to the measurement point. Calculation errors were related mainly with using inaccurate electrical parameters of track in model, in particular, the track ballast resistance and the ground resistances. However, in general, the considered model can be used for investigation of the traction current harmonic propagation in rails from train, and their influence on the track circuits receivers for different cases including the variation of the track circuits electrical parameters, as well as the number of rolling stock units in the feeder zone. Such analysis of harmonic in rails is important for revealing the causes of failures in railway signalling system operation under simultaneous affecting on it several factors adverse to safe operation.
The Comparative Analysis of Main Calculation Methods of Matrix Elements' Impedance of 1520 mm Rail Track Gauge in Audio Frequency Range
(Днепропетровский национальный университет железнодорожного транспорта имени академика В. Лазаряна, Днепропетровск, 2014) Havryliuk, Vladimir I.; Meleshko, V. V.
EN: With the aim of comparative analysis of main calculation methods of series impedance matrix for 1520 mm rail track gauge in audio frequency range a brief mathematical formulation revue of two methods for calculation of traction rails' impedance with consideration of earth return current has been carried out. The applicability of Carson's method and complex depth of earth return method for calculations of impedance of 1520 mm track gauge in frequency range 1005 Hz have been con-firmed. ..10 The observed differences of calculated results and measured data may be eliminated by correct choice of parameters in the calculation formulas.
Comparison of Great Britain and Ukraine Railway Systems Based on Their EMC Capability and Electrification Systems
(IEEE, 2023) Adhena, Hafte H.; Serdiuk, Tetiana M.; Thomas, David; Greedy, Steve
ENG: In this paper, a comparison based on electromagnetic compatibility capability, electromagnetic interference susceptibility, signalling, and electrification systems of Great Britain and Ukraine’s railway systems will be analyzed.
Computer architecture
(Ukrainian State University of Science and Technologies, Dnipro, 2023) Yehorov, Oleh I.; Dziuba, Volodymyr V.; Ivin, Pavlo
ENG: Methodical recommendations are intended for students of the 3rd year of the specialty 123 "Computer engineering" to prepare for practical work in the discipline "Computer architecture".
Computer Architecture
(Ukrainian State University of Science and Technologies, 2024) Kosolapov, Anatolyi; Yehorov, Oleh I. ; Tymoshenko, Liudmyla
ENG: Educational and methodical recommendations are intended for students of the 3rd year of the specialty 123 "Computer Engineering" to prepare for the coursework in the discipline "Computer Architecture". Educational and methodological recommendations contain the main theoretical provisions for mastering the material, instructions for performing coursework, requirements for analysis of results and design of works.
Computer Modeling of Air Pollution in Case of Dust Cloud Movement in Open Pit Mine
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Kirichenko, Pavlo S.; Berlov, Oleksandr V.; Gabrіnets, Volodymyr O.; Horiachkin, Vadym M.
ENG: Purpose. Explosions in open pits lead to the formation of dust clouds. These clouds lead to intense air pollution. An important task is the development of methods for predicting the dynamics of atmospheric air pollution during ex-plosions in open pits. The purpose of this work is development of a numerical model to predict atmosphere pollution after explosion in open mine pit. The task is to develop a numerical model that would allow for the calculation to take into account the geometrical shape of the open pit mine, the parameters of the meteorological situation (wind speed, atmosphere), the shape of the dust cloud that is formed in the open pit mine at the site of the explosion. Methodology. Mathematical modeling of dust cloud dispersion during an explosion in an open pit mine is based on the use of fundamental equations of aerodynamics and mass transfer. The airflow velocity field in the open pit mine is modeled using the Laplace equation for the velocity potential. The formation of the concentration field of dust is mod-eled on the basis of the equation of convective-diffusion dispersion of an impurity. For numerical integration of model-ing equations, difference schemes are used. The Laplace equation for the velocity potential is numerically integrated using the Richardson method. For the numerical integration of the convective-diffusion dispersion equation for an im-purity, an implicit difference splitting scheme is used. Findings. A CFD model has been developed that allows you to calculate the formation of pollution zones during the movement of a dust cloud in the open pit mine. A feature of the developed model is the speed of calculation. For practical use of the developed model, standard input information is required. Originality. In contrast to the existing models in Ukraine, the developed numerical model allows taking into account the geometrical shape of the open pit mine and the geometrical shape of the dust cloud when making predictive calculations to assess the level of air pollution caused by explosions in open pits. Practical value. The developed nu-merical model can be implemented on computers of low and medium power. For practical use of the numerical model, standard information on meteorological conditions in open pit mine is required. The numerical model can be used for environmental assessment of the effect of explosions in open pit mine on environmental pollution and work areas.
Concave Shells of Continuity Modules
(Springer, 2019) Pichugov, Sergey A.
EN: We prove the inequality ω¯(t)≤infs>0(ω(s2)+ω(s)st), where ω(t) is a function of the modulus-of-continuity type and ω¯(t) is its smallest concave majorant. The consequences obtained for Jackson’s inequalities in C2πare presented.
Conceptual Resource-Saving Design of Real-Time Socio-Technical Systems
(IOP Publishing Ltd, England, 2021) Kosolapov, Anatolii A.; Ivin, Pavlo
EN: The article discusses the methodological resource-saving approach to the System design of socio-technical systems for real-time managing (STS RTM). The definition of STS RTM from the point of view of computer systems architecture is introduced. This approach made it possible to classify the main paradigms of using computer systems, including the modern stage, corresponding to STS RTM. For such complex systems, it is important to ensure their energy efficiency, which is ensured by the use of resource-saving models and methods for optimizing structural solutions. This is ensured by minimizing the total length of communications at the enterprise, saving computing and financial resources during system migration from a centralized structure to a functionally distributed hierarchical multi-microcontroller system. STS is a human a real-time machine system, therefore, the system's response time to the processing of requests related to the issuance of messages to the system's operating personnel is determined. The complex of formulated tasks and their solution on a common information and analytical base is extremely difficult without a unified system design methodology and automation tools for solving problems. Such a Framework is described in this article.
Conceptualization of the Tabular Representation of Knowledge
(IEEE, 2021) Shynkarenko, Viktor I.; Zhuchyi, Larysa I.; Ivanov, Oleksandr P.
ENG: Tabular representation is used as a basis for knowledge extraction. The structure of knowledge is built from a generalized concept to data structures that are used in applied software. The resulting formalizations allow for control of information in the form of natural language texts (regulatory documents), databases and spreadsheets of automated transport systems. The knowledge extracted from the tabular representation serves as the basis for decision-making and data mining.
Consideration of the Upper Error Bound of Measurement Complex in the Analysis of Digitized Signals
(Український державний університет науки і технологій, Дніпро, 2025) Zubko, Andrii V.; Shcheka, Vadym I.
ENG: Purpose. This work aims to: enhancing the reliability of certification tests for new rolling stock by integrating measurement system error considerations into the data analysis process; ensuring a more precise evaluation of compliance with safety and performance standards, minimizing the risk of undetected defects that could emerge during operation; improving risk assessment by reducing measurement uncertainties, thereby strengthening the decision-making process for rolling stock approval. Methodology. Analyzing existing approaches to certifying new rolling stock in accounting for measurement system errors. Developing a method for systematically integrating these errors into the data analysis process to enhance result accuracy. Assessing the impact of this approach on certification reliability and its effectiveness in identifying potential operational risks before deployment. Findings. An improved certification process incorporating measurement system error considerations has been proposed. The study demonstrates that this approach significantly reduces the probability of overlooking defects that may only become apparent during operation, thereby increasing the overall reliability of certification tests. Originality. A method for assessing the reliability of certification test data while considering measurement system errors has been developed. It has been proven that integrating these data into the test analysis process improves the accuracy of predicting the operational reliability of rolling stock and enhances the overall effectiveness of certification procedures. Practical value. The proposed approach enhances railway transport safety by ensuring a more reliable and accurate certification process for new rolling stock. This is particularly relevant in the context of Ukraine’s railway fleet modernization, including the intro-duction of Hyundai Rotem and Tarpan electric trains, as well as Škoda locomotives. By refining certification procedures, this methodology contributes to safer and more efficient railway operations.
Constructive Model of the Natural Language
(Institute of Informatics, University of Szeged, Hungary, 2018) Shynkarenko, Viktor I.; Kuropiatnyk, Olena S.
ENG: The paper deals with the natural lenguage model. Elements of the model (the language constructions) are images with such attributes as sounds, let- ters, morphemes, words and other lexical and syntactic components of the language. Based on the analysis of processes of the world perception, visual and associative thinking, the operations of formation and transformation of images are pointed out. The model can be applied in the semantic NLP.
Constructive Modeling of Lightning Activity in Thunderstorm Front
(Institute of Electrical and Electronics Engineers (IEEE), 2019) Shynkarenko, Viktor I.; Lytvynenko, Kostiantyn; Chyhir, Robert; Sansiieva, Iryna
ENG: Using the tools of constructive-synthesizing modeling, constructors of fractal time series which determine the location, magnitude and rate of damping of lighting discharges are developed. Model video images of lightning in the thunderstorm front are formed according to constructors' implementation. The adequacy of the model is verified by comparison of the model video image with the same produced by NASA satellite.