Browsing by Author "Rybalka, Roman V."

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Determining the Set of Elements for Automatic Monitoring and Diagnosing the Relay Interlocking System
(Kaunas University of Technology, Kaunas, Lithuania, 2022) Malovichko, Volodymyr V.; Rybalka, Roman V.; Malovichko, Natalia V.; Honcharov, Kostiantyn V.
ENG: The majority of train movement control within a station in Ukraine railways is achieved by the relay interlocking system (RI). There is no self-diagnosing in RI systems. Therefore, the time spent on failure recognition, localization and correction (especially those that occurred in the RI tower) is significant. Most RIs have been operating for more than 30 years, yielding a gradual increase in the failure rate and, consequently, delays. Failure effects can be reduced by automating the process of failure localization in RI applying the appropriate automatic monitoring and diagnosing (AMD) system. A subset of input signals of the latter is composed of signals from the sensors that measure the states of RI's elements. A large number of RI elements and limitations on the resources regarding the AMD system installation stipulate the virtual impossibility to equip all RI elements with corresponding sensors. The purpose of this research is to determine a set of elements in the tower-located part of RI to be equipped with corresponding sensors intended to be used in the AMD system, considering the limitations on the resources regarding the AMD system installation. In this research, we propose to apply fuzzy logic to consider assessing the appropriateness of including particular elements in the tower-located part of RI to the elements-under-monitoring (EM) set obtained from a single individual (Mamdani fuzzy inference system) or a group (rank ordering) of experts in the field of the RI operating. Research results yielded recommendations regarding the process of selecting the elements in the tower-located part of RI to be included in the EM set, considering the limitations on the resources regarding the AMD system installation. The AMD system development is out of the scope of the current research. Further studies are needed to provide an economic justification of the AMD system operation based on the EM set.
Digital technologies as modern infrastructure for information support of education and scientific communication: the experience of USUST
(Український державний університет науки і технологій, Дніпро, 2025) Radkevych, Anatolii V.; Kolesnykova, Tetiana O.; Soroka, Maksym L.; Rybalka, Roman V.
ENG: This paper examines the experience of the Ukrainian State University of Science and Technologies in employing digital technologies as a contemporary infrastructure for supporting educational and scholarly communication. It presents a concise overview of the Erasmus+ project “Open science supporting vulnerable communities: empowering university libraries in crisis response” (CAELUM), in which the authors are participants and which materials underpin this study. Within the framework of the CAELUM project, the authors investigated the experiences and expectations of users interacting with the scientific libraries of Ukrainian universities during crises. Anonymised data were collected from 72 respondents aged 18 and above, representing diverse roles within the academic community, through online interviews and questionnaires. Responses to five closed-ended questions were analysed using cluster analysis, resulting in the identification of four distinct respondent clusters. Subsequently, a semantic analysis was conducted on responses to four open-ended questions. The findings enabled the identification of four target user groups of university library services in the context of crisis response. This provides a basis for university libraries to organise their activities more effectively by accounting for the needs and interests of these groups.
Method for Pre-Processing of Level Crossing Image
(Силезский технологический университет, Гливице, Польша, 2015) Rybalka, Roman V.; Honcharov, Kostiantyn V.
ENG: Actuality of problem in the improvement of transport safety at level crossings (LC) is caused by increasing the number of vehicles and reducing discipline of vehicle drivers. One of ways for solution of this problem is associated with using the video surveillance systems for monitoring danger area of level crossing. In such systems due to the limited bandwidth of data channel usually the image compression techniques are used. In this paper the pre-processing method for compression of images is presented. Proposed method accounts unequal subjective informational content of different LC image regions (using fuzzy logic and wavelet transform). Comparison of this method with plain set partitioning in hierarchical trees (SPIHT) technique showed that proposed method allows obtaining better result at image compression in terms of reconstruction quality and compression ratio.
Multi-Valued Automatic Cab Signalling System Based on the CDMA Technology
(Український державний університет науки і технологій, м. Дніпро, 2021) Honcharov, Kostiantyn V.; Rybalka, Roman V.
ENG: Purpose. The work is aimed at the development of principles for the construction of multi-valued automatic cab signalling system (ACS) using the wide-band pseudorandom signals. Methodology. An analysis of existing ACS systems and modern telecommunication technologies has been performed to achieve the stated purpose. The multi-valued automatic cab signalling system CDMA-ACS has been proposed. The mentioned system utilizes wide-band pseudo-noise signals to transmit commands. System parameters: frequency band – 155...395 Hz, pseudorandom codes – 16-bit Walsh codes, spectrum spreading factor – 16, source signal bandwidth – 15 Hz, carrier modulation – DBPSK (differential binary phase-shift keying), information rate – 15 bit/sec, code combination length – 4 bits, maximum amount of commands – 256, the duration of single command transmission – 0.27 sec. Functional diagrams of generator and receiver of the multi-valued automatic cab signalling system have been designed. It has been suggested to apply the correlation method to receive the ACS signals. Findings. To investigate the proposed CDMA-ACS system the simulation modelling has been accomplished in MATLAB in two stages: at the first stage, the CDMA-ACS system was investigated as disturbance-free; at the second stage – under the influence of powerful narrow-band disturbances (traction current harmonics). It has been found that the system shows high immunity to narrow-band harmonic disturbances. The most significant harmonics of the traction current related to the system are 250 Hz and 300 Hz, since they are the closest to the carrier frequency of 275 Hz. It has been determined that errors in decoding the ACS commands occur if the signal-to-noise ratio becomes lower than -8 dB. To reduce the influence of 250 Hz and 300 Hz, harmonics the application of additional band-reject filters was proposed. Originality. For the first time, the authors of this work carried out research on the multi-valued automatic cab signalling system with the use of wide-band pseudo-random Walsh codes. Practical value. Implementation of solutions being proposed allows improving the informativeness and interference immunity for the automatic cab signalling system, reducing the duration of command transmission from the railway track to the cab.
The Power of Open Ideas in the International Academic Library Community
(Державна науково-технічна бібліотека України, м. Київ, 2025-10-23) Kolesnykova, Tetiana O.; Soroka, Maksym L.; Shcherbatiuk, Tetiana H.; Rybalka, Roman V.
ENG: This paper highlights the transformative role of university libraries in advancing Open Science, Open Education, and Citizen Science amid ongoing societal crises and transformations. Drawing on the experience of the Erasmus+ CAELUM project, it demonstrates how libraries are evolving into mediators between academia and society by engaging citizens, students, researchers, and stakeholders in the co-creation of knowledge, data collection, information verification, and crisis response. Special attention is given to the USUST case study on countering disinformation under wartime emergency conditions, where Citizen Science, open data practices, and media literacy are employed to foster resilient and well-informed communities. The presentation also includes findings from a focus group and survey on the role of libraries during crises in Ukraine, confirming the growing importance of libraries as trusted spaces for knowledge co-production, civic participation, and community engagement. It is argued that the power of open ideas lies in the ability of university libraries to build collaborative networks, strengthen collective intelligence, reduce educational and information inequalities, and contribute to sustainable development through Open Science and Citizen Science practices.
Report on focus group discussion and survey results on the role of libraries during crises: The Ukrainian case.
(CAELUM consortium., 2025) Kolesnykova, Tetiana O.; Soroka, Maksym L.; Shcherbatiuk, Tetiana H.; Rybalka, Roman V.
ENG: This report presents the results obtained in Ukraine for WP2A2 of the Caelum project, focusing on the role of university libraries during crises and their contribution to civic engagement and community resilience. Based on a survey and focus groups that brought together the academic community (teachers, students, librarians) and stakeholders, the analysis outlines key priorities, challenges, expectations and opportunities related to crisis response, including countering disinformation in emergency situations in Ukraine.