The scientific journal http://elar.nung.edu.ua/handle/123456789/6383 2026-04-05T15:37:38Z 2026-04-05T15:37:38Z Lytvynenko, I. V. http://elar.nung.edu.ua/handle/123456789/7352 2019-11-09T01:00:25Z 2017-01-01T00:00:00Z

Title: The method of segmentation of stochastic cyclic signals for the problems of their processing and modeling Authors: Lytvynenko, I. V. Abstract: The segmentation method (signal partitioning into specific sections, segments) of a cyclic stochastic signal is considered. Taking into account cyclicity attributes, segmental cyclic and segmental zone structure, there is proposed a method for solving the segmentation problem of a cyclic stochastic signal with a stable or replaceable rhythm. The information obtained on the segment structure allows us to analyze the rhythm: to estimate the value of the period in the case of a stable rhythm, and in the case of a variable rhythm - the rhythmic structure (discrete rhythm function). There are given the examples of segmentation of modeled and real cyclic signals, and the accuracy of the developed segmentation method is estimated. The developed method can be used in digital process automation systems (diagnostics and forecasting) of cyclic data: cardiac signals of various physical nature, cyclic economic processes, gas consumption and energy consumption processes, surface processes of relief formations of modern materials.

2017-01-01T00:00:00Z Panchuk, M. V. Shlapak, L. S. Theremko, N. Szkodo, M. Kiełczynski, W. Kishka, S. O. http://elar.nung.edu.ua/handle/123456789/7351 2019-11-09T01:00:22Z 2017-01-01T00:00:00Z

Title: Study of the influence of thermal factors on the welding process of polyethylene gas pipelines Authors: Panchuk, M. V.; Shlapak, L. S.; Theremko, N.; Szkodo, M.; Kiełczynski, W.; Kishka, S. O. Abstract: A one-dimensional calculation scheme is proposed with the help of which it is possible to determine and set the technological parameters with the accuracy to be realized in production conditions: the temperature of the heating element and the heating time, which allows maximum mechanization of the technological operations of polyethylene gas pipelines welding. The numerical value of the coefficient of temperature for polyethylene grade PE-80 is determined and it is found that the presence of molten polymer mass at the ends of pipes is an additional source of their heating and a significant factor in obtaining high quality and reliable welds.

2017-01-01T00:00:00Z Klyun, A. Karpash, M. Trebulova, I. Kogut, G. http://elar.nung.edu.ua/handle/123456789/7350 2019-11-09T01:00:27Z 2017-01-01T00:00:00Z

Title: Experience of operation of electronic database of full-text standards HAMMER in PJSC "Ukrtransgaz" Authors: Klyun, A.; Karpash, M.; Trebulova, I.; Kogut, G. Abstract: In the article, the mechanism of effective normative document provisioning is comprehensively studied, statistical studies on the use of various NDs types in the Company are analyzed; the indicators of the priority use of NDs are analyzed; development and improvement trends of the regulatory base for gas transmission industry of Ukraine following the abolition of the standards of the former USSR and the introduction of modern European and international standards in Ukraine are highlighted. The aim of this study is to represent the results of implementation of an electronic data-retrieval system of full-text operating normative documents in PJSC “Ukrtransgaz”, emphasizing on the necessity of upgrading the existing normative documents. The paper demonstrates a relatively new approach to management of standards necessary for operation of a big service provider in the gas supply sector of Ukraine.

2017-01-01T00:00:00Z Doroshenko, Ya. V. Pylypiv, L. D. Poliarush, К. А. Doroshenko, Yu. І. http://elar.nung.edu.ua/handle/123456789/7349 2019-11-09T01:00:26Z 2017-01-01T00:00:00Z

Title: The study of the stress-strain state of trunk gas pipeline sections with defects in the shape of the cross-section of the pipe Authors: Doroshenko, Ya. V.; Pylypiv, L. D.; Poliarush, К. А.; Doroshenko, Yu. І. Abstract: There is carried out 3D modeling of the trunk gas pipeline sections with defects in the cross section shape of the pipe - dents and ovalities. The ANSYS Fluent R18.0 Academic software packge simulates gas flow through these sections of the gas pipeline. The mathematical model of the gas motion is based on the solution of the Navier–Stokes equations and the energy transfer, closed by a two-parametric model of the Launder–Sharma turbulence, using a wall function with corresponding initial and boundary conditions. The structure of the gas flow in the sections of the gas pipeline with defects of the cross section shape of the pipe is investigated. The simulation results were visualized by designing flow lines, the fields of velocity and pressure modules on the contours, in longitudinal and cross-sectional sections. The exact values of velocity and pressure at different points of the inner cavity of gas pipeline sections with defects in the cross-section shape were determined. The places of slowdown and acceleration of gas flow, increase and decrease of pressure were found.

2017-01-01T00:00:00Z