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Influence of Technological Methods of Processing on Wear Resistance of Conjugated Cylindrical Surfaces
(Springer, Cham, 2021) Zablotskyi, Valentyn; Tkachuk, Anatolii; Moroz, Serhii; Prystupa, Stanislav; Svirzhevskyi, Kostiantyn
Wear of any tribological pair leads to malfunction or failure of the entire mechanism. It is known that the process of wear of friction pairs occurs in three periods: running-in, normal wear, accelerated wear (destruction). Working surfaces of parts that are formed in the manufacturing process receive micro geometric characteristics (roughness, undulation), according to the regulated technological norms. These characteristics describe the properties of the technological surface topography. However, quantitative micro geometric parameters change as they evolve during running-in, and the surface receives a new operational relief that is stable for a long time during normal wear. It is an operational relief of conjugate surfaces that characterizes the qualitative properties of parts for a long period of operation. The running-in process, which is based on complex mechanical, physical, and chemical processes, determines the overall wear resistance of parts. After this period, the physical, mechanical, and geometric characteristics of the surface acquire optimal values corresponding to the operating conditions. Rational performance characteristics during normal wear can self-sustain, and they are continuously reproduced independently in the same values. This state of the surface layer is observed before the beginning of the third stage of the life cycle. Traditionally, to ensure regulated micro geometric characteristics of the working surfaces used grinding, smoothing, and lapping diamond pastes. At the present stage of development of equipment and technology in a row with the mentioned finishing operations, there is an operation of high-speed turning, which allows reaching high purity of surfaces with the lowest cost of the technological process.
Modeling the Dynamics of Centerless Mortise Grinding on Rigid Supports
(2025) Chalyj, Vasyl; Moroz, Serhii; Tkachuk, Anatolii; Zablotskyi, Valentyn; Zabolotnyi, Oleg
The paper examines the influence of the dynamic parameters of the machine and the geometry of the adjustment of rigid supports on the formation of undulations of the surfaces of roller bearing rings. A complex mathematical model of the machine tool system for centerless mortise grinding was developed, and the influence of the dynamic parameters of the machine tool and the geometry of the setup of rigid supports on the formation of undulations of the processed surfaces was analyzed. The SWaAGL-50 mortise centerless grinding machine’s technological system is presented as a linear mechanical model, and the elastic movements along the ОХ axis are considered. Based on the equations of kinetic and potential energies compiled in the form of Lagrange, the equations of motion of the relevant elements of the technological system were obtained. The formula of the dynamic accuracy function was found, which characterizes the inconsistency of the movement of the grinding wheel and the part.
MONITORING OF LINK-LEVEL CONGESTION IN TELECOMMUNICATION SYSTEMS USING INFORMATION CRITERIA
(2022-12-30) Yakymchuk, Natalia; Selepyna, Yosyp; Yevsiuk, Mykola; Prystupa, Stanislav; Moroz, Serhii
The successful functioning of telecommunication networks largely depends on the effectiveness of algorithms for detection andprotection against overloads. The article describes the main differences that arise when forecasting, monitoring and managing congestion at the node levelandat the channel level. An algorithm for detecting congestion by estimating the entropy of time distributions of traffic parameters is proposed.The entropy measures of data sets for various types of model distribution, in particular for the Pareto distribution, which optimally describes the behaviorof self-similar random processes, were calculated and analyzed. The advantages of this approach include scalability, sensitivity to changes in distributionsof traffic characteristics and ease of implementation and accessible interpretation.
DEVELOPMENT OF A MODIFIED METHOD OF NETWORK TRAFFIC FORMING
(2023-03-31) Kozlovskiy, Valeriy; Yakymchuk, Natalia; Selepyna, Yosyp; Moroz, Serhii; Tkachuk, Anatolii
Based on the analysis of the statistical characteristics of heterogeneous network traffic of "Quadruple Play" mobile subscribers, it is shown that it cannot be represented by Poisson or Erlang distributions. It is shown that for such similar traffic, the rate of growth of the required buffer volume increases as the Hurst parameter increases. A method of adaptivetraffic formation using the control of the length of intervals of the intensity of the arrival of data packets has been developed. Congestion management is carried out by changing the frequency of the marker generator (GM) on the basis of the results of forecasting the required bandwidth of the system and the required buffer size. The shaper adapts to changes in the length and instantaneous intensity of packet input in real-time.

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