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Item type:Наукова стаття, 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, KostiantynWear 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.Item type:Наукова стаття, Modeling the Dynamics of Centerless Mortise Grinding on Rigid Supports(2025) Chalyj, Vasyl; Moroz, Serhii; Tkachuk, Anatolii; Zablotskyi, Valentyn; Zabolotnyi, OlegThe 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.Item type:Наукова стаття, Analysis of Technical Characteristics of Temperature Sensors for the Design of Medical Thermometers(2023-10-13) Moroz, Serhii; Tkachuk, Anatolii; Zablotskyi, Valentyn; Prystupa, Stanislav; Lyshuk, Viktor; Talakh, ValentynThe paper analyzes the technical features that must be taken into account during the construction of medical thermometers. An analysis of thermometers was carried out from the point of view of their suitability for monitoring temperature fluctuations on the surface of a biological object. The dependence of the resolution of the thermometer for different temperature ranges is considered. Expanding the range of measured temperatures leads to a decrease in the transmission coefficient, and vice versa, a decrease in the range leads to an increase in the steepness by the same number of times. A comparative analysis of various types of temperature sensors was carried out, in particular, a temperature-voltage converter (TC1047) from Microchip in a SOT23 case, a thermosensor (SMT16030) from Smartec in a TO18 case, a thermistor (203JG1F) from NTC in a DO35 case, (LM19) from National Semiconductor in a TO92 case, and (TSIC306) by Hygrosens in the SO8 case. The informativeness coefficients of the conversion of thermal sensors, and the dependence of the thermal time constant on the mass of the sensor in different types of housing are considered. It has been established that thermometers with sensors based on semiconductor diodes have a high perspective since sensors of this type provide high speed, short response time, operation in the mode of microcurrents, which maximally reduce self-heating of the sensor, high sensitivity, good linearity in a given temperature range (25...40°C), stability of electrical parameters. Along with high operational characteristics, sensors based on a semiconductor diode have a low cost.Item type:Наукова стаття, MONITORING OF LINK-LEVEL CONGESTION IN TELECOMMUNICATION SYSTEMS USING INFORMATION CRITERIA(2022-12-30) Yakymchuk, Natalia; Selepyna, Yosyp; Yevsiuk, Mykola; Prystupa, Stanislav; Moroz, SerhiiThe 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.Item type:Наукова стаття, DEVELOPMENT OF A MODIFIED METHOD OF NETWORK TRAFFIC FORMING(2023-03-31) Kozlovskiy, Valeriy; Yakymchuk, Natalia; Selepyna, Yosyp; Moroz, Serhii; Tkachuk, AnatoliiBased 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.