8 results on '"Matsko, I."'
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2. Simulation of the thermal state of the infinite body with dinamically changing boundary conditions of the third kind
- Author
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Logunova, O. S., Matsko, I. I., and Safonov, D. S.
- Subjects
временной ряд со структурными изменениями ,heat state of the infinite body ,УДК 517.97 ,536.71 [УДК 517.958] ,динамически изменяющиеся граничные условия ,тепловое состояние бесконечного тела ,time series with a variable structure ,граничные условия третьего рода ,boundary conditions of the third kind ,dynamically changing boundary conditions - Abstract
В работе приведена математическая модель для описания теплового объекта при охлаждении в агрегатах зонального типа. Введенные допущения для математической модели позволили выполнить абстрагирование реального объекта к упрощенной форме в виде бесконечного прямоугольного параллелепипеда с динамически изменяющимися граничными условиями третьего рода. Отличительными особенностями модели является описание скоростной компоненты движения фиксированного поперечного сечения в заданный момент времени и функции, задающей значение коэффициента теплоотдачи с поверхности тела в виде временных рядов с переменной структурой. Представлены функциональная схема разработанного программного продукта для проведения вычислительного эксперимента на основе построенной математической модели для исследования поведения температурного поля тела. Выявлено, что изменение скоростной компоненты, связанной с выбором режимов охлаждения, приводит к температурным колебаниям в слоях тела, залегающих на глубине не более 1 см от его поверхностей. Предлагаемая математическая модель может быть использована в автоматизированных системах управления производства непрерывно-литых заготовок при корректировке управления в локальном контуре скорости вытягивания для получения заданного качества продукции. The paper contains a mathematical model to describe the thermal object of cooling in the aggregates of zone type. Imposed by the assumptions for the mathematical model allowed to perform an abstracting of a real object to a simplifed form in the shape as an infinite rectangular parallelepiped with a dynamically variable boundary conditions of the third kind. Distinctive features of the model is to describe the speed components of the movement of a fixed cross-section at a given time and the function that sets the value of the coefficient of heat transfer from the surface of the body in the form of time series with a variable structure. Presents the functional diagram of the developed software for computer simulation based on the constructed mathematical models to research the behavior of the temperature field of the body. It was revealed that the change in speed components associated with the choice of modes of cooling leads to temperature fluctuations in the layers of the body, lying at a depth of not more than 1 cm from the surface. The proposed mathematical model can be used in automated systems control of production continuously cast billets in adjusting the control in the local circuit rate of withdrawal for a given quality of the production. Оксана Сергеевна Логунова, доктор технических наук, профессор, кафедра ≪Вычислительная техника и прикладная математика≫, Магнитогорский государственный технический университет (г. Магнитогорск, Российская Федерация),logunova66@gmail.com. O.S. Logunova, Magnitogorsk State Technical University (Magnitogorsk, Russian Federation). Игорь Игоревич Мацко, аспирант, кафедра ≪Вычислительная техника и прикладная математика≫, Магнитогорский государственный технический университет (г.Магнитогорск, Российская Федерация), matskoigor@gmail.com.I.I. Matsko, Magnitogorsk State Technical University (Magnitogorsk, Russian Federation).Дмитрий Сергеевич Сафонов, аспирант, кафедра ≪Вычислительная техника и прикладная математика≫, Магнитогорский государственный технический университет (г. Магнитогорск, Российская Федерация), dmitry.s.safonov@gmail.com. D.S. Safonov, Magnitogorsk State Technical University (Magnitogorsk, Russian Federation)
- Published
- 2012
3. Social mobility in modern flexible society
- Author
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Matsko, I.
- Subjects
мінливість ,соціальна іммобільність ,соціальна мобільність ,«плинна» сучасність ,соціологія соціальної мобільності - Abstract
У статті аналізуються поняття соціальної мобільності та іммобільності. Останнє становить окремий інтерес, оскільки не так широко вживається у соціології соціальної мобільності. Соціальна мобільність та іммобільність розглядаються у сучасному динамічному суспільстві. В епоху "плинної" сучасності мобільність стає нормою, тим часом це не заперечує існування іммобільного, нерухливого. In the article the concepts of social mobility and immobility are analyzed. The last one is specially interesting, because it is not widely used in sociology of social mobility. Social mobility and immobility in modern dynamic society are considered. Social mobility became a norm in a liquid modernity era. But the existence of immobility is not disclaimed. В статье анализируются понятия социальной мобильности и иммобильности. Последнее представляет отдельный интерес, поскольку не так широко употребляется в социологии социальной мобильности. Социальная мобильность и иммобильность рассматриваются в современном динамичном обществе. В эпоху «текучей» современности мобильность становится нормой, между тем это не отрицает существования иммобильного, неподвижного.
- Published
- 2009
4. Experimental Study of Heat Transfer Rate During Evaporation of Ozone Safe Freon R134a on Plane and Finned Tubes
- Author
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Ovsainnik, A. V., Drobyshevski, D. A., Valchenko, N. A., Shapovalov, A. V., Gurikov, D. A., and Matsko, I. I.
- Subjects
Criterion equation ,Heat transfer ,Freon-134a ,Boiling ,Ribbing tube - Abstract
Experimental definition of heat transfer rate during developed nucleate boiling of freon – 134a on plane and longitudinally finned tubes in the conditions of pool boiling in the range of heat fluxes of 8–63 kW/m2 at saturation pressures of ps = 0.5–0.8 MPa has been provided. The criterion equations are obtained enabling to calculate the heat transfer rate on horizontal plane technically rough tubes for the conditions of experiments.
- Published
- 2008
5. Forecasting of Image Processing Time using Deterministic Methods
- Author
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Matsko, I. I., primary and Logunova, O. S., additional
- Published
- 2012
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6. Data acquisition, preparation and processing methodsby means of continuously-casted billets'quality analysis software
- Author
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Matsko, I. I., primary, Snegirev, Y. V., additional, Pavlov, V. V., additional, Kovaleva, E. S., additional, and Logunova, O. S., additional
- Published
- 2011
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7. Hilbert transform for covariance analysis of periodically nonstationary random signals with high-frequency modulation.
- Author
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Javorskyj I, Yuzefovych R, Lychak O, and Matsko I
- Abstract
We discuss the use of the Hilbert transform for the analysis of periodically non-stationary random signals (PNRSs), whose carrier harmonics are modulated by jointly stationary high-frequency narrow-band random processes. PNRS of this type are suitable models for numerous natural and man-made phenomena, including the vibration of a damaged mechanism. We show that the auto-covariance function of the signal and its Hilbert transform are the same, and that their cross-covariance functions differ only in their sign, meaning that the sum of squares of the signal and its Hilbert transform cannot be considered a 'squared envelope' and no new information is contained compared with the variance of the raw signal. A representation of the signal in the form of a superposition of high-frequency components is obtained and it is shown that these components are jointly periodically non-stationary random processes. The properties of the band-pass filtered signals are examined, and it is shown that band-pass filtering can reduce both the number of signal variance cyclic harmonics and their amplitudes. We show that it is possible to extract the quadratures of narrow-band high-frequency modulation processes using the Hilbert transform. The results obtained here theoretically substantiate the use of the Hilbert transform for the analysis of high-frequency modulation which occurs when a fault appears. They offer a new way to consider the traditional approach to vibration diagnosis. A processing technique that can be considered an alternative to envelope analysis is described, and its use in the analysis of a vibration signal is discussed., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Roman Yuzefovych reports was provided by Karpenko Physico-mechanical institute of NAS of Ukraine. Roman Yuzefovych reports a relationship with Karpenko Physico-mechanical institute of NAS of Ukraine that includes: employment., (Copyright © 2023 ISA. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
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8. Methods of Hidden Periodicity Discovering for Gearbox Fault Detection.
- Author
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Javorskyj I, Matsko I, Yuzefovych R, Lychak O, and Lys R
- Abstract
It is shown that the models of gear pair vibration, proposed in literature, are particular cases of the bi-periodically correlated random processes (BPCRPs), which describe its stochastic recurrence with two periods. The possibility of vibration and analysis within the framework of BPCRP approximation, in the form of periodically correlated random processes (PCRPs), is grounded and the implementation of vibration processing procedures using PCRP techniques, which are worked out by the authors, is given. Searching for hidden periodicities of the first and the second orders was considered as the main issue of this approach. The estimation of the non-stationary period (basic frequency) allowed us to carry out a detailed analysis of the deterministic part, the covariance structure of the stochastic part, and to form, using their parameters, the sensitive indicators for fault detection. The results of the processing of the wind turbine gearbox vibration signals are presented. The amplitude spectra of the deterministic oscillations and the time changes of the stochastic part power for different fault stages are analyzed. The most efficient indicators, which are formed using the amplitude spectra for practical applications, are proposed. The presented approach was compared with known in literature cyclostationary analysis and envelope techniques, and its advantages are shown.
- Published
- 2021
- Full Text
- View/download PDF
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