Перегляд за автором "Nikitenko, O. M."
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Публікація Distribution of electrostatic potential in crossed–field system with complex electrodes’ configuration(2000) Nikitenko, O. M.The most important problem, which represent of practical interest for specialists of UHF electronics and electrodynamics, is problem adequate describing of physical process occur in crossed-field systems. The most difficult problem is solution Laplace equation with complex boundary conditions. Here it was described the solution process of Laplace equation for defining electrostatic contribution potential for systems with complex geometry.Публікація Does a Diocotron Effect Exist in Magnetrons?(2022) Moshchenko, I. O.; Nikitenko, O. M.In this article magnetron model has been developed for explanation why the electron beam had wavelike form before oscilation stage. As well known in crossed-field devices electrons move by cycloid-like trajectories. In accordance with the diocotron effect electron beam form has wavelike form because interaction between RF wave and electron beam. But at preoscillation stage we had the same electron beam form in magnetron both planar and cylindrical. Such form we explained by space periodical distribution of an electrostatic potential distribution.Публікація Influence of construction parameters of crossed–field devices resonant structure on quality factors(Вебер, 2012) Chen, Xin; Nikitenko, O. M.Quality factors of magnetron resonant structure via geometrical parameters were analyzed. Using the oven magnetron as a base it was defined the influence of geometrical parameters on quality factors in particular neighbouring mode separation.Публікація Linearized Approach of Crossed–Field Devices(IEEE, Monterey, 2014) Korchakova, A. S.; Nikitenko, O. M.Публікація Passing Power Sensors and Multiprobe Microwave Multimeter on Its Base(SPIE, 2006) Volkov, V. M.; Nikitenko, O. M.; Zaichenko, O. B.; Zharko, Yu. G.; Isichko, A. L.The mathematical modeling of thin wall waveguide heating process allows to determine the law of temperature field distribution on their surface. The new physical models of sensors on the absorbing wall principle in the coaxial transmission line were proposed and dissipative losses dependence on frequency in one, two and three layer absorbing wall was analyzed. Methods of calculation and designing of the both quasipoint and extended sensors, located on the narrow and wide waveguide walls were proposed: minimization of effective reflection.Публікація Possibilities of using SMS Maple to study random variable distribution laws(ХНУРЕ, 2021) Moshchenko, I.; Nikitenko, O. M.; Kozlov, Yu.The use of CMS Maple for students' practical and independent work is described. The study of random variable distribution laws is actual. Statistical calculations without computer are difficult and require many functional and quintiles tables of standard distributions. This does not contribute to feeling the element of novelty in the material being studied, to be able to arbitrarily change the conditions of tasks, etc., it takes a lot of time in solving applied production problems, which is inappropriate Thus to determine and research random variable distribution laws both in practical applications and in studying we must use special mathematical packages. The most extended of them are Mathcad, MatLab, Mathematica, Maple. Specialized statistical packages (SAS, SPSS, STATISTIKA, STATGRAPHICS) are not relevant to study. Their use for studying requires very high education level in mathematical statistics. Most of the existing math packages allow users to operate at random variables, including the Computer Mathematics System (CMS) Maple. Thus, the purpose of this article is a description of the studying possibilities of the random variables distribution laws with CMS Maple and the application of the acquired skills to the independent work of students. The Maple Statistics Library has a large set of commands for analyzing data, computing various numerical characteristics of random variables, graphing their distribution laws, and for statistical data processing. Thanks to a powerful set of statistical tools, the possibility of symbolic calculations and data processing of CMS Maple, wide possibilities of graphical interpretation of the results obtained not only in a static but also in a dynamic form, it is advisable to use it when studying the topic "Distribution Laws of Random Variables" in students' practical and independent work to use their acquired skills in solving applied problems of science and technology.Публікація Simplified Approach to Modeling of Cross–Field Devices(Begell House Inc, 2014) Nikitenko, O. M.; Volovenko, M. V.The possibility to adapt the cross-field devices systems to the linearized one is presented. This simplification makes it possible to simplify significantly the study of certain processes in such systems. It is shown that the error of this simplification does not exceed 2%. This approach makes it possible to estimate the space-charge oscillation frequencies.Публікація The experimental research of magnetron output spectrum components(2013) Chen, Xin; Nikitenko, O. M.; Yevseev, P. M.Output spectral components radiated from magnetrons were experimentally measured. It was found correlation with some oscillations which influence on electromagnetic surrounding. As quality factors were proposed number of outside components and their magnitudes.Публікація The interaction of oscillations in Crossed-Field Devices(Seventeenth IEEE International Vacuum Electronics Conference IVEC 2016 April 19-21, 2016 Monterey, 2016) Kuznichenko, V. V.; Nikitenko, O. M.; Volovenko, M. V.There were observed two models of crossedfield devices. The interaction between fundamental, ion and space charge oscillations caused to spectrum enrichment and chaotization. The comparison both theoretical and experimental results had good congruent.Публікація Using of linearized approach for crossed–fields devices’ modeling(Вебер, 2013) Korchakova, A. S.; Nikitenko, O. M.Using of linearized systems describing the crossed–fields devices’ operation, taking into account space charge fields, is studied. It allowed simplifying significantly the processes study in crossed-fields devices. It was shown that one of spectrum components coincides with the fundamental mode of magnetron oscillations. Рассмотрено использование линеаризованных систем, описывающих работу приборов со скрещенными полями с учетом полей пространственного заряда. Это позволяет значительно упростить изучение процессов, протекающих в приборам со скрещенными полями. Показано, что одна из составляющих энергетического спектра совпадает с основной модой колебаний магнетрона.Публікація Value stream map optimization model in the field of educational services(2023) Moshchenko, I. O.; Nikitenko, O. M.The relevance of the implementation the Lean Production quality management model in higher educa tion institutions (HEIs) in Ukraine has been proven to optimize the stream of HEIs business processes in order to improve the quality of functioning of HEI as an economic activity subject and increase the compete tiveness of educational services, scientific and educational products. The modern approaches of scientists to the Lean Higher Education and the construction of a process model of activity and the identification of key business processes of HEIs are analyzed. The purpose of the article is to develop the optimization model for the stream of business processes based on Lean technologies and to apply the model to visualize and optimize the key process of business process at the Kharkiv National University of Radio Electronics (NURE). A DFD model of the optimization process of the Value Stream Map (VMS) - a quality management tool created within the framework of the Lean methodology for process stream analysis - was developed. The model optimization criteria are proposed. During the development of the map optimization model, the peculiarities of the result of the HEI activity, which is a combination of educational service, educational and scientific product, were taken into account. The practical significance of the article lies in the study of the HEI key process "Development of educational and methodological support of the educational process". Decomposition of the main process was carried out. The second and third levels processes for the value stream mapping was distinguished. The current state VSM of the process "Development of educational and methodological support of the educational process" was developed, the indicators of the effectiveness of the value stream at the department of information and measurement technologies of the NURE were calculated, the "bottlenecks" of the stream were analyzed. Measures to optimize "bottlenecks" based on the criterion of minimizing time are proposed. Prospects for further research in the chosen direction are determined as the implementation of Lean technologies in the activities of HEIs are the development and optimization of VSM for all key processes of HEIs.Публікація What Types of Space Charge Are Inherent to Different Models of Crossed-Field Devices?(2023) Moshchenko, I.; Nikitenko, O. M.; Volovenko, M.In this article four models of crossed-field devices: planar magnetron diode, planar magnetron, magnetron diode and magnetron were described. As well known in crossed-field devices electrons moved by cycloid-like trajectories and formed space charge. The shape of the space charge depends on the model under consideration. In a planar magnetron diode the space charge formed as a flow that is parallel to the electrodes. In a planar magnetron the space charge is not formed and is determined by the anode current only. In a magnetron diode the space charge formed as a flow that is parallel to the electrodes. In a magnetron the space charge is not formed and is determined by the anode current only.