Browsing by Author "Papakhov, Oleksandr Yu."

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    Capital Investments in the Context of Sustainable Development of Railways
    (Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Kharchenko, Olesia I.; Okorokov, Andrii; Vernigora, Roman V.; Tsuprov, Pavlo; Papakhov, Oleksandr Yu.; Logvinova, Nataliia A.
    ENG: Abstract. Ukraine, due to its geographical position and developed transport infrastructure, has significant potential as a transit country, primarily in the supply chain of trade between Asia and Europe. According to the estimates of the British Institute for Transport Rendell Ukraine, the transit coefficient of Ukraine is 3,75 (with a maximum of 5); This is the best indicator among the countries of Europe (for comparison, in Poland, which occupies the second place, this indicator is 2,92). Nowadays, Ukraine uses its transit potential extremely insufficiently and inefficiently; over the past 10 years, the volume of transit traffic through the territory of Ukraine has declined by more than 2,5 times, primarily due to the fall in transit traffic by rail. One of the reasons for this situation is, of course, the general political and economic situation in the country. However, there are a number of other negative factors that prevent Ukraine from fully and effectively using its transit potential. These problems lie both in the purely technical plane (deterioration of transport infrastructure and rolling stock, lack of capacity of the main transport routes, underdevelopment of logistics terminals in the country and at land borders, difference in width with the European railway system) and the legislato-thick (high level of port dues, bureaucratization and regulation of customs procedures, lack of flexible tariff policy for carriers, etc.).
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    A New Method for Solving the Problem on the Organization of Wagon Flows Under Condition of Energy Efficiency of Transportation
    (НВП ПП «Технологічний центр», м. Харків, 2017) Papakhov, Oleksandr Yu.; Logvinova, Nataliia A.; Kharchenko, Olesia I.; Milyanych, Andriy R.; Sichenko, Victor G.
    ENG: The paper considers solving a problem of rational organization of wagon flows in a polygon of selected technological rail-road stations using a technique for solving a knapsack problem employing set functions. Based on the results of present work, the authors developed a method for solving a knapsack-type problem that makes it possible to adapt the algorithm of solving a vector optimization problem to the rational system of organizing wagon flows in trains without using differentiation operations and to solve a basic optimization problem employing the Lagrange multipliers. The applicability of the Lagrange method was proved for the problems on a conditional extremum in terms of set functions. Its special feature is the rejection of Boolean variables. We confirmed correctness of the mathematical notation of solution to a knapsack-type problem and proved adequacy of the proposed algorithm, as well as adapted it for adjusting a plan of freight trains formation in order to improve energy efficiency of transportation. By reducing the complexity of the problem, it has become possible to reduce computer processor time needed for calculation, and employ this algorithm when designing an automated work place (AWP) for an engineer responsible for planning the formation of trains. It should be specially noted that a reduction of the time needed to solve a problem makes it possible to timely adjust the plan of freight trains formation, to eliminate a lot of irrational variants when handling wagons at technical stations. The proposed algorithm helps identify variants to direct train flows to the most promising destinations at minimal energy cost for transportation. Limitations of the proposed approach include a closed cycle of routes of the loaded wagons and part of these routes traveled unloaded until the next load¬ing. In some cases, there is a need to change a weight of the train composition, associated with fractures of weight, and, therefore, a change in the balance between wagon flows and train flows.
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    Optimization of Traction Power Supply System with Variation of Train Flow Sizes
    (Kaunas University of Technology, Kaunas, Lithuania, 2020) Kuznetsov, Valeriy; Hubskyi, Petro V.; Sychenko, Viktor G.; Kosariev, Yevhen M.; Papakhov, Oleksandr Yu.; Bekh, Petro V.
    ENG: Modern requirements for the operation of electrified railways are the efficient use of available technical means to ensure energy efficiency while increasing train traffic. The aim of the work is to substantiate the optimization of the structure of the DC traction power supply system with variation of train flows and traction loads. Such optimization should be performed after the reformatting of the train schedule and the subsequent impossibility of increasing the energy performance. The methodological basis for the optimization of the existing power supply system of the traction line is the use of a hybrid traction power supply system with an asymmetric arrangement of active generators.