Browsing by Author "Vernigora, Roman V."
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Item 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.).Item Creation of Export-Oriented Network of Grain Elevators in Ukraine(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Kozachenko, Dmytro M.; Vernigora, Roman V.; Rustamov, Rustam S.ENG: Purpose. The scientific paper highlights improving the efficiency of export rail transportation of grain cargoes in Ukraine by introducing shipper routing and concentration of loading at the terminal grain elevators. Methodology. According to the experience of the USA and Canada, one of the most effective ways to reduce costs in the grain to-port supply chain is a shipper routing of the rail traffic. Shipper routing for transportation of grain cargoes involves the concentration of their loading on the multiple junctions. The junctions are proposed to be selected with the use of cluster analysis methods. For the formation of the grain loading concentration areas the authors used methods of set theory and multi-criteria optimization. Findings. Based on agglomerative cluster analysis algorithm, the junctions on a network of Ukrainian railways are selected and the areas of possible concentration of grain loading are formed. DSU-algorithm allowed distinguishing the overlapping and non-overlapping areas of concentration. The problem of selecting non-overlapping areas of the grain loading concentration is formalized as the problem of multiobjective integer programming with boolean variables. The solution of this problem by a modified simplex algorithm allows selecting on the railway network of Ukraine 24 districts of possible grain loading concentration, which cover 70 stations and at minimal additional cost provide routing of about 7.5 million tons of grain per year. Originality. The originality of the work lies in the fact that the authors developed the mathematical procedure for selection of junctions and concentration areas of grain loading at the Ukrainian railway network, taking into account the economic efficiency of the process. Practical value. Application of the developed method of grain loading concentration for the formation of unit trains will significantly reduce the logistics costs in the supply chain of grain to Ukrainian ports for export and, consequently, increase its competitiveness in foreign markets.Item Determining Patterns of Vertical Load on the Prototype of a Removable Module for Long-Size Cargoes(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Vatulia, Glib; Lovska, Alyona O.; Pavliuchenkov, Mykhailo; Nerubatskyi, Volodymyr; Okorokov, Andrii; Hordiienko, Denys; Vernigora, Roman V.; Zhuravel, IrinaENG: The object of this study is the processes of occurrence, exposure to, and redistribution of loads in the supporting structure of a removable module for the transportation of long cargoes. To adapt platform cars to the transportation of long loads, it is proposed to introduce a removable module with elastic-friction connections in the structure. In order to select the optimal profiles for the removable module, in terms of minimal material consumption, the calculation was carried out in the Lira software package. Based on the calculation results, a spatial model of the concept of the removable module was built. To determine the dynamic loads that act on the platform car loaded with a removable module, a mathematical simulation was carried out. It was established that the use of elastic-friction links in the structure of the removable module helps reduce its dynamic load, as well as the platform car, by 4.6%. The resulting acceleration was taken into account when calculating the strength of the removable module. The calculation results showed that the strength of the removable module under operational loads is ensured. A feature of the reported results is that the proposed design of a removable module makes it possible not only to adapt the plat-form car to the transportation of long loads but also to reduce its load in operation. The scope of practical application of the results includes the engineering industry, in particular, railroad transport. Worth noting is that the conditions for the practical use of the results imply the introduction of elastic-friction links in the structure of the removable module. The reported research will contribute to compiling recommendations for the design of modern vehicle structures, in particular removable type, as well as for improving the efficiency of rail transportation.Item Evaluation of the Transition to the Organization of Freight Trains Traffic by the Schedule(Silesian University of Technology, Poland, 2016) Kozachenko, Dmitriy N.; Vernigora, Roman V.; Balanov, Vladimir O.; Berezovy, Nikolay I.; Yelnikova, Lidiia O.; Germanyuk, Yuliya N.ENG: The paper considers the issues of bulk conveyance organization between industrial enterprises on schedule. Currently the movement of the main part of freight trains is performed on preparedness and occupation processes of separate schedule train paths by some terminals are not fixed. And, due to the lack of statistical material on the punctuality of the schedule for the movement of freight trains, research of the passenger trains movement with subsequent dissemination of results on freight movement were carried out by the authors. The values of the additional time reserves that should be included in the schedule of trains, and the schedule for the turnover of freight trains to provide conditional interaction of railroads and industrial enterprises in Ukraine were proposed. The obtained results can be used for the technical-and-economic calculations of transition effectiveness of industrial enterprises for maintenance on schedule as well as in the development of schedule on the initial stages of testing technology.Item Functional Simulation of Railway Stations on the Basis of Finite-State Automatа(Silesian University of Technology, Poland, 2014) Bobrovskyi, Volodymyr I.; Kozachenko, Dmytro M.; Vernigora, Roman V.ENG: The general scheme of railway station’s model and technique of formalizing the technologic processes at stations are described. To take into account the human impact on station’s operation is suggested to use ergatic models. In conformity with concept of stations’ ergatic models a person is directly involved into the simulation process and manages the station technological processes acting as a dispatcher. The formalization of technological processes for processing the objects is performed on the basis of deterministic finite-state automaton. Designed model can be used for optimization of technical and technological parameters of railway stations, as well as in computer simulators for training of railway traffic managers.Item Improving the Methods of Estimation of the Unit Train Effectiveness(Silesian University of Technology, Poland, 2016) Kozachenko, Dmytro M.; Vernigora, Roman V.; Balanov, Volodymyr O.; Sannytskyy, Nazar М.; Berezovy, Nikolay I.; Bolvanovska, Tetiana V.ENG: Summary. The article presents the results of studies of freight transportation by unit trains. The article is aimed at developing the methods of the efficiency evaluation of unit train dispatch on the basis of full-scale experiments. Duration of the car turnover is a random variable when dispatching the single cars and group cars, as well as when dispatching them as a part of a unit train. The existing methodologies for evaluating the efficiency of unit trains’ make-up are based on the use of calculation methodologies and their results can give significant errors. The work presents a methodology that makes it possible to evaluate the efficiency of unit train shipments based on the processing of results of experimental travels using the methods of mathematical statistics. This approach provides probabilistic estimates of the rolling stock use efficiency for different approaches to the organization of car traffic volumes, as well as establishes the effect for each of the participants in the transportation process.Item Research into a Possibility to Prolong the Time of Operation of Universal Semiwagon Bodies that Have Exhausted Their Standard Resource(НВП ПП «Технологічний Центр», Харьків, 2018) Okorokov, Andriy M.; Fomin, Oleksij V.; Lovska, Alyona O.; Vernigora, Roman V.; Zhuravel, Irenа L.; Fomin, Volodimir V.ENG: The intensification of utilization of railroad cars predetermines the wear of their bodies as the most loaded element of design and necessitates the introduction of new cars. To reduce the cost of manufacturing new car designs, it is proposed to prolong the operation of universal open top wagon bodies beyond standard 1.5 operation terms. When carrying out calculations for strength under conditions of wagon building enterprises, the normative magnitudes of loading are applied, which do not take into consideration possible wear in the elements of bearing structures of open top wagon bodies under operation. This can lead to a significant error when determining a possibility to extend a period of operation of open top wagon bodies that have exhausted their standard resource. Therefore, when substantiating a possible prolongation of the operation period of cars it is important to take into consideration, at the stage of strength estimations, the refined magnitudes of dynamic loads acting on them in operation. To investigate dynamic loading acting on a open top wagon body during an impact at shunting, which is the case of the greatest loading to its structure, we employed mathematical modeling. The results of present research allowed us to conclude that the acceleration that acts on the bearing structure of a open top wagon with the wear characteristic of 1.5 terms of operation during an impact at shunting is about 4g. In addition, research into dynamic loading of the bearing structure of a open top wagon body during an impact at shunting was performed using computer simulation based on the software CosmosWorks. The research results showed that the maximum accelerations of a open top wagon body make up approximately 5g. To verify the adequacy of the developed models, we used the Fisher criterion. Results of the calculations have shown that the hypothesis of adequacy is not contradicted. The research results obtained were taken into consideration when determining strength indicators of a open top wagon body with the wear characteristic of 1.5 terms of operation. To this end, we constructed a spatial computer model of the body of a base open top wagon, model 12-757, whose bearing elements are of the thickness corresponding to the minimally defined one. The calculation employed a method of finite elements. Based on the performed calculations it was determined that the maximum equivalent stresses do not exceed the permissible ones and make up about 345 MPa, which makes it possible to draw a conclusion about the possibility of further utilization of a railroad car. The study conducted would help determine the feasibility of prolongation of service operation of open top wagons that have exhausted their standard resource.Item Researching Operation of the Railway Stations with Using of Their Ergatic Simulation Models(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2013) Bobrovskyi, Volodymyr I.; Kozachenko, Dmytro M.; Vernigora, Roman V.ENG: The general scheme of railway station’s model and technique of formalizing the technologic processes at stations are described. Designed model can be used for optimization of technical and technological parameters of railway stations, including with using the grapho-analitical method.Item Resource-Saving Technologies of Railway Transportation of Grain Freights for Export(Politechnika Warszawska; Instytut Transportu, 2018) Kozachenko, Dmitrii N.; Vernigora, Roman V.; Kuznetsov, Valeriy; Lohvinova, Nataliia A.; Rustamov, Rustam S.; Papahov, Aleksandr Yu.ENG: The research objective is to increase the efficiency of export railway transportation of grain freights in Ukraine by the introduction of consignor routing, a concentration of loading of grain on junction elevators and the organization of the movement of grain routes according to the schedule. According to the researchers in USA and EU, one of the effective directions for decreasing the expenses in a logistic chain of grain delivery to ports is consignor routing of railway transportation. Consignor routing of transportations of grain freights provides a concentration of their loading at junctions. The choice of junctions is proposed to be carried out on the basis of methods of the cluster analysis. For formation of regions for a concentration of grain loading the theory of sets and multicriteria optimization are used. As a result, on the basis of the modified simplex method are chosen 24 regions of possible concentration of grain loading that cover 70 stations on Ukrainian railways providing 7,5 million t consignor routing for grain in a year with minimal additional expenses. The assessment of the efficiency of railway transportation routing of grain freights is calculated with use of the developed simulation model. Researches showed that application of consignor routing allows to reduce a turn-round cycle for grain wagon in a logistic chain of deliveries up to 27%, and application of the schedule for consignor routes allows to reduce a turn-round cycle up to 62%, in comparison with transportation by car loading. Thus, as showed the calculations executed for one of the directions of grain transportation for export, the necessary operation park of grain-carrier wagons is reduced twice, thereby allowing to cut logistic expenses on a delivery of the Ukrainian grain through seaports to the world markets.