Browsing by Author "Kozachenko, Dmytro M."
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Item Adaptation of Ukrainian Grain Elevators for Unit Train Loading(Kaunas University of Technology, Kaunas, Lithuania, 2018) Kozachenko, Dmytro M.; Bobrovsky, Volodymyr I.; Ochkasov, Oleksandr B.; Shepotenko, Anatolii P.; Hermaniuk, Yuliia M.ENG: The aim of the paper is to improve approaches to the design and operation of private sidings of grain elevators for loading of unit trains. The research is based on the methods of organizing of railway operation. One of the main methods of reducing costs in the logistics chain, which provides for the export of grain cargoes is the using of unit train technology for transportation. Introduction of this technology in Ukraine is limited by the low loading capacity of elevators. In the paper the basic schemes of track development of elevator private sidings and analyzes the use of different technical means for performing shunting operations are presented. The results of the performed research can be used for designing and reconstruction of the existing elevators and for building the new ones, as well as for estimating the costs associated with different logistic schemes for grain delivery to seaports. As result the work develops a methodology and obtains a technical-operational assessment of the technical equipment and the operation technology grain elevator private sidings for loading of unit trains.Item Controlling the Speed of Rolling Cuts in Conditions of Reduction of Brake Power of Car Retarders(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Kozachenko, Dmytro M.; Bobrovskyi, Volodymyr I.; Grevtsov, Serhii V.; Berezovyi, Mykola I.ENG: Purpose. The study aims to develop the requirements for organization of the marshalling process in the conditions when the power of retarder positions is less than the nominal one. Methodology. The research is carried out using the train traffic safety theory and mathematical modelling of hump processes. Findings. The current technical standard documents regulating the operational performance of humps do not contain direct instructions on how to proceed in the event of brake power loss by car retarders, thus creating threats to the traffic safety. This problem is quite acute for the Ukrainian railways in connection with a chronic shortage of funds for the repair and renewal of technical equipment, including the humps. At the same time, a significant drop in the volume of work leads to the fact that the hump required processing capacity can be provided in case of partial failure of retarders as well. Herewith the most important task is to ensure the breaking-up safety in conditions of parametric failures of retarders. The analysis of dangerous situations, the occurrence of which is possible at humps, as well as the modelling of cut rolling, allowed establishing the connection between the value of retarder tire pressing force on the car wheels and the breaking-up modes, providing the safety of marshalling process. The paper sets the application areas of such measures as the breaking-up speed reduction, breaking-up termination, the use of additional braking by block hangers. Originality. The originality of the work lies in the fact that it first obtained the complex of dependencies that determine the performance requirements for the power of hump retarders and allow the staff to enter the appropriate limits for breaking-up modes to ensure the marshalling process safety. Practical value. The results of the research can be used to supplement the «Instruction on the maintenance of facilities of mechanized and automated humps» in order to determine the limits of breaking-up modes when detecting the reduction of retarder power below the nominal one.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 Determination of the Optimal Cars Exit Speeds from the Retarders on Sorting Humps(KTU, Lithuania, 2023) Kozachenko, Dmytro M.; Grevtsov, Serhii V.; Titova, AnastasiiaENG: Sorting humps are the main technical means providing the breaking- and making-up of freight trains on marshalling yards. Automation of sorting process by implementing microprocessor control systems is the main direction of increasing hump yard capacity, enhancement of safety in trains breaking-up, improvement of working conditions on hump yards. The purpose of theresearch is determination of the optimal cars exit speeds from the retarders on sorting humps. Its solution is significantly complicated because of the uncertainty of cars rolling resistance coefficient, wind velocity and direction, retarder control errors. The research is performed using the methods of the simulation modelling, mathematical statistics and direct optimization methods. The originality of the work is related to the solution of the problem of choosing cars exit speeds from the retarders in a stochastic formulation. The practical value of the work lies in the fact that the proposed method allows improving the quality of sorting process as a whole by improving the software of microprocessor control systems for automatic humping, rather than by increasing their technical facilities, which as a result will reduce the cost of their construction and operation.Item Development of Analytical Methods for Calculating Time Standards for Shunting Operations(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2021) Kozachenko, Dmytro M.; Verlan, Anatoliy I.; Korobiova, Ruslana G.ENG: Purpose. The article is aimed to conduct a historical analysis of the development of analytical methods for stand-ardizing the duration of shunting operations, as well as assessing their compliance with the existing operating conditions of railway transport. Methodology. The research in this article was carried out on the basis of an analysis of literary sources and methods of the theory of the organization of the operational work of railways. Findings. The standardization of the duration of shunting operations is one of the most important tasks of the theory of operational work of railways. The existing method of standardizing the duration of shunting operations developed in the first half of the 20th century and is used to this day. The performed analysis shows that the scientific principles underlying it generally correspond to the modern conditions of the railway transport. Additional research in this area can be associated with assessing the influence of the initial location of cars on the tracks on the average duration of shunting operations, taking into account the influence of length restrictions of the cars groups being moved, as well as monitoring the implementation of established norms by statistical methods. The article also shows that the values of modern time standards for shunting operations, in many cases, are set for technical means and technologies that were used in railway transport in the 50–70s of the 20th century and do not correspond to the operating conditions of real stations and sidings of industrial enterprises. Therefore, they require revision. Originality. In this paper, based on historical analysis, the process of development of methods for setting the time for shunting operations is described and the factors influencing the current value of norms are established. Practical value. The research results make it possible to identify the reasons for the discrepancy between the existing time standards for performing shunting operations and the real operating conditions of stations and sidings of industrial enterprises, as well as to establish the main elements of the methodology for standardizing the duration of shunting operations that require revision.Item Especially the Functioning of Railway Stations in the Conditions of the Organization of Transport Dangerous Goods(Дніпропетровський національний університет залізничного транспорту ім. академіка В. Лазаряна, Дніпропетровськ, 2016) Kozachenko, Dmytro M.; Zhuravel, Irenа L.; Zhuravel, Vyacheslav V.ENG: Purpose. Ensuring a sufficient level of transport safety is an important task in the context of development of railway transport as a part of international transport corridors and under increasing freight traffic volumes. The intensification of the transport process when there is the significant depreciation of fixed assets actualizes the development and implementation of methods to of improving the safety of railway transportation of dangerous goods, as well as technological and organizational measures, which are directed decrease of risks of emergency situations with its goods. Methodology. The methods of system analysis and theory of the railways operating management were used. Findings. The regulatory framework of the dangerous goods transportation by rail was characterized. The main indicators of the dangerous goods transportation under modern conditions of railway transport functioning were investigated. A detailed structure of the factors, which influence on the stations operating conditions during the transportation of dangerous goods was developed, and the measures of the stations technology improving in order to increase the traffic safety were proposed. Originality. Authors had detailed features of the functioning of the railway stations functioning under the dangerous goods transportation management. Practical value. Taking into account the factors and implementation of the proposed measures will improve the safety level of dangerous goods processing at railway stations.Item Estimation of Private Locomotives Usage Efficiency for Freight Transportation in Ukraine(Dnipro National University of Railway Transport named after Academician V. Lazaryan; Les Ulis: EDP Sciences-Web of conferences, 2019) Kozachenko, Dmytro M.; Gera, Bogdan V.; Sannytskyy, Nazar М.; Hermaniuk, Yuliia M.; Shargun, TetyanaENG: Abstract. Ukraine has undertaken the implementation of European Union Directives, which provide nondiscriminatory admission to the railway infrastructure of independent carriers. A significant number of factors considerably affect working conditions of the carriers which are independent of Ukrzaliznytsia. One of the goals while performing transportation by independent carriers is the organization of private locomotives operation and their service by engine crews. The purpose of the article is to assess technical and economic indices of private locomotives use for goods transportation. The schemes of infrastructure objects arrangement for locomotives operation and engine crews work are presented. Performed calculations show the potential possibility of independent railway carriers to fulfil transportation to seaports with the use of its private locomotive infrastructure exclusively. The estimation of economically expedient volumes of cargo transportation by private locomotives in comparison with existing pricing of Ukrzaliznytsia is carried out. The nonlinear dependence of transportation volume depending on the distance is determined, at which the total cost of cargo transportation by Ukrzaliznytsia locomotives is equal to the cost of cargo transportation by private locomotives. The results of the study allow concerned companies to evaluate the investment efficiency into the development of locomotive fleet for rail transportation.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 Improvement of the Analysis Methods of the Working Hours` Distribution of Locomotive Crews by the Types of Train Operation in Freight Traffic(Dnipro National University of Railway Transport named after Academician V. Lazaryan; Les Ulis: EDP Sciences-Web of conferences, 2019) Kozachenko, Dmytro M.; Berezovyi, Mykola I.; Malashkin, Vyacheslav V.; Bolvanovska, Tetiana V.; Grimak, YuriiENG: Abstract. The work is aimed to increase the efficiency of cargo transportation by railway transport by improving the work organization of locomotive crews. The research is based on the methods of organization of operational work of railways and the methods of mathematical statistics. The problem of increasing the use efficiency of working hours of locomotive crews in freight traffic is considered in the article. Based on the statistical data processing of drivers' routes, the working hours` distribution of locomotive crews for different types of train operation in freight traffic for four locomotive depots was performed. During the research, a conditional division of the working time of locomotive crew by the type of work was performed, if the crew worked with trains of various categories. The algorithm for assigning the idle time and empty running of locomotive to certain types of train operation was also developed. The work originality lies in the fact that it improves the methods of analysis of the working hours` distribution of locomotive crews for certain types of train operation in freight traffic. The developed methods give an opportunity to evaluate the work specifics of individual locomotive depots and provide the initial data for planning the use of locomotives and the work and rest schedule of locomotive crews.Item Improvement of the Method for Standardizing the Duration of Rail Cars Shunting(НГУ, Дніпро, 2021) Kozachenko, Dmytro M.; Gera, Bogdan V.; Manafov, E. K.; Gorbova, Aleksandra V.; Korobiova, Ruslana G.ENG: Purpose. To improve the method for calculating the time standard for shunting cars from track to track in order to take into account the local operating conditions of railway stations and railway sidings. Methodology. During the research, the methods of theory of railway operation were used. The problem of calculating the time standard for shunting operation was solved as the problem of searching the optimal division of train set into the car groups to achieve minimal time consumption for shunting operation. Findings. In the course of the study, the methods for calculating the time standards for initial and fi nal operations, as well as movements performed when shunting cars from track to track were improved. It was proved that the minimum time spent on shunting cars from track to track was achieved when the train set was divided into the minimum possible number of parts and the cars were shunted in the longest possible groups and one remaining group. It was also established that with suffi cient accuracy for engineering problems the duration of shunting train set from track to track can be represented by the piecewise linear function of the car number in it. Originality. The work originality consists in improving the method for calculating the time standard for shunting cars from track to track, that, unlike the existing one, takes into account the length limitations of the car groups being shunted from track to track, as well as the actual composition of operations performed in the process of shunting. Practical value. The use of the developed method allows setting time standards for shunting cars from track to track, taking into account the local operating conditions of railway stations and sidings of industrial enterprises. The method also makes it possible to simplify solving problems of searching the optimal order of performing more complex shunting operations, such as sorting cars into several tracks, collecting cars on one track, train formation, and others.Item Improvement of the Method of Time Rationing for Assembling Car Groups on One Track(Dnipro University of Technology, Dnipro, Ukraine, 2024) Kozachenko, Dmytro M.; Gera, Bogdan V.; Taran, Ihor; Korobiova, Ruslana H.; Malashkin, Vyacheslav V.; Hermaniuk, Yuliia M.ENG: Purpose. To improve the method for standardizing the duration of the shunting operation of assembling cars on one track. This can be achieved as a result of solving the following research problems: development of a method for searching the optimal order of assembling cars on one track; distribution parameters estimation of the random value of the duration of shunting operation of assembling cars on one track based on calculation experiments. Methodology. During the research, the methods of theory of railway operation, dynamic programming and mathematical statistics were used. Findings. Research on the assembling process of car group to one track established the distribution parameters of the random variable of time spent for shunting. In the course of the research, the problem of choosing the optimal order of shunting operations during car assembling was formalized and solved as a problem of dynamic programming. The time spent for shunting work was chosen as the optimality criterion. The paper considers the possibility of approximating the data of calculation experiments by analytical dependencies. It was found out that the use of linear polynomials with interaction allows obtaining dependencies describing time standards with a relative accuracy of ±5 %. Originality. The method is improved for developing the time standards for shunting work, which, unlike the existing one, is based on the performance of a series of calculation experiments, each of which solves the optimization problem of finding such an order of assembling cars that ensures minimum time consumption for shunting. Practical value. The methods developed in the work and the dependencies obtained allow improving the quality of decisions made when developing technology and designing railway stations and sidings of industrial enterprises.Item Improving the Efficiency of Multi-Group Trains Formation(Kaunas University of Technology; Publishing House "Technologija", 2019) Kozachenko, Dmytro M.; Bobrovskyi, Volodymyr I.; Skovron, Ihor Ya.; Jablonskyte, J.ENG: The formation of multi-group trains is one of the typical tasks solved in the process of operational work of railways. The purpose of this study is to reduce the time spent on shunting operations associated with the formation of multi-group trains. The studies are performed using the method of simulation modeling. The method of searching for a rational order of multi-group train formation was improved. It is based on the statistical evaluation of the variety of simulation modeling results of shunting movements, the sequence of which is determined using the various methods and formation schemes. The choice of the best method and the scheme of train formation makes it possible to reduce the duration of shunting by 7.1-23.3% when using a flat shunting neck and by 8-11% when using a sorting hump. The methods presented in this paper make it possible to develop software products for the automated preparation of shunting plans for the formation of multi-group trains at the stations.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 Improving Transport Logistics of Extractive Industry Products in the Context of Capacity Constraints on the Railways(Dnipro University of Technology, Dnipro, Ukraine, 2022) Aldanazarov, K.; Toktamyssova, A.; Karsybayev, Y.; Korobiova, Ruslana G.; Kozachenko, Dmytro M.ENG: Purpose. To improve the distribution methods of freight flows on the railway network under conditions of capacity constraints. Methodology. Methods of railway operation theory and operations research were used. The problem of cargo flow distribution on the railway network was solved as a multi-product (interchangeable cargoes) transport linear programming problem with capacity constraints in the network form. The average cost of freight transportation is established by the methods of probability theory. Findings. In the course of the research the methods of cargo traffic calculation on the railway network are improved. The proposed approach to the formalisation of the task makes it possible to take into account the presence of different cargoes to be transported, capacity constraints of some railway network sections, as well as non-linear nature of dependence between the volume and cost of transportation. To meet the requirement of consignors’ equal access to public carrier services, the method for calculating the cost of transportation for an individual consignor is improved. Originality. Scientific novelty of the paper consists in improvement of methods of cargo traffic distribution on the railway network and tariffing of cargo transportation services in conditions of restricted supply capacity of separate sections. Practical value. The extractive industries have a steady flow of goods. The main logistic tasks in this case are to ensure transportation of the given volume of cargo and reduce the cost of transport services. Using the proposed mathematical methods of optimization allows you to get higher-quality solutions compared to the method of technical-economic comparison of options, which provides an overall cost reduction for cargo transportation. The improved method of tariffication of transportation can reasonably allocate the savings from reducing the cost of transportation among cargo consignors and thus reduce their logistics costs.Item Increasing the Efficiency of Using Backline and Private Railway Infrastructure in the Conditions of the Transportation Market(Dnipro University of Technology, Dnipro, Ukraine, 2023) Issina, Botagoz; Kozachenko, Dmytro M.; Taran, Ihor; Muratbekova, Gulzhan; Bitileuova, ZukhraENG: Purpose. Improving the efficiency of interaction between enterprises that operate public and private railway infrastructure when performing cargo transportation and cargo operations. Methodology. The studies were carried out using the methods of the theory of railway operation and economic and mathematical modeling. Findings. The study found that the transition from a planned economy to a market economy along with increasing customer requirements for the composition and quality of transport services is an objective reason for an increase in carriage downtime at private sidings and junction stations, a shortage of track capacity and shunting locomotives. It is shown that the existing approaches to assessing the effectiveness of the interaction between train tracks of enterprises and mainline railways are aimed at improving the performance of the rolling stock and do not create incentives to solve the problem of the shortage of transfer and processing capacity of the railway infrastructure. Originality. The paper proposes an improved method for assessing the effectiveness of the interaction of participants in the transportation process when performing transportation and cargo operations on the private sidings of industrial enterprises, based on the time the infrastructure is occupied. This approach, unlike the existing one, encourages railways and industrial enterprises to jointly search for the best technological solutions for the use of public and private railway infrastructure. Practical value. The method proposed in the paper for assessing the interaction of participants in the transportation process makes it possible to separate station services in the tariff for the use of the railway infrastructure into separate services of service facilities and track access to them. This will create a competitive environment and encourage participants in the transportation process to use the existing railway infrastructure and develop a new one to obtain a synergistic effect more efficiently.Item A Method for Optimization of Time Intervals between Rolling Cuts on Sorting Humps(Springer, Heidelberg, 2018) Kozachenko, Dmytro M.; Bobrovskyi, Volodymyr I.; Demchenko, Yevhen B.ENG: Abstract Sorting humps are the main technical means providing the breaking- and making-up of freight trains. Automation of sorting process by implementing microprocessor control systems is the main direction of increasing hump yard capacity, enhancement of safety in trains breaking-up, improvement of working conditions on hump yards. However, for wider introduction of such systems at the humps, it is necessary to reduce their cost. One of the main tasks of hump control systems is the determination of the optimal cars exit speeds from the retarders. Its solution is significantly complicated because of the uncertainty of cars rolling resistance coefficient, wind velocity and direction, retarder control errors. The paper is aimed at solving the problem of searching for such cars exit speeds from the retarders that provide the longest time intervals between them at the switches. Implementation of this method will make it possible to improve the quality of sorting process as a whole by improving the software of microprocessor control systems for automatic humping, rather than by increasing their technical facilities, which as a result will reduce the cost of their construction and operation. The research results, when solving the problem of searching for cars exit speeds from the retarders, allow us to move from searching for the maximum of a nonlinear non-smooth function of two variables to solution of an equation with one variable, which significantly accelerates and simplifies the solution to the problem.Item A Model of Transit Freight Distribution on a Railway Network(The Silesian University of Technology, Katowice, Poland, 2019) Kozachenko, Dmytro M.; Skalozub, Vladyslav V.; Gera, Bogdan V.; Hermaniuk, Yuliia M.; Korobiova, Ruslana G.; Gorbova, Aleksandra V.ENG: Summary. The peculiarity of the transit freight transportation by rail in international traffic is the fact that while performing transportation, the railway administrations are in competition among themselves. At the same time, the routes of cargo traffic volumes sig- nificantly depend on the conditions of transportation by railways of individual states. The mathematical model for the distribution of transit freight traffic volumes on the railway network, based on the methods of graph theory and game theory, was proposed in this ar- ticle. The developed model enables the evaluation of the possibilities of attracting transit freight traffic volumes by indi by changing the tariff value and transportation conditions.Item Multi-Criteria Evaluation of Professional Qualities of Railway Dispatching Personnel Using Computer Simulations(Dnipro University of Technology, Dnipro, 2022) Ursarova, A.; Mussaliyeva, R.; Mussabayev, B.; Kozachenko, Dmytro M.; Vernyhora, Roman V.ENG: Purpose. Development of a formal method to evaluate professional training of operating and dispatching personnel of railway stations. Methodology. Simulation approaches to generate performance indicators of a human dispatcher under the specified operational conditions are selected as well as techniques of cluster and discriminant analysis to evaluate the obtained results. Findings human factor is one of the main factors determining the performance of technical systems in general and the efficiency of a railway transportation system in particular. Analysis of the transport accident causes demonstrates that from 63 to 95 % of them are related to some extent to a human factor. In this regard, a problem of objective assessment of dispatching staff training quality and its effect on the indices of railway transportation functioning, including the operation safety is reflected in this article. Based on investigations carried out and the results obtained the operator training simulator of railway station was developed. Originality. A simulator is improved of the railway station functioning while using deterministic finite automat formalizing the procedures. The proposed approach helps simulate processes taking place at the railway stations and resulting from the correct actions by operators as well as the incorrect ones. In addition, the paper proposes the improved method to evaluate professional training of station operators based upon the cluster and discriminant analysis providing HF impact minimization in the process of the problem solving. Practical value. The approaches have been proposed to apply while developing training equipment for station operators. On the one hand, formal methods of cluster and discriminant analysis help provide human participation in the evaluation of professional training of station operators at the stage of training sample formation to be analysed. On the other hand, they make it possible to identify the trainee affiliation with a group of the defined training level and prevent from HF impact while evaluating training results of certain applicants.Item An Optimization Method of the Multi-Group Train Formation at Flat Yards(Taylor & Francis Ltd., UK, 2021) Kozachenko, Dmytro M.; Bobrovsky, Volodymyr I.; Gera, Bogdan V.; Skovron, Ihor Ya.; Gorbova, Aleksandra V.ENG: Formation of multi-group trains is aimed at arranging their cars in a given order and is one of the mass operations performed at railway. In this regard, the reduction of the duration of shunting operations for the formation of multi-group trains is an urgent task for railway transport. In this paper, for a discrete deterministic-controlled system that simulates the operation of the flat yard, a mathematical statement of the problem of choosing the optimal order of multi-group train formation is obtained. The set of possible states of the system under study and the transitions between them are presented in the form of directed graph, which made it possible to reduce the problem of choosing the order of train formation to the problem of searching the shortest paths on the graph. An algorithm of searching the optimal order of train formation is proposed.Item Optimization of the Enterprise Railcar Fleet Structure for the Transportation of Iron Ore Raw Materials(Kaunas University of Technology, Kaunas, Lithuania, 2021) Kozachenko, Dmytro M.; Hnennyi, Oleh M.; Berezovyi, Mykola I.; Malashkin, Vyacheslav V.ENG: The paper is devoted to the transportation issues of iron ore raw materials by railway transport. The purpose of the research is determining the number of private cars a mining enterprise should have to transport its products. The research is performed using the methods of the theory of railways operation, economic and mathematical modeling, mathematical statistics and direct methods of minimization. During the research the task for determining the number of private cars of the enterprise is reduced to the stochastic problem of minimizing the modified reduced costs of the enterprise, which are represented by a piecewise nonlinear function of one variable. The originality of the work is related to the fact that it has improved the method for calculating the car fleet of enterprises by taking into account differences in the technology of loading private cars and the involved cars of operator companies. The practical value of the work lies in the fact that the proposed method allows one to reduce the logistics costs of mining enterprises due to a more accurate assessment of the costs associated with the development and operation of the car fleet, as well as the accompanying railway infrastructure of sidings.