Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan

About: Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan is a education organization based out in Dnipro, Ukraine. It is known for research contribution in the topics: Track (rail transport) & Bogie. The organization has 736 authors who have published 655 publications receiving 1468 citations. The organization is also known as: Institute of Railway Transport Engineers.

Asymmetric power supply circuit design for electric rolling stock on the electrified DC rail

Abstract: Modern requirements for the traction power supply system of direct current in providing the high-speed movement are reduced to the need of ensuring a normalized voltage level of 2900 V on current collectors of electric locomotives. At the same time, the power supply system has to be stable on changes in power consumption and have the necessary specific energy intensity. The purpose of the work is to explain the transition to a new circuit design of the traction network using additional generators of electric energy. The proposed asymmetrical power supply system of the electric rolling stock allows to provide the required voltage level on the electric locomotive current collectors, to reduce the range of its changes and to reduce the power losses by 14.3% compared to the symmetrical centralized power supply circuit design with passive boosting of the traction network.

Identifying threats in computer network based on multilayer neural network

Abstract: Purpose. Currently, there appear more often the reports of penetration into computer networks and attacks on the Web-server. Attacks are divided into the following categories: DoS, U2R, R2L, Probe. The purpose of the article is to identify threats in a computer network based on network traffic parameters using neural network technology, which will protect the server. Methodology. The detection of such threats as Back, Buffer_overflow, Quess_password, Ipsweep, Neptune in the computer network is implemented on the basis of analysis and processing of data on the parameters of network connections that use the TCP/IP protocol stack using the 19-1-25-5 neural network configuration in the Fann Explorer program. When simulating the operation of the neural network, a training (430 examples), a testing (200 examples) and a control sample (25 examples) were used, based on an open KDDCUP-99 database of 500000 connection records. Findings. The neural network created on the control sample determined an error of 0.322. It is determined that the configuration network 19-1-25-5 copes well with such attacks as Back, Buffer_overflow and Ipsweep. To detect the attacks of Quess_password and Neptune, the task of 19 network traffic parameters is not enough. Originality. We obtained dependencies of the neural network training time (number of epochs) on the number of neurons in the hidden layer (from 10 to 55) and the number of hidden layers (from 1 to 4). When the number of neurons in the hidden layer increases, the neural network by Batch algorithm is trained almost three times faster than the neural network by Resilient algorithm. When the number of hidden layers increases, the neural network by Resilient algorithm is trained almost twice as fast as that by Incremental algorithm. Practical value . Based on the network traffic parameters, the use of 19-1-25-5 configuration neural network will allow to detect in real time the computer network threats Back, Buffer_overflow, Quess_password, Ipsweep, Neptune and to perform appropriate monitoring.

Economic and mathematical justification of train traffic volume distribution on the direction of rail transportation with parallel runnings Znamenka – Odessa

Abstract: Purpose. Determination of the economic grounded sizes of motion of freight trains between the areas of railway direction with parallel runnings. A research task is distribution in the operative terms of train work at admission of freight trains between the areas of railway direction with parallel runnings. Methodology. Research is executed with the use of classic methods and methods of the linear programming. Findings. The rational train traffic volume distribution on a railway infrastructure with parallel runnings is presently carried out by an expert method on the basis of information about the before executed volumes of transportations without application of feasibility study. For the task solution of train traffic volume distribution between parallel runnings of railway direction a linear model and methods of the linear programming are used in operative terms. At a design all train traffic volume on a direction part on undistributed train traffic volume – which remaines unchanging for all variants of operative management and distributed – which it is possible to redistribute in some limits between parallel runnings of railway direction. Originality. From the scientific point of view the work is interesting and important by the methods of the linear programming, which allow conducting train traffic volume distribution between parallel runnings in operative terms. Practical value. The practical value of this research is in applying of the described economic and mathematical modeling methods of train traffic volume distribution between parallel runnings on direction Znamenka - Odessa. 10 pairs transmission of freight trains from basic direction Pomoshnaya – Kolosovka – Odessa on parallel direction Pomoshnaya - Kotovsk – Separate is Odessa can be included with the optimum variant.

Development of passenger traffic service quality management system of railway enterprises

Abstract: Purpose. At the present stage of development of Ukraine’s economy, passenger traffic service quality management of railway enterprises became one of the main tasks to ensure their efficient operation. In terms of railway re-forms and increased competition in the transport market, the discrepancies between the technological level of traffic and the growing needs of society and the quality standards of transport services, the priority is the establishment of quality management system for passenger traffic services in rail transport. This question should be considered in the paper. Methodology. To achieve this goal and ensure a high quality level of passenger traffic services in rail trans-port, which involves a combination of approaches to the position of consumers (determination of their satisfaction) and railway enterprises (measurement of results and formation processes of service quality), the paper proposed a passenger traffic service quality management system. The proposed methodical approach to formation of the passenger traffic service quality management system in rail transport implements a principally new scheme of interaction of elements during provision of services, where the inter-related resources (human, material, financial, information), means, instruments and processes result in creation of quality transport service. Findings. The efficiency of the passenger traffic service quality management system allows detecting the dynamic of improvement of the services provided by the railway enterprises and building the system which is self-learning on the principles of continuous improvement. The paper grounded new principles of the passenger traffic quality management, which were formed on the basis of general management principles, quality management principles and railway transport management principles. Originality. The work presents the developed passenger traffic service quality management system targeted to meet the expectations of passengers from transport process while taking into account the economic interests of railway enterprises. The basis of this system is conceptual principles, namely, goal, objectives, subject, object, principles, functions and practical recommendations, which generally determine the relationship of the basic elements of the passenger traffic service quality management in rail transport. Practical value. The practical value of the obtained by the author results is that their implementation will enable railway enterprises to forecast the improvement of service quality level, taking into account their specific features and create solutions for control and regulation of processes and passenger traffic service quality effects. The theoretical and methodological provisions may be used in the formation, operation and improvement of the quality management system for passenger traffic services in rail transport.

Modeling of development vertical deformation of railway track

Abstract: Purpose. State of railway track must meet the conditions of safety, comfort and smooth ride. The presence of irregularities deteriorates the dynamics of interaction of track and rolling stock, causes speed limiting, creates the possibility of movement safety violation. This brings up the question concerning the study of the factors leading to the possibility of track irregularities and the process of their development. The purpose of this paper is to analyse the processes of emergence and development of irregularities in the area of unequal vertical elasticity of railway track using mathematical modelling. Methodology. Railroad under the trains works as the system of elastic bodies, so the emergence and development of irregularities can be represented as the transition from elastic to permanent strain. Irregularity development will affect the dynamics of interaction between track and rolling stock not only at the wheel location directly in the area of irregularity, but also at a certain distance beyond. Therefore, to study the development of irregularities, including those along the track, it is necessary to model the process of wheel load movement along the area. The adopted model consists of a wheel set moving on inertia-free beam and resting on individual supports. It is described by Lagrange differential equations. The work introduced the hypothesis that the level of permanent strain is distributed in proportion to the dynamic deflection derivative. Findings. Location of vertical longwise irregularity does not necessarily reproduce the location of the problem area. While in operation the vertical irregularity extends not only in depth but also along the track, herewith the increase in length is accompanied by the displacement of local maxima and the emergence of new ones. This leads to the development of so-called «pits» when approaching unequal-elastic areas. Originality. The work provides further development of tasks for track and rolling stock interaction modelling, in particular aimed to take into account the unequal elasticity areas and their influence on the formation of the track irregularities. The paper proposes new approaches to modelling the transition from elastic to permanent strain that allows predicting the development of track irregularity sizes depending on the area characteristics. Practical value. The results obtained by the author can be used to determine the schedule for track equal elasticity renovation works, as well as to analyse the measures aimed at the prevention of irregularities in areas with variable elasticity of railway track.