Simulation of the process of current distribution in a traction rail network

The article synthesizes a simulation model of a section of a traction rail network, analyzes the norms of permissible asymmetry current, at which a choke-transformer is able to function with a set quality. The simulation of the current distribution process that occurs in the traction rail network during the movement of trains of increased weight and length has been carried out. The graphs of the dependence of the asymmetry current on the traction current consumed by the electric rolling stock have been obtained, and the simulation of the dynamics of changes in the traction current in each of the rail lines has been carried out when the train was moving along a section of the traction rail network. Conclusions about the need to monitor the state of traction rail network elements, the service life of which in heavy traffic conditions is significantly reduced both due to dynamic loads and due to overheating due to the passage of increased traction currents have been made.

Evaluation of dynamics of atmospheric air pollution of the city center by emissions of the road transport using cartographic method

When characterizing vehicle emissions, as a rule, the speed of traffic flows is not taken into account, which significantly reduces its accuracy. In this regard, the use of the cartographic method for assessing the speed of traffic flows on the tracks is quite reasonable and relevant. The assessment of the intra-annual dynamics of the intensity of traffic flows and emissions of the main components of exhaust gases by vehicles on the streets of the city of Ryazan and bypass roads using a cartographic method for recording the intensity of traffic flows was carried out. The study was conducted in 2018–2019 on the territory of Ryazan. The material used for the study was cartographic data published in free access on the website www.yandex.ru traffic jams. The length of traffic flows with a speed of 5-10 km / h (heavy traffic conditions – TTU) was determined at different times of the day on days of the week. The indicators of the average hourly length of heavy transport conditions were calculated. Bypass roads of the city were characterized by a significantly greater length of sections with TTU compared to the city streets from Tuesday to Thursday and Sunday (p<0.05). The increased complication of traffic conditions during morning and evening rush hours led to an average annual increase in emissions of the main components of vehicle exhaust gases of 17.7% and 14.9% respectively, with the largest increase in emissions being typical for the city center. At the same time, the maximum complication of transport conditions on the bypass roads was observed in the summer and spring (from Monday to Wednesday and Sunday), while on city highways - on working days in the autumn and weekends in winter. On the city streets, the greatest length of heavy traffic conditions during the morning rush hour was observed in winter, and the shortest was in summer, while the evening rush hour, on the contrary, was most pronounced in autumn. On the bypass roads, there was a clear tendency towards heavier transport conditions over a longer period of the day according to the scheme winter–autumn–spring– summer.

On the Estimation in Multi-server Multi-Core Open Queuing Networks

The paper is devoted to the analysis of queueing systems in the context of the network and communications theory. We investigate the estimation in a multi-server multi-core open queueing networks and its applications to the theorems in heavy traffic conditions (fluid approximation, functional limit theorem, and law of the iterated logarithm) for a queue of jobs in a multi-server multi-core open queueing networks..