No 2 (2025)

The degradation of permafrost soils in the Yamalo-Nenets Autonomous District (YNAO) shows a negative trend of increasing, which is associated with both climate change and human engineering and economic activities. The article examines the issue of the occurrence of ground subsidence in the foundation of linear transport infrastructure in the Arctic zone of the Russian Federation from the perspective of establishing a relationship between cryogenic deformations and soil characteristics. A geotechnical model of the "embankment – foundation" system has been developed for conditions of permafrost degradation in the YNAO, enabling the design of measures to improve operational reliability through soil thermal stabilization or anti-deformation structures. To confirm the feasibility of calculations based on the developed geotechnical model, its verification was carried out by comparing qualitative and quantitative deformation patterns with the results of engineering-geocryological monitoring of an operational section of the Nadym – Salekhard highway.

It is shown that under the action of an external electric field in a single-mode fiber optic light guide the Kerr effect appears, and under the influence of a magnetic field – the Faraday effect. In this case there is a change in the ellipticity of polarized radiation and rotation of the large axis of the ellipse. The change in the specified parameters of polarized radiation leads to an increase in polarization mode dispersion. An estimate of the total pulse broadening due to the effect of the electromagnetic field is made. The paper states that such pulse broadening together with pulse broadening due to chromatic dispersion causes a significant limitation of the length of the regeneration section and a decrease in the throughput of fiber optic light guides.

Currently, one of the tasks of anti-terrorist security is to eliminate the uncontrolled passage of vehicles to the territory of the educational organization. To solve this problem, a software system for automating the control and management of vehicle access is proposed, taking into account the specifics of educational institutions based on the recognition of vehicle licence plates. The article considers a generalized scheme for transport access control and management, the architecture of the software system with a detailed description of the modules, as well as its limitations and advantages over other systems of a similar purpose. The fragments of screen forms of the developed software system are presented. The software system allows to calculate the violators of the access regime, to monitor the presence of vehicles on the territory of the educational organization, and eliminate the human factor in the work of a security guards. This system can be recommended for security chiefs, security guards to ensure security on the territory of the educational organization. At the same time, it can be included in the general access control and management system or act independently.

Robotic process automation systems are widely used in the tasks of a number of modern computing centers. The Russian robotic process automation platform “RPA Robin” has proven itself well, including in the field of automation of administration of a whole class of railway transport information systems. The emerging growth in the number of information systems managed and administered by software robots imposes limitations on the RAM resource of terminal servers. This paper proposes a way to reduce RAM consumption by terminal servers of software robotics in computing centers by applying a new specialized method of lossy image compression.

The question of the applicability of the Dijkstra algorithm, A* and Breadth-first search for solving pathfinding problems in environments with obstacles is considered. These algorithms can be used to solve problems of spatial development of linear objects of land transport infrastructure.

A series of simple experiments were conducted with the algorithms in order to quantify their asymptotic complexity, i.e. the number of operations performed and the execution time of the algorithm in conditions of pathfinding in environments with obstacles. The series of experiments has a different configuration, determined by the direction of the search (unidirectional and bidirectional) and the method of cell passage (direct and mixed) and a variant of the search algorithm. When considering the A* algorithm, various metrics such as Chebyshev, Manhattan, and Euclidean distances were used as an additional parameter configuring the algorithm's operation.

The mechanical characteristics of an antifriction polymer composite coating based on fabric with PTFE fiber are studied. The fabric of polymer fibers is impregnated and glued to the substrate (base) with a heat-resistant matrix binder of cold curing based on phenylone with modifiers introduced into the matrix (fine copper powder and oil). The mechanical properties of the coatings were obtained by microindentation using the NanoTest 600 analysis system from Micro materials Ltd. The mechanical characteristics of the experimental samples were determined: microhardness, elastic modulus, as well as their viscoelastic properties. It is shown that the use of the instrumental indentation method can be successfully applied to assess the mechanical characteristics of the considered type of coatings. A technique for obtaining a creep curve for assessing the viscoelastic characteristics of the coating using the continuous indentation method is proposed. The optimal composition of modifiers providing the highest hardness and elastic modulus of the composite is determined.

The loss coefficients of vibrational energy play an important role in the analysis of vibroacoustic characteristics occurring in overhead cranes. These coefficients allow us to estimate the rate of vibration attenuation in various structural elements, which, in turn, affects the durability and reliability of the equipment.

Using a dynamometer hammer to excite vibrations is standard practice, as this method allows precise control of the amplitude and frequency of the excited vibrations. Recording the attenuation process at nine octave frequencies provides detailed data on the dynamic characteristics of the system.

Mathematical processing of experimental data makes it possible to identify patterns and establish regression dependencies for various structural elements, such as wheels, wheelset axles, and load-bearing frames. These dependencies can be used to more accurately model the behavior of the system under various operating conditions.

Thus, the regression dependences obtained are an important tool for engineers in the design of overhead cranes, allowing them to optimize their design, taking into account vibration characteristics and minimizing noise.

Cylindrical gears with arc teeth make it possible to multiply the durability in terms of the contact and bending strength of gears of power drives of energy-intensive machines operating under conditions of inevitable skew angle of axes. Gears with arc teeth have the property of compensation of the skew angle by axial displacement (self-adjustment) of one of the wheels while ensuring the absence of edge contact of teeth in engagement. In the work an approximate dependence for calculation of displacement value of the touch point (error not more than 1...5 %) of the arc teeth in engagement on the active surface of the arc tooth of the gear in the direction of the axis of its rotation is offered. For the traction cylindrical gear of an electric locomotive with a different degree of localisation of the contact of the arc teeth, the analysis of the value of the self-alignment of the wheel with arc teeth, compensating for the skew (0, 1′, 2′, ...,7′) of the teeth in engagement, as well as the value of the displacement of the half-wheels in order to obtain an adaptive cylindrical gear with arch teeth of two contact zones in engagement.

The article discusses the problems of high consumption of electricity from the traction network by modern domestic AC electric locomotives with collector drive and low power quality on their pantographs. It was found out that these problems are caused by the presence of reactive power in the contact network, consumed by electric locomotives in almost equal proportions with the active one, and significant distortions of voltage and current. A new method for controlling the arms of rectifier-inverter converters based on IGBT transistors is proposed, which makes it possible to increase the power factor of a modern domestic AC electric locomotive with a collector drive to 0.99 and reduce the coefficients of the harmonic components of voltage and current on its current collector to 4 % and 10 %, respectively. The proposed method will significantly improve the efficiency of driving trains using the "Virtual Coupling" technology.

A functional scheme of the automatic control system for the pneumatic brake of a freight train with the possibility of identifying the actual braking parameters of the train and the resistance to movement is proposed, which along with other means of automatic train control ensures the safety of transportation on railway transport. The extended Kalman–EKF filter was used as an algorithm for identifying the braking parameters of the train, as well as the resistance to movement. The results of modeling with the use of algorithm EKF and without it are presented. The advantage of using the proposed system in terms of ensuring high-quality control by increasing the intervals between braking on a “harmful” descent is shown, which contributes to increase of section speed of movement, as well as sufficiently accurate implementation of the algorithm of target braking.

The power plant capacity of a diesel locomotive is one of the main factors determining its operational efficiency. As shown by the analysis of data from diagnostic subsystems of 27 sections of 2TE116U series diesel locomotives and 17 TEP70BS series diesel locomotives, up to 80 % of locomotives are operated with a power plant capacity reduced by 5...25

%, which leads to an increase of 2...5 % in fuel consumption for traction operation of the locomotive. As a result of the analysis of the diesel parameter values, it was found that the main reason for the decrease in power is a violation of the adjustment of the lever gear of the fuel pump rack drive under normal technical condition of the fuel equipment and the diesel air supply system. In this case, the normal power level of the power plant can be restored by a microprocessor control system for correcting the setpoint of the position of the power shaft of the actuator of the electronic diesel regulator with simultaneous control of the exhaust gas temperature across the cylinders. It is shown that an additional reduction in fuel consumption for train traction can be achieved by equalizing the loads on the diesel cylinders.

The article is devoted to modeling the interaction of service quality indicators and key performance indicators (KPIs) within the framework of a Single Network Technological Process (ESTP) of freight rail transportation. The authors consider a systematic approach to the management of a transport holding company, focusing on eliminating contradictions between functional divisions units and increasing customer satisfaction. To analyze the identified "gaps", the Zeithaml Gap model is used, which allows assessing discrepancies between consumer expectations and the actual quality of services. The article suggests solutions to minimize these gaps, including the optimization of the ESTP, the introduction of digital technologies and the modernization of infrastructure. Special attention is paid to the integration of the holding's strategic goals with operational KPIs, which contributes to increasing economic sustainability and competitiveness. The results of the study can be useful for transport companies seeking to improve the quality of service and management efficiency.

The article presents an analysis of a mathematical nonlinear model of following a leader vehicle in a traffic flow for the purpose of rational organization of traffic on the city road network. Based on classical micromodels of the follow-the-leader theory, the authors propose mathematical expressions for calculating accelerations, speeds, and distances for a follower vehicle in a traffic flow, taking into account the time shift associated with the driver's reaction time. Graphs of the dependences of these parameters on the time of vehicle movement are obtained. A mathematical dependence is proposed that establishes a connection between the accelerations of the leader and follower vehicles in the analyzed traffic pattern.

In the context of dynamic economic and geopolitical changes, it is important to provide adaptation mechanisms that allow for rapid modification of nodal transport and technological processes in accordance with current requirements and circumstances. Preliminary and subsequent software assessment of the parameters of nodal infrastructural and technological interaction at all stages of layout solutions allows us to draw conclusions about the principles of formation of zones and facilities, the correspondence of transport modes and points of nodal interaction, as well as their locations. For these purposes, a comparative analysis of the hub zone indicators was carried out depending on the degree of their impact on the node/ hub structure according to the criteria of decision theory, cluster analysis methods that allow evaluating objects within one zone (cluster) and identifying hidden structures in a data set, determining groups of objects, their similarities and differences. A software package for selecting rational parameters of objects in layout solutions for a transport hub was developed according to the author's modification of a traditional genetic algorithm (GA) into a genetic layout algorithm for a transport hub (GLA TU), taking into account random selection, fuzzy sets of parameters, combinatorics and variation of big data arrays using analogies of natural selection.

Research aimed at selecting and evaluating potential locations for transport and logistics facilities is of paramount importance in the context of the active development of the transport and logistics complex in the Far East. Today, the modernization of the transport infrastructure is actively underway, port facilities and cross-border crossings are being strengthened, so new approaches need to be developed to select locations for transport and logistics centers. The aim of the work is to develop a method for factor-analytical assessment of locations of transport and logistics facilities, as well as its testing at the regional level. The objectives of the research include the analysis of existing methods for choosing the location of a transport and logistics facility, a description of the factors influencing the choice of location and the formation of a factor-analytical assessment method. Theoretical and empirical research methods were used. The article considers additional factors influencing the choice of an object's location, and describes in detail the stages of assessing the locations of transport and logistics facilities.