To address the issue of reduced comfort resulting from rapid aerodynamic pressure changes inside the tunnels used for urban rapid transit trains, a study was conducted on the effects of the tunnel diameter and pressurerelief schemes on incar pressure. First, pressure comfort standards were selected based on relevant regulations, and a finite element model was established, which included a train model, a tunnel model, and pressure relief measures at the tunnel entrance. Subsequently, the pressure variations inside and outside of a train were investigated for different tunnel diameters and airtightness indices. Finally, the impact of implementing buffering schemes at the tunnel entrance on the incar pressure was analyzed. The research results indicated that when the tunnel diameter increased from 6.0 m to 6.1 m, the maximum incar pressure variation decreased by approximately 4.2%, with further increases in tunnel diameter having a limited effect on reducing the pressure variation. When the airtightness index was ≤6 s, each additional second resulted in a 15–25% reduction in the maximum incar pressure variation. Additionally, when a fully enclosed sound barrier was installed at the tunnel entrance as a pressurerelief structure, the maximum incar pressure variation could be reduced by approximately 4050%. Measures can be taken to enhance the overall vehicle airtightness, such as improving the seals around the doors for the driver's cab and passenger cars, installing pressure protection valves at freshair inlets and exhaust outlets, and enhancing the seals on the vehicle body and intercarriage passageways.

To address the problems of dynamic failure and different services in the reliability analysis of an LTEM (Long Term Evolution for Machines) trainground radio communication system, this study evaluated the reliability of an LTEM trainground radio communication system based on a dynamic Bayesian network (DBN). First, the reliability block diagram, which was constructed by analyzing the LTEM system structure and function, was transformed into a DBN, and the DBN structure and parameter modeling were conducted. Subsequently, the reliability of the LTEM system was obtained and compared based on the forward inference of the DBN. Finally, based on the backward inference of the DBN, the weaknesses of the LTEM system were recognized as a reference for operation and maintenance. The results indicate that while the LTEM system is highly reliable, the building baseband unit and train access unit are vulnerabilities that require attention.

This study aims to enhance the safety management capabilities of urban rail transit operators by designing and implementing an intelligent safety management platform, which has been validated in practice on Urumqi Metro Line 1. Centered around a dual prevention mechanism, the platform integrates 10 functional modules to achieve risk prediction and early warning, comprehensive safety assessment, safety supervision and inspection, as well as emergency decisionmaking support and resource sharing. The analysis results are presented on the platform interface in a visually graphic format, thereby increasing the efficiency of safety production management. The findings of this research can serve as a reference for the digital transformation of safety management in other urban rail transit enterprises.

Airport rail transit lines serve large airports and differ from ordinary urban rail transit lines in terms of functional role, passenger service, passenger flow characteristics, and service standards. Transport service standards for this type of particular transit line need to be improved. To meet the rapid distribution needs of airport passenger flow and enhance the quality of airport passenger services, designing specific service standards is essential. First, the particularity of the special line is analyzed from the perspectives of service passengers, technical conditions, passengers' travel needs, etc. Second, the existing service standards for rail transit are examined, and the necessity of establishing transport service standards for these special lines is elaborated. Finally, suggestions for designing service standards from the aspects of design principles, standard framework, and key contents of services are provided. This study aims to provide a reference for formulating service standards for special rail transit airport lines.

In recent years, with the comprehensive transformation and upgrading of the national economy, Beijing's urban development model has shifted towards a more scientific, sustainable, and highquality approach. The relationship between rail transit and urban development has been reevaluated, leading to the emergence of the "urban followtrack construction" planning concept. This study examines the current issues in Beijing's rail transit system, summarizes the experiences of integrating and developing rail transit station cities, reviews recent policy guidelines related to stationcity integration in Beijing, and offers new insights and perspectives on the station planning concept for rail transit lines. In terms of urban rail transit network planning, the focus is on selecting appropriate corridors and nodes to enhance interaction with urban planning. For route planning, attention is given to resource matching between stations and surrounding land, aiming to balance the planning and construction processes for mutual benefit. By integrating the lessons learned from actual engineering projects, this new planning concept is applied to practical engineering, providing a reference for the integrated development of Beijing's rail transit station cities.

Intercity railways in the GuangdongHong KongMacao Greater Bay Area (GBA) face operational challenges when used for public transit. These challenges include unclear functional specialization, misalignment with urban development plans, and insufficient network operation, leading to low service efficiency. This study proposes a reorganization strategy informed by successful regional rail transit practices globally. The strategy focuses on three key areas: (1) Reorganizing intercity railways, urban express lines, and other rail lines based on distinct functional levels for optimized service allocation. (2) Optimizing the network layout based on urban travel demand characteristics. This includes optimizing external corridors, strengthening fast and direct connections within the core area, and further strengthening urban rail interconnection through station wiring and connecting lines. (3) Optimizing intercity station and transfer services to improve passenger experience. Implementing these strategies is expected to provide valuable insights for improving operational service levels and promoting the sustainable development of intercity railways in the GBA.

To address the challenge of effectively managing APT in urban rail transit scenarios, this paper proposes a method that combines attack source graphs with deep traffic learning. This integrated approach merges attack reconstruction with traffic monitoring to facilitate identifying and detecting APT attacks. Experimental results demonstrate that this model can effectively trace the sources of APT attacks. Compared to traditional APT attack detection models based on sandboxes or abnormal characteristics, this combined model significantly improves detection accuracy, precision, recall rate, and other performance indicators.

This study focuses on a straightline section of a subway line to analyze the factors influencing the vibration source strength in subway tunnels. Vehicleinduced vibration signals and velocity signals were collected synchronously, and the timedomain and frequencydomain characteristics of allday test samples were statistically analyzed. The results showed that during peak hours in the morning and evening, the vibration response inside the tunnel may not be completely maximized, and the degree of dispersion of the vibration source intensity is directly related to the vehicle state. The study found an average difference of 6.7 dB in the VLZ of the tunnel wall measurement points caused by V₁ and V2 vehicles. Using more than 40 sets of test samples to calculate the vibration source intensity yielded results closer to the daily sample mean. The main frequency of tunnel vibration caused by the wheelrail system shifts with changes in vehicle speed. A strong linear positive correlation was observed between vehicle speed and the vibration acceleration levels of the track bed and tunnel wall. Specifically, for every 10 km/h increase in vehicle speed, the vibration increases by about 1.7 dB and 2.6 dB, respectively. When the speed difference is within 10 km/h, the vibration source intensity changes within 1 dB; when the speed difference is between 10~20 km/h, the increase is about 1.5~2.2 dB. The coefficient of speedcorrected CV was calculated to be 18.5, aligning closely with the coefficient used for train speed correction in the vibration prediction formula. Tunnel wall vibration was more discrete in the lowfrequency band below 40 Hz, but this band contributed minimally to the source strength of vibration, accounting for 15.29%. The dominant frequency band was 5063 Hz, contributing 59.55% to the source strength of vibration. These research findings can provide a reference for further refining the vibration prediction formula and offer a theoretical basis for improving the accuracy of metro tunnel source strength test results.

To investigate the sources and distribution patterns of PM2.5, PM10, and total suspended particulates (TSP) in subway stations, this study conducted particulate matter concentration tests at 11 stations along two subway lines in a city. The test areas included outdoor locations, station public areas, equipment management rooms, and corridors inside the platform end doors. The concentrations of PM2.5, PM10, and TSP in each area were measured, and elemental analysis of the outdoor and platform particulates was performed. Subsequently, the distribution patterns of PM2.5, PM10, and TSP in various areas at different outdoor concentrations were analyzed. Based on the test results, suggestions for subway particulate matter prevention and control measures were proposed. The research revealed a significant increase in iron content in particulate matter within stations compared to outdoor areas. Particulate matter containing iron in subway stations often exhibits irregular sheetlike shapes, differing from those found outdoors, indicating that railwheel friction is the source of these particulates. When outdoor particulate matter concentration levels were low, the distribution patterns of particles of various sizes were similar, generally exhibiting higher concentrations in the tunnels than in the stations and outdoors. However, when outdoor particulate matter concentration levels were high, PM2.5 and PM10 concentrations were higher in tunnels than in outdoor areas and stations. Regardless of outdoor particulate matter concentration, TSP concentrations in public areas and carriages were consistently higher than outdoors. These findings provide valuable insights for developing effective particulate matter prevention and control measures in subway systems.

The concept of speed efficiency was proposed to measure the travel speed efficiency of urban rail transit lines. This study analyzed the operating data of 170 urban rail transit lines in China, including fully closedoperated subway, light rail, and monorail systems, considering only the train operating mode at station stops. The analysis covered various factors such as average station spacing, line design speed, and travel speed. The results showed that most lines (approximately 64%) have a design speed of 80 km/h, with average station spacing ranging from 1.0 to 2.5 km. Among these lines, about 90% have a travel speed between 30 and 40 km/h, with speed efficiency distributed between 37.5% and 50.0%. Additionally, the study quantitatively analyzed the relationships between travel speed, average station spacing, and design speed, finding both positive and negative correlations. Finally, based on fitted travel speed and speed efficiency formulas and actual data, the corresponding distribution relationships of average station spacing, design speed, travel speed, and speed efficiency were calculated. These findings provide a reference for determining a reasonable travel speed range and speed efficiency for urban rail transit lines.