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In the operation of urban rail transits, train delays occur frequently, and emergency management is one of the key factors to ensure the service quality. For speed limit scenarios with high demand, this paper takes the train running in the restricted manual (RM) mode in the speed limit zone as an example and discusses a coping method by jointing train rescheduling and passenger flow control. With the goal of maximizing the number of passengers served and minimizing total train delay, a nonlinear optimization model is constructed by taking the train operation-related requirements and passenger flow control-related indicators as constraints, and the model is reformulated to a mixed-integer programming (MIP) model with quadratic constraints, which can be solved by the Gurobi solver. In order to obtain effective solutions faster, a two-stage approach is discussed, which first obtains a rescheduling timetable and then dynamically adjusts the requirement of boarding equalization to obtain the passenger flow control scheme. The validity of the model and the solution approach are discussed with the help of numerical experiments. The results suggest that the model and solution approach are feasible. When the number of trains is fixed, the reasonable implementation of passenger flow control will help to increase the number of passengers served, and the pursuit of a higher equalization of boarding is not conducive to the number of passengers served and the full utilization of transport capacity. The two-stage approach has certain advantages over the direct computing method. The methods in this paper have a guiding value for emergency decision-making in similar delay scenarios., Author(s): Jianjun Yuan [1,2]; Xiaoqun Zhao [2]; Pengzi Chu (corresponding author) [3] 1. Introduction Urban rail transits (URTs) focus on providing safe and reliable services for citizens to travel. However, [...]

It is well recognized that the flexibility of state machine design brings developers high efficiency and convenience, but it also introduces three typical problems: the output errors caused by the state logic and timing dependence, the huge load of computing caused by the historical data caching, and the uncontrollable outputs caused by the close-coupling between states. The problems still exist in software detail design and coding. Without changing state machines' functionalities and following principles of constraint conditions, the paper carries out an equivalent transformation of state machine from both time-complexity and cyclomatic complexity dimensions. The transformation forms a general process of optimization, involves merging or splitting the original state and decision condition, recombining the split or merged state according to the metamodel definition, and adding the transition condition. An optimization algorithm is proposed for three typical problems, the algorithm is used to test the state machine before and after optimization, and the feasibility of the algorithm is verified from the time-complexity and cyclomatic complexity. The practical meaning of the study is that it provides an applicable method for software detail design and refactoring especially in the area of real-time control systems or safety critical systems. [ABSTRACT FROM AUTHOR]

Aiming at young drivers' hazard perception (HP) and eye movement, a cross-sectional study was conducted in the city of Xi'an, China. 46 participants were recruited, and 35 traffic scenes were used to test drivers' hazard perception and eye movement. The difference analysis and correlation analysis were carried out for the acquired data. The results suggest that some indices of hazard perception and eye movement are significantly correlated. A higher saccade speed is in the direction of higher hazardous scenes. Higher complex scenes result in smaller saccade angle. The number of hazards unidentified is negatively influenced by complexity degree and hazardous degree of traffic scenes, and similar associations are found between hazard identification time, complexity degree, and hazardous degree. The hazard identification time and the number of hazards slowly identified are positively affected by the number of fixations and the number of saccades. Meanwhile, differences in the hazardous degree evaluation, hazard identification time, number of hazards unidentified, number of fixations, and number of saccades are found in different types of traffic scenes. The results help us to improve the design of road and vehicle devices, as well as the assessment and enhancement of young drivers' hazard perception skills., Author(s): Jingshuai Yang [1]; Chengxin Liu [1]; Pengzi Chu (corresponding author) [1,2]; Xinqi Wen [1]; Yangyang Zhang [1] 1. Introduction Young drivers are getting a lot of attention because they [...]

Auxiliary stopping area (ASA) is the necessary emergency facility for train safety of the normal high-speed maglev. The study addresses the ASA layout problem of the high-speed maglev operated bidirectionally on single track. First, an optimization model of the ASA layout for unidirectional double-track lines considering train safety, operation efficiency, and construction cost is established, and two basic methods of the ASA layout are investigated based on the distance demand characteristic of ASAs. Then, the ASA layout problem of bidirectional single-track lines is analyzed, and an ASA two-way coordination layout algorithm (ASA-TWCLA) is proposed. Finally, a numerical experiment is carried out. The results suggest that under the premise of train safety and operation efficiency, compared with using the basic methods separately on the two directions, adopting the ASA-TWCLA algorithm can obtain a more economical ASA layout scheme for the same scenario., Author(s): Yi Yu [1]; Pengzi Chu (corresponding author) [1,2]; Danyang Dong [1]; Xi Jiang [3]; Huahua Zhao [1]; Hui Lin [1] 1. Introduction With the advantages of strong climbing ability, [...]

The cross-line operation mode, based on interoperability technology, is becoming increasingly common in urban rail transits (URTs). Compared to trains running on a single line, cross-line trains can greatly facilitate transfer passengers. Taking the scenario of emergent large transfer passenger flow as an example, this paper explores the train rescheduling problem for serving transfer passengers by adding a cross-line backup train. To maximize the number of transfer passengers served by the cross-line backup train, a nonlinear optimization model is constructed by taking into account the operation parameters of planned trains on relevant lines, the deviation degree of the planned timetable, the utilization of the cross-line backup train, and the passenger flow calculation as constraints, and some linearization lemmas are proposed to transform it into a mixed integer programming (MIP) model with quadratic terms. A case study is conducted to discuss the impact of parameter changes on the objective function value and the applicability of different solution approaches. The results suggest that the operation trajectory of the cross-line backup train has an effect on the objective function value, which is related to the demand, the deviation tolerance of the planned timetable, and the running efficiency tolerance of the cross-line backup train. The corresponding methods help guide the organization of the cross-line backup train for large transfer passenger flow scenarios. [ABSTRACT FROM AUTHOR]

This study aims to analyze the effect of high-altitude environment on drivers' mental workload (MW), situation awareness (SA), and driving behaviour (DB), and to explore the relationship among those driving performances. Based on a survey, the data of 356 lowlanders engaging in driving activities at Tibetan Plateau (high-altitude group) and 341 lowlanders engaging in driving activities at low altitudes (low-altitude group) were compared and analyzed. The results suggest that the differences between the two groups are noteworthy. Mental workload of high-altitude group is significantly higher than that of low-altitude group, and their situation awareness is lower significantly. The possibility of risky driving behaviours for high-altitude group, especially aggressive violations, is higher. For the high-altitude group, the increase of mental workload can lead to an increase on aggressive violations, and the situation understanding plays a full mediating effect between mental workload and aggressive violations. Measures aiming at the improvement of situation awareness and the reduction of mental workload can effectively reduce the driving risk from high-altitude environment for lowlanders., 1. Introduction Road traffic injury is now the leading cause of death, particularly for persons aged 5-29 years [1]. Road safety is an important public health concern around the world, [...]

Young drivers are more likely to be involved in traffic accidents. The study aims to explore mechanisms behind distracted driving behaviour, traffic safety environment, driving responsibility, and hazard perception. A conceptual model is proposed based on Stimulus-Organism-Response (S-O-R) theory. The self-reported data from 367 drivers are used to estimate and modify the model based on exploratory factor analysis, structural equation modelling, and bias-corrected bootstrap method. The regression relationships and the mediators have been identified. The traffic safety environment including the traffic enforcement and the driving condition isn't related to the distracted driving behaviour. The traffic enforcement is associated the driving responsibility, the relationships between the driving responsibility, the hazard perception and the driving condition are significant, and the relationships between the distracted driving behaviour, the driving responsibility and the hazard perception are noteworthy. A positive traffic safety environment is beneficial to the safety of young drivers. The sense of driving responsibility and the self-cognition of hazard perception need attention for the early intervention of young drivers' distracted driving behaviours. [ABSTRACT FROM AUTHOR]

Auxiliary stopping area (ASA) is the key guarantee for high-speed maglev train operation safety. Aiming at the layout of the ASA along the track, this article constructs an optimized model of ASA layout and proposes a solving algorithm based on the single target genetic algorithm by analyzing the influence factors of ASA layout. The result of the numerical experiment shows that the proposed method could fulfill the requirements of the maglev train operation safety and efficiency and optimize the cost of the ASA layout while taking the complex line situation, train tracking operation, and bidirectional operation on a single line into account. [ABSTRACT FROM AUTHOR]

Automatic train operation (ATO) system is one of the important components in advanced train operation control systems. Ideal controllers are expected for the automatic driving function of ATO systems. Aiming at the intelligence requirements of the systems, an NSGA-II-based parameter tuning method for the fuzzy immune PID (FI-PID) controller and a grey model GM(1,1)-based fuzzy grey immune PID (FGI-PID) controller were proposed. Taking a maglev train's model as the control object and a velocity-time curve as the input, the feasibility of the parameter tuning method for the FI-PID controller and the applicability of the FI-PID controller and the FGI-PID controller for the ATO system were tested. The results showed that the optimized parameters were ideal, the two controllers all showed good performance on the indicators of traceability and comfort level, and the FGI-PID controller performed better than the FI-PID controller. The results exhibited the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]