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High-speed railway (HSR) transportation poses a serious challenge to dispatchers, whose job performance plays a critical role for the safety and efficiency of the transportation system. This study examined the relationship between cognitive and mental factors and job performance among Chinese high-speed railway dispatchers and established a predictive model for the job performance of dispatchers. Cognitive abilities involved in train dispatching including working memory and multiobject tracking and potential related mental factors including depression, anxiety, perceived stress, and social support were examined. Job performances were measured by both subjective and objective indicators, i.e., the overall evaluation by supervisors and the delay time by dispatching simulator. Stepwise regression results showed that both cognitive abilities and 2 mental factors (depression and perceived stress) have strong relations with job performance, and tremendous distinction between groups of good and poor performance of HSR dispatchers is revealed. The predictive model accounted for 91% of the overall variance in objective performance indicator and has 96% distinguished accuracy of good and poor groups. These findings imply that cognitive and mental factors should be of great concern to the current practice of Chinese HSR dispatcher selection and management.

Most scholars of purchasing and supply management (PSM) are familiar with some form of a purchasing process model (PPM). A PPM is the visual representation of the sequence of activities that constitute purchasing and supply management. Such a visual representation can be a tool in teaching PSM since it gives students an overview of an otherwise intangible process. Moreover, a PPM can also be viewed as a representation of the identity of PSM, providing a schema of what is PSM (and what it is not). In this notes and debates article, a systematic overview of different types of PPMs, and their evolution, is presented, based on a literature review and a survey, with the models being classified as tactical/operational, strategic, cyclical, or decision-making processes. Our first aim is to inspire PSM scholars and educators when they are considering various PPMs to be used in their teaching of PSM. Our second aim is to debate the question where the evolution of PPMs is heading and explore whether a single holistic model can provide an accurate and representative framework to structure purchasing activities both today and in the future.

Many work zones exist in the urban road network and have a great negative impact on city traffic. Finding the optimal work zone schedule can minimize the negative impact of work zones on traffic. This paper focuses on the day-based work zone scheduling problem in the urban network. Existing studies on the day-based work zone scheduling problem do not consider the progression of day-to-day traffic from a non-equilibrium state to an equilibrium state during the construction period. For the first time, this paper proposes a model for day-based work zone scheduling by introducing a day-to-day traffic assignment model, in which the target of the optimization problem is minimizing the increase in travel cost caused by work zones. Numerical examples are presented to explore the variations of the optimal construction sequence for different work durations, crew numbers, and model parameter values. Some new findings are obtained in the paper. When the construction duration of each work zone is relatively short (for example, less than 20 days), the optimal scheduling will obviously change with the work duration; when all of the construction durations increase to a threshold (for example, 60 days), the optimal construction sequence will no longer change. An optimal crew number exists that can minimize the increment of travel cost caused by work zones. During the construction period, the total travel cost in the network can be decreased by guiding travelers to change their original travel habits.

In this paper, we named the composition by a real-valued measurable function and an uncertain variable as a composite uncertain variable. We focused on the uncertainty distribution for two kinds of composite uncertain variables. The conclusions show: (1) it exists a lower bound when the composed function is continuous and strictly monotonically decreasing at first and then strictly monotonically increasing (e.g. convex downward functions); (2) it exists an upper bound when the composed function is continuous and strictly monotonically increasing at first and then strictly monotonically decreasing (e.g. convex upward functions).

Wagon flows organize and optimize on railway regional networks. They not only consider apparatus and personnel, but also organize and coordinate from every operation link. After analyzing wagon flow routes and train formation plans, an optimization model was established for wagon flow organization on railway regional networks, in which the objective functions were total minimum cost including accumulation cost, resorting consumption, handling expense and operation cost on railway line. Two constraint conditions included line carrying capacity and station resorting capacity. This model can confirm the choices of train formation plan and wagon flow route.

The car-to-block assignment plan (CBAP) is one of the sub-problems and foundation of the train formation plan (TFP). When two 0-1 decision variables corresponding to block plan and car-to-block assignment were introduced, a model of generation of all possible CBAPs was established with the constraints of non-circuit, maximum frequency of reclassification, cross relation and cutting off unfavorable plans. In the block network (service network) whose nodes represent stations and arcs stand for blocks between two stations, a CBAP is equivalent to a shortest path (SP). Based on this, a backtracking algorithm was provided. Finally, the practical feasibility and effectiveness was verified by an example.

Dispatching problem in marshalling yard is that one has uncertainty, multiple objectives, and it integrates synthetically. Its intelligent dispatching system is a complicated system too, difficult to describe with an accurate mathematical model. The integrated design principle and technology element of yard intelligent dispatching system (YIDS) have been analyzed by using system thought and theory, the comprehensive integrated framework was put forward, and then its complexity was analyzed from a lot of respects, such as system goal, system attribute, system environment, technology system, subsystem, etc. This has pointed out the direction for further research of yard intelligent dispatching system.