# An Integrated Optimization Method of High-Speed Railway Rescheduling Problem at the Network Level
## 2 Literature Review  
In order to deal with emergencies in the process of train operation, researchers have conducted many valuable studies on the rescheduling of train operation plans. For the scope of these studies, some studies focused on a railway line and some studies concentrated on the railway network; for the objects of these studies, some studies mainly focused on train timetable rescheduling, some studies focused on train set circulation plans and a small part of them studied integrated rescheduling methods of train timetable and train sets circulation plan; for the algorithms, many kinds of algorithms are used and they have  
Figure 3: Spatiotemporal operation process of some dispatching methods after the emergency occurs. advantages and disadvantages; and for the optimization objectives, they can be divided into single-objective and multiple-objective. At the level of the railway line, [PERSON] et al. [1] proposed a novel approach to solve the train re-scheduling problem and train control problem synthetically. It also provided supporting information for both the train drivers and the operators to improve the schedule rate and reduce energy consumption. [PERSON] et al. [2] proposed a mixed-integer programming model to balance the operating mileage of bullet trains. They considered the limitation of maintenance capacity and used an improved genetic algorithm to solve the model. [PERSON] et al. [3] proposed a method to reschedule the bullet train operation plan based on the current train timetable. They realized the transition from the old train timetable to the new one. [PERSON] et al. [4] studied a mixed-integer linear programming model for a busy Dutch railway line to obtain the best plan, which includes the station for the train to turn back and the time the train costs. The results show that the plan is related to the length of the emergency period, and a longer period will lead to more train cancellations. Train operation rescheduling problems on a railway network are also of vital importance. [PERSON] et al. [5] present a mixed-integer nonlinear optimization model of a high-speed railway line planning problem, integrating the operation route plan, train stop plan, and passenger distribution plan. Moreover, a two-stage hybrid heuristic search algorithm is designed to solve this model. [PERSON] al. [6] provided a multi-commodity flow model for train timetable adjustment, considering recent train maintenance needs, and tested the model on the Dutch railway network. [PERSON] et al. [7] and [PERSON] et al. [8] proposed a mixed-integer linear programming model to describe the train operation problem and finally solved it with CPLEX. [PERSON] et al. [9] solved the first train scheduling problem to find an optimal scheme by adjusting the total number of skipped stations and the headway of the first deadheading train and tested the method on the Nanjing Railway network. Train timetable rescheduling plays an important role in the daily operation of the HSR. Thus, some studies mainly focused on train timetable rescheduling under emergency conditions. [PERSON] et al. [10] built a mixed-integer linear programming model to make decisions on which trains should be retained in case of train delay. [PERSON] et al. [11] studied the rescheduling of train timetables at the macro level of the railway network. With the objective of minimizing the number of canceled trains and delayed trains, an integer programming model is developed and tested on the Dutch railway network. [PERSON] [12] established the train operation adjustment model of HSR with the objective function of minimizing the total weighted delay time of the section, and then combined the genetic algorithm and simulated annealing algorithm to solve the model. [PERSON] [13] divided the adjustment strategies into two cases when the normal operation status was slightly disturbed and seriously disturbed and used the grey wolf algorithm and the receding horizon algorithm to solve the problem.