An Integrated Optimization Method of High-Speed Railway Rescheduling Problem at the Network Level

Round 1

Reviewer 1 Report

An integrated optimization method of high-speed railway rescheduling problem at the network level

Manuscript Number: applsci-2597293

Comments:

1)     This manuscript is well-written and well-organized. However, the authors are encouraged to double-check it regarding grammatical and punctuation mistakes. Additionally, some statements should be rewritten to be more transparent and avoid misunderstandings. For example:

·       “For high-speed railway (HSR) operations at the network level, unforeseen events that lead to operation interruptions are inevitable and we call them emergencies.” Edited: For high-speed railway (HSR) operations at the network level, unforeseen events that lead to operation interruptions are inevitable, and we call them emergencies.

·       “The operator should handle the emergencies within a short period of time, so as to reduce the influence of the emergencies as much as possible.” Edited: The operator should handle the emergencies within a short time to reduce the influence of the emergencies as much as possible.

·       “In this paper, an integrated optimization method is introduced to deal with reschedule problems at the railway network level under the circumstance of emergencies, rescheduling the train timetable and the utilization of the train-sets.” Edited: This paper introduces an integrated optimization method to deal with rescheduling problems at the railway network level under emergencies, rescheduling the train timetable, and utilizing the train sets.

·       “A multi-objective optimization model is formulated to minimize additional operation costs, total delay, and the number of transfer passengers.” Please rewrite this sentence because it matches with the following reference: https://doi.org/10.1002/9781119848899.ch18

·       “High-speed railway (HSR) has been developed worldwide rapidly in recent years and plays an increasingly important role in passenger transportation, especially in China.” This sentence matches with the following reference: Wen-qi, Liu. "On the Translation of Accounting English." Journal of Jiangxi Agricultural University, 2003.

·       “In such a complex network, once an emergency occurs in a section of a railway line, many trains will be delayed and wait for the emergency management and the train operation will be influenced.” Edited: In such a complex network, once an emergency occurs in a section of a railway line, many trains will be delayed and wait for emergency management, and the train operation will be influenced.

·       “So, it is of vital importance for the operators to deal with the emergency, so as to avoid the operation of the railway network being influenced as much as possible.” Edited: So, it is vital for the operators to deal with the emergency to avoid the railway network's operation being influenced as much as possible.

·       “Besides dispatching standby train-sets and coupling short trains, some other dispatching methods are also efficient, such as adjusting the arrival time and departure time of the train, changing the sequence of delayed trains, and cancelling trains.” Edited: Besides dispatching standby train sets and coupling short trains, some other methods are also efficient, such as adjusting the arrival and departure times of the train, changing the sequence of delayed trains, and canceling trains.

Please carefully review the manuscript and fix all grammatical and punctuation bugs before submitting the revised version.

2)     The visibility of Figure 13 could be better. Besides, It would be great if the authors could mention whole symbols in the text instead of Tables 1 to 3. In its current form, readers are forced to return to Tables and may find it difficult.

3)     Please show that your optimization algorithm properly minimizes the objective function. For example, the authors are encouraged to plot convergence curves.

4)     Please run the optimization algorithm several times and calculate the mean value and standard deviation to show reliability and reproducibility. For example, authors can refer to the following reference and consider the presented calculations to show the reliability of the optimization procedure. https://doi.org/10.1016/j.istruc.2023.02.008

5)     It would be significant if the authors could mention traditional and novel optimization algorithms in the introduction section and discuss their advantages and disadvantages based on recent literature. Additionally, the objective function plays an important role in the accuracy of obtained solutions.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The presented article presents a problem frequently encountered by those who operate as traffic managers on railway networks.

  Optimizing these processes is difficult and for this reason the need to optimize these processes arises.

Regarding the bibliography of this study, is comprehensive and specific to this subject.

In the introduction, aspects related to the necessity and opportunity of this study are specified.

I believe that the abstract should be reformulated because it is very similar to the introduction part.

In terms of optimization, the objectives of the study were clearly formulated: Minimize additional operation costs, Minimize total delay, and Minimize the transfer number of affected passengers.

Also the constraints include 3 types: Constraints of train timetable, Constraints of train-sets circulation plan, and Constraints of passenger demand.

The NSGA-III Algorithm was presented in detail: Conception, Representation Scheme, Initial populations and infeasible solution adjustment, Decoding, Fitness function, Crossover, Mutation, Termination conditions, and Algorithm.

Here it should be 4.3 ” 4.2. Initial Populations and Infeasible Solution Adjustment" and must be changed.

The study has both a well-presented theoretical part, but it is also shown in a case study where the optimization of the processes is observed.

Regarding the conclusions, these do not contain whether the objectives previously indicated in the study were resolved. This is very important.

 

Overall, the article is good, but I think it is necessary to review/correct and consider the indications made previously.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The article is devoted to a complex method for optimizing the problem of restructuring high-speed railways at the network level. A multi-objective optimization model has been formulated that allows minimizing additional operating costs, total delay and the number of transfer passengers. To solve the model, an algorithm based on NSGA-III is proposed. The adaptability of the model and algorithm was tested on real instances of the HSR network in China.

However, there are some remarks about the work:

1. The Abstract section must be rewritten, reflecting in it not only the relevance of the problem being solved, the scientific novelty of the solution obtained, but especially the results obtained. Abbreviations should be removed from the section by moving them into the text of the article.

2. Keywords also need to be corrected, highlighting special terms in them.

3. Figures 2 and 3 should be made more readable, especially the captions on the figures. This also applies to other figures in the article, such as Figures 12 and 13.

4. In the Introduction section, the relevance of the study should be indicated, it is not presented. At the end of the Introduction section, it is necessary to define the purpose of the scientific research.

5. The list of cited sources should include more modern publications on solving the problems of railway restructuring, for example,

https://doi.org/10.3390/en16093909

https://doi.org/10.3390/su132111933

https://doi.org/10.3390/en14164814

http://dx.doi.org/10.1109/CAC51589.2020.9327177

6. How are random factors of train departure time delay taken into account in the presented traffic model?

7. There is no Discussion section, which allows to characterize the obtained models and obtained scientific results, describe their advantages and disadvantages, as well as present the limitations of the resulting transport model.

8. Factors should be clearly defined and weighted to influence the high-speed rail optimization model at the network level.

9. The conclusions must be structured, highlighting the main obtained scientific and practical results, giving numerical characteristics of the obtained effective solutions.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors answered my questions and revised the article. The article has become significantly better.

The article may be published in my opinion.