Time–Space Conflict Management in Construction Sites Using Discrete Event Simulation (DES) and Path Planning in Unity

Round 1

Reviewer 1 Report

This paper focuses on time-space conflict management in construction sites using discrete event simulation (DES) and path planning in Unity. In general, this paper is interesting and some comments are listed as follows:

1.      Some of the mathematical symbols in the paragraphs are not fully displayed. For example, the name of the node in line 118.

2.      The node circle in the upper right corner of Figure 1 is not fully displayed.

3.      Some figures in this paper are of low clarity, and the resolution and clarity need to be improved.

4.      The layout of the article needs to be further improved, such as the cross-page display of the table, which can be slightly adjusted to make it as beautiful as possible.

5.      The pseudo-code of the algorithm should be written in a format that conforms to the programming language as much as possible. for loops and if statements need to be ended with an end.

6.      The discrete event simulation method is used in this paper, and the correlative simulation process diagram is given. The detailed steps and process of the method can be further explained to help readers understand the research content.

7.      The content of simulation experiment in this paper is relatively simple. Simulation scenarios or different obstacles can be appropriately added to prove the feasibility of the method.

8.      The discussion and analysis of the simulation experiment in this paper can be further developed, and the feasibility and shortcomings of the research content can be explained in detail.

9.     Neural network based path planning technique should be included in the literature part, e.g., A Neural Network-Based Navigation Approach for Autonomous Mobile Robot Systems, Applied Sciences 12 (15), 7796

Minor editing of English language is required.

Author Response

Please find the responses in the attached document.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear respected authors,

1. The abstract section needs to be revised. The main part of the first half of this section should be moved to the Introduction section, and the main findings and results should be mentioned at the end of this section.
2. Generally, keywords should be selected based on the high repetition or importance of the phrases in the text. But some of the phrases in the keyword list have not been mentioned in the text, like "informed rapidly exploring random trees," or have been mentioned just once, like "time-space planning. Hence, the keyword list needs to be revised.
3. Acronyms and abbreviations should be used in the whole text after the first time they are defined. Considering this issue, "DES" should be used instead of "discrete event simulation" everywhere after subsection 2.2, and there is no need to be defined again as mentioned in line 187 in section 4. In addition, "BIM", line 83, should first be defined, and then it might be used. The whole text should be checked, considering these issues.
4. The introduction section needs to be revised. The "time-space conflict" should be defined the first time it is mentioned. The contents in lines 42 to 46 are a repetition of the same sentences mentioned in the Abstract section that should be revised or eliminated.
5. The sectioning of the study needs to be revised. Section 2 is not the real background of the study. The majority of the part, containing figures, pseudocode, etc., is related to the problem definition, which should be moved to the next section, and a small part of it might be mentioned in the Introduction section. However, the literature gap should be highlighted after covering the related literature.
6. Unify using "Fig." or "Figure" in the text.
7. The content of Figure 16 is not clear. Please replace it with a better one.
8. Figures 17 and 18 can be mentioned in the appendix. Instead, the information can be mentioned in a table for ease of readability.
9. After the publication, as many of the readers print the article to read, it is suggested to use a different shape or type beside the red and blue cubes, etc., for SmallTruck.
10. It is recommended to add a section entitled "Discussions" before the Conclusion section to compare the results of the methods used, like simulation, mathematical modeling, etc., and discuss the differences.

1. The English of the text should be checked. There is no need to write words starting with a capital letter in the middle of a sentence. For instance, "specifically" in line 34 should be modified to "specifically". Please check the entire text.

Author Response

Please find the responses in the attached document.

Author Response File: Author Response.docx

Reviewer 3 Report

The publication is interesting and addresses an important issue. However, the objective of the study is ambiguously formulated. The methods should be better described. The presented model is poorly presented with limited clarity. The abstract is very general. The conclusion is too general.

Author Response

Please find the responses in the attached document.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have addressed all my comments.

Minor editing of English language is required.

Reviewer 2 Report

Dear Authors,

The manuscript's content has been modified according to what the reviewer recommended. All the comments and suggestions of the reviewer have been met. According to the reviewer's point of view, the manuscript is worth being published in the respected journal of Applied Sciences.