Comprehensive Study on Optimizing Inland Waterway Vessel Routes Using AIS Data

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I see potential in the work. However, the novelties and contributions are not described. 

I suggest to rewrite the introduction. The research problem, objectives, contributions, and novelties must be clear. 

The authors must be careful to correctly use citations and their own statements. In the manuscript, sometimes, the authors make statements about common or typical methods or algorithms without any evidence (or reference) that they are typical or common. Also, the authors refer about their proposed method that seems to be an improvement of an existing method which doesn't perform as desirable, but this existing method is not cited. 

Table 1 is not properly explained and discussed in the text. 

Many acronyms are used without definition. I suggest to include a list of abbreviations and acronyms. 

There is no citation after section 1.

Method/algorithm definitions must be based on references. For example, the DP algorithm is not a contribution from this work, so in section 2.1, the authors must cite a reference (it can be the same one cited in section 1).

The authors cited limitations in the study. It is crucial to explain these limitations and show how they affect the contribution, applicability, and feasibility.

As the objectives, contributions, and novelties are not defined, it is impossible to evaluate sections 2, 3, 4, and 5 properly. When the authors rewrite section 1, many corrections will probably need to be made in the other sections. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

 

Comprehensive Study on Optimizing Inland Waterway Vessel Routes Using AIS Data

 

The article analyses an important issue related to shipping safety and efficiency. Identifying the basic routes allows decisions to be made about capacity and how to maximise it, as well as the support systems needed to mitigate risk. The article is well structured and the text is easy to read.

 

What I particularly like is that all the procedures are described in detail. It is easy to follow how the data is processed and what the results are.

 

My experience with route analysis is only from the open sea, which is a much less constrained environment.

 

Something missing from this article is the problem of incorrect AIS data: on-board systems sometimes fail to provide correct data. Another problem is the fact that AIS data is sometimes not received or not stored by the receiver. How did the authors deal with this?

 

On page 8, formulae 1 and 2 form the basis of the MPDP algorithm. Unfortunately, there is no explanation of how this works. Firstly, how is the normalised distance defined, and secondly, how is the constraint set by formula 2 implemented?

 

On page 13, formulae 9-12 are a bit confusing. The 'x' to me is a vector product, but there are no vectors here. And an 'e' in relation to 'sin()' is for many readers the mathematical constant 'e', which is not the case here. Also, please be clear whether angles are in degrees or radians, and do not change them.

 

While the general routes found will be correct in themselves, the routes may be intentionally slightly different because different tactics may be used to deal with the constraints. The results of the analysis proposed in this article will ignore these differences. Do the authors have any idea how to deal with this?

 

What may be a shortcoming in the reporting of the results is that it is not clear at first glance what the optimisations are: a shorter route for the ship, or less data to process. Some of the real routes have an odd shape at first sight, but may be perfectly logical on further analysis. The authors should make it clearer what the improvements are.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is interesting, well-prepared, and thoughtfully structured. Its findings are significant from the perspective of optimizing inland waterway shipping routes, which has implications for environmental protection, financial savings, and long-term reductions in travel time.

Here are detailed comments regarding both the editorial and substantive aspects of the paper.

Lines 33-34: According to the template, individual keywords should be written in lowercase.

Line 55: Add a space between “algorithm” and “[1]”, and similarly in lines: 110, 111 (3x), 117, 119, 121, 124.

Line 55: “RRT algorithm” - provide the full name: “a rapidly exploring random tree,” especially since its full name is used in Table 1. I suggest giving the full name + the acronym in line 55, and only the acronym "RRT" in Table 1.

Table 1: Adjust the table to the template: headings of particular columns should be bold.

Line 98: Explain the acronym DWA. Similarly: MDA (line 101), DBSCAN (line 102), STTrace (line 111).

Line 297: “distance(Core…” – add a space before the parenthesis and simultaneously remove the space after it.

Line 304: Move the comma at the beginning of the line to the end of the previous line.

Line 306: There is a missing space between “q,” and “which”.

Line 341: It should be “Equation (7)” instead of “Equation (5)”.

Line 342: It should be “Equation (8)” instead of “Equation (6)”.

Lines 366-371: Is the order of the variable explanations random? For the reader, it would be most convenient to list the explanations of the variables in the order in which they appear in equations 9-12. Similarly: lines 377-380.

From line 427 to the end of the manuscript: The main text should be justified (currently, the right margin is not aligned).

Line 468: Considering equation (19), please ensure that the subscript for x’ and y’ should not be i instead of j (2x)? (x'_i,y'_i) and (x'_i+1,y'_i+1).

Fig. 9b: What does the scale on the horizontal axis represent? Please add a label to this axis.

Fig. 11 and Tab. 3: Please refer to and comment on Fig. 11 and Tab. 3 in the main text.

Lines 483-490: It would be better if this paragraph were placed before Fig. 10.

Tab. 4: I suggest using the singular form for the header of the first column: “Algorithm” instead of “Algorithms”.

Line 523: Since you mentioned what the red dots represent here, it would be good to explain at this point what the other colors on Fig. c mean (mentioning this only in line 533 seems too late).

Line 540: “As shown in the figures…” – I suggest specifying that you are referring to Fig. 15-16.

Line 572: “Figures 14–16” - wrong number of figures.

Summary: Based on the conducted research and the optimization of routes in the studied area, can you estimate the economic benefits this has brought (e.g., over the course of a year) - how much fuel was saved? How much was the crew's working time reduced? It would be good to list other benefits. Then, outline the financial advantages. My idea is to show that the proposed optimization makes sense and provides tangible benefits – this would strengthen the results and the thesis that the proposed optimization is necessary.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Congratulations on your work. You improved the first manuscript, and now it is possible to identify your contribution and novelty.

However, some points need to be clarified and improved.

1. The paper's abstract focuses on route optimization. However, the text does not reflect the same emphasis. The focus is on the MPDP algorithm and the OPTICS algorithm. I suggest including in the abstract the gains achieved using MPDP and OPTICS.
2. A* algorithm - I understand you didn't adapt the algorithm, you applied it to find the paths.
   1. Provide some explanation of why you chose this algorithm.  It can be based on references.
   2. As you are applying and haven't adapted or developed the algorithm, put the exact reference of the algorithm you are using, the parameters used, and the performance. Put a short explanation.
3. NSGA-II algorithm - I understand you didn't adapt the algorithm, you applied it to optimize the route.
   1. Provide some explanation of why you chose this algorithm.  I believe it is because the NSGA-II is suitable for Multi-objective problems. However, it is not explicit in your text.
   2. Talk a little about the complexity of the problem. Why is it not possible to use an exhaustive search algorithm?
   3. As you are applying and haven't adapted or developed the algorithm, put the exact reference of the algorithm you are using, the parameters used, and the performance. NSGA has many parameters; put the values and a short explanation about each one.
   4. Since NSGA-II has random components, you must run it several times for each instance during the experiments to obtain a confidence interval for your results. You might find other points on the Pareto front.
4. Route planning experiment
   1. Which point in the Pareto front did you choose? Why this point?
   2. Avoid using the word Simulation. Simulation algorithms can be used to analyze problems, but you are not using Simulation.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Now, I believe we are very close. Congratulations on the work.

 

I still have some observations and questions.

1. I suggest including your response 3a (in a proper format) in the manuscript.
2. I was thinking about Table 8 when I wrote about the confidence interval, but I wrote it in the wrong place. Do you have the confidence interval for Table 8 results?
3. Now related to Figure 17: When you run 30 times, did you find new points on the Pareto front? Or did you find the same points every time?

Thanks

Author Response

Please see the attachment.

Author Response File: Author Response.pdf