Modeling Aircraft Departure at a Runway Using a Time-Varying Fluid Queue
Round 1
Reviewer 1 Report
1. The introduction description logic is not clear, and the research subject of the article is not clear;
2. The result lacks comparison and cannot reflect the effectiveness and universality of the algorithm;
3. The parameters of the algorithm are not defined, and the explanation of the formula is not clear (such as G¯(x) and hG(x), etc.);
4. Table1 is unclear, it should be clarified whether it is a proportion or a count.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper presents an aircraft departure model at a runway using a time-varying fluid queue. This topic is very interesting. However, the current version is not well prepared. There are some major comments:
1.The format of references is not uniform. For example, references[2] and [4] was different from others.
2.Introduction and literature review section's should be summarized with applicability view.
3.In model formulation, there are a lot of undefined variables,such as
b(t,x),q(t,x)
4. There is no connection betweenthe five-tuple of functions; λ(t), s(t), G,b(0,·), q(0,·).In particular, how does key imput λ(t) affect them.
5. Although the aircraft departure process can be thought of as a queuing system, λ(t) are generally determined by flight schedules and controllers. In general, it is a discrete time system, not continuous time system. If a time-varying fluid queue is used in this study, the influence of different random distributions for inputs on queue is not the same. The article lacks relevant description.
6.What's time-varying of λ(t) at minute or hour. Is it a given value for each moment in advance, or is it a function of time.If it is the former, the integral form of the model is worth discussing. If it's the latter,the probability density function (pdf) of λ(t) is necessary.
7.The paper lacks the difference between model estimation and actual queuing.
8.There are no formulation for estimating ecological and economical impacts due to departure queue.
9.Is there any difference in the queuing process of different aircraft types.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Please consider the comment in the attached file
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
This paper is a very descriptive analysis of operations at RJTT.
Overall, I am very reluctant to accept it (at all) as I don't clearly see what the contribution is. I would may be say "accept if room" in a conference, but this feels really light for a journal.
The paper reads ok, but it overall feels very rushed (eager to submit before Dec 31?). I am particularly concerned by the following points:
- the lack of a significant bibliography outside authors' contributions;
- even without a serious bibliography, I don't see how this work stands out, what the real contribution is
- the lack of a description of data sources: computations are made but nobody knows what it is based on, official/open/confidential data (there is a hint in the acknowledgement but it would have deserved a proper section)? what about trajectories? what about airport layout? how is it modeled?
- no details about fuel flow estimation on ground. There is some literature about fuel flow estimation in cruise or climb phase. I am not a specialist here, but I would expect details about how you deal with that on ground. Of course, you need to be transparent about the data you use then (see previous point)
- "so what?" what does it all serve? you have plots but I don't see results. "an average of 2.5h waiting time was estimated" is no rocket science, it just sounds like an observation, the result of a straightforward computation. But what are we supposed to do with it? Airports are supposed to reproduce the results? If there was some kind of optimisation strategies presented in order to cut that 2kton down, the paper could make sense, but it's not the case here
- the lack of a credit statement: the use case chosen, and the typo in the author's name (did I read right? it looks inconsistent between the first page and the entries in the bibliography) makes me think of a solo paper rather than a team work. Happy to be wrong, but this does not look serious...
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
1.the difference in Time-varying states between model estimation and actual queuing in Figure 14 is necessary
2.Many factors affect Estimating ecological and economical impacts related to departure queue. It is very complicated. It is not a necessary part of this article.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Thank you for taking most comments into account:
- bibliography issue: not addressed;
- data sources: solved;
- fuel flow estimation: I am not convinced but I don't have better ideas. But now the reader can make his own opinion, which is good to me;
- so what/departure metering: I think I got it more clearly now, but I think the introduction still needs a major refactoring, let me explain below;
- credit statement: solved
So on the whole, I see better the point of your paper, but still see major issues, esp. in Section 1/Introduction. Maybe it is for a big part a language issue, but here goes:
- line 9: "discussed using a validation criteria" can you be more specific? no need to write 10 lines, but this is unclear;
- line 23: inappropriate self-citation you are bulk citing 9 of your own papers which are only loosely related to this analysis, while ignoring other aspects of your own work which would be (in my opinion) more relevant. I think the following papers (your papers!) are more relevant with respect to this study:
- https://www.mdpi.com/2226-4310/8/6/152
- https://doi.org/10.1016/j.jairtraman.2021.102164
- line 40 and the rest of the paragraph should be refactored. Maybe make two paragraphs, one for explaining departure metering (I would put first occurrence in bold characters, but that's just a soft recommendation) and another one with the queuing models?
- line 64: the study aims to propose a new departure metering approach
line 69: we propose a departure queue model [...]
line 97: this paper develops a methodology to...
=> please clarify the objective of the paper once for all - line 127 typo: "the all air traffic data"
- line 137: "toward a..." => do you mean "in order to"?
- line 241: you start Section 4 with "In Section 4" with a self-recursive hyperlink, that is awkward
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 3
Reviewer 4 Report
line 9: the sentence before the red addition does not make sense
line 23: [2-6], [7] what's the point of this remaining self-citation. I don't question 2/3 of your own papers, but this practice is just embarassing for yourself. I don't understand why you pretend not to understand the concept of abusive self-citation.
I am ok with other corrections. For now, I'll flag the self-citation again and let the editor decide. If it comes back to me as is, I'll reject.
Author Response
Dear reviewer, we justified the reference to our own research and provide a more detailed description on how we build on our prior approaches.
References 2-7, 16 and 17 are self-citations.
After revision, references 5-7, 16 and 17 and lines 22-27 which contained references 2-7 have been deleted. References 2-4 have been renumbered 16-18 and are cited in a new paragraph (lines 84-94) where justification for their citation is provided.
