Round 1

Reviewer 1 Report

This paper gives a substantial investigation of the radio signal propagation for UHF RFID technology in an indoor environment using the graphical ray tracing method. The considered topic is interesting and useful. Nevertheless, the reviewer holds some concerns about this work which you can find below. I suggest that the authors revise and improve the manuscript accordingly.

 

Although the authors have done a lot of work, the novelty of this manuscript is not very specific.

 

Some of the similar works on radio wave propagation may be helpful for the authors for literature review, e.g., Terahertz waves propagation in an inhomogeneous plasma layer using the improved scattering-matrix method, ELF wave propagation simulation using FDTD method and satellite constellation concept for early warning system

 

For professional terms or methods, they should be highly consistent. For example, "ray tracing (graphics) method" in the text and "Graphical Ray Tracing Method" in the title.

 

There are many grammars and writing mistakes. For example, "The conclusion of this paper is given in Section 4."

 

It is suggested to redraw Figure 1 for readability.

 

The label of Figures 3 and 4 are not written correctly.

 

Figure 5 is not clear, and the font size and font format in the figure are inconsistent. The authors should check it carefully.

 

In section 2.6, the author should correct "see Figure 3 and Figure 3"

 

Section 2.7 is one of the most important parts of the paper, and the authors should analyze this section in detail and explain the complex phenomenon in Figure 9 and Figure 10.

 

More explanations should be provided in Figure 5. Are the simulation times of antenna #1 and antenna #2 the same?

Author Response

Hello, thank you for your review. The answers to your questions can be found in the attached PDF and in the new version of the article.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Editor and authors

I have completed the review of the article. My comments and recommendations are below

- The study focuses on ray tracing-based EM propagation estimation for RFID applications. SketchUp and V-Ray tools are used for this.

- Although the study presents the results of an experimental study, it does not suggest a new perspective. This should be more accurately emphasized in the introduction.

- More detailed background about ray tracing algorithms should be given.

- The electrical and magnetic properties of the medium and the material should be given (for example, Permittivity and conductivity coefficients)

- Only the Multi-Wall model was used for comparison. At least one empirical model should be added

- Are there any thresholds for refraction and reflection phenomena in the RT used?

- Current studies made in recent years, especially those made with artificial intelligence methods, can be added. Some of them are

          -  A ray launching-neural network approach

for radio wave propagation analysis in complex indoor environments

      - 3D shooting and bouncing ray approach using an artificial

intelligence-based acceleration technique for radio propagation prediction in indoor environments

 

Comments for author File: Comments.pdf

Author Response

Hello, thank you for your review. The answers to your questions can be found in the attached PDF and in the new version of the article.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors,

Thanks for your contribution to Applied Sciences.

Before further process of this manuscript, please check if it matches the scope of the journal.

 

With minor revision of the manuscript, it might be accepted.

The opinions are set out below:

 

 

STRUCTURE 

Please prepare the manuscript following the instructions for authors. 

Abstract should be rewritten.

 

ENGLISH

The manuscript has several typos. Authors need to proofread the paper to eliminate all of them.

Some sentences are too long. Generally, it is preferable to write short sentences with one idea in each sentence.

 

REFERENCES

The literature review is incomplete. Several relevant references are missing. The reference list should include the full title, as recommended by the style guide.

 

INTRODUCTION 

Authors should include additional references in the introduction that support the claims. Authors should better explain the background to this research, including why the research issue is important. Contributions should be enhanced. It should be made clear what is novel and how it addresses the limitations of prior work.

 

RELATED WORK 

The related work section is not well organized. Writers should try to categorize articles and present them logically. Authors should add a table comparing the main features of previous work in order to highlight their differences and limitations. Alternatively, authors may consider adding a row to the table to describe the proposed solution.

 

PROBLEM DEFINITION 

Authors should provide a clear and detailed definition of the issue. Authors should include an example to illustrate how the problem is defined.

 

METHOD

A novel solution is presented, but it is important to better explain the design decisions (e.g. why the solution is designed that way). There is a need for discussion of the complexity of the proposed solution.

 

SIMULATION 

Simulations should be updated to incorporate some comparisons with more recent studies.

 

 

Sincerely yours,

 

Author Response

Hello, thank you for your review. The answers to your questions can be found in the attached PDF and in the new version of the article. Thank you.

Author Response File: Author Response.pdf