Algorithms for the Structural Analysis of Multimode Modelica Models

Round 1

Reviewer 1 Report

Comments for author File: Comments.pdf

Author Response

See attached cover letter.

Author Response File: Author Response.pdf

Reviewer 2 Report

I read the work with great curiosity. The discussed topic is important from the perspective of effective methods of multi-mode DAE model analysis, which is common in cyber-physical systems modeling and simulation.  I would like to convey my comments and suggestions to the Editor and Authors of the work. However, the article is too long and many details can only be skimmed through at a glance.

 

This paper aims to the structural analysis of multimode Modelica models and introduces several contributions to this problem. The authors divide the evolution of multimode models into four classes: "initialization", "long mode", "mode changes", and "transient modes" and systematically study the problems in structural analysis. Their contributions include:

(1) a dual representation of multimode models that allows the analysis of a multimode model in an "all-modes-at-once" fashion. The DM decomposition method and Pryce's Σ-method are extended for the dual representation of multimode models;

(2) an efficient decompositional method, called CoSTreD, for the solving of multimode constraint systems;

(3) a novel approach for the consistent initialization of multimodel models;

(4) a mathematically sound, physics-agnostic compilation process handling modes and mode changes in a unified framework;

(5) an automatic transformation method, called RIMIS, for multimode Modelica models. 

 

The abstract is accurately related to the problems and the obtained result. The introduction and conclusion are comprehensive. The research is professional and rigorous. The methods are adequately described. Every reference is well cited in the content. In my opinion, this work can be accepted for publication after minor revision.

 

Some minor issues that can be improved:

(1) Some abbreviations do not provide full words in the first place where they appear, such as mDAE(P13, L357),  SA(P15, L452), and CoSTreD (P4, L143). 

(2) Some symbols are undefined or ambiguous, such as double-struck B (P12, L247),   σi,j(P13, L355). Do the double-struck M and the Mathcal M in Table 1 and Table 2 have the same meaning?

(3) Some figures are cited in different styles, such as Fig.8(P8, L254+),  Figure(21) (P36, L1193), Fig.23(P38, L1246), and Fig.24(P39, L1252).

(4) The citation "2" (P31, L1039) should be "Table 2".

(5) The work solving multiple problems in the structural analysis of multimode models. How these methods work together and contribute to the "structural analysis of multimode Modelica models" requires a clear outline introduction. In addition, the article is too long (60 pages). Is it possible to simplify the non-key sections and put some details, like example details in section 2, in the appendix? I don't know if article length is an important issue in special issues.

 

Author Response

See attached cover letter.

Author Response File: Author Response.pdf

Reviewer 3 Report

Algorithms for the Structural Analysis of Multimode Modelica Models

Review Report

 In this paper, the authors propose several contributions to this multifaceted issue, namely: an efficient and scalable multimode extension of the structural analysis of Modelica  models; a systematic way of rewriting a multimode Modelica model, based on this analysis, so that the rewritten model is guaranteed to be correctly compiled by state-of-the-art Modelica tools; a  proposal for the handling of the consistent initialization of multimode models; multimode structural analysis algorithms that handle both multiple modes and mode change events in a unified framework, coupled with a compile-time algorithm for identifying and quantifying impulsive behaviors at mode changes. Our approach is illustrated on relevant example models, and the performance of our implementations is assessed on a variable dimension large-scale model.

I have reviewed the paper and found that the results of the paper are looking interesting and mathematically correct. The novelty of the work is also good and the presentation is also nice.

In my opinion, the paper can be accepted for publication after considering the following minor revisions:

(1). Authors must justify the advantages of study.

(2). Authors must explain why the present study is more important compared to existing works in this direction?

(3). P6 L222-223: why did you write in Bold?

(4). Figures 3 and 5 are not clear need to fix the pixel etc.

(5).  . and , are missing at few places.

 

Based on the above remarks, I recommend acceptance of the paper for publication subject to the above-mentioned minor changes aimed at improving the quality of the article.

Author Response

See attached cover letter.

Author Response File: Author Response.pdf