++++++++++++++++++ FME2001: - Review reports for paper 14 +++++++++++++++++++++ - Dear author(s) : this file was extracted automatically from a very large - mailbox. In case you find any problem concerning mail encodings (or any - other kind of anomaly disturbing your understanding of the reviews) please - email any of the PC cochairs (pamela@research.att.com,jno@di.uminho.pt). ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PAPER NUMBER: 14 CATEGORY: 2 TITLE: Hierarchic Normal Forms for desynchronization AUTHOR(S): Jean-Pierre Talpin Albert Benveniste Benoit Caillaud Paul Le Guernic -------------------------------------------------------------------------------- 1. Briefly SUMMARIZE the paper (2-3 lines): The paper presents an approach to converting a synchronous design into an asynchronous design while guaranteeing that the distributed asynchronous version has the same behavior as the original synchronous system. Although the authors are careful to point out that their methodology will not apply universally to all embedded systems, they believe their approach could be useful in practice especially in concert with other approaches. The approach is illustrated on a simple Statecharts example that includes an arbiter, emitter and some counters. 2. RELEVANCE: Please provide a rating of the paper's relevance to the FME Symposium, using the scale: 0 = Out of scope 1 = Marginal interest 2 = Minority interest 3 = Majority interest 4 = Outstanding interest Numeric Rating: 2 Please comment your rating: It is a highly theoretical paper. 3. OVERALL RECOMMENDATION: Please provide a rating of the paper's acceptability, using the scale: 1 = Strong reject 2 = Weak reject 3 = Could go either way 4 = Weak accept 5 = Strong accept Numeric Rating: 4 NB: There should be a correlation between the two rates above. 4. CONFIDENCE LEVEL: Please provide a rating oof your expertise in the area addressed by the paper, using the scale: 1 = Know virtually nothing about this area 2 = Not too knowledgeable, but I know a bit 3 = Know a moderate amount, about average I'd say 4 = Not my main area of work, but I know a lot about it 5 = My area of work, I know it extremely well Numeric Rating: 2 NB: PC members are responsible for ensuring that 1 is not used here. 5. ORIGINALITY. What is NEW and SIGNIFICANT in the work reported here? Comment: The contribution is a detailed theory of desynchonization. The theory introduces the notion of endo-isochrony and utilizes a hierarchic normal form for synchronous transition systems. 6. How WORTHWILE is the goal of the authors? Comment: Perhaps this theory may form the basis for development tools for distributed systems one day. 7. How well is this goal EXPLAINED and JUSTIFIED? Comment: The authors explain the theoretical goals very well---the above speculation is my own. The goal is explained through use of the Statecharts example. This was an effective way to motivate the problem they were addressing. 8. TECHNICAL QUALITY. Are the technical parts (definitions, statements, specifications, proofs, algorithms, etc.) SOUND? Comment: Seems to be of high quality though it is beyond my capabilities to verify it. 9. APPLICABILITY. If the work is primarily theoretical or conceptual, are the implications in terms of applicability adequately justified? If the paper is about a new formal technique, are satisfactory arguments presented in favor of the new technique? If a methodology is proposed, is it sound? If experimental results are presented, is their relevance justified? Comment: The potential uses of their approach is not discussed in any detail at all. 10. PRESENTATION: Describe the QUALITY of the writing, including suggestions for changes where appropriate. Comment: Writing quality is very good. 11. Were there any formatting or mechanical problems with this paper?: no Are the figures and length acceptable?: yes Are the references correct?: yes 12. OTHER COMMENTS you believe would be useful to the author(s), including pointers to missing relevant work: I am concerned that the audience for this work is small. +++++++++++++++++++++ End of FME 2001 Paper Review Report ++++++++++++++++++++++ PAPER NUMBER: 14 CATEGORY: 2 TITLE: Hierarchic Normal Forms for desynchronization AUTHOR(S): Jean-Pierre Talpin Albert Benveniste Benoit Caillaud Paul Le Guernic -------------------------------------------------------------------------------- 1. Briefly SUMMARIZE the paper (2-3 lines): The paper presents a new data structure calle the hierarchic normal form for a transition relation applied to statecharts; it presents a way to obtain abstractions based on clocks. 2. RELEVANCE: Please provide a rating of the paper's relevance to the FME Symposium, using the scale: 0 = Out of scope 1 = Marginal interest 2 = Minority interest 3 = Majority interest 4 = Outstanding interest Numeric Rating: 3 Please comment your rating: The synchonous approach is a very large community which has demonstrated the usefulness of this approach. 3. OVERALL RECOMMENDATION: Please provide a rating of the paper's acceptability, using the scale: 1 = Strong reject 2 = Weak reject 3 = Could go either way 4 = Weak accept 5 = Strong accept Numeric Rating: 4 NB: There should be a correlation between the two rates above. 4. CONFIDENCE LEVEL: Please provide a rating oof your expertise in the area addressed by the paper, using the scale: 1 = Know virtually nothing about this area 2 = Not too knowledgeable, but I know a bit 3 = Know a moderate amount, about average I'd say 4 = Not my main area of work, but I know a lot about it 5 = My area of work, I know it extremely well Numeric Rating: 5 NB: PC members are responsible for ensuring that 1 is not used here. 5. ORIGINALITY. What is NEW and SIGNIFICANT in the work reported here? Comment: The paper contains old theorems proved by authors and it proposes a comparison between synchrony and asynchony; the technique used can also be seen as an abstraction with respect to clocks. And the works will have applications to the improvement of the analysis of statecharts in which hierachy is important. 6. How WORTHWILE is the goal of the authors? Comment: well 7. How well is this goal EXPLAINED and JUSTIFIED? Comment: well but there is no real proof 8. TECHNICAL QUALITY. Are the technical parts (definitions, statements, specifications, proofs, algorithms, etc.) SOUND? Comment: sound since theorems are prove elsewhere! 9. APPLICABILITY. If the work is primarily theoretical or conceptual, are the implications in terms of applicability adequately justified? If the paper is about a new formal technique, are satisfactory arguments presented in favor of the new technique? If a methodology is proposed, is it sound? If experimental results are presented, is their relevance justified? Comment: Probabaly useful for the verification of statecharts or synchrounous formalisms with pictures. 10. PRESENTATION: Describe the QUALITY of the writing, including suggestions for changes where appropriate. Comment: a good presentation 11. Were there any formatting or mechanical problems with this paper?: no Are the figures and length acceptable?: yes Are the references correct?: there are missing ones 12. OTHER COMMENTS you believe would be useful to the author(s), including pointers to missing relevant work: Your approach is very close to the refinement mapping an it allows one to state a relationship between two models by abstraction over clocks. I think that you should give more comparisons with the works of Abadi and Lamport. +++++++++++++++++++++ End of FME 2001 Paper Review Report ++++++++++++++++++++++ PAPER NUMBER: 14 CATEGORY: 2 TITLE: Hierarchic Normal Forms for desynchronization AUTHOR(S): Jean-Pierre Talpin Albert Benveniste Benoit Caillaud Paul Le Guernic -------------------------------------------------------------------------------- 1. Briefly SUMMARIZE the paper (2-3 lines): A data structure, called the `Hierarchic Normal Form' is defined for representing transition relations. HNFs can be used to derive sufficient conditions on an asynchronous execution so that it retains the properties of a synchronous execution of the same program. 2. RELEVANCE: Please provide a rating of the paper's relevance to the FME Symposium, using the scale: 0 = Out of scope 1 = Marginal interest 2 = Minority interest 3 = Majority interest 4 = Outstanding interest Numeric Rating: 2 Please comment your rating: The paper has some interesting ideas, but they are marred by a confusing presentation. The material is probably of interest to a minority of researchers in this area, but a better presentation would certainly increase the audience. 3. OVERALL RECOMMENDATION: Please provide a rating of the paper's acceptability, using the scale: 1 = Strong reject 2 = Weak reject 3 = Could go either way 4 = Weak accept 5 = Strong accept Numeric Rating: 3 NB: There should be a correlation between the two rates above. 4. CONFIDENCE LEVEL: Please provide a rating oof your expertise in the area addressed by the paper, using the scale: 1 = Know virtually nothing about this area 2 = Not too knowledgeable, but I know a bit 3 = Know a moderate amount, about average I'd say 4 = Not my main area of work, but I know a lot about it 5 = My area of work, I know it extremely well Numeric Rating: 3 NB: PC members are responsible for ensuring that 1 is not used here. 5. ORIGINALITY. What is NEW and SIGNIFICANT in the work reported here? Comment: The authors present the work as original, and I have no reason to dispute this claim. I find it difficult to gauge its significance, since no substantial examples of the use of the technique are presented. 6. How WORTHWILE is the goal of the authors? Comment: Providing techniques for building programs synchronously, and then desynchronizing them for efficient execution is a very worthwhile goal. 7. How well is this goal EXPLAINED and JUSTIFIED? Comment: The presentation of the material is obscure in places, and the examples and diagrams are poorly explained. 8. TECHNICAL QUALITY. Are the technical parts (definitions, statements, specifications, proofs, algorithms, etc.) SOUND? Comment: I can see no obvious deficiencies. 9. APPLICABILITY. If the work is primarily theoretical or conceptual, are the implications in terms of applicability adequately justified? If the paper is about a new formal technique, are satisfactory arguments presented in favor of the new technique? If a methodology is proposed, is it sound? If experimental results are presented, is their relevance justified? Comment: This work is still in the formative stages, so questions of applicability are probably premature. The overall goal, allowing automatic desynchronization of synchronous systems is definitely worthwhile. The final paragraph of the paper suggests that the technique is only one of a number of techniques that are applicable to the problem, and that this technique is not applicable in all cases. 10. PRESENTATION: Describe the QUALITY of the writing, including suggestions for changes where appropriate. Comment: The writing needs substantial improvement if this material is to be made accessible to a wider audience. The following are some of the major problems I noted. (A) After a couple of readings of the paper, I still have no real appreciation for what type of systems are endochronous, and which are isochronous. I do not properly understand the definition of the former, since it is unclear what it means to say that the presence or absence of a variable can be determined from the presence or absence, and the values, of a set of variables. (B) The convergence of the sequence used in the definition of endochrony appears to depend on the fact that the set of variables V is finite, but I could not find a statement of this anywhere. (C) The diagrams in section 2 need a better explanation. In particular, it took some effort on my part to understand the execution exhibited on the right of Figure 1. I do not understand what is being shown in the execution on the right of Figure 2. The sequence of events on the central line is not the same as that in Figure 1. Figure 3 repeats the statechart from Figure 2. This main effect of this was to cause me to carefully check that the two statecharts are, in fact, identical. I suggest only showing the statechart once. (D) I do not understand what the `local superstep' a_st_sp is, and how its use causes synchronization. My lack of understanding is complicated by the fact that Figure 4 shows this step as a message in the system, but, `for simplicity', the statechart is not amended to show the circumstances under which this message is generated. The lack of a key for the diagram on the right of Figure 4 means I was unable to determine where a_st_sp appears in the execution. (E) Some of the terminology is confusing. The term `clock' is used, without definition, on page 4. In the beginning of section 4 on page 6, the term `reactions' is used, but it is unclear how these differ from `transitions'; according to the paper, `a reaction consists of a transition of the STS', which suggests that the names are synonymous. (F) Figure 5, on page 13, fails to convey to me what is going on in the definition in equation (24). (G) I was rather lost by the end of the paper, but the claim on page 19, `In this way, the minimum number of additional boolean clocks is created', seems to require some justification. It is not apparent that the algorithm presented gives a minimum. (H) The writing reads like that of someone whose first language is other than English. This definitely hinders the effective communication of the ideas. 11. Were there any formatting or mechanical problems with this paper?: None that I noticed. Are the figures and length acceptable?: See comments above on the figures. Length is acceptable. Are the references correct?: I see no obvious defects. 12. OTHER COMMENTS you believe would be useful to the author(s), including pointers to missing relevant work: Minor typographical errors: Page 2: a component of the statechart is called 2_bit_# in the diagram, and 2_bit-counter in the text. Page 5: `initial transitions' should be `initial states'. Page 14: `shortage' should be `shorthand'. Page 19: `examplified' should be `exemplified'. +++++++++++++++++++++ End of FME 2001 Paper Review Report ++++++++++++++++++++++