X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/JournalMultiPeriods.git/blobdiff_plain/876bc669165cfe7f2667787b7f58b59b77173cb5..6a0a093a654ceb1379ce0aa8439c1650c04f9929:/reponse.tex diff --git a/reponse.tex b/reponse.tex index 4c48b6f..f9381c8 100644 --- a/reponse.tex +++ b/reponse.tex @@ -97,7 +97,8 @@ two-phase approach where breach is minimized first, and then overcoverage is minimized would probably make more sense. \\ -\textcolor{blue}{\textbf{\textsc{Answer:} As mentioned in the paper the integer program is based on the model proposed by () with some modifications. Their initial approach consisted in first finding the maximum coverage obtainable from available sensors to then use this information as input to the problem of minimizing the overcoverage. But this two-steps approach is time consuming. The originality of the model is to solve both objectives in a parallel fashion. Nevertheless the weights }}\\ +\textcolor{blue}{\textbf{\textsc{Answer:} As mentioned in the paper the integer program is based on the model proposed by F. Pedraza and A. L. Medaglia and A. Garcia ("Efficient coverage algorithms for wireless sensor networks") with some modifications. Their initial approach consisted in first finding the maximum coverage obtainable from available sensors to then use this information as input to the problem of minimizing the overcoverage. But this two-steps approach is time consuming. The originality of the model is to solve both objectives in a parallel fashion. Nevertheless the weights $W_\theta$ and $W_U$ must be properly chosen so as to guarantee that the maximum number of points are covered during each round. By choosing $W_{U}$ very +large compared to $W_{\theta}$, the coverage of a maximum of primary points is ensured. Then for a same number of covered points, solution with a minimal number of active sensors is preferred. }}\\ @@ -108,7 +109,8 @@ the WSN. The authors are referred to "alpha-coverage to extend network lifetime on wireless sensor networks", Optim. Lett. 7, No. 1, 157-172 (2013) by Gentilli et al to enforce a constraint on the minimum coverage of each point. \\ -\textcolor{blue}{\textbf{\textsc{Answer:} }}\\ +\textcolor{blue}{\textbf{\textsc{Answer:} As previously explained, the model with the appropriate weights ensures that a maximum number of points are covered for the set of still alive sensors. The coverage is measured through the performance metrics "coverage ratio". The coverage ratio remains around 100\% as long as possible (as long as there are enough alive sensors to cover all primary points) and then decreases. The problem introduced in "alpha-coverage to extend network lifetime +on wireless sensor networks" by Gentilli is quite different. In this problem, the coverage ratio is fixed to a predetermined value ($\alpha$) and the amount of time during which the network can satisfy a target coverage greater than $\alpha$ is maximized. }}\\ \noindent {\bf 4.} Page 13 @@ -118,7 +120,7 @@ Computing the average energy consumption per unit of time over the network lifetime would be better, as it is independent from the number and duration of rounds. \\ -\textcolor{blue}{\textbf{\textsc{Answer :} }} +\textcolor{blue}{\textbf{\textsc{Answer :} Yes, you are right. It is possible to obtain the average energy consumption per unit of time by dividing the criterion defined in section .... by the round duration.}} @@ -129,9 +131,10 @@ Alternatively, the authors may remove some versions of MuDiLCO if they do not bring any valuable insight. \\ -\textcolor{blue}{\textbf{\textsc{Answer :} }} +\textcolor{blue}{\textbf{\textsc{Answer :} Right. We have completely re-written section 5 to highlight the most significant results. }} +\bigskip \noindent {\bf 6.} Page 19 (most major point) The authors state that solving the Mixed Integer Linear Program is time-consuming, and use this point for explaining why MuDiLCO-7 is not as @@ -143,7 +146,8 @@ is very likely to save time and energy, and to improve the results of MuDiLCO-7 in particular. \\ -\textcolor{blue}{\textbf{\textsc{Answer :} }} +\textcolor{blue}{\textbf{\textsc{Answer :} Your remark is very interesting. We have observed that the optimal solution of the integer program is often obtained after the exploration of very few nodes of the Branch-and-Bound-tree. Therefore we conducted new simulations by applying your idea. That is to say we have stopped the resolution of the Branch-and-Bound method after a time threshold empirically defined and we retain the best feasible +solution found by the solver. This approach allows to improve significantly the results with multirounds, especially for MuDiLCO-7.}} \bigskip @@ -160,7 +164,7 @@ follows" should mention the content of Section 5. } \\ The sentence "the centralized approaches usually suffer from the scalability problem, making them less competitive as the network size increase" should probably be tempered: heuristics and metaheuristics can handle very large and -centralized problems (even if exact approaches can't), and these approaches are +centralized problems (even if exact approaches can't), and these approaches areempirically very popular in WSN. } \\ \textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}\\ @@ -170,7 +174,7 @@ very popular in WSN. } \\ study not presented here". The authors should provide at least one reference about the aforementioned study. } \\ -\textcolor{blue}{\textbf{\textsc{Answer:} }}\\ +\textcolor{blue}{\textbf{\textsc{Answer:} Right. We have included a section (section ...) dedicated to the choice and the number of primary points. }}\\ \noindent {\ding{90} Page 6, Figure 1: All rounds seem to have the same duration. This should be stated explicitly, and