From c882850ec6da71a9df727591d68e24b4319c7fdd Mon Sep 17 00:00:00 2001 From: Karine Deschinkel Date: Mon, 24 Aug 2015 15:58:31 +0200 Subject: [PATCH] ok --- reponse.tex | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/reponse.tex b/reponse.tex index 4c48b6f..654a1d1 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 -- 2.39.5