X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/LiCO.git/blobdiff_plain/f728a52ec5b5d3a0b90f03b90777f454b88b21be..b8690edb619fdecf1e6a382474c17811c2653c4f:/PeCO-EO/reponse.tex

diff --git a/PeCO-EO/reponse.tex b/PeCO-EO/reponse.tex
index 1fb3f07..f35e844 100644
--- a/PeCO-EO/reponse.tex
+++ b/PeCO-EO/reponse.tex
@@ -19,7 +19,7 @@
 \today
 \end{flushright}%
 
-\vspace{-0.5cm}\hspace{-2cm}FEMTO-ST Institute, UMR 6714 CNRS
+\vspace{-0.5cm}\hspace{-2cm}FEMTO-ST Institute, UMR 6174 CNRS
 
 \hspace{-2cm}University Bourgogne Franche-Comt\'e
 
@@ -33,7 +33,7 @@ Detailed changes and addressed issues in the revision of the article
 ``Perimeter-based Coverage Optimization \\
 to Improve Lifetime in Wireless Sensor Networks''\\
 
-by Ali Kadhum Idrees, Karine Deschinkel, Michel Salomon, and Raph\"ael Couturier
+by Ali Kadhum Idrees, Karine Deschinkel, Michel Salomon and Raph\"ael Couturier
 
 \medskip
 
@@ -86,9 +86,9 @@ application of these methods for the coverage scheduling problem.\\
 assumption made on the selection criteria for the leader seems too vague.  \\
 
 \textcolor{blue}{\textbf{\textsc{Answer:} The selection  criteria for the leader
-    inside each subregion  is explained page~9, at  the end of Section~3.3
-    After the information  exchange among  the sensor nodes  in the  subregion, each
-    node will have all the information needed to decide if it will be the leader or
+    inside each subregion is explained page~9, at the end of Section~3.3.  After
+    the information exchange among the sensor  nodes in the subregion, each node
+    will have all the  information needed to decide if it will  be the leader or
     not. The decision is based on selecting  the sensor node that has the larger
     number of one-hop neighbors. If this value is the same for many sensors, the
     node that has the largest remaining energy will be selected as a leader.  If
@@ -103,7 +103,7 @@ cooperate and make these decisions was not discussed.\\
 
 \textcolor{blue}{\textbf{\textsc{Answer:}  The   communication  and  information
     sharing required to  cooperate and make these decisions is  discussed at the
-    end of page  8.  Position coordinates, remaining energy, sensor  node ID and
+    end of page 8.  Position coordinates,  remaining energy, sensor node ID, and
     number of one-hop neighbors are exchanged.}}\\
 
 \noindent  {\bf  4.}  The  definitions  of  the undercoverage  and  overcoverage
@@ -140,22 +140,22 @@ results showing how the algorithm performs with different alphas and betas.\\
     200~sensor nodes.  It explains the  value chosen for the simulation settings
     in Table~2. \\ \indent The choice of alpha and beta should be made according
     to the  needs of the  application. Alpha should  be large enough  to prevent
-    undercoverage and  thus to  reach the highest  possible coverage  ratio.  Beta
-    should be enough large to prevent  overcoverage and thus to activate a minimum
-    number of sensors.  The values of  $\alpha_{i}^{j}$ can be identical for all
-    coverage  intervals $i$  of one  sensor  $j$ in  order to  express that  the
-    perimeter of each  sensor should be uniformly  covered, but $\alpha_{i}^{j}$
-    values can  be differentiated between  sensors to  force some regions  to be
-    better covered  than others. The choice  of $\beta \gg \alpha$  prevents the
-    overcoverage, and so limit the activation  of a large number of sensors, but
-    as $\alpha$  is low,  some areas  may be poorly  covered. This  explains the
-    results obtained for $Lifetime_{50}$ with $\beta \gg \alpha$: a large number
-    of periods with  low coverage ratio.  With $\alpha \gg  \beta$, we favor the
-    coverage even  if some areas may  be overcovered, so a high  coverage ratio is
-    reached, but a  large number of sensors are activated  to achieve this goal.
-    Therefore  the network  lifetime  is   reduced.   The  choice  $\alpha=0.6$  and
-    $\beta=0.4$  seems  to achieve  the  best  compromise between  lifetime  and
-    coverage ratio.}}\\
+    undercoverage and thus  to reach the highest possible  coverage ratio.  Beta
+    should  be large  enough  to prevent  overcoverage and  thus  to activate  a
+    minimum number of sensors.  The  values of $\alpha_{i}^{j}$ can be identical
+    for all coverage  intervals $i$ of one  sensor $j$ in order  to express that
+    the   perimeter  of   each   sensor  should   be   uniformly  covered,   but
+    $\alpha_{i}^{j}$ values can be differentiated  between sensors to force some
+    regions to be  better covered than others. The choice  of $\beta \gg \alpha$
+    prevents the overcoverage, and so limit  the activation of a large number of
+    sensors, but  as $\alpha$  is low,  some areas may  be poorly  covered. This
+    explains the results obtained for $Lifetime_{50}$ with $\beta \gg \alpha$: a
+    large number of  periods with low coverage ratio.  With  $\alpha \gg \beta$,
+    we favor  the coverage  even if  some areas  may be  overcovered, so  a high
+    coverage ratio  is reached, but a  large number of sensors  are activated to
+    achieve this goal.   Therefore the network lifetime is  reduced.  The choice
+    $\alpha=0.6$ and  $\beta=0.4$ seems to  achieve the best  compromise between
+    lifetime and coverage ratio.}}\\
 
 \noindent {\bf  6.} The  authors have  performed a  thorough review  of existing
 coverage  methodologies.  However,  the clarity  in the  literature review  is a
@@ -166,10 +166,12 @@ suggest using the journals template to adjust them for overall consistency.\\
 \textcolor{blue}{\textbf{\textsc{Answer:} References have been carefully checked
     and seem to be consistent with the journal template. In Section~2, ``Related
     literature'',  we refer  to papers  dealing  with coverage  and lifetime  in
-    WSN. Each  paragraph of this Section  discusses the literature related  to a
+    WSN. Each  paragraph of this section  discusses the literature related  to a
     particular aspect of the problem : 1. types of coverage, 2. types of scheme,
     3. centralized versus distributed protocols,  4. optimization method. At the
-    end of each paragraph we position our approach. We have also added a last paragraph about our previous work on DilCO protocol to explain the difference with PeCO. }}\\
+    end of each  paragraph we position our  approach. We have also  added a last
+    paragraph  about  our  previous  work  on  DiLCO  protocol  to  explain  the
+    difference with PeCO. }}\\
 
 \noindent {\bf 7.} The methodology is implemented in OMNeT++ (network simulator)
 and tested  against 2 existing algorithms  and a previously developed  method by
@@ -208,12 +210,12 @@ coverage ratio. \\
     every Section is indented in the new version. }}\\
 
 \noindent  {\ding{90} You  seem to  be writing  in the  first person.  I suggest
-  rewriting sentences that include âweâ âourâ or âIâ in the third person. (There
+  rewriting sentences that include ``we'' ``our'' or ``I'' in the third person. (There
   are too many instances to list them  all. They are easily found using the find
   tool.)  }  \\
 
 \textcolor{blue}{\textbf{\textsc{Answer:} It  is very  common to  find sentences
-    with "we"  and "our" in  scientific papers to explain  the work made  by the
+    with ``we''  and ``our'' in  scientific papers to explain  the work made  by the
     authors. Nevertheless  we agree with  the reviewer and we  reformulated some
     sentences in the paper to avoid too many uses of the first person. }}\\
 
@@ -224,19 +226,19 @@ coverage ratio. \\
 
 \noindent {\ding{90} Add an âandâ after the comma on page 3 line 34.}  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90} âmodel asâ instead of âThanâ on page 10 line 12.}  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90} âno longerâ instead of âno moreâ on page 10 line 31.}  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90} âin the active stateâ add the on page 10 line 34. }  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent  {  \ding{90}  Lots  of  English and  grammar  mistakes.  I  recommend
   rereading the paper line by line and  adjusting the sentences that do not make
@@ -279,16 +281,16 @@ how should this common duration should be chosen?\\
     between  any pairs  of sensors  inside  a subregion  is less  than or  equal
     to~3. Concerning the choice of the sensing period duration, it is correlated
     with the types of applications, with the amount of initial energy in sensors
-    batteries and also with the duration of the exchange phase. All applications
-    do  not  have  the  same  Quality of  Service  requirements.   In  our  case,
-    information exchange is  executed every hour, but the length  of the sensing
-    period could  be reduced and  adapted dynamically. On  the one hand,  a small
-    sensing  period would  allow  the network to  be more  reliable  but  would have  higher
-    communication costs.   On the other hand,  the choice of a  long duration may
-    cause problems in case of nodes failure during the sensing period.
-    Several  explanations on  these points  are given  throughout the  paper. In
-    particular,  we discuss  the number  of subregions  in Section  5.2 and  the
-    sensing duration in the second paragraph of Section 5.1.}}\\
+    batteries,  and  also   with  the  duration  of  the   exchange  phase.  All
+    applications do not  have the same Quality of Service  requirements.  In our
+    case, information  exchange is executed  every hour,  but the length  of the
+    sensing period could be reduced and  adapted dynamically. On the one hand, a
+    small sensing period  would allow the network to be  more reliable but would
+    have higher  communication costs.  On the  other hand, the choice  of a long
+    duration may  cause problems  in case  of nodes  failure during  the sensing
+    period.   Several explanations  on  these points  are  given throughout  the
+    paper. In particular, we discuss the number of subregions in Section 5.2 and
+    the sensing duration in the second paragraph of Section 5.1.}}\\
 
 \noindent {\bf  2.}Page 9,  Section 4, is  the Perimeter-based  coverage problem
 NP-hard? This  question is important for  justifying the use of  a Mixed Integer
@@ -296,13 +298,13 @@ Linear Programming model.\\
 
 \textcolor{blue}{\textbf{\textsc{Answer:}  The   perimeter  scheduling  coverage
     problem is  NP-hard in  general, it  has been proved  in the  paper entitled
-    "Perimeter  Coverage Scheduling  in Wireless  Sensor Networks  Using Sensors
-    with a  Single Continuous Cover Range"  from Ka-Shun Hung and  King-Shan Lui
+    ``Perimeter Coverage  Scheduling in  Wireless Sensor Networks  Using Sensors
+    with a Single  Continuous Cover Range'' from Ka-Shun Hung  and King-Shan Lui
     (EURASIP Journal on Wireless Communications and Networking 2010, 2010:926075
     doi:10.1155/2010/926075). In this  paper, authors study the  coverage of the
     perimeter of  a large object  requiring to be  monitored. In our  study, the
     large object  to be monitored  is the sensor  itself (or more  precisely its
-    sensing  area).  This  point  has  been  highlighted  at  the  beginning  of
+    sensing  area).   This  point  has  been highlighted  at  the  beginning  of
     Section~4.}}\\
 
 \noindent {\bf 3.}  Page 9, the major  problem with the present paper  is, in my
@@ -318,10 +320,11 @@ performance metrics  list given in Section  5.1 is exhaustive, then  the authors
 should mention at the beginning of the  paper what are the aims of the protocol,
 and explain how the protocol is built to optimize these objectives.  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:}  Right.   The   mixed  Integer  Linear
+\textcolor{blue}{\textbf{\textsc{Answer:}  Right.   The   Mixed  Integer  Linear
     Program adresses  a multiobjective  problem, where the  goal is  to minimize
-    overcoverage and  undercoverage for each  coverage interval of a  sensor. To the best of our knowledge, representing  the objective function  as a weighted  sum of
-    criteria  to  be  minimized  in  case of  multicriteria  optimization  is  a
+    overcoverage and  undercoverage for each  coverage interval of a  sensor. To
+    the best of our knowledge, representing the objective function as a weighted
+    sum of criteria  to be minimized in case of  multicriteria optimization is a
     classical method.   In Section 5, the  comparison of protocols with  a large
     variety of performance metrics allows  to select the most appropriate method
     according to the QoS requirement of the application.}}\\
@@ -376,25 +379,24 @@ constraints.
 Total number & S & I & GLPK IP & GLPK LP & nodes&CPLEX\\
 of nodes &&&&relaxation &B\&B tree &\\
 \hline
-100 & 6.25& 5&0.2 MB & 0.2 Mb &1 &  64 kB\\
+100 & 6.25& 5&0.2 MB & 0.2 MB &1 &  64 KB\\
 \hline
-200 & 12.5& 11&1.7 MB & 1.6 Mb &1 & 281 kB\\
+200 & 12.5& 11&1.7 MB & 1.6 MB &1 & 281 KB\\
 \hline
-300 &18.5 & 17&3.6 MB & 3.5 Mb & 3 &644 kB\\
+300 &18.5 & 17&3.6 MB & 3.5 MB & 3 &644 KB\\
 \hline
 \end{tabular}
-\medskip  \\
-It  is noteworthy  that the  difference  of memory  used with  GLPK between  the
-resolution of  the IP  and its  LP-relaxation is  very weak  (not more  than 0.1
-MB). The size of  the branch and bound tree does not exceed  3 nodes. This result
-leads one to  believe that the memory use with  CPLEX\textregistered for solving
-the IP would be very close to that  for the LP-relaxation, that is to say around
-100 Kb for a subregion containing $S=10$ sensors.  Moreover the IP seems to have
-some specifities that encourage us to develop our own solver (coefficents matrix
-is  very sparse)  or  to use  an  existing heuristic  to  find good  approximate
-solutions (Reference : ``A feasibility pump heuristic  for general mixed-integer
-problems",  Livio  Bertacco  and  Matteo Fischetti  and  Andrea  Lodi,  Discrete
-Optimization, issn 1572-5286).
+\medskip  \\ It  is noteworthy  that  the difference  of memory  used with  GLPK
+between the resolution  of the IP and  its LP-relaxation is very  weak (not more
+than  0.1  MB). The  size  of  the  branch and  bound  tree  does not  exceed  3
+nodes.  This   result  leads   one  to   believe  that   the  memory   use  with
+CPLEX\textregistered for  solving the  IP would  be very close  to that  for the
+LP-relaxation, that is to say less than 300 KB for a subregion containing $S=12$
+sensors.  Moreover  the IP seems to  have some specifities that  encourage us to
+develop our own solver (coefficents matrix is very sparse) or to use an existing
+heuristic to find  good approximate solutions (Reference :  ``A feasibility pump
+heuristic  for  general  mixed-integer  problems",  Livio  Bertacco  and  Matteo
+Fischetti and Andrea Lodi, Discrete Optimization, issn 1572-5286).
 \item  the subdivision  of the  region of  interest. To  make the  resolution of
   integer programming tractable by a leader  sensor, we need to limit the number
   of nodes  in each subregion  (the number of  variables and constraints  of the
@@ -448,36 +450,36 @@ A discussion about memory consumption has been added in Section 5.2}}
 \noindent  {\ding{90} Page  5, lines  34 and  37, replace  [0, $2\pi$]  with [0,
     $2\pi$) } \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90} Page 5, line 36 and  43, replace ``figure 2" with ``Figure 2"
 } \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90}  Page 5, line 50, replace ``section 4" with ``Section 4" }  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90}   Page 5, line 51, replace ``figure 3" with ``Figure 3"}  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90}  Page 7, line 20 ``regular homogeneous subregions" is too vague. }  \\
 
 \textcolor{blue}{\textbf{\textsc{Answer:} As  mentioned in the  previous remark,
     the spatial subdivision  was not clearly explained in the  paper. We added a
     discussion about  this question in  the article. Thank you  for highlighting
-    it. }}.\\
+    it. }}\\
 
 \noindent {\ding{90} Page 7, line 24, replace ``figure 4" with ``Figure 4"}  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 
 \noindent {\ding{90}  Page 7, line 47, replace ``Five status" with ``Five statuses" }  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90} Page 9, the constraints of the Mixed Integer Linear Program
   (2)  are  not  numbered.  There  are two  inequalities  for  overcoverage  and
@@ -500,7 +502,7 @@ A discussion about memory consumption has been added in Section 5.2}}
   connected". In order to assess this,  the communication range should be known,
   but it is not given in Table 2. }  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed}}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent  {\ding{90} Page  10, line  53,  the ``Coverage  ratio" definition  is
   provided for a given period p? Then in the formula on top of page 11, N is set
@@ -516,12 +518,12 @@ A discussion about memory consumption has been added in Section 5.2}}
 \noindent {\ding{90}  Page 11,  line 17  in the  formula of  ASR, |S|  should be
   replaced with J (where J is defined page 4 line 16). }  \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 \noindent {\ding{90} Page 13, line 41 and 43, replace ``figure 8" with ``Figure 8"
 } \\
 
-\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed }}.\\
+\textcolor{blue}{\textbf{\textsc{Answer:} Right, fixed.}}\\
 
 We are very grateful to the  reviewers who, by their recommendations, allowed us
 to improve the quality of our article.
