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\date{\today}   

%\signature{Abdo Y. Alfakih }

%\begin{letter}{ 

%\opening{Dear Melissa,}

%\closing{Best regards,}


%\end{letter}

\section*{}
\begin{center}
{ \large  Referee's report on \\ ``Theory of semidefinite
programming for sensor network localization" \\ by \\ 
A. M-C So and Y. Ye } 
\end{center}

\flushleft

This paper presents a semidefinite programming model for
sensor network localizations. This problem can be thought
of as a special case of the graph realization problem where
the coordinates of a subset of the nodes are known. The
paper also discusses some related problems in distance
geometry.  

The sensor network localization problem is an important problem
which has received a great deal of attention recently. The 
semidefinite approach to this problem is quite elegant and 
promising. The results obtained in this paper are new and
interesting. The paper is well written and
easy to read. Furthermore, the references are comprehensive. 

Thus we recommend that this paper be accepted for publication. 
We would like to add one comment. 
The SDP problems in (3) and (4) seem complicated due to the notation
used. We believe that these two problems might be simplified by
using more appropriate notation.

Finally there is a typo on page 4. Replace well-known by
well known in the line before (2).   
  
   
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