\begin{table}%t1
%\centering
\par
\caption{\label{tab_neighbor}Location information of pixels around the center of a magnetic element.}
 \begin{tabular}{lll}
            \hline
            \hline
            $(i-1, j-1)$ & $(i-1,j)$ & $(i-1, j+1)$ \\
            $(i, j-1)$ & $(i,j)$ & $(i, j+1)$ \\
            $(i+1,j-1)$ & $(i+1, j)$ & $(i+1, j+1)$ \\
            \hline
         \end{tabular}
\end{table}