\begin{table}%t2
%\centering
\par
\caption{Model parameters.}
\small \begin{tabular}{lll}
\hline \hline
 General   &   Prescription    &  Parameter \\
\hline
 IMF    &   KTG1993    &            \\
 Mass limits   &   (0.1--100) \ms\              &            \\
 SFR                           &   $\alpha$$\Sigma_{\rm gas}^{1.5}(r_{{\rm eq}\odot}/r)$ &  $\alpha$  \\
 Stellar yields                &   vdHG97,WW95                &            \\
 Metallicity of infall gas     &   $Z_{f} = 0$                &            \\
 Infall timescale             &   $\tau(r) = b \ (r/r_{\rm d})$    &   $b$        \\
 Age of disk (Gyr)             &   13.5                       &            \\
\hline
Individual   &   Milky Way                  &   M~31         \\
\hline
 Scalelength $r_{\rm d}$ (kpc)     &   2.3                       &   5.5           \\
 Equivalent $r_{{\rm eq}\odot}$(kpc)  &   8.0                       &   19.0    \\
% Mass surface density at 10kpc &   $\Sigma_{10kpc}$ = 50 \ms\ pc$^{-2}$    \\
 Total disk mass ($10^{10}$\ms) &  5.0                        &   7.0           \\
 $V_{\rm rot}$(km~s$^{-1}$)                &  220                        &   226           \\
\hline  
\end{tabular} \\
\end{table}