  $D^0-\bar{D}^0$ mixing leads to the mass and width differences in the mass
eigenstates of $D^0$ and $\bar{D}^0$ mesons (measured by parameters $x^{~}_D$
and $y^{~}_D$ respectively), but their magnitudes cannot be reliably predicted
by the standard model. We show that it is possible to separately determine
$x^{~}_D$ and $y^{~}_D$ through {\it time-integrated} measurements of the
dilepton events of coherent $D^0\bar{D}^0$ decays on the $\psi(4.14)$ resonance
at a $\tau$-charm factory.
