  We study the initial boundary value problem for one-dimensional
Kuramoto-Sivashinsky equation with nonhomogeneous boundary conditions. Through
the analysis of the boundary integral operator, and applying the known results
on the Cauchy problem, we obtain both the local well-posedness and the global
well-posedness for the nonhomogeneous initial boundary value problem. It is
shown that the Kuramoto-Sivashinsky equation is well-posed in Sobolev space
$C([0,T]; H^s (R^+)) \bigcap L^2(0,T; H^{s+2}(R^+))$ for $s>-2$.
