%0 Journal Article %T Regularization and error estimates for nonhomogeneous backward heat problems %A Duc Trong Dang %A Huy Tuan Nguyen %J Electronic Journal of Differential Equations %D 2006 %I Texas State University %X In this article, we study the inverse time problem for the non-homogeneous heat equation which is a severely ill-posed problem. We regularize this problem using the quasi-reversibility method and then obtain error estimates on the approximate solutions. Solutions are calculated by the contraction principle and shown in numerical experiments. We obtain also rates of convergence to the exact solution. %K Backward heat problem %K ill-posed problem %K contraction principle %K quasi-reversibility methods. %U http://ejde.math.txstate.edu/Volumes/2006/04/abstr.html