This manuscript was originally uploaded to arXiv in 2007 (arXiv:0708.3289v1). In the current version, we expand the Introduction and the list of references which are related to the results of this paper after 2007. In this work we establish log type stability estimates for the inverse potential and conductivity problems with partial Dirichlet-to-Neumann map, where the Dirichlet data is homogeneous on the inaccessible part. The proof is based on the uniqueness result of the inverse boundary value problem in Isakov’s work [17].