“…Numerical simulations for anisotropic diffusion problems have been addressed by a lot of researchers and engineers; see the review in [12]. Methods used today include finite volume method [20,21,24], finite difference method [8], mimetic finite difference method [14], discontinuous Galerkin method [1,7], finite element method [10,13,15,19] and so on. These methods are usually efficient for a selected range of ǫ but loss convergence when ǫ ≪ h (h is the mesh size).…”