摘要

We solve an overspecified as well as underspecified inverse Cauchy problems of the modified Helmholtz equation in an arbitrary 3D-bounded domain with a smooth boundary using a multiple/scale/direction Trefftz method (MSDTM), of which the directions are uniformly distributed on S-1, and the scales are determined a priori by the collocation points on boundary to satisfy the specified boundary conditions. The three-dimensional numerical examples confirm the efficiency of theMSDTM. Although under a large noise up to 30%, the solutions of inverse Cauchy problems are quite accurate. More importantly, the present method converges very fast and saves much CPU time.