Abstract
For solving inverse boundary value problems, over-prescribed boundary values have been used. In the present study boundary values on the incompletely prescribed boundaries are estimated using the inside measurements. The inverse boundary value problem is treated for two-dimentional elastostatic body. Application of the boundary element method reduces this inverse boundary value problem to the solution of matrix equation. This matrix equation is severely ill-conditioned because of the ill-posedness of the problem. Regularization is therefore necessary to obtain a good solution of this matrix equation. A selection of the effective rank is necessary for solving inverse boundary value problem with the use of the singular value decomposition. The discrepancy principle that evaluates the discrepancy in observation equations and requires inverse analysis only is successfully applied to the selection of the effective rank. The effect of the effective rank on the estimation is disscussed.