THE COEFFICIENT CONTROL PROBLEM AND THE EXTENDED DERIVATIVE OVER A CONVEX SET

摘要

The coefficient control problems are of theoretical and practical interest. They can be obtained by reduction of the coefficient inverse problems of mathematical physics (for example, [1]) and the domain control problems [2]-[4]. The complexity of the coefficient control problems is caused, in many respects, by their possible unsolvability ([5]; [6], pp. 47-48; [7]). Though the coefficient control problems for the elliptic type equations are studied in many papers (for example, [8]-[16]), they are not thoroughly investigated within the general extremum theory, because of the peculiarity of these problems.