الخلاصة:
The problems of identiÖcation consist to Önd the causes of a phenomenon on starting from
an observation; the resolution of this problem is doing by an experimental measurements. In
this work, we aim to estimate the shape of an unknown part of the boundary of a geometric
domain. The technique used for this purpose is the sentinel method introduced by J. L. Lions.
It will be based on the observation of the solution of a di§usion problem on the known part
of the boundary and to build a family of functions which allows giving information on the
unknown part.