L-Infinity approximation of a parabolic system regarded as a delay system
Résumé
We present an approach to the problem of finding a, L(infinity) approximant of the infinite-dimensional system describing the diffusion of heat in a wall. We show that this system can be regarded as a de ay system with Laplace variable square-root s. We are able to get results, established in Zwart et al. (1988), about partial fraction expansion for delay systems, achieved by some adjustment to the specificities of our particular case. The determination of an L(infinity) approximant is realised in two steps, using the optimal Hankel-norm approximation.