Affiliation: | 2. Centre d''Etudes et Recherches C.E.M. 93, Le Bourget, France. This work was done when the author was with Laboratoire d''Automatique de Grenoble and Direction des Recherches ALSTHOM, Grenoble, France;3. Laboratoire d''Automatique de Grenoble, Institut National Polytechnique de Grenoble, B.P. 15, 38040 Grenoble CEDEX France |