Communication to : Proceedings of the international symposium TURBOMAT : 137-142, Bonn (Allemagne), June 19, 2002SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2002 n.107 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc