1. Research Associate, Institute of Aerodynamics and Flow Technology, German Aerospace Center (DLR), 37073 Goettingen, Germany; presently, Research Institute for Optronics and Pattern Recognition (FGAN-FOM), Gutleuthausstrasse 1, 76275 Ettlingen, Germany.
2. Research Assistant, Institute for Hydromechanics, Univ. Karlsruhe, Karlsruhe, Germany and DICAT, Univ. Genova, Genova, Italy.
3. Professor and Director, Institute for Hydromechanics, Univ. Karlsruhe, Karlsruhe, Germany.