Becker, M (Corresponding Author), Inst St Louis, 5 Rue Gen Cassagnou, F-68301 St Louis, France. Becker, Marvin; Seidl, Marina, Inst St Louis, 5 Rue Gen Cassagnou, F-68301 St Louis, France. De Vuyst, Tom, Univ Hertfordshire, Dept Engn & Technol, Hatfield AL10 9AB, Herts, England. Schulte, Miriam, Univ Stuttgart, Inst Parallel & Distributed Syst, Univ Str 38, D-70569 Stuttgart, Germany.