1. Ph.D. Student, Div. of Marine Engineering, Dept. of Naval Architecture and Marine Engineering, National Technical Univ. of Athens, Athens 15773, Greece.
2. General Manager, Global Testing, Winterthur Gas & Diesel Ltd., Schützenstrasse 1-3, Winterthur 8401, Switzerland.
3. General Manager, Technology Development, Winterthur Gas & Diesel Ltd., Schützenstrasse 1-3, Winterthur 8401, Switzerland.
4. Professor, Div. of Marine Engineering, Dept. of Naval Architecture and Marine Engineering, National Technical Univ. of Athens, Athens 15773, Greece (corresponding author).