1. Assistant Professor, Dept. of Civil Engineering, Yeungnam Univ., 214-1 Dae-Dong, Gyeongsan-Si, Gyeongsangbuk-Do, 712-749, Korea.
2. A. J. Clark Chair Professor, Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD, 20742-3021; Member, Polish Academy of Sciences Institute of Theoretical and Applied Informatics, Gliwice, Poland; Foreign Member, Russian Academy of Engineering, Moscow.