1. Professor, College of Engineering, Ocean Univ. of China, Qingdao, China. E-mail: huajun@ouc.edu.cn
2. Visiting Scholar, Dept. of Ocean Development Engineering, Korea Maritime Univ., Busan, Korea.
3. Professor, Dept. of Ocean Engineering, Univ. of Rhode Island, Narragansett, RI 02882-1197. E-mail: hu@oce.uri.edu