1. a Department of Civil Engineering , Pukyong National University , Yongdang-Dong, Nam-Gu , Busan , Korea
2. b Hyorim Industries Inc. , Yatab-Dong, Seongnam city , Kyonggi-Do , Korea
3. c Water Business Group , Doosan Heavy Industries & Construction , Changwon , Korea
4. d Department of Environmental Engineering , Pukyong National University , Daeyeon-Dong, Nam-Gu , Busan , Korea Phone: Fax: