Southeast Asian Journal of Sciences —————————————————————— Volume 1 • Number 2 • December 2012 Honorary Editors Le Cong Co Duy Tan University, Danang, Vietnam Nguyen Manh Hung Nguyen Tat Thanh Univ., Ho Chi Minh city, Vietnam Sauwanee Thairungroj Univ. of the Thai Ch. of Commerce, Bangkok, Thailand Chief Editor Nguyen Van Sanh Mahidol University, Bangkok, Thailand Deputy Chief Editors Soon-Geul Lee Kyung Hee University, Suwon, South Korea Le Tran Ngoan Hanoi Medical University, Hanoi, Vietnam Tran Dinh Que Hanoi University of Telecommunication, Vietnam Tran Van Sung Vietnam Academy of Natural Sciences, Hanoi, Vietnam Managing Editors Nguyen Van Luong Nguyen Tat Thanh University, Ho Chi Minh city, Vietnam Le Nguyen Bao Duy Tan University, Danang, Vietnam Nittiya Pabhapote Uni. of the Thai C. of Commerce, Bangkok, Thailand sponsored by http://science.utcc.ac.th/sajs ISSN 2286-7724