1. Department of Civil Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
2. Department of Environmental Science and Technology, University of Maryland, College Park, MD 20742, USA
3. Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
4. Faculty of Science and Engineering, University of Nottingham Malaysia, Semenyih 43500, Malaysia