1. National University of Malaysia, Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Bangi, Malaysia
2. National University of Malaysia, Institute of Microengineering and Nanoelectronics, Bangi, MalaysiacHarvard University, School of Engineering and Applied Science, John A. Paulson, Cambridge, Massachusetts, United States
3. Al-Hussein Bin Talal University, College of Science, Department of Physics, Ma’an, Jordan
4. National University of Malaysia, Faculty of Science and Technology, Bangi, Malaysia