1. School of Electrical and Electronic Engineering, USM Engineering Campus, Universiti Sains Malaysia, Penang, 14300 Malaysia,
2. School of Electrical and Electronic Engineering, USM Engineering Campus, Universiti Sains Malaysia, Penang, 14300 Malaysia
3. School of Electrical and Electronic Engineering, Northern Malaysia University College of Engineering, Perlis, 02600 Malaysia
4. School of Chemical Sciences, Universiti Sains Malaysia, Penang, 11800, Malaysia