1. Department of Electrical Engineering; University of Malaya; Kuala Lumpur 50603 Malaysia
2. Department of Materials, Manufacturing and Industrial Engineering; University Teknologi Malaysia; Johor Bahru 81310 Malaysia
3. School of Electrical and Electronics Engineering; University Sains Malaysia; Penang 14300 Malaysia
4. School of Materials and Mineral Resources Engineering; University Sains Malaysia; Penang 14300 Malaysia