1. School of Science and Technology, Middlesex University, London NW4 4BT, UK
2. Strategic Advanced Research (StAR), Mathematical Modeling Lab, MIMOS Berhad, Technology Park Malaysia, Kuala Lumpur, Malaysia
3. Department of Electrical and Electronic Engineering, Xi’an Jiaotong-Liverpool University, No. 111 Ren’ai Road, HET, SIP, Suzhou, Jiangsu 215123, China