1. IT Nano Electronic Device Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-749, Republic of Korea
2. Electrical Engineering, Changwon National University, 20 Changwondaehak-ro, Uichang-gu, Changwon, Gyeongnam 51140, Republic of Korea
3. Department of Smart Electric, Korea Polytechnic, 23 Yeomjeon-ro, 333 Beon-gil, Nam-gu, Incheon 22121, Republic of Korea
4. College of Information Science and Technology, Donghua University, 2999 North Renmin Road, Songjiang District, Shanghai 201620, China