Youngwoo Lee1, Donghoon Shin1 and Chung Choo Chung2∗
1Department of Electrical Engineering, Hanyang University, Seoul 133-791, Korea
(Tel: +82-2-2220-4308; E-mail: stork@hanyang.ac.kr (Y. Lee), shin211@hanyang.ac.kr (D. Shin))
2Division of Electrical and Biomedical Engineering, Hanyang University, Seoul, Korea
(Tel: +82-2-2220-1724, e-mail: cchung@hanyang.ac.kr)