[1] Korea Inst Sci & Technol, Elect Mat Res Ctr, 39-1 Hawolgok Dong, Seoul 136791, South Korea
[2] Virginia Tech, CEHMS, BMDL, Blacksburg, VA 24061 USA
[3] Daelim Univ Coll, Dept Digital Elect, 29 Imgoklo, Anyang 431715, Gyunggi Do, South Korea
[4] Korea Univ, KU KIST Grad Sch Converging Sci & Technol, Seoul 136701, South Korea