1. Department
of Electrical and Biological Physics, Kwangwoon University, 447-1 Wolgye-Dong, Nowon-Gu, Seoul 139-701, Republic of Korea
2. Convergence
Plasma Research Center, National Fusion Research Institute, 113
Gwahangno, Yuseong-Gu, Daejeon 305-333, Republic of Korea
3. Wintech, Fifth Floor, Daewoo Building, Bangi-Dong, Songpa-Gu, Seoul 138-827, Republic of Korea