1. Department of Nano Fusion Technology, Pusan National University, Miryang, Korea
2. Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, Korea
3. Department of Materials Science & Engineering, University of California, Los Angeles, California 90095-1595
4. MCLAB Company Ltd., Pusan National University, Miryang, Korea
5. Department of Physics, Pusan National University, Busan, Korea
6. Division of R&D, National Fusion Research Institute, Daejon, Korea