J. M. Joung
Electrical material lab., Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute
S. M. Baek
Electrical material lab., Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute
S. H. Kim
Electrical material lab., Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute