1Department of Creative IT Engineering, Pohang University of Science and Technology, Pohang, Korea
2Department of Nanobio Material and Electronic, Gwangju Institute of Science and Technology, Gwangju, Korea
3IBM-Research Almaden, San Jose, CA, USA
4Department of Material Science and Engineering, Pohang University of Science and Technology, Pohang, Korea
5Department of Electrical Engineering, Pohang University of Science and Technology, Pohang, Korea