1. School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu 702-701, South Korea;
2. Department of Electronics Engineering, Sejong University, Seoul 143-747, South Korea;
3. Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea;
4. Department of Display Engineering, College of Engineering, Pukyong National University, Busan, Korea