1. Department of Electronics Engineering, College of Electronics & Information Engineering, Sejong University, Seoul, 143-747, Korea, Busan, 608-737, Korea;
2. School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu 702-701, Korea;
3. Department of Computer Engineering, College of Engineering, Pukyong National University, Busan, 48513, Korea;
4. Department of Display Engineering, College of Engineering, Pukyong National University, Busan, 608-737, Korea