1. Department of Polymer Science and Engineering; Kyungpook National University; 1370, Sankyuk-dong, Buk-ku Daegu 702-701 Korea
2. Gumi Electronics and Information Technology Research Institute, Gumi; Gyeongsangbuk-do 730-853 Korea
3. Daegu Technopark Nano Convergence Practical Application, Center; 891-5 Daecheon-dong Dalseo-ku, Daegu 704-801 Korea