1. Department of Polymer & Textile Engineering, Hanyang University, Haengdang-dong, Sungdong-gu, Seoul 133-791, Korea
2. Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606, Japan
3. Department of Textile Engineering, Konkuk University, Mojin-dong 93-1, Kwangjin-gu, Seoul, 143-701, Korea