1. Intellectual Textile System Research Center (ITRC) and School of Materials Science and Engineering, College of Engineering, Seoul National University, Shillim9dong 56-1, Kwanakgu, Seoul, Korea 151-744, Department of Polymer Science and Technology, Inha University, Yonghyun4dong, Namku, Inchon, Korea, 402-751, and Department of Polymer Science and Technology, Dankook University, Hannamro 147, Yongsanku, Seoul, Korea, 140-714