1. Associate Professor, Sungkyunkwan Univ., Dept. of Architectural Engineering, Suwon, 440-746, Korea. E-mail: schin@skku.edu
2. Research Assistant, Sungkyunkwan Univ., Dept. of Civil, Architectural and Environmental System Engineering, Suwon, 440-746, Korea. E-mail: yoonsuwon@skku.edu
3. CEO, Doalltech, #1403 Aju Building 679-5, Yeoksam-Dong, Gangnam, Seoul, 135-978, Korea. E-mail: choi@doalltech.com
4. Manager, Samsung Corp., Seocho-Dong, Gangnam, Seoul, 1321-15, Korea. E-mail: chocy@samsung.com