1. Associate Professor, Dept. of Civil and Environmental Engineering, Hanyang Univ., Ansan, Kyonggi-Do 425-791, Korea.
2. Postdoctoral Research Fellow, Dept. of Civil and Environmental Engineering, Hanyang Univ., Ansan, Kyonggi-Do 425-791, Korea (corresponding author).
3. Doctoral Student, Dept. of Communication, Michigan State Univ., East Lansing, MI 48824.
4. Assistant Professor, Dept. of Communication, Michigan State Univ., East Lansing, MI 48824.