1. Visiting Scholar, Dept. of Civil and Environment Engineering, The Univ. of Tennessee, Knoxville, TN 37996.
2. Assistant Professor, Dept. of Civil Engineering, Konyang Univ., Nonsan-Si, Chungnam-Do, Korea.
3. Associate Professor, Dept. of Civil and Environment Engineering, The Univ. of Tennessee, Knoxville, TN 37996 (corresponding author).