1. Research Associate, Dept. of Civil and Environmental Engineering, Duke Univ., 118a Hudson Hall, Durham, NC 27708.
2. Research Associate, School of Mechanical Engineering, Tel-Aviv Univ., Tel-Aviv 69978, Israel.
3. Associate Professor, Dept. of Civil, Construction, and Environmental Engineering, North Carolina State Univ., 319c Mann Hall, Raleigh, NC 27695.
4. Associate Professor, Dept. of Civil and Environmental Engineering, Duke Univ., 118a Hudson Hall, Durham, NC 27708 (corresponding author).