1. Professor, Dept. of Mechanical and Aerospace Engineering, Rutgers Univ., Piscataway, NJ 08854 (corresponding author).
2. Professor, Dept. of Civil Engineering, North Carolina State Univ., Raleigh, NC 27695.
3. Professor, Dept. of Civil Engineering, Univ. of New Mexico, Albuquerque, NM 87131.