1. Postdoctorate Researcher, Dept. of Civil and Environmental Engineering, Stanford Univ., Stanford, CA 94305.
2. PhD Candidate, Dept. of Electrical Engineering, Stanford Univ., Stanford, CA 94305.
3. Professor, Dept. of Civil and Environmental Engineering, Stanford Univ., Stanford, CA 94305.
4. Professor, Dept. of Mechanical Engineering, Stanford Univ., Stanford, CA 94305.