1. Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095-153, United States
2. RTI International, Research Triangle Park, North Carolina 27709, United States
3. Department of Energy, National Renewable Energy Lab, Golden, Colorado 80401, United States
4. Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
5. Department of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel