1. Postdoctoral Associate, Electrical and Computer Engineering, Swanson School of Engineering, Univ. of Pittsburgh, Pittsburgh, PA 15261 (corresponding author).
2. Associate Professor, Electrical and Computer Engineering, Swanson School of Engineering, Univ. of Pittsburgh, Pittsburgh, PA 15261.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Rice Univ., Houston, TX 77005.