1. M.C. Gill Composites Center,Viterbi School of Engineering,University of Southern California,3651 Watt Way, VHE-708,Los Angeles, CA 90089e-mail: wtedward@usc.edu
2. HRL Laboratories,3011 Malibu Canyon Road,Malibu, CA 90265e-mail: gchang@hrl.com
3. HRL Laboratories,3011 Malibu Canyon Road,Malibu, CA 90265e-mail: GPMcKnight@hrl.com
4. M.C. Gill Composites Center,Viterbi School of Engineering,University of Southern California,3651 Watt Way, VHE-406,Los Angeles, CA 90089e-mail: nutt@usc.edu