1. Department of Computer Science, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332 e-mail:
2. Department of Electrical and Computer Engineering, University of Houston, Engineering Bldg 1, 4726 Calhou Road, Houston, TX 77204 e-mail:
3. Department of Mechanical Engineering, University of Houston, Engineering Bldg 1, 4726 Calhoun Road, Houston, TX 77204 e-mail:
4. Department of Mechanical Engineering, University of Houston, Engineering Building 2, 4726 Calhoun Road, Houston, TX 77204 e-mail:
5. Department of Engineering, Texas Southern University, Houston, Leonard H. O. Spearman Technology Building, 3100 Cleburne Avenue, Houston, TX 77004