1. Department of Mechanical Engineering and the Texas Materials Institute, The University of Texas at Austin, 1 University Station C2200, Austin, Texas 78712-0292, United States
2. Department of Electrical Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
3. IBM T. J. Watson Research Center, Yorktown Heights, New York 10598, United States
4. Texas Instruments, 13121 TI Boulevard, Dallas, Texas 75243, United States