* Professor,
Department of Electrical Engineering,
Texas A&M University, 1999-2001.
* Visiting Scientist, Texas Instruments, 2001.
* Associate Professor, Texas A&M University, 1992-99.
* Adjunct Associate Professor,
Baylor College of Medicine, 1994-99.
* Visiting Scientist, US Army TACOM Research Lab, Summer 1995.
* Assistant Professor, Texas A&M University, 1986-92.
* Visiting Scientist, AT&T Bell Labs, Summer 1984.
* Research Scientist, Houston Health Science Center, 1983-84.