7/12-present: Chancellor’s Professor, Computer Science and Engineering, University of California, Merced, CA 95343.
9/01-6/12: Full Professor and Gartner Group Endowed Chair in Network Engineering, Dept. of Computer Science, The University of Kentucky, Lexington, KY 40506.
2/86-9/01: Assistant, Associate, and Full Professor, Dept. of Computer Science and Engineering, The Ohio State University, Columbus, OH 43210.
9/98-8/01: Program Director, “Operating Systems and Compilers” Program, The Directorate of Computer and Information Science and Engineering, National Science Foundation. (On leave from Ohio State University under the Intergovernmental Personnel Act).
1/81-1/86: Teaching Assistant/ Research Assistant/ Faculty Research Associate, Dept. of Computer Science, University of Maryland, College Park, MD 20742.