Professor, 1996-, Department of Mathematics and Statistics, University of South Florida
Associate Professor, 1992-1996, Department of Mathematics, University of South Florida
Assistant Professor, 1990-1992, Department of Mathematics, University of South Florida
Visiting Assistant Professor, 1989-1990, School of Mathematics, University of Minnesota
Research Assitant Professor, 1988-1999, Department of Mathematics, Purdue University
Ph.D. Graduate Student, 1986-1988, School of Mathematics, University of Minnesota
Lecturer, 1983-1986, Institute of Mathematics, Fudan University