2000 - 2006 Chair Professor, Department of Computing, The Hong Kong Polytechnic University 1996 - 1999 Chair Professor and Head, Department of Computing, The Hong Kong Polytechnic University 1992 - 1995 Professor and Head, Department of Computing, The Hong Kong Polytechnic University 1991 - 1992 Head, Management Information Unit, Hong Kong Polytechnic 1988 - 1990 Associate Head/Principal Lecturer, Department of Computer Science, City Polytechnic of Hong Kong 1979 - 1980 Tenured Assistant Professor, School of Computer Science and Technology, Rochester Institute of Technology, Rochester, New York, USA 1974 - 1979 Assistant Professor, Department of Mathematics, Rochester Institute of Technology, Rochester, New York, USA