2019 – present Professor of Mathematics Department, Advisor to Rector, New Uzbekistan University
2019 – 2025 Visiting Professor, College of Business, ADA University, Azerbaijan
1990 – 2019 Professor, Department of Statistics and Actuarial Science, Soongsil University, Korea
- Chair, Statistics Department (1994–1996)
- Dean of Academic Affairs (2005–2007)
- Vice President for Foreign Affairs (2007)
- Dean of Graduate School (2008–2009)
2009 – 2010 Visiting Professor, Towson University, Maryland, USA
2001, 2005 Visiting Scholar, Institute of Statistical Mathematics, Japan
2004 Visiting Scholar, Augsburg University, Germany
1996 – 1997 Visiting Scholar & Research Associate, Rutgers University, USA
1992 – 1993 Visiting Researcher, IBM Watson Research Center, USA
1987 – 1990 Assistant Professor, Department of Business Information Systems & Quantitative Analysis, Mississippi State University, USA
1986 – 1987 Visiting Assistant Professor, Department of Information Systems & Operations Management, University of Toledo, USA
1982 – 1986 Research Associate, Tantalus Inc., Cleveland, Ohio, USA
- Developed a management information system for libraries
1978 – 1981 Full-time Instructor, Department of Mathematics, Korea Military Academy, Seoul
1976 – 1978 Computer Programmer, Seoul National University Computer Center, Korea
- Developed a statistical package