Life distribution, Reliability theory and applications for hardware system evaluation and maintenance policy, Software reliability growth model

1982~1983 Assistant Professor, Temple University, USA
1983~1993 Assistant and Associate Professor (with tenure), Univerisity of Nebraska, USA
1992~1993 Director, Division of Statistics, University of Nebraska
1990~1991 Visiting Professor, POSTECH
1993~ Professor, Hallym University, Chuncheon
1995~1997 Dean of Library, Hallym University
1999~2004 Founder and President (1st, 2nd), The Korean Reliability Society (KORAS)
2001~2002 Dean, College of Natural Sciences, Hallym University
2004~ Honorary President, KORAS
2005~2009 Member, Reliability Advisory Committee
2007~ Adjunct Professor, University of North Texas, USA
2007~2009 Director of Graduate School, Hallym University
2007~ Chairman, University Advisory Council, Hallym University

2004 Materials and Components Technology Award (Prime Minister)
2004 Outstanding Contribution Award, The Korean Reliability Society
2008 Excellent Research Award, The Korean Reliability Society
2009 Jinbo Medal (President of Korea)