- 2024.9.14-2024.10.13, Shenzhen Institute of Computing Sciences, China, Visiting Scholar
- 2021.4.14-2021.5.13, Peking University, China, Visiting Scholar
- 2018.6-2018.8, Potsdam University, Germany, Visiting Scholar
- 2016.5-2016.8, Texas Tech University, USA, Visiting Scholar
- 2014.6-2014.8, Griffith University, AU, Visiting Scholar
- 2012.12-2013.5, Griffith University, AU, Visiting Scholar
- 2011.6-2011.11, Western Sydney University, AU, Visiting Scholar
- 2009.5-2010.4, Alberta University of Canada, CA, PostDoc
- 2007.10-2008.10,Hong Kong University of Science and Technolody, HK, PostDoc
- 2005.3-2005.6, Hong Kong University of Science and Technolody, HK, Visiting Scholar
- 2002.9-2002.12, Leicester University, UK, Visiting Scholar
Compute minimal beta-witness for answer sets of logic programs
Compute minimal models based on python-sat (By Zhongtao Xie)
Computation propositional logical difference
Learning disjunctive logic programs from state transitions
Learning Horn programs from input and output (by Xu Wang)
Answer set programs with function