2012-09 to 2023-05 , Professor (Language Technologies Institute), Carnegie Mellon University

Research Professor (Jul 2015--) at the Language Technologies Institute of Carnegie Mellon University, Pittsburgh, PA

Associate Research Professor (Sep 2012 -- Jun 2015) at the Language Technologies Institute of Carnegie Mellon University, Pittsburgh, PA

Research Area Co-Lead (2017--), Center for Criminal Investigation and Network Analysis (CINA)

Co-Director for Research (May 2009 -- Jun 2016) of the Command, Control, and Interoperability Center for Advanced Data Analysis (CCICADA)

Research Associate Professor (Nov 1999 --) Department of Computer Science, University of Southern California, Los Angeles, CA

Research Assistant Professor (Dec 1989 -- Oct 1999), Department of Computer Science, University of Southern California, Los Angeles, CA

Advisory Professor (Oct 2005 -- Aug 2015), Beijing University of Posts and Telecommunications, Beijing, China

Adjunct Professor (Feb 1997 -- Jan 2003), School of Computer Science, University of Waterloo, Waterloo, Canada

Adjunct Professor (May 2010 -- Apr 2015), School of Computer Science, University of Waterloo, Waterloo, Canada

Information Sciences Institute of the University of Southern California, Los Angeles, CA, Division Director (2011 -- 2012)

Information Sciences Institute of the University of Southern California, Los Angeles, CA, ISI Fellow (Aug 2000 -- 2012)

Information Sciences Institute of the University of Southern California, Los Angeles, CA, Deputy Division Director (Oct 2002 -- 2011)

Information Sciences Institute of the University of Southern California, Los Angeles, CA, Senior Project Leader (May 1997 -- 2002)

Information Sciences Institute of the University of Southern California, Los Angeles, CA, Project Leader (Jul 1989 -- Apr 1997)

Information Sciences Institute of the University of Southern California, Los Angeles, CA, Computer Scientist (Mar 1987 -- Jun 1989)

Adjunct Professor (Sep 2005 -- Aug 2012), Department of Computer Science, KAIST, Daejeon, Korea

Concurrent Professor (Oct 2008 -- Sep 2011), Department of Computer Science, Northeastern University, Shenyang, China

Director of Research (2000 -- 2008) of the Digital Government Research Center DGRC at the Information Sciences Institute of the University of Southern California, Los Angeles, CA

Co-Director (May 1999 -- Jun 2005), Master's Degree Program in Computational Linguistics, University of Southern California, Los Angeles, CA