· Professor Emeritus, University of Maryland Institute for Advanced Computer Studies2024–
· Professor (Emeritus), University of Maryland Institute for Advanced Computer Studies (UMIACS)2024–
· Interim Chair, Department of Electrical and Computer Engineering, University of Maryland2018–
· Director of Cyberinfrastructure, SESYNC2011–2015
· Interim VP and CIO, University of Maryland2010–
· Director, University of Maryland Institute for Advanced Computer Studies (UMIACS)1994–
· Professor, University of Maryland1987–
· Faculty member (prior to 1983), Penn State University1983–
· Professor, University of Maryland, Department of Electrical and Computer Engineering1983–2024