Program Chair
- Technical program co-chair, with Christopher Jermaine and Xiaofang Zhou, Twentyninth IEEE International Conference on Data Engineering, Brisbane, QLD, Australia, April 15–20, 2013.
- Program committee co-chair, with Eyal Ofek and Egemen Tanen, Nineteenth ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems, Chicago, IL, USA, November 1-4, 2011.
- Program committee co-chair, with Ki-Joune Li, Second International Workshop on Indoor Spatial Awareness, San Jose, CA, USA, November 2, 2010.
- Program committee co-chair, with Yanlei Diao, Fifth International Workshop on Data Management for Sensor Networks, Auckland, New Zealand, August 25, 2008.
- Program committee co-chair, with Stéphane Demri, Fifteenth International Symposium on Temporal Representation and Reasoning, Montreal, Canada, June 11–13, 2008.
- Program committee vice chair, Twentyfourth IEEE International Conference on Data Engineering, Cancun, Mexico April 7–12, 2008.
- Program committee co-chair, with Christian Becker and Jianwen Su, Eighth International Conference on Mobile Data Management, Mannheim, Germany, May 7–11, 2007.
- Program committee co-chair, with Panos K. Chrysanthis, Fifth International ACM Workshop on Data Engineering for Wireless and Mobile Access, Chicago, IL, USA, June 25, 2006. (Recipient of an ACM Recognition of Service Award for this service.)
- Technical program chair, Thirtyfirst International Conference on Very Large Databases, Trondheim, Norway, August 30–September 2, 2005.
- Program committee chair, Eighth International Conference on Extending Database Technology, Prague, Czech Republic, March 25–27, 2002.
- Program committee co-chair, with Bernhard Seeger, Seventh International Symposium on Spatial and Temporal Databases, Redondo Beach, CA, USA, July 12–15, 2001.
- Program co-chair, Workshop on Wireless Information Management, Vilnius, Trakai, June 10–13, 2001.
- Program committee co-chair, with Michel Scholl, Workshop on Spatio-Temporal Database Management, Edinburgh, Scotland, September 10–11, 1999 (a VLDB'99 co-located event).
- Program committee vice chair, Fourteenth IEEE International Conference on Data Engineering, Orlando, FL, April 1998 (program co-chairs: Elisa Bertino and Susan Urban).