Organization & Chair

	Co-Organizer (together with Shivnath Babu) of 5th International Workshop on Self Managing Database Systems (SMDB'10), Long Beach, CA, March 2010.
	Co-Organizer (together with Goetz Graefe, Arnd-Christian König, Harumi Kuno, Volker Markl) of the Dagstuhl Seminar on Robust Query Processing, October 2010.
	Co-Organizer (together with Karl Aberer, Avigdor Gal, Manfred Hauswirth, Amit Sheth) of the Dagstuhl Seminar on Semantic Challenges in Sensor Networks, 2010.
	PC Co-Chair of 14th Int. Conference on Information Quality (ICIQ), Potsdam, Germany, November 2009.
	Co-Organizer (together with Harald Schöning and Gottfried Vossen) of the BTW-Workshop "Database as a Service", Münster, Germany, March 2009.
	Co-Organizer (together with Stefan Conrad and Cristian Perez de Laborda) of the 11th Int. Workshop on Foundations of Models and Languages for Data and Objects (FMLDO) - Query Languages and Query Processing QLQP-2006, Munich, Germany, March 30-31, 2006.
	Co-Organizer (together with Michael Gertz, Tamer Özsu, and Gunter Saake) of the Dagstuhl-Seminar "Data Quality on the Web", Schloss Dagstuhl, 31.8.-5.9.2003.
	Co-Editor of the German Database Journal "Datenbank-Spektrum".

PC Memberships

	36th International Conference on Very Large Databases (VLDB 2010), Singapore, August 2010.
	26th International Conference on Data Engineering (ICDE 2010), Los Angeles, CA, 2010.
	11th International Conference on Mobile Data Management (MDM 2010), Kansas City, Missouri, USA, May 2010.
	8th International Semantic Web Conference (ISWC 2009), Washington, DC, USA, October 2009.
	7th International Workshop on Quality in Databases (QDB 2009), Lyon, France, August 2009.
	9th International Conference on Peer-to-Peer Computing (P2P2009), Seattle, WA, 2009.
	1st International Workshop on the Semantic Sensor Web (SemSensWeb 2009), Heraklion, Greece, 2009.
	7th International Conference on Cooperative Information Systems (CoopIS 2009), Vilamoura, Portugal, 2009.
	Advanced Knowledge-based Systems - Invited Session of the 13th Int. Conference on Knowledge-based and Intelligent Information & Engineering Systems (KES 2009), September, 2009, Santiago, Chile.
	1st Int. Conference on Advances in P2P Systems (A2P2PS 2009), October, 2009 - Sliema, Malta.
	9th Annual Symposium on Applications & the Internet (SAINT2009), Seattle, 2009.
	2009 IEEE Int. Conf. on Research, Innovation and Vision for the Future on Computing and Communication Technologies (IEEE-RIVF'09)Da Nang University of Technology, Viet Nam, July 2009.
	13th Int. Database Engineering & Applications Symposium (IDEAS) 2009, Cetraro - Calabria - Italy, September 2009.
	6th European Semantic Web Conference (ESWC 2009), Heraklion, Greece, June 2009.
	ACM SIGMOD 2009, Demonstration Track, Providence, Rhode Island, June 2009.
	13. GI-Fachtagung "Datenbanksysteme für Business, Technologie und Web" (BTW 2009), Muenster, Germany, March 2009.
	8th IEEE Conference on Peer-to-Peer Computing (P2P2008), Sep, 2008, Aachen, Germany, 2008.
	16th International Conference on Cooperative Information Systems (CoopIS 2008), Nov 9-14, Monterrey, Mexico, 2008.
	1st Int Workshop on Computational P2P Networks: Theory & Practice (ComP2P 2008), Athens, Greece, 2008.
	12th Int. Database Engineering & Applications Symposium (IDEAS) 2008, Muenster, Germany, September 2008.
	Invited Session "Advanced Knowledge-based Systems" of the LNCS/LNAI 12nd International Conference on Knowledge-based and Intelligent Information & Engineering Systems (KES 2008), September 3-5, 2008, Zagreb, Croatia.
	Intl Workshop on the Role of Services, Ontologies, and Context in Mobile Environments (RoSOC-M)held as part of the IEEE Mobile Data Management Conference MDM 2008, Bejing, China, April 2008.
	SAINT 2008 - The 2008 Symposium on Applications & the Internet, Turku, Finland, August 2008.
	19th Int. Conference on Database and Expert Systems Applications (DEXA 2008), Turin, Italy, 2008.
	5th European Semantic Web Conference (ESWC 2008), Tenerife, Spain, June 2008.
	3rd Int. Workshop on Self-Managing Database Systems (SMDB 2008) In conjunction with the 24th Int. Conference on Data Engineering (ICDE 2008), Cancun, Mexico, April 2008.
	Int. Workshop on Peer-to-Peer Networked Virtual Environments 2007 (P2P-NVE 2007) in conjunction with The 13th International Conference on Parallel and Distributed Systems (ICPADS 2007), Hsinchu, Taiwan, December 2007.
	Int. VLDB-Workshop on Semantic Data and Service Integration (SDSI 2007), Vienna, Sep 2007.
	11th Int. Database Applications & Engineering Symposium IDEAS 2007, Banff, Canada, Sep 2007.
	the 15th International Conference on Cooperative Information Systems (CoopIS 2007), Oct 28-Nov 2, 2007.
	7th IEEE Conference on Peer-to-Peer Computing (P2P2007), Sep 2-5, 2007, Galway, Ireland.
	Workshop on Data Integration in the Life Sciences 2007 (DILS'07), June 27-29, 2007, Philadelphia, PA.
	2nd Int. Workshop on Managing Context Information and Semantics in Mobile Environments (MCISME'07), to be held in conjunction with MDM 2007 on May 12 in Mannheim, Germany.
	1st International Workshop on Data Intensive Sensor Networks (DISN'07), to be held in conjunction with MDM 2007 on May 12 in Mannheim, Germany.
	4th European Semantic Web Conference, 3-7th, June 2007, Innsbruck, Austria.
	Special Track "Advances in Querying Non-Conventional Data Sources" of the 3rd Int. Advanced Database Conference (IADC 2007), April 4-6, 2007, San Diego, California, USA.
	12. GI-Fachtagung "Datenbanksysteme für Business, Technologie und Web" (BTW 2007), Aachen, Germany, March 2007.
	2. Konferenz Mobilität und Mobile Informationssysteme (MMS 2007), Aachen, Germany, March 2007.
	18 th Int. Conference on Database and Expert Systems Applications (DEXA 2007), Regensburg, Germany, 2007.
	SAINT 2007 - The 2007 Symposium on Applications & the Internet, Hiroshima, Japan, January 2007.
	1st Int. VLDB Workshop on Clean Databases CleanDB 2006, Seoul, Korea, Sep 2006.
	10th Int. Database Applications & Engineering Symposium IDEAS 2006, Delhi, India, Dec 2006.
	11th Int. Conference on Information Quality ICIQ 2006, Boston, MA, Nov, 2006.
	4th Int. Workshop on Distributed and Mobile Collaboration (DMC 2006) University of Manchester, UK, June 26-28, 2006.
	Int. Workshop on "Managing Context Information and Semantics in Mobile Environments (MCISME)", in conjuction with the 7th Int. Conference on Mobile Data Management (MDM'06), May 9-12, 2006, Nara, Japan.
	Int. Workshop on Security and Trust in Decentralized/Distributed Data Structures (STD3S), in conjuction with the 22nd International Conference on Data Engineering (ICDE'06), April 3-7, 2006, Atlanta, GA, USA.
	2nd Int. Workshop on Pervasive Information Management (PIM 2006), Munich, Germany, March 30, 2006.
	10th Int. Conference on Information Quality ICIQ 2005, Boston, MA, 4-6 Nov, 2005.
	13th Int. Conference on Cooperative Information Systems CoopIS 2005, Agia Napa, Cyprus, 31 Oct-4 Nov, 2005.
	1st Workshop on Semantics in Mobile Environments (SME'05) in conjuction with the 6th International Conference on Mobile Data Management (MDM'05), May 9 2005, Agia Napa, Cyprus.
	Workshop on Database Interoperability (InterDB'05) in conjuction with COORDINATION 2005, April 23 2005, Namur, Belgium.
	GI Workshop Mobile Datenbanken: heute, morgen und in 20 Jahren, Karlsruhe, Germany, 28 Feb, 2005.
	9th International Database Engineering and Applications Symposium (IDEAS), Montreal, Canada, July 25-27, 2005.
	12th Int. Conference on Cooperative Information Systems CoopIS 2004, Larnaca, Cyprus, 25-29 Oct, 2004.
	GI Workshop Dynamische Informationsfusion in conjunction with the GI-Jahrestagung Informatik 2004, Ulm, Germany, September 2004.
	Int. Workshop on Information Quality in Information Systems IQIS'04 in conjunction with SIGMOD-PODS 2004, Paris, France, June 12-13, 2004.
	1st Int. Symposium on Applications of Constraint Databases in conjunction with SIGMOD-PODS 2004, Paris, France, June 12-13, 2004.
	Workshop on Pervasive Information Management in conjunction with EDBT 2004, Heraklion, Crete 2004.
	Workshop on Data Integration in the Life Sciences (DILS 2004), Leipzig 2004.
	10. GI-Fachtagung Datenbanksysteme für Business, Technologie und Web (BTW 2003), Leipzig.

Journal Reviews

	ACM Transactions on Database Systems
	VLDB Journal
	Information Systems
	IEEE Transactions on Parallel and Distributed Systems
	Journal of Systems and Software
	Journal for Applied Logic
	Data & Knowledge Engineering
	Informatik - Forschung & Entwicklung