I have served as a member of program committee of:
The 11th Pacific-Asia Conference on Knowledge Discovery and Data Mining (PAKDD 2007, Nanjing, China, 23 - 25 May 2007), The 2006 IEEE International Conference on Data Mining (ICDM'06, Hong Kong, 18 - 22 December 2006, Area-chair), 5th International Workshop on Knowledge Discovery in Inductive Databases (KDID'06, Berlin, 18 September 2006, in conjunction with ECML/PKDD'06), Workshop on Integrating AI and Data Mining (AIDM'06, Tasmania, Australia, 4 - 8 December 2006, in conjunction with the 19th Australian Joint Conf. on Artif. Intell.), 8th International Colloquium on Grammatical Inference (ICGI-2006, Tokyo, Japan, 20 - 22 September 2006), 8th International Colloquium on Grammatical Inference (ICGI-2006, Tokyo, Japan, 20 - 22 September 2006), the 2006 Pacific Rim International Conference on Artificial Intelligence (PRICAI-2006, Guilin, China, 7-11 August 2006), Fourth Workshop on Learning with Logics and Logics for Learning (LLLL2006, Tokyo, Japan, 5 - 6 June 2006), the 10th Pacific-Asia Conference on Knowledge Discovery and Data Mining (PAKDD'06, Singapore, 9-12 April 2006), Workshop on Knowledge Discovery from XML Documents (KDXD 2006 in conjunction with PAKDD'06, Singapore, April 2006), the 2nd Japanese-German Frontiers of Science (2nd JGFoS), Planning Group Member (November 2005, Hayama, Japan, by JSPS and AvH), the Fifth IEEE International Conference on Data Mining (ICDM'05, New Orleans, Louisiana, USA, November 26-30, 2005), The 16th International Conference on Algorithmic Learning Theory (ALT'05, Singapore, October 8 - 11, 2005), the 22nd International Conference on Machine Learning (Bonn, Germany, August 7-11, 2005), the Third International Workshop on Mining Graphs, Trees and Sequences (MGTS 2005, proposal submitted), the 9th Pacific-Asia Conference on Knowledge Discovery and Data Mining (PAKDD'05, Hanoi, Vietnam, 2005), JGFoS (Japanese-German Frontiers of Science, JSPS-AvH) (Jan. 2005, Germany) Planning Group Member, the Second International Workshop on Mining Graphs, Trees and Sequences (MGTS 2004, Sep. 24, 2004, in conjunction with ECML/PKDD'04, Pisa), the Fourth IEEE International Conference on Data Mining (ICDM'04, Brighton, UK, Nov 01-04, 2004), 6th International Conference on Data Warehousing and Knowledge Discovery (DaWaK'04, Zaragoza, Spain, Aug 30-Sep 3, 2004), the 2003 IEEE International Conference on Data Mining (ICDM'03, Melbourne, Florida, 19-21 Nov. 2003), the 14th International Conference on Algorithmic Learning Theory (ALT'03, 17-19 Oct. 2003, Sapporo), the 5th International Conference on Data Warehousing and Knowledge Discovery (DaWaK 2003), First International Workshop on Mining Graphs, Trees and Sequences (MGTS-2003, in conjunction with PKDD-2003, Cavtat-Dubrovnik, Croatia, September 22-23, 2003), the 2002 IEEE International Conference on Data Mining (ICDM'02, Maebashi, 9-12 Dec. 2002), the Nineteenth International Conference on Machine Learning (ICML-2002, 8-12 July 2002, Sydney), the 4th International Conference on Data Warehousing and Knowledge Discovery (DaWaK 2002), the 12th International Conference on Algorithmic Learning Theory (ALT'01, 26-29  Nov. 2001, Washington, DC), the Eighteenth International Conference on Machine Learning (ICML-2001, June 28-July 1, 2001), the 3rd International Conference on Data Warehousing and Knowledge Discovery (DaWaK 2001, 3-7 Sep 2001, Munich), the 3rd International Conference on Discovery Science (DS2000, Tokyo), the 4th Pacific-Asia Conference on Knowledge Discovery and Data Mining (PAKDD2000, Kyoto), the 7th International Workshop on Algorithmic Learning Theory (ALT'96, Sydney).
I have also served as a program co-chair of the 11th International Conference on Algorithmic Learning Theory (ALT'00, Sydney).