He received his Ph.D. in Information Science and Technology from the University of Tokyo, Japan in 2005. He has published more than 80 papers in international conferences and journals on the text and data mining including ones at WWW, WSDM, ACL, KDD, TKDE, Ubicomp and CIKM. He has served as a PC co-chair of JCDL2017, ICADL2014, SocInfo2013, and tutorial co-chair at SIGIR2017, as well as he was a PC member of over 100 conferences or workshops including also SIGIR, WSDM, WWW, CIKM, AAAI, IJCAI. He has co-organized 10 international workshops on topics of text mining and information search.