He received the B.S. degree in mathematics from Kyoto University in 1996 and the M.E. and D.E. degrees in information systems from Nara Institute of Science and Technology in 1998 and 2001, respectively. From 2000 to 2003, he was an awarded researcher with Japan Science and Technology Corporation (JST). From 2003 to 2006, he was an assistant professor with Research Division of Digital Library, NAIST. From 2005 to 2006, he was also an assistant professor with Graduate School of Information Science, NAIST.