Sumio Watanabe

Timeline

1. 1982–1993

   Physics, mathematics and Ricoh

   Born in Nakano, Nagano, in 1959, he earns a B.S. in physics at the University of Tokyo in 1982 and an M.S. in mathematical science at Kyoto University in 1984. He joins Ricoh in 1987 as a researcher at its Research Center of Information and Communication, and completes a doctorate in engineering at Tokyo Institute of Technology in 1993.

2. 1995–2001

   Professor at Tokyo Institute of Technology

   In 1995, he becomes an associate professor in the Department of Mechanical Engineering at Gifu University. He moves to Tokyo Institute of Technology in 1997 as an associate professor at the Precision and Intelligence Laboratory, and becomes a professor there in December 2001.

3. 2006

   The Ichimura Prize for Science

   While a professor at the Precision and Intelligence Laboratory of Tokyo Institute of Technology, he receives the Ichimura Prize for Science in 2006.

4. 2009

   Algebraic geometry and learning theory

   Cambridge University Press publishes his book Algebraic Geometry and Statistical Learning Theory in 2009. The book builds on his discovery of algebro-geometric structures in statistical learning theory and proposes a generalization of Fisher's regular statistical theory to singular statistical models, a class that includes mixture models, neural networks, HMMs and Bayesian networks.

5. 2010–2013

   WAIC and WBIC in JMLR

   In 2010, he publishes a JMLR paper proving that Bayes cross-validation loss and the widely applicable information criterion (WAIC) are asymptotically equivalent in singular learning theory. In 2013, JMLR publishes his paper defining the widely applicable Bayesian information criterion (WBIC), a version of BIC for singular models such as neural networks.

6. 2012–2013

   Department head and IEICE Fellow

   He is head of the Department of Computational Intelligence and Systems Science at Tokyo Institute of Technology from April 2012 to March 2013. In June 2013, he is named an IEICE Fellow.

7. 2017–2018

   ICANN award and CRC Press book

   In 2017, he and Masahiro Kohjima win a Best Paper Award at the 26th International Conference on Artificial Neural Networks in Alghero, Italy, for Phase Transition Structure of Variational Bayesian Nonnegative Matrix Factorization. CRC Press publishes his book Mathematical Theory of Bayesian Statistics in 2018; it introduces the mathematical foundation of Bayesian inference and studies cross validation and information criteria.

8. Since April 2024

   Emeritus professor and RIKEN AIP

   He becomes professor emeritus of Tokyo Institute of Technology in April 2024, and the university becomes Institute of Science Tokyo in October 2024. In May 2024, he joins the RIKEN Center for Advanced Intelligence Project as a visiting senior scientist, and in June 2025 he publishes an invited review in Reviews in Mathematical Physics on algebraic research linking statistical mechanics and machine learning theory.