


We explore the universal properties underlying largescale social systems through mathematical models derived by computing with big data obtained from largescale resources. Using these models, we explore new ways of engineering to aid human social activities.

Month: April 2018
seisanken – omi
Profile
Associate Professor
Institute of Industrial Science, The University of Tokyo
Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo
Aihara lab., Institute of Industrial Science, The University of Tokyo, 461 Komaba, Meguroku, Tokyo 1538505, Japan.
Tel: +81354526697 (Ext. 56697)
Fax:
Email：omi@sat.t.utokyo.ac.jp
Curriculum Vitae
March 2007  Bachelor of Science from Faculty of Science, Kyoto University 

March 2009  Master of Science from Department of Physics, Graduate School of Science, Kyoto University 
March 2012  Ph.D. in Science from Department of Physics, Graduate School of Science, Kyoto University 
April 2012  Researcher, Japan Science and Technology 
April 2013  Japan Society for the Promotion of Science Fellowship for Young Scientists 
April 2016  Project Research Associate, Institute of Industrial Science, The University of Tokyo 
April 2018  Project Associate Professor, Institute of Industrial Science, The University of Tokyo 
Research Themes
Our main topics is timeseries analysis. We especially focus on the statistical analysis of point process data, which describe events that occur irregularly in time. Our research includes
(1) the development of estimation and forecast method based on Bayesian statistics and
(2) its application to earthquake, economic, and social data.
Selected Publications
 T. Omi, Y. Hirata, and K. Aihara,
“Hawkes process model with a timedependent background rate and its application to highfrequency financial data”,
Physical Review E 96, 012303 (2017).  T. Omi, Y. Ogata, Y. Hirata, and K. Aihara,
“Forecasting large aftershocks within one day after the main shock”,
Scientific Reports 3, 2218 (2013).  T. Omi and S. Shinomoto,
“Optimizing time histograms for nonPoissonian spike trains”,
Neural Computation 23, 3125 (2011).
Lab. 1: Nuida
Personal Information
Department of Mathematical Informatics,
Graduate School of Information Science and Technology
Professor
Room 354,Engineering Building 6, 731 Hongo, Bunkyoku, Tokyo, 1138656
Tel: 0358416959 (ext. 26959)
Fax:
Email：nuida@mist.i.utokyo.ac.jp
Biography
March 2001  Bachelor (Science) Department of Mathematics, Faculty of Science, The University of Tokyo, Japan 

March 2003  M.S. (Mathematical Sciences) Graduate School of Mathematical Sciences, The University of Tokyo, Japan 
March 2006  Ph.D. (Mathematical Sciences) Graduate School of Mathematical Sciences, The University of Tokyo, Japan 
April 2006  National Institute of Advanced Industrial Science and Technology, postdoc researcher, Japan 
April 2007  National Institute of Advanced Industrial Science and Technology, researcher 
March 2013  National Institute of Advanced Industrial Science and Technology, senior researcher, Japan 
October 2014  Japan Science and Technology Agency, PRESTO (additional; until March 2018) 
April 2018  Associate Professor, Graduate School of Information Science and Technology, The University of Tokyo, Japan 
Research Themes
The main subjects of my research are cryptography and information security technologies that are bases of security for various information technologies. Examples are as follows:
● Theory of cryptography
Designs and security analyses for cryptographic schemes, particularly aiming at realizing longterm security against future adversaries with highly advanced computational powers.
● Privacypreserving data mining
Secure computation schemes that enable to utilize data while preserving the security/privacy, in various application areas.
● Fundamental mathematics
Mathematical theory including group theory and discrete mathematics, and their application to cryptography.
Main paper and books
 Koji Nuida, Goichiro Hanaoka, “On the security of pseudorandomized informationtheoretically secure schemes”, IEEE Transactions on Information Theory, vol.59, no.1, pp.635652, 2013.
 Koji Nuida, Kaoru Kurosawa, “(Batch) Fully Homomorphic Encryption over Integers for NonBinary Message Spaces”, in: EUROCRYPT 2015 (Part I), LNCS vol.9056, pp.537555, 2015.
 Kana Shimizu, Koji Nuida, Gunnar Ratsch, “Efficient PrivacyPreserving String Search and an Application in Genomics”, Bioinformatics, vol.32, no.11, pp.16521661, 2016.
 Robert B. Howlett, Bernhard Muhlherr, Koji Nuida, “Intrinsic Reflections and Strongly Rigid Coxeter Groups”, Proceedings of the London Mathematical Society, vol.116, no.3, pp.534574, 2018.