Kumiko Tanaka-Ishii's Home Page

Professor

Waseda University

About my Research

I am interested in applying complex systems theory to natural language in order to understand its fractal and chaotic properties. My approach integrates large language models and a range of machine learning techniques, along with analytical methods drawn from statistical mechanics.

I apply these insights to the engineering and analysis of large-scale social systems, particularly those shaped by language-mediated interaction and collective dynamics. In addition, I continue to publish philosophical reflections on semiotic systems, with the aim of clarifying the conceptual foundations that link language, artificial intelligence, and social organization.

Previously, I published the following two monographs, both in English and Japanese :

Short Bio

• Professor of Waseda University, 2023-.
• Affiliated fellow of CHIA, University of Cambridge, 2023-.
• Visiting fellow of Clare Hall, University of Cambridge, 2022-2023.
• Professor of University Tokyo, 2016-2023.
• Professor of Kyushu University, 2012-2016.
• Associate professor of University of Tokyo, 2002-2012.
• Lecturer of University of Tokyo, 2000-2002.
• Ph.D. in natural language processing, M.E. in functional programming language, and B.E. in applied mathematics, University of Tokyo.
• Invited student researcher at LIMSI-CNRS France 1995-1996.

Very Short List of my Journal Papers

• Xin Du and Kumiko Tanaka-Ishii.Correlation dimension of natural language in a statistical manifold. Physical Review Research, 6(L022028), 2024.
• Kumiko Tanaka-Ishii and Akira Tanaka. Strahler number of natural language sentences in comparison with random trees. Journal of Statistical Mechanics, 2023(1234034), 2023.
• Shuntaro Takahashi and Kumiko Tanaka-Ishii. Evaluating computational language models with scaling properties of natural language. Computational Lingusitics, 45(3):1–33, 2019.
• Kumiko Tanaka-Ishii and Tatsuru Kobayashi.Taylor’s law for linguistic sequences and random walk models. Journal of Physics Communications, 2(11):115024, 2018. 089401.
• Kumiko Tanaka-Ishii. Void of sign. In Semiotica, number 218, pages 119–135. Mouton de Gruyter, August 2017.
• Kumiko Tanaka-Ishii and Shunsuke Aihara. Computational constancy measures of texts – Yule’s K and R ́enyi’s entropy. Computational Linguistics, 41(3):481–502, 2015.
• Kumiko Tanaka-Ishii and Hiroshi Terada. Word familiarity and frequency. Studia Linguistica, 65(1):96–116, 2010.