User:渡部大志/Ichiro Tsuda

Ichiro Tsuda (June 4, 1953-) is a Japanese mathematical scientist, applied mathematician, physicist, and writer. He is one of the pioneers in the field of chaos studies [1], and one of the leading researchers in complex systems science in Japan[2]. He was among the first to investigate brain dynamics, introducing chaotic brain theory and cerebral hermeneutics [3]. He is also known as the first person to demonstrate the existence of chaos in the Belousov-Zhabotinsky chemical reaction systems by combining an empirical Lorenz plot and a one-dimensional discrete-time dynamical system model[4][5] when he was a graduate student.

Biography
Born in Okayama Prefecture. Doctor of Science in Physics from Kyoto University in 1982 for the research on "Chaos and Bifurcation Structures in Nonlinear and Nonequilibrium Systems". He became a professor at the Department of Mathematics, Hokkaido University in October 1993, a professor at the Research Institute of Electronic Science, Hokkaido University in October 2005, a director of the Center for Collaborative Research in Mathematics, Hokkaido University from 2008 to 2015, a deputy director of the Research Institute of Electronic Science, Hokkaido University from 2012 to 2013, a professor at the Department of Mathematics, Hokkaido University in October 2015, and a professor at the Chubu University Academy of Emerging Sciences, Chubu University since 2017 after retiring Hokkaido University. He was awarded Professor Emeritus from Hokkaido University. Currently, he holds the position of Director and Professor at the Chubu University Academy of Emerging Sciences. He is was a member of the 23rd and 24th Science Council of Japan, and currently a member of the Mathematical Society of Japan, the Physical Society of Japan, the Japan Neuroscience Society, Japanese Neural Network Society, the Biophysical Society of Japan, the Japan Society for Industrial and Applied Mathematics, the Japan Writers’ Association, American Association for the Advancement of Science (AAAS), and Society for Industrial and Applied Mathematics (SIAM). He Additionally, he is a certified cross-country ski instructor and examiner of Ski Association of Japan[7].

Research History
He is known for jointly proposing the concept of chaotic itinerancy with Kensuke Ikeda and Kunihiko Kaneko[8][9] (1987-1991), and devising many mathematical models for the generation mechanism of chaotic itinerancy[10][11]. Together with Kenji Matsumoto, he discovered noise-induced order (1983), in which an ordered state emerges by adding noise to chaos[12][13]. Chaotic itinerancy and noise-induced order are the pioneering theoretical constructs of high-dimensional nonhyperbolic dynamical systems and random dynamical systems, respectively in mathematics. With the help of computer-aided proof, these two concepts were rigorously proved to exist by Italian and Brazilian mathematicians, almost 30 years after their publication [14],[15]

He also contributed to the development of computational neuroscience by paving the way for the introduction of nonlinear mathematical methods in neuroscience. Particularly, he first published a paper on cerebral hermeneutics in 1984, where he claims the significance of chaos in the neural mechanism of the interpretation process of the brain[3]. Since then, he has published many research results elucidating the dynamic activity and information structure of the brain using chaotic dynamical systems, and has received high acclaim the academic societies[16][17]. His representative achievements on the brain include the realization of chaotic associative memory using a nonequilibrium neural network model[18][19], the Cantor coding hypothesis of episodic memory in the hippocampus[20][21] and its demonstration using hippocampal slices[22], research on thinking and reasoning mechanisms in humans and animals[23][24], and functional differentiation of the brain [25], [28] [*][**],and visual hallucinations[26],[27],[29], and mathematical analysis of epileptic seizures [\][\\]. In recent years, he has attracted attention by proposing the theory of constrained conditional self-organization, extending the conventional self-organization theory in the development of mathematical methods to elucidate functional differentiation of the brain[28][***] and its application with reservoir computers to rapid adaptation of robots[+].

He also proposed a new scientific methodology based on the quartet of experiment, theory, interpretation, and composition for complex systems that are difficult to elucidate using conventional reductionist methods [3][16][17]. Based on the method of extracting mathematical structures of a family of chaotic dynamical systems from the neural dynamics[#], he pioneered the study of complex systems science by initiating the constructivist methodology of "interpretation and understanding by making," and has made significant contributions to the development of complex and interdisciplinary scientific fields.

Awards
Japanese Neural Network Society Academic Award 2020 “for longstanding contributions to the development of the field of neural networks, especially through the publication of excellent research papers”. - Plenary Lecture at 2019 IJCNN - Merit Award at 2013 ICCN “for pioneering work in the establishment and development of the field of cognitive neurodynamics, editing its journals, and organizing and managing its international conferences (ICCN)”  -2010 HFSP Program Award “for international collaborative research on the neural mechanisms of  deliberative decision making in rats. (Jointly awarded with David Redish, Jan Lauwereyns, Emma Wood, and Paul Dudchenko) - Plenary Lecture at the 6th ICIAM 2007. - Plenary Lecture at the 1st SIAM Pacific Rim Conference on Dynamical Systems in 2000.
 * The 11th Hiroshi Fujiwara Mathematical Science s Award Grand Prize 2022 "for pioneering contributions to complex brain science based on chaotic dynamics”.

Book
K. Kaneko and I. Tsuda, Complex Systems: Chaos and Beyond — A Constructive Approach with Applications in Life Sciences. Springer-Verlag Berlin, Heidelberg, New York, 2001. Additionally, he has published esteemed books written in Japanese.

Japanese Translation
Kathleen.T. Alligood, Tim D. Sauer, and James A. Yorke, Chaos. An Introduction to Dynamical Systems (Springer-Verlag, New York, 1997): The Japanese edition was published by Springer Japan in 2006 and 2007, and by Maruzen Publishing Co., Ltd., in 2012.

Robert Shaw, The Dripping Faucet as a Model Chaotic System (Aerial Press, Inc. 1984): The Japanese edition translated with Yuzuru Sato was published by Iwanami Shoten, Publishers, Tokyo in 2006.