Kenji Kajiwara

J-GLOBAL         Last updated: Aug 10, 2018 at 10:53
Kenji Kajiwara
Kyushu University
Institute of Mathematics for Industry
Job title
Ph.D (Engineering)


Born in 1964. I am interested in the discrete differential geometry and the theory of integrable systems.

Academic & Professional Experience

Jul 2018
Adjunct Professor, School of Mathematics and Statistics, La Trobe University
Apr 2011
Professor, Institute of Mathematics for Industry,, Kyushu University
Jan 2009
Mar 2011
Professor, Faculty of Mathematics, Kyushu University
Oct 2001
Jan 2009
Associate Professor, Faculty of Mathematics, Kyushu University
Apr 1997
Sep 2001
Associate Professor, Department of Electrical Engineering, Doshisha University

Committee Memberships

Journal of Integrable Systems  Editorial Board
Pacific Journal of Mathematics for Industry  Editorial Board
Journal of Physics A: Mathematical and Theoretical  Editorial Board
Journal of Nonlinear Mathematical Physics  Editorial Board
May 2012
Apr 2014
Japan Society for Industrial and Applied Mathematics  Board Member

Published Papers

Jun-ichi Inoguchi, Kenji Kajiwara, Kenjiro T. Miura, Hyeongki Park and Wolfgang K. Schief
arXiv:1808.03104      Aug 2018
In this paper, we consider a class of plane curves called log-aesthetic curves and their generalization which is used in CAGD. We consider these curves in the context of similarity geometry and characterize them in terms of a ``stationary'' integr...
Hyeongki Park, Kenji Kajiwara, Takashi Kurose and Nozomu Matsuura
JSIAM Letters   10 25-28   Jul 2018   [Refereed]
We show that plane curves in the centroaffine geometry admit a flow which is described by
the defocusing modified KdV equation. We establish a correspondence between this flow and
the KdV flow in the equicentroaffine geometry. We also present an e...
Hyeongki Park, Jun-ichi Inoguchi, Kenji Kajiwara, Ken-ichi Maruno, Nozomu Matsuura and Yasuhiro Ohta
preprint, arXiv:1807.07736      Jul 2018
We formulate an isoperimetric deformation of curves on the Minkowski plane, which is governed by the defocusing mKdV equation. Two classes of exact solutions to the defocusing mKdV equation are also presented in terms of the τ functions. By using ...
Jun-ichi Inoguchi, Kenji Kajiwara, Kenjiro T. Miura, Masayuki Sato, Wolfgang K. Schief, Yasuhiro Shimizu
Computer Aided Geometric Design   61 1-5   Mar 2018   [Refereed]
In this paper we consider the log-aesthetic curves and their generalization which are used in CAGD. We consider those curves under similarity geometry and characterize them as stationary integrable flow on plane curves which is governed by the Bur...
K.T. Miura, S. Suzuki, R.U. Gobithaasan, S. Usuki, J. Inoguchi, M. Sato, K. Kajiwara, Y. Shimizu
Computer-Aided Design and Applications      Oct 2017   [Refereed]
A curve is considered fair if it consists of continuous and few monotonic curvature segments. Polynomial curves such as Bézier and B-spline curves have complex curvature function, hence the curvature
profile may oscillate easily with a little twea...
Sampei Hirose, Jun-ichi Inoguchi, Kenji Kajiwara, Nozomu Matsuura and Yasuhiro Ohta
preprint, arXiv:1708.01704      Aug 2017
The local induction equation, or the binormal flow on space curves is a well-known model of
deformation of space curves as it describes the dynamics of vortex filaments, and the complex
curvature is governed by the nonlinear Schrödinger equation. ...
Dimetre Triadis, Philip Broadbridge, Kenji Kajiwara and Ken-ichi Maruno
Stud. Appl. Math.      Mar 2018   [Refereed]
Nalini Joshi, Kenji Kajiwara, Tetsu Masuda, Nobutaka Nakazono and Yang Shi
Proc. R. Soc. A 473 20170312      Oct 2017   [Refereed]
Kenji Kajiwara, Masatoshi Noumi and Yasuhiko Yamada
J. Phys. A: Math. Theoret.   50(7) 073001   Jan 2017   [Refereed]
In this paper a comprehensive review is given on the current status of
achievements in the geometric aspects of the Painlevé equations, with a
particular emphasis on the discrete Painlevé equations. The theory is
controlled by the geometry of ...
Kenji Kajiwara, Toshinobu Kuroda and Nozomu Matsuura
Pacific Journal of Mathematics for Industry   8(1) 1-14   Mar 2016   [Refereed]
We study deformations of plane curves in the similarity geometry. It is known that continuous deformations of smooth curves are described by the Burgers hierarchy. In this paper, we formulate the discrete deformation of discrete plane curves descr...


Discrete Model of Isoperimetric Deformations of Planar Discrete Curve and DIscrete Integrabls Systems
Kenji Kajiwara
MI Lecture Note "Mathematical Approaches to Research Topics in Science and Technology-Foundation and Development of Mathematical Modeling"   46 57-62   Mar 2013   [Invited]
Introduction to Integrable Systems
Kenji Kajiwara
MI Lecture Note "Tutorial on Discrete Integrable Systems and Discrete Differential Geometry 2012"   40 1-24   Mar 2012   [Invited]
Daisuke Takahashi,Kenji Kajiwara
   Mar 1999
We consider an integrability test for ultradiscrete equations based on the
singularity confinement analysis for discrete equations. We show how
singularity pattern of the test is transformed into that of ultradiscrete
equation. The ultradiscrete s...
Kenji Kajiwara, Yasuhiro Ohta, Junkichi Satsuma, Basil Grammaticos, Alfred Ramani
Journal of Physics. A. Proceedings of the Physical Society. A. General   27(3) 915-922   Oct 1993
We present a class of solutions to the discrete Painlevé-II equation for
particular values of its parameters. It is shown that these solutions can be
expressed in terms of Casorati determinants whose entries are discrete Airy
functions. The anal...

Books etc

Tutorial on Discrete Integrable Systems and Discrete Differential Geometry 2012
Jun-ichi Inoguchi, Yasuhiro Ohta, Saburo Kakei, Kenji Kajiwara, Nozomu Matsuura (Part:Editor)
Institute of Mathemaics for Industry, Faculty of Mathematics, Kyushu University   Mar 2012   
岩波書店   Mar 2010   ISBN:4000052055
丸善   Mar 2005   ISBN:4621075292
中村 佳正, 渡辺 芳英, 西成 活裕, 松木平 淳太, 永井 敦, 辻本 諭, 佐々 成正, 梶原 健司
裳華房   Jun 2000   ISBN:4785315202

Research Grants & Projects

Development and Extension of Integrable Discrete Differential Geometry
JSPS: KAKENHI (Scientific Research (B))
Project Year: Apr 2016 - Mar 2020    Investigator(s): Kenji Kajiwara
Construction of Discrete-time Geometric Models Based on Discrete Differential Geometry
JSPS: KAKENHI (Challenging Exploratory Research)
Project Year: Apr 2016 - Mar 2018    Investigator(s): Kenji Kajiwara
Modeling for CG based on discrete integrable systems
Kobe Studio Seminar: 
Project Year: Jan 2016       Investigator(s): Kenji Kajiwara
The purpose of this project is to develop modelling technique for computer graphics based on
discrete integrable systems. The theory of discrete integrable systems provides skeletons of
dynamics of geometric objects such as discrete curves and di...