Kenji Kajiwara

Kenji Kajiwara

J-GLOBAL         Last updated: Jan 6, 2020 at 16:56
Kenji Kajiwara
Kyushu University
Institute of Mathematics for Industry
Job title
Ph.D (Engineering)
Research funding number


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

Research Grants & Projects

Project Year: Oct 2019 - Mar 2025    Investigator(s): Kenji Kajiwara
We originate a novel geometry of discrete surfaces having the surfaces with good properties, such as developable surfaces, as the shape elements, incorporate the theory of aesthetic shapes and construct the technique of structural analysis/optimiz...
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

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

Nalini Joshi, Kenji Kajiwara, Tetsu Masuda and Nobutaka Nakazono
arXiv:1908.10060      Aug 2019
We derive the cross-ratio equations and similarity constraint that lead to discrete power functions and associated circle patterns on a hexagonal lattice from two starting points: the ABS equations and the Garnier systems. This provides a differen...
Shizuo Kaji, Kenji Kajiwara, Hyeongki Park
Nonlinear Systems and Their Remarkable Mathematical Structures: Volume 2(CRC Press,2019)   356-381   Dec 2019   [Refereed]
A linkage mechanism consists of rigid bodies assembled by joints which can be used to translate and transfer motion from one form in one place to another. In this paper, we are particularly interested in a family of spacial linkage mechanisms whic...
Sebastián Elías Graiff Zurita and Kenji Kajiwara
JSIAM Letters   11 73-76   Dec 2019   [Refereed]
After characterizing the integrable discrete analogue of the Euler's elastica, we focus our attention on the problem of approximating a given discrete planar curve by an appropriate discrete Euler's elastica. We have decided to do the fairing pro...
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
Int. J. Geom. Methods Mod. Phys.   16(7) 1950100   Jul 2019   [Refereed]
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
Journal of Integrable Systems   4(1) xyz003   Jul 2019   [Refereed]
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]


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
   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