Koji Imamura

Kumamoto University, Institute of Semiconductor and Digital Research and Education

Koji Imamura

Matroid Theory / Coding Theory / Combinatorics

I work at the intersection of matroid theory and algebraic coding theory, with a focus on both structural theory and applications.

My current work is organised around the following themes.

  • matroid representations over finite rings
  • combinatorial structures of q-polymatroids from rank-metric codes
  • finite-geometry-based constructions of optimal codes

I am also interested in analysis via weight/Tutte polynomials and applications to communication and network coding.My Erdős number is 4(opens in a new tab).

Profile picture of Koji Imamura

I welcome collaboration inquiries, talk invitations, and questions about my research. Please see thecontact sectionandresearch pagefor details.

View Publications

External profiles

Affiliation

Kumamoto University, Institute of Semiconductor and Digital Research and Education

2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan

reisi.kumamoto-u.ac.jp

Contact

For collaboration inquiries, talk invitations, and questions about my research, please contact me using one of the addresses below.

University email

k-imamura[at]kumamoto-u[dot]ac[dot]jp

General (Gmail)

k[dot]imamura[dot]contact[at]gmail[dot]com

For anti-spam reasons, please replace [at] with @ and [dot] with . before sending your email.

Collaboration & Talks

For collaboration or invited talks, please review the research overview and contact details shown above.

Collaboration & Talks

I welcome collaboration and invited talk inquiries related to matroid theory, coding theory, and finite geometry.

View Research Overview

Research Areas

Main research themes

Matroid Theoryマトロイド理論
A matroid is a combinatorial structure that abstracts the notion of linear independence from linear algebra, and matroid theory provides a unified framework for properties shared by codes, graphs, finite geometry, and related objects introduced below.
matroid representationcritical problemcritical exponent
Coding Theory符号理論
Coding theory studies the design of error-correcting codes and their algebraic/combinatorial properties.
linear codesweight enumeratorcodes over rings
Finite Geometry: Projective Geometry有限幾何：射影幾何
Finite geometry studies incidence structures on finite sets. Besides projective and affine geometries over finite fields, it also includes ring-based settings such as projective Hjelmslev geometry, chain geometry, and Laguerre geometry.
finite geometryprojective geometryincidence structure

Selected Works

Selected publications

  • Periodicity of weight enumerators for codes generated by an integral matrix

    Koji Imamura, Norihiro Nakashima, Takuya Saito — arXiv preprint arXiv:2601.21121, 2026

    Preprint analysing periodic behaviour of weight enumerators for sequences of codes generated by an integral matrix.

    arXiv(opens in a new tab)

  • Critical problem for a q-analogue of polymatroids

    Koji Imamura, Keisuke Shiromoto — Discrete Math., 347(5), Paper No. 113924, 13, 2024

    Journal paper formulating the critical problem for a q-analogue of polymatroids, and providing q-analogues of minimal blocks together with concrete examples.

    DOI(opens in a new tab)MathSciNet(opens in a new tab)

  • Critical Problem for codes over finite chain rings

    Koji Imamura, Keisuke Shiromoto — Finite Fields Appl., 76, Paper No. 101900, 14, 2021

    Journal paper on the critical problem for codes over finite chain rings, including upper-bound results.

    DOI(opens in a new tab)MathSciNet(opens in a new tab)
View all publications

News

  • Presented “局所環上のモジュラ独立性を用いたマトロイドの表現問題について” at IMI暗号学セミナー.

  • Released preprint: “Periodicity of weight enumerators for codes generated by an integral matrix”.

    arXiv (arxiv.org)(opens in a new tab)

  • Presented “モジュラ独立性によるマトロイドの表現について” at デザインと符号および関連する組合せ構造2025.

  • Presented “On the independence systems based on modular independence” at 47th Australasian Combinatorics Conference (47ACC).

  • Presented “有限環上の符号に対する臨界問題とその周辺” at 数理・情報系研究集会 @ 熊本.