On a property of $2$-dimensional integral Euclidean lattices,
8th Symposium on Algebra and Computation (AC2009),
Tokyo Metropolitan University, December 2, 2009.
On the zeros of polynomials
related to the extremal vertex operator algebras,
7th Japan-Korea Workshop on Algebra and Combinatorics, 九州大学, 2259室,
2009年8月27日.
Toy models for D. H. Lehmer's conjecture
(joint work with Eiichi Bannai),
「第5回数学総合若手研究集会
―他分野との学際的交流を目指して―
(The 5th Mathematics Conference for Young Researchers)」,
北海道大学学術交流会館, March 4 (Wednesday).
Upper bound for l-modular lattices and its spherical designs,
「Kumjung Seminar in 2009 (satellite seminar of the 6th Korea-Japan Workshop on Algebra and Combinatorics.)」Room C32-208 at Pusan National University, February 11 (Wednesday).
Toy models for D. H. Lehmer's conjecture
(joint work with Tsuyoshi Miezaki),
「Korea-Japan Workshop on Algebra and Combinatorics」Room C32-208 at Pusan National University, February 10 (Tuesday), (speaker is Eiichi Bannai).
On the zeros of certain polynomials related to the extremal vertex operator algebras,
「Algebras, Groups and Geometries 2008」研究集会,東京大学大学院数理科学研究科 一階 大講義室, 2008年12月10, 11日.
On the zeros of certain polynomials associated with the extremal vertex operator algebras,
Mini-workshop in algebraic combinatorics, R204, 2F, NCTS, NCKU, Saturday, Nov. 29, 2008.
On the zeros of certain polynomials associated with the extremal
vertex operator algebras,
第119 回日本数学会九州支部例会, 鹿児島大学理学部101 講義室(理学部1号館1階, 2008年10月18日.
On the Zeros of Hecke Type Faber Polynomials,
Mini-workshop in Algebraic Combinatorics ,Math Science Building room 208, Postech, February 12, 2007.
Hecke 多項式について.,
組合せ論ミニ集会, 九州大学, 2006年3月.
Question and Answer Check System for Mathematics on the Web., Asian Symposium on Computer Mathematics 2005, Korea Institute for Advanced Study (KIAS), (December 2005)(with S. Toyota).
Locations of the zeros of Hecke polynomials associated with the Thompson series of the elements of the Monster ,
6th Symposium on Algebra and Computation (AC2005), Tokyo Metropolitan University (November 2005). (speaker is Eiichi Bannai).
On the zeros of Eisenstein series associated with \Gamma_0^*(2), \Gamma_0^*(3), and some groups(with J. Shigezumi and H. Nozaki)
RIMS Workshop "Algebraic Combinatorics and Related Fields of Research", Research Institute for Mathematical Sciences Kyoto University, October, 2005.
On the Zeros of Eisenstein Series for \Gamma_0^*(2) and \Gamma_0^*(3).,
The Fifth Algebraic Combinatorics Seminar, Pusan National University, (August 2005).
On the zeros of Eisenstein series associated with \Gamma_0^*(2) and \Gamma_0^*(3)(with J. Shigezumi and H. Nozaki)
The Second COE Workshop on Sphere Packing, Kyushu University, June, 2005.
その他の講演
Spherical designs and Conformal designs(ポスターセッション)
組合せ論サマースクール(2009), 稚内北星学園大学, 2009年 9月 2日.
Nonexistence of spherical designs obtained from integer rings
of imaginary quadratic fields(ポスターセッション)
「夏の学校「Designs and Codes」(ヒルズサンピア山形)」2009年 6月21日.
Toy models for D. H. Lehmer's conjecture
東京理科大学理工学部数学科談話会,東京理科大学,2009年 5月.