主な講演(2000年以降)
 Complex cobordism ring, boson Fock space and KP hierarchy,
The Eleventh International Colloquium on Differential Equations,
Plovdiv, Bulgaria, August 20, 2000.
 On L\”{u}roth’s theorem, Colloquium,
Univ. of Amsterdam, The Netherlands, September 27, 2000.
 On the number of principally polarized superspecial abelian varieties over ${\bf F}_{p}$,
Algebraic Geometry Seminar,
Univ. of Amsterdam, The Netherlands, October 16, 2000.
 On Fermat varieties,
Algebraic Geometry Seminar,
Univ. of Amsterdam, The Netherlands, October 16, 2001.
 符号・暗号理論と正標数の代数幾何学,
日本数学会年会企画特別講演,
明治大学駿河台キャンパス, 2002年3月31日.
 Invariants of algebraic varieties in positive characteristic,
Special Year on Algebraic Geometry and Topology,
Australian National Univ., Australia, August 25, 2003.
 正標数のCalabiYau多様体とArtinMazur形式群,
代数幾何学シンポジウム,
東北大学, 2003年3月13日.
 正標数ワールド,
第48回代数学シンポジウム,
名古屋大学, 2003年8月4 日.
 代数幾何学と分類理論,
日本応用数理学会総合講演,
京都大学吉田キャンパス, 2003年9月18日.
 On a stratification of the moduli of K3 surfaces in positive characteristic,
International Conference on Arithmetic Geometry,
Euler International Mathematical Institute, St. Petersburg, Russia, June 25, 2004.
 On a stratification of moduli of K3 surfaces,
KoreaJapan Conference on Algebraic Geometry,
KIAS, Korea, July 6, 2004.
 Unirational surfaces in positive characteristic,
Current Trends in Mathematics Number Fields and Curves over Finite Fields,
Anogia, Greece, July 24, 2005.
 On the distribution of linear codes,
Algebraic Geometry and Beyond,
RIMS, December 15, 2005.
 Automorphism group of abelian surfaces and the unirationality of generalized Kummer surfaces in positive characteristic,
Workshop of Abelian Varieties,
Univ. of Amsterdam, The Netherlands, May 30, 2006.
 Introduction to coding theory,
July 15 and 16; On the unirationality of Fermat varieties,
July 18 and 19, School of Characteristic p Method in Algebraic Geometry,
Drobeta TurnuSeverin, Romania, 2007.
 From genus 2 to genus 3,
Conference on Explicit Structures in Modular Forms and Number Theory,
Kinki Univ., September 7, 2008.
 Some remarks on invariants of algebraic varieties in positive characterisitic,
International Conference on Arithmetic and Algebraic Geometry,
Univ. of Tokyo, July 4, 2008.
 On the structure of cohomology groups of K3 surfaces in positive characteristic,
Algebraic Geometry in Characteristic p and Related Topics,
Univ. of Tokyo, February 16, 2010.
 Invariants of algebraic varieties in positive characteristic,
KIAS Seminar,
Seoul, Korea, March 29, 2010.
 Some invariants of algebraic varieties in positive characteristic,
Prospects in Mathematics,
Trento Univ. (CIRM), Italy, September 14, 2010.
 On the configuration of rational curves on the supersingular K3 surfaces in small characteristics,
Geometry and Arithmetic,
Schiermonnikoog, The Netherlands, September 23, 2010.
 Configurations of rational curves on the supersingular K3 surface with Artin invariant 1 in characteristic 3,
Workshop on Algebraic Geometry in Positive Characteristic,
KIAS, Seoul, Korea, May 26, 2011.

