Ibaraki University's
College of Education
Teacher Training Course (Mathematics Education)


UMEZU kenichiro


  1. 筑波大学数学系準研究員(文部技官) 1993/06/16-1997/02/28
  2. 筑波大学数学系助手 1997/03/01-1997/03/31
  3. 前橋工科大学工学部講師 1997/04/01-2001/03/31
  4. 前橋工科大学工学部助教授 2001/04/01-2007/03/31
  5. 前橋工科大学工学部准教授 2007/04/01-2008/03/31
  6. 茨城大学教育学部准教授 2008/04/01-2012/03/31
  7. 茨城大学教育学部教授 2012/04/01-Present

Academic background

  1. University of Tsukuba First Cluster of College College of Natural Sciences 1988/03 Graduated
  2. University of Tsukuba Graduate School, Division of Mathematics Doctor course 1993/03 Completed

Academic degrees

  1. Doctor of Mathematics University of Tsukuba 1993/03

Research Areas

  1. Basic Analysis

Research keywords

  1. 非線形楕円型境界値問題,非線型境界条件,concave-convex 非線形性,変分法,固有値問題,符号不定係数,分岐理論,写像度,位相的手法,人口動態論.

Subject of research

  1. 半線形楕円型境界値問題の正値解集合の構造について 1995-Present


  1. Research paper (scientific journal) Joint Loop type subcontinua of positive solutions for indefinite concave-convex problems Uriel Kaufmann, Humberto Ramos Quoirin, Kenichiro Umezu Advanced Nonlinear Studies published online 2018 10.1515/ans-2018-2027
  2. Research paper (scientific journal) Joint Positive solutions of an elliptic Neumann problem with a sublinear indefinite nonlinearity Uriel Kaufmann, Humberto Ramos Quoirin, Kenichiro Umezu Nonlinear Differential Equations and Applications NoDEA 25:12 2018 10.1007/s00030-018-0502-1
  3. Research paper (scientific journal) Joint A loop type component in the non-negative solutions set of an indefinite elliptic problem Humberto Ramos Quoirin, Kenichiro Umezu Communications on Pure and Applied Analysis 17/ 3, 1255-1269 2018 10.3934/cpaa.2018060
  4. Research paper (scientific journal) Joint Positivity results for indefinite sublinear elliptic problems via a continuity argument Uriel Kaufmann, Humberto Ramos Quoirin, Kenichiro Umezu Journal of Differential Equations 263/ 8, 4481-4502 2017 10.1016/j.jde.2017.05.021
  5. Research paper (scientific journal) Joint An indefinite concave-convex equation under a Neumann boundary condition II Humberto Ramos Quoirin, Kenichiro Umezu Topological Methods in Nonlinear Analysis 49/ 2, 739-756 2017 10.12775/TMNA.2017.007

Research presentations

  1. Oral presentation(invited, special) Positivity of bifurcating nontrivial nonnegative solutions of indefinite concave problems The 12th AIMS Conference on Dynamical Systems, Differential Equations and Applications in Taipei 2018/07/06
  2. Oral presentation(general) Loop components of nontrivial nonnegative solutions for indefinite concave-convex problems 日本数学会2018年年会函数方程式論分科会 2018/03/18
  3. Oral presentation(invited, special) concave-convex タイプの非線形楕円型境界値問題に対するループ型有界連続体解集合の存在について 首都大学東京・変分問題セミナー 2017/12/14
  4. Oral presentation(general) Positivity for nontrivial nonnegative solutions of an indefinite sublinear problem 日本数学会2017年年会函数方程式論分科会 2017/03/24
  5. Oral presentation(invited, special) On the existence of a loop component of nontrivial non-negative solutions for some concave-convex problem Workshop on reaction diffusion equations and numerical analysis 2016/10/08


  1. The ISAAC Award for Young Scientists 2003/08 URL http://isaacmath.org/awards/2003/

Memberships of academic societies

  1. 日本数学会
  2. 日本応用数理学会