Hirokazu OKAProfessor
■Researcher basic information
Organization
Career
- Apr. 2018, 茨城大学大学院 理工学研究科工学野, 教授
- Apr. 2009, Collegue of Engineering, Ibaraki University, Professor
- Apr. 2007, College of Engineering, Ibaraki University, 准教授
- Apr. 2004, Ibaraki University Faculty of Engineering, Assistant Professor
- Apr. 1996, College of Engineering, Ibaraki University, Lecturer
- Apr. 1993 - Mar. 1995, Department of Mathematics, School of Education, Waseda University, Research Associate
Message from Researchers
(Message from Researchers)
(研究経歴)
Nonlinear ergodic theorems, Volterra integrodifferential equations
■Research activity information
Paper
- Ordered continuous bands on the positive real numbers and distribution
H. Oka; T Miura; N. Niwa and S.-E. Takahasi, Lead
Publ. Math. Debrecen, 08 May 2023, [Reviewed] - Special noncancellative commutative semigroup operations on the real numbers and distribution
T. Miura; N. Niwa; H. Oka and S.-E. Takahasi, Corresponding
Acta Math. Hungar., 22 Dec. 2022, [Reviewed] - Evolution equations governed by quasilinear operators satisfying Caratheodory's conditions
Toshitaka Matsumoto; Hirokazu Oka; Naoki Tanaka
Dissertationes Mathematicae, 02 Feb. 2022, [Reviewed] - A special noncommutative semigroup operation on the real numbers and left or right distribution
Takeshi Miura; Norio Niwa; Hirokazu Oka; Sin-Ei Takahasi, Corresponding
Results in Mathematics, 12 Jan. 2022, [Reviewed] - Semigroup operations which are distributive over a given semigroup operation on positive real numbers
Hirokazu Oka; Takeshi Miura; Sin-Ei Takahasi, Lead, Springer
Acta Scientiarum Mathematicarum (Szeged), 22 Aug. 2020, [Reviewed] - Semigroup operations distributed by natural noncancellative semigroup operations on the positive real numbers
Hirokazu Oka; Takeshi Miura and Sin-Ei Takahasi, Lead, Springer
Semigroup Forum, 09 Aug. 2020, [Reviewed] - Characterization of distributive semigroup operations on the positive real numbers
S.-E. Takahasi; T. Miura and H. Oka, Corresponding, Springer
Semigroup Forum, 22 Mar. 2020, [Reviewed] - Semigroup operations distributed by the ordinary multiplication or addition on the real numbers
Sin-Ei Takahasi; Hiroyuki Takagi; Takeshi Miura; Hirokazu Oka
PUBLICATIONES MATHEMATICAE-DEBRECEN, 2017, [Reviewed] - Global solvability for abstract semilinear evolution equations.
Hirokazu Oka and Naoki Tanaka
Math. Nachr., 2010, [Reviewed] - A polynomially spectrum preserving map between uniform algebras.
Go Hirasawa and Hirokazu Oka
Nihonkai Math. J., 2010, [Reviewed] - Stability of almost multiplicative functionals
Norio Niwa; Takeshi Miura; Hirokazu Oka; Sin-Ei Takahasi
Aust. J. Math. Anal. Appl., 04 Sep. 2009, [Reviewed] - Peripheral multiplicativity of maps on uniformly closed algebras of continuous functions which vanish at infinity
O.Hatori; T.Miura; H.Oka; H.Takagi
Tokyo J. Math., Jun. 2009, [Reviewed] - Peripherally Monomial-Preserving Maps between Uniform Algebras
Osamu Hatori; Kazumi Hino; Takeshi Miura; Hirokazu Oka
Mediterr. J. Math., 2009, [Reviewed] - A Cauchy-Euler Type Factorization of Operators
Sin-Ei Takahasi; Hirokazu Oka; Takeshi Miura and Hiroyuki Takagi
Tokyo J. Math., Dec. 2008, [Reviewed] - On surjective ring homomorphisms between semi-simple,commutative Banach algebras
Takeshi Miura; Sin-Ei Takahasi; Norio Niwa and Hirokazu Oka
Publ. Math. Debrecen, Jul. 2008, [Reviewed] - A Cauchy-Euler Type Factorization of Operators
Sin-Ei Takahasi; Hirokazu Oka; Takeshi Miura; Hiroyuki Takagi
Tokyo Journal of Mathematics, 2008, [Reviewed] - Ger type stability of the first order linear differential equation y'(t)=h(t)y(t).
Tamsui Oxf. J. Math. Sci., 2008, [Reviewed] - 2-Local Isometries and 2-Local Automorphisms on Uniform Algebras
Osamu Hatori; Takeshi Miura; Hirokazu Oka; Hiroyuki Takagi
International Mathematical Forum, 2007, [Reviewed] - Superstability of multipliers and ring derivations on Banach algebras
Takeshi Miura; Hirokazu; Oka; Go; Hirasawa; Sin-Ei Takahasi
Banach J. Math. Anal., 2007, [Reviewed] - An example of multiplicatively spectrum-preserving maps between non-isomorphic semi-simple commutative Banach algebras
Osamu Hatori; Takeshi Miura and Hirokazu Oka, Niigata University
Nihonkai Mathematical Journal, 2007, [Reviewed] - Hyers-Ulam stability of the first order linear differential equation for Banach space-valued holomorphic mappings
Takeshi Miura; Hirokazu Oka; Sin-Ei Takahasi; Norio Niwa
J. Math. Inequal., 2007, [Reviewed] - Evolution operators genereted by non-densely defined operators
Hirokazu Oka; Naoki Tanaka
Math. Nachr., Aug. 2005 - On the structure of the solution set of a third kind boundary value problem
Sin-ei Takahasi; Hirokazu Oka; Takeshi Miura
Math. Nachr., Jul. 2003
MISC
Books and other publications
Lectures, oral presentations, etc.
Social Contribution Activities
- Peer review of overseas academic journal articles
others
The Jounal of Analysis, 10 Aug. 2024 - 12 Jan. 2025 - 海外の学術雑誌の論文の査読
others
14 Jul. 2020 - 15 Sep. 2020 - 海外の学術雑誌の論文の査読
others
14 Nov. 2019 - 04 Dec. 2019 - 日本学術振興会 特別研究員等審査会専門委員（書面審査担当）
others
01 Jul. 2018 - 30 Jun. 2019 - 海外の学術雑誌の論文の査読
others
Springer Journals Editorial Office,Bulletin of the Malaysian Mathematical Sciences Society, 17 Apr. 2019 - 12 Jun. 2019
Academic Contribution Activities
