J-GLOBAL         Last updated: Mar 29, 2019 at 02:45
Waseda University
Faculty of Science and Engineering Waseda Research Institute for Science and Engineering
Job title
Junior Researcher(Assistant Professor)
Research funding number

Research Interests


Research Areas



Graduate School, Division of Mathematical Sciences, University of Tokyo

Awards & Honors

Sep 2015
Hybridized discontinuous Galerkin method with lifting operator (JSIAM LettersVol.2 (2010) pp.99-102), Best paper award (JSIAM Letters), Japan Society for Industrial and Applied Mathnematics
Winner: Issei Oikawa
Jun 2014
JSIAM Young Scientist Presentation Award, Japan Society for Industrial and Applied Mathematics
Winner: Issei Oikawa

Published Papers

Oikawa, Issei
Journal of Scientific Computing   1-11   Jan 2018
© 2018 Springer Science+Business Media, LLC, part of Springer Nature We propose and analyze a new hybridizable discontinuous Galerkin (HDG) method for second-order elliptic problems. Our method is obtained by inserting the (Formula presented.)-ort...
Zhou, Guanyu; Kashiwabara, Takahito; Oikawa, Issei
Applications of Mathematics   62(4) 377-403   Aug 2017
© 2017, Institute of Mathematics of the Academy of Sciences of the Czech Republic, Praha, Czech Republic. We consider the finite element method for the time-dependent Stokes problem with the slip boundary condition in a smooth domain. To avoid a v...
Oikawa, Issei
Journal of Scientific Computing   67(2) 475-492   May 2016   [Refereed]
© 2015, Springer Science+Business Media New York. In this paper, we analyze a hybridized discontinuous Galerkin method with reduced stabilization for the Stokes equations. The reduced stabilization enables us to reduce the number of facet unknowns...
Kashiwabara, Takahito; Oikawa, Issei; Zhou, Guanyu
Numerische Mathematik   1-36   Jan 2016   [Refereed]
© 2016 Springer-Verlag Berlin Heidelberg We consider the P1/P1 or P1b/P1 finite element approximations to the Stokes equations in a bounded smooth domain subject to the slip boundary condition. A penalty method is applied to address the essential ...
Kashiwabara, Takahito;Oikawa, Issei;Zhou, Guanyu
NUMERISCHE MATHEMATIK   134(4) 705-740   2016

Research Grants & Projects

What is ``good" shape of elements in FEM
Project Year: Apr 2015 - Mar 2017
The finite element method is a fundamental technology and its validity is guaranteed by the mathematical theory. In particular, regarding the shape of elements and the mathematical properties of finite element solutions, various things are known b...
Development of the hybridized discontinuous method and its mathematical analysis
Project Year: Apr 2014 - Mar 2017
We developed and analyzed reduced-order hybridized discontinuous Galerkin (HDG) methods for Poission's equation and the Stokes equations. The proposed method is obtained by introducing the L2-orthogonal projection onto the finite element space of ...