arXiv subjects

Daeshik Choi

Publications and source records attributed to Daeshik Choi.

2 recordsLinked to original sources

arXiv2016

Improved Jensen-type inequalities via linear interpolation and applications

In this paper we develop a general method for improving Jensen-type inequalities for convex and, even more generally, for piecewise convex functions. Our main result relies on the linear interpolation of a convex function. As a consequence, we obtain improvements of some recently established Young-type inequalities. Finally, our method is also applied to matrix case. In such a way we obtain improvements of some important matrix inequalities known from the literature.

math.CA↗

arXiv2012

A sharp bound on the convergence rate of an aggregation-based algebraic multi-grid method applied to a 1D model problem

We consider the linear system Ax=b arising from one-dimensional Poisson's equation with Dirichlet boundary conditions, where A is the square matrix with the stencil form [-1 2 -1]. Here we show that a pairwise aggregation-based algebraic 2-grid method reduces the A-norm of the error at each step by at least the factor $1/\sqrt{2}$.

math.NA↗