• Journal of the Korean Mathematical Society
• /
• v.33 no.2
• /
• pp.333-346
• /
• 1996

Let $A(\zeta, \partial)$ be a second order uniformly elliptic operator $$ A(\zeta, \partial )u = -\sum_{j, k = 1}^{n} \frac{\partial\zeta_i}{\partial}(a_{jk}(\zeta)\frac{\partial\zeta_k}{\partial u}) + \sum_{j = 1}^{n}b_j(\zeta)\frac{\partial\zeta_j}{\partial u} + c(\zeta)u $$ with real, smooth coefficients $a_{j, k}, b_j$, c defined on $\zeta \in \Omega, \Omega$ a bounded domain in $R^n$ with a sufficiently smooth boundary $\Gamma$.

• Bulletin of the Korean Mathematical Society
• /
• v.51 no.4
• /
• pp.1195-1204
• /
• 2014

We newly define the volume integral means of harmonic functions to characterize the weighted harmonic Bergman spaces. It is based on Xiao and Zhu's results on holomorphic Bergman spaces [5].

• Bulletin of the Korean Mathematical Society
• /
• v.44 no.2
• /
• pp.369-378
• /
• 2007

We classify all semigroups each of which arises as a Weierstrass semigroup at a pair of inflection points of multiplicities d or d-1 on a smooth plane curve of degree d.

• Bulletin of the Korean Mathematical Society
• /
• v.54 no.2
• /
• pp.667-677
• /
• 2017

Let $F{\subseteq}{\mathbb{P}}^3$ be a smooth surface of degree $3{\leq}d{\leq}9$ whose equation can be expressed as either the determinant of a $d{\times}d$ matrix of linear forms, or the pfaffian of a $(2d){\times}(2d)$ matrix of linear forms. In this paper we show that F supports families of dimension p of pairwise non-isomorphic, indecomposable, Ulrich bundles for arbitrary large p.

• Communications of the Korean Mathematical Society
• /
• v.33 no.3
• /
• pp.823-831
• /
• 2018

We define progressive tax rate functions, study their properties, and describe some smooth models. The key requirement, defining the progressive nature of the taxation model, is that the progressive tax rate functions should have infinite contact with the zero function at the origin, in order to care the poor. In constructing a wide array of such functions, assisting functions are introduced.

• Bulletin of the Korean Mathematical Society
• /
• v.45 no.4
• /
• pp.635-644
• /
• 2008

In this paper, we prove that the equivalence between the convergence of Mann and Ishikawa iterations for the generalized Lipschitzian and $\Phi$-strongly pseudocontractive mappings in real uniformly smooth Banach spaces. Our results significantly generalize the recent known results of [B. E. Rhoades and S. M. Soltuz, The equivalence of Mann iteration and Ishikawa iteration for non-Lipschitz operators, Int. J. Math. Math. Sci. 42 (2003), 2645.2651].

• Korean Journal of Mathematics
• /
• v.25 no.1
• /
• pp.1-18
• /
• 2017

In this paper, we introduce the concepts of ([r, s], [t, u])-interval-valued intuitionistic fuzzy generalized preclosed sets and ([r, s], [t, u])-interval-valued intuitionistic fuzzy generalized preopen sets in the interval-valued intuitionistic smooth topological space and ([r, s], [t, u])-interval-valued intuitionistic fuzzy generalized pre-continuous mappings and then investigate some of their properties.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.557-560
• /
• 2005

This paper considers a global asymptotic output tracking problem with a prescribed constant reference signal for a class of single-input and single output-output nonlinear systems. It is shown that under some mild conditions on such a system there is a smooth output feedback achieving global asymptotic output tracking and such a smooth output controller is explicitly constructed by a new design method proposed. The usefulness of our result is illustrated by a numerical example.

• Proceedings of the Korea Environmental Mutagen Society Conference
• /
• 2004.11a
• /
• pp.119-119
• /
• 2004

• Journal of the Korean Institute of Intelligent Systems
• /
• v.12 no.3
• /
• pp.269-274
• /
• 2002

We introduce (${\tau}_i$, ${\tau}_j$) fuzzy (r,s)-semiclosures and (${\tau}_i$, ${\tau}_j$)-fuzzy (r,s)-semiinteriors. Using the notions, we investigate some of characteristic properties of fuzzy pairwise (r,s)-semicontinuous, fuzzy pairwise (r,s)-semiopen and fuzzy pairwise (r,s)-semiclosed mappings.