• East Asian mathematical journal
• /
• v.24 no.2
• /
• pp.201-212
• /
• 2008

We characterize operators between Banach spaces sending unconditionally weakly p-summable sequences into sequences that lie in the range of a vector measure of bounded variation. Further, we describe operators between Banach spaces taking unconditionally weakly p-summable sequences into sequences that lie in the range of a vector measure.

• Honam Mathematical Journal
• /
• v.25 no.1
• /
• pp.75-82
• /
• 2003

In this note it is shown that if T satisfies ($G_{1}$)-condition with finite spectrum then Weyl's theorem holds for T. If T is totally *-paranormal then $T-{\lambda}$ has finite ascent for all ${\lambda}{\in}{\mathbb{C}},\;T$ is isoloid, and Weyl's theorem holds for T.

• Journal of the Chungcheong Mathematical Society
• /
• v.22 no.2
• /
• pp.271-279
• /
• 2009

In this paper, we prove that asymptotically quasisimilar sub-decomposable operators have equal spectra and quasisimilar decomposable operators have equal spectra. Moreover, every subscalar operator is admissible.

• Communications of the Korean Mathematical Society
• /
• v.19 no.3
• /
• pp.435-452
• /
• 2004

In this paper, we prove the weighted continuity of multilinear Marcinkiewicz operators for the extreme cases of p.

• Bulletin of the Korean Mathematical Society
• /
• v.54 no.5
• /
• pp.1669-1675
• /
• 2017

The group of automorphisms of the first Weyl algebra acts on commuting ordinary differential operators with polynomial coefficient. In this paper we prove that for fixed generic spectral curve of genus two the set of orbits is infinite.

• Bulletin of the Korean Mathematical Society
• /
• v.54 no.3
• /
• pp.715-729
• /
• 2017

In this paper, we investigate the existence and multiplicity of solutions for systems driven by two non-local integrodifferential operators with homogeneous Dirichlet boundary conditions. The main tools are the Saddle point theorem, Ekeland's variational principle and the Mountain pass theorem.

• Communications of the Korean Mathematical Society
• /
• v.17 no.3
• /
• pp.423-430
• /
• 2002

The object of this Paper is to Present a q-analogue of the Newton's forward-difference interpolation formula. We relate the q-beta function and the q-gamma function by the q-difference operators.

• Journal of the Korean Mathematical Society
• /
• v.46 no.1
• /
• pp.83-97
• /
• 2009

Two new iterative algorithms are provided to find zeros of accretive operators in a Banach space E with a uniformly $G\hat{a}teaux$ differentiable norm. Strong convergence for two iterations is proved and as applications, the viscosity approximation results are obtained also.

• Kyungpook Mathematical Journal
• /
• v.51 no.1
• /
• pp.87-91
• /
• 2011

In this paper we obtain a Voronvskaya type theorem for modi ed Post-Widde operators.

• Journal of the Chungcheong Mathematical Society
• /
• v.21 no.2
• /
• pp.287-292
• /
• 2008

We introduce jointly weak subnormal operators. It is shown that if $T=(T_1,T_2)$ is subnormal then T is weakly subnormal and if f $T=(T_1,T_2)$ is weakly subnormal then T is hyponormal. We discuss the flatness of weak subnormal operators.