• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.475-484
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• 2005

The main aim of this paper is to consider the fuzzy norm, define the fuzzy Banach spaces, its quotients and prove some theoremes and in particular Open mapping and Closed graph theoremes on these spaces.

• Journal of the Korean Mathematical Society
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• v.35 no.2
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• pp.295-314
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• 1998

In this article we examine certain distinctive features regarding Hardy spaces of both classical and product notions on $R^{N}$ with our focus on their interrelations through embeddings and restrictions. Applications of our results to multiple singular integrals are included.d.

• Communications of the Korean Mathematical Society
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• v.21 no.4
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• pp.719-727
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• 2006

In this paper, we study the boundedness and the com-pactness of weighted composition operator between $H^{\infty}$ and Bergman type space on the unit ball of $\mathbb{C}^n$. Also, the norm of corresponding weighted composition operator is computed.

• Korean Journal of Mathematics
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• v.4 no.2
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• pp.125-133
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• 1996

We show that if X is a reflexive Banach space with a uniformly G$\hat{a}$teaux differentiable norm, then the convergence of semigroups acting on Banach spaces $X_n$ implies the convergence of resolvents of generators of semigroups.

• Journal of applied mathematics & informatics
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• v.5 no.2
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• pp.449-456
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• 1998

In this paper a new type of t-operators with double threshold a,b,$\in$(0,1). a$\leq$b, is presented, each pair (t-norm, t-conorm) consisting of two dual elements with respect to a negation with double threshold.

• Korean Journal of Mathematics
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• v.5 no.2
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• pp.127-134
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• 1997

On the setting of the upper half-space of the euclidean n-space, we study some properties of harmonic little Bloch functions and we show that for a given harmonic little Bloch function $u$, there exists unique harmonic conjugates of $u$, which are also little Bloch functions with appropriate norm bounds.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.29-32
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• 2002

We consider the question whether, for given fuzzy numbers, there are different Pairs of f-norm such that the resulting membership function within the extension principle under addition are identical. Some examples are given.

• Journal of the Chungcheong Mathematical Society
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• v.24 no.4
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• pp.833-842
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• 2011

We prove that Toeplitz operators with symbols in RW are bounded and we calculate some upper bounds of the norm of these Toeplitz operators. We also analyze n-th derivative of Toeplitz operators and get some local estimates.

• Bulletin of the Korean Mathematical Society
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• v.56 no.5
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• pp.1341-1353
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• 2019

For complete Riemannian manifolds with vanishing Bach tensor and positive constant scalar curvature, we provide a rigidity theorem characterized by some pointwise inequalities. Furthermore, we prove some rigidity results under an inequality involving $L^{\frac{n}{2}}$-norm of the Weyl curvature, the traceless Ricci curvature and the Sobolev constant.

• Bulletin of the Korean Mathematical Society
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• v.58 no.4
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• pp.877-884
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• 2021

We prove that if a compact convex hypersurface of ℝⁿ⁺¹ has almost maximal extinction time when it is evolved by the mean curvature flow, then it must be nearly round in the C⁰-norm.