• Korean Journal of Mathematics
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• v.24 no.3
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• pp.335-344
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• 2016

In this paper, we obtain quantitative estimates for generalized double Baskakov operators. We calculate global results for these operators using Lipschitz-type spaces and estimate the error using modulus of continuity.

• Bulletin of the Korean Mathematical Society
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• v.38 no.1
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• pp.205-210
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• 2001

We give a characterization of regular operators that allows us to prove that a bounded operator acting between Banach spaces is almost regular if and only if it is regular, solving an open problem in [5]. As an application, we show that some operators in the closure of the set of all regular operators are regular.

• Bulletin of the Korean Mathematical Society
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• v.48 no.1
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• pp.141-149
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• 2011

We consider the problem to determine when a Toeplitz operator is bounded on weighted Bergman spaces. We show that Toeplitz operators induced by elements of some set are bounded and each element of the set is related with a Carleson measure on the weighted Bergman space.

• Journal of the Korean Mathematical Society
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• v.48 no.5
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• pp.1053-1063
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• 2011

We discuss the perturbation theory of "left" and "right" Browder operators, which come somewhere between Browder operators and semi Browder operators.

• Korean Journal of Mathematics
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• v.7 no.2
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• pp.271-280
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• 1999

We study Toeplitz operators on the harmonic Bergman Space $b^p(\mathbf{H})$, where $\mathbf{H}$ is the upper half space in $\mathbf{R}(n{\geq}2)$, for 1 < $p$ < ${\infty}$. We give characterizations for the Toeplitz operators with positive symbols to be bounded.

• Honam Mathematical Journal
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• v.42 no.1
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• pp.63-74
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• 2020

In this paper firstly, Some properties were given about metallic Riemannian structure on (1, 1)-tensor bundle. Secondly, the Tachibana and Vishnevskii operators were applied to vertical and horizontal lifts with respect to the metallic Riemannian structure on (1, 1)-tensor bundle, respectively.

• East Asian mathematical journal
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• v.28 no.3
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• pp.321-332
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• 2012

The purpose of the present paper is to investigate some subordination and superordination preserving properties of certain integral operators de ned on the space of meromorphic functions in the puncture open unit disk. The sandwich-type theorems for these integral operators are also presented.

• Kyungpook Mathematical Journal
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• v.53 no.3
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• pp.349-369
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• 2013

The present paper envisages the $q$-analogue of the exponential operators, determined by G. Dattoli and his collaborators for translation and diffusive operators which were utilized to establish analytical solutions of difference and integral equations. The generalization of their technique is expected to cover wide range of such utilization.

• Kyungpook Mathematical Journal
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• v.49 no.2
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• pp.203-209
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• 2009

In this paper we study some spectral properties of the class (y) operators and we will investigate on the relation between this class and other usual classes of operators.

• Journal of the Chungcheong Mathematical Society
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• v.24 no.1
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• pp.65-73
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• 2011

In this note we present some necessary and sufficient conditions for the hyponormality of Toeplitz operators $T_{\varphi}$ under certain assumptions concerning the trigonometric polynomial symbol ${\varphi}$.