• Journal of applied mathematics & informatics
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• v.7 no.3
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• pp.959-968
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• 2000

The existence of the operator-valued Feynman integral was established when a Wiener functional is given by a Fourier transform of complex Borel measure [1]. In this paper, I investigate a stability of the Feynman integral with respect to the potentials.

• Communications of the Korean Mathematical Society
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• v.22 no.2
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• pp.259-275
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• 2007

The continuity for the multilinear operators associated to some non-convolution type integral operators on Besov spaces are obtained. The operators include Littlewood-Paley operators, Marcinkiewicz operators and Bochner-Riesz operator.

• East Asian mathematical journal
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• v.23 no.1
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• pp.37-43
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• 2007

We study a maximal operator defined on spaces of homogeneous type, and we prove that this operator is of weak type (1,1). As a consequence we show that the maximal operator belongs to the Muckenhoupt's class $A_1$.

• Communications of the Korean Mathematical Society
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• v.17 no.3
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• pp.531-534
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• 2002

We prove that the star operator and the sequential closure operator on a weakly first countable space are the same and show that the Frechetness is a sufficient condition for a weakly first countable space to be first countable.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.2
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• pp.137-140
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• 2009

In this paper, we introduce and formulate the definitions of Banach operator type k and Banach operator pair on intuitionistic fuzzy metric space. Thereafter we prove some properties and theorems on intuitionistic fuzzy metric space.

• Communications of the Korean Mathematical Society
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• v.34 no.2
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• pp.533-542
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• 2019

We study commutants of Toeplitz operators acting on the Dirichlet space of the unit disk and prove that an operator in the Toeplitz algebra commuting with a Toeplitz operator with a nonconstant polynomial symbol must be a Toeplitz operator with an analytic symbol.

• Journal of the Korean Mathematical Society
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• v.58 no.2
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• pp.473-486
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• 2021

We prove non-existence of real hypersurfaces with Killing structure Jacobi operator in complex projective spaces. We also classify real hypersurfaces in complex projective spaces whose structure Jacobi operator is Killing with respect to the k-th generalized Tanaka-Webster connection.

• Communications of the Korean Mathematical Society
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• v.37 no.2
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• pp.567-574
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• 2022

We use convolution techniques to define certain classes of starlike functions which are associated with Lommel operator. Some inclusion results are investigated. It is also shown that these classes are invariant under Bernardi integral operator.

• Korean Journal of Mathematics
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• v.30 no.2
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• pp.305-313
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• 2022

In this paper we consider a modified version of Smirnov operator and obtain some Bernstein-type inequalities preserved by this operator. In particular, we prove some results which in turn provide the compact generalizations of some well-known inequalities for polynomials.

• Korean Journal of Mathematics
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• v.31 no.1
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• pp.55-61
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• 2023

In this paper we establish a generalization of a result recently proved by Ganenkova and Starkov [J. Math. Anal. Appl., 476 (2019), 696-714] concerning a modified version of Smirnov operator.