• 대한수학회논문집
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• 제22권3호
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• pp.373-382
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• 2007

In this paper, we characterize the boundedness and compactness of weighted composition operators ${\psi}C{\varphi}f=\psi(f^{\circ}\varphi)$ acting between Bergman and Bloch spaces of holomorphic functions on the open unit disk D.

• 대한수학회논문집
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• 제33권2호
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• pp.437-444
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• 2018

Let S denote the class of analytic and univalent functions in the open unit disk $D=\{z:{\mid}z{\mid}<1\}$ with the normalization conditions f(0) = 0 and f'(0) = 1. In the present article, an upper bound for third order Hankel determinant $H_3(1)$ is obtained for a certain subclass of univalent functions generated by Ruscheweyh derivative operator.

• 대한수학회논문집
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• 제35권3호
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• pp.789-797
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• 2020

By considering a certain univalent function in the open unit disk 𝕌, that maps 𝕌 onto a strip domain, we introduce a new class of analytic and close-to-convex functions by means of a certain non-homogeneous Cauchy-Euler-type differential equation. We determine the coefficient bounds for functions in this new class. Relevant connections of some of the results obtained with those in earlier works are also provided.

• 대한수학회논문집
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• 제35권3호
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• pp.867-877
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• 2020

The aim of this article is to make a connection between the Pascal distribution series and some subclasses of normalized analytic functions whose coefficients are probabilities of the Pascal distribution. To be more precise, we investigate such connections with the classes of analytic univalent functions with positive coefficients in the open unit disk 𝕌.

• 대한수학회보
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• 제32권2호
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• pp.201-204
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• 1995

Let N be the class of functions of the form $$ (1.1) p(z) = 1 + p_1 z + p_2 z^2 + \cdots $$ which are analytic in the open unit disk $U = {z : $\mid$z$\mid$ < 1}$. If $p(z) \in N$ satisfies $Rep(z) > 0 (z \in U)$, then p(z) is called a Caratheodory function (cf. Goodman [2]).

• 대한수학회보
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• 제46권5호
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• pp.905-915
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• 2009

Making use of a generalized differential operator we introduce some new subclasses of multivalent analytic functions in the open unit disk and investigate their inclusion relationships. Some integral preserving properties of these subclasses are also discussed.

• 대한수학회지
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• 제45권3호
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• pp.611-620
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• 2008

The purpose of this present paper is to derive some subordination and superordination results involving Carlson-Shaffer operator for certain normalized analytic functions in the open unit disk. Relevant connections of the results, which are presented in the paper, with various known results are also considered.

• 대한수학회지
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• 제51권3호
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• pp.567-592
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• 2014

Complex-valued harmonic functions that are univalent and sense-preserving in the open unit disk are widely studied. A new methodology is employed to construct subclasses of univalent harmonic mappings from a given subfamily of univalent analytic functions. The notions of harmonic Alexander operator and harmonic Libera operator are introduced and their properties are investigated.

• 대한수학회보
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• 제51권3호
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• pp.803-812
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• 2014

Let ${\mathcal{S}}^0_{\mathcal{H}}$ be the class of normalized univalent harmonic mappings in the unit disk. A subclass ${\mathcal{V}}^{\mathcal{H}}(k)$ of ${\mathcal{S}}^0_{\mathcal{H}}$, whose analytic part is function with bounded boundary rotation, is introduced. Some bounds for functionals, specially harmonic pre-Schwarzian derivative, described in ${\mathcal{V}}^{\mathcal{H}}(k)$ are given.

• 대한수학회보
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• 제38권2호
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• pp.357-367
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• 2001

Let $Q(\beta)$ be the class of normalized strongly quasiconvex functions of order $\beta$ in the open unit disk. Sharp Fekete-Szego inequalities are obtained for functions belonging to the class $Q(\beta)$. We also consider the integral preserving properties in a sector.