• 대한수학회논문집
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• 제4권1호
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• pp.173-185
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• 1989

• 호남수학학술지
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• 제41권1호
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• pp.101-116
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• 2019

In this paper our aim is to establish some geometric properties (like starlikeness, convexity and close-to-convexity) for the generalized and normalized Dini functions. In order to prove our main results, we use some inequalities for ratio of these functions in normalized form and classical result of Fejer.

• Kyungpook Mathematical Journal
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• 제45권1호
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• pp.123-130
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• 2005

In this paper we discuss a class of analytic functions related to the starlike functions in the unit disk. We prove that this class belongs to the class of close-to-convex functions, we obtain the sharp coefficient upper bounds and distortion theorem of this class, we also get the convexity radius of this class.

• 호남수학학술지
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• 제21권1호
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• pp.139-147
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• 1999

In this paper we generalize the definition of strongly close-to-convex functions by using the functions g(z) of bounded boundary rotation and investigate the distortion and rotation theorem, coefficient inequalities, invariance property and inclusion relation for the new class $G_{k}[A,\;B]$.

• 대한수학회논문집
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• 제28권1호
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• pp.143-154
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• 2013

We introduce a subclass $S_s^{({\kappa})}$(A,B) (-1 ${\leq}$ B < A ${\leq}$ 1) of functions which are analytic in the open unit disk and close-to-convex with respect to ${\kappa}$-symmetric points. We give some coefficient inequalities, integral representations and invariance properties of functions belonging to this class.

• Korean Journal of Mathematics
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• 제29권2호
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• pp.395-407
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• 2021

By considering a certain univalent function that maps the unit disk 𝕌 onto a strip domain, we introduce new subclasses of analytic and p-valent functions and determine the coefficient bounds for functions belonging to these new classes. Relevant connections of some of the results obtained with those in earlier works are also provided.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제10권4호
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• pp.265-271
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• 2003

Let $CS_\alpha(\beta)$ denote the class of normalized strongly $\alpha$-close-to-convex functions of order $\beta$, defined in the open unit disk $\cal{U}$ of $\mathbb{C}$${\mid}arg{(1-{\alpha})\frac{f(z)}{g(z)}+{\alpha}\frac{zf'(z)}{g(z)}}{\mid}\;\leq\frac{\pi}{2}{\beta}(\alpha,\beta\geq0)$ such that $g\; \in\;S^{\ask}$, the class of normalized starlike unctions. In this paper, we obtain the sharp Fekete-Szego inequalities for functions belonging to $CS_\alpha(\beta)$.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제3권2호
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• pp.103-111
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• 1996

Let $f(z)=z＋\alpha_2 z^2$＋…＋ \alpha_{n}z^n$＋… be regular and univalent in $\Delta$ = {z : │z│＜1}. In this paper, using the proper subordinate functions, we investigate the some relations between subordinations and conditions of functions belonging to subclasses of univalent functions.

• 대한수학회보
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• 제35권3호
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• pp.571-582
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• 1998

The object of the present paper is to derive some sufficient conditions for p-valently close-to-convexity, p-valently starlikeness and p-valently convexity.

• Journal of applied mathematics & informatics
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• 제39권1_2호
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• pp.133-143
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• 2021

The purpose of this paper is to introduce and study certain subclasses of analytic functions by using Ruscheweyh derivative operator. We discuss various of interesting properties such as, necessary condition, arc length problem and growth rate of coefficient of newly defined class. Also rate of growth of Hankel determinant will be estimated.