• 호남수학학술지
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• 제38권3호
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• pp.495-506
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• 2016

In this paper, we introduce and investigate a new subclass of meromorphic functions associated with a certain integral operator on Hilbert space. For this class, we obtain several properties like the coefficient inequality, extreme points, radii of close-to-convexity, starlikeness and meromorphically convexity and integral transformation. Further, it is shown that this class is closed under convex linear combination.

• 호남수학학술지
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• 제39권3호
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• pp.331-347
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• 2017

The aim of the present paper is to introduce a new subclass of meromorphic functions with positive coefficients defined by a certain integral operator and a necessary and sufficient condition for a function f to be in this class. We obtain coefficient inequality, meromorphically radii of close-to-convexity, starlikeness and convexity, convex linear combinations, Hadamard product and integral transformation for the functions f in this class.

• Korean Journal of Mathematics
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• 제27권4호
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• pp.899-927
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• 2019

In this paper we establish some results depending on the comparative growth properties of composite entire and meromorphic functions using relative (p, q)-th order and relative (p, q)-th lower order where p, q are any two positive integers and that of a special type of differential polynomial generated by one of the factors.

• Journal of applied mathematics & informatics
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• 제36권1_2호
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• pp.121-133
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• 2018

The purpose of the paper is to study the meromorphic functions sharing a nonzero polynomial with finite weight. The results of the paper improve and generalize the recent results due to Pulak Sahoo and Sajahan Seikh [9].

• Kyungpook Mathematical Journal
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• 제48권3호
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• pp.419-431
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• 2008

In this paper, we deal with the problem of meromorphic functions that have three weighted sharing values, and obtain some uniqueness theorems which improve those given by N. Terglane, Hong-Xun Yi & Xiao-Min Li, and others. Some examples are provided to show that the results in this paper are best possible.

• 대한수학회보
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• 제52권1호
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• pp.13-33
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• 2015

In this paper, we study the uniqueness problems of entire or meromorphic functions concerning differential polynomials that share one value with multiplicity using weighted sharing method. We prove two main theorems which generalize and improve the results of Fang and Fang [2], Dyavanal [1] and others and also solve the open problem posed by Dyavanal. This method yields some new results.

• 대한수학회보
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• 제57권5호
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• pp.1307-1317
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• 2020

Let f be a nonconstant meromorphic function of hyper order strictly less than 1, and let c be a nonzero finite complex number such that f(z + c) ≢ f(z). We prove that if ∆_cf = f(z + c) - f(z) and f share 0, ∞ CM and 1 IM, then ∆_cf = f. Our result generalizes and greatly improves the related results.

• 대한수학회보
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• 제47권4호
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• pp.751-765
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• 2010

In this paper, we deal with a uniqueness theorem of two nonconstant meromorphic functions that share three values and one pair of polynomials. The results in this paper improve those given by G. G. Gundersen, G. Brosch and other authors.

• 대한수학회논문집
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• 제33권2호
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• pp.485-494
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• 2018

In this paper some newly developed results based on the growth properties of relative order (relative lower order), relative type (relative lower type) and relative weak type of entire and meromorphic functions on the basis of integer translation applied upon them are investigated.

• 대한수학회보
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• 제40권4호
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• pp.553-564
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• 2003

We give sufficient coefficient conditions for starlikeness of a class of complex-valued multivalent meromorphic harmonic and orientation preserving functions in outside of the unit disc. These coefficient conditions are also shown to be necessary if the coefficients of the analytic part of the harmonic functions are positive and the coefficients of the co-analytic part of the harmonic functions are negative. We then determine the extreme points, distortion bounds, convolution and convex combination conditions for these functions.