• Honam Mathematical Journal
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• v.40 no.4
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• pp.733-748
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• 2018

In this paper, we investigate a new subclass $S^{{\varphi},{\lambda}}_{{\Sigma}_m}$ of ${\Sigma}_m$ consisting of analytic and m-fold symmetric bi-univalent functions satisfying subordination in the open unit disk U. We consider the Fekete-$Szeg{\ddot{o}}$ inequalities for this class. Also, we establish estimates for the coefficients for this subclass and several related classes are also considered and connections to earlier known results are made.

• Journal of applied mathematics & informatics
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• v.40 no.1_2
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• pp.259-266
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• 2022

The present investigation is concerned with certain subclasses of alpha-convex functions with fixed point and defined with subordination in the unit disc E = {z :| z |< 1}. The estimates of the first four coefficients for the functions in these classes are obtained. The results due to various authors follow as special cases.

• Korean Journal of Mathematics
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• v.31 no.3
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• pp.243-258
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• 2023

A normalized analytic function f defined on the unit disk 𝔻 is starlike of reciprocal order α, 0 ≤ α < 1, if Re(f(z)/(zf'(z))) > α for all z ∈ 𝔻. Such functions are starlike and therefore univalent in 𝔻. Using the well-known Miller-Mocanu differential subordination theory, sufficient conditions involving differential inclusions are obtained for a normalized analytic function to be starlike of reciprocal order α. Furthermore, a few conditions are derived for a function f to belong to a subclass of reciprocal starlike functions, satisfying |f(z)/(zf'(z)) - 1| < 1 - α.

• Honam Mathematical Journal
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• v.45 no.4
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• pp.689-700
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• 2023

In this note, we establish a new subfamily of spirallike functions by making use of a generalized q-integral operator. We examine characterization rule for functions which are member of this subclass. We further obtain coefficient estimate, subordination results and integral mean inequalities for functions in this class. The Fekete-Szegö inequalities are also derived.

• Communications of the Korean Mathematical Society
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• v.39 no.2
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• pp.407-420
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• 2024

In this paper, we investigate some geometric properties of starlikeness connected with the hyperbolic cosine functions defined in the open unit disk. In particular, for the class of such starlike hyperbolic cosine functions, we determine the lower bounds of partial sums, Briot-Bouquet differential subordination associated with Bernardi integral operator, and bounds on some third Hankel determinants containing initial coefficients.

• Bulletin of the Korean Mathematical Society
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• v.53 no.1
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• pp.215-225
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• 2016

We consider a sufficient condition for w(z), analytic in ${\mid}z{\mid}$ < 1, to be bounded in ${\mid}z{\mid}$ < 1, where $w(0)=w^{\prime}(0)=0$. We apply it to the meromorphic starlike functions. Also, a certain Briot-Bouquet differential subordination is considered. Moreover, we prove that if $p(z)+zp^{\prime}(z){\phi}(p(z)){\prec}h(z)$, then $p(z){\prec}h(z)$, where $h(z)=[(1+z)(1-z)]^{\alpha}$, under some additional assumptions on ${\phi}(z)$.

• Communications of the Korean Mathematical Society
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• v.33 no.2
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• pp.445-458
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• 2018

In this article we study the inclusion properties of the Bessel-Struve kernel functions in the Janowski class. In particular, we find the conditions for which the Bessel-Struve kernel functions maps the unit disk to right half plane. Some open problems with this aspect are also given. The third order differential subordination involving the Bessel-Struve kernel is also considered. The results are derived by defining suitable classes of admissible functions. One of the recurrence relation of the Bessel-Struve kernel play an important role to derive the main results.

• Kyungpook Mathematical Journal
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• v.55 no.4
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• pp.953-967
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• 2015

In this article, by making use of a linear multiplier fractional differential operator $D^{{\delta},m}_{\lambda}$, we introduce a new subclass of spiral-like functions. The main object is to provide some subordination results for functions in this class. We also find sufficient conditions for a function to be in the class and derive Fekete-$Szeg{\ddot{o}}$ inequalities.

• Language and Information
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• v.12 no.1
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• pp.1-26
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• 2008

This paper proposes a dynamic approach to anaphoric resolution in conjunction phrases, in terms of Discourse Representation Theory. Unlike Kamp, van Genabith, and Reyle (forthcomming)'s analysis, it proposes two different types of discourse representation structures for conjunction phrases; one for coordinate phrases such as and conjunction phrases and the other one for subordination conjunction phrases such as when subordination phrases. Following Chung (1992), Chung (2004), every element is processed in the order of occurrence and conjunction operators in a non-sentence-initial position cause the ongoing DR to split in two with the same index. DRS conditions and accessibility are accordingly modified so that DRs for conjunction clauses can be accessible from DRs for main clauses.

• Communications of the Korean Mathematical Society
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• v.32 no.4
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• pp.971-977
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• 2017

For $p{\in}{\mathbb{N}}^{\ast}$ let ${\Sigma}_{p,0}$ denote the class of meromorphic functions of the form $g(z) ={\frac{1}{z^p}}+a_0+a_1z+{\cdots}$, $z{\in}U$. In the present paper we introduce a new subclass of the class ${\Sigma}_{p,0}$, using the subordination and the operator $J^n_{p,{\lambda}}$. This class will be denoted by $B^n_{p,{\lambda}}({\alpha},h)$ and we study some inclusion properties of this subclass.