• Kyungpook Mathematical Journal
• /
• 제53권3호
• /
• pp.371-383
• /
• 2013

In this paper, we investigate the uniqueness problem on entire functions sharing fixed points (ignoring multiplicities). Our main results improve and generalize some results due to Zhang [13], Qi-Yang [10] and Dou-Qi-Yang [1].

• Kyungpook Mathematical Journal
• /
• 제48권1호
• /
• pp.25-35
• /
• 2008

In this article, we deal with the uniqueness problems on meromorphic functions concerning differential polynomials that share fixed-points. Moreover we extend former results of W. C. Lin and H. X. Yi.

• 대한수학회논문집
• /
• 제15권2호
• /
• pp.275-284
• /
• 2000

The existence and convergence theorems for fixed points of mappings of asymptotically nonexpansive type are established in Banach spaces with a weakly continuous duality mapping but without uniform convexity.

• East Asian mathematical journal
• /
• 제25권1호
• /
• pp.1-10
• /
• 2009

In this paper, we prove some common fixed point theorems of compatible mappings under the generalized contractive type in metric spaces and also give some examples to illustrate our main theorems. This results extend the results of several authors.

• 충청수학회지
• /
• 제28권1호
• /
• pp.13-28
• /
• 2015

In this paper, we use two mappings satisfying certain expansive conditions to construct convergent sequences in complex valued metric spaces, and then we prove that the limits of the convergent sequences are the points of coincidence or common fixed points for the two mappings. The main theorems in this paper are the generalizations and improvements of the corresponding results in real metric spaces, cone metric spaces and topological vector space-valued cone metric spaces.

• 대한수학회보
• /
• 제23권2호
• /
• pp.155-160
• /
• 1986

Let X be a closed convex subset of a Banach space B and T:X.rarw.X a lipschitzian rotative map, i.e., such that ∥Tx-Ty∥.leq.k∥x-y∥ and ∥T$^{n}$ x-x∥.leq.a∥Tx-x∥ for some real k, a and an integer n>a. We denote by .PHI. (n, a, k, X) the family of all such maps. In [3], [4], K. Goebel and M. Koter obtained results concerning the existence of fixed points of T depending on k, a and n. In the present paper, the main results of [3], [4] are so strengthened that some information concerning the geometric estimations of fixed points are given.

• Kyungpook Mathematical Journal
• /
• 제58권4호
• /
• pp.689-695
• /
• 2018

In this paper, we give some results on the zeros and fixed points of the difference and the divided difference of transcendental meromorphic functions. This improves on results of Langley.

• 대한수학회보
• /
• 제34권2호
• /
• pp.247-257
• /
• 1997

It was the turning point in the "fixed point arena" when the notion of weak commutativity was introduced by Sessa [9] as a sharper tool to obtain common fixed points of mappings. As a result, all the results on fixed point theorems for commuting mappings were easily transformed in the setting of the new notion of weak commutativity of mappings. It gives a new impetus to the studying of common fixed points of mappings satisfying some contractive type conditions and a number of interesting results have been found by various authors. A bulk of results were produced and it was the centre of vigorous research activity in "Fixed Point Theory and its Application in various other Branches of Mathematical Sciences" in last two decades. A major break through was done by Jungck [3] when he proclaimed the new notion what he called "compatibility" of mapping and its usefulness for obtaining common fixed points of mappings was shown by him. There-after a flood of common fixed point theorems was produced by various researchers by using the improved notion of compatibility of mappings. of compatibility of mappings.

• 대한수학회보
• /
• 제48권5호
• /
• pp.1015-1021
• /
• 2011

A point of a Riemann surface X is said to be its fixed point if it is a fixed point of one of its nontrivial holomorphic automorphisms. We start this note by proving that the set Fix(X) of fixed points of Riemann surface X of genus g${\geq}$2 has at most 82(g-1) elements and this bound is attained just for X having a Hurwitz group of automorphisms, i.e., a group of order 84(g-1). The set of such points is invariant under the group of holomorphic automorphisms of X and we study the corresponding symmetric representation. We show that its algebraic type is an essential invariant of the topological type of the holomorphic action and we study its kernel, to find in particular some sufficient condition for its faithfulness.

• 산업경영시스템학회지
• /
• 제34권2호
• /
• pp.1-8
• /
• 2011

This paper proposes a variable sampling interval multivariate $T^2$ control chart with sampling at fixed times, where samples are taken at specified equally spaced fixed time points and additional samples are allowed between these fixed times when indicated by the preceding $T^2$ statistics. At fixed sampling points, the $T^2$ statistics are composed of all quality characteristics and a part of quality characteristics are selected to obtain $T^2$ statistics at additional sampling points. A Markov chain approach is used to evaluate the performance of the proposed chart. Numerical studies for the performance of the proposed chart show that the proposed chart reduces the observations obtained from a process and detects the assignable cause of a process with low correlated quality characteristics quickly.