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1.
In this paper, comparing to (25) contractive type mappings defined by B. E. Rhoades we get a class of more general contractive type mappings. In virtue of this, we discuss two new fixed point theorems. And further, we derive two fixcd point existence theorems for (25) contractive type mappings.  相似文献   

2.
半模糊凸模糊映射   总被引:1,自引:1,他引:0  
In this paper, a new class of fuzzy mappings called semistrictly convex fuzzy mappings is introduced and we present some properties of this kind of fuzzy mappings. In particular, we prove that a local minimum of a semistrictly convex fuzzy mapping is also a global minimum. We also discuss the relations among convexity, strict convexity and semistrict convexity of fuzzy mapping, and give several sufficient conditions for convexity and semistrict convexity.  相似文献   

3.
In this paper, a class of biholomorphic mappings named quasi-convex mapping of order a in the unit ball of a complex Banach space is introduced. When the Banach space is confined to Cn, we obtain the relation between this class of mappings and the convex mappings. Furthermore, the growth and covering theorems of this class of mappings are given on the unit ball of a complex Banach space X. Finally, we get the second order terms coefficient estimations of the homogeneous expansion of quasi-convex mapping of order a defined on the polydisc in Cn and on the unit ball in a complex Banach space, respectively.  相似文献   

4.
In this article.a normalized biholomorphic mapping f defined on bounded starlike circular domain in C″is considered,where z=0 is a zero of order k 1 of f(z)(?) The sharp growth.covering theorems for almost starlike mappings of order a and starlile mappings of order wave established.Meanwhile,the construction of the above mappings on bounded starlike circular domain in C~n is also discussed,it provides the extremal mappings for the growth,covering theorems of the above mappings.  相似文献   

5.
In this paper,we introduce new concepts of α-type F-contractive mappings which are essentially weaker than the class of F-contractive mappings given in [21,22] and different from α-GF-contractions given in [8].Then,sufficient conditions for the existence and uniqueness of fixed point are established for these new types of contractive mappings,in the setting of complete metric space.Consequently,the obtained results encompass various generalizations of the Banach contraction principle.Moreover,some examples and an application to nonlinear fractional differential equation are given to illustrate the usability of the new theory.  相似文献   

6.
This paper is mainly about holomorphic mappings associated with conic regions which are closely connected with k-ST(α). We introduce new subclasses of starlike(spirallike) functions,namely, S_c~p(k, α)(S_c~p(k, α, β)), and discuss their coefficient estimates and the Fekete–Szeg?–Goluzin's problem. Then we generalize S_c~p(k, α, β) on the unit ball B~n in C~n, that is, k-conic spirallike mappings of type β and order α. We obtain the growth, covering and distortion theorems of the generalized mappings. Besides that, we construct k-conic spirallike mappings of type β and order α on B~n through S_c(k, α, β) by the generalized Roper-Suffridge extension operators.  相似文献   

7.
In this paper, we prove a local H¨older estimate of(K1, K2)-quasiconformal mappings between n-dimensional hypersurfaces of Rn+1under an assumption of bounded mean curvature of the original hypersurface M. With some new ingredients of the isoperimetric inequality and the co-area formula on manifolds, we extend Simon's work of quasiconformal mappings on surfaces of R3 to the setting of n-dimensional hypersurfaces of Rn+1.  相似文献   

8.
In this article, we mainly study the invariance of some biholomorphic mappings with special geometric characteristics under the extension operators. First we generalize the Roper-Suffridge extension operators on Bergman-Hartogs domains. Then, by the geometric characteristics of subclasses of biholomorphic mappings, we conclude that the modified Roper-Suff ridge operators preserve the properties of S_Ω~*(β,A, B), parabolic and spirallike mappings of type β and order p, strong and almost spirallike mappings of type 0 and orderα as well as almost starlike mappings of complex order λ on Ω_(p1,…,ps,q)~(B~n) under different conditions, respectively. The conclusions provide new approaches to construct these biholomorphic mappings in several complex variables.  相似文献   

9.
Nonlinear Galerkin methods are new schemes for integrating dissipative systems:In the present paper, we obtain the estimates to the rate of convergence of such methods for Kuramoto-Sivashinsky equations. In particular, by an illustrative example, we show that nonlinear Galerkin methods converge faster than the usual Galerkin method.  相似文献   

10.
Iterated function systems (IFS) were introduced by Hutchinson in 1981 as a natural generalization of the well-known Banach contraction principle.In 2010,D.R.Sahu and A.Chakraborty introduced K-Iterated Function System using Kannan mapping which would cover a larger range of mappings.In this paper,following Hutchinson,D.R.Sahu and A.Chakraborty,we present some new iterated function systems by using the so-called generalized contractive mappings,which will also cover a large range of mappings.Our purpose is to prove the existence and uniqueness of attractors for such class of iterated function systems by virtue of a Banach-like fixed point theorem concerning generalized contractive mappings.  相似文献   

11.
In this paper, we investigate whether consistent mappings can be used as homomorphism mappings between a covering based approximation space and its image with respect to twenty-two pairs of covering upper and lower approximation operators. We also consider the problem of constructing such mappings and minimizing them. In addition, we investigate the problem of reducing the data volume using consistent mappings as well as the maximum amount of their compressibility. We also apply our algorithms against several datasets.  相似文献   

12.
有界凸圆型域上的准凸映照   总被引:7,自引:1,他引:6  
刘太顺  刘浩 《数学学报》2001,44(2):287-292
本文研究星形映照的一类子族——有界凸圆型城上的准凸映照,并讨论了它与星形映照及凸映照的关系,建立其与凸映照同形的增长定理和掩盖定理.  相似文献   

13.
We continue to study the properties of covering mappings of metric spaces and present their applications to differential equations. To extend the applications of covering mappings, we introduce the notion of conditionally covering mapping. We prove that the solvability and the estimates for solutions of equations with conditionally covering mappings are preserved under small Lipschitz perturbations. These assertions are used in the solvability analysis of differential equations unsolved for the derivative.  相似文献   

14.
关于1-序列商映射   总被引:4,自引:1,他引:3  
谷建胜 《数学研究》2003,36(3):305-308,313
引进了1-序列商映射,证明了1-序列商映射象保持sm-第一可数空间.作为这一结果的一个应用,本文证明了几乎开,闭映射保持度量空间,g-度量空间,sm-度量空间.此外本文还证明了度量空间上的1-序列商,紧映射是1-序列覆盖映射.这些结果改进并推广了广义度量空间映射象的有关理论.  相似文献   

15.
In this paper, we investigate Clunie and Sheil-Small’s covering theorems for sense-preserving planar harmonic univalent mappings defined in the unit disk. Our results significantly improve the earlier known result. Also, we obtain a distortion theorem for fully starlike harmonic mappings in the unit disk.  相似文献   

16.
主要借助于紧覆盖映射、闭映射和商映射讨论了局部紧Lindel(o)f空间的像空间,推导出具有某些特定性质的k系空间的一些刻画,引入强k系的概念给出了局部紧Lindel(o)f空间和仿紧局部紧空间的一种新的等价刻画.  相似文献   

17.
仿紧局部cosmic空间的一些性质   总被引:2,自引:0,他引:2  
李进金 《数学研究》2000,33(3):340-344
给出仿紧局部cosmic空间的一些特征,建立了仿紧局部cosmic空间的几类序列覆盖L映象的特征,证明了闭L映射和商ss映射保持仿紧局部cosmic空间的性质,此外,还给出仿紧局部cosmic空间的一些映射性质。  相似文献   

18.
A coincidence point of a pair of mappings is an element, at which these mappings take on the same value. Coincidence points of mappings of partially ordered spaces were studied by A.V. Arutyunov, E.S. Zhukovskiy, and S.E. Zhukovskiy (see Topology and its Applications, 2015, V. 179, No. 1, p. 13–33); they proved, in particular, that an orderly covering mapping and a monotone one, both acting from a partially ordered space to a partially ordered one, possess a coincidence point. In this paper, we study the existence of a coincidence point of a pair of mappings that act from a partially ordered space to a set, where no binary relation is defined, and, consequently, it is impossible to define covering and monotonicity properties of mappings. In order to study the mentioned problem, we define the notion of a “quasi-coincidence” point. We understand it as an element, for which there exists another element, which does not exceed the initial one and is such that the value of the first mapping at it equals the value of the second mapping at the initial element. It turns out that the following condition is sufficient for the existence of a coincidence point: any chain of “quasi-coincidence” points is bounded and has a lower bound, which also is a “quasi-coincidence” point. We give an example of mappings that satisfy the above requirements and do not allow the application of results obtained for coincidence points of orderly covering and monotone mappings. In addition, we give an interpretation of the stability notion for coincidence points of mappings that act in partially ordered spaces with respect to their small perturbations and establish the corresponding stability conditions.  相似文献   

19.
In this paper, a class of biholomorphic mappings named quasi-convex mapping of order α in the unit ball of a complex Banach space is introduced. When the Banach space is confined to Cn, we obtain the relation between this class of mappings and the convex mappings.Furthermore, the growth and covering theorems of this class of mappings are given on the unit ball of a complex Banach space Ⅹ. Finally, we get the second order terms coefficient estimations of the homogeneous expansion of quasi-convex mapping of order α defined on the polydisc in Cn and on the unit ball in a complex Banach space, respectively.  相似文献   

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