共查询到20条相似文献,搜索用时 109 毫秒
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何家莉 《纯粹数学与应用数学》2019,35(2):229-234
利用一般映射研究了覆盖近似空间的一些性质,并证明了一些结论.接着定义了覆盖空间的粗糙连续映射及粗糙同胚映射.最后在覆盖粗糙连续映射和覆盖粗糙同胚映射的条件下,研究了两个覆盖近似空间的有关性质,进而在某种程度上为覆盖近似空间的分类提供了理论依据. 相似文献
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本文研究了强α空间在有限到一的闭映射下的映射性质问题.利用闭映射的等价刻画构造g函数,获得了强α空间在有限到一的闭映射下保持的结果,改进了强α空间在有限到一的既开又闭映射下保持的结果.本文还研究了σ空间的半层对应刻画. 相似文献
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本文研究球空间中子流形的共形高斯映射,用Moebius不变量刻划了该映射 为调和映射的条件.作为特例,指出球空间的2维子流形的共形高斯映射是调和映射 当且仅当该子流形是Willmore子流形. 相似文献
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S.Koziel和Z.Michalewicz(1999年)提出了一个处理约束的映射,研究该映射与不同算法相结合后的不同的代数结构.从理论上证明了当其与遗传算法相结合时,该映射是同构映射,而在差分演化算法的变异操作下,该映射不是同态映射,更不是同构映射.进而表明,该映射更适宜于与遗传算法相结合,而并不太适宜于与差分演化算法(及其类似的算法)相结合。 相似文献
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《数学物理学报(A辑)》2017,(2)
各种双全纯映射的偏差估计一直是多复变函数论研究的热点之一.自强α型螺形映射的定义被提出以来,研究人员仅获得了增长与掩盖结果,但对其偏差结果却知之甚少.针对这一情况,利用强α型螺形映射的增长结果,首次获得了复Banach空间中开单位球B及欧式空间中单位多圆柱D~n单位方向上的强α型螺形映射的偏差估计.研究结果使人们对强α型螺形映射的性质有了新的认识. 相似文献
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拟共形映射能较好地保持角度,在形状编辑等几何处理领域有着广泛应用.但该类映射不易构造,特别是复杂区域之间的拟共形映射构造,是一个困难且重要的问题.本文研究了一类简单的拟共形映射,即双线性映射,讨论了其伸缩率的分布情况,证明了伸缩率的最大值一定在四边形区域的顶点上取得.相关结论为复杂区域之间拟共形映射的构造提供了良好的理论基础.数值实验验证了结论的正确性. 相似文献
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In this paper, we shall discuss the family of biharmonic mappings for which the maximum principle holds. As a consequence of our study, we present Schwarz Lemma for certain class of biharmonic mappings. Also we discuss the univalency of certain class of biharmonic mappings. 相似文献
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Shaoyuan Xu 《分析论及其应用》2007,23(3):274-282
E E. Browder and W. V. Petryshyn defined the topological degree for A- proper mappings and then W. V. Petryshyn studied a class of A-proper mappings, namely, P1-compact mappings and obtained a number of important fixed point theorems by virtue of the topological degree theory. In this paper, following W. V. Petryshyn, we continue to study P1-compact mappings and investigate the boundary condition, under which many new fixed point theorems of P1-compact mappings are obtained. On the other hand, this class of A-proper mappings with the boundedness property includes completely continuous operators and so, certain interesting new fixed point theorems for completely continuous operators are obtained immediately. As a result of it, our results generalize several famous theorems such as Leray-Schauder's theorem, Rothe's theorem, Altman's theorem, Petryshyn's theorem, etc. 相似文献
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In this note, we present a general automatic continuity theory for linear mappings between certain topological vector spaces. The theory applies, in particular, to local operators between spaces of functions and distributions, to algebraic homomorphisms between certain topological algebras, and to linear mappings intertwining generalized scalar operators. 相似文献
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The aim of this paper is to investigate some properties of planar harmonic and biharmonic mappings. First, we use the Schwarz
lemma and the improved estimates for the coefficients of planar harmonic mappings to generalize earlier results related to
Landau’s constants for harmonic and biharmonic mappings. Second, we obtain a new Landau’s Theorem for a certain class of biharmonic
mappings. At the end, we derive a relationship between the images of the linear connectivity of the unit disk
\mathbbD{\mathbb{D}} under the planar harmonic mappings f=h+[`(g)]{f=h+\overline{g}} and under their corresponding analytic counterparts F = h − g. 相似文献
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Peter Z. Daffer Hideaki Kaneko Wu Li 《Proceedings of the American Mathematical Society》1996,124(10):3159-3162
Simeon Reich (1974) proved that the fixed point theorem for single-valued mappings proved by Boyd and Wong can be generalized to multivalued mappings which map points into compact sets. He then asked (1983) whether his theorem can be extended to multivalued mappings whose range consists of bounded closed sets. In this note, we provide an affirmative answer for a certain subclass of Boyd-Wong contractive mappings.
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We examine a notion of generalized convex set-valued mapping, extending the notions of a convex relation and a convex process. Under general conditions, we establish duality results for composite set-valued mappings and for convex programming problems involving convex set-valued mappings. We also present applications to the study of economic dynamical systems, by obtaining the characteristics of optimal paths generated by convex processes, and to optimization problems of a certain class of positively homogeneous increasing functions. 相似文献
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Kamal N. Soltanov 《Nonlinear Analysis: Theory, Methods & Applications》2010,72(1):164-175
Here we consider perturbations of continuous mappings on Banach spaces, and investigate their images under various conditions. Consequently we study the solvability of some classes of equations and inclusions. For these we start by the investigation of local properties of the considered mapping and local comparisons of this mapping with certain smooth mappings. Moreover, we study different mixed problems. 相似文献
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In this paper we investigate the nearly small twist mappings with intersection property. With a certain non-degenerate condition, we proved that the most of invariant tori of the original small twist mappings will survive afer small perturtations. The persisted invariant tori are close to the unperturbed ones when the perturbation are small. The orbits reduced by those mappings are quasi-periodic in the invariant tori with the frequences closing to the original ones. 相似文献
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FixedPointTheoremsonaNon-convexSet¥ZhaoXiaoquan(赵晓全)andSunXuesi(孙学思)(DepartmentofMathematica,HarbinInstituteofElectricalTechn... 相似文献
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Bao She Wei 《数学学报(英文版)》2002,18(4):701-718
In this paper, we consider certain mappings, ${\mathcal {M}}In this paper, we consider certain mappings, ℳ , sufficiently close to an integrable one, which is weakly reversible with
respct to the mappings ? sufficiently close to an involution of tye (m, n), where m, n∈Z
+ are arbitrary. Under some weak non-degeneracy condition, we construct a uniform KAM iteration for providing the existence
of a Cantor family of m-tori invariant under the reversible mappings ℳ and the reversing mapping ?.
Received September 29, 1999, Accepted July 18, 2000 相似文献