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 共查询到18条相似文献,搜索用时 46 毫秒
1.
孙向荣  贺伟 《数学进展》2007,36(3):354-362
空间式locale范畴SLoc是locale范畴Loc的余反射满子范畴,但对locale乘积不封闭.本文引入弱空间式locale,证明弱空间式locale范畴WSloc为范畴Loc的余反射满子范畴,且对locale秉积封闭.还证明了一个locale A是空间式的当且仅当它的枝映射localeN(A)是弱空间式的;一个空问式locale的每一个子locale都是空间式的当且仅当它的每一个子locale是弱空间式的.最后,证明了弱空间式性在定向函子下保持不变.  相似文献   

2.
贺伟  张耀明 《数学进展》2000,29(5):439-443
本文定义了locale的内部算子与边界算子,详细讨论了这两个算子的性质,进一步得到了locale形式的Kuratowski定理。  相似文献   

3.
贺伟  张耀明 《数学进展》2000,19(4):357-361
本文定义了Locale的内部算子与边界算子,详细讨论了这两个算子的性质,进一步得到了Locale形式的Kuratowski定理。  相似文献   

4.
贺伟  罗懋康 《中国科学A辑》2006,36(7):757-763
1972年, Isbell利用locale中由正规覆盖构成的一致结构的完备化, 证明了仿紧完全正则locale范畴是locale范畴的满反射子范畴. 本文通过在locale的补零元理想格上做核映射的方法, 给出locale的仿紧完全正则反射的明确构造, 并证明locale的仿紧完全正则反射是locale的 Stone-Čech紧化的子locale.  相似文献   

5.
文[1]在条件(C1)、(C2)和(C3)之下,利用组合同伦内点法讨论了非凸非线性规划问题K—K—T点的存在性,本文对条件(C2)和(C3)进行了改进和处理。  相似文献   

6.
利用待定连续函数的方法求出所需要的同伦映射 ,利用图形求出所需要的同伦映射 .介绍一种同伦映射的构造方法并给出具体表达式 .  相似文献   

7.
Locale范畴中的零维性   总被引:1,自引:0,他引:1  
贺伟  罗懋康 《数学学报》1998,41(3):539-544
本文讨论locale的零维性质,主要结果有:(1)给出localeA的核映射(nucleus)构成的localeN(A)中上确界的点式刻划,并得到了N(A)的紧性与A的紧性之间的关系;(2)给出零维locale与coherentlocale之间的关系,以及零维locale的紧零维反射;(3)给出零维locale范畴在locale范畴中的刻划.  相似文献   

8.
关于同伦正则态射   总被引:10,自引:1,他引:10  
该文在点标拓扑空间的范畴中引进了同伦正则态射的概念,研究了它存在的条件,性质以及它与同伦单(满)态,同伦正则单(满)态和同伦等价之间的密切关系。  相似文献   

9.
Locale的正则紧反射   总被引:1,自引:0,他引:1  
贺伟 《数学学报》1999,42(3):441-444
locale的正则紧反射函子的构造的明确描述问题是由BanaschewskiB.和MulveyC.J.于1980年提出的,十多年来一直没有进展。本文通过在locale上引入一种二元关系,给出了locale的正则紧反射函子的构造性描述。  相似文献   

10.
连通Locale的基本性质   总被引:3,自引:0,他引:3  
樊磊  郑崇友 《数学进展》2001,30(3):247-251
本文给出连通Locale的一些基本性质,这些性质既有连通拓扑空间在Locale理论中的对应性质,同时也有连通Locale独有的,此外还研究了与连通Locale相关的对象和映射的性质。  相似文献   

11.
本文证明了,当S·Smale[1]的点估计判据a(z0,f)=||Df(z0)-1·f(z0)||sup||Df-1(z0)·时,求Banach空间解析映照f零点的连续同伦H(t,z)≡f(z)+(t-1)f(z0)=0有定义于[0,1]上的解z(t),且对t∈[0,1],Hz(t,z(t))-1存在,进而F(Z(1))=0,可以用连续同伦方法求得f的零点.  相似文献   

12.
in this note, we answer positively a question by Belegradek and Kapovitch about the relation between rational homotopy theory and a problem in Riemannian geometry which asks that total spaces of which vector bundles over compact non-negative curved manifolds admit (complete) metrics with non-negative curvature.  相似文献   

13.
We consider regular epimorphisms in the category Loc of locales. Closed surjections with subfit domain are regular epimorphisms. However, there exists a closed surjection which is the composite of two regular epimorphisms without being regular epic itself. This example answers both of the following questions in the negative: Y. Li"s question of whether weak quotient maps are necessarily regular epimorphisms, and P. Johnstone"s related question of whether regular epimorphisms compose. It follows that not all extremal epimorphisms in Loc are regular. The weak quotient maps of Y. Li and the equationally closed subframes of A. Pultr and A. Tozzi are shown to be dual notions. We also give a new characterization of regular epimorphisms in Loc.  相似文献   

14.
In this paper we present an efficient algorithm to test if two given paths are homotopic; that is, whether they wind around obstacles in the plane in the same way. For paths specified by n line segments with obstacles described by n points, several standard ways achieve quadratic running time. For simple paths, our algorithm runs in O(n log n) time, which we show is tight. For self-intersecting paths the problem is related to Hopcrofts problem; our algorithm runs in O(n 3/2log n) time.  相似文献   

15.
In this paper, the homotopy perturbation method is directly applied to derive approximate solutions of the fractional KdV equation. The results reveal that the proposed method is very effective and simple for solving approximate solutions of fractional differential equations.  相似文献   

16.
本文给出了求解多目标规划的一种连续同伦方法 .首先 ,运用光滑熵函数将多目标多约束的问题化为单目标单约束的问题 ,然后构造了求解单目标问题的同伦方法 ,并证明了其大范围收敛性 .  相似文献   

17.
In this paper, for solving the finite-dimensional variational inequality problem
where F is a mapping from X to Rn, X = is nonempty (not necessarily bounded) and is a convex Cr+1 mapping, a homotopy method is presented. Under various conditions, existence and convergence of a smooth homotopy path from almost any interior initial point in X to a solution of the variational inequality problem is proven. It leads to an implementable and globally convergent algorithm and gives a new and constructive proof of existence of solution.  相似文献   

18.
《Applied Mathematical Modelling》2014,38(5-6):1607-1611
In this paper, He’s homotopy perturbation method (HPM) is applied for solving linear programming (LP) problems. This paper shows that some recent findings about this topic cannot be applied for all cases. Furthermore, we provide the correct application of HPM for LP problems. The proposed method has a simple and graceful structure. Finally, a numerical example is displayed to illustrate the proposed method.  相似文献   

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