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1.
In this paper an existence theorem of positive radial solutions to a class of semilinear elliptic systems is proved by the Leray-Schauder degree theorem. Also, a nonexistence theorem is obtained. As an application of the main theorem, an example is given.  相似文献   

2.
S-粗集与它的分解-还原   总被引:49,自引:7,他引:49  
利用S-粗集(singular  相似文献   

3.
By using function one direction S-rough sets (function one direction singular rough sets), this article presents the concepts of F-law, F-rough law, and the relation metric of rough law; by using these concepts, this article puts forward the theorem of F-law relation metric, two orders theorem of F-rough law relation metric, the attribute theorem of F-rough law band, the extremum theorem of F-rough law relation metric, the discovery principle of F-rough law and the application of F-rough law.  相似文献   

4.
COMPATIBLE EXTENSIONS OF FUZZY RELATIONS   总被引:1,自引:0,他引:1  
In 1930 Szpilrajn proved that any strict partial order can be embedded in a strict linear order.This theorem was later refined by Dushnik and Miller(1941),Hansson(1968), Suzumura(1976),Donaldson and Weymark(1998), Bossert(1999). Particularly Suzumura introduced the important concept of compatible extension of a(crisp)relation.These extension theorems have an important role in welfare economics. In particularSzpilrajn theorem is the main tool for proving a known theorem of Richter that establishes theequivalence between rational and congruous consumers. In 1999 Duggan proved a general extensiontheorem that contains all these results. In this paper we introduce the notion of compatible extension of a fuzzy relation and we provean extension theorem for fuzzy relations. Our result generalizes to fuzzy set theory the main part ofDuggan's theorem. As applications we obtain fuzzy versions of the theorems of Szpilrajn, Hanssonand Suzumura. We also prove that an asymmetric and transitive fuzzy relation has a com  相似文献   

5.
利用单向S-粗集,给出单向S-粗决策规律生成方法;给出上决策规律,下决策规律,单向S-粗决策规律核,单向S-粗决策规律带,单向S-粗决策规律壳的概念;利用这些概念,提出下决策规律传递定理,上决策规律传递定理,F-分离的属性定理,粗决策规律挖掘定理,与粗决策规律挖掘准则。  相似文献   

6.
By employing function one-direction S-rough sets and rough law generation method based on function S-rough sets, ¯ f-decomposition law and ¯ F-decomposition rough law are proposed, and the measurement of rough law variation in the process of rough law ¯ F-decomposition is researched. The concepts of law energy and attribute ¯ f-interference degree are presented, which make the variation of rough law become measurable. ¯ f-decomposition law energy characteristic theorem, ¯ fdecomposition law energy inequality theorem, ¯ F-decomposition rough law energy characteristic theorem, and ¯ f-decomposition law energy mean value theorem are presented.  相似文献   

7.
By using function S-rough sets (function singular rough sets), this paper gives rough law generation and the theorem of rough law generation. Based on these results above, the paper proposes rough law separation, the theorem of rough law separation, the compound generation theorem of rough law bands, and the principle of rough law bands. In the end, an application of rough law separation in recognizing the risk law of profit is presented.  相似文献   

8.
外P-集合与F-信息伪装   总被引:7,自引:0,他引:7  
P-集合(packet sets)是一个集合对,它是由内P-集合(internal packet sets)与外P-集合(outer packet sets )共同构成。P-集合具有动态性,利用外P-集合,给出F-信息伪装与F-信息伪装生成概念;提出F-信息伪装度量定理与信息伪装被恢复〖CD*2〗还原定理;给出辨识准则与方法。利用这些结果,给出F-信息伪装被恢复还原的应用。P-集合是研究动态信息系统的一个新理论和新方法。  相似文献   

9.
独立决定和非二元性选择函数的Arrow不可能性定理   总被引:3,自引:1,他引:2  
研究Arrow不可能性定理的弱化问题,将独立不相关条件(IIA)弱化为独立相关决定条件,证明在非二元性选择函数环境下对IIA弱化后Arrow不可能性定理仍然成立,并将它推广到选择函数不具有连通性的群格序决策问题。所得结论表明导致IIA弱化后,不可能性定理仍然成立的根本原因不是选择函数的连通性。  相似文献   

10.
This paper studies existence and uniqueness for random impulsive differential equations. The authors first generalize a random fixed point theorem of Schaefer’s type. Then the authors shall rely on the generalized Schaefer’s type random fixed point theorem to discuss the existence of the system. In addition, the authors study the existence and uniqueness of random impulsive differential equations by applying random Banach fixed point theorem and obtain some less conservative results. Finally, an example is given to illustrate the effectiveness of the results.  相似文献   

11.
无向马尔科夫毯结构是属性和类变量之间的最重要依赖结构之一,建立无向马尔科夫毯分类器的核心是无向马尔科夫毯结构学习。针对现有无向马尔科夫毯结构学习方法具有低效率和可靠性,以及不具实用性等问题,基于贝叶斯网络理论、马尔科夫网络理论和依赖分析方法进行具有多项式复杂度的无向马尔科夫毯结构和分类器学习,来避免这些问题。并建立最优性定理、可转换定理、可靠性定理和局部化定理为其提供理论依据。同时,对小例子集情况,给出了近似学习方法,并将无向马尔科夫毯分类器扩展为联合分类器,以有效地进行小例子集分类。  相似文献   

12.
本文从抽样定理和量化定理出发,导出了在信号处理系统中选A/D变换器的准则,该准则在工程上用处很大。  相似文献   

13.
Function one direction S-rough sets have dynamic characteristics and law characteristics. By using the function one direction S-rough sets, this article presents the concepts of the f-hiding law, F-hiding law, f-hiding law dependence and F-hiding law dependence. Based on the concepts above, this article proposes the hiding-dependence theorem of f-hiding laws, the hiding-dependence theorem of F-hiding laws, the hiding-dependence separation theorem, the hiding dependencs-discovery principle of unknown laws. Finally, the application of the hiding dependence of hiding laws in the discovery of system laws is given.  相似文献   

14.
In this paper we examine controllability problems of evolution inclusions with nonlocal conditions. Using Kakutani‘s fixed point theorem and Schauder‘s fixed point the-orem, we establish sufficient conditions for the controllability under convex and nonconvex orientor fields respectively.  相似文献   

15.
S-rough sets and knowledge separation   总被引:79,自引:12,他引:79  
1.INTRODUCTION GivensetX U,Risanequivalencerelationfamily ofU;[x]R;isanR equivalenceclass,andwehave Z.Pawlakroughsets(R-(X),R-(X))[10].Inset Uthereareriskelementswhichexistinriskestima tionsystem,earlywarninganalysissystem,etc.We can’tascertaintheirincursionorintrusiontosetX Uinprevious;theseelementshavethefollowingtwo features:u∈U,u∈-X f(u)=x∈X;x∈X f(x)=u∈-X.Inotherwords,duetotheeffectof f∈F,elementuwhichisnotinXturnsintof(u)=x,f(u)goesintoX;elementxwhichisinX,turnsinto f…  相似文献   

16.
均值-CVaR模型下的两基金分离定理   总被引:4,自引:0,他引:4  
两基金分离定理对资本资产定价模型的研究有重要意义.经典的理论以方差为风险度量方法,而CVaR是近年来提出的一种新的风险度量方法.本文基于CVaR风险度量方法,研究了正态情形下风险资产组合的均值-CVaR模型,得到了此模型下的两基金分离定理及其有关性质,并与均值-方差模型进行了比较.最后通过实例分析表明均值-CVaR模型下的两基金分离定理更能满足投资者不同的风险忍受水平.  相似文献   

17.
STABILITYOFSTEADY-STATESOLUTIONSOFTHECOMPETITIONMODELINTHECHEMOSTAT¥WUJianhua(Xi'anInstituteofHighway,Xi,an710064,China)LIYan...  相似文献   

18.
An optimal control棗the minimum energy control is proposed and discusses in this paper. The existence and uniqueness of the optimal control are shown, and an approximation theorem is proved in terms of semigroup methods of operators and geometric method. Finally, as an application of main theorem obtained, an example of the nuclear reactor is introduced.  相似文献   

19.
OPTIMALITY CONDITIONS IN NONSMOOTH MULTIOBJECTIVE PROGRAMMING   总被引:1,自引:0,他引:1  
OPTIMALITYCONDITIONSINNONSMOOTHMULTIOBJECTIVEPROGRAMMING¥WANGLiancheng;DONGJiali;LIUQinghuai(DepertmentofMathematics,JilinUni...  相似文献   

20.
A theorem of transformation between two geometries is proved on the basis of Wu's method of mechanical theorem proving.By using this theoremfor Cayley-Klein geometries of dimension two,we prove that the nine Cayley-Klein geometries can be divided into three groups within which the geometries aremutually equivalent in the sense that certain geometry statements are correct inone geometry if and only if they are correct in the other geometries of the samegroup.This means that for each group we only need to choose a model geometryto study and the theorems of other geometries in the same group can be obtainedfrom the model geometry automatically.The three model geometries chosen forthe nine Cayley-Klein geometries are:Euclidean geometry,Riemann geometry,andGalilean geometry.  相似文献   

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