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1.
加性DEA模型与规模收益   总被引:1,自引:0,他引:1  
[1]给出了用C^2R模型或C^2GS^2模型来判断决策单元的规模收益情况的定理,指出它有时失效。对DEA有效(C^2GS^2)的决策单元,本用加性DEA模型来有效地判断其规模收益情况。  相似文献   

2.
利用锥拉伸与压缩不动点定理,给出了四阶微分方程奇异边值问题C^2[0,1]和C^2-[0,1]正解的存在性.  相似文献   

3.
Given two nuclear C^*-algebras A1 and A2 with states φ1 and φ2, we show that the monotone product C^*-algebra A1 △→ A2 is still nuclear. Furthermore, if both the states φ1 and φ2 are faithful, then the monotone product ,A1 △→ A2 is nuclear if and only if the C^*-algebras ,A1 and A2 both are nuclear.  相似文献   

4.
This paper presents a C^1-interpolation which preserves convexity to scattered convex data. The interpolant is local and explicitly described. The interpolating function si(x) is C^2 on each interval (xi, xi 1). Error will be O(h^2) when the function to he interpolated is C^3.  相似文献   

5.
权有附加约束的条件下的DEA有效性(C2R或C2GS2)   总被引:1,自引:0,他引:1  
有关判别决策单元在权有附加约束的条件下是否DEA有效(C^2或C^2GS^2),本文给出了一种基于权有附加约束条件下的加性模型的不同于文献[1]与[2]的约束与差别法。  相似文献   

6.
PrO-C*-代数的顺从性和核性   总被引:1,自引:0,他引:1  
研究了Pro—C^*-代数的顺从性和核性.主要证明了(1)顺从Pro—C^*代数的闭理想是顺从的;(2)核Pro—C^*代数类对归纳极限封闭;(3)交换σ-C^*-代数和核C^*-代数都是核,σ-C^*-代数并且核σ-C^*-代数类对于商运算、张量积运算和可数逆向极限封闭.进一步得到核,σ-C^*-代数的扩张保持核性的条件。  相似文献   

7.
一类四阶奇异边值问题的正解存在的充分必要条件   总被引:2,自引:0,他引:2  
利用上下解方法和极大值原理给出了一般边界条件下四阶微分方程的奇异迫值问题有C^2[0,1]和C^3[0,1]正解存在的充分必要条件.推广了韦忠礼(1999)的结果。  相似文献   

8.
张克敏 《数学研究》2000,33(3):324-328
图的圈基是图的一个重要结构,一个圈基的长度是该圈基中所有圈的长度之和,本讲座了简单图的圈基长度的最大值,得到了如下结果:设基圈数为k,顶点数为n的简单图的圈基长度最大值为C^*,i)若k≥4且n ≥k 2时,C^*-kn;Ⅱ)若k=2,3,则对任意n≥4,C^*=kn-1,Ⅲ)若n(n≥5)为奇数,则对k(k≥4)的所有可能值,C^*=kn。  相似文献   

9.
本文给出了C^*-代数的交换性的一系列等价刻划,特别,证明了C^*-代数A是交换的当且仅当存在正整数n≥2使得对所有a,b∈A^ ,下面的二项式公式成立:(a b)^n=∑k=0^nCn^ka^kb^n-k。  相似文献   

10.
本文把代数结构与分析体系结合起来,运用同调的方法,较系统地确定了A上C^*-模的部分理论,这里A为复数域C上的交换C^*-代数。即不仅定义了与C^*-模有关的某些新概念,而且还得到了有关C^*-模的若干结果。  相似文献   

11.
王漱石 《数学研究》1998,31(4):388-389,393
证明了Banach空间若有性质(La)则具有Kedec性质.  相似文献   

12.
This paper presents a hybrid method for identification of Pareto-optimal fuzzy classifiers (FCs). In contrast to many existing methods, the initial population for multiobjective evolutionary algorithms (MOEAs) is neither created randomly nor a priori knowledge is required. Instead, it is created by the proposed two-step initialization method. First, a decision tree (DT) created by C4.5 algorithm is transformed into an FC. Therefore, relevant variables are selected and initial partition of input space is performed. Then, the rest of the population is created by randomly replacing some parameters of the initial FC, such that, the initial population is widely spread. That improves the convergence of MOEAs into the correct Pareto front. The initial population is optimized by NSGA-II algorithm and a set of Pareto-optimal FCs representing the trade-off between accuracy and interpretability is obtained. The method does not require any a priori knowledge of the number of fuzzy sets, distribution of fuzzy sets or the number of relevant variables. They are all determined by it. Performance of the obtained FCs is validated by six benchmark data sets from the literature. The obtained results are compared to a recently published paper [H. Ishibuchi, Y. Nojima, Analysis of interpretability-accuracy tradeoff of fuzzy systems by multiobjective fuzzy genetics-based machine learning, International Journal of Approximate Reasoning 44 (1) (2007) 4–31] and the benefits of our method are clearly shown.  相似文献   

13.
得出了随机时间剩余寿命XY的随机比较性质和矩不等式.当Y是指数分布时求出了XY的故障率的界.  相似文献   

14.
Abstract

In 1956, Ehrenfeucht proved that a polynomial f 1(x 1) + · + f n (x n ) with complex coefficients in the variables x 1, …, x n is irreducible over the field of complex numbers provided the degrees of the polynomials f 1(x 1), …, f n (x n ) have greatest common divisor one. In 1964, Tverberg extended this result by showing that when n ≥ 3, then f 1(x 1) + · + f n (x n ) belonging to K[x 1, …, x n ] is irreducible over any field K of characteristic zero provided the degree of each f i is positive. Clearly a polynomial F = f 1(x 1) + · + f n (x n ) is reducible over a field K of characteristic p ≠ 0 if F can be written as F = (g 1(x 1)) p  + (g 2(x 2)) p  + · + (g n (x n )) p  + c[g 1(x 1) + g 2(x 2) + · + g n (x n )] where c is in K and each g i (x i ) is in K[x i ]. In 1966, Tverberg proved that the converse of the above simple fact holds in the particular case when n = 3 and K is an algebraically closed field of characteristic p > 0. In this article, we prove an extension of Tverberg's result by showing that this converse holds for any n ≥ 3.  相似文献   

15.
极大奇异积分算子的一个BLO估计   总被引:1,自引:0,他引:1  
胡国恩  张启慧 《数学进展》2007,36(1):101-107
本文研究以(Ω(x)/|z|n))为核的极大齐次奇异积分算子在空间BMO(R~n)上的性质,其中Ω是一个零阶齐次函数且在单位球面上均值为零.可以证明:若Ω满足某种最小尺度条件和某种L~1-Dini型正则性条件,则此极大奇异积分算子是由BMO(R~n)到BLO(R~n)的有界算子.  相似文献   

16.
In the face of acute global competition, supplier management is rapidly emerging as a crucial issue to any companies striving for business success and sustainable development. To optimize competitive advantages, a company should incorporate “suppliers” as an essential part of its core competencies. Supplier evaluation, the first step in supplier management, is a complex multi-criteria decision-making (MCDM) problem, and its complexity is further aggravated if the highly important interdependence among the selection criteria is taken into consideration. The objective of this paper is to suggest a comprehensive decision method for identifying top suppliers by considering the effects of interdependence among the selection criteria, as well as to achieve optimal allocation of orders among the selected suppliers.  相似文献   

17.
赵华  冯德成 《数学杂志》2002,22(2):185-190
本文引入了条件(wp),研究了其性质,建立了它与弱平坦性之间的联系,并利用其给出了某些幺半群的S-系范畴特征。  相似文献   

18.
在分销系统中,对库存补货策略进行科学管理与控制是一直是学者们研究的热点之一,学术界始终没有有效提高三个传统库存补货策略运作效率的有效方法.在两个传统补货策略(EB(echelon-based),TB(time-based))策略的基础上,从减少EB和TB策略的极端情况角度,提出了混合策略1(HBl,Hybrid Based Policy1)和混合策略2(HB2,Hybrid Based Policy2),并将HB1和HB2的优点结合起来形成双混合策略(RH,Re-Hybrid Policy).数值试验表明,HB1、HB2对EB、TB的总成本费用比率有不同程度的改善,同时RH能有效改善HB1、HB2的总成本费用比率.  相似文献   

19.
This paper addresses the problem of the fault detection for linear time-invariant systems over data networks with limited network Quality of Services (QoS). An integrated index ηkηk, which related with data dropout, network-induced delay and error sequence, is presented to described the non-ideal QoS, the probabilistic switching between different ηkηk is assumed to obey a homogeneous Markovian chain. Then by view of the augmented matrices approach, the fault detection error dynamic systems are transferred to Markov jumping systems (MJSs). With the developed model and using the bounded real lemma (BRL) for MJSs, an HH observer-based fault detection filter is established in terms of linear matrix inequalities (LMIs) to guarantee that the error between the residual and the weighted faults is made as small as possible. A simulation example is provided to show the effectiveness of the present methods.  相似文献   

20.
Supply chain design is becoming a core competency, and the enterprise resource planning (ERP) system is expected to be an integral component of supply chain management (SCM). Installing an ERP system is, however, expensive and risky. IT managers must decide how to use their limited resources and invest in the right product. Can an ERP system directly improve SCM competency? This study proposes a conceptual framework featuring the ERP benefits and SCM competencies, and examines the impacts of the former on the latter. The results confirm the operational, managerial, and strategic benefits of ERP for the SCM competencies, but not the IT infrastructure and organizational benefits as significant predictors of them. Moreover, more than 80% of respondents think it necessary to first adopt an ERP system as the backbone of company operations before deploying other enterprise systems (ES), such as the SCM system.  相似文献   

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