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71.
Shiang-Tai Liu 《European Journal of Operational Research》2011,212(3):606-608
Data envelopment analysis (DEA) is a useful tool of efficiency measurement for firms and organizations. Kao and Hwang (2008) take into account the series relationship of the two sub-processes in a two-stage production process, and the overall efficiency of the whole process is the product of the efficiencies of the two sub-processes. To find the largest efficiency of one sub-process while maintaining the maximum overall efficiency of the whole process, Kao and Hwang (2008) propose a solution procedure to accomplish this purpose. Nevertheless, one needs to know the overall efficiency of the whole process before calculating the sub-process efficiency. In this note, we propose a method that is able to find the sub-process and overall efficiencies simultaneously. 相似文献
72.
讨论了二次李超三系的唯一分解,得到了二次李超三系分解为非退化不可约阶化理想的分解定理. 相似文献
73.
对于完备格L上给定的|I|×|I|的矩阵R,若存在|I|×|I|的L上的矩阵S满足S⊙S=R,则称S为R的平方根,其中I表示指标集|I|的基数,⊙在本文中指的是sup-T合成算子并且T是无限∨分配的保序的算子。本文给出了完备格上基于sup-T合成算子的矩阵平方根存在的充要条件以及相应的理论上的算法求解所有的平方根。 相似文献
74.
Lajos Soukup 《Discrete Mathematics》2011,311(15):1585
The use of elementary submodels is a simple but powerful method to prove theorems, or to simplify proofs in infinite combinatorics. First we introduce all the necessary concepts of logic, then we prove classical theorems using elementary submodels. We also present a new proof of Nash-Williams’s theorem on cycle decomposition of graphs, and finally we improve a decomposition theorem of Laviolette concerning bond-faithful decompositions of graphs. 相似文献
75.
Given a set S and a positive integer k, a binary structure is a function . The set S is denoted by V(B) and the integer k is denoted by . With each subset X of V(B) associate the binary substructure B[X] of B induced by X defined by B[X](x,y)=B(x,y) for any x≠y∈X. A subset X of V(B) is a clan of B if for any x,y∈X and v∈V(B)?X, B(x,v)=B(y,v) and B(v,x)=B(v,y). A subset X of V(B) is a hyperclan of B if X is a clan of B satisfying: for every clan Y of B, if X∩Y≠0?, then X⊆Y or Y⊆X. With each binary structure B associate the family Π(B) of the maximal proper and nonempty hyperclans under inclusion of B. The decomposition tree of a binary structure B is constituted by the hyperclans X of B such that Π(B[X])≠0? and by the elements of Π(B[X]). Given binary structures B and C such that , the lexicographic product B⌊C⌋ of C by B is defined on V(B)×V(C) as follows. For any (x,y)≠(x′,y′)∈V(B)×V(C), B⌊C⌋((x,x′),(y,y′))=B(x,y) if x≠y and B⌊C⌋((x,x′),(y,y′))=C(x′,y′) if x=y. The decomposition tree of the lexicographic product B⌊C⌋ is described from the decomposition trees of B and C. 相似文献
76.
Zhuang Wajin 《东北数学》1995,(1)
PartialOrderingsintheCategoryofMatricesovertheQuaternionFieldZhuangWajin(庄瓦金)(DepartmentofMathematics,ZhangNormalCollege,Fuji... 相似文献
77.
Z. Mra 《国际流体数值方法杂志》1993,17(11):995-1002
A method of optimal design of Francis turbine tongue and wicket gate angle for given spiral casing is proposed. The potential flow in the doubly connected domain is decomposed into basic and circulation flows. The intensity of circulation is then calculated by the least-squares method minimizing the error function equal to the sum of squares of differences between given and calculated circumferential velocities in the outflow boundary nodes. It is shown that the error function has a sharp minimum, which qualifies the proposed method as well defined. For given numerical example, the variations in the outflow velocity angles are much smaller for optimal than for already used non-optimal design. A finite element method is used, with originally developed pre- and post-processor and frontal solver suited for personal computers. 相似文献
78.
We present a new methodology for solving large-scale employee tour scheduling problems. An integer programming model is proposed
where tours are decomposed into shifts and start times. This formulation can model complex shift and start time rules for
both continuous and discontinuous scheduling problems. A branch-and-price approach is devised to solve this model efficiently.
The methodology was tested on the largest tour scheduling problems found in the open literature. In comparison with an alternative
implicit model, our approach showed superior computational performance. 相似文献
79.
Yuichiro Fujiwara 《Discrete Mathematics》2007,307(13):1551-1558
A Steiner 2-design S(2,k,v) is said to be halvable if the block set can be partitioned into two isomorphic sets. This is equivalent to an edge-disjoint decomposition of a self-complementary graph G on v vertices into Kks. The obvious necessary condition of those orders v for which there exists a halvable S(2,k,v) is that v admits the existence of an S(2,k,v) with an even number of blocks. In this paper, we give an asymptotic solution for various block sizes. We prove that for any k?5 or any Mersenne prime k, there is a constant number v0 such that if v>v0 and v satisfies the above necessary condition, then there exists a halvable S(2,k,v). We also show that a halvable S(2,2n,v) exists for over a half of possible orders. Some recursive constructions generating infinitely many new halvable Steiner 2-designs are also presented. 相似文献
80.