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11.
The concept of balance vertices was first investigated by Reid (1999). For the main result “the balance vertices of a tree consist of a single vertex or two adjacent vertices”, Shan and Kang (2004) and Reid and DePalma (2005) improved the length and technique of the proof. In this paper we further discuss the balance vertices on trees in a generalization context. We do not only provide a simple efficient proof for the relevant result but also develop a linear time algorithm to find the set of balance vertices on the underlying tree. 相似文献
12.
Given two rooted, labeled trees P and T the tree path subsequence problem is to determine which paths in P are subsequences of which paths in T. Here a path begins at the root and ends at a leaf. In this paper we propose this problem as a useful query primitive for XML data, and provide new algorithms improving the previously best known time and space bounds. 相似文献
13.
14.
Endre?Bj?rndal Maurice?KosterEmail author Stef?Tijs 《Mathematical Methods of Operations Research》2004,59(2):249-270
In this paper we consider standard fixed tree games, for which each vertex unequal to the root is inhabited by exactly one player. We present two weighted allocation rules, the weighted down-home allocation and the weighted neighbour-home allocation, both inspired by the painting story in Maschler et al. (1995) . We show, in a constructive way, that the core equals both the set of weighted down-home allocations and the set of weighted neighbour allocations. Since every weighted down-home allocation specifies a weighted Shapley value (Kalai and Samet (1988)) in a natural way, and vice versa, our results provide an alternative proof of the fact that the core of a standard fixed tree game equals the set of weighted Shapley values. The class of weighted neighbour allocations is a generalization of the nucleolus, in the sense that the latter is in this class as the special member where players have all equal weights. 相似文献
15.
C. M. Da Fonseca 《Annali di Matematica Pura ed Applicata》2008,187(2):251-261
A different approach is given to recent results due mainly to R. C. Johnson and A. Leal Duarte on the multiplicities of eigenvalues
of a Hermitian matrix whose graph is a tree. The techniques developed are based on some results of matching polynomials and
used a work by O. L. Heilmann and E. H. Lieb on an apparently unrelated topic.
相似文献
16.
Effective Relaxations and Partitioning Schemes for Solving Water Distribution Network Design Problems to Global Optimality 总被引:2,自引:0,他引:2
Hanif D. Sherali Shivaram Subramanian G.V. Loganathan 《Journal of Global Optimization》2001,19(1):1-26
In this paper, we address the development of a global optimization procedure for the problem of designing a water distribution network, including the case of expanding an already existing system, that satisfies specified flow demands at stated pressure head requirements. The proposed approach significantly improves upon a previous method of Sherali et al. (1998) by way of adopting tighter polyhedral relaxations, and more effective partitioning strategies in concert with a maximal spanning tree-based branching variable selection procedure. Computational experience on three standard test problems from the literature is provided to evaluate the proposed procedure. For all these problems, proven global optimal solutions within a tolerance of 10–4% and/or within 1$ of optimality are obtained. In particular, the two larger instances of the Hanoi and the New York test networks are solved to global optimality for the very first time in the literature. A new real network design test problem based on the Town of Blacksburg Water Distribution System is also offered to be included in the available library of test cases, and related computational results are presented. 相似文献
17.
It is proved that every subspace of James Tree space (JT) with non-separable dual contains an isomorph of James Tree complemented in JT. This yields that every complemented subspace of JT with non-separable dual is isomorphic to JT. A new JT like space denoted as TF is defined. It is shown that every subspace of James Function space (JF) with non-separable dual contains an isomorph of TF. The later yields that every subspace of JF with non-separable dual contains isomorphs of c0 and ?p for 2?p<∞. The analogues of the above results for bounded linear operators are also proved. 相似文献
18.
1 引言可转换债券以其独特的风险受益特性逐渐为投、融资者所接受并得到了广泛的欢迎.如今,无论在广度还是深度上,全球范围的可转债市场都已经发生了质的变化,并且日趋成熟和繁荣.中国的可转债市场在经历了十余年的沉寂之后,近两年也正进入一个高速发 相似文献
19.
树上秘密共享体制的信息率 总被引:1,自引:0,他引:1
研究以树G为通道结构的秘密共享体制的最优信息率ρ(G)。得到了ρ(G)=2/3的要条件。证明了ρ(G)不会介于实数区间(3/5,2/3)中,给出了以树G的阶数表示的ρ(G)的下界,求出两类具有某种结构的树的最优信息率。 相似文献
20.
对新疆托木尔峰地区松树年轮样品的ESR研究表明,其自由基浓度N_g是树木生长速率的指示,它与季节有关。春材的N_g值普遍高于秋材,与气温、降雨量有关,但不是一一对应的关系。年轮的N_g明显地受太阳黑子活动周的影响,随着太阳周而变化,只是峰谷和峰值年要前移或后推1—2年。 相似文献