共查询到20条相似文献,搜索用时 7 毫秒
1.
主要讨论了4一致l-超图的最小边数与最小上色数的关系,给出了上色数为3的4一致l-超图的最小边数的一个上界. 相似文献
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主要讨论了4一致L—超图的最小边数与最小上色数的关系,给出了上色数为3的4一致L—超图的最小边数的一个上界。 相似文献
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混合超图是含有两类超边的超图,一类称为C-超边,一类称为D-超边,它们的区别主要体现在染色要求上.混合超图的染色,要求每一C-超边至少有两个点染相同的颜色,而每一D-超边至少有两个点染不同的颜色.所用的最大颜色数称为对应混合超图的上色数,所用的最小颜色数称为对应混合超图的下色数.上、下色数与边数有密切关系.作者在文献[2]中证明了具有最小上色数的3一致C-超图边数的一个下界为‘n(n-2)/3’,其中n为对应混合超图的顶点数.该文证明当n=2k 1时,该下界是可以达到的. 相似文献
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郑国彪 《纯粹数学与应用数学》2011,27(3):308-312
混合超图的上,下色数与C-超边和D-超边数有着必然联系.一般地,增加C边会使下色数x(H)增加,增加D-超边会使上色数(x)(H)减小.本论文对D-完全一致混合超图进行研究,利用组合数学中分划思想及方法得到的D-完全一致混合超图不可着色的一个充要条件,对D-完全一致混合超图能否着色找到了可行的依据,进一步揭示C-超边数... 相似文献
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超图H=(V,E)顶点集为V,边集为E.S■V是H的顶点子集,如果H/S不含有圈,则称S是H的点反馈数,记τc(H)是H的最小点反馈数.本文证明了:(i)如果H是线性3-一致超图,边数为m,则τc(H)≤m/3;(ii)如果H是3-一致超图,边数为m,则τc(H)≤m/2并且等式成立当且仅当H任何一个连通分支是孤立顶点或者长度为2的圈.A■V是H的边子集,如果H\A不含有圈,则称A是H的边反馈数,记τc′(H)是H的最小边反馈数.本文证明了如果H是含有p个连通分支的3-一致超图,则τc’(H)≤2m-n+p. 相似文献
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1000多年前, 英国著名学者Alcuin曾提出过一个古老的渡河问题, 即狼、羊和卷心菜的渡河问题. 最近, Prisner和Csorba等考虑了一般``冲突图"上的渡河问题. 将这一问题推广到超图$H=(V,\mathcal{E})$\,上, 考虑一类情况更一般的运输计划问题. 现在监管者 欲运输超图中的所有点\,(代表``items")\,渡河, 这里$V$的点子 形成超边 当且仅当这些点代表的``items"在无人监管的情况下不能留在一起. 超图$H$的Alcuin数是指超图$H$具有可行运输方案\,(即把$V$的点代表的``items" 全部运到河对岸)\,时船的最小容量. 给出了 $r$-一致完全二部超图和它的伴随超图, 以及$r$-一致超图的Alcuin数, 同时证明了判断$r$-一致超图是否为小船图是NP 困难的. 相似文献
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图的限制边连通度是经典边连通度的推广,可用于精确度量网络的容错性.极大限制边连通图是使限制边连通度达到最优的一类图.首先将图的限制边连通度和最小边度的概念推广到r一致线性超图H,证明当H的最小度δ(H)≥r+1时,H的最小边度ξ(H)是它的限制边连通度λ′(H)的一个上界,并将满足ξ(H)=λ′(H)的H称为极大限制边连通超图,然后证明n个顶点的r一致线性超图H如果满足δ(H)≥(n-1)/(2(r-1))+(r-1),则它是极大限制边连通的,最后证明直径为2,围长至少为4的一致线性超图是极大限制边连通的.所得结论是图中相关结果的推广. 相似文献
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Jogi Henna 《Annals of the Institute of Statistical Mathematics》2005,57(4):655-664
An estimator of the number of components of a finite mixture ofk-dimensional distributions is given on the basis of a one-dimensional independent random sample obtained by a transformation
of ak-dimensional independent random sample. A consistency of the estimator is shown. Some simulation results are given in a case
of finite mixtures of two-dimensional normal distributions. 相似文献
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Piotr Je¸drzejewicz 《代数通讯》2013,41(4):1500-1508
Let A be a UFD of characteristic p > 0, let 𝒵 be a set of some eigenvectors of a derivation of A. We prove, under some additional assumptions, a necessary and sufficient condition for 𝒵 to be a p-basis of the minimal ring of constants containing 𝒵. The main preparatory result is the unique decomposition theorem with respect to a factor from a given subalgebra containing Ap. 相似文献
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N/Kbe a Galois extension of number fields with finite Galois group G.We describe a new approach for constructing invariants of the G-module structure of the K groups of the ring of integers of N in the Grothendieck group of finitely generated projective Z[G]modules. In various cases we can relate these classes, and their function field counterparts, to the root number class of Fröhlich and Cassou-Noguès. 相似文献
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有资格限制的指派问题的求解方法 总被引:3,自引:0,他引:3
在实际的指派工作中,常会遇到某个人有没有资格去承担某项工作的问题,因此,本建立了有资格限制的指派问题的数学模型。在此数学模型中,将效益矩阵转化为判定矩阵,由此给出了判定此种指派问题是否有解的方法;在有解的情况下,进一步将效益矩阵转化为求解矩阵,从而将有资格限制的指派问题化为传统的指派问题来求解。最后给出了一个数值例子来说明这样的处理方法是有效的。 相似文献
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We study the nilpotency of the sums of all coefficients of some sorts of products of polynomials over reversible, IFP, and NI rings, and introduce an SCN ring as a generalization. We characterize SCN rings in relation with related ring properties, and also provide several useful properties and ring extensions of SCN rings. 相似文献
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Rodney Y. Sharp 《Proceedings of the American Mathematical Society》2003,131(10):3009-3017
It is a well-known result of M. Brodmann that if is an ideal of a commutative Noetherian ring , then the set of associated primes of the -th power of is constant for all large . This paper is concerned with the following question: given a prime ideal of which is known to be in for all large integers , can one identify a term of the sequence beyond which will subsequently be an ever-present? This paper presents some results about convergence of sequences of sets of associated primes of graded components of finitely generated graded modules over a standard positively graded commutative Noetherian ring; those results are then applied to the above question.
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Let L be the Euclidean functional with p-th power-weighted edges. Examples include the sum of the p-th power-weighted lengths of the edges in minimal spanning trees, traveling salesman tours, and minimal matchings. Motivated
by the works of Steele, Redmond and Yukich (Ann. Appl. Probab. 4, 1057–1073, 1994, Stoch. Process. Appl. 61, 289–304, 1996) have shown that for n i.i.d. sample points {X
1,…,X
n
} from [0,1]
d
, L({X
1,…,X
n
})/n
(d−p)/d
converges a.s. to a finite constant. Here we bound the rate of convergence of EL({X
1,…,X
n
})/n
(d−p)/d
.
Y. Koo supported by the BK21 project of the Department of Mathematics, Sungkyunkwan University.
S. Lee supported by the BK21 project of the Department of Mathematics, Yonsei University. 相似文献
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Imme P. van den Berg 《Logic and Analysis》2008,1(2):153-185
One method to determine the asymptotics of particular solutions of a difference equation is by solving an associated asymptotic
functional equation. Here we study the behaviour of the solutions in an asymptotic neighbourhood of such individual solutions.
We identify several types of attraction and repulsion, which range from almost orthogonality to almost parallelness. Necessary
and sufficient conditions for these types of behaviour are given. 相似文献
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本文在LF拓扑空间中建立了L-fuzzy集网的弱收敛(R-收敛)概念,应用文[4]中的R-闭包,系统讨论了它们的性质,证明了等式RlimA_n=∧(∨A_m)_R和RlimA_n=A_n=∧(∨A_m)_R并且给出了L-fuzzy集网与其子网之间的关系。 相似文献