共查询到15条相似文献,搜索用时 15 毫秒
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In this paper, we study the enhanced hypercube, an attractive variant of the hypercube and obtained by adding some complementary edges from a hypercube, and focus on cycles embedding on the enhanced hypercube with faulty vertices. Let Fu be the set of faulty vertices in the n-dimensional enhanced hypercube Qn,k (n ≥ 3, 1 ≤ k 〈≤n - 1). When IFvl = 2, we showed that Qn,k - Fv contains a fault-free cycle of every even length from 4 to 2n - 4 where n (n ≥ 3) and k have the same parity; and contains a fault-free cycle of every even length from 4 to 2n - 4, simultaneously, contains a cycle of every odd length from n-k + 2 to 2^n-3 where n (≥ 3) and k have the different parity. Furthermore, when |Fv| = fv ≤ n - 2, we prove that there exists the longest fault-free cycle, which is of even length 2^n - 2fv whether n (n ≥ 3) and k have the same parity or not; and there exists the longest fault-free cycle, which is of odd length 2^n - 2fv + 1 in Qn,k - Fv where n (≥ 3) and k have the different parity. 相似文献
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Let FF_v be the set of faulty nodes in an n-dimensional folded hypercube FQ_n with |FF_v| ≤ n-1 and all faulty vertices are not adjacent to the same vertex. In this paper, we show that if n ≥ 4, then every edge of FQn-FF_v lies on a fault-free cycle of every even length from 6 to 2~n-2|FF_v|. 相似文献
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Let G =(V, E) be a connected graph and m be a positive integer, the conditional edge connectivity λ_δ~m is the minimum cardinality of a set of edges,if it exists, whose deletion disconnects G and leaves each remaining component with minimum degree δ no less than m. This study shows that λ_δ~1(Q_(n,k)) = 2 n,λ_δ~2(Q_(n,k)) = 4 n-4(2 ≤ k ≤ n-1, n ≥ 3) for n-dimensional enhanced hypercube Q_(n,k). Meanwhile, another easy proof about λ_δ~2(Q_n) = 4 n-8, for n ≥ 3 is proposed. The results of enhanced hypercube include the cases of folded hypercube. 相似文献
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1引言设G=(V,E)为无向图.子集D (?)V(G)是无向图G的控制集,如果对于任意的y,∈V(G)-D,都存在x∈D,使xy∈E(G).G的控制集D是G的分裂控制集,如果G中由V(G)-D导出的子图G〈V(G)-D〉是不连通的.G的一个控制集D是G的一个强(弱)控制集,若dG(x)≥d_G(y)(d_G(x)≤d_G(y)),其中d_G(x)表示G中与点x关联的边数.对于有向图H=(V,A),子集D(?)V(H)称为H的控制集,如果对于任意的y∈ 相似文献
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Hong Jiaxing 《数学年刊B辑(英文版)》1999,20(2):123-136
The present paper is concerned with the existence of golbal smooth solutions for the homogeneous Dirichlet boundary value problem of the Darboux equation and the case degenerate on the boundary is contained. As some applications the smooth isometric embeddings of positively and nonnegatively curved disks into Rs are constructed. 相似文献
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We consider the class of polynomial differential equations x = -y+Pn(x,y), y = x + Qn(x, y), where Pn and Qn are homogeneous polynomials of degree n. Inside this class we identify a new subclass of systems having a center at the origin. We show that this subclass contains at least two subfamilies of isochro-nous centers. By using a method different from the classical ones, we study the limit cycles that bifurcate from the periodic orbits of such centers when we perturb them inside the class of all polynomial differential systems of the above form. In particular, we present a function whose simple zeros correspond to the limit cycles vvhich bifurcate from the periodic orbits of Hamiltonian systems. 相似文献
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一类三次系统极限环的存在唯一性 总被引:8,自引:0,他引:8
本文得到三次系统x=-y(1-ax)(1-ax) δx-lx3,y=x(1-ax)(1-bx)极限环的存在性、唯一性及不存在性的完整结果. 相似文献
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二维非线性动力系统的多极限环分叉的参数控制 总被引:3,自引:0,他引:3
本文研究了一类具有Z2-等变性质的5次扰动平面Hamilton向量场,利用动力系统的分叉理论和判定函数法,通过控制其参数,得到系统在两组不同的参数条件下分别存在20和23个极限环,以及它们之间相对位置的不同构型.这一结果对机械振动中相应的控制问题有理论指导意义。 相似文献
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一类四次系统极限环的个数与分布 总被引:1,自引:0,他引:1
本文研究一类四次系统的极限环,通过计算四次系统鞍点分界线之间的有向距离,计算一阶焦点量 及二阶焦点量,判别同宿轨内外的稳定性,利用分支理论与定性分析技巧发现这类系统有六个极限环, 并给出了它们的分布. 相似文献
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Cycle base theory of a graph has been well studied in abstract mathematical field such matroid theory as Whitney and Tutte did and found many applications in pratical uses such as electric circuit theory and structure analysis, etc. In this paper graph embedding theory is used to investigate cycle base structures of a 2-(edge)-connected graph on the sphere and the projective plane and it is shown that short cycles do generate the cycle spaces in the case of ““““small face-embeddings““““. As applications the authors find the exact formulae for the minimum lengthes of cycle bases of some types of graphs and present several known results. Infinite examples shows that the conditions in their main results are best possible and there are many 3-connected planar graphs whose minimum cycle bases can not be determined by the planar formulae but may be located by re-embedding them into the projective plane. 相似文献