首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 46 毫秒
1.
王福  倪科社  郭志荣 《计算机工程》2010,36(11):247-249
基于组合设计中的循环差集,提出一种构造准循环低密度校验(Quasi-Cyclic LDPC)码的方法。所构造的正则Quasi-Cyclic LDPC码的校验矩阵中不存在长度为4的环,并且可以用简单线性移位寄存器实现编码。仿真结果表明,在和积迭代译码下,采用该方法构造的码具有较好的性能。  相似文献   

2.
网络拓扑图的搜索实现   总被引:1,自引:0,他引:1  
  相似文献   

3.
迪卡尔乘积图到Cayley图中的嵌入   总被引:1,自引:0,他引:1  
给出了一类图(迪卡尔乘积图)到另一类图(Cayley图的嵌入的一般方法,这些嵌入是这样实现的:首先把迪卡尔乘积图的每个“因子”图嵌入到主图中,然后取这些“因子”嵌入的积,进上步给出了一个定理,用来通过“因子”嵌入的性质来计算乘积嵌入的膨胀度。  相似文献   

4.
基于Web的网络拓扑图自动构造的研究与实现   总被引:4,自引:0,他引:4  
文中针对目前网络拓扑发展应用局限于网管工作站的不足,提出了一种基于Web的网络拓扑图的自动构造方法,使网络管理员能够通过浏览器了解网络的拓扑情况,并为其它基于Web的网管应用的进一步开发打下了基础。  相似文献   

5.
互连网络拓扑等价的图分析法   总被引:8,自引:1,他引:8  
提出了描述互连网络拓扑等价的图分析法。获得了全交叉网络与基准,逆基准,Omega,flip,S=F=2SW榕树,简化数据变换等多级互连网络拓扑等价的逻辑名结构。阐明了用光学全交叉网络模拟实现上述网络的互连函数的原理及其多处理机,电信交换等领域的潜在应用。  相似文献   

6.
多视点长景物图像指的是由一系列沿某一景物连续拍摄的图像拼接而成的长景物图像。提出了一种基于图割的由多视点构造长景物图像的新方法,该方法将由摄像机拍摄的原始图像投影到将要形成的长景物图像主平面上;再根据长景物图像形成的几个条件构建能量函数,将视点选择问题转变为能量函数最小化问题;通过Boykov等人提出的快速近似能量函数最小化的方法使其最小化,从而得到满足条件的长景物图像。实验结果显示,用该方法拼接而成的长景物图像在拼接处显得相当自然,真正做到了无缝光滑过渡。  相似文献   

7.
通过构造部分平衡不完全区组设计;得到一类低密度校验(LDPC)码;其最小环长(girth)至少为6;码率的选取具有很大的灵活性;而且可以具有准循环结构;进一步;也利用其构造了girth至少为8的准循环LDPC码。计算机仿真结果表明;在加性高斯白噪声信道中与随机码相比;我们构造的一些码具有稍好的译码性能。  相似文献   

8.
以SeeLink NMS网管系统的研发工作为基础,通过分析几种常见的网络拓扑图布局算法,针对园区级网络的特点,综合分而制之思想与环型布局思想,改进设计出一种适合园区级网络的拓扑图布局算法,并在SeeLink NMS中得以实现。  相似文献   

9.
互连网络拓扑等价的多样性与图分析法   总被引:2,自引:0,他引:2  
  相似文献   

10.
图数据广泛存在于现实世界中,可以自然地表示复合对象及其元素之间的复杂关联.对图数据的分类是一个非常重要且极具挑战的问题,在生物/化学信息学等领域有许多关键应用,如分子属性判断,新药发现等.但目前尚缺乏对于图分类研究的完整综述.首先给出图分类问题的定义和该领域的挑战;然后梳理分析了两类图分类方法—基于图相似度计算的图分类...  相似文献   

11.
LetG be a connected graph withn vertices andm edges. We develop an algorithm that finds the (unique) prime factors ofG with respect to the Cartesian product inO(m logn) time andO(m) space. This shows that factoringG is at most as costly as sorting its edges. The algorithm gains its efficiency and practicality from using only basic properties of product graphs and simple data structures.  相似文献   

12.
Cyclic bundle Hamiltonicity cbH(G) of a graph G is the minimal n for which there is an automorphism α of G such that the graph bundle C n α G is Hamiltonian. We define an invariant I that is related to the maximal vertex degree of spanning trees suitably involving the symmetries of G and prove cbH(G)≤I≤cbH(G)+1 for any non-trivial connected graph G.  相似文献   

13.
In this paper, we derive a simple formula for the number of spanning trees of the circulant graphs. Some special cases of the circulant graphs are also taken into account.  相似文献   

14.
A set S of vertices of a graph G is a dominating set for G if every vertex of G is adjacent to at least one vertex of S. The domination number γ(G), of G, is the minimum cardinality of a dominating set in G. Moreover, if the maximum degree of G is Δ, then for every positive integer k≤Δ, the set S is a k-dominating set in G if every vertex outside of S is adjacent to at least k vertices of S. The k-domination number of G, denoted by γ k (G), is the minimum cardinality of a k-dominating set in G. A map f: V→<texlscub>0, 1, 2</texlscub>is a Roman dominating function for G if for every vertex v with f(v)=0, there exists a vertex uN(v) such that f(u)=2. The weight of a Roman dominating function is f(V)=∑ uV f(u). The Roman domination number γR(G), of G, is the minimum weight of a Roman dominating function on G. In this paper, we obtain that for any two graphs G and H, the k-domination number of the Cartesian product of G and H is bounded below by γ(G k (H)/2. Also, we obtain that the domination number of Cartesian product of G and H is bounded below by γ(GR(H)/3.  相似文献   

15.
Let r≥ 4 be an even integer. Graph G is r-bipancyclic if it contains a cycle of every even length from r to 2n(G)2, where n(G) is the number of vertices in G. A graph G is r-pancyclic if it contains a cycle of every length from r to n(G), where r3. A graph is k-edge-fault Hamiltonian if, after deleting arbitrary k edges from the graph, the resulting graph remains Hamiltonian. The terms k-edge-fault r-bipancyclic and k-edge-fault r-pancyclic can be defined similarly. Given two graphs G and H, where n(G), n(H) 9, let k1, k25 be the minimum degrees of G and H, respectively. This study determined the edge-fault r-bipancyclic and edge-fault r-pancyclic of Cartesian product graph G×H with some conditions. These results were then used to evaluate the edge-fault pancyclicity (bipancyclicity) of NQmr,,m1 and GQmr,,m1.  相似文献   

16.
The (k−1)-fault diameter Dk(G) of a k-connected graph G is the maximum diameter of an induced subgraph by deleting at most k−1 vertices from G. This paper considers the fault diameter of the product graph G1G2 of two graphs G1 and G2 and proves that Dk1+k2(G1G2)?Dk1(G1)+Dk2(G2)+1 if G1 is k1-connected and G2 is k2-connected. This generalizes some known results such as Bani? and ?erovnik [I. Bani?, J. ?erovnik, Fault-diameter of Cartesian graph bundles, Inform. Process. Lett. 100 (2) (2006) 47-51].  相似文献   

17.
    
Complex networks have been a prominent topic of research for several years, spanning a wide range of fields from mathematics to computer science and also to social and biological sciences. The eigenvalues of the Seidel matrix, Seidel Signless Laplacian matrix, Seidel energy, Seidel Signless Laplacian energy, Maximum and Minimum energy, Degree Sum energy and Distance Degree energy of the Unitary Cayley graphs [UCG] have been calculated. Low-power devices must be able to transfer data across long distances with low delay and reliability. To overcome this drawback a small-world network depending on the unitary Cayley graph is proposed to decrease the delay and increase the reliability and is also used to create and analyze network communication. Small-world networks based on the Cayley graph have a basic construction and are highly adaptable. The simulation result shows that the small-world network based on unitary Cayley graphs has a shorter delay and is more reliable. Furthermore, the maximum delay is lowered by 40%.  相似文献   

18.
In this paper, we study the existence of cycles of all lengths in the recursive circulant graphs, and we show a necessary and sufficient condition for the graph being pancyclic and bipancyclic.  相似文献   

19.
Let γ(G) denote the domination number of a digraph G and let CmCn denote the Cartesian product of Cm and Cn, the directed cycles of length m,n?2. In this paper, we determine the exact values: γ(C2Cn)=n; γ(C3Cn)=n if , otherwise, γ(C3Cn)=n+1; if , otherwise, .  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号