期刊文献+
共找到2,479篇文章
< 1 2 124 >
每页显示 20 50 100
The Circular Chromatic Number of Some Special Graphs
1
作者 殷翔 陈旭瑾 宋增民 《Journal of Southeast University(English Edition)》 EI CAS 2001年第1期73-75,共3页
The circular chromatic number of a graph is a natural generalization of the chromatic number. Circular chromatic number contains more information about the structure of a graph than chromatic number does. In this pape... The circular chromatic number of a graph is a natural generalization of the chromatic number. Circular chromatic number contains more information about the structure of a graph than chromatic number does. In this paper we obtain the circular chromatic numbers of special graphs such as C t k and C t k-v, and give a simple proof of the circular chromatic number of H m,n . 展开更多
关键词 circular chromatic number graph C t k graph C t k-v graph H m n
下载PDF
Ramsey numbers r(K_(1, 4), G) for all three-partite graphs G of order six
2
作者 顾华 宋洪雪 刘向阳 《Journal of Southeast University(English Edition)》 EI CAS 2004年第3期378-380,共3页
In this paper, we use a combinatorial analysis method. In the complete graph K N with edges colored arbitrarily by red or blue, we consider the proposition of the subgraph of the red graph or blue graph induced by t... In this paper, we use a combinatorial analysis method. In the complete graph K N with edges colored arbitrarily by red or blue, we consider the proposition of the subgraph of the red graph or blue graph induced by the neighborhood of some vertex in V(K N). Inspired by the main results of Jayawardene and Rousseau (Ars Combinatoria, 2000, 163-173), we determine the Ramsey numbers of r(K 1, 4, G), where G is the three-partite graph of order six without isolate vertex. 展开更多
关键词 Ramsey number the graph of order six three-partite graph
下载PDF
Maximum Number of Edges of (rK_t)-Free Graphs
3
作者 孙良 杨刚 《Journal of Beijing Institute of Technology》 EI CAS 1997年第1期9-13,共5页
With positive integers r,t and n,where n≥rt and t≥2,the maximum number of edges of a simple graph of order n is estimated,which does not contain r disjoint copies of K_r for r=2 and 3.
关键词 extremal graph complete graph edge number
下载PDF
Circular L(j,k)-labeling numbers of trees and products of graphs 被引量:3
4
作者 吴琼 林文松 《Journal of Southeast University(English Edition)》 EI CAS 2010年第1期142-145,共4页
Let j, k and m be three positive integers, a circular m-L(j, k)-labeling of a graph G is a mapping f: V(G)→{0, 1, …, m-1}such that f(u)-f(v)m≥j if u and v are adjacent, and f(u)-f(v)m≥k if u and v are... Let j, k and m be three positive integers, a circular m-L(j, k)-labeling of a graph G is a mapping f: V(G)→{0, 1, …, m-1}such that f(u)-f(v)m≥j if u and v are adjacent, and f(u)-f(v)m≥k if u and v are at distance two,where a-bm=min{a-b,m-a-b}. The minimum m such that there exists a circular m-L(j, k)-labeling of G is called the circular L(j, k)-labeling number of G and is denoted by σj, k(G). For any two positive integers j and k with j≤k,the circular L(j, k)-labeling numbers of trees, the Cartesian product and the direct product of two complete graphs are determined. 展开更多
关键词 circular L(j k)-labeling number TREE Cartesian product of graphs direct product of graphs
下载PDF
The Number of Maximal Independent Sets in Quasi-Tree Graphs and Quasi-Forest Graphs
5
作者 Jenq-Jong Lin Min-Jen Jou 《Open Journal of Discrete Mathematics》 2017年第3期134-147,共14页
A maximal independent set is an independent set that is not a proper subset of any other independent set. A connected graph (respectively, graph) G with vertex set V(G) is called a quasi-tree graph (respectively, quas... A maximal independent set is an independent set that is not a proper subset of any other independent set. A connected graph (respectively, graph) G with vertex set V(G) is called a quasi-tree graph (respectively, quasi-forest graph), if there exists a vertex x &isin;V(G) such that G &minus;x?is a tree (respectively, forest). In this paper, we survey on the large numbers of maximal independent sets among all trees, forests, quasi-trees and quasi-forests. In addition, we further look into the problem of determining the third largest number of maximal independent sets among all quasi-trees and quasi-forests. Extremal graphs achieving these values are also given. 展开更多
关键词 MAXIMAL independent Set Quasi-Tree graph Quasi-Forest graph EXTREMAL graph
下载PDF
An Alternative Proof of the Largest Number of Maximal Independent Sets in Connected Graphs Having at Most Two Cycles
6
作者 Min-Jen Jou Jenq-Jong Lin 《Open Journal of Discrete Mathematics》 2016年第4期227-237,共11页
G. C. Ying, Y. Y. Meng, B. E. Sagan, and V. R. Vatter [1] found the maximum number of maximal independent sets in connected graphs which contain at most two cycles. In this paper, we give an alternative proof to deter... G. C. Ying, Y. Y. Meng, B. E. Sagan, and V. R. Vatter [1] found the maximum number of maximal independent sets in connected graphs which contain at most two cycles. In this paper, we give an alternative proof to determine the largest number of maximal independent sets among all connected graphs of order n ≥ 12, which contain at most two cycles. We also characterize the extremal graph achieving this maximum value. 展开更多
关键词 Maximal independent Set Connected graph Having at Most Two Cycles
下载PDF
CHROMATIC NUMBER OF SQUARE OF MAXIMAL OUTERPLANAR GRAPHS
7
作者 Luo Xiaofang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2007年第2期163-168,共6页
Let x(G^2) denote the chromatic number of the square of a maximal outerplanar graph G and Q denote a maximal outerplanar graph obtained by adding three chords y1 y3, y3y5, y5y1 to a 6-cycle y1y2…y6y1. In this paper... Let x(G^2) denote the chromatic number of the square of a maximal outerplanar graph G and Q denote a maximal outerplanar graph obtained by adding three chords y1 y3, y3y5, y5y1 to a 6-cycle y1y2…y6y1. In this paper, it is proved that △ + 1 ≤ x(G^2) ≤△ + 2, and x(G^2) = A + 2 if and only if G is Q, where A represents the maximum degree of G. 展开更多
关键词 chromatic number maximal outerplanar graph square of graph maximum degree
下载PDF
STABILITY NUMBER IN SUBCLASSES OF P_5^-FREE GRAPHS
8
作者 Zverovich I E Zverovich O I 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2004年第2期125-132,共8页
Two new hereditary classes of P 5-free graphs where the stability number can be found in polynomial time are proposed.They generalize several known results.
关键词 hereditary classes of graphs stability number forbidden induced subgraph
下载PDF
Game Chromatic Number of Some Regular Graphs
9
作者 Ramy Shaheen Ziad Kanaya Khaled Alshehada 《Open Journal of Discrete Mathematics》 2019年第4期159-164,共6页
Let G be a graph and k be a positive integer. We consider a game with two players Alice and Bob who alternate in coloring the vertices of G with a set of k colors. In every turn, one vertex will be chosen by one playe... Let G be a graph and k be a positive integer. We consider a game with two players Alice and Bob who alternate in coloring the vertices of G with a set of k colors. In every turn, one vertex will be chosen by one player. Alice’s goal is to color all vertices with the k colors, while Bob’s goal is to prevent her. The game chromatic number denoted by?&#967;g(G), is the smallest k such that Alice has a winning strategy with k colors. In this paper, we determine the game chromatic number?&#967;g of circulant graphs?Cn(1,2), , and generalized Petersen graphs GP(n,2), GP(n,3). 展开更多
关键词 GAME CHROMATIC number CIRCULANT graph Generalized Petersen graphS
下载PDF
Total Domination number of Generalized Petersen Graphs
10
作者 Jianxiang CAO Weiguo LIN Minyong SHI 《Intelligent Information Management》 2009年第1期14-17,共4页
Generalized Petersen graphs are an important class of commonly used interconnection networks and have been studied . The total domination number of generalized Petersen graphs P(m,2) is obtained in this paper.
关键词 generalized Petersen graphs TOTAL DOMINATION SET TOTAL DOMINATION number REGULAR graph domi- NATION SET DOMINATION number
下载PDF
The Generalization of Signed Domination Number of Two Classes of Graphs
11
作者 Xia Hong Guoyan Ao Feng Gao 《Open Journal of Discrete Mathematics》 2021年第4期114-132,共19页
Let <img src="Edit_092a0db1-eefa-4bff-81a0-751d038158ad.png" width="58" height="20" alt="" /> be a graph. A function <img src="Edit_b7158ed5-6825-41cd-b7f0-5ab5e16... Let <img src="Edit_092a0db1-eefa-4bff-81a0-751d038158ad.png" width="58" height="20" alt="" /> be a graph. A function <img src="Edit_b7158ed5-6825-41cd-b7f0-5ab5e16fc53d.png" width="79" height="20" alt="" /> is said to be a Signed Dominating Function (SDF) if <img src="Edit_c6e63805-bcaa-46a9-bc77-42750af8efd4.png" width="135" height="25" alt="" /> holds for all <img src="Edit_bba1b366-af70-46cd-aefe-fc68869da670.png" width="42" height="20" alt="" />. The signed domination number <img src="Edit_22e6d87a-e3be-4037-b4b6-c1de6a40abb0.png" width="284" height="25" alt="" />. In this paper, we determine the exact value of the Signed Domination Number of graphs <img src="Edit_36ef2747-da44-4f9b-a10a-340c61a3f28c.png" width="19" height="20" alt="" /> and <img src="Edit_26eb0f74-fcc2-49ad-8567-492cf3115b73.png" width="19" height="20" alt="" /> for <img src="Edit_856dbcc1-d215-4144-b50c-ac8a225d664f.png" width="32" height="20" alt="" />, which is generalized the known results, respectively, where <img src="Edit_4b7e4f8f-5d38-4fd0-ac4e-dd8ef243029f.png" width="19" height="20" alt="" /> and <img src="Edit_6557afba-e697-4397-994e-a9bda83e3219.png" width="19" height="20" alt="" /> are denotes the <em>k</em>-th power graphs of cycle <img src="Edit_27e6e80f-85d5-4208-b367-a757a0e55d0b.png" width="21" height="20" alt="" /> and path <img src="Edit_70ac5266-950b-4bfd-8d04-21711d3ffc33.png" width="18" height="20" alt="" />. 展开更多
关键词 Signed Domination Function Signed Domination numbers graphs Cn style="margin-left:-7px ">k graphs Pn style="margin-left:-7px ">k
下载PDF
The <i>H</i>-Decomposition Problem for Graphs
12
作者 Teresa Sousa 《Applied Mathematics》 2012年第11期1719-1722,共4页
The concept of H-decompositions of graphs was first introduced by Erd?s, Goodman and Pósa in 1966, who were motivated by the problem of representing graphs by set intersections. Given graphs G and H, an H-decompo... The concept of H-decompositions of graphs was first introduced by Erd?s, Goodman and Pósa in 1966, who were motivated by the problem of representing graphs by set intersections. Given graphs G and H, an H-decomposition of G is a partition of the edge set of G such that each part is either a single edge or forms a graph isomorphic to H. Let Ф(n,H) be the smallest number Ф, such that, any graph of order n admits an H-decomposition with at most Ф parts. The exact computation of Ф(n,H) for an arbitrary H is still an open problem. Recently, a few papers have been published about this problem. In this survey we will bring together all the results about H-decompositions. We will also introduce two new related problems, namely Weighted H-Decompositions of graphs and Monochromatic H-Decom- positions of graphs. 展开更多
关键词 graph Decompositions Weighted graph Decompositions Monochromatic graph Decompositions Turán graph Ramsey numbers
下载PDF
Circular Chromatic Numbers of Some Distance Graphs
13
作者 殷翔 吴建专 《Journal of Southeast University(English Edition)》 EI CAS 2001年第2期75-77,共3页
The circular chromatic number of a graph is an important parameter of a graph. The distance graph G(Z,D) , with a distance set D , is the infinite graph with vertex set Z={0,±1,±2,...} in which tw... The circular chromatic number of a graph is an important parameter of a graph. The distance graph G(Z,D) , with a distance set D , is the infinite graph with vertex set Z={0,±1,±2,...} in which two vertices x and y are adjacent iff y-x∈D . This paper determines the circular chromatic numbers of two classes of distance graphs G(Z,D m,k,k+1 ) and G(Z,D m,k,k+1,k+2 ). 展开更多
关键词 distance graph fractional chromatic number circular chromatic number
下载PDF
Some results on circular chromatic number of a graph
14
作者 吴建专 林文松 《Journal of Southeast University(English Edition)》 EI CAS 2008年第2期253-256,共4页
For two integers k and d with (k, d) = 1 and k≥2d, let G^dk be the graph with vertex set {0,1,…k - 1 } in which ij is an edge if and only if d≤| i -j I|≤k - d. The circular chromatic number χc(G) of a graph... For two integers k and d with (k, d) = 1 and k≥2d, let G^dk be the graph with vertex set {0,1,…k - 1 } in which ij is an edge if and only if d≤| i -j I|≤k - d. The circular chromatic number χc(G) of a graph G is the minimum of k/d for which G admits a homomorphism to G^dk. The relationship between χc( G- v) and χc (G)is investigated. In particular, the circular chromatic number of G^dk - v for any vertex v is determined. Some graphs withx χc(G - v) =χc(G) - 1 for any vertex v and with certain properties are presented. Some lower bounds for the circular chromatic number of a graph are studied, and a necessary and sufficient condition under which the circular chromatic number of a graph attains the lower bound χ- 1 + 1/α is proved, where χ is the chromatic number of G and a is its independence number. 展开更多
关键词 (k d)-coloring r-circular-coloring circular chromatic number Mycielski' s graph
下载PDF
NOTE ON CALCULATING WIENER NUMBERS OF MOLECULAR GRAPHS WITH SYMMETRY 被引量:2
15
作者 LiHuaien ZhangFuji 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1999年第2期191-196,共6页
The authors provided a simple method for calculating Wiener numbers of molecular graphs with symmetry in 1997.This paper intends to further improve on it and simplifies the calculation of the Wiener numbers of the mol... The authors provided a simple method for calculating Wiener numbers of molecular graphs with symmetry in 1997.This paper intends to further improve on it and simplifies the calculation of the Wiener numbers of the molecular graphs. 展开更多
关键词 1991 MR Subject Classification 05C12 KEYWORDS Wiener number point group molecular graph
下载PDF
EDGE-FACE CHROMATIC NUMBER OF 2-CONNECTED PLANE GRAPHS WITH HIGH MAXIMUM DEGREE 被引量:1
16
作者 张忠辅 王维凡 +2 位作者 李敬文 姚兵 卜月华 《Acta Mathematica Scientia》 SCIE CSCD 2006年第3期477-482,共6页
The edge-face chromatic number Xef (G) of a plane graph G is the least number of colors assigned to the edges and faces such that every adjacent or incident pair of them receives different colors. In this article, t... The edge-face chromatic number Xef (G) of a plane graph G is the least number of colors assigned to the edges and faces such that every adjacent or incident pair of them receives different colors. In this article, the authors prove that every 2-connected plane graph G with △(G)≥|G| - 2≥9 has Xef(G) = △(G). 展开更多
关键词 Plane graph edge-face chromatic number edge chromatic number maximum degree
下载PDF
Bondage Number of 1-Planar Graph 被引量:1
17
作者 Qiaoling Ma Sumei Zhang Jihui Wang 《Applied Mathematics》 2010年第2期101-103,共3页
The bondage number of a nonempty graph G is the cardinality of a smallest set of edges whose removal from G results in a graph a domination number greater than the domination number of G. In this paper, we prove that ... The bondage number of a nonempty graph G is the cardinality of a smallest set of edges whose removal from G results in a graph a domination number greater than the domination number of G. In this paper, we prove that for a 1-planar graph G. 展开更多
关键词 DOMINATION number Bondage number 1-Planar graph Combinatorial PROBLEM
下载PDF
NEIGHBORHOOD UNION OF INDEPENDENT SETS AND HAMILTONICITY OF CLAW-FREE GRAPHS
18
作者 XuXinping 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2005年第1期121-126,共6页
Let G be a graph,for any u∈V(G),let N(u) denote the neighborhood of u and d(u)=|N(u)| be the degree of u.For any UV(G),let N(U)=∪_~u∈U N(u), and d(U)=|N(U)|.A graph G is called claw-free if it has no induced subgra... Let G be a graph,for any u∈V(G),let N(u) denote the neighborhood of u and d(u)=|N(u)| be the degree of u.For any UV(G),let N(U)=∪_~u∈U N(u), and d(U)=|N(U)|.A graph G is called claw-free if it has no induced subgraph isomorphic to K_~1,3 .One of the fundamental results concerning cycles in claw-free graphs is due to Tian Feng,et al.: Let G be a 2-connected claw-free graph of order n,and d(u)+d(v)+d(w)≥n-2 for every independent vertex set {u,v,w} of G, then G is Hamiltonian. It is proved that,for any three positive integers s,t and w,such that if G is a (s+t+w-1)-connected claw-free graph of order n,and d(S)+d(T)+d(W)>n-(s+t+w) for every three disjoint independent vertex sets S,T,W with |S|=s,|T|=t,|W|=w,and S∪T∪W is also independent,then G is Hamiltonian.Other related results are obtained too. 展开更多
关键词 HAMILTONICITY claw-free graph independent set neighborhood union vertex insertion.
下载PDF
On Locating Numbers of Graphs
19
作者 Baogen Xu Chunhua Li Zhizhu Fan 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2018年第1期93-96,共4页
Let G =( V,E) be a connected graph and W = { w_1,w_2,…,w_k} be an ordered subset of V( G).For any vertex v ∈V,the locating code of v with respect to W is the k-vector CW( v) = { d( v,w_1),d( v,w_2),…,d( v,w_k) },W ... Let G =( V,E) be a connected graph and W = { w_1,w_2,…,w_k} be an ordered subset of V( G).For any vertex v ∈V,the locating code of v with respect to W is the k-vector CW( v) = { d( v,w_1),d( v,w_2),…,d( v,w_k) },W is said to be a locating set of G if distinct vertices have the distinct locating code,and the locating number of G is defined as: Loc( G) = min{ | W| : W is a locating set of G}.We study the locating set and locating number of a graph G,obtain some bounds for the locating numbers of graphs,and determine the exact value of Loc( G) for some special classes of graphs,such as cycles,wheels,complete t-partite graph and some Cartesian products of paths and cycles. In addition,we also prove that Loc( T) ≥Δ-1 holds for all trees T with maximum degree Δ,and shows a tree T with Loc( T) = Δ-1. 展开更多
关键词 graph locating code locating SET locating number CARTESIAN products
下载PDF
Bondage and Reinforcement Number of γ_f for Complete Multipartite Graph
20
作者 陈学刚 孙良 马德香 《Journal of Beijing Institute of Technology》 EI CAS 2003年第1期89-91,共3页
The bondage number of γ f, b f(G) , is defined to be the minimum cardinality of a set of edges whose removal from G results in a graph G′ satisfying γ f(G′)> γ f(G) . The reinforcement number of γ f, ... The bondage number of γ f, b f(G) , is defined to be the minimum cardinality of a set of edges whose removal from G results in a graph G′ satisfying γ f(G′)> γ f(G) . The reinforcement number of γ f, r f(G) , is defined to be the minimum cardinality of a set of edges which when added to G results in a graph G′ satisfying γ f(G′)< γ f(G) . G.S.Domke and R.C.Laskar initiated the study of them and gave exact values of b f(G) and r f(G) for some classes of graphs. Exact values of b f(G) and r f(G) for complete multipartite graphs are given and some results are extended. 展开更多
关键词 fractional domination number bondage number reinforcement number complete multipartite graph
下载PDF
上一页 1 2 124 下一页 到第
使用帮助 返回顶部