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Asymptotic upper bounds for wheel:complete graph Ramsey numbers
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作者 宋洪雪 《Journal of Southeast University(English Edition)》 EI CAS 2004年第1期126-129,共4页
It is shown that r(W_m, K_n)≤(1+o(1))C_1n log n 2m-2m-2 for fixed even m≥4 and n→∞, and r(W_m, K_n)≤(1+o(1))C_2n 2mm+1 log n m+1m-1 for fixed odd m≥5 and n→∞, wher... It is shown that r(W_m, K_n)≤(1+o(1))C_1n log n 2m-2m-2 for fixed even m≥4 and n→∞, and r(W_m, K_n)≤(1+o(1))C_2n 2mm+1 log n m+1m-1 for fixed odd m≥5 and n→∞, where C_1=C_1(m)>0 and C_2=C_2(m)>0, in particular, C_2=12 if m=5 . It is obtained by the analytic method and using the function f_m(x)=∫ 1 _ 0 (1-t) 1m dtm+(x-m)t , x≥0 , m≥1 on the base of the asymptotic upper bounds for r(C_m, K_n) which were given by Caro, et al. Also, cn log n 52 ≤r(K_4, K_n)≤(1+o(1)) n 3 ( log n) 2 (as n→∞ ). Moreover, we give r(K_k+C_m, K_n)≤(1+o(1))C_5(m)n log n k+mm-2 for fixed even m≥4 and r(K_k+C_m, K_n)≤(1+o(1))C_6(m)n 2+(k+1)(m-1)2+k(m-1) log n k+2m-1 for fixed odd m≥3 (as n→∞ ). 展开更多
关键词 Ramsey numbers WHEELS independent number complete graphs
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Quantum search of many vertices on the joined complete graph
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作者 Tingting Ji Naiqiao Pan +1 位作者 Tian Chen Xiangdong Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第7期182-193,共12页
The quantum search on the graph is a very important topic.In this work,we develop a theoretic method on searching of single vertex on the graph[Phys.Rev.Lett.114110503(2015)],and systematically study the search of man... The quantum search on the graph is a very important topic.In this work,we develop a theoretic method on searching of single vertex on the graph[Phys.Rev.Lett.114110503(2015)],and systematically study the search of many vertices on one low-connectivity graph,the joined complete graph.Our results reveal that,with the optimal jumping rate obtained from the theoretical method,we can find such target vertices at the time O(√N),where N is the number of total vertices.Therefore,the search of many vertices on the joined complete graph possessing quantum advantage has been achieved. 展开更多
关键词 quantum search the joined complete graph quantum walk many vertices
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A Decomposition of a Complete Graph with a Hole
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作者 Roxanne Back Alejandra Brewer Castano +1 位作者 Rachel Galindo Jessica Finocchiaro 《Open Journal of Discrete Mathematics》 2021年第1期1-12,共12页
<div style="text-align:justify;"> <span style="font-family:Verdana;">In the field of design theory, the most well-known design is a Steiner Triple System. In general, a G-design on H is... <div style="text-align:justify;"> <span style="font-family:Verdana;">In the field of design theory, the most well-known design is a Steiner Triple System. In general, a G-design on H is an edge-disjoint decomposition of H into isomorphic copies of G. In a Steiner Triple system, a complete graph is decomposed into triangles. In this paper we let H be a complete graph with a hole and G be a complete graph on four vertices minus one edge, also referred to as a <img alt="" src="Edit_e69ee166-4bbc-48f5-8ba1-b446e7d3738c.png" /> . A complete graph with a hole, <img alt="" src="Edit_558c249b-55e8-4f3b-a043-e36d001c4250.png" />, consists of a complete graph on d vertices, <img alt="" src="Edit_cb1772f7-837c-4aea-b4a6-cb38565f5a8b.png" />, and a set of independent vertices of size v, V, where each vertex in V is adjacent to each vertex in <img alt="" src="Edit_cb1772f7-837c-4aea-b4a6-cb38565f5a8b.png" />. When d is even, we give two constructions for the decomposition of a complete graph with a hole into copies of <img alt="" src="Edit_e69ee166-4bbc-48f5-8ba1-b446e7d3738c.png" /> : the Alpha-Delta Construction, and the Alpha-Beta-Delta Construction. By restricting d and v so that <img alt="" src="Edit_6bb9e3b4-1769-4b28-bf89-bc97c47c637e.png" /><span style="white-space:nowrap;"> , we are able to resolve both of these cases for a subset of <img alt="" src="Edit_558c249b-55e8-4f3b-a043-e36d001c4250.png" />using difference methods and 1-factors. 展开更多
关键词 graph Decomposition Combinatorial Design complete graph with a Hole
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Edge-Transitive Cyclic Covers of Complete Graphs with Prime Power Order
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作者 Zhaohong Huang Yin Liu 《Journal of Applied Mathematics and Physics》 2022年第2期289-300,共12页
Characterizing regular covers of symmetric graphs is one of the fundamental topics in the field of algebraic graph theory, and is often a key step for approaching general symmetric graphs. Complete graphs, which are t... Characterizing regular covers of symmetric graphs is one of the fundamental topics in the field of algebraic graph theory, and is often a key step for approaching general symmetric graphs. Complete graphs, which are typical symmetric graphs, naturally appear in the study of many symmetric graphs as normal quotient graphs. In this paper, a characterization of edge-transitive cyclic covers of complete graphs with prime power order is given by using the techniques of finite group theory and the related properties of coset graphs. Certain previous results are generalized and some new families of examples are founded. 展开更多
关键词 COVER complete graph Normal Quotient graph AUTOMORPHISM
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COMPLETE MULTIPARTITE DECOMPOSITIONS OF COMPLETE GRAPHS AND COMPLETE n-PARTITE GRAPHS
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作者 Huang QingxueDept. of Math., Zhejiang Univ., Hangzhou 310027, China. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2003年第3期352-360,共9页
In this paper,a new concept of an optimal complete multipartite decomposition of type 1 (type 2) of a complete n-partite graph Q n is proposed and another new concept of a normal complete multipartite decomposition o... In this paper,a new concept of an optimal complete multipartite decomposition of type 1 (type 2) of a complete n-partite graph Q n is proposed and another new concept of a normal complete multipartite decomposition of K n is introduced.It is showed that an optimal complete multipartite decomposition of type 1 of K n is a normal complete multipartite decomposition.As for any complete multipartite decomposition of K n,there is a derived complete multipartite decomposition for Q n.It is also showed that any optimal complete multipartite decomposition of type 1 of Q n is a derived decomposition of an optimal complete multipartite decomposition of type 1 of K n.Besides,some structural properties of an optimal complete multipartite decomposition of type 1 of K n are given. 展开更多
关键词 complete n-partite graph decomposition of graph complete multipartite decomposition
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E-Total Coloring of Complete Bipartite Graphs K_(5,n)(5≤n≤7 113)Which Are Vertex-Distinguished by Multiple Sets
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作者 GUO Yaqin CHEN Xiang'en 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2024年第5期412-418,共7页
In this study,using the method of contradiction and the pre-assignment of chromatic sets,we discuss the E-total coloring of complete bipartite graphs K_(5,n)(5≤n≤7 113) which are vertex-distinguished by multiple set... In this study,using the method of contradiction and the pre-assignment of chromatic sets,we discuss the E-total coloring of complete bipartite graphs K_(5,n)(5≤n≤7 113) which are vertex-distinguished by multiple sets.The vertex-distinguishing E-total chromatic numbers of this kind of graph are determined. 展开更多
关键词 complete bipartite graph E-total coloring E-total chromatic number multiple sets chromatic sets
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How to implement a knowledge graph completeness assessment with the guidance of user requirements
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作者 ZHANG Ying XIAO Gang 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期679-688,共10页
In the context of big data, many large-scale knowledge graphs have emerged to effectively organize the explosive growth of web data on the Internet. To select suitable knowledge graphs for use from many knowledge grap... In the context of big data, many large-scale knowledge graphs have emerged to effectively organize the explosive growth of web data on the Internet. To select suitable knowledge graphs for use from many knowledge graphs, quality assessment is particularly important. As an important thing of quality assessment, completeness assessment generally refers to the ratio of the current data volume to the total data volume.When evaluating the completeness of a knowledge graph, it is often necessary to refine the completeness dimension by setting different completeness metrics to produce more complete and understandable evaluation results for the knowledge graph.However, lack of awareness of requirements is the most problematic quality issue. In the actual evaluation process, the existing completeness metrics need to consider the actual application. Therefore, to accurately recommend suitable knowledge graphs to many users, it is particularly important to develop relevant measurement metrics and formulate measurement schemes for completeness. In this paper, we will first clarify the concept of completeness, establish each metric of completeness, and finally design a measurement proposal for the completeness of knowledge graphs. 展开更多
关键词 knowledge graph completeness assessment relative completeness user requirement quality management
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Application of Multi-Relationship Perception Based on Graph Neural Network in Relationship Prediction
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作者 Shaoming Qiu Xinchen Huang +2 位作者 Liangyu Liu Bicong E Jingfeng Ye 《Computers, Materials & Continua》 2025年第6期5657-5678,共22页
Most existing knowledge graph relationship prediction methods are unable to capture the complex information of multi-relational knowledge graphs,thus overlooking key details contained in different entity pairs and mak... Most existing knowledge graph relationship prediction methods are unable to capture the complex information of multi-relational knowledge graphs,thus overlooking key details contained in different entity pairs and making it difficult to aggregate more complex relational features.Moreover,the insufficient capture of multi-hop relational information limits the processing capability of the global structure of the graph and reduces the accuracy of the knowledge graph completion task.This paper uses graph neural networks to construct new message functions for different relations,which can be defined as the rotation from the source entity to the target entity in the complex vector space for each relation,thereby improving the relation perception.To further enrich the relational diversity of different entities,we capture themulti-hop structural information in complex graph structure relations by incorporating two-hop relations for each entity and adding auxiliary edges to various relation combinations in the knowledge graph,thereby aggregating more complex relations and improving the reasoning ability of complex relational information.To verify the effectiveness of the proposed method,we conducted experiments on the WN18RR and FB15k-237 standard datasets.The results show that the method proposed in this study outperforms most existing methods. 展开更多
关键词 graph attention network relationship perception knowledge graph completion link prediction
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MMCSD:Multi-Modal Knowledge Graph Completion Based on Super-Resolution and Detailed Description Generation
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作者 Huansha Wang Ruiyang Huang +2 位作者 Qinrang Liu Shaomei Li Jianpeng Zhang 《Computers, Materials & Continua》 2025年第4期761-783,共23页
Multi-modal knowledge graph completion(MMKGC)aims to complete missing entities or relations in multi-modal knowledge graphs,thereby discovering more previously unknown triples.Due to the continuous growth of data and ... Multi-modal knowledge graph completion(MMKGC)aims to complete missing entities or relations in multi-modal knowledge graphs,thereby discovering more previously unknown triples.Due to the continuous growth of data and knowledge and the limitations of data sources,the visual knowledge within the knowledge graphs is generally of low quality,and some entities suffer from the issue of missing visual modality.Nevertheless,previous studies of MMKGC have primarily focused on how to facilitate modality interaction and fusion while neglecting the problems of low modality quality and modality missing.In this case,mainstream MMKGC models only use pre-trained visual encoders to extract features and transfer the semantic information to the joint embeddings through modal fusion,which inevitably suffers from problems such as error propagation and increased uncertainty.To address these problems,we propose a Multi-modal knowledge graph Completion model based on Super-resolution and Detailed Description Generation(MMCSD).Specifically,we leverage a pre-trained residual network to enhance the resolution and improve the quality of the visual modality.Moreover,we design multi-level visual semantic extraction and entity description generation,thereby further extracting entity semantics from structural triples and visual images.Meanwhile,we train a variational multi-modal auto-encoder and utilize a pre-trained multi-modal language model to complement the missing visual features.We conducted experiments on FB15K-237 and DB13K,and the results showed that MMCSD can effectively perform MMKGC and achieve state-of-the-art performance. 展开更多
关键词 Multi-modal knowledge graph knowledge graph completion multi-modal fusion
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Minimum Genus Embeddings of the Complete Graph
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作者 Zhao Xiang LI Han REN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2016年第10期1246-1254,共9页
In this paper, the problem of construction of exponentially many minimum genus crouchdings of complete graphs in surfaces are studied. There are three approaches to solve this problem. The first approach is to constru... In this paper, the problem of construction of exponentially many minimum genus crouchdings of complete graphs in surfaces are studied. There are three approaches to solve this problem. The first approach is to construct exponentially many graphs by the theory of graceful labeling of paths; the second approach is to find a current assignment of the current graph by the theory of current graph; the third approach is to find exponentially many embedding (or rotation) schemes of complete graph by finding exponentially many distinct maximum genus embeddings of the current graph. According to this three approaches, we can construct exponentially many minimum genus embeddings of complete graph K12s+8 in orientable surfaces, which show that there are at least 10/5 × (200/9)^s distinct minimum genus embeddings for K12s+8 in orientable surfaces. We have also proved that K12s+8 has at least 10/3× (200/9)^s distinct minimum genus embeddings in non-orientable surfaces. 展开更多
关键词 Maximum genus embedding minimum genus embedding complete graph current graph
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Exponentially Many Genus Embeddings of the Complete Graph K_(12s+3)
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作者 Zhao-xiang LI Han REN 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2015年第2期387-394,共8页
In this paper, we consider the problem of construction of exponentially many distinct genus embeddings of complete graphs. There are three approaches to solve the problem. The first approach is to construct exponentia... In this paper, we consider the problem of construction of exponentially many distinct genus embeddings of complete graphs. There are three approaches to solve the problem. The first approach is to construct exponentially many current graphs by the theory of graceful labellings of paths; the second approach is to find a current assignment of the current graph by the theory of current graph; the third approach is to find exponentially many embedding(or rotation) scheme of complete graph by finding exponentially many distinct maximum genus embeddings of the current graph. According to these three approaches, we can construct exponentially many distinct genus embeddings of complete graph K12s+3, which show that there are at least1/2× (200/9)s distinct genus embeddings for K12s+3. 展开更多
关键词 maximum genus embedding genus embedding complete graph current graph
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Phase transition for SIR model with random transition rates on complete graphs
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作者 Xiaofeng XUE 《Frontiers of Mathematics in China》 SCIE CSCD 2018年第3期667-690,共24页
We are concerned with the susceptible-infective-removed (SIR) model with random transition rates on complete graphs Cn with n vertices. We assign independent and identically distributed (i.i.d.) copies of a positi... We are concerned with the susceptible-infective-removed (SIR) model with random transition rates on complete graphs Cn with n vertices. We assign independent and identically distributed (i.i.d.) copies of a positive random variable ξ on each vertex as the recovery rates and i.i.d, copies of a positive random variable ρ on each edge as the edge infection weights. We assume that a susceptible vertex is infected by an infective one at rate proportional to the edge weight on the edge connecting these two vertices while an infective vertex becomes removed with rate equals the recovery rate on it, then we show that the model performs the following phase transition when at t = 0 one vertex is infective and others are susceptible. There exists λc 〉 0 such that when λ 〈 λc, the proportion r∞ of vertices which have ever been infective converges to 0 weakly as n → +∞ while when λ 〉 λc, there exist c(λ) 〉 0 and b(λ) 〉 0 such that for each n ≥ 1 with probability p ≥ b(λ), the proportion r∞ ≥ c(λ). Furthermore, we prove that Ac is the inverse of the production of the mean of p and the mean of the inverse of ξ. 展开更多
关键词 Susceptible-infective-removed (SIR) model complete graph phase transition random rate
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NK-Labeling of Graphs
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作者 Nasreen Almohanna Khawlah Alhulwah 《American Journal of Computational Mathematics》 2024年第4期391-400,共10页
A graph labeling is the assigning of labels to the vertices, edges, or both (usually non-negative integers), often satisfying some prescribed requirements. This terminology has become standard. A graph G's edges c... A graph labeling is the assigning of labels to the vertices, edges, or both (usually non-negative integers), often satisfying some prescribed requirements. This terminology has become standard. A graph G's edges can be colored by assigning a different color to each of its edges. The edge coloring is appropriate if adjacent edges are given different colors. In this work, we introduce a new labeling called NK-labeling. Let c:E(G)→ℕbe a proper edge coloring of G which induces a proper vertex coloring c′:V(G)→ℤndefined by c′(v)≡∑e∈Evc(e)modnSuch that Evis the set of edges incident with vin G. The minimum positive integer for which the graph G has NK-labeling called NK-chromatic index and denoted by χ′NK(G). We study the NK-labeling of several well-known classes of graphs. It is shown that the NK-chromatic of the path Pnfor n≥4is three and for odd n, the NK-chromatic of the complete graph Knis n. Other results dealing with the NK-labeling are also presented. 展开更多
关键词 graph Edge Coloring NK-Labeling LABEL Path CYCLE WHEEL complete graph
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Vertex-distinguishing E-total Coloring of Complete Bipartite Graph K 7,n when7≤n≤95 被引量:14
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作者 chen xiang-en du xian-kun 《Communications in Mathematical Research》 CSCD 2016年第4期359-374,共16页
Let G be a simple graph. A total coloring f of G is called an E-total coloring if no two adjacent vertices of G receive the same color, and no edge of G receives the same color as one of its endpoints.... Let G be a simple graph. A total coloring f of G is called an E-total coloring if no two adjacent vertices of G receive the same color, and no edge of G receives the same color as one of its endpoints. For an E-total coloring f of a graph G and any vertex x of G, let C(x) denote the set of colors of vertex x and of the edges incident with x, we call C(x) the color set of x. If C(u) ≠ C(v) for any two different vertices u and v of V (G), then we say that f is a vertex-distinguishing E-total coloring of G or a VDET coloring of G for short. The minimum number of colors required for a VDET coloring of G is denoted by Хvt^e(G) and is called the VDE T chromatic number of G. The VDET coloring of complete bipartite graph K7,n (7 ≤ n ≤ 95) is discussed in this paper and the VDET chromatic number of K7,n (7 ≤ n ≤ 95) has been obtained. 展开更多
关键词 graph complete bipartite graph E-total coloring vertex-distinguishingE-total coloring vertex-distinguishing E-total chromatic number
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Signless Laplacian Characteristic Polynomials of Complete Multipartite Graphs 被引量:7
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作者 LU Shi-fang ZHAO Hai-xing 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第1期36-40,共5页
For a simple graph G,let matrix Q(G)=D(G) + A(G) be it's signless Laplacian matrix and Q G (λ)=det(λI Q) it's signless Laplacian characteristic polynomial,where D(G) denotes the diagonal matrix of vertex deg... For a simple graph G,let matrix Q(G)=D(G) + A(G) be it's signless Laplacian matrix and Q G (λ)=det(λI Q) it's signless Laplacian characteristic polynomial,where D(G) denotes the diagonal matrix of vertex degrees of G,A(G) denotes its adjacency matrix of G.If all eigenvalues of Q G (λ) are integral,then the graph G is called Q-integral.In this paper,we obtain that the signless Laplacian characteristic polynomials of the complete multi-partite graphs G=K(n_1,n_2,···,n_t).We prove that the complete t-partite graphs K(n,n,···,n)t are Q-integral and give a necessary and sufficient condition for the complete multipartite graphs K(m,···,m)s(n,···,n)t to be Q-integral.We also obtain that the signless Laplacian characteristic polynomials of the complete multipartite graphs K(m,···,m,)s1(n,···,n,)s2(l,···,l)s3. 展开更多
关键词 the signless Laplacian spectrum the complete multipartite graphs the Qintegral
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Remarks on Vertex-Distinguishing IE-Total Coloring of Complete Bipartite Graphs K_(4,n) and K_(n,n) 被引量:4
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作者 Xiang'en CHEN Xiaoqing XIN Wenyu HE 《Journal of Mathematical Research with Applications》 CSCD 2012年第2期157-166,共10页
Let G be a simple graph. An IE-total coloring f of G refers to a coloring of the vertices and edges of G so that no two adjacent vertices receive the same color. Let C(u) be the set of colors of vertex u and edges i... Let G be a simple graph. An IE-total coloring f of G refers to a coloring of the vertices and edges of G so that no two adjacent vertices receive the same color. Let C(u) be the set of colors of vertex u and edges incident to u under f. For an IE-total coloring f of G using k colors, if C(u) =fi C(v) for any two different vertices u and v of V(G), then f is called a k-vertex-distinguishing IE-total-coloring of G, or a k-VDIET coloring of G for short. The ie iV., minimum number of colors required for a VDIET coloring of G is denoted by X,t[ 1, and it is called the VDIET chromatic number of G. We will give VDIET chromatic numbers for complete bipartite graph K4,n(n ≥ 4), Kn,n (5 ≤ n ≤21) in this article. 展开更多
关键词 graphS IE-total coloring vertex-distinguishing IE-total coloring vertex-distinguishingIE-total chromatic number complete bipartite graph.
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Signed Roman (Total) Domination Numbers of Complete Bipartite Graphs and Wheels 被引量:4
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作者 ZHAO YAN-CAI MIAO LIAN-YING Du Xian-kun 《Communications in Mathematical Research》 CSCD 2017年第4期318-326,共9页
A signed(res. signed total) Roman dominating function, SRDF(res.STRDF) for short, of a graph G =(V, E) is a function f : V → {-1, 1, 2} satisfying the conditions that(i)∑v∈N[v]f(v) ≥ 1(res.∑v∈N(v)f(v) ≥ 1) for ... A signed(res. signed total) Roman dominating function, SRDF(res.STRDF) for short, of a graph G =(V, E) is a function f : V → {-1, 1, 2} satisfying the conditions that(i)∑v∈N[v]f(v) ≥ 1(res.∑v∈N(v)f(v) ≥ 1) for any v ∈ V, where N [v] is the closed neighborhood and N(v) is the neighborhood of v, and(ii) every vertex v for which f(v) =-1 is adjacent to a vertex u for which f(u) = 2. The weight of a SRDF(res. STRDF) is the sum of its function values over all vertices.The signed(res. signed total) Roman domination number of G is the minimum weight among all signed(res. signed total) Roman dominating functions of G. In this paper,we compute the exact values of the signed(res. signed total) Roman domination numbers of complete bipartite graphs and wheels. 展开更多
关键词 signed Roman domination signed total Roman domination complete bipartite graph WHEEL
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Vertex-distinguishing IE-total Colorings of Complete Bipartite Graphs K8,n 被引量:3
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作者 SHI Jin CHEN Xiang-en 《Chinese Quarterly Journal of Mathematics》 2016年第2期147-154,共8页
Let G be a simple graph. An IE-total coloring f of G is a coloring of the vertices and edges of G so that no two adjacent vertices receive the same color. For each vertex x of G, let C(x) be the set of colors of verte... Let G be a simple graph. An IE-total coloring f of G is a coloring of the vertices and edges of G so that no two adjacent vertices receive the same color. For each vertex x of G, let C(x) be the set of colors of vertex x and edges incident to x under f. For an IE-total coloring f of G using k colors, if C(u) ≠ C(v) for any two different vertices u and v of G, then f is called a k-vertex-distinguishing IE-total-coloring of G or a k-VDIET coloring of G for short. The minimum number of colors required for a VDIET coloring of G is denoted by χ_(vt)^(ie) (G) and is called vertex-distinguishing IE-total chromatic number or the VDIET chromatic number of G for short. The VDIET colorings of complete bipartite graphs K_(8,n)are discussed in this paper. Particularly, the VDIET chromatic number of K_(8,n) are obtained. 展开更多
关键词 complete bipartite graphs IE-total coloring vertex-distinguishing IE-total coloring vertex-distinguishing IE-total chromatic number
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Distance Integral Complete Multipartite Graphs with s=5, 6 被引量:2
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作者 YANG Ruo-song WANG Li-gong 《Chinese Quarterly Journal of Mathematics》 2016年第2期111-117,共7页
Let D(G) =(d_(ij))_(n×n) denote the distance matrix of a connected graph G with order n, where d_(ij) is equal to the distance between vertices viand vjin G. A graph is called distance integral if all eigenvalues... Let D(G) =(d_(ij))_(n×n) denote the distance matrix of a connected graph G with order n, where d_(ij) is equal to the distance between vertices viand vjin G. A graph is called distance integral if all eigenvalues of its distance matrix are integers. In 2014, Yang and Wang gave a sufficient and necessary condition for complete r-partite graphs K_(p1,p2,···,pr)=K_(a1·p1,a2·p2,···,as···ps) to be distance integral and obtained such distance integral graphs with s = 1, 2, 3, 4. However distance integral complete multipartite graphs K_(a1·p1,a2·p2,···,as·ps) with s > 4 have not been found. In this paper, we find and construct some infinite classes of these distance integral graphs K_(a1·p1,a2·p2,···,as·ps) with s = 5, 6. The problem of the existence of such distance integral graphs K_(a1·p1,a2·p2,···,as·ps) with arbitrarily large number s remains open. 展开更多
关键词 complete multipartite graph distance matrix distance integral graph spectrum
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Bondage and Reinforcement Number of γ_f for Complete Multipartite Graph
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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
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