With the development of information technology, the amount of power grid topology data has gradually increased. Therefore, accurate querying of this data has become particularly important. Several researchers have cho...With the development of information technology, the amount of power grid topology data has gradually increased. Therefore, accurate querying of this data has become particularly important. Several researchers have chosen different indexing methods in the filtering stage to obtain more optimized query results because currently there is no uniform and efficient indexing mechanism that achieves good query results. In the traditional algorithm, the hash table for index storage is prone to "collision" problems, which decrease the index construction efficiency. Aiming at the problem of quick index entry, based on the construction of frequent subgraph indexes, a method of serialized storage optimization based on multiple hash tables is proposed. This method mainly uses the exploration sequence to make the keywords evenly distributed; it avoids conflicts of the stored procedure and performs a quick search of the index. The proposed algorithm mainly adopts the "filterverify" mechanism; in the filtering stage, the index is first established offline, and then the frequent subgraphs are found using the "contains logic" rule to obtain the candidate set. Experimental results show that this method can reduce the time and scale of candidate set generation and improve query efficiency.展开更多
Bollobas and Gyarfas conjectured that for n 〉 4（k - 1） every 2-edge-coloring of Kn contains a monochromatic k-connected subgraph with at least n - 2k ＋ 2 vertices. Liu, et al. proved that the conjecture holds when...Bollobas and Gyarfas conjectured that for n 〉 4（k - 1） every 2-edge-coloring of Kn contains a monochromatic k-connected subgraph with at least n - 2k ＋ 2 vertices. Liu, et al. proved that the conjecture holds when n 〉 13k - 15. In this note, we characterize all the 2-edge-colorings of Kn where each monochromatic k-connected subgraph has at most n - 2k ＋ 2 vertices for n ≥ 13k - 15.展开更多
Mining subgraphs with interesting structural properties from networks (or graphs) is a computationally challenging task. In this paper, we propose two algorithms for enumerating all connected induced subgraphs of a gi...Mining subgraphs with interesting structural properties from networks (or graphs) is a computationally challenging task. In this paper, we propose two algorithms for enumerating all connected induced subgraphs of a given cardinality from networks (or connected undirected graphs in networks). The first algorithm is a variant of a previous wellknown algorithm. The algorithm enumerates all connected induced subgraphs of cardinality k in a bottom-up manner. Thedata structures that lead to unit time element checking and linear space are presented. Different from previous algorithmsthat work in either a bottom-up manner or a reverse search manner, an algorithm that enumerates all connected inducedsubgraphs of cardinality k in a top-down manner is proposed. The correctness and complexity of the top-down algorithmare theoretically analyzed and proven. In the experiments, we evaluate the efficiency of the algorithms using a set of realworld networks from various fields. Experimental results show that the variant bottom-up algorithm outperforms thestate-of-the-art algorithms for enumerating connected induced subgraphs of small cardinality, and the top-down algorithmcan achieve an order of magnitude speedup over the state-of-the-art algorithms for enumerating connected induced subgraphs of large cardinality.展开更多
The traditional game of cops and robbers is played on undirected graph. Recently, the same game played on directed graph is getting attention by more and more people. We knew that if we forbid some subgraph we can bou...The traditional game of cops and robbers is played on undirected graph. Recently, the same game played on directed graph is getting attention by more and more people. We knew that if we forbid some subgraph we can bound the cop number of the corresponding class of graphs. In this paper, we analyze the game of cops and robbers on H^(-)-free digraphs. However, it is not the same as the case of undirected graph. So we give a new concept(H^(-)^(*)-free digraph) to get a similar conclusion about the case of undirected graph.展开更多
One main challenge for simplifying node-link diagrams of large-scale social networks lies in that simplified graphs generally contain dense subgroups or cohesive subgraphs.Graph triangles quantify the solid and stable...One main challenge for simplifying node-link diagrams of large-scale social networks lies in that simplified graphs generally contain dense subgroups or cohesive subgraphs.Graph triangles quantify the solid and stable relationships that maintain cohesive subgraphs.Understanding the mechanism of triangles within cohesive subgraphs contributes to illuminating patterns of connections within social networks.However,prior works can hardly handle and visualize triangles in cohesive subgraphs.In this paper,we propose a triangle-based graph simplification approach that can filter and visualize cohesive subgraphs by leveraging a triangle-connectivity called k-truss and a force-directed algorithm.We design and implement TriGraph,a web-based visual interface that provides detailed information for exploring and analyzing social networks.Quantitative comparisons with existing methods,two case studies on real-world datasets,and feedback from domain experts demonstrate the effectiveness of TriGraph.展开更多
Rumor Control(RC),aimed at minimizing the spread of rumors in social networks,is of paramount importance,as the spread of rumors can lead to significant economic losses,societal disruptions,and even widespread panic.T...Rumor Control(RC),aimed at minimizing the spread of rumors in social networks,is of paramount importance,as the spread of rumors can lead to significant economic losses,societal disruptions,and even widespread panic.The RC problem has garnered extensive research attention,however,most existing solutions for rumor control face a trade-off between efficiency and effectiveness,which limits their practical application in real-world scenarios.In this light,this paper studies the Truth-spreading-based Rumor Control(TRC)problem,and introduces the Subgraphbased Greedy algorithm Optimized with CELF(SGOC),which employs subgraph techniques and the CELF strategy,as the basic solution for the TRC problem.To improve the performance of SGOC,we carefully design a shortest path length dictionary SPR and an Immune Nodes Set(INS),leading to the Shortest Path-Based Rumor Control(SPRC)algorithm.To further enhance the SPRC algorithm,we develop a pruning method that accelerates the construction process of INS,proposing the Improved Shortest Path-Based Rumor Control(ISPRC)algorithm,which demonstrates superior efficiency compared to both SPRC and SGOC.Extensive experiments conducted on five real-world datasets,demonstrate the effectiveness and efficiency of the proposed algorithms.展开更多
A graph is claw-free if it contains no induced subgraph isomorphic to a K1,3.This paper studies hamiltonicity in 3-connected claw-free graphs.Four generation of Shepherd’s result[4] are obtained.For example,we show t...A graph is claw-free if it contains no induced subgraph isomorphic to a K1,3.This paper studies hamiltonicity in 3-connected claw-free graphs.Four generation of Shepherd’s result[4] are obtained.For example,we show that if G is.3-connected claw-free graph and(1)if for each vertex V the set of venices at distance three from v doesn’tcontain and independent subset of size three,then G is hamiltonian;(2) if G contains no induced subgraph with degree sequence(1,1,1,2,2,2,3,3,3),so that ear vertel of degree is adjacent to a vertex of degree i + 1 for i=1,2,then G is hamiltonoan. Furthermore,we obtain a generalization of both(1) and(2),in which the graphs F1 and F2coatain an the known forbidded subgraphs given in[3] as indeced subgraphs.展开更多
An element may have heterogeneous semantic interpretations in different ontologies. Therefore, understanding the real local meanings of elements is very useful for ontology operations such as querying and reasoning, w...An element may have heterogeneous semantic interpretations in different ontologies. Therefore, understanding the real local meanings of elements is very useful for ontology operations such as querying and reasoning, which are the foundations for many applications including semantic searching, ontology matching, and linked data analysis. However, since different ontologies have different preferences to describe their elements, obtaining the semantic context of an element is an open problem. A semantic subgraph was proposed to capture the real meanings of ontology elements. To extract the semantic subgraphs, a hybrid ontology graph is used to represent the semantic relations between elements. An extracting algorithm based on an electrical circuit model is then used with new conductivity calculation rules to improve the quality of the semantic subgraphs. The evaluation results show that the semantic subgraphs properly capture the local meanings of elements. Ontology matching based on semantic subgraphs also demonstrates that the semantic subgraph is a promising technique for ontology applications.展开更多
The degree d(H)of a subgraph H of a graph G is|u∈∪V(H)N(u)-V(H)|,where N(u)denotes the neighbor set of the vertex u of G.In this paper,we prove the following result on the condition of the degrees of subgraphs.Let G...The degree d(H)of a subgraph H of a graph G is|u∈∪V(H)N(u)-V(H)|,where N(u)denotes the neighbor set of the vertex u of G.In this paper,we prove the following result on the condition of the degrees of subgraphs.Let G be a 2-connected claw-free graph of order n with minimum degreeδ(G)≥3.If for any three non-adjacent subgraphs H1,H2,H3 that are isomorphic to K1,K1,K2,respectively,there is d(H1)+d(H2)+d(H3)≥n+3,then for each pair of vertices u,v∈G that is not a cut set,there exists a Hamilton path between u and v.展开更多
A graph G is said to be embedded in a graph H, written, if there exists an isomorphism φ of G onto a subgraph G’ of H. Such an isomorphism φ is called an embedding of Ginto H. In 1982, D. Bauer and R. Tindell defin...A graph G is said to be embedded in a graph H, written, if there exists an isomorphism φ of G onto a subgraph G’ of H. Such an isomorphism φ is called an embedding of Ginto H. In 1982, D. Bauer and R. Tindell defined an invariant for graphs G, G neither a path nor K1,3, by setting ∧（G） equal to the least n≥1 for which GL*（G）. They have studied graphs with ∧ （G）=1, and posed questions of studying graphs with ∧ （G）=2 and of determining ∧（T） for all trees T. We have also studied the questions and have further studied graphs G such that G embeds in its iterated line-graph Ln（G）.展开更多
A graph is called claw-free if it contains no induced subgrapn lsomorpmc to K1,3. Matthews and Sumner proved that a 2-connected claw-free graph G is Hamiltonian if every vertex of it has degree at least （[V（G）I - 2...A graph is called claw-free if it contains no induced subgrapn lsomorpmc to K1,3. Matthews and Sumner proved that a 2-connected claw-free graph G is Hamiltonian if every vertex of it has degree at least （[V（G）I - 2）/3. At the workshop CSzC （Novy Smokovec, 1993）, Broersma conjectured the degree condition of this result can be restricted only to end-vertices of induced copies of N （the graph obtained from a triangle by adding three disjoint pendant edges）. Fujisawa and Yamashita showed that the degree condition of Matthews and Sumner can be restricted only to end-vertices of induced copies of Z1 （the graph obtained from a triangle by adding one pendant edge）. Our main result in this paper is a characterization of all graphs H such that a 2-connected claw-free graph G is Hamiltonian if eachend-vertex of every induced copy of H in G has degree at least IV（G）I/3 ＋ 1. This gives an affirmative solution of the conjecture of Broersma up to an additive constant.end-vertex of every induced copy of H in G has degree at least IV（G）I/3 ＋ 1. This gives an affirmative solution of the conjecture of Broersma up to an additive constant.展开更多
Real-world networks,such as social networks,cryptocurrency networks,and e-commerce networks,always have occurrence time of interactions between nodes.Such networks are typically modeled as temporal graphs.Mining cohes...Real-world networks,such as social networks,cryptocurrency networks,and e-commerce networks,always have occurrence time of interactions between nodes.Such networks are typically modeled as temporal graphs.Mining cohesive subgraphs from temporal graphs is practical and essential in numerous data mining applications,since mining cohesive subgraphs gets insights into the time-varying nature of temporal graphs.However,existing studies on mining cohesive subgraphs,such as Densest-Exact and k-truss,are mainly tailored for static graphs(whose edges have no temporal information).Therefore,those cohesive subgraph models cannot indicate both the temporal and the structural characteristics of subgraphs.To this end,we explore the model of cohesive temporal subgraphs by incorporating both the evolving and the structural characteristics of temporal subgraphs.Unfortunately,the volume of time intervals in a temporal network is quadratic.As a result,the time complexity of mining temporal cohesive subgraphs is high.To efficiently address the problem,we first mine the temporal density distribution of temporal graphs.Guided by the distribution,we can safely prune many unqualified time intervals with the linear time cost.Then,the remaining time intervals where cohesive temporal subgraphs fall in are examined using the greedy search.The results of the experiments on nine real-world temporal graphs indicate that our model outperforms state-of-the-art solutions in efficiency and quality.Specifically,our model only takes less than two minutes on a million-vertex DBLP and has the highest overall average ranking in EDB and TC metrics.展开更多
We propose to use discriminative subgraphs to discover family photos from group photos in an efficient and effective way. Group photos are represented as face graphs by identifying social contexts such as age, gender,...We propose to use discriminative subgraphs to discover family photos from group photos in an efficient and effective way. Group photos are represented as face graphs by identifying social contexts such as age, gender, and face position. The previous work utilized bag-of-word models and considered frequent subgraphs from all group photos as features for classification. This approach, however, produces numerous subgraphs, resulting in high dimensions.Furthermore, some of them are not discriminative.To solve these issues, we adopt a state-of-the-art,frequent subgraph mining method that removes nondiscriminative subgraphs. We also use TF-IDF normalization, which is more suitable for the bag-ofword model. To validate our method, we experiment in two datasets. Our method shows consistently better performance, higher accuracy in lower feature dimensions, compared to the previous method. We also integrate our method with the recent Microsoft face recognition API and release it in a public website.展开更多
Social robot accounts controlled by artificial intelligence or humans are active in social networks,bringing negative impacts to network security and social life.Existing social robot detection methods based on graph ...Social robot accounts controlled by artificial intelligence or humans are active in social networks,bringing negative impacts to network security and social life.Existing social robot detection methods based on graph neural networks suffer from the problem of many social network nodes and complex relationships,which makes it difficult to accurately describe the difference between the topological relations of nodes,resulting in low detection accuracy of social robots.This paper proposes a social robot detection method with the use of an improved neural network.First,social relationship subgraphs are constructed by leveraging the user’s social network to disentangle intricate social relationships effectively.Then,a linear modulated graph attention residual network model is devised to extract the node and network topology features of the social relation subgraph,thereby generating comprehensive social relation subgraph features,and the feature-wise linear modulation module of the model can better learn the differences between the nodes.Next,user text content and behavioral gene sequences are extracted to construct social behavioral features combined with the social relationship subgraph features.Finally,social robots can be more accurately identified by combining user behavioral and relationship features.By carrying out experimental studies based on the publicly available datasets TwiBot-20 and Cresci-15,the suggested method’s detection accuracies can achieve 86.73%and 97.86%,respectively.Compared with the existing mainstream approaches,the accuracy of the proposed method is 2.2%and 1.35%higher on the two datasets.The results show that the method proposed in this paper can effectively detect social robots and maintain a healthy ecological environment of social networks.展开更多
MATLAB software and optimal complete subgraph algorithm were used to extract and reveal the microsatellite distribution features in the complete genomes of the tobacco vein clearing virus （NC-003 378.1） from the NCB...MATLAB software and optimal complete subgraph algorithm were used to extract and reveal the microsatellite distribution features in the complete genomes of the tobacco vein clearing virus （NC-003 378.1） from the NCBI database.The results showed that the repetitions number and their location of the N-base group has been extracted and displayed.The largest repetitions of N-base group in the complete genomes of the tobacco vein clearing virus was decreased as the exponential function with the increasing of N.The method used in this study could be applied to the extraction and revealing of the microsatellite distribution features in the complete genomes of other viruses,thereby provided a basis for the research of the structure and the law of function,inheritance and variation by the using of the microsatellite distribution features.展开更多
In this article, we are interested in solving a combinatorial optimization problem, the shortest path problem in a multi-attribute graph, by the out-ranking methods. A multi-attribute graph has simultaneously qualitat...In this article, we are interested in solving a combinatorial optimization problem, the shortest path problem in a multi-attribute graph, by the out-ranking methods. A multi-attribute graph has simultaneously qualitative and quantitative criteria. This situation gives rise to incomparable paths thus forming the Pareto front. Outranking methods in Multi-criteria Decision Making (MCDM) are the only methods that can take into account this situation (incomparability of actions). After presenting the categories of Multi-criteria Decision Making (MCDM) and the difficulties related to the problems of the shortest paths, we propose an evolutionary algorithm based on the outranking methods to solve the problem of finding “best” paths in a multi-attribute graph with non-additive criteria. Our approach is based on the exploration of induced subgraphs of the outranking graph. Properties have been established to serve as algorithmic basis. Numerical experiments have been carried out and the results presented in this article.展开更多
The generating function for generating integer sequence of Aunu numbers of prime cardinality was reported earlier by the author in [1]. This paper assigns an operator on the function for where the op...The generating function for generating integer sequence of Aunu numbers of prime cardinality was reported earlier by the author in [1]. This paper assigns an operator on the function for where the operation induces addition or subtraction on the pairs of ai, aj elements which are consecutive pairs of elements obtained from a generating set of some finite order. The paper identifies that the set of the generated pairs of integer sequence is non-associative. The paper also presents the graph theoretic applications of the integers generated in which subgraphs are deduced from the main graph and adjacency matrices and incidence matrices constructed. It was also established that some of the subgraphs were found to be regular graphs. The findings in this paper can further be used in coding theory, Boolean algebra and circuit designs.展开更多
The product functional confguration(PFC)is typically used by frms to satisfy the individual requirements of customers and is realized based on market analysis.This study aims to help frms analyze functions and realize...The product functional confguration(PFC)is typically used by frms to satisfy the individual requirements of customers and is realized based on market analysis.This study aims to help frms analyze functions and realize functional confgurations using patent data.This study frst proposes a patent-data-driven PFC method based on a hypergraph network.It then constructs a weighted network model to optimize the combination of product function quantity and object from the perspective of big data,as follows:(1)The functional knowledge contained in the patent is extracted.(2)The functional hypergraph is constructed based on the co-occurrence relationship between patents and applicants.(3)The function and patent weight are calculated from the patent applicant’s perspective and patent value.(4)A weight calculation model of the PFC is developed.(5)The weighted frequent subgraph algorithm is used to obtain the optimal function combination list.This method is applied to an innovative design process of a bathroom shower.The results indicate that this method can help frms detach optimal function candidates and develop a multifunctional product.展开更多
The idea of positional inverted index is exploited for indexing of graph database. The main idea is the use of hashing tables in order to prune a considerable portion of graph database that cannot contain the answer s...The idea of positional inverted index is exploited for indexing of graph database. The main idea is the use of hashing tables in order to prune a considerable portion of graph database that cannot contain the answer set. These tables are implemented using column-based techniques and are used to store graphs of database, frequent sub-graphs and the neighborhood of nodes. In order to exact checking of remaining graphs, the vertex invariant is used for isomorphism test which can be parallel implemented. The results of evaluation indicate that proposed method outperforms existing methods.展开更多
The identification of design pattern instances is important for program understanding and software maintenance. Aiming at the mining of design patterns in existing systems, this paper proposes a subgraph isomorphism a...The identification of design pattern instances is important for program understanding and software maintenance. Aiming at the mining of design patterns in existing systems, this paper proposes a subgraph isomorphism approach to discover several design patterns in a legacy system at a time. The attributed relational graph is used to describe design patterns and legacy systems. The sub-graph isomorphism approach consists of decomposition and composition process. During the decomposition process, graphs corresponding to the design patterns are decomposed into sub-graphs, some of which are graphs corresponding to the elemental design patterns. The composition process tries to get sub-graph isomorphism of the matched graph if sub-graph isomorphism of each subgraph is obtained. Due to the common structures between design patterns, the proposed approach can reduce the matching times of entities and relations. Compared with the existing methods, the proposed algorithm is not linearly dependent on the number of design pattern graphs. Key words design pattern mining - attributed relational graph - subgraph isomorphism CLC number TP 311.5 Foundation item: Supported by the National Natural Science Foundation of China (60273075) and the Science Foundation of Naval University of Engineering (HGDJJ03019)Biography: LI Qing-hua (1940-), male, Professor, research direction: parallel computing.展开更多
基金supported by the State Grid Science and Technology Project (Title: Research on High Performance Analysis Technology of Power Grid GIS Topology Based on Graph Database, 5455HJ160005)
文摘With the development of information technology, the amount of power grid topology data has gradually increased. Therefore, accurate querying of this data has become particularly important. Several researchers have chosen different indexing methods in the filtering stage to obtain more optimized query results because currently there is no uniform and efficient indexing mechanism that achieves good query results. In the traditional algorithm, the hash table for index storage is prone to "collision" problems, which decrease the index construction efficiency. Aiming at the problem of quick index entry, based on the construction of frequent subgraph indexes, a method of serialized storage optimization based on multiple hash tables is proposed. This method mainly uses the exploration sequence to make the keywords evenly distributed; it avoids conflicts of the stored procedure and performs a quick search of the index. The proposed algorithm mainly adopts the "filterverify" mechanism; in the filtering stage, the index is first established offline, and then the frequent subgraphs are found using the "contains logic" rule to obtain the candidate set. Experimental results show that this method can reduce the time and scale of candidate set generation and improve query efficiency.
基金Supported by the National Natural Science Foundation of China(10701065 and 11101378)Zhejiang Provincial Natural Science Foundation(LY14A010009)
文摘Bollobas and Gyarfas conjectured that for n 〉 4（k - 1） every 2-edge-coloring of Kn contains a monochromatic k-connected subgraph with at least n - 2k ＋ 2 vertices. Liu, et al. proved that the conjecture holds when n 〉 13k - 15. In this note, we characterize all the 2-edge-colorings of Kn where each monochromatic k-connected subgraph has at most n - 2k ＋ 2 vertices for n ≥ 13k - 15.
基金supported by the National Natural Science Foundation of China under Grant No.61404069the Scientific Research Project of Colleges and Universities in Guangdong Province of China under Grant No.2021ZDZX1027+1 种基金the Guangdong Basic and Applied Basic Research Foundation under Grant Nos.2022A1515110712 and 2023A1515010077the STU Scientific Research Foundation for Talents under Grant Nos.NTF20016 and NTF20017.
文摘Mining subgraphs with interesting structural properties from networks (or graphs) is a computationally challenging task. In this paper, we propose two algorithms for enumerating all connected induced subgraphs of a given cardinality from networks (or connected undirected graphs in networks). The first algorithm is a variant of a previous wellknown algorithm. The algorithm enumerates all connected induced subgraphs of cardinality k in a bottom-up manner. Thedata structures that lead to unit time element checking and linear space are presented. Different from previous algorithmsthat work in either a bottom-up manner or a reverse search manner, an algorithm that enumerates all connected inducedsubgraphs of cardinality k in a top-down manner is proposed. The correctness and complexity of the top-down algorithmare theoretically analyzed and proven. In the experiments, we evaluate the efficiency of the algorithms using a set of realworld networks from various fields. Experimental results show that the variant bottom-up algorithm outperforms thestate-of-the-art algorithms for enumerating connected induced subgraphs of small cardinality, and the top-down algorithmcan achieve an order of magnitude speedup over the state-of-the-art algorithms for enumerating connected induced subgraphs of large cardinality.
文摘The traditional game of cops and robbers is played on undirected graph. Recently, the same game played on directed graph is getting attention by more and more people. We knew that if we forbid some subgraph we can bound the cop number of the corresponding class of graphs. In this paper, we analyze the game of cops and robbers on H^(-)-free digraphs. However, it is not the same as the case of undirected graph. So we give a new concept(H^(-)^(*)-free digraph) to get a similar conclusion about the case of undirected graph.
基金supported by National Natural Science Foundation of China(62132017)Fundamental Research Funds for the Central Universities,China(226-2022-00235).
文摘One main challenge for simplifying node-link diagrams of large-scale social networks lies in that simplified graphs generally contain dense subgroups or cohesive subgraphs.Graph triangles quantify the solid and stable relationships that maintain cohesive subgraphs.Understanding the mechanism of triangles within cohesive subgraphs contributes to illuminating patterns of connections within social networks.However,prior works can hardly handle and visualize triangles in cohesive subgraphs.In this paper,we propose a triangle-based graph simplification approach that can filter and visualize cohesive subgraphs by leveraging a triangle-connectivity called k-truss and a force-directed algorithm.We design and implement TriGraph,a web-based visual interface that provides detailed information for exploring and analyzing social networks.Quantitative comparisons with existing methods,two case studies on real-world datasets,and feedback from domain experts demonstrate the effectiveness of TriGraph.
基金partially supported by Research Programs of Henan Science and Technology Department(252102210022,232102210054)Henan Province Key Research and Development Project(231111212000)+2 种基金Henan Center for Out-standingOverseas Scientists(GZS2022011)Henan Province Collaborative Innovation Center of Aeronautics and Astronautics Electronic Information TechnologyHenan International Joint Laboratory of Aerospace Intelligent Technology and Systems.
文摘Rumor Control(RC),aimed at minimizing the spread of rumors in social networks,is of paramount importance,as the spread of rumors can lead to significant economic losses,societal disruptions,and even widespread panic.The RC problem has garnered extensive research attention,however,most existing solutions for rumor control face a trade-off between efficiency and effectiveness,which limits their practical application in real-world scenarios.In this light,this paper studies the Truth-spreading-based Rumor Control(TRC)problem,and introduces the Subgraphbased Greedy algorithm Optimized with CELF(SGOC),which employs subgraph techniques and the CELF strategy,as the basic solution for the TRC problem.To improve the performance of SGOC,we carefully design a shortest path length dictionary SPR and an Immune Nodes Set(INS),leading to the Shortest Path-Based Rumor Control(SPRC)algorithm.To further enhance the SPRC algorithm,we develop a pruning method that accelerates the construction process of INS,proposing the Improved Shortest Path-Based Rumor Control(ISPRC)algorithm,which demonstrates superior efficiency compared to both SPRC and SGOC.Extensive experiments conducted on five real-world datasets,demonstrate the effectiveness and efficiency of the proposed algorithms.
文摘A graph is claw-free if it contains no induced subgraph isomorphic to a K1,3.This paper studies hamiltonicity in 3-connected claw-free graphs.Four generation of Shepherd’s result[4] are obtained.For example,we show that if G is.3-connected claw-free graph and(1)if for each vertex V the set of venices at distance three from v doesn’tcontain and independent subset of size three,then G is hamiltonian;(2) if G contains no induced subgraph with degree sequence(1,1,1,2,2,2,3,3,3),so that ear vertel of degree is adjacent to a vertex of degree i + 1 for i=1,2,then G is hamiltonoan. Furthermore,we obtain a generalization of both(1) and(2),in which the graphs F1 and F2coatain an the known forbidded subgraphs given in[3] as indeced subgraphs.
基金Supported by the National High-Tech Research and Development (863) Program of China (No.2009AA01Z147)the National Natural Science Foundation of China (Nos.61003156 and 90818027)the National Key Basic Research and Development (973) Program of China (No.2009CB320703)
文摘An element may have heterogeneous semantic interpretations in different ontologies. Therefore, understanding the real local meanings of elements is very useful for ontology operations such as querying and reasoning, which are the foundations for many applications including semantic searching, ontology matching, and linked data analysis. However, since different ontologies have different preferences to describe their elements, obtaining the semantic context of an element is an open problem. A semantic subgraph was proposed to capture the real meanings of ontology elements. To extract the semantic subgraphs, a hybrid ontology graph is used to represent the semantic relations between elements. An extracting algorithm based on an electrical circuit model is then used with new conductivity calculation rules to improve the quality of the semantic subgraphs. The evaluation results show that the semantic subgraphs properly capture the local meanings of elements. Ontology matching based on semantic subgraphs also demonstrates that the semantic subgraph is a promising technique for ontology applications.
基金supported by the National Natural Science Foundation of China(No.11871398)the Natural Science Basic Research Plan in Shaanxi Province of China(Program No.2018JM1032)+1 种基金the Fundamental Research Funds for the Central Universities(No.3102019ghjd003)the Seed Foundation of Innovation and Creation for Graduate Students in Northwestern Polytechnical University(No.ZZ2019031)
文摘The degree d(H)of a subgraph H of a graph G is|u∈∪V(H)N(u)-V(H)|,where N(u)denotes the neighbor set of the vertex u of G.In this paper,we prove the following result on the condition of the degrees of subgraphs.Let G be a 2-connected claw-free graph of order n with minimum degreeδ(G)≥3.If for any three non-adjacent subgraphs H1,H2,H3 that are isomorphic to K1,K1,K2,respectively,there is d(H1)+d(H2)+d(H3)≥n+3,then for each pair of vertices u,v∈G that is not a cut set,there exists a Hamilton path between u and v.
文摘A graph G is said to be embedded in a graph H, written, if there exists an isomorphism φ of G onto a subgraph G’ of H. Such an isomorphism φ is called an embedding of Ginto H. In 1982, D. Bauer and R. Tindell defined an invariant for graphs G, G neither a path nor K1,3, by setting ∧（G） equal to the least n≥1 for which GL*（G）. They have studied graphs with ∧ （G）=1, and posed questions of studying graphs with ∧ （G）=2 and of determining ∧（T） for all trees T. We have also studied the questions and have further studied graphs G such that G embeds in its iterated line-graph Ln（G）.
基金Supported by NSFC(Grant Nos.11271300 and 11571135)the project NEXLIZ–CZ.1.07/2.3.00/30.0038+1 种基金the project P202/12/G061 of the Czech Science Foundation and by the European Regional Development Fund(ERDF)the project NTIS-New Technologies for Information Society,European Centre of Excellence,CZ.1.05/1.1.00/02.0090
文摘A graph is called claw-free if it contains no induced subgrapn lsomorpmc to K1,3. Matthews and Sumner proved that a 2-connected claw-free graph G is Hamiltonian if every vertex of it has degree at least （[V（G）I - 2）/3. At the workshop CSzC （Novy Smokovec, 1993）, Broersma conjectured the degree condition of this result can be restricted only to end-vertices of induced copies of N （the graph obtained from a triangle by adding three disjoint pendant edges）. Fujisawa and Yamashita showed that the degree condition of Matthews and Sumner can be restricted only to end-vertices of induced copies of Z1 （the graph obtained from a triangle by adding one pendant edge）. Our main result in this paper is a characterization of all graphs H such that a 2-connected claw-free graph G is Hamiltonian if eachend-vertex of every induced copy of H in G has degree at least IV（G）I/3 ＋ 1. This gives an affirmative solution of the conjecture of Broersma up to an additive constant.end-vertex of every induced copy of H in G has degree at least IV（G）I/3 ＋ 1. This gives an affirmative solution of the conjecture of Broersma up to an additive constant.
基金The work was supported by the National Key Research and Development Program of China under Grant No.2018YFB1402802the National Natural Science Foundation of China under Grant Nos.61932004 and 62072205.
文摘Real-world networks,such as social networks,cryptocurrency networks,and e-commerce networks,always have occurrence time of interactions between nodes.Such networks are typically modeled as temporal graphs.Mining cohesive subgraphs from temporal graphs is practical and essential in numerous data mining applications,since mining cohesive subgraphs gets insights into the time-varying nature of temporal graphs.However,existing studies on mining cohesive subgraphs,such as Densest-Exact and k-truss,are mainly tailored for static graphs(whose edges have no temporal information).Therefore,those cohesive subgraph models cannot indicate both the temporal and the structural characteristics of subgraphs.To this end,we explore the model of cohesive temporal subgraphs by incorporating both the evolving and the structural characteristics of temporal subgraphs.Unfortunately,the volume of time intervals in a temporal network is quadratic.As a result,the time complexity of mining temporal cohesive subgraphs is high.To efficiently address the problem,we first mine the temporal density distribution of temporal graphs.Guided by the distribution,we can safely prune many unqualified time intervals with the linear time cost.Then,the remaining time intervals where cohesive temporal subgraphs fall in are examined using the greedy search.The results of the experiments on nine real-world temporal graphs indicate that our model outperforms state-of-the-art solutions in efficiency and quality.Specifically,our model only takes less than two minutes on a million-vertex DBLP and has the highest overall average ranking in EDB and TC metrics.
基金supported in part by MSIP/IITP (Nos. R0126-16-1108, R0101-16-0176)MSIP/NRF (No. 2013-067321)
文摘We propose to use discriminative subgraphs to discover family photos from group photos in an efficient and effective way. Group photos are represented as face graphs by identifying social contexts such as age, gender, and face position. The previous work utilized bag-of-word models and considered frequent subgraphs from all group photos as features for classification. This approach, however, produces numerous subgraphs, resulting in high dimensions.Furthermore, some of them are not discriminative.To solve these issues, we adopt a state-of-the-art,frequent subgraph mining method that removes nondiscriminative subgraphs. We also use TF-IDF normalization, which is more suitable for the bag-ofword model. To validate our method, we experiment in two datasets. Our method shows consistently better performance, higher accuracy in lower feature dimensions, compared to the previous method. We also integrate our method with the recent Microsoft face recognition API and release it in a public website.
基金This work was supported in part by the National Natural Science Foundation of China under Grants 62273272,62303375 and 61873277in part by the Key Research and Development Program of Shaanxi Province under Grant 2023-YBGY-243+2 种基金in part by the Natural Science Foundation of Shaanxi Province under Grants 2022JQ-606 and 2020-JQ758in part by the Research Plan of Department of Education of Shaanxi Province under Grant 21JK0752in part by the Youth Innovation Team of Shaanxi Universities.
文摘Social robot accounts controlled by artificial intelligence or humans are active in social networks,bringing negative impacts to network security and social life.Existing social robot detection methods based on graph neural networks suffer from the problem of many social network nodes and complex relationships,which makes it difficult to accurately describe the difference between the topological relations of nodes,resulting in low detection accuracy of social robots.This paper proposes a social robot detection method with the use of an improved neural network.First,social relationship subgraphs are constructed by leveraging the user’s social network to disentangle intricate social relationships effectively.Then,a linear modulated graph attention residual network model is devised to extract the node and network topology features of the social relation subgraph,thereby generating comprehensive social relation subgraph features,and the feature-wise linear modulation module of the model can better learn the differences between the nodes.Next,user text content and behavioral gene sequences are extracted to construct social behavioral features combined with the social relationship subgraph features.Finally,social robots can be more accurately identified by combining user behavioral and relationship features.By carrying out experimental studies based on the publicly available datasets TwiBot-20 and Cresci-15,the suggested method’s detection accuracies can achieve 86.73%and 97.86%,respectively.Compared with the existing mainstream approaches,the accuracy of the proposed method is 2.2%and 1.35%higher on the two datasets.The results show that the method proposed in this paper can effectively detect social robots and maintain a healthy ecological environment of social networks.
基金Supported by the Eleventh Five-year Development Planning Project for Instructional Science in Hubei Province (2006B131)~~
文摘MATLAB software and optimal complete subgraph algorithm were used to extract and reveal the microsatellite distribution features in the complete genomes of the tobacco vein clearing virus （NC-003 378.1） from the NCBI database.The results showed that the repetitions number and their location of the N-base group has been extracted and displayed.The largest repetitions of N-base group in the complete genomes of the tobacco vein clearing virus was decreased as the exponential function with the increasing of N.The method used in this study could be applied to the extraction and revealing of the microsatellite distribution features in the complete genomes of other viruses,thereby provided a basis for the research of the structure and the law of function,inheritance and variation by the using of the microsatellite distribution features.
文摘In this article, we are interested in solving a combinatorial optimization problem, the shortest path problem in a multi-attribute graph, by the out-ranking methods. A multi-attribute graph has simultaneously qualitative and quantitative criteria. This situation gives rise to incomparable paths thus forming the Pareto front. Outranking methods in Multi-criteria Decision Making (MCDM) are the only methods that can take into account this situation (incomparability of actions). After presenting the categories of Multi-criteria Decision Making (MCDM) and the difficulties related to the problems of the shortest paths, we propose an evolutionary algorithm based on the outranking methods to solve the problem of finding “best” paths in a multi-attribute graph with non-additive criteria. Our approach is based on the exploration of induced subgraphs of the outranking graph. Properties have been established to serve as algorithmic basis. Numerical experiments have been carried out and the results presented in this article.
文摘The generating function for generating integer sequence of Aunu numbers of prime cardinality was reported earlier by the author in [1]. This paper assigns an operator on the function for where the operation induces addition or subtraction on the pairs of ai, aj elements which are consecutive pairs of elements obtained from a generating set of some finite order. The paper identifies that the set of the generated pairs of integer sequence is non-associative. The paper also presents the graph theoretic applications of the integers generated in which subgraphs are deduced from the main graph and adjacency matrices and incidence matrices constructed. It was also established that some of the subgraphs were found to be regular graphs. The findings in this paper can further be used in coding theory, Boolean algebra and circuit designs.
基金Supported by National Natural Science Foundation of China(Grant No.51875220)China Fujian Province Social Science Foundation Research Project(Grant No.FJ2021B128).
文摘The product functional confguration(PFC)is typically used by frms to satisfy the individual requirements of customers and is realized based on market analysis.This study aims to help frms analyze functions and realize functional confgurations using patent data.This study frst proposes a patent-data-driven PFC method based on a hypergraph network.It then constructs a weighted network model to optimize the combination of product function quantity and object from the perspective of big data,as follows:(1)The functional knowledge contained in the patent is extracted.(2)The functional hypergraph is constructed based on the co-occurrence relationship between patents and applicants.(3)The function and patent weight are calculated from the patent applicant’s perspective and patent value.(4)A weight calculation model of the PFC is developed.(5)The weighted frequent subgraph algorithm is used to obtain the optimal function combination list.This method is applied to an innovative design process of a bathroom shower.The results indicate that this method can help frms detach optimal function candidates and develop a multifunctional product.
文摘The idea of positional inverted index is exploited for indexing of graph database. The main idea is the use of hashing tables in order to prune a considerable portion of graph database that cannot contain the answer set. These tables are implemented using column-based techniques and are used to store graphs of database, frequent sub-graphs and the neighborhood of nodes. In order to exact checking of remaining graphs, the vertex invariant is used for isomorphism test which can be parallel implemented. The results of evaluation indicate that proposed method outperforms existing methods.
文摘The identification of design pattern instances is important for program understanding and software maintenance. Aiming at the mining of design patterns in existing systems, this paper proposes a subgraph isomorphism approach to discover several design patterns in a legacy system at a time. The attributed relational graph is used to describe design patterns and legacy systems. The sub-graph isomorphism approach consists of decomposition and composition process. During the decomposition process, graphs corresponding to the design patterns are decomposed into sub-graphs, some of which are graphs corresponding to the elemental design patterns. The composition process tries to get sub-graph isomorphism of the matched graph if sub-graph isomorphism of each subgraph is obtained. Due to the common structures between design patterns, the proposed approach can reduce the matching times of entities and relations. Compared with the existing methods, the proposed algorithm is not linearly dependent on the number of design pattern graphs. Key words design pattern mining - attributed relational graph - subgraph isomorphism CLC number TP 311.5 Foundation item: Supported by the National Natural Science Foundation of China (60273075) and the Science Foundation of Naval University of Engineering (HGDJJ03019)Biography: LI Qing-hua (1940-), male, Professor, research direction: parallel computing.
