Ranking the spreading ability of nodes in complex networks based on local structure
Introduction
The study of the spreading process on complex networks has drawn much attention recently because of its great theoretical significance and remarkable practical value in many areas including epidemic controlling [1], [2], [3], [4], [5], information dissemination [6], [7] and viral marketing [8], [9] etc. One of the fundamental problems in understanding and controlling spreading process is evaluating the spreading ability for each node in the network, i.e. how many nodes will finally be covered when the spreading origins from this single node [10], [11], [12], [13], [14], [15], [16]. The knowledge of node’s spreading ability shows new insights for applications such as finding social leaders [17], ranking reputation of scientists, publications [18] and designing efficient methods to either hinder epidemic spreading or accelerate information dissemination.
Over the recent years, various centrality measures such as degree, betweenness [19], closeness [20] and eigenvector [21] centralities have been proposed to rank nodes in the network. Degree centrality is a simple and efficient local metric, but it is less relevant since it neglects the global structure of the network. Some well-known global metrics such as betweenness centrality and closeness centrality can give better results. However due to their high computational complexity, they are incapable to be applied in large-scale networks. Recently, Kitsak et al. found that the most efficient spreaders are those located within the core of the network as identified by the -shell decomposition analysis [10]. After this, some modified network decomposition algorithms have been introduced to further improve the ranking performance [16], [22]. In directed networks, several iterative process based ranking methods such as PageRank [23], HITS [24] and LeaderRank [17] have been proposed to rank nodes.
Since the scale of online social systems keep growing, they can have millions or even billions of user, e.g. the total number of monthly active Facebook users is 1.1 billion till June 2013.1 Thus the ranking algorithms which are based on global information of the network will be very time-consuming and incapable to be applied. Hence, in order to rank nodes effectively and efficiently, it is better to design the ranking algorithms based on the local information of the network. For example, a semi-local centrality measure which considers both the nearest and the next nearest neighbors of a node has been proposed in Ref. [11]. This centrality measure has been shown to well rank the spreading ability of nodes and achieves a good tradeoff between low-relevant degree centrality and other time-consuming measures.
However, when the local centrality is used to rank nodes, only the number of the nearest and the next nearest neighbors of a node is considered, while the topological connections among the neighbors are completely ignored. Actually, the topological connections among the neighbors are also very important. For nodes with the same local centrality, the one with denser connected neighbors is supposed to have stronger spreading ability since denser connected neighbors get more chance to influence each other. Inspired by this idea, we propose a local structural centrality measure which considers both the number and the topological connections of node’s neighbors, where the local clustering coefficient of a node is used to measure the topological connections among its neighbors. We use the susceptible–infected–recovered (SIR) model [25] to simulate the epidemic spreading process on both artificial and real networks. By measuring the rank correlation between the ranked list generated by simulation results and the ones generated by centrality measures, we show that our method can rank the spreading ability of nodes more accurately than centrality measures such as degree, -shell, betweenness, closeness and local centrality. Through experiments on artificial networks generated by Barabási–Albert (BA) [26], [5] network model and Lancichinetti–Fortunato–Radicchi (LFR) network model [27], we show that our method can outperform other centrality measures in scale-free networks with different sizes and different community structure. Further, we show that our proposed method can better rank the most influential nodes than other measures considered. Moreover, we use the susceptible–infected (SI) model [25] to simulate the epidemic spreading process and show that our proposed method can better rank the spreading ability of nodes under the SI model. Finally, we examine the ability of different methods to distinguish the spreading ability of the nodes and show that our proposed method performs better.
Following parts are organized as follows. We briefly review the definition of centrality measures used for comparison in Section 2 and introduce our local structural centrality measure in Section 3. In Section 4, we present the data, the spreading model and the evaluation measure that are used to evaluate the performance of our method. The experimental results are presented in Section 5. We conclude our paper and give a discussion in Section 6.
Section snippets
Centrality measures
Consider an unweighted and undirected simple network with nodes and links. could be described by an adjacent matrix , where if node is connected with node and otherwise. We use to denote the set of neighbors within -hops from node .
The degree centrality (DC), , of node can be calculated as The computational complexity for degree centrality is .
The -shell centrality (KS) [10], , is obtained by
Our proposed local structural centrality
To begin our analysis, we first discuss the impact of the local structure of a node on its spreading ability. By local structure, we mean the structure of the nearest and next nearest neighbors of a node. As is known to us, the number of neighbors of a node can affect its spreading ability. For example, the degree centrality considers the number of the nearest neighbors and the local centrality considers the number of the nearest and the next nearest neighbors. Both of them are commonly used
Experimental setup
To evaluate the performance of our proposed centrality measure, we apply it on both artificial and real networks. The artificial networks include networks generated by the Barabási–Albert (BA) network model [26], [5] and the Lancichinetti–Fortunato–Radicchi (LFR) network model [27]. All these artificial networks are undirected unweighted and scale-free. The real networks are drawn from disparate fields, including: (i) Email: a network of e-mail interchanges between members of the University
Results
In this paper, we use relatively small values of in SIR model, namely , so that the infected percentage of the nodes remains small. When , the average infected percentage of the nodes is 0.1147 in Email, 0.0008 in Blog, 0.0057 in PGP and 0.0031 in Twitter. In the case of large values, where spreading can reach a large fraction of the nodes, the role of individual node is no longer important and spreading would cover almost all the network, independently of where it originates
Conclusion and discussions
In this paper, we propose a local structural centrality measure to rank the spreading ability of nodes in the network. The proposed centrality measure considers not only the number of nearest neighbors of a node, but also the topological connections among the neighbors. To evaluate the performance, we apply our method on both artificial and real networks and use the SIR model to simulate the spreading process. By employing the Kendall’ tau () coefficient to measure the rank correlation between
Acknowledgments
We greatly appreciate the Editor’s encouragement and the anonymous reviewer’s valuable comments and suggestions to improve this work. This work is supported by the Natural Science Foundation of China (61272240, 61103151, 71301086, 11101243), the Doctoral Fund of Ministry of Education of China (20110131110028), the Natural Science foundation of Shandong province (ZR2012FM037) and the Excellent Middle-Aged and Youth Scientists of Shandong Province (BS2012DX017, BS2012SF016).
References (45)
- et al.
A study of the spreading scheme for viral marketing based on a complex network model
Physica A
(2010) - et al.
Identifying influential nodes in complex networks
Physica A
(2012) - et al.
Identifying all-around nodes for spreading dynamics in complex networks
Physica A
(2012) - et al.
Ranking the spreading influence in complex networks
Physica A
(2013) - et al.
Identifying influential nodes in weighted networks based on evidence theory
Physica A
(2013) - et al.
Ranking spreaders by decomposing complex networks
Phys. Lett. A
(2013) Centrality in social networks conceptual clarification
Social Networks
(1978–1979)- et al.
Unified index to quantifying heterogeneity of complex networks
Physica A
(2008) - et al.
Identification of overlapping community structure in complex networks using fuzzy-means clustering
Physica A
(2007) - et al.
Infectious Diseases of Humans: Dynamics and Control
(1991)
The mathematics of infectious diseases
SIAM Rev.
Epidemic spreading in scale-free networks
Phys. Rev. Lett.
Statistical mechanics of complex networks
Rev. Modern Phys.
The small world yields the most effective information spreading
New J. Phys.
Adaptive model for recommendation of news
Europhys. Lett.
Statistical physics of social dynamics
Rev. Modern Phys.
Identification of influential spreaders in complex networks
Nat. Phys.
Identifying influential spreaders and efficiently estimating infection numbers in epidemic models: a walk counting approach
Europhys. Lett.
Leaders in social networks, the delicious case
PLoS One
Quantifying the influence of scientists and their publications: distinguishing between prestige and popularity
New J. Phys.
The centrality index of a graph
Psychometrika
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