In: Physica A: Statistical Mechanics and its Applications, 2011, vol. 390, no. 12, p. 2395-2400
In this paper, we study the statistical properties of bookmarking behaviors in Delicious.com. We find that the inter-event time (τ) distributions of bookmarking decay in a power-like manner as τ increases at both individual and population levels. Remarkably, we observe a significant change in the exponent when the inter-event time increases from the intra-day range to the inter-day range. In...
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In: International Journal of Modern Physics C, 2009, vol. 20, no. 2, p. 285-293
In this paper, we propose a spreading activation approach for collaborative filtering (SA-CF). By using the opinion spreading process, the similarity between any users can be obtained. The algorithm has remarkably higher accuracy than the standard collaborative filtering using the Pearson correlation. Furthermore, we introduce a free parameter β to regulate the contributions of objects to...
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In: Physical Review E, 2009, vol. 80, no. 1, p. 017101
n this Brief Report, we propose an index of user similarity, namely, the transferring similarity, which involves all high-order similarities between users. Accordingly, we design a modified collaborative filtering algorithm, which provides remarkably higher accurate predictions than the standard collaborative filtering. More interestingly, we find that the algorithmic performance will approach...
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In: Chinese Physics Letters, 2010, vol. 27, no. 4, p. 048701
Empirical observations indicate that the interevent time distribution of human actions exhibits heavy-tailed features. The queuing model based on task priorities is to some extent successful in explaining the origin of such heavy tails, however, it cannot explain all the temporal statistics of human behavior especially for the daily entertainments. We propose an interest-driven model, which can...
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In: New Journal of Physics, 2008, vol. 10, p. 073010
Increasing recent empirical evidence indicates the extensive existence of heavy tails in the inter-event time distributions of various human behaviors. Based on the queuing theory, the Barabási model and its variations suggest the highest-priority-first protocol to be a potential origin of those heavy tails. However, some human activity patterns, also displaying heavy-tailed temporal statistics,...
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In: The European Physical Journal B, 2008, vol. 65, no. 2, p. 251-255
We investigate the self-affirmation effect on formation of public opinion in a directed small-world social network. The system presents a non-equilibrium phase transition from a consensus state to a disordered state with coexistence of opinions. The dynamical behaviors are very sensitive to the density of long-range-directed interactions and the strength of self-affirmation. When the...
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In: Chinese Physics Letters, 2008, vol. 25, no. 2, p. 773-775
A continuum opinion dynamic model is presented based on two rules. The first one considers the mobilities of the individuals, the second one supposes that the individuals update their opinions independently. The results of the model indicate that the bounded confidence ∈c, separating consensus and incoherent states, of a scale-free network is much smaller than the one of a...
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In: Physical Review E, 2008, vol. 78, no. 6, p. 066109
Contact processes on complex networks are a recent subject of study in nonequilibrium statistical physics and they are also important to applied fields such as epidemiology and computer and communication networks. A basic issue concerns finding an optimal strategy for spreading. We provide a universal strategy that, when a basic quantity in the contact process dynamics, the contact probability...
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In: Physical Review E, 2009, vol. 79, no. 5, p. 052102
We study a system of self-propelled agents with the restricted vision. The field of vision of each agent is only a sector of disk bounded by two radii and the included arc. The inclination of these two radii is characterized by the view angle. The consideration of restricted vision is closer to the reality because natural swarms usually do not have a panoramic view. Interestingly, we find that...
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In: Physica A: Statistical Mechanics and its Applications, 2009, vol. 388, no. 4, p. 462-468
In this paper, we propose a novel method to compute the similarity between congeneric nodes in bipartite networks. Different from the standard cosine similarity, we take into account the influence of a node’s degree. Substituting this new definition of similarity for the standard cosine similarity, we propose a modified collaborative filtering (MCF). Based on a benchmark database, we...
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