In: Physical Review E, 2009, vol. 79, no. 2, p. 026113
In recent years, many efforts have been addressed on collision avoidance of collectively moving agents. In this paper, we propose a modified version of the Vicsek model with adaptive speed, which can guarantee the absence of collisions. However, this strategy leads to an aggregated state with slowly moving agents. We therefore further add a certain repulsion, which results in both faster...
|
In: International Journal of Modern Physics C, 2008, vol. 19, no. 9, p. 1359 - 1366
In this paper, we numerically investigate the structural characteristics that affect the synchronizability of coupled identical oscillators on scale-free networks. By using the edge-exchange method, we can change the network structure with degree sequence fixed. An optimal algorithm, namely Tabu Search, is applied, respectively, to enhance and weaken the synchronizability. The numerical results...
|
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...
|
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...
|
In: Physical Review E, 2007, vol. 76, p. 061903
In this paper, we investigate the dynamical properties of electroencephalogram (EEG) signals of humans in sleep. By using a modified random walk method, we demonstrate that scale-invariance is embedded in EEG signals after a detrending procedure is applied. Furthermore, we study the dynamical evolution of the probability density function (PDF) of the detrended EEG signals by nonextensive...
|
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,...
|
In: Physical Review E, 2007, vol. 76, p. 057103
In this Brief Report, we study the synchronization of growing scale-free networks. An asymmetrical age-based coupling method is proposed with only one free parameter α. Although the coupling matrix is asymmetric, our coupling method could guarantee that all the eigenvalues are non-negative reals. The eigenratio R will approach 1 in the large limit of α
|
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...
|
In: Physical Review E, 2007, vol. 76, no. 3, p. 037102
The community structure and motif-modular-network hierarchy are of great importance for understanding the relationship between structures and functions. We investigate the distribution of clique degrees, which are an extension of degree and can be used to measure the density of cliques in networks. Empirical studies indicate the extensive existence of power-law clique-degree distributions in...
|
In: Chinese Physics Letters, 2007, vol. 24, no. 10, p. 3002
We investigate a set of complex heart rate time series from healthy human in different behaviour states with the detrended fluctuation analysis and diffusion entropy (DE) method. It is proposed that the scaling properties are influenced by behaviour states. The memory detected by DE exhibits an approximately same pattern after a detrending procedure. Both of them demonstrate the long-range strong...
|