International Journal of Modern Physics C

This paper constructs a model of the consensus formation in Internet based on the directed graph after analyzing the classical models of the social consensus formation, sets up the rules for the evolvement of opinions of agents and induces the evolving algorithm of consensus in Internet. The paper presents some key parameters such as the influence area of the mainstream media, the average influence of the mainstream media, the average self-persisting ability of agents and etc. Simulation results on a small-world networks show that the less the average self-persisting capability of the agents is, the easier the guidance of the media will be. The stronger the average influence of the main stream media is, the easier the mainstream media guides the consensus. These results reflect the formation law of the network consensus and are consistent approximately with the real circumstance.

An improved cluster dynamics model has been developed for studying the behaviors of hydrogen retention in tungsten under hydrogen ions irradiation. In addition to different types of objects, adopting up-to-date parameters and complex reaction processes, we newly introduce ion-induced and natural defects into our model. This improved model programmed in IRadMat2 could describe very well the depth distributions and the amounts of hydrogen retained in tungsten under different radiation conditions. The calculated results agree with the experimental ones much better than the previous model, especially for the depth-distribution of D retained in W, which imply that this model is applicable to the evolution of defects especially for low energy high flux ions irradiated on plasma-facing materials.

A density functional study for structural and electronic properties of Zinc Oxide (ZnO), in wurtzite, rock salt and zinc-blende phases has been performed using full potential-linearized augmented plane wave/linearized augmented plane wave plus local ideal orbital (FP-LAPW/L(APW+lo) approach as realized in WIEN2k code. To approximate exchange correlation energy and corresponding potential, a special GGA parameterized by Wu–Cohen has been implemented. Our results of lattice constants, bulk moduli as well as for internal parameter with GGA-WC are found to be more reliable. This study reveals that value of internal parameter decreases with increasing volume whereas computed electronic band structure confirms the direct band gap behavior of ZnO in B4 and B3 phases while indirect band gap behavior in B1 phase. Moreover, two fold degeneracy at the maxima of valence band for B4 and B1 phases whereas three fold for B3 is observed. A detailed comparison with experimental and other first principles studies is also made.

This study explores the community structure in spatial maritime shipping networks. As compared with air transportation networks and urban road networks, ports in spatial maritime shipping networks have smaller connections due to the physical confinement. A new divisive algorithm is proposed for detecting community structure in spatial maritime shipping networks. At each iteration for modularity optimization, the length of each edge is successively updated, instead of edge removal used in the conventional divisive method. Finally, numerical experiments based on the global maritime shipping network are carried out to account for the properties of community structure in spatial maritime shipping networks.

In this paper, we empirically investigate the statistical properties of the user correlation network in terms of their common rated objects on MovieLens, and find that it has high clustering coefficient and ultra small average distance, which is close to the fully connected network. We argue that the above characteristics come from the fact that large-degree objects build lots of fully connected subnetworks by using the node projection method. By introducing the user global similarity, measured by the product of two users' similarity vectors, we present an effective way to identify users' specific interests by weakening the mainstream interests and noise interests. Numerical results show that we are able to obtain accurate and diverse recommendations by considering the second-order correlation redundant information simultaneously, which outperforms the state-of-the-art collaborative filtering (CF) methods. This work suggests that statistical properties of the user correlation network is an important factor to improve the performances of information filtering algorithms.

In this work we present an agent-based model for the spread of tuberculosis where the individuals can be infected with either drug-susceptible or drug-resistant strains and can also receive a treatment. The dynamics of the model and the role of each one of the parameters are explained. The whole set of parameters is explored to check their importance in the numerical simulation results. The model captures the beneficial impact of the adequate treatment on the prevalence of tuberculosis. Nevertheless, depending on the treatment parameters range, it also captures the emergence of drug resistance. Drug resistance emergence is particularly likely to occur for parameter values corresponding to less efficacious treatment, as usually found in developing countries.

Within the context of agent-based Monte-Carlo simulations, we study the problem of the fluctuations of tax evasion in a community of honest citizens and tax evaders by using the version of the nonequilibrium Zaklan model proposed by Lima (2010). The studied evolutionary dynamics of tax evasion are driven by a non-equilibrium majority-vote model of M. J. Oliveira, with the objective to attempt to control the fluctuations of the tax evasion in the observed community in which citizens are localized on the nodes of the Stauffer–Hohnisch–Pittnauer networks.

A multiple look-ahead model is extended to take into account the reaction-time delay of drivers. The stability condition of this model is obtained by using the linear stability theory. Through nonlinear analysis, the Korteweg–de Vries (KdV) equation near the neutral stability line and the modified KdV (mKdV) equation near the critical point are derived. Both the analytical and simulation results demonstrate that the stabilization of traffic flow is weakened with increasing the reaction-time delay of drivers, and multiple look-ahead consideration could partially remedy this unfavorable effect.