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1.
Qian Li Lidia A. Braunstein Huijuan Wang Jia Shao H. Eugene Stanley Shlomo Havlin 《Journal of statistical physics》2013,151(1-2):92-112
Social dynamic opinion models have been widely studied to understand how interactions among individuals cause opinions to evolve. Most opinion models that utilize spin interaction models usually produce a consensus steady state in which only one opinion exists. Because in reality different opinions usually coexist, we focus on non-consensus opinion models in which above a certain threshold two opinions coexist in a stable relationship. We revisit and extend the non-consensus opinion (NCO) model introduced by Shao et al. (Phys. Rev. Lett. 103:01870, 2009). The NCO model in random networks displays a second order phase transition that belongs to regular mean field percolation and is characterized by the appearance (above a certain threshold) of a large spanning cluster of the minority opinion. We generalize the NCO model by adding a weight factor W to each individual’s original opinion when determining their future opinion (NCOW model). We find that as W increases the minority opinion holders tend to form stable clusters with a smaller initial minority fraction than in the NCO model. We also revisit another non-consensus opinion model based on the NCO model, the inflexible contrarian opinion (ICO) model (Li et al. in Phys. Rev. E 84:066101, 2011), which introduces inflexible contrarians to model the competition between two opinions in a steady state. Inflexible contrarians are individuals that never change their original opinion but may influence the opinions of others. To place the inflexible contrarians in the ICO model we use two different strategies, random placement and one in which high-degree nodes are targeted. The inflexible contrarians effectively decrease the size of the largest rival-opinion cluster in both strategies, but the effect is more pronounced under the targeted method. All of the above models have previously been explored in terms of a single network, but human communities are usually interconnected, not isolated. Because opinions propagate not only within single networks but also between networks, and because the rules of opinion formation within a network may differ from those between networks, we study here the opinion dynamics in coupled networks. Each network represents a social group or community and the interdependent links joining individuals from different networks may be social ties that are unusually strong, e.g., married couples. We apply the non-consensus opinion (NCO) rule on each individual network and the global majority rule on interdependent pairs such that two interdependent agents with different opinions will, due to the influence of mass media, follow the majority opinion of the entire population. The opinion interactions within each network and the interdependent links across networks interlace periodically until a steady state is reached. We find that the interdependent links effectively force the system from a second order phase transition, which is characteristic of the NCO model on a single network, to a hybrid phase transition, i.e., a mix of second-order and abrupt jump-like transitions that ultimately becomes, as we increase the percentage of interdependent agents, a pure abrupt transition. We conclude that for the NCO model on coupled networks, interactions through interdependent links could push the non-consensus opinion model to a consensus opinion model, which mimics the reality that increased mass communication causes people to hold opinions that are increasingly similar. We also find that the effect of interdependent links is more pronounced in interdependent scale free networks than in interdependent Erd?s Rényi networks. 相似文献
2.
An opinion evolution model without “bounded confidence” is proposed in this paper. Computer simulation shows that our model
can figure out the breakage of the coexistence of majority and minority after a period’s evolution. With further analysis,
our model shows that, without the influence of the external field, the opinions will finally die out to a limited small value
no matter what the initial condition of the system is. On the other hand, we simulate the evolution of the opinions under
the influence of an external field, and get some meaningful and instructional results. 相似文献
3.
M. Porfiri E. M. Bollt D. J. Stilwell 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(4):481-486
Opinion compromise models can give insight into how groups of individuals may either come to form
consensus or clusters of opinion groups, corresponding to parties. We consider models where randomly
selected individuals interact pairwise. If the opinions of the interacting agents are not within a certain confidence
threshold, the agents retain their own point of view. Otherwise, they constructively dialogue and smooth their
opinions. Persuasible agents are inclined to compromise with interacting individuals. Stubborn individuals slightly
modify their opinion during the interaction. Collective states for persuasible societies include extremist minorities,
which instead decline in stubborn societies. We derive a mean field approximation for the compromise model in stubborn
populations. Bifurcation and clustering analysis of this model compares favorably with Monte Carlo analysis found in
the literature. 相似文献
4.
V.A. Stephanovich 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,18(1):17-21
We predict the existence of a Griffiths phase in dielectrics with a concentrational crossover between dipole glass (electric
analog of spin glass) and ferroelectricity. Particular representatives of the above substances are KTaO3:Li, Nb, Na, or relaxor ferroelectrics like Pb1–xLaxZr0.65Ti0.35O3. Since this phase exists above the ferroelectric phase-transition temperature (but below that temperature for ordered substances),
we call it a “para-glass phase”. We assert that the difference between paraelectric and para-glass phases in the above substances
is the existence of clusters (inherent to the “ordinary” Griffiths phase of Ising magnets) of correlated dipoles. We show
that randomness plays a decisive role in the Griffiths (para-glass) phase formation: this phase does not exist in a mean field
approximation. To investigate the Griffiths phase properties, we calculate the density of Yang-Lee (YL) zeros in the partition
function and find that it has “tails” inherent to the Griffiths phase in the above temperature interval. We perform calculations
on the basis of our self-consistent equation for the long-range order parameter in an external electric field. This equation
has been derived in the framework of the random field theory. The latter automatically incorporates both short-range (due
to indirect interaction via transverse optical phonons of the host lattice) and long-range (ordinary dipole-dipole) interactions between impurity dipoles,
so that the problem of long-range interaction considerations does not appear in it.
Received 17 May 2000 相似文献
5.
S. Galam B. Chopard A. Masselot M. Droz 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,4(4):529-531
A simple cellular automata model for a two-group war over the same “territory” is presented. It is shown that a qualitative
advantage is not enough for a minority to win. A spatial organization as well a definite degree of aggressiveness are instrumental
to overcome a less fitted majority. The model applies to a large spectrum of competing groups: smoker-non smoker war, epidemic
spreading, opinion formation, competition for industrial standards and species evolution. In the last case, it provides a
new explanation for punctuated equilibria.
Received: 21 April 1998 / Revised and Accepted: 22 April 1998 相似文献
6.
P. P. Li P. M. Hui 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(3):371-376
The dynamics of opinion formation based on a majority
rule model is studied in a network with the social hierarchical
structure as one of its limits. The exit probability is found to
change sensitively with the number of nodes in the system, but not
with the parameter of homophyly characterizing the network
structure. The consensus time is found to be a result of
non-trivial interplay between the network structure characterized
by the parameter of homophyly and the initial bias in opinion. For
unbiased initial opinion, a common consensus is easier to be
reached in a random network than a highly structured hierarchical
network and it follows the behavior of the length of shortest
paths. For biased initial opinion, a common consensus is easier
to be reached in a hierarchical network, as the local majority
opinion of the groups may take on the biased opinions and hence be
the same. 相似文献
7.
Our agent-based model of opinion dynamics concerns the current vast divisions in modern societies. It examines the process of social polarization, understood here as the partition of a community into two opposing groups with contradictory opinions. Our goal is to measure how mutual animosities between parties may lead to their radicalization. We apply a double-clique topology with both positive and negative ties to the model of binary opinions. Individuals are subject to social pressure; they conform to the opinions of their own clique (positive links) and oppose those from the other one (negative links). There is also a chance of acting independently, which alters the system’s behavior in various ways, depending on its magnitude. The results, obtained with both Monte-Carlo simulations and the mean-field approach, lead to two main conclusions: in such a system, there exists a critical quantity of negative relations that are needed for polarization to occur, and (rather surprisingly) independent actions actually support the process, unless their frequency is too high, in which case the system falls into total disorder. 相似文献
8.
In this paper, we focus on the effect of a network’s structure on the process of opinion formation. Emphasis is placed on the minority’s opinion evolution in a community structured network, where the majority rule is applied to govern the evolution. A model is developed for theoretical analysis using the mean field method. In this model, the connections are dense in the community, but sparse outside. A bifurcation diagram can thus be constructed, which is also verified through experimental study. The phase transition in the evolution is also investigated. In addition, a further investigation shows that a larger group size would bring more advantage to the minority. 相似文献
9.
The dynamics of spreading of the minority opinion in public debates (a reform proposal, a behavior change, a military retaliation)
is studied using a diffusion reaction model. People move by discrete step on a landscape of random geometry shaped by social
life (offices, houses, bars, and restaurants). A perfect world is considered with no advantage to the minority. A one person-one
argument principle is applied to determine locally individual mind changes. In case of equality, a collective doubt is evoked
which in turn favors the Status Quo. Starting from a large in favor of the proposal initial majority, repeated random size
local discussions are found to drive the majority reversal along the minority hostile view. Total opinion refusal is completed
within few days. Recent national collective issues are revisited. The model may apply to rumor and fear propagation.
Received 23 January 2002 相似文献
10.
A model for ripple instabilities in granular media 总被引:1,自引:0,他引:1
O. Terzidis P. Claudin J.-P. Bouchaud 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,5(2):245-249
We extend the model of surface granular flow proposed in [#!bcre!#] to account for the effect of an external `wind', which
acts as to dislodge particles from the static bed, such that a stationary state of flowing grains is reached. We discuss in
detail how this mechanism can be described in a phenomenological way, and show that a flat bed is linearly unstable against
ripple formation in a certain region of parameter space. We focus in particular on the (realistic) case where the migration
velocity of the instability is much smaller than the grains' velocity. In this limit, the full dispersion relation can be
established. We relate the critical wave vector to the mean hopping length and to the ratio of the flight time to the `stick'
time. We provide an intuitive interpretation of the instability.
Received: 30 January 1998 / Revised: 12 May 1998 / Accepted: 8 June 1998 相似文献
11.
Barbara Pabjan 《Physica A》2008,387(24):6183-6189
A simple model describing the dynamics of opinion forming in a two-party society is presented. Using a Monte Carlo simulation, we show what is the role played by the mobility of the electorate and the size of the groups within which opinions are exchanged. Each individual is characterized by its opinion and its susceptibility to the influence of others. We show what is the effect for a party to have a small percentage of supporters who will never change their mind. We determine when a party having at the beginning a smaller number of supporters, could nevertheless win democratic elections. The influence of an external random field (media) is also discussed. 相似文献
12.
M. Pineda R. Toral E. Hernández-García 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,62(1):109-117
We study the effects of diffusing opinions on the Deffuant et al. model for continuous
opinion dynamics. Individuals are given the opportunity to change their opinion, with a
given probability, to a randomly selected opinion inside an interval centered around the
present opinion. We show that diffusion induces an order-disorder transition. In the
disordered state the opinion distribution tends to be uniform, while for the ordered state
a set of well defined opinion clusters are formed, although with some opinion spread
inside them. If the diffusion jumps are not large, clusters coalesce, so that weak
diffusion favors opinion consensus. A master equation for the process described above is
presented. We find that the master equation and the Monte Carlo simulations do not always
agree due to finite-size induced fluctuations. Using a linear stability analysis we can
derive approximate conditions for the transition between opinion clusters and the
disordered state. The linear stability analysis is compared with Monte Carlo simulations.
Novel interesting phenomena are analyzed. 相似文献
13.
A basic characteristic of most opinion models is that people tend to agree or compromise in the opinion interaction, which could be hopefully described by cooperative games in the evolutionary game theory framework. This paper presents game theory methods to model the formation of binary opinions: cooperative games are proposed to model the interaction rules of general people who tend to find an agreement; minority games are proposed to model the behaviors of contrarians; opinion preference is considered by varying the payoff values. The Majority Voter model could be restored from the proposed games. The game theory models show evolutionary results similar to traditional opinion models. Specially, the evolution of opinions with consideration of contrarians is in accordance with the Galam model. Furthermore, influences of evolving rule, network topology and initial distribution of opinions are studied through numerical simulations. Discussions about methods to promote or hinder the consensus state at the best equilibrium point are given. 相似文献
14.
Thermal convection in a rotating layer of a magnetic fluid 总被引:1,自引:0,他引:1
G.K. Auernhammer H.R. Brand 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,16(1):157-168
We consider Brownian particles with the ability to take up energy from the environment, to store it in an internal depot,
and to convert internal energy into kinetic energy of motion. Provided a supercritical supply of energy, these particles are
able to move in a “high velocity” or active mode, which allows them to move also against the gradient of an external potential.
We investigate the critical energetic conditions of this self-driven motion for the case of a linear potential and a ratchet
potential. In the latter case, we are able to find two different critical conversion rates for the internal energy, which
describe the onset of a directed net current into the two different directions. The results of computer simulations are confirmed
by analytical expressions for the critical parameters and the average velocity of the net current. Further, we investigate
the influence of the asymmetry of the ratchet potential on the net current and estimate a critical value for the asymmetry
in order to obtain a positive or negative net current.
Received 20 September 1999 相似文献
15.
R. Metzler 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,19(2):249-258
A generalised random walk scheme for random walks in an arbitrary external potential field is investigated. From this concept
which accounts for the symmetry breaking of homogeneity through the external field, a generalised master equation is constructed.
For long-tailed transfer distance or waiting time distributions we show that this generalised master equation is the genesis
of apparently different fractional Fokker-Planck equations discussed in literature. On this basis, we introduce a generalisation
of the Kramers-Moyal expansion for broad jump length distributions that combines multiples of both ordinary and fractional
spatial derivatives. However, it is shown that the nature of the drift term is not changed through the existence of anomalous
transport statistics, and thus to first order, an external potential Φ(x) feeds back on the probability density function W through the classical term ∝/
x
(x)W(x, t), i.e., even for Lévy flights, there exists a linear infinitesimal generator that accounts for the response to an external field.
Received 30 June 2000 and Received in final form 12 November 2000 相似文献
16.
Julien M. Hendrickx 《Physica A》2008,387(21):5255-5262
Krause’s model of opinion dynamics has recently been the subject of several studies, partly because it is one of the simplest multi-agent systems involving position-dependent changing topologies. In this model, agents have an opinion represented by a real number and they update it by averaging those agent opinions distant from their opinion by less than a certain interaction radius. Some results obtained on this model rely on the fact that the opinion orders remain unchanged under iteration, a property that is consistent with the intuition in models with simultaneous updating on a fully connected communication topology.Several variations of this model have been proposed. We show that some natural variations are not order preserving and therefore cause potential problems with the theoretical analysis and the consistence with the intuition. We consider a generic version of Krause’s model parameterized by an “influence function” that encapsulates most of the variations proposed in the literature. We then derive a necessary and sufficient condition on this function for the opinion order to be preserved. 相似文献
17.
M. Kuperman D. Zanette 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,26(3):387-391
We analyze the phenomenon of stochastic resonance in an Ising-like system on a small-world network. The system, which is subject
to the combined action of noise and an external modulation, can be interpreted as a stylized model of opinion formation by
imitation under the effects of a “fashion wave”. Both the amplitude threshold for the detection of the external modulation
and the width of the stochastic-resonance peak show considerable variation as the randomness of the underlying small-world
network is changed.
Received 19 December 2001 相似文献
18.
A. Pluchino V. Latora A. Rapisarda 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):169-176
We discuss two models of opinion dynamics. We first present a brief review of
the Hegselmann and Krause (HK) compromise model in two dimensions,
showing that it is possible to simulate the dynamics
in the limit of an infinite number of agents by solving numerically a rate equation for
a continuum distribution of opinions. Then, we discuss the Opinion Changing Rate (OCR) model,
which allows to study under which conditions a group of agents with a
different natural tendency (rate) to change opinion can find the
agreement. In the context of the this model, consensus is viewed as a synchronization
process. 相似文献
19.
Alina Sîrbu Vittorio Loreto Vito D. P. Servedio Francesca Tria 《Journal of statistical physics》2013,151(1-2):218-237
Opinion dynamics concerns social processes through which populations or groups of individuals agree or disagree on specific issues. As such, modelling opinion dynamics represents an important research area that has been progressively acquiring relevance in many different domains. Existing approaches have mostly represented opinions through discrete binary or continuous variables by exploring a whole panoply of cases: e.g. independence, noise, external effects, multiple issues. In most of these cases the crucial ingredient is an attractive dynamics through which similar or similar enough agents get closer. Only rarely the possibility of explicit disagreement has been taken into account (i.e., the possibility for a repulsive interaction among individuals’ opinions), and mostly for discrete or 1-dimensional opinions, through the introduction of additional model parameters. Here we introduce a new model of opinion formation, which focuses on the interplay between the possibility of explicit disagreement, modulated in a self-consistent way by the existing opinions’ overlaps between the interacting individuals, and the effect of external information on the system. Opinions are modelled as a vector of continuous variables related to multiple possible choices for an issue. Information can be modulated to account for promoting multiple possible choices. Numerical results show that extreme information results in segregation and has a limited effect on the population, while milder messages have better success and a cohesion effect. Additionally, the initial condition plays an important role, with the population forming one or multiple clusters based on the initial average similarity between individuals, with a transition point depending on the number of opinion choices. 相似文献
20.
M. Wołoszyn D. Stauffer K. Kułakowski 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(3):331-335
We investigate the network model of community by Watts, Dodds and Newman (D.J. Watts et al., Science 296, 1302 (2002)) as a hierarchy of groups, each of 5 individuals. A homophily parameter
α controls the probability proportional to exp (-αx) of selection of neighbours
against distance x. The network nodes are endowed with spin-like variables si = ± 1,
with Ising interaction J > 0. The Glauber dynamics is used to investigate the
order-disorder transition. The transition temperature Tc is close to 3.8 for
α < 0.0 and it falls down to zero above this value. The result provides a mathematical
illustration of the social ability to a collective action via weak ties, as discussed
by Granovetter in 1973. 相似文献