159 research outputs found
Majority Model on a network with communities
We focus on the majority model in a topology consisting of two coupled
fully-connected networks, thereby mimicking the existence of communities in
social networks. We show that a transition takes place at a value of the
inter-connectivity parameter. Above this value, only symmetric solutions
prevail, where both communities agree with each other and reach consensus.
Below this value, in contrast, the communities can reach opposite opinions and
an asymmetric state is attained. The importance of the interface between the
sub-networks is shown.Comment: 4 page
Coevolution of Information Processing and Topology in Hierarchical Adaptive Random Boolean Networks
Random Boolean networks (RBNs) are frequently employed for modelling complex
systems driven by information processing, e.g. for gene regulatory networks
(GRNs). Here we propose a hierarchical adaptive RBN (HARBN) as a system
consisting of distinct adaptive RBNs - subnetworks - connected by a set of
permanent interlinks. Information measures and internal subnetworks topology of
HARBN coevolve and reach steady-states that are specific for a given network
structure. We investigate mean node information, mean edge information as well
as a mean node degree as functions of model parameters and demonstrate HARBN's
ability to describe complex hierarchical systems.Comment: 9 pages, 6 figure
Modelling Collective Opinion Formation by Means of Active Brownian Particles
The concept of active Brownian particles is used to model a collective
opinion formation process. It is assumed that individuals in community create a
two-component communication field that influences the change of opinions of
other persons and/or can induce their migration. The communication field is
described by a reaction-diffusion equation, the opinion change of the
individuals is given by a master equation, while the migration is described by
a set of Langevin equations, coupled by the communication field. In the
mean-field limit holding for fast communication we derive a critical population
size, above which the community separates into a majority and a minority with
opposite opinions. The existence of external support (e.g. from mass media)
changes the ratio between minority and majority, until above a critical
external support the supported subpopulation exists always as a majority.
Spatial effects lead to two critical ``social'' temperatures, between which the
community exists in a metastable state, thus fluctuations below a certain
critical wave number may result in a spatial opinion separation. The range of
metastability is particularly determined by a parameter characterizing the
individual response to the communication field. In our discussion, we draw
analogies to phase transitions in physical systems.Comment: Revised text version. Accepted for publication in European Physics
Journal B. For related work see
http://summa.physik.hu-berlin.de/~frank/active.html and
http://www.if.pw.edu.pl/~jholys
Ising model on two connected Barabasi-Albert networks
We investigate analytically the behavior of Ising model on two connected
Barabasi-Albert networks. Depending on relative ordering of both networks there
are two possible phases corresponding to parallel or antiparallel alingment of
spins in both networks. A difference between critical temperatures of both
phases disappears in the limit of vanishing inter-network coupling for
identical networks. The analytic predictions are confirmed by numerical
simulations.Comment: 6 pages including 6 figure
Opinion dynamics driven by leaders, media, viruses and worms
A model on the effects of leader, media, viruses, and worms and other agents
on the opinion of individuals is developed and utilized to simulate the
formation of consensus in society and price in market via excess between supply
and demand. Effects of some time varying drives, (harmonic and hyperbolic) are
also investigated.
Key words: Opinion; Leader; Media; Market; Buyers; Sellers; ExcessComment: 14 pages, 7 figures (14, total) Will be published in IJMP
Shock waves in one-dimensional Heisenberg ferromagnets
We use SU(2) coherent state path integral formulation with the stationary
phase approximation to investigate, both analytically and numerically, the
existence of shock waves in the one- dimensional Heisenberg ferromagnets with
anisotropic exchange interaction. As a result we show the existence of shock
waves of two types,"bright" and "dark", which can be interpreted as moving
magnetic domains.Comment: 10 pages, with 3 ps figure
Ferromagnetic fluid as a model of social impact
The paper proposes a new model of spin dynamics which can be treated as a
model of sociological coupling between individuals. Our approach takes into
account two different human features: gregariousness and individuality. We will
show how they affect a psychological distance between individuals and how the
distance changes the opinion formation in a social group. Apart from its
sociological aplications the model displays the variety of other interesting
phenomena like self-organizing ferromagnetic state or a second order phase
transition and can be studied from different points of view, e.g. as a model of
ferromagnetic fluid, complex evolving network or multiplicative random process.Comment: 8 pages, 5 figure
The critical properties of the agent-based model with environmental-economic interactions
The steady-state and nonequilibrium properties of the model of
environmental-economic interactions are studied. The interacting heterogeneous
agents are simulated on the platform of the emission dynamics of cellular
automaton. The model possess the discontinuous transition between the safe and
catastrophic ecology. Right at the critical line, the broad-scale power-law
distributions of emission rates have been identified. Their relationship to
Zipf's law and models of self-organized criticality is discussed.Comment: 12 pages, 6 figures, published in Physica
Parameters of state in the global thermodynamics of binary ideal gas mixtures in a stationary heat flow
We formulate the first law of global thermodynamics for stationary states of
the binary ideal gas mixture subjected to heat flow. We map the non-uniform
system onto the uniform one and show that the internal energy
is the function of the following parameters of
state: a non-equilibrium entropy , volume , number of particles of the
first component, , number of particles of the second component and
the renormalized degrees of freedom. The parameters ,
satisfy the relation (, where is the
fraction of component, and are the degrees of freedom for each
component respectively). Thus only 5 parameters of state describe the
non-equilibrium state of the binary mixture in the heat flow. We calculate the
non-equilibrium entropy and new thermodynamic parameters of state
explicitly. The latter are responsible for heat generation due
to the concentration gradients. The theory reduces to equilibrium
thermodynamics, when the heat flux goes to zero. As in equilibrium
thermodynamics, the steady-state fundamental equation also leads to the
thermodynamic Maxwell relations for measurable steady-state properties.Comment: 8 pages, 1 figur
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