39 research outputs found
Dynamics of clustered opinions in complex networks
A simple model for simulating tug of war game as varying the player number in
a team is discussed to identify the slow pace of fast change. This model shows
that a large number of information sources leads slow change for the system.
Also, we introduce an opinion diffusion model including the effect of a high
degree of clustering. This model shows that the de facto standard and lock-in
effect, well-known phenomena in economics and business management, can be
explained by the network clusters.Comment: 11 pages, 2 figure
The effect of spatially correlated noise on coherence resonance in a network of excitable cells
We study the effect of spatially correlated noise on coherence resonance (CR)
in a Watts-Strogatz small-world network of Fitz Hugh-Nagumo neurons, where the
noise correlation decays exponentially with distance between neurons. It is
found that CR is considerably improved just by a small fraction of long-range
connections for an intermediate coupling strength. For other coupling
strengths, an abrupt change in CR occurs following the drastic fracture of the
clustered structures in the network. Our study shows that spatially correlated
noise plays a significant role in the phenomenon of CR through enforcing the
clustering of the network.Comment: 11 pages, 4 figur
Pattern Formation in a Two-Dimensional Array of Oscillators with Phase-Shifted Coupling
We investigate the dynamics of a two-dimensional array of oscillators with
phase-shifted coupling. Each oscillator is allowed to interact with its
neighbors within a finite radius. The system exhibits various patterns
including squarelike pinwheels, (anti)spirals with phase-randomized cores, and
antiferro patterns embedded in (anti)spirals. We consider the symmetry
properties of the system to explain the observed behaviors, and estimate the
wavelengths of the patterns by linear analysis. Finally, we point out the
implications of our work for biological neural networks
Characteristics of the Korean stock market correlations
In this study, we establish a network structure of the Korean stock market,
one of the emerging markets, with its minimum spanning tree through the
correlation matrix. Base on this analysis, it is found that the Korean stock
market doesn't form the clusters of the business sectors or of the industry
categories. When the MSCI (Morgan Stanley Capital International Inc.) index is
exploited, we found that the clusters of the Korean stock market is formed.
This finding implicates that the Korean market, in this context, is
characteristically different form the mature markets.Comment: 11 pages, 3 figures, revised on June 200
Dynamics of Helping Behavior and Networks in a Small World
To investigate an effect of social interaction on the bystanders'
intervention in emergency situations a rescue model was introduced which
includes the effects of the victim's acquaintance with bystanders and those
among bystanders from a network perspective. This model reproduces the
experimental result that the helping rate (success rate in our model) tends to
decrease although the number of bystanders increases. And the interaction
among homogeneous bystanders results in the emergence of hubs in a helping
network. For more realistic consideration it is assumed that the agents are
located on a one-dimensional lattice (ring), then the randomness
is introduced: the random bystanders are randomly chosen from a whole
population and the near bystanders are chosen in the nearest order to
the victim. We find that there appears another peak of the network density in
the vicinity of and due to the cooperative and competitive
interaction between the near and random bystanders.Comment: 13 pages, 8 figure
Time-delayed Spatial Patterns in a Two-dimensional Array of Coupled Oscillators
We investigated the effect of time delays on phase configurations in a set of
two-dimensional coupled phase oscillators. Each oscillator is allowed to
interact with its neighbors located within a finite radius, which serves as a
control parameter in this study. It is found that distance-dependent
time-delays induce various patterns including traveling rolls, square-like and
rhombus-like patterns, spirals, and targets. We analyzed the stability
boundaries of the emerging patterns and briefly pointed out the possible
empirical implications of such time-delayed patterns.Comment: 5 Figure