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1.
L. H. Shang X. Li X. F. Wang 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(3):369-373
We investigate the evolution of cooperative behaviors of small-world networking agents in a snowdrift game mode, where two
agents (nodes) are connected with probability depending on their spatial Euclidean lattice distance in the power-law form
controlled by an exponent α.
Extensive numerical simulations indicate that the game dynamics crucially depends on the spatial topological structure of
underlying networks with different values of the exponent α. Especially, in the distance-independent case of α=0, the small-world
connectivity
pattern contributes to an enhancement of cooperation compared with that in
regular lattices, even for the case of having a high cost-to-benefit ratio r. However, with the increment of α>0, when r≥0.4,
the spatial distance-dependent small-world (SDSW) structure tends to inhibit the evolution of cooperation in the snowdrift
game. 相似文献
2.
J. F. Fontanari 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(1):127-130
The hypothesis that meanings originate from discrimination tasks, in which an individual attempts to categorize N objects
using a set of M sensory channels, is examined within
a quantitative statistical perspective. Failure
in discrimination triggers the refinement of a randomly-chosen sensory channel, starting thus an ongoing process,
termed discrimination game, that ends only when all objects are
differentiated. We show that the expected number of trials of a discrimination game diverges
in the case of a single channel and scales with the power N2/M for M ≥2. 相似文献
3.
A. Szolnoki M. Perc 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,67(3):337-344
We study the evolution of cooperation in structured populations within popular models of social dilemmas, whereby simple coevolutionary
rules are introduced that may enhance players abilities to enforce their strategy on the opponent. Coevolution thus here refers
to an evolutionary process affecting the teaching activity of players that accompanies the evolution of their strategies.
Particularly, we increase the teaching activity of a player after it has successfully reproduced, yet we do so depending on
the disseminated strategy. We separately consider coevolution affecting either only the cooperators or only the defectors,
and show that both options promote cooperation irrespective of the applied game. Opposite to intuitive reasoning, however,
we reveal that the coevolutionary promotion of players spreading defection is, in the long run, more beneficial for cooperation
than the likewise promotion of cooperators. We explain the contradictive impact of the two considered coevolutionary rules
by examining the differences between resulting heterogeneities that segregate participating players, and furthermore, demonstrate
that the influential individuals completely determine the final outcome of the games. Our findings are immune to changes defining
the type of considered social dilemmas and highlight that the heterogeneity of players, resulting in a positive feedback mechanism,
is a fundamental property promoting cooperation in groups of selfish individuals. 相似文献
4.
H. Lin C.-X. Wu 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(4):543-547
The congestion transition triggered by multiple walkers
walking along the shortest path on complex networks is numerically
investigated. These networks are composed of nodes that have a
finite capacity in analogy to the buffer memory of a computer. It is
found that a transition from free-flow phase to congestion phase
occurs at a critical walker density fc, which varies for
complex networks with different topological structures. The dynamic
pictures of congestion for networks with different topological
structures show that congestion on scale-free networks is a
percolation process of congestion clusters, while the dynamics of
congestion transition on non-scale-free networks is mainly a process
of nucleation. 相似文献
5.
E. P. Borges D. O. Cajueiro R. F.S. Andrade 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,58(4):469-474
The objective of this study is to design a procedure to
characterize chaotic dynamical systems, in which they are
mapped onto a complex network. The nodes represent the regions of space
visited by the system, while the edges represent the transitions between
these regions. Parameters developed to quantify the properties of complex
networks, including those related to higher order neighbourhoods, are used
in the analysis. The methodology is tested on the logistic map, focusing
on the onset of chaos and chaotic regimes. The corresponding networks were
found to have distinct features that are associated with the particular
type of dynamics that generated them. 相似文献
6.
R. F.S. Andrade J. G.V. Miranda S. T.R. Pinho T. P. Lobão 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(2):247-256
A concept of higher order neighborhood in complex networks,
introduced previously [Phys. Rev. E 73, 046101 (2006)], is systematically
explored to investigate larger scale structures in complex networks. The
basic idea is to consider each higher order neighborhood as a network in
itself, represented by a corresponding adjacency matrix, and to settle a
plenty of new parameters in order to obtain a best characterization of the
whole network. Usual network indices are then used to evaluate the
properties of each neighborhood. The identification of high order
neighborhoods is also regarded as intermediary step towards the evaluation
of global network properties, like the diameter, average shortest path
between node, and network fractal dimension. Results for a large number of
typical networks are presented and discussed. 相似文献
7.
G. Ghoshal M. E.J. Newman 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,58(2):175-184
We consider distributed networks, such as peer-to-peer networks, whose
structure can be manipulated by adjusting the rules by which vertices
enter and leave the network. We focus in particular on degree
distributions and show that, with some mild constraints, it is possible
by a suitable choice of rules to arrange for the network to have any
degree distribution we desire. We also describe a mechanism based on
biased random walks by which appropriate rules could be implemented in
practice. As an example application, we describe and simulate the
construction of a peer-to-peer network optimized to minimize search times
and bandwidth requirements. 相似文献
8.
C.-L. Tang W.-X. Wang X. Wu B.-H. Wang 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,53(3):411-415
We study effects of average degree on cooperation in
the networked prisoner's dilemma game. Typical structures are
considered, including random networks, small-world networks and
scale-free networks. Simulation results show that the average
degree plays a universal role in cooperation occurring on all
these networks, that is the density of cooperators peaks at some
specific values of the average degree. Moreover, we investigated
the average payoff of players through numerical simulations
together with theoretical predictions and found that simulation
results agree with the predictions. Our work may be helpful in
understanding network effects on the evolutionary games. 相似文献
9.
This paper investigates the evolutionary prisoner’s dilemma on weighted scale-free networks. The weighted networks are generated by adopting Barabási-Albert scale-free network and assigning link weight with wij=(ki×kj)β. Simulation results show that the cooperation frequency has a strong dependence on β. The value of β which is associated with the maximal cooperation frequency has been sought out. Moreover, Gini coefficient and Pareto exponent of the system’s wealth distribution are investigated. The inequality of wealth distribution is minimized at β≈−1. 相似文献
10.
We study the evolutionary Prisoner's dilemma game on scale-free networks, focusing on the influence of different initial distributions for cooperators and defectors on the evolution of cooperation. To address this issue, we consider three types of initial distributions for defectors: uniform distribution at random, occupying the most connected nodes, and occupying the lowest-degree nodes, respectively. It is shown that initial configurations for defectors can crucially influence the cooperation level and the evolution speed of cooperation. Interestingly, the situation where defectors initially occupy the lowest-degree vertices can exhibit the most robust cooperation, compared with two other distributions. That is, the cooperation level is least affected by the initial percentage of defectors. Moreover, in this situation, the whole system evolves fastest to the prevalent cooperation. Besides, we obtain the critical values of initial frequency of defectors above which the extinction of cooperators occurs for the respective initial distributions. Our results might be helpful in explaining the maintenance of high cooperation in scale-free networks. 相似文献
11.
Z.-G. Huang X.-J. Xu Z.-X. Wu Y.-H. Wang 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(4):549-553
We carry out comparative studies of random walks on deterministic
Apollonian networks (DANs) and random Apollonian networks (RANs).
We perform computer simulations for the mean first-passage time,
the average return time, the mean-square displacement, and the
network coverage for the unrestricted random walk. The diffusions
both on DANs and RANs are proved to be sublinear. The effects of
the network structure on the dynamics and the search efficiencies
of walks with various strategies are also discussed. Contrary to
intuition, it is shown that the self-avoiding random walk, which
has been verified as an optimal local search strategy in networks,
is not the best strategy for the DANs in the large size limit. 相似文献
12.
The backbone of a city 总被引:1,自引:0,他引:1
S. Scellato A. Cardillo V. Latora S. Porta 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):221-225
Recent studies have revealed the importance of centrality measures
to analyze various spatial factors affecting human life in cities.
Here we show how it is possible to extract the backbone of a city
by deriving spanning trees based on edge betweenness and edge
information.
By using as sample cases the cities of Bologna and San Francisco,
we show how the obtained trees are radically different from those
based on edge lengths, and allow an extended comprehension of
the “skeleton” of most important routes that so much affects
pedestrian/vehicular flows, retail commerce vitality, land-use
separation, urban crime and collective dynamical behaviours. 相似文献
13.
Jiale Chen 《Physica A》2009,388(6):945-952
The system performance in an evolutionary minority game with imitation on small-world networks is studied. Numerical results show that system performance positively correlates with the clustering coefficients. The domain structure of the agents’ strategies can be used to give a qualitative explanation for it. We also find that the time series of the reduced variance σ2/N could have a phasic evolution from a metastable state (two crowds are formed but the distribution of their probabilities does not peak at p≈0 and p≈1) to a steadystate (the two crowds evolve into a crowd and an anticrowd with the distribution of their probabilities peaking at p≈0 and p≈1). 相似文献
14.
Eleni Arapaki 《Physica A》2009,388(13):2757-2761
We study the spatial prisoner’s dilemma game where the players are located on the nodes of a random scale-free network. The prisoner’s dilemma game is a powerful tool and has been used for the study of mutual trust and cooperation among individuals in structured populations. We vary the structure of the network and the payoff values for the game, and show that the specific conditions can greatly influence the outcome of the game. A variety of behaviors are reproduced and the percentage of cooperating agents fluctuates significantly, even in the absence of irrational behavior. For example, the steady state of the game may be a configuration where either cooperators or defectors dominate, while in many cases the solution fluctuates between these two limiting behaviors. 相似文献
15.
E. A. Leicht G. Clarkson K. Shedden M. E.J. Newman 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,59(1):75-83
In this paper we examine a number of methods for probing and
understanding the large-scale structure of networks that evolve over
time. We focus in particular on citation networks, networks of
references between documents such as papers, patents, or court cases. We
describe three different methods of analysis, one based on an
expectation-maximization algorithm, one based on modularity optimization,
and one based on eigenvector centrality. Using the network of citations
between opinions of the United States Supreme Court as an example, we
demonstrate how each of these methods can reveal significant structural
divisions in the network and how, ultimately, the combination of all
three can help us develop a coherent overall picture of the network's
shape. 相似文献
16.
Zhongzhi Zhang Shuigeng Zhou Lichao Chen 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,58(3):337-344
We present a family of scale-free network model consisting
of cliques, which is established by a simple recursive algorithm. We
investigate the networks both analytically and numerically. The
obtained analytical solutions show that the networks follow a
power-law degree distribution, with degree exponent continuously
tuned between 2 and 3. The exact expression of clustering
coefficient is also provided for the networks. Furthermore, the
investigation of the average path length reveals that the networks
possess small-world feature. Interestingly, we find that a special
case of our model can be mapped into the Yule process. 相似文献
17.
The $-game 总被引:1,自引:0,他引:1
J. Vitting Andersen D. Sornette 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(1):141-145
We propose a payoff function extending Minority Games (MG) that captures the competition between agents to make money. In
contrast with previous MG, the best strategies are not always targeting the minority but are shifting opportunistically between
the minority and the majority. The emergent properties of the price dynamics and of the wealth of agents are strikingly different
from those found in MG. As the memory of agents is increased, we find a phase transition between a self-sustained speculative
phase in which a “stubborn majority” of agents effectively collaborate to arbitrage a market-maker for their mutual benefit
and a phase where the market-maker always arbitrages the agents. A subset of agents exhibit a sustained non-equilibrium risk-return
profile.
Received 5 June 2002 / Received in final form 21 November 2002 Published online 27 January 2003
RID="a"
ID="a"e-mail: sornette@unice.fr
RID="b"
ID="b"CNRS UMR7536
RID="c"
ID="c"CNRS UMR6622 相似文献
18.
We study the time evolution of cooperation in a recently proposed N-person evolutionary snowdrift game, by focusing on the details of the evolutionary dynamics. It is found that the analytic solution for the equilibrium fraction of cooperators as given previously by the replicator dynamics stems from a balance between the terms: the cost to contribute to a common task and the risk in refusing to participate in a common task. Analytic expressions for these two terms are given, and their magnitudes are studied over the whole range of parameter space. Away from equilibrium, it is the imbalance between these terms that drives the system to equilibrium. A continuous time first-order differential equation for the degree of cooperation is derived, for arbitrary interacting group size N and cost-to-benefit ratio. Analytic solutions to the time evolution of cooperation for the cases of N=2 and N=3 are obtained, with results in good agreement with those obtained by numerical simulations. For arbitrary N, numerical solutions to the equation give the time evolution of cooperation, with the long time limit giving the equilibrium fraction of cooperators. 相似文献
19.
Luciano da Fontoura Costa Osvaldo N. Oliveira Jr. Gonzalo Travieso Francisco Aparecido Rodrigues Paulino Ribeiro Villas Boas Lucas Antiqueira 《物理学进展》2013,62(3):329-412
The success of new scientific areas can be assessed by their potential in contributing to new theoretical approaches and in applications to real-world problems. Complex networks have fared extremely well in both of these aspects, with their sound theoretical basis being developed over the years and with a variety of applications. In this survey, we analyze the applications of complex networks to real-world problems and data, with emphasis in representation, analysis and modeling. A diversity of phenomena are surveyed, which may be classified into no less than 11 areas, providing a clear indication of the impact of the field of complex networks. 相似文献
20.
This paper studies the evolutionary ultimatum game on networks when agents have incomplete information about the strategies of their neighborhood agents. Our model assumes that agents may initially display low fairness behavior, and therefore, may have to learn and develop their own strategies in this unknown environment. The Genetic Algorithm Learning Classifier System (GALCS) is used in the model as the agent strategy learning rule. Aside from the Watts-Strogatz (WS) small-world network and its variations, the present paper also extends the spatial ultimatum game to the Barabási-Albert (BA) scale-free network. Simulation results show that the fairness level achieved is lower than in situations where agents have complete information about other agents’ strategies. The research results display that fairness behavior will always emerge regardless of the distribution of the initial strategies. If the strategies are randomly distributed on the network, then the long-term agent fairness levels achieved are very close given unchanged learning parameters. Neighborhood size also has little effect on the fairness level attained. The simulation results also imply that WS small-world and BA scale-free networks have different effects on the spatial ultimatum game. In ultimatum game on networks with incomplete information, the WS small-world network and its variations favor the emergence of fairness behavior slightly more than the BA network where agents are heterogeneously structured. 相似文献