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1.
Evolutionary prisoner’s dilemma on Newman-Watts social networks with an asymmetric payoff distribution mechanism
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In this paper, we introduce an asymmetric payoffdistribution mechanism into the evolutionary prisoner's dilemma game(PDG) on Newman--Watts social networks, and study its effects on theevolution of cooperation. The asymmetric payoff distributionmechanism can be adjusted by the parameter α: if α>0,the rich will exploit the poor to get richer; if α<0, therich are forced to offer part of their income to the poor.Numerical results show that the cooperator frequency monotonouslyincreases with α and is remarkably promoted when α>0.The effects of updating order and self-interaction are alsoinvestigated. The co-action of random updating and self-interactioncan induce the highest cooperation level. Moreover, we employ the Ginicoefficient to investigate the effect of asymmetric payoffdistribution on the the system's wealth distribution. This work maybe helpful for understanding cooperative behaviour and wealthinequality in society. 相似文献
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We study the effect of accumulative payoff on the evolution of cooperation in the evolutionary prisoner’s dilemma on a square lattice. We introduce a decaying factor for the accumulative payoff, which characterizes the extent that the historical payoff is accumulated. It is shown that for fixed values of the temptation to defect, the density of cooperators increases with the value of the decaying factor. This indicates that the more the historical payoff is involved, the more favourable cooperators become. In the critical region where the cooperator density converges to zero, cooperators vanish according to a power-law-like behaviour. The associated exponents agree approximately with the two-dimensional directed percolation and depend weakly on the value of the decaying factor. 相似文献
3.
Cooperation influenced by the correlation degree of two-layered complex networks in evolutionary prisoner’s dilemma games
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An evolutionary prisoner's dilemma game is investigated ontwo-layered complex networks respectively representing interactionand learning networks in one and two dimensions. A parameter q isintroduced to denote the correlation degree between the two-layerednetworks. Using Monte Carlo simulations we studied the effects ofthe correlation degree on cooperative behaviour and found that thecooperator density nontrivially changes with q for differentpayoff parameter values depending on the detailed strategy updatingand network dimension. An explanation for the obtained results isprovided. 相似文献
4.
Adaptive co-evolution of strategies and network leading to optimal cooperation level in spatial prisoner’s dilemma game
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We study evolutionary prisoner's dilemma game on adaptivenetworks where a population of players co-evolves with theirinteraction networks. During the co-evolution process, interactedplayers with opposite strategies either rewire the link between themwith probability $p$ or update their strategies with probability$1-p$ depending on their payoffs. Numerical simulation shows thatthe final network is either split into some disconnected communitieswhose players share the same strategy within each community or formsa single connected network in which all nodes are in the samestrategy. Interestingly, the density of cooperators in the finalstate can be maximised in an intermediate range of $p$ via thecompetition between time scale of the network dynamics and that ofthe node dynamics. Finally, the mean-field analysis helps tounderstand the results of numerical simulation. Our results mayprovide some insight into understanding the emergence of cooperationin the real situation where the individuals' behaviour and theirrelationship adaptively co-evolve. 相似文献
5.
Integrating the environmental factor into the strategy updating rule to promote cooperation in evolutionary games
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Many previous studies have shown that the environment plays an important role for social individuals.In this paper,we integrate the environmental factor,which is defined as the average payoff of all a player’s neighbours,with the standard Fermi updating rule by introducing a tunable parameter,ω.It is found that the level of cooperation increases remarkably,and that the cooperators can better resist the invasion of defection with an increase in ω.This interesting phenomenon is then explained from a microscopic view.In addition,the universality of this mechanism is also proved with the help of the small-world network and the random regular graph.This work may be helpful in understanding cooperation behaviour in species from unicellular organisms up to human beings. 相似文献
6.
A weight’s agglomerative method for detecting communities in weighted networks based on weight’s similarity
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This paper proposes the new definition of the community structure of the weighted networks that groups of nodes in which the edge's weights distribute uniformly but at random between them. It can describe the steady connections between nodes or some similarity between nodes' functions effectively. In order to detect the community structure efficiently, a threshold coefficient κ to evaluate the equivalence of edges' weights and a new weighted modularity based on the weight's similarity are proposed. Then, constructing the weighted matrix and using the agglomerative mechanism, it presents a weight's agglomerative method based on optimizing the modularity to detect communities. For a network with n nodes, the algorithm can detect the community structure in time O(n2log2n). Simulations on networks show that the algorithm has higher accuracy and precision than the existing techniques. Furthermore, with the change of κ the algorithm discovers a special hierarchical organization which can describe the various steady connections between nodes in groups. 相似文献
7.
Repeated games describe situations where players interact with each other in a dynamic pattern and make decisions according to outcomes of previous stage games. Very recently, Press and Dyson have revealed a new class of zero-determinant(ZD) strategies for the repeated games, which can enforce a fixed linear relationship between expected payoffs of two players, indicating that a smart player can control her unwitting co-player’s payoff in a unilateral way [Proc. Acad. Natl. Sci.USA 109, 10409(2012)]. The theory of ZD strategies provides a novel viewpoint to depict interactions among players,and fundamentally changes the research paradigm of game theory. In this brief survey, we first introduce the mathematical framework of ZD strategies, and review the properties and constrains of two specifications of ZD strategies, called pinning strategies and extortion strategies. Then we review some representative research progresses, including robustness analysis,cooperative ZD strategy analysis, and evolutionary stability analysis. Finally, we discuss some significant extensions to ZD strategies, including the multi-player ZD strategies, and ZD strategies under noise. Challenges in related research fields are also listed. 相似文献
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Though numerous researches have shown that tie strengths play a key role in the formation of collective behavior in social networks, little work has been done to explore their impact on the outcome of evolutionary games. In this Letter, we studied the effect of tie strength in the dynamics of evolutionary prisoner?s dilemma games by using online social network datasets. The results show that the fraction of cooperators has a non-trivial dependence on tie strength. Weak ties, just like previous researches on epidemics and information diffusion have shown, play a key role by the maintenance of cooperators in evolutionary prisoner?s dilemma games. 相似文献
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Many previous studies have shown that the environment plays an important role for social individuals. In this paper, we integrate the environmental factor, which is defined as the average payoff of all a player's neighbours, with the standard Fermi updating rule by introducing a tunable parameter, ω. It is found that the level of cooperation increases remarkably, and that the cooperators can better resist the invasion of defection with an increase in ω. This interesting phenomenon is then explained from a microscopic view. In addition, the universality of this mechanism is also proved with the help of the small-world network and the random regular graph. This work may be helpful in understanding cooperation behaviour in species from unicellular organisms up to human beings. 相似文献
12.
LI Hai-Hong CHENG Hong-Yan DAI Qiong-Lin JU Ping ZHANG Mei YANG Jun-Zhong 《理论物理通讯》2011,56(5):813-818
We investigate the evolutionary prisoner's dilemma game in structured populations by introducing dimers, which are defined as that two players in each dimer always hold a same strategy. We find that influences of dimers on cooperation depend on the type of dimers and the population structure. For those dimers in which players interact with each other, the cooperation level increases with the number of dimers though the cooperation improvement leveldepends on the type of network structures. On the other hand, the dimers, in which there are not mutual interactions, will not do any good to the cooperation level in a single community, but interestingly, will improve the cooperation level in a population with two communities. We explore the relationship between dimers and self-interactions and find that the effects of dimers are similar to that of self-interactions. Also, we find that the dimers, which are established over two communities in a multi-community network, act as one type of interaction through which information between communities is communicated by the requirement that two players in a dimer hold a same strategy. 相似文献
13.
We investigate cooperative behaviors of lattice-embeddedscale-free networking agents in the prisoner's dilemma game model byemploying two initial strategy distribution mechanisms, which are specificdistribution to the most connected sites (hubs) and random distribution. Ourstudy indicates that the game dynamics crucially depends on the underlyingspatial network structure with different strategy distribution mechanism.The cooperators' specific distribution contributes to an enhanced level ofcooperation in the system compared with random one, and cooperation isrobust to cooperators' specific distribution but fragile to defectors' specific distribution. Especially, unlike the specific case, increasing heterogeneity of network does not always favor the emergence of cooperation under random mechanism. Furthermore, we study the geographical effects and find that the graphically constrained network structure tends to improve the evolution of cooperation in random case and in specific one for a large temptation to defect. 相似文献
14.
This paper studies the continuous prisoner's dilemma games (CPDG) on Barabasi-Albert (BA) networks. In the model, each agent on a vertex of the networks makes an investment and interacts with all of his neighboring agents. Making an investment is costly, but which benefits its neighboring agents, where benefit and cost depend on the level of investment made. The payoff of each agent is given by the sum of payoffs it receives in its interactions with all its neighbors. Not only payoff, individual's guilty emotion in the games has also been considered. The negative guilty emotion produced in comparing with its neighbors can reduce the utility of individuals directly. We assume that the reduction amount depends on the individual's degree and a baseline level parameter. The group's cooperative level is characterized by the average investment of the population. Each player makes his investment in the next step based on a convex combination of the investment of his best neighbors in the last step, his best history strategies in the latest steps which number is controlled by a memory length parameter, and a uniformly distributed random number. Simulation results show that this degree-dependent guilt mechanism can promote the evolution of cooperation dramatically comparing with degree-independent guilt or no guilt cases. Imitation, memory, uncertainty coefficients and network structure also play determinant roles in the cooperation level of the population. All our results may shed some new light on studying the evolution of cooperation based on network reciprocity mechanisms. 相似文献
15.
In this study,we propose a spatial prisoner’s dilemma game model with a 2-stage strategy updating rule,and focus on the cooperation behavior of the system.In the first stage,i.e.,the pre-learning stage,a focal player decides whether to update his strategy according to the pre-learning factor β and the payoff difference between himself and the average of his neighbors.If the player makes up his mind to update,he enters into the second stage,i.e.,the learning stage,and adopts a strategy of a randomly selected neighbor according to the standard Fermi updating rule.The simulation results show that the cooperation level has a non-trivial dependence on the pre-learning factor.Generally,the cooperation frequency decreases as the pre-learning factor increases;but a high cooperation level can be obtained in the intermediate region of 3 < β < 1.We then give some explanations via studying the co-action of pre-learning and learning.Our results may sharpen the understanding of the influence of the strategy updating rule on evolutionary games. 相似文献