Hysteresis behavior and nonequilibrium phase transition in a one-dimensional evolutionary game model

We investigate a simple evolutionary game model in one dimension. It is found that the system exhibits a discontinuous phase transition from a defection state to a cooperation state when the b payoff of a defector exploiting a cooperator is small. Furthermore, if b is large enough, then the system exhibits two continuous phase transitions between two absorbing states and a coexistence state of cooperation and defection, respectively. The tri-critical point is roughly estimated. Moreover, it is found that the critical behavior of the continuous phase transition with an absorbing state is in the directed percolation universality class.     

大学物理实验“课程思政”的探索与实践——以“金属杨氏模量的测定”为例

在立德树人视域下,江南大学理学院物理实验中心开展了大学物理实验"课程思政"的探索与实践,逐步建立了在实验中思政、在思政中创新、在创新中树人的教学改革模式,取得了丰硕的实践成果.以"金属杨氏模量的测定"为例,呈现了实践课程渗透课程思政,并将之落到实处的具体实施方案.     

带有乘积型多目标权函数的调度谈判问题

在供应链环境下的生产活动中,各成员对所辖资源具有独立的支配权,因此需要合理的机制使得协同调度方案得以实施,以提高供应链整体的效率.研究由具备不同讨价还价能力的成员所组成的供应链,建立了以纳什讨价还价公理体系为基础的调度谈判模型.在装配系统中,讨论两供应商关于交付顺序的协商.为求取纳什谈判解,提出了一类新的以多目标乘积项作为目标函数的调度问题.对于单机型供应商,新问题的计算复杂性尚未确定,设计了一种多项式时间的启发式算法以求得近优解,并通过数值算例进行验证.该谈判模型为供应链中各成员提供了一种合理的调度协调机制.     

随机需求条件下不同合作方式的供应链利润分配研究

考虑由一个制造商和一个分销商组成的二级供应链,引入共享契约作为利润再分配的手段,建立了随机需求条件下供应链的Stackberg博弈和张伯伦利润分配模型,研究表明:核心企业制造商可以通过调整利润分配参数使供应链各节点实现共赢,同时在供应链节点企业竞争地位不对等的情况下,采用张伯伦模型的合作方式会使节点利润更优.     

Cooperative game theory approach to allocating benefits of horizontal cooperation

Logistics costs in general, and transportation costs in particular, represent a large fraction of the operating costs of many companies. One way to try to reduce these costs is through horizontal cooperation among shippers. Thus, when the transportation needs of two or more companies are merged, their collective transportation requirements can be met at lower cost. The attainable cost savings are due to economies of scale, which translate into cheaper rates due to increased negotiation power, use of larger vehicles and bundling of shipments. In this paper, a linear model is presented and used to study the cost savings that different companies may achieve when they merge their transportation requirements. On the one hand, solving this optimization model for different collaboration scenarios allows testing and quantifying the synergies among different potential partners, thus identifying the most profitable collaboration opportunities. On the other, the problem of allocating the joint cost savings of the cooperation is tackled using cooperative game theory. The proposed approach is illustrated with an example in which different cooperative game solution concepts are compared. Extensive numerical experiments have also been carried out to gain insight into the properties of the corresponding cost savings game and the behavior of the different solution concepts.     

Prisoner's dilemma game on adaptive networks under limited foresight

We study the emergence of cooperation in an environment where players in prisoner's dilemma game (PDG) not only update their strategies but also change their interaction relations. Different from previous studies in which players update their strategies according to the imitation rule, in this article, the strategies are updated with limited foresight. We find that two absorbing states—full cooperation and full defection—can be reached, assuming that players can delete interaction relations unilaterally, but new relations can only be created with the mutual consent of both partners. Simulation experiments show that high levels of cooperation in large populations can be achieved when the temptation to defect in PDG is low. Moreover, we explore the factors which influence the level of cooperation. These results provide new insights into the cooperation in social dilemma and into corresponding control strategies. © 2012Wiley Periodicals, Inc. Complexity, 2012     

Effects of Inertia on Evolutionary Prisoner's Dilemma Game

Considering the inertia of individuals in real life,we propose a modified Fermi updating rule,where the inertia of players is introduced into evolutionary prisoner's dilemma game(PDG) on square lattices.We mainly focus on how the inertia affects the cooperative behavior of the system.Interestingly,we find that the cooperation level has a nonmonotonic dependence on the inertia:with small inertia,cooperators will soon be invaded by defectors;with large inertia,players are unwilling to change their strategies and the cooperation level remains the same as the initial state;while a moderate inertia can induce the highest cooperation level.Moreover,effects of environmental noise and individual inertia are studied.Our work may be helpful in understanding the emergence and persistence of cooperation in nature and society.     

Behavior of Collective Cooperation Yielded by Two Update Rules in Social Dilemmas:Combining Fermi and Moran Rules

We combine the Fermi and Moran update rules in the spatial prisoner's dilemma and snowdrift games to investigate the behavior of collective cooperation among agents on the regular lattice.Large-scale simulations indicate that,compared to the model with only one update rule,the cooperation behavior exhibits the richer phenomena,and the role of update dynamics should be paid more attention in the evolutionary game theory.Meanwhile,we also observe that the introduction of Moran rule,which needs to consider all neighbor's information,can markedly promote the aggregate cooperation level,that is,randomly selecting the neighbor proportional to its payoff to imitate will facilitate the cooperation among agents.Current results will contribute to further understand the cooperation dynamics and evolutionary behaviors within many biological,economic and social systems.     

低碳供应链纵向减排合作下的政府补贴策略

为了研究低碳供应链减排合作的政府补贴问题,分别构建了在纳什博弈、斯塔克尔伯格博弈和供应链集中决策三种不同的博弈关系下,政府对制造商和零售商合作减排投入进行补贴的博弈模型。分析了企业的最优减排成本投入和政府的最优补贴率,并进一步讨论了政府补贴行为和企业选择减排合作行为之间的互动博弈。研究显示:政府提供的减排补贴和企业的收益随着供应链上下游合作的紧密程度不同而不同,在纳什博弈下最高,在集中决策下最低,斯塔克尔伯格博弈下介于两者之间。比较了力量不对等供应链中企业分别处于领导者和跟随者时获得的政府补贴的差异。同时在政府补贴行为和供应链企业合作行为的交互博弈中,政府的最优策略是不对任何一方实行减排补贴。     

多归属情形下产业间平台合作的经济效应

本文针对合作后平台用户固有收益水平提高这一特征,在用户多归属情形下构建双寡头Hotelling竞争模型,分析了产业间平台合作的经济效应。研究发现,随着合作带来参与平台用户固有收益提高,该平台两边用户定价、价格非对称性和用户规模均上升。对非合作平台,合作会降低其双边用户定价和用户规模,而合作对定价非对称性的影响,则须视平台差异的程度而定。研究还表明,合作提高了参与平台利润,降低了非参与平台利润,同时还增加了消费者总剩余和社会总福利。这启示规制机构在对双边平台合作进行规制时要特别谨慎,切忌过度干预。