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The rapid development of modern society continually transforms the social structure which leads to an increasingly distinct dual structure of higher population density in urban areas and lower density in rural areas. Such structure may induce distinctive spreading behavior of epidemics which does not happen in a single type structure. In this paper, we study the epidemic spreading of mobile agents on dual structure networks based on SIRS model. First, beyond the well known epidemic threshold for generic epidemic model that when the infection rate is below the threshold a pertinent infectious disease will die out, we find the other epidemic threshold which appears when the infection rate of a disease is relatively high. This feature of two thresholds for the SIRS model may lead to the elimination of infectious disease when social network has either high population density or low population density. Interestingly, however, we find that when a high density area is connected to a low density may cause persistent spreading of the infectious disease, even though the same disease will die out when it spreads in each single area. This phenomenon indicates the critical role of the connection between the two areas which could radically change the behavior of spreading dynamics. Our findings, therefore, provide new understanding of epidemiology pertinent to the characteristic modern social structure and have potential to develop controlling strategies accordingly. [ABSTRACT FROM AUTHOR]

This paper deals with the self-organization of simple mobile agents confined in a two-dimension rectangular area. Each agent interacts with its neighbors inside an interaction disk and moves following various types of force-driven couplings (e.g. repulsion or attraction). The agents do not know their absolute position, do not exchange messages, have no memory, and no learning capabilities. We first study the self-organization appearing in systems made-up with one sole type of agents, initially generated at random in the terrain. By changing the agent–agent repulsive interaction, we observe five different population reorganizations, namely, grouping, diffusion (that is classical), but especially interesting, crystallization (i.e., the agents group together on the vertices a regular hexagonal lattice), alignment along straight lines, and vortex dynamics. Then, we consider reorganization in systems made-up from two to five types of agents, where each pair of agent types has specific interaction parameters. The main result of this work is to show that, by only changing the agent–agent repulsion rules, one can generate hexagonal or rectangular multi-agent crystals or on the contrary, induce complete separation in regular hexagonal tiles. [ABSTRACT FROM AUTHOR]

The iterated spatial game among the mobile population is an interesting problem in the fields of biological, social and economic sciences. Inspired by some recent works, this paper concentrates on the iterated snowdrift game among movable and myopic agents. Two different decision-making schemes, namely the utility-maximum rule and the Fermi rule, are applied and examined. In the former case, cooperation is found to be enhanced by moving velocity with an upper bound. The analytical results of the model are deduced at two extreme cases when agents cannot move or move quickly. In the latter case, the influences of velocity and temptation-to-defect are much more complicated. These results allow a deeper insight of the related model as well as the emergence of cooperation. [ABSTRACT FROM AUTHOR]

Abstract: The evolutionary spatial game in a mobile population has attracted many researchers of biological, social and economic sciences. Considering some facts observed in the real world, this paper proposes a novel spatial evolutionary snowdrift game model with movable players. In this model, one player interacts only with the nearest neighbor in each turn, and makes decision in a reinforcement learning way. In a very large range of the parameters moving ability enhances cooperation, but under some special condition, velocity heavily depresses cooperation. Some explanations have also been given out by investigating the strategy-change behavior of players. The findings may be helpful in understanding cooperative behavior in natural and social systems consisting of mobile agents. [Copyright &y& Elsevier]

Abstract: Co-operation is a key factor in understanding the evolution of our society. Inspired by this issue, the individual mobility in game theory has been proved to be a very useful scenario. However, it is not realistic, as described in previous studies, that each agent has the same influence on its neighbour’s movement trait. In this work, we mainly focus on the weighted influence on the mobility of agents in the prisoner’s dilemma game. Here the weight is proportional to its degree with power exponent of , where is the adjustable parameter to control the level of heterogeneity among individuals in the network. Through numerous simulations we find that co-operation level is promoted when the heterogeneous influence factor is considered. In particular, there is an intermediate value to guarantee the optimal evolution of co-operation. Moreover, we also prove that the effect of influence weight on the enhancement of co-operation is only valid when the agent’s interaction radius is within a threshold value. We thus present a viable method of understanding the ubiquitous co-operative behaviour in nature and hope that it will inspire further studies to resolve social dilemmas. [Copyright &y& Elsevier]

Abstract: This paper analyzes the behavior of releasing messages in the MicroBlog community and presents a human dynamic model co-driven by interest and social identity. According to the empirical analysis and simulation results, the messaging interval distribution follows a power law, which is mainly influenced by the degree of users’ interests. Meanwhile, social identity plays a significant role regarding the change of interests and may slow down the decline of the latter. A positive correlation between social identity and numbers of comments or forwarding of messages is illustrated. Besides, the analysis of data for each 24 h reveals obvious differences between micro-blogging and website visits, email, instant communication, and the use of mobile phones, reflecting how people use small amounts of time via mobile Internet technology. [Copyright &y& Elsevier]

Abstract: In this paper, we study cooperative behavior among mobile agents; the agents have heterogenous view radii and they play the prisoner’s dilemma game with those being within their vision fields. It is found that the cooperation level is remarkably promoted when the heterogeneity of view radii is considered, and the degree distribution of the system is investigated to explain this interesting phenomenon. Moreover, we report that the cooperative behavior is best favored by low density, moderate view radius, and small moving speed. Our findings may be helpful in understanding cooperative behavior in natural and social systems consisting of mobile agents. [Copyright &y& Elsevier]

Abstract: We study the effects of mobility on the evolution of cooperation among mobile players, which imitate collective motion of biological flocks and interact with neighbors within a prescribed radius . Adopting the the prisoner’s dilemma game and the snowdrift game as metaphors, we find that cooperation can be maintained and even enhanced for low velocities and small payoff parameters, when compared with the case that all agents do not move. But such enhancement of cooperation is largely determined by the value of , and for modest values of , there is an optimal value of velocity to induce the maximum cooperation level. Besides, we find that intermediate values of or initial population densities are most favorable for cooperation, when the velocity is fixed. Depending on the payoff parameters, the system can reach an absorbing state of cooperation when the snowdrift game is played. Our findings may help understanding the relations between individual mobility and cooperative behavior in social systems. [Copyright &y& Elsevier]

Abstract: We study the efficacy of allelomimesis as an escape strategy of mobile agents (pedestrians) that aim to leave a two-exit room within the shortest possible time. Allelomimesis is the act of copying one’s kindred neighbors. To escape, an agent employs one of the following strategies: (1) It chooses its own route independently (non-copying, ), (2) It imitates the actions of its neighbors at all times (blind copying, ), or (3) It either copies or acts independently according to a certain probability that is set by the copying parameter . Not more than one agent could occupy a given room location. An agent’s knowledge of the two exit locations is set by its information content . When left alone, an agent with complete knowledge of the exit whereabouts () always takes the shortest possible path to an exit. We obtain plots of the (group) evacuation time and exit throughput as functions of and for cases where the two exits are near (on same room side) and far (on opposite sides of room) from each other. For an isolated agent, is inversely proportional to . The chances of escape for an isolated agent with are higher with adjacent exits. However, for an agent with the chance is better with opposite exits. In a highly occupied room (occupancy rate ) with adjacent exits, agents with escape more quickly if they employ a mixed strategy of copying and non-copying (). On the other hand, blind copying () gives agents with a better chance of escaping from the same room. For the same and values, opposite exits allow faster evacuation for agents with due to the likelihood of streaming and the lower probability of exit clogging. Streaming indicates an efficient utilization of an exit and it happens when the arcs that are formed are smaller and arch interference is less likely. Allelomimesis provides a simple yet versatile mechanism for studying the egress behavior of confined crowds in a multi-exit room. [Copyright &y& Elsevier]

Abstract: This paper studies the formation control problem for systems consisting of multiple mobile agents that are described by first-order differential equations and second-order differential equations respectively. The following issues are investigated: bounded input, disturbance, and time delay. In derivation of the main results, a blend of graph-theoretic and system-theoretic tools is employed, where local potential functions and LaSalle’s Invariant Principle play central roles. Finally, numerical examples which support the analytical results very well are also included. [Copyright &y& Elsevier]