耦合自适应智能体排队模型中的吸收相变
Absorbing phase transition in a queueing model of coupled adaptive agents
浏览论文内容
中文总结 AI 辅助
该研究构建耦合自适应智能体排队模型，揭示其存在不连续相变，得到临界度与最大群体规模，解释了人类联合/单独活动的决策机制及通信记录中的相关现象。
中文摘要 AI 辅助
是什么决定了人们是共同行动还是单独行动？许多活动无法单独完成，个体必须将这些活动与争夺相同时间的私人任务进行排序。我们在人类活动的优先队列描述框架内解决这一问题，让每个智能体选择共享任务的优先级，而非从固定分布中抽取：该联合活动的价值会因对伙伴不参与的估计风险而被折现。参与行为成为策略性选择，模型由此产生相变。我们通过鞍结分岔以闭式形式得到：维持联合活动的耦合相与吸收性独居相分离，该转变为不连续的，且独居相是吸收性的，因此除非智能体单方面坚持约一个记忆时间，否则崩溃是不可逆的，我们也计算了这一成本。促使人类动力学排队模型产生的重尾事件间统计仅在转变处的窄窗口内存在，且此处指数由耦合时间占比而非队列长度决定：非策略性模型的普适类在引入选择后不再存在。在网络上，注意力按1/(k+a)划分，并确定了一个临界度，超过该临界度则不存在耦合态，因此独居相根据Molloy–Reed准则渗流，其二阶矩在该度处被截断——形式上是对枢纽的攻击，却无攻击者。对于群体活动，临界度按(m-1)次方根下降，意味着存在最大群体规模。该转变协调了通信记录中已测量的两个量：维持关系活跃的有限容量，以及节奏被中断的关系的衰减。
英文摘要
What decides whether people do things together or separately? Many activities cannot be carried out alone, and an individual must rank them against the private tasks competing for the same time. We address this within the priority-queue description of human activity by letting each agent choose the priority of a shared task rather than drawing it from a fixed distribution: the value of the joint activity, discounted by the estimated risk that the partner will not take part. Participation becomes strategic, and the model acquires a phase transition. A coupled phase, in which joint activity is sustained, is separated from an absorbing solitary phase by a saddle-node bifurcation that we obtain in closed form. The transition is discontinuous and the solitary phase is absorbing, so collapse is irreversible unless an agent persists unilaterally for of order one memory time, a cost we also compute. The heavy-tailed interevent statistics that motivate queueing models of human dynamics survive only in a narrow window at the transition, and there the exponent is fixed by the fraction of time spent coupled rather than by queue length: the universality classes of the non-strategic model do not survive the introduction of choice. On a network, attention divides as $1/(k+a)$ and fixes a critical degree beyond which no coupled state exists, so the solitary phase percolates according to the Molloy--Reed criterion with the second moment truncated at that degree --- formally an attack on hubs, with no attacker. For group activities the critical degree falls as the $(m-1)$th root, implying a maximum group size. The transition organises two quantities already measured in communication records: a finite capacity for keeping ties active, and the decay of ties whose rhythm is interrupted.
