Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, Illinois, United States of America.
PLoS One. 2012;7(5):e37676. doi: 10.1371/journal.pone.0037676. Epub 2012 May 31.
The individual movements of large numbers of people are important in many contexts, from urban planning to disease spreading. Datasets that capture human mobility are now available and many interesting features have been discovered, including the ultra-slow spatial growth of individual mobility. However, the detailed substructures and spatiotemporal flows of mobility--the sets and sequences of visited locations--have not been well studied. We show that individual mobility is dominated by small groups of frequently visited, dynamically close locations, forming primary "habitats" capturing typical daily activity, along with subsidiary habitats representing additional travel. These habitats do not correspond to typical contexts such as home or work. The temporal evolution of mobility within habitats, which constitutes most motion, is universal across habitats and exhibits scaling patterns both distinct from all previous observations and unpredicted by current models. The delay to enter subsidiary habitats is a primary factor in the spatiotemporal growth of human travel. Interestingly, habitats correlate with non-mobility dynamics such as communication activity, implying that habitats may influence processes such as information spreading and revealing new connections between human mobility and social networks.
大量人群的个体运动在许多情境中都很重要，从城市规划到疾病传播。现在已经有捕捉人类移动性的数据集，并且已经发现了许多有趣的特征，包括个体移动性的超慢速空间增长。然而，移动性的详细子结构和时空流动——访问地点的集合和序列——还没有得到很好的研究。我们表明，个体移动性主要由经常访问的、动态接近的小地点组所支配，这些组形成了典型日常活动的主要“栖息地”，以及代表额外旅行的附属栖息地。这些栖息地与家庭或工作等典型环境不对应。在栖息地内的移动性的时间演化，构成了大部分运动，在栖息地之间具有普遍性，并且表现出与之前所有观察结果都不同的标度模式，并且当前模型无法预测。进入附属栖息地的延迟是人类旅行的时空增长的主要因素。有趣的是，栖息地与非移动性动态（如通信活动）相关联，这意味着栖息地可能会影响信息传播等过程，并揭示人类移动性和社交网络之间的新联系。
