Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China.
Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang, China.
PLoS One. 2020 Mar 26;15(3):e0230592. doi: 10.1371/journal.pone.0230592. eCollection 2020.
The quantitative understanding of human behavior is a key issue in modern science. Recently, inhomogeneous human activities have been described by bursts (consecutive activities separated by long periods of inactivity) and characterized by fat-tailed inter-event time (interval between two activities) distributions. However, the dynamics between number of activities and activity duration are still unclear. In this study, we analyzed 133 million toll-free call records from China to study the dynamics between call frequency and call duration. We confirmed that both call frequency and call duration exhibit circadian cycles and weekly cycles. By analyzing intraday patterns of these two metrics, we found the opposite volatility and clustered distributions. Results of clustering analysis showed that calling activity to toll-free numbers can be clustered into four clusters. In the "Work" cluster, the distribution of call duration was significantly different from that in the other clusters. The corresponding time of "Work" cluster was much shorter than estimates based on common sense. Intraday patterns and clustering results showed that both call frequency and call duration are primarily related to circadian cycles, the nature of human beings, and that work is a secondary factor that affects these variables. Moreover, we found a strong positive correlation between call frequency and call duration, as well as polarization of joint probability. The polarization indicates two extremes in inhomogeneous calling activity to toll-free numbers, i.e., either people are very busy or very idle. The empirical probability of the extreme was approximately four times that of random probability. Our findings may have great usage for studying the dynamics of inhomogeneous human behavior.
人类行为的定量理解是现代科学的一个关键问题。最近，非均匀的人类活动被突发活动（连续活动之间被长时间的不活动隔开）所描述，并以长尾的事件间时间（两个活动之间的间隔）分布为特征。然而，活动数量和活动持续时间之间的动态关系仍不清楚。在这项研究中，我们分析了来自中国的 1.33 亿条免费电话记录，以研究通话频率和通话持续时间之间的动态关系。我们证实，通话频率和通话持续时间都表现出昼夜节律和每周节律。通过分析这两个指标的日内模式，我们发现了相反的波动性和聚类分布。聚类分析的结果表明，拨打免费电话号码的活动可以聚类为四个集群。在“工作”集群中，通话持续时间的分布与其他集群明显不同。“工作”集群的相应时间明显短于基于常识的估计。日内模式和聚类结果表明，通话频率和通话持续时间主要与昼夜节律、人类的本性有关，而工作是影响这些变量的次要因素。此外，我们发现通话频率和通话持续时间之间存在很强的正相关，以及联合概率的极化。极化表明，不均匀的拨打免费电话活动存在两种极端情况，即要么人们非常忙碌，要么非常空闲。极端情况下的经验概率大约是随机概率的四倍。我们的发现可能对研究不均匀人类行为的动态具有重要的应用价值。
