基于时空周期模式挖掘的活动语义识别方法

传统的活动语义识别研究侧重从时空轨迹的空间信息中提取人类的活动语义，对时空轨迹数据的时间特性挖掘不足。本文兼顾时间和空间特征，提出了一种基于周期模式挖掘的活动语义识别方法。首先将分离出的活动轨迹数据通过空间距离进行密度聚类分成不同轨迹簇；然后，根据轨迹簇的时序特征挖掘个体对特定位置的访问周期，基于该访问周期，并结合在该位置的停留时间，及其附近兴趣点分布等特征构建分类模型，识别人类个体的活动语义。基于签到数据和仿真数据的实验结果表明，结合周期特征的活动语义识别方法相比没有加入周期特征的实验结果有效提升识别精度20%以上，在2个相同的签到数据集下，对比其他的识别方法提升精度10%以上。

Active semantic recognition method based on spatial-temporal period pattern mining

Active semantic recognition aims to mine people’s activities from spatial-temporal data recording through the smart equipment they carry. Traditional studies paid more attention to studying the spatial features of spatial-temporal data but failed to mine temporal features adequately. Considering both features, this work proposes an active semantic recognition method based on period pattern mining. First, trajectories that have already been separated from raw trajectories are clustered based on the spatial distance. The periods of reference spots that are frequently visited by the people are then mined according to the sequence of clustering. Based on the visit period and combined with the residence time at the location and the distribution of interest points nearby, a classification model is constructed to identify the activity semantics of human individuals. The experimental results on the check-in dataset and simulation data show that the valid recognition accuracy of active semantic recognition combined with periodic characteristics increases by 20% more than that without periodic characteristics. Under the same two check-in datasets and compared with other recognition methods, the accuracy is improved by more than 10%.