Resumen
With the widespread use of the location-based social networks (LBSNs), the next point-of-interest (POI) recommendation has become an essential service, which aims to understand the user?s check-in behavior at the current moment by analyzing and mining the correlations between the user?s check-in behaviors within his/her historical trajectory and then recommending the POI that the user is most likely to visit at the next time step. However, the user?s check-in trajectory presents extremely irregular sequential patterns, such as spatial?temporal patterns, semantic patterns, etc. Intuitively, the user?s visiting behavior is often accompanied by a certain purpose, which makes the check-in data in LBSNs often have rich semantic activity characteristics. However, existing research mainly focuses on exploring the spatial?temporal sequential patterns and lacks the mining of semantic information within the trajectory, so it is difficult to capture the user?s visiting intention. In this paper, we propose a self-attention- and multi-task-based method, called MSAN, to explore spatial?temporal and semantic sequential patterns simultaneously. Specifically, the MSAN proposes to mine the user?s visiting intention from his/her semantic sequence and uses the user?s visiting intention prediction task as the auxiliary task of the next POI recommendation task. The user?s visiting intention prediction uses hierarchical POI category attributes to describe the user?s visiting intention and designs a hierarchical semantic encoder (HSE) to encode the hierarchical intention features. Moreover, a self-attention-based hierarchical intention-aware module (HIAM) is proposed to mine temporal and hierarchical intention features. The next POI recommendation uses the self-attention-based spatial?temporal-aware module (STAM) to mine the spatial?temporal sequential patterns within the user?s check-in trajectory and fuses this with the hierarchical intention patterns to generate the next POI list. Experiments based on two real datasets verified the effectiveness of the model.