On the semantic annotation of places in location-based social networks

In this paper, we develop a semantic annotation technique for location-based social networks to automatically annotate all places with category tags which are a crucial prerequisite for location search, recommendation services, or data clean-ing. Our annotation algorithm learns a binary support vec-tor machine (SVM) classifier for each tag in the tag space to support multi-label classification. Based on the check-in be-havior of users, we extract features of places from i) explicit patterns (EP) of individual places and ii) implicit relatedness (IR) among similar places. The features extracted from EP are summarized from all check-ins at a specific place. The features from IR are derived by building a novel network of related places (NRP) where similar places are linked by vir-tual edges. Upon NRP, we determine the probability of a category tag for each place by exploring the relatedness of places. Finally, we conduct a comprehensive experimental study based on a real dataset collected from a location-based social network, Whrrl. The results demonstrate the suitabil-ity of our approach and show the strength of taking both EP and IR into account in feature extraction