讲座主题：
Querying Geo-Textual Data Using Keywords and User Location
主讲人姓名及介绍：
Christian S. Jensen is Professor of Computer Science at Aalborg University, Denmark. His research concerns analytics, data management, and data-intensive systems, and its focus is on temporal and spatio-temporal analytics. Christian is an ACM and an IEEE Fellow, and he is a member of Academia Europaea, the Royal Danish Academy of Sciences and Letters, and the Danish Academy of Technical Sciences. He has received several national and international awards for his research, most recently the 2019 IEEE TCDE Impact Award. He serves on the board of Villum Fonden, a major funder of technical and natural science research in Denmark; he is President of the steering committee of the Swiss National Research Program on Big Data; and in Germany, he serves on the scientific advisory board the Max Planck Institute for Informatics. He is Editor-in-Chief of ACM Transactions on Database Systems.
报告摘要：
Large volumes of geo-tagged, textual content are available on the web, including web pages, points of interest, and microblog posts. Studies suggest that users with known geo-locations issue several billion keyword-based queries on a weekly basis that aim to retrieve such content. A prototypical query takes a user location and user-supplied keywords as arguments and returns content that is relevant to the arguments. Due perhaps to the rich semantics of geographical space and its importance to our daily lives, many different kinds of relevant spatial keyword query functionality exist. Based on recent work by the speaker and his colleagues, this lecture presents core functionality, concepts, and techniques relating to spatial keyword object ranking and querying.
