Dainfos Lab invited Dr. Anders Skovsgaard from Denmark to give the talk dedicated to Scalable top-k spatio-temporal term querying.

Dr. Anders Skovsgaard is Softward Wizard and Partner at TrustSkills ApS in Aarhus, Denmark. He obtained his PhD in Computer Science from Aarhus University, working in the Data-Intensive Systems group/MADALGO primarily with Big Data algorithms. More specifically, scalable textual indexing and query processing of objects in space and time. He visited the Information and Data Management group at UCLA, Los Angeles in 2013/2014.He obtained his MSc in Computer Science from Aalborg University in 2009. Anders has worked several years in the industry and started a couple of spin-off companies related to his research.

About the talk: With the rapidly increasing deployment of Internet-connected, location-aware mobile devices, very large and increasing amounts of geo-tagged and timestamped user-generated content, such as microblog posts, are being generated. We present indexing, update, and query processing techniques that are capable of providing the top-k terms seen in posts in a user-specified spatio-temporal range. The techniques enable interactive response times in the millisecond range in a realistic setting where the arrival rate of posts exceeds today's average tweet arrival rate by a factor of 4-10. The techniques adaptively maintain the most frequent items at various spatial and temporal granularities. They extend existing frequent item counting techniques to maintain exact counts rather than approximations. An extensive empirical study with a large collection of geo-tagged tweets shows that the proposed techniques enable online aggregation and query processing at scale in realistic settings. The working language is English. The talk will be held at the Innopolis University by the address: Innopolis city, 1 Universitetskaya St, room 108. The talk starts on September 11th at 15:00.