Title: "Tracking the Evolution Dynamics of Place Networks in Foursquare" ABSTRACT            Human mobility has been a hot topic of interest for researchers due to its importance for many application scenarios that include nearby place search, mobile context awareness or mobile advertising.  Despite the bevy of research on human mobility patterns analysis and prediction modeling of individual users, however, little attention has been put on the mobility patterns of user collectives across places in a city. In this talk, we will exploit network analysis techniques to view human movement in urban environments from the perspective of an aggregate networked system where nodes are Foursquare venues. We will discuss the geometric properties of place networks in a large number of metropolitan areas around the world and how those compare to other well studied types of networks, such as on-line social networks or the web. Next, we will shed light on the growth patterns of place networks in terms of node and edge generation processes. Motivated by the fact that a large number of new links is emerging over time in those networks, we will define a link prediction task in this novel application domain with the aim to predict future interactions between Foursquare venues. The talk will close by providing a head to head comparison over the prediction task amongst the well-known, in human mobility literature, gravity models, network-based techniques as well as supervised learning algorithms.

BIOGRAPHICAL NOTE Dr. Anastasios Noulas is a Research Associate in the Computer Laboratory at the University of Cambridge. He has over 6 years of interdisciplinary scientific research experience on spatial data mining, dynamically evolving social networks, human mobility and recommender systems, with publications in top-tier conferences that include ICWSM, KDD and ICDM alongside journals of multi-disciplinary interest. After completing his MEng in Computer Science at UCL, Anastasios went to Cambridge to do his PhD, which focused on data analysis and modelling in location-based online social networks and related systems and applications with broad interest in social networks, human mobility and urban activity modelling. After finishing his PhD in 2013 Anastasios moved to Foursquare's Data Science Team as a Visiting Research Scientist and subsequently returned to the Computer Laboratory as a Research Associate, working on the EPSRC GALE (Global Accessibility to Local Experience) Project. During 2014 Anastasios was a Visiting Professor in the Department of Mathematics at the University of Namur, Belgium, where he taught a Master's Course on Location-based Services. Anastasios also works as a Data Scientist & Research Consultant at Piinpoint, a Start-Up that provides an on-line analytics platform for retail store localisation.