Timing It Just Right: Learning and Optimization of High Dimensional Event Cascades

Series
Applied and Computational Mathematics Seminar
Time
Monday, February 24, 2014 - 2:00pm for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Le Song – Georgia Tech CSE
Organizer
Martin Short
Dynamical processes, such as information diffusion in social networks, gene regulation in biological systems and functional collaborations between brain regions, generate a large volume of high dimensional “asynchronous” and “interdependent” time-stamped event data. This type of timing information is rather different from traditional iid. data and discrete-time temporal data, which calls for new models and scalable algorithms for learning, analyzing and utilizing them. In this talk, I will present methods based on multivariate point processes, high dimensional sparse recovery, and randomized algorithms for addressing a sequence of problems arising from this context. As a concrete example, I will also present experimental results on learning and optimizing information cascades in web logs, including estimating hidden diffusion networks and influence maximization with the learned networks. With both careful model and algorithm design, the framework is able to handle millions of events and millions of networked entities.