Introduction

Abstract

With the growth trends in social media, multimodal mobile sensing, and location driven sensing, increasingly larger parts of human life and related environmental attributes are getting digitized and becoming available for sense making. Real-world phenomena are now being observed by multiple media streams, each complementing the other in terms of data characteristics, observed features, perspectives, and vantage points. Many of these multimedia streams are now available in real time, and increasingly larger portion of these come inscribed with space and time semantics. The number of such media elements available (e.g., Tweets, Flickr posts, sensor updates) is already in the order of trillions [5], and computing resources required for analyzing them are becoming increasingly available. This trend continues to grow and is getting accelerated with the growing adoption of mobile devices.