1 http://web-ngram.research.microsoft.com/info/ 2 http://www.wikipedia.org/ The objective function is defined as: where d is a tweet from Tweet stream, {s 1 , ..., s m } are the segments in tweet d and C is the function which measures the stickiness of a tweet or segment.
: where the length L(s) is defined in Eq 3, and a longer s makes it typically less sticky.