Step 1: Identifying k time intervals 1. compute local maxima/minima of the cohesive density curve; 2. extend local maxima/minima to peaks/valleys of the curve 3. generate time intervals containing local maxima 4. find the top-k time intervals having the largest positive density local maximum T=20 mestamps j local minimum Time complexity: O((T+h ED, h is the of local maxima/minima 13Step 1: Identifying k time intervals 13 1. compute local maxima/minima of the cohesive density curve; 2. extend local maxima/minima to peaks/valleys of the curve; 3. generate time intervals containing local maxima; 4. find the top-k time intervals having the largest positive cdensity; [i, j] [i, j] Time complexity: O((T+h2 )|E|), h is the # of local maxima/minima