www-ai.cs.tu-dortmund.de/LEHRE/FACHPROJEKT/SS12/paper/counting/cheng2006.pdf
paper555.dvi
consumes less memory than do the state-of-the-art algorithms [5, 2], while attains the same level of accuracy.
2 Preliminaries
Let I = {x1, x2, . . . , xm} be a set of items. An itemset is a subset of I. A [...] T ) =
l∑
i=j
s̃up(X, ti). 2
Based on the computed support of an itemset, we apply a progressively in- creasing MST function to define a semi-frequent itemset.
Definition 2 (Semi-Frequent Itemset) Let [...] k = τ − o + 1 and to is the oldest time unit such that s̃up(X, to) > 0. 2
The first term mk in the minsup function in Definition 2 is the minimum support required for an FI over T k, while the second term …
