Efficient algorithms for mining colossal patterns in high dimensional databases
Mining association rules plays an important role in decision support
systems. To mine strong association rules, it is necessary to mine
frequent patterns. There are many algorithms that have been developed to
efficiently mine frequent patterns, such as Apriori, Eclat, FP-Growth,
PrePost, and FIN. However, these are only efficient with a small number
of items in the database. When a database has a large number of items
(from thousands to hundreds of thousands) but the number of transactions
is small, these algorithms cannot run when the minimum support
threshold is also small (because the search space is huge). This thus
causes the problem of mining colossal patterns in high dimensional
databases. In 2012, Sohrabi and Barforoush proposed the BVBUC algorithm
for training colossal patterns based on a bottom up scheme. However,
this needs more time to check subsets and supersets, because it
generates a lot of candidates and consumes more memory to store these.
In this paper we propose new, efficient algorithms for mining colossal
patterns. Firstly, the CP (Colossal Pattern)-tree is designed. Next, we
develop two theorems to rapidly compute patterns of nodes and prune
nodes without the loss of information in colossal patterns. Based on the
CP-tree and these theorems, an algorithm (named CP-Miner) is proposed
to solve the problem of mining colossal patterns. A Sorting strategy for
efficiently mining colossal patterns is thus developed. This strategy
helps to reduce the number of significant candidates and the time needed
to check subsets and supersets. The PCP-Miner algorithm, which Uses
this strategy, is then proposed, and we also conduct experiments to show
the efficiency of these algorithms. (C) 2017 Elsevier B.V. All rights
reserved.
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