Frequent Pattern Mining from Time-Fading Streams of Uncertain Data Carson Kai-Sang Leung and Fan Jiang DaWaK 2011 1
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Frequent Pattern Mining fromTime-Fading Streams of Uncertain
DataCarson Kai-Sang Leung and Fan Jiang
DaWaK 2011
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Outline Motivation Background Method
A Naive Algorithm: TUF-Streaming(Naive) A Space-Saving Algorithm: TUF-
Streaming(Space) A Time-Saving Algorithm: TUF-Streaming(Time)
Experimental Result Conclusion
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Motivation In past few years, several mining algorithms
have been proposed to discover frequent patterns from uncertain data. However, most of them mine frequent patterns from static databases—but not dynamic streams—of uncertain data.
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Background Mining from Static Database of
Uncertain data x:item X:itemset DB: transaction database ti:transaction the expected support of X in the DB can be
computed by summing (over all transactionst1, ..., t|DB|) the product (of existential probabilities of items within X):
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Background Mining from Uncertain data Streams with
Sliding window Bi:batch X:itemset T:time DB: transaction database the expected support of X in the current sliding
window containing batches of uncertain data in Batches inclusive can be computed as follows:
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A Naive Algorithm: TUF-Streaming(Naive)
minsup=1.0preMinsup=0.8
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(Cont.)
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(Cont.)
minsup=1.0preMinsup=0.8
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A Space-Saving Algorithm: TUF-Streaming(Space)
minsup=1.0preMinsup=0.8
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(Cont.)
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A Time-Saving Algorithm: TUF-Streaming(Time) In have frequent: {a}=1.7,{b}=1.8,{b,c}=1.44,{b,c,d}=0.86,{b,d}=1.08,{c}=1.6, {c,d}=0.96,{d}=1.3Last
batch
Last batch’s expected support
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(Cont.) In have frequent:{a},{a,d},{b},{b,c},{c},
{d}
minsup=1.0preMinsup=
0.8
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(Cont.) In have frequent:{a},{b},{b,d},{c},{d}
minsup=1.0preMinsup=
0.8
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Experimental Result
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(Cont.)
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Conclusion In this paper, we proposed tree-based mining
algorithms that can be used for mining frequent patterns from dynamic streams of uncertain data with both time-fading and landmark models.