The Magnificent EMM Margaret H. Dunham Michael Hahsler, Mallik Kotamarti, Charlie Isaksson CSE Department Southern Methodist University Dallas, Texas 75275 lyle.smu.edu/~mhd [email protected] This material is based upon work.
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Transcript The Magnificent EMM Margaret H. Dunham Michael Hahsler, Mallik Kotamarti, Charlie Isaksson CSE Department Southern Methodist University Dallas, Texas 75275 lyle.smu.edu/~mhd [email protected] This material is based upon work.
The Magnificent EMM
Margaret H. Dunham
Michael Hahsler, Mallik Kotamarti, Charlie Isaksson
CSE Department
Southern Methodist University
Dallas, Texas 75275
lyle.smu.edu/~mhd
[email protected]
This material is based upon work supported by the National Science Foundation under Grant No IIS-0948893.
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Objectives/Outline
EMM Overview
EMM + Stream Clustering
EMM + Bioinformatics
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Objectives/Outline
EMM Overview
Why
What
How
EMM + Stream Clustering
EMM + Bioinformatics
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Lots of Questions
Why don’t data miners practice what
they preach?
Continuous
Learning
Why is training usually viewed as a
one time thing?
Interleave
learning &
application
Why do we usually ignore the temporal
aspect of data streams?
Add time to
online clustering
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MM
A first order Markov Chain is a finite or countably infinite
sequence of events {E1, E2, … } over discrete time
points, where Pij = P(Ej | Ei), and at any time the future
behavior of the process is based solely on the current
state
A Markov Model (MM) is a graph with m vertices or states,
S, and directed arcs, A, such that:
S ={N1,N2, …, Nm}, and
A = {Lij | i 1, 2, …, m, j 1, 2, …, m} and Each arc,
Lij = <Ni,Nj> is labeled with a transition probability
Pij = P(Nj | Ni).
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Problem with Markov Chains
The required structure of the MC may not be certain
at the model construction time.
As the real world being modeled by the MC
changes, so should the structure of the MC.
Not scalable – grows linearly as number of events.
Our solution:
Extensible Markov Model (EMM)
Cluster real world events
Allow Markov chain to grow and shrink
dynamically
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EMM (Extensible Markov Model)
Time Varying Discrete First Order Markov
Model
Continuously evolves
Nodes are clusters of real world states.
Learning continues during prediction phase.
Learning:
Transition probabilities between nodes
Node labels (centroid of cluster)
Nodes are added and removed as data
arrives
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EMM Definition
Extensible Markov Model (EMM): at any time
t, EMM consists of an MC with designated
current node, Nn, and algorithms to modify
it, where algorithms include:
EMMCluster, which defines a technique for
matching between input data at time t + 1
and existing states in the MC at time t.
EMMIncrement algorithm, which updates
MC at time t + 1 given the MC at time t and
clustering measure result at time t + 1.
EMMDecrement algorithm, which removes
nodes from the EMM when needed.
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EMM Cluster
Nearest Neighbor
If none “close” create new node
Labeling of cluster is centroid of
members in cluster
O(n)
Here n is the number of states
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EMM Increment
<18,10,3,3,1,0,0>
<17,10,2,3,1,0,0>
<16,9,2,3,1,0,0>
<14,8,2,3,1,0,0>
2/3
2/3
2/21
2/3
1/1
1/2
1/2
N3
N1
1/3
N2
1/1
1/2
1/1
<14,8,2,3,0,0,0>
<18,10,3,3,1,1,0.>
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EMMDecrement
N1
N3
1/3
1/3
2/2
1/3
N2
1/2
N5
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N1
1/3
N3
1/3
1/6
Delete N2
1/6
1/3
N6
N5
1/6
N6
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EMM Advantages
Dynamic
Adaptable
Use of clustering
Learns rare event
Scalable:
Growth of EMM is not linear on size of
data.
Hierarchical feature of EMM
Creation/evaluation quasi-real time
Distributed / Hierarchical extensions
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EMM Sublinear Growth
Servent Data
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Growth Rate Automobile Traffic
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Minnesota Traffic Data
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EMM River Prediction
8
7
Water Level (m)
6
5
4
3
2
1
0
1
48 95 142 189 236 283 330 377 424 471 518 565 612 659
Input Time Series
RLF Prediction
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EMM Prediction
Observed
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Determining Rare Event
Occurrence Frequency (OFi) of an EMM
state Si is normalized count of state:
OF i n i / n i
i
Normalized Transition Probability (NTPmn),
from one state, Sm, to another, Sn, is a
normalized transition Count:
NTP
m, n
( C m , n ) /( n i )
i
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EMM Rare Event Detection
Ozone Data, UCI ML, Jaccard similarity,
2536 instances, 73 attributes, 73 ozone days
Intrusion Data, Train DARPA 1999, Test DARPA 2000,
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Objectives/Outline
EMM Overview
EMM + Stream Clustering
Handle evolving clusters
Incorporate time in clustering
EMM + Bioinformatics
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Stream Data
A growing number of applications generate streams
of data.
Computer network monitoring data
Call detail records in telecommunications
Highway transportation traffic data
Online web purchase log records
Sensor network data
Stock exchange, transactions in retail chains, ATM
operations in banks, credit card transactions.
Clustering techniques play a key role in modeling
and analyzing this data.
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Stream Data Format
Events arriving in a stream
At any time, t, we can view the state
of the problem as represented by a
vector of n numeric values:
Vt = <S1t, S2t, ..., Snt>
V1
S1
S2
…
Sn
S11
S21
…
Sn1
V2
S12
S22
…
Sn2
…
…
…
…
…
Vq
S1q
S2q
…
Snq
Time
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Traditional Clustering
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TRAC-DS (Temporal Relationship
Among Clusters for Data Streams)
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Motivation
Temporal Ordering is a major feature of
stream data.
Many stream applications depend on this
ordering
Prediction of future values
Anomaly (rare event) detection
Concept drift
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Stream Clustering Requirements
Dynamic updating of the clusters
Completely online
Identify outliers
Identify concept drifts
Barbara [2]:
compactness
fast
incremental processing
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Data Stream Clustering
At each point in time a data stream clustering ζ is
a partitioning of D', the data seen thus far.
Instead of the whole partitions C1, C2,..., Ck only
synopses Cc1,Cc2,...,Cck are available and k is
allowed to change over time.
The summaries Cci with i =1, 2,...,k typically
contain information about the size, distribution
and location of the data points in Ci.
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TRAC-DS NOTE
TRAC-DS is not:
Another stream clustering
algorithm
TRAC-DS is:
A new way of looking at clustering
Built on top of an existing clustering
algorithm
TRAC-DS may be used with any
stream clustering algorithm
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TRAC-DS Overview
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TRAC-DS Definition
Given a data stream clustering ζ, a temporal
relationship among clusters (TRAC-DS) overlays a
data stream clustering ζ with a EMM M, in such a
way that the following are satisfied:
(1) There is a one-to-one correspondence
between the clusters in ζ and the states S in M.
(2) A transition aij in the EMM M represents the
probability that given a data point in cluster i,
the next data point in the data stream will
belong to cluster j with i; j = 1; 2; : : : ; k.
(3) The EMM M is created online together with the
data stream clustering
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Stream Clustering Operations *
qassign point(ζ,x): Assigns the new data point x
to an existing cluster.
qnew cluster(ζ,x): Create a new cluster.
qremove cluster(ζ,x): Removes a cluster. Here x
is the cluster, i, to be removed. In this case the
associated summary Cci is removed from ζ and
k is decremented by one.
qmerge clusters(ζ,x): Merges two clusters.
qfade clusters(ζ,x): Fades the cluster structure.
qsplit clusters(ζ,x): Splits a cluster.
* Inspired by MONIC [13]
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TRAC-DS Operations
rassign point(M,sc,y): Assigns the new data point
to the state representing an existing cluster
rnew cluster(M,sc,y): Create a state for a new
cluster.
rremove cluster(M,sc,y): Removes state.
rmerge clusters(M,sc,y): Merges two states.
rfade clusters(M,sc,y): Fades the transition
probabilities using an exponential decay f(t)=2−λt
rsplit clusters(M,sc,y): Splits states. Y clustering
operations.
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TRAC-DS Example
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Objectives/Outline
EMM Overview
EMM + Stream Clustering
EMM + Bioinformatics
Background
Preprocessing
Classification
Differentiation
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DNA
Basic building blocks of organisms
Located in nucleus of cells
Composed of 4 nucleotides
Two strands bound together
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http://www.visionlearning.com/library/module_viewer.php?mi
d=63
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Central Dogma: DNA -> RNA ->
Protein
DNA
CCTGAGCCAACTATTGATGAA
transcription
RNA
CCUGAGCCAACUAUUGAUGAA
translation
Protein
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Amino Acid
www.bioalgorithms.info; chapter 6; Gene Prediction
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RNA
Ribonucleic Acid
Contains A,C,G but U (Uracil) instead
of T
Single Stranded
May fold back on itself
Needed to create proteins
Move around cells – can act like a
messenger
mRNA – moves out of nucleus to
other parts of cell
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The Magical 16s
Ribosomal RNA (rRNA) is at the heart of the
protein creation process
16S rRNA
About 1542 nucleotides in length
In all living organisms
Important in the classification of
organisms into phyla and class
PROBLEM: An organism may actually
contain many different copies of 16S, each
slightly different.
OUR WORK: Can we use EMM to quantify
this diversity? Can we use it to classify
different species of the same genus?
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Using EMM with RNA Data
acgtgcacgtaactgattccggaaccaaatgtgcccacgtcga
Moving Window
Pos 0-8
Pos 1-9
A
2
1
C
3
3
G
3
3
T
1
2
4
2
1
…
Pos 34-42 2
Construct EMM with nodes
representing clusters of count vectors
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EMM for Classification
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TRAC-DS and Bioinformatics
Efficient
Alignment free sequence analysis
Clustering reduces size of model
Flexible
Any sequence
Applicability to Metagenomics
Scoring based on similarity between EMMs
or EMM and input sequence
Applications
Classification
Differentiation
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Profile EMMs for Organism Classification
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Profile EMM – E Coli
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Differentiating Strains
Is it possible to identify different species of
same genus?
Initial test with EMM:
Bacillus has 21 species
Construct EMM for each species using
training set (64%)
Test by matching unknown strains (36%)
and place in closest EMM
All unknown strains correctly classified
except one: accuracy of 95%
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Bibliography
1)
2)
3)
4)
5)
6)
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8)
9)
10)
11)
12)
13)
C. C. Aggarwal, J. Han, J. Wang, and P. S. Yu. A framework for clustering evolving data streams. Proceedings of the International
Conference on Very Large Data Bases (VLDB), pp 81-92, 2003.
D. Barbara, “Requirements for clustering data streams,” SIGKDD Explorations, Vol 3, No 2, pp 23-27, 2002.
Margaret H. Dunham, Donya Quick, Yuhang Wang, Monnie McGee, Jim Waddle, “Visualization of DNA/RNA Structure using Temporal
CGRs,”Proceedings of the IEEE 6th Symposium on Bioinformatics & Bioengineering (BIBE06), October 16-18, 2006, Washington D.C. ,pp
171-178.
S. Guha, A. Meyerson, N. Mishra, R. Motwani, and L. O'Callaghan, “Clustering data streams: Theory and practice,” IEEE Transactions on
Knowledge and Data Engineering, Vol 15, No 3, pp 515-528, 2003.
Michael Hahsler and Margaret H. Dunham, “TRACDS: Temporal Relationship Among Clusters for Data Streams,” October 2009, submitted
to SIAM International Conference on Data Mining.
Jie Huang, Yu Meng, and Margaret H. Dunham, “Extensible Markov Model,” Proceedings IEEE ICDM Conference, November 2004, pp 371374.
Charlie Isaksson, Yu Meng, and Margaret H. Dunham, “Risk Leveling of Network Traffic Anomalies,” International Journal of Computer
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Charlie Isaksson and Margaret H. Dunham, “A Comparative Study of Outlier Detection,” July 2009, Proceedings of the IEEE MLDM
Conference, pp 440-453.
Mallik Kotamarti, Douglas W. Raiford, M. L. Raymer, and Margaret H. Dunham, “A Data Mining Approach to Predicting Phylum for
Microbial Organisms Using Genome-Wide Sequence Data,” Proceedings of the IEEE Ninth International Conference on Bioinformatics and
Bioengineering, pp 161-167, June 22-24 2009.
Yu Meng and Margaret H. Dunham, “Efficient Mining of Emerging Events in a Dynamic Spatiotemporal,” Proceedings of the IEEE PAKDD
Conference, April 2006, Singapore. (Also in Lecture Notes in Computer Science, Vol 3918, 2006, Springer Berlin/Heidelberg, pp 750-754.)
Yu Meng and Margaret H. Dunham, “Mining Developing Trends of Dynamic Spatiotemporal Data Streams,” Journal of Computers, Vol 1, No
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