PottsICA

Annealed Neural Dynamics for
Independent Component Analysis
Jiann-Ming Wu
Department of Applied Mathematics
National Donghwa University
Intelligent Numerical Computation
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Outlines
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Blind source separation
Independent component analysis
Previous works, JadeICA, fastICA
ICA using Potts models, PottsICA
A comparison on the three methods
Conclusions and future works
Intelligent Numerical Computation
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Blind Source Separation (BSS)
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Sources
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Unknown
Mixing
Structure
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Observations
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BSS by PottsICA
IEEE Trans. On Neural Networks(2001)
PottsICA
Observations
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Blind source separation:
voice-music
BSS for voice-music separation
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BSS by ICA
ICA
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Blind Source separation : Fetal
EKG
ICA
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Previous works
FastICA:Helsinki University of Technology
JadeICA:by JF Cardoso
InformaxICA: Salk Institute
The others…
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The ICA problem
Unknown mixing structure:
Unkown statistical independent sources: S=
Observations:
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The goal of ICA
Recover independent sources by
such that
The joint distribution is as close as possible to the product of
the marginal distributions
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The unmixing problem
or
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Then
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Partition the range of each output component
…
…
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Non-overlapping projection
the active state is
where
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Internal representations
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Output component i
Bin or state number
…
1
2
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k… K-1 K
Membership vector
=[0
0 0 0 …
1…0 0]
the kth bit
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A mathematical programming
for non-overlapping projection
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Statistical mechanism
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Normalized histogram
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Discrete marginal entropy
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A mathematical programming for ICA
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Energy function for ICA
To minimize L is to solve a mixed integer and linear programming
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Annealed neural dynamics
Boltzmann distribution
Use mean field equations to find the mean configuration at each
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Derivation of mean field equations
Free energy by
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Mean field equations
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A hybrid of mean field annealing and
gradient descent method
MFE
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A hybrid of mean field annealing and
gradient descent method
Gradient descent method
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The PottsICA algorithm
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Numerical simulations
Artificial problem I
Independent
sources
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Numerical simulations
The normalized histogram of the five sources
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Numerical simulations
The mixed signals of the five sources using
a randomly generated mixing matrix
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Performance evaluations by Amari
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Performance evaluations
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Recovered signals by PottsICA
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Numerical simulations
The normalized histograms of the eight sources
Gaussian
Sub-Gaussian
Super-Gaussian
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Performance evaluations
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Performance evaluations
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Conclusions and Future works
1. Apply Potts encoding to ICA
2. PottsICA is better than JadeICA and FastICA
3. PottsICA is of collective decisions, PDP
4. PottsICA is potential for real world applications
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