Sheng Yu UM Statistics. Outline Motivation Strategy Sample Algorithms.
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Transcript of Sheng Yu UM Statistics. Outline Motivation Strategy Sample Algorithms.
A Strategy for Manifold Clustering with Sample Algorithms
Sheng YuUM Statistics
Outline
Motivation
Strategy
Sample Algorithms
Motivation (pattern)
Most current clustering methods are only able to detect agglomerated patterns.
New generation methods, such as normalized cut, have more flexibility, but are still not able to detect twisted, perhaps also entangled manifolds.
Such manifold patterns are not rare.
This is a manifold...
Example:
Try to cluster a pair of symmetric double spiral.
Example:
result fromk-means
Example:
result from normalized cut
Motivation (noise)
Theoretically, hierarchical clustering method using “single linkage” as the merging criterion is able to cluster twisted patterns. However, since “single linkage” is extremely sensitive to noisy, it is not actually a usable method.
MotivationTo design a new method that is not only able
to accomplish traditional “easy” tasks, but also handles twisted, entangled patterns as well.
Also, this new method should not be ruined by noise (moderate level, in terms of signal-noise ratio).
Outline
Motivation
Strategy
Sample Algorithms
Strategy (rationale)
Strategy (design)Engine: Searches
paths between each pair of points. More powerful engine provides faster speed.
Filter: Tells the engine which neighboring points can be connected from a specific start point. Controls the quality.
Engine
Filter
Example (easy one)
Example (not so easy one)
Example (not so easy one)
Example (hard one)
Outline
Motivation
Strategy
Sample Algorithms
Algorithms (filter)The filter I currently use is still primitive.
But it does a lot of jobs, such as the above examples.
The strategy is an open framework. We can build better filters to detect even more difficult patterns and have more resistance to noise.
Algorithmsthe importance of the engine
Sample Size 320
Sample Size 640
Brute force 97” Death touch
Fission 1.5” 65’’
Algebraic fission
Never minded 0.5”
Strategy (rationale)
AlgorithmsThe true benefit of a super fast engine is that
it allows us to do iteration.
We need to set up a range of acceptable number of clusters.
We do not need our initial parameters to be precise. The algorithm will do heuristic search for us.
a demo of visual aids for choosing parameters