Invariance, group representations and orientation estimation

[Reiner Lenz]

Problems involving the concept of invariance have received a lot of
attention and although the following papers are somewhat outside the
field of neural networks perhaps someone may find something intresting
in them. 

The main idea is that invariance is often closely related to groups
and there representations and that these in turn are closely related
to special transforms. The most important example is shift-invariance
which is related to the additive group which lead to the Fourier
transform. 

If you are interested you can find some of the reprints in

http://www.isy.liu.se/~reiner/proj_desc/section3_3.html

GROUPS: is an overview article

P2-invariance: Describes the application to permutation and projection
	invariance

Group Theoretical Transforms: uses the dihedral group

Lie-Matching: computes the orientation parameters from 3-D data and is
	an example of fast iterative matching algorithms based on the
	interplay between Lie-group and Lie-algebra.


As I said before: Not strictly NN but perhaps interesting to someone.

Best regards 

"Kleinphi macht auch Mist"

Reiner Lenz | Dept. EE.                 |
            | Linkoeping University	| email:	reiner at isy.liu.se
            | S-58183 Linkoeping/Sweden |