NIPS-5 papers: Nonlinear dimensionallity reduction / Inverse kinematics

[David DeMers]

Non-Linear Dimensionality Reduction

David DeMers & Garrison Cottrell

ABSTRACT
--------
A method for creating a non--linear encoder--decoder for 
multidimensional data with compact representations is presented.  
The commonly used technique of autoassociation is extended to 
allow non--linear representations, and an objective function which
penalizes activations of individual hidden units is
shown to result in minimum dimensional encodings with
respect to allowable error in reconstruction.


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Global Regularization of Inverse Kinematics for Redundant Manipulators

David DeMers & Kenneth Kreutz-Delgado

ABSTRACT
--------
The inverse kinematics problem for redundant manipulators is
ill--posed and nonlinear.  There are two fundamentally different 
issues which result in the need for some form of regularization;
the existence of multiple solution branches (global ill--posedness) 
and the existence of excess degrees of freedom (local ill--posedness).
For certain classes of manipulators, learning methods applied to 
input--output data generated from the forward function can be used to
globally regularize the problem by partitioning the domain of the 
forward mapping into a finite set of regions over which the inverse 
problem is well--posed.  Local regularization can be accomplished
by an appropriate parameterization of the redundancy consistently over  
each region.  As a result, the ill--posed problem can be transformed 
into a finite set of well--posed problems.  Each can then be
solved separately to construct approximate direct inverse functions.

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Preprints are available from the neuroprose archive

Retrievable in the usual way:

unix> ftp archive.cis.ohio-state.edu (128.146.8.52)
login as "anonymous", password = <your-email-address>
ftp> cd pub/neuroprose
ftp> binary
ftp> get demers.nips92-nldr.ps.Z
ftp> get demers.nips92-robot.ps.Z
ftp> bye
unix> uncompress demers.*.ps.Z 
unix> lpr -s demers.nips92-nldr.ps.Z
unix> lpr -s demers.nips92-robot.ps.Z

(or however you print *LARGE* PostScript files)


These papers will appear in
S.J. Hanson, J.E. Moody & C.L. Giles, eds,
Advances in Neural Information Processing Systems 5
(Morgan Kaufmann, 1993).





Dave DeMers			 	        demers at cs.ucsd.edu
Computer Science & Engineering	0114		demers%cs at ucsd.bitnet
UC San Diego					...!ucsd!cs!demers
La Jolla, CA 92093-0114	(619) 534-0688, or -8187, FAX: (619) 534-7029