Volume 5: No. 13 

Honeywell has been awarded Patent 5,373,452 for using neural
networks to make an "intangible sensor," able to identify discrete
values of an intangible property of a substance. [Greg Aharonian
A $4 neuralnetwork chip called the RSC164 is available
from startup company Sensory Circuits Inc., 1735 N. First St.,
San Jose, CA 951124511; (408) 4521000, (408) 4521025 FAX.
[
"Most neural nets used for data analysis _are_ statistical
models. The exceptions work only with noisefree data,
such as ART clustering algorithms that do not yield statistically
consistent estimates with noisy data. Basic Kohonen networks
(not LVQ or SOM) are very similar to kmeans clustering. If the
activation of the output nodes is determined by Euclidean distance
rather than the more usual scalar product, then a Kohonen network
is really an alternative algorithm for kmeans clustering."
[Warren S. Sarle
"A simulation study comparing various Kohonen networks (in Neuralworks Professional II) with a kmeans clustering program (FASTCLUS in the SAS/STAT product) was done by P.V. Balakrishnan et al. "A study of the classification capabilities of neural networks using unsupervised learning," Psychometrika, 59, 509525 (1994). I recommend that neural net researchers read this article as an example of how to do simulations. The clustering program produced fewer classification errors than any of the Kohonen nets for all combinations of the number of clusters, the number of inputs, and the noise level. The error rate for the clustering program was sensitive to the amount of noise, as one would expect, but only slightly sensitive to the number of inputs (the more, the better) and not sensitive to the number of clusters. The error rates for the Kohonen nets were most sensitive to the number of clusters, with considerably less sensitivity to the number of inputs or the noise level (very strange!). Over all, the Kohonen nets made almost 10 times as many errors as the clustering program." [Ibid.] (I've edited Sarle's text to fit TCC's limited space.)
Neuron Digest is back after a 3month lapse. Send a
"subscribe" or "subscribe desired@net.address" subject line or
message to