Newsgroups: comp.ai.neural-nets
Path: cantaloupe.srv.cs.cmu.edu!europa.chnt.gtegsc.com!news.kreonet.re.kr!news.dacom.co.kr!news.netins.net!solaris.cc.vt.edu!news.mathworks.com!gatech!howland.reston.ans.net!vixen.cso.uiuc.edu!uchinews!kimbark!gal2
From: gal2@kimbark.uchicago.edu (Jacob Galley)
Subject: Re: Fuzzy ARTMAP (Was Re: Requested ART2 Reference ...)
X-Nntp-Posting-Host: midway.uchicago.edu
Message-ID: <DFoEnJ.Ftx@midway.uchicago.edu>
Sender: news@midway.uchicago.edu (News Administrator)
Reply-To: gal2@midway.uchicago.edu
Organization: University of Chicago
References: <442a67$5r6@news.magi.com> <O> <DFMx3E.632@unx.sas.com>
Date: Fri, 29 Sep 1995 16:47:43 GMT
Lines: 32

saswss@hotellng.unx.sas.com (Warren Sarle) writes:
>
>   At the start of each input presentation the ART_a vigilance
>   parameter rho_a equals a baseline vigilance rho-bar_a. ... If
>      |x^ab| < rho_ab |y^b|
>   then rho_a is increased until it is slightly larger than ...
>
>That's all very well during training, but the expression above depends
>on the _target_ value via y^b. So what do you do during the _test_
>phase? Using target values during testing would be cheating.

Right.  There is no match tracking unless ART_b receives an input to
associate with the input to ART_a.  Match tracking is only used during
training (ie. when inputs are fed to both ARTs), to ensure that all
associations between ART_a and ART_b are resolved without error.
During testing, ART_b is not fed the "answer" as an input.  Instead it
resolves it through resonance with the inter-ART map field F^ab.  As
a result, the ARTMAP might make some mistakes during testing---as it
should be.

I think it is prudent to freeze the weights throughout the system
during testing, so that the categories in ART_a do not stray from the
learned associations with ART_b.  But I don't know the official word
on this.

I'd also like to know why Capt. Young changes the vigilance parameter
in ART_a during testing.

Jake.

-- 
Reinheitsgebot <-- "Keep your laws off my beer!" <-- gal2@midway.uchicago.edu
