Alt-BEAM Archive

Message #00741



To: Noam Rudnick rudnick1@cwix.com, beam beam@corp.sgi.com
From: Sean Rigter rigter@cafe.net
Date: Sun, 21 Feb 1999 12:49:25 -0800
Subject: [alt-beam] Re: associative memories


Hi Noam,

It's Wilf , Sean is my oldest (1 of 5) offspring who is kind enough to
let me use his fast internet access computer while I'm home.

The question is : what is the question? Memory of what?
Do you mean memory of a sequence of steps? Or a sequence of external
inputs? Or an internal landscape representing a history of collisions vs
steps. Can't be deterministic linear sequence so needs pattern
recognition (associative memory) The walker can traverse it's internal
landscape,(acting out it's memory) sampled alternately with the real
world, and ?

The latter may be interesting since it would provide a learning mode.

Noam Rudnick wrote:
>
> Hello Wilf or Sean, by the way, which one is it?
>
> Your LIFE ideas sound interesting. I was more interested in the memory
> aspects of content addressable memory/associative neural nets.
> Specifically, do you have any ideas on how memories could be stored? I can
> only think of hardwiring them, which feels to unnatural. Also, I know it
> would be possible to store at least one desired memory, but would it be
> possible to change other stable memories without changing the first one?
>
> Thanks,
> Noam
>
> P.S. Maybe sometime we (and anyone else thats intersted) should go into
> the beam chatroom and actually talk about these ideas instead of sending
> e-mails back and forth.
> ----------
> > From: Sean Rigter
> > To: Noam Rudnick ; beam
> > Subject: Re: associative memories
> > Date: Sunday, February 21, 1999 12:00 AM
> >
> >
> > > Noam Rudnick wrote:
> > >
> > > oops, i guess i jumped the gun.
> >
> > No, I was just slow!
> >
> > In fact, if in your circuit you use 74HC14 gates with 2 identical
> > resistors connected together at one end and connected to the input of
> > each gate it forms 2 input "majority logic gates". If the voltage at the
> > other end of each of the 2 resistors is connected to input voltages the
> > output changes only if the majority of inputs is either one or zero. ie
> > 0V at both inputs change the output to 1 If both inputs are 1 the output
> > is 0 if there is no majority of one or zeroes at the 2 inputs, the
> > output remains unchanged.
> >
> > Actually one correction (my fingers are faster than my brain!)
> > I should have said the minimum neighborhood size for LIFE is 9 cells
> > with 8 surrounding the central cell. In large arrays each cell is
> > surrounded by 8 neighbors except at the edge of the array.
> >
> > XXX
> > X0X
> > XXX
> >
> > With non inverting majority logic gates the CA behaviour will be one
> > called "VOTE". Cells turn on if a majority of neighboring cells are on
> > or turn off when the majority are off. If there is no clear majority the
> > cell output remains unchanged.
> >
> > Such a rule could also be used to control group behaviour of robots if
> > they are wired up with majority logic rules and can communicate with
> > each other.
> >
> > Talk about peer pressure and conformity
> >
> > Anyway I wrote a short article on this which you can find on my
> > absolutely unfinished web page
> >
> > http://www.geocities.com/ResearchTriangle/System/8222/beamlife.html

--
Hey, come visit my homepage at
http://www.geocities.com/Area51/Nebula/1710/
Southpark, Mechwarrior2, V&V, Al-Qadim, and Milla Jovovich!

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