Computational Metabolism on the Connection Machine and Other Stories...

[Marek Lugowski]

     Indiana University Computer Science Departamental Colloquium

   Computational Metabolism on a Connection Machine and Other Stories...
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	   Elisabeth M. Freeman, Eric T. Freeman & Marek W. Lugowski
	    graduate students, Computer Science Department
			  Indiana University

		Wednesday, 31 January 1990, 7:30 p.m.
			Ballantine Hall 228
	   Indiana University campus, Bloomington, Indiana


This is work in progress, to be shown at the Artificial Life Workshop II,
Santa Fe, February 5-9, 1990.  Connection Machine (CM) is a supercomputer
for massive parallelism. Computational Metabolism (ComMet) is such computation.
ComMet is a tiling where tiles swap places with neighbors or change their
state when noticing their neighbors.  ComMet is a programmable digital liquid.

Reference: Artificial Life, C. Langton, ed., "Computational Metabolism:
   Towards Biological Geometries for Computing", M. Lugowski, pp. 343-368,
   Addison-Wesley, Reading, MA: 1989, ISBN 0-201-09356-1/paperbound.
		
Emergent mosaics:
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This class of ComMet instances arise from generalizing the known
ComMet solution of Dijkstra's Dutch Flag problem.  This has implications
for cryptology and noise-resistant data encodings.  We observed deterministic
and indeterministic behavior intertwined, apparently a function of geometry.

A preliminary computational theory of metaphor:
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We are working on a theory of metaphor as transformations within ComMet.
Metaphor is loosely defined as expressing one entity in terms of another,
and so it must underlie categorization and perception.  We postulate that
well-defined elementary events capable of spawning an emergent computation
are needed to encode the process of metaphor.  We use ComMet to effect this.

A generalization of Prisoner's Dilemma (PD) for computational ethics:
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The emergence of cooperation in iterated PD interactions is known.
We propose a further generalization of PD into a communication between two
potentially complex but not necessarily aware of each other agents.  These
agents are expressed as initial configurations of ComMet spatially arranged
to allow communication through tile propagation and tile state change.

Connection Machine (CM) implementation:
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We will show a video animation of our results, obtained on a 16k-processor CM,
including emergent mosaics, thus confirmed after we predicted them
theoretically.  Our CM program computes in 3 minutes what took 7 days to do on
a Lisp Machine.  Our output is a 128x128 color pixel map.  Our code will
run in virtual mode, if need be, with up to 32 ComMet tiles per CM processor,
yielding a 2M-tile tiling (over 2 million tiles) on a 64k-processor CM.