papers available

[Melanie Mitchell]

The following papers are available via anonymous ftp:

		The Evolution of Emergent Computation 


		James P. Crutchfield   	    Melanie Mitchell    
        	    UC Berkeley            Santa Fe Institute        

                  Santa Fe Institute Working Paper 94-03-012

	     	              Submitted to Science
	   			  March, 1994

			  	  Abstract

	A simple evolutionary process can discover sophisticated methods
	for emergent information processing in decentralized spatially-extended
	systems.  The mechanisms underlying the resulting emergent computation
	are explicated by a novel technique for analyzing particle-based
	logic embedded in pattern-forming systems.  Understanding how 
	globally-coordinated computation can emerge in evolution is relevant
	both for the scientific understanding of natural information processing
	and for engineering new forms of parallel computing systems. 


To obtain an electronic copy of this paper (9 pages):

	ftp ftp.santafe.edu
	login: anonymous
	password: <your email address>
	cd /pub/Users/mm
	binary
	get EvEmComp.ps.Z
	quit

Then at your system:

	uncompress EvEmComp.ps.Z
	lpr -P<printer-name> EvEmComp.ps

If you cannot obtain an electronic copy, send a request for a hard copy to
pdb at santafe.edu.  


-----------------------------------------------

	A Genetic Algorithm Discovers Particle-Based Computation 
			in Cellular Automata

	Rajarshi Das		Melanie Mitchell	James P. Crutchfield
	Santa Fe Institute	Santa Fe Institute	UC Berkeley


	            Santa Fe Institute Working Paper 94-03-015

	Submitted to the Third Parallel Problem-Solving From Nature Conference
				March, 1994	

				Abstract
	How does evolution produce sophisticated emergent computation in
	systems composed of simple components limited to local interactions?
	To model such a process, we used a genetic algorithm (GA) to evolve 
	cellular automata to perform a computational task
	requiring globally-coordinated information processing.  On most runs a
	class of relatively unsophisticated strategies was evolved, but on a
	subset of runs a number of quite sophisticated strategies was
	discovered.  We analyze the emergent logic underlying these strategies
	in terms of information processing performed by ``particles'' in
	space-time, and we describe in detail the generational progression of
	the GA evolution of these strategies.  Our analysis is a preliminary
	step in understanding the general mechanisms by which sophisticated
	emergent computational capabilities can be automatically produced in
	decentralized multiprocessor systems.


To obtain an electronic copy of this paper (13 pages):

(The electronic version of this paper has been broken up into four parts
to facilitate printing.)

	ftp ftp.santafe.edu
	login: anonymous
	password: <your email address>
	cd /pub/Users/mm
	binary
	get GA-Particle.part1.ps.Z
	get GA-Particle.part2.ps.Z
	get GA-Particle.part3.ps.Z
	get GA-Particle.part4.ps.Z
	quit

Then at your system:

	uncompress GA-Particle.part1.ps.Z
	uncompress GA-Particle.part2.ps.Z
	uncompress GA-Particle.part3.ps.Z
	uncompress GA-Particle.part4.ps.Z
	lpr -P<printer-name> GA-Particle.part1.ps
	lpr -P<printer-name> GA-Particle.part2.ps
	lpr -P<printer-name> GA-Particle.part3.ps
	lpr -P<printer-name> GA-Particle.part4.ps

If you cannot obtain an electronic copy, send a request for a hard copy to
pdb at santafe.edu.