
Genetic Algorithms Digest   Friday, June 28 1991   Volume 5 : Issue 17

 - Send submissions to GA-List@AIC.NRL.NAVY.MIL
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Today's Topics:

	- ICGA'91 Schedule errata
	- TSP, editor's note in Volume 5 : Issue 11
	- Free GA code (C and Lisp)
	- Splicer software for genetic algorithms

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CALENDAR OF GA-RELATED ACTIVITIES: (with GA-List issue reference)

4th Intl. Conference on Genetic Algorithms (v5n9, v5n14)     Jul 13-16, 1991
AAAI 91, National Conference on AI, Anaheim, CA              Jul 14-19, 1991
EUROPEAN SUMMER SCHOOL on MACHINE LEARNING (v5n7)            Jul 22-31, 1991
Genetic Algorithm Course, Stanford (v5n11)                   Jul 22-26, 1991
IJCAI 91, International Joint Conference on AI, Sydney, AU   Aug 25-30, 1991
First European Conference on Artificial Life (v5n10)         Dec 11-13, 1991
ECAI 92, 10th European Conference on AI (v5n13)              Aug  3-7,  1992

(Send announcements of other activities to GA-List@aic.nrl.navy.mil)

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Date: Mon, 24 Jun 91 18:33:24 PDT
From: rik@cs.UCSD.EDU (Rik Belew)
Subject: ICGA'91 Schedule errata

    The TeX-to-ASCII filter (dvidoc) introduced a bunch of bugs in the
    version of the schedule that went out over Email, most of which we
    caught.  But it also performed an interesting and almost amusing form
    of semantic recombination on two papers to be presented in the first
    poster session.  In the original schedule the pseudo-paper:


	A  simulated annealing  like convergence  theory  for the  simple
	genetic algorithm: anomalous results and their explanation
	  Stephanie Forrest and Melanie Mitchell

    is actually the offspring of two real parent papers:

	A  simulated annealing  like convergence  theory  for the  simple
	genetic algorithm
	  Thomas E. Davis and  Jose C. Principe
	The performance of genetic algorithms on Walsh polynomials:
	anomalous results and their explanation
	  Stephanie Forrest and Melanie Mitchell

    Please assign very low fitness to the offspring and replace it
    with its parents in your copy.

    I apologize to the authors for the confusion and thank Tom Davis for
    bringing it to my attention.

	    Rik Belew

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From: mlidd@mwunix.mitre.org
Date: Mon, 24 Jun 91 08:58:14 EDT
Subject: editor's note in Volume 5 : Issue 11

    The talk's subject to which the editor is aluding is very simple.
    Basically I take issue with the "intuitively obvious" concept that genetic
    operators must be closed in the domain of interest.  By using an
    evaluation algorithm that uses all information in the (possibly illegal)
    domain, the GA search is expedited.  For example, an illegal traveling
    salesman problem (TSP) tour may be missing / duplicating some cities, and
    thus represent an illegal point in the problem domain, BUT it may contain
    a perfectly legal (and optimun?) sub-tour.  This is completely different
    from using penalty functions, which restrict consideration to small
    portions of the domain.  I believe that the illegal tours contain useful
    information.  Since the evalution function of a TSP tour having dupplicate
    cities, is greater than the optimum tour, (although the illegal tour may
    contain a perfectly good, optimum sub-tour) the implicit parallelism of
    the GA search can be used to direct the search to valid tours without
    resorting to penalty functions.  (Also, tours missing cities can easily be
    made complete to produce an estimate of their sub-tour "fitness".)

       I have applied this method to the TSP. I have solved 30 to 100 city
    TSPs as an initial test. I have produced optimal tour lengths using an
    unmodified version of GENESIS (two-point cross-over, mutation) with a
    simple chromosome coding (a list of N cities for a tour of length N).
    Convergence is quick for tours attempted so far (30-100 cities).  Research
    is continuing to determine 1st order schemata averages, etc. in order to
    substantiate the technique.  As in all new techniques, results are
    preliminary

    Please do not confuse this technique with penalty functions.  Penalty
    functions constrain the GA search.


    mark

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From: spears@AIC.NRL.Navy.Mil
Date: Mon, 24 Jun 91 11:27:25 EDT
Subject: Free GA code (C and Lisp)

    For those of you interested in obtaining some free GA software, I'm
    providing the packages I've been using for a few years. GAC is a GA
    written in C. GAL is my Common Lisp version.  They are similar in spirit
    to John Grefenstette's Genesis, but they don't have all the nice bells and
    whistles. Both versions currently run on Sun workstations. If you have
    something else, you might need to do a little modification. [ Alan Schultz
    informs me that GAL is easily ported to the Mac - although his version is
    no longer available.]

    In the spirit of "freeware", I am willing to e-mail either version (or
    both) to anyone who wants it. All I ask is that I be credited when it is
    appropriate. Also, I would appreciate hearing about improvements! This
    software is the property of the Department of the Navy.

    The code will be in a "shar" format that will be easy to install. This
    code is "as is", however.  There is a README and some documentation in the
    code.  There is NO user's guide, though (nor am I planning on writing one
    at this time). I am interested in hearing about bugs, but I may not get
    around to fixing them for a while. Also, I will be unable to answer many
    questions about the code, or about GAs in general. This is not due to a
    lack of interest, but due to a lack of free time!

    Bill Spears@aic.nrl.navy.mil

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From: ntm1169@dsac.dla.mil (Mott Given)
Date: Wed, 12 Jun 91 9:37:41 EDT
Subject: Splicer software for genetic algorithms

                                                                               
                                 SPLICER                                       
                           ORDERING INFORMATION                                
                                                                               
    **********************************************************************     
    *** Please note: You must be Government affiliated or a Contractor ***     
    ***              of the U.S. Govt. to receive software  from the   ***     
    ***              STB Help Desk.  Any other users wanting STB       ***     
    ***              software must purchase it through COSMIC which    ***     
    ***              can be reached at:                                ***     
    ***                          COSMIC                                ***     
    ***                          382 E. Broad St.                      ***     
    ***                          Athens, GA 30602                      ***     
    ***                          (404) 542-3265                        ***     
    **********************************************************************     
                                                                               
    1.  You must register with the STB Help Desk by sending the following      
        information along with the correct media!                              
                                                                               
           Name:                                                               
           Company or Govt. Organization:                                      
           Address:                                                            
           Address:                                                            
                                                                               
Johnson Space Center                                                           
SOFTWARE TECHNOLOGY BRANCH                                                     
                                                                               
COSMIC                                                                         
382 E. Broad St.                                                               
Athens, GA 30602                                                               
(404) 542-3265                                                                 
                                                                               
                                  SPLICER                                      
                                                                               
            A Genetic Algorithm Tool for Search and Optimization               
                                                                               
Splicer is a genetic algorithm tool that can be used to solve search and       
optimization problems. Splicer was created by the Software Technology          
Branch of the Information Systems Directorate at NASA/Johnson Space Center     
(JSC) with support from the MITRE Corporation. The key features of Splicer     
are:                                                                           
                                                                               
**Modular Architecture: Splicer 1.0 was developed using a modular              
   architecture that includes a Genetic Algorithm Kernel, interchangeable      
   Representation Libraries, Fitness Modules, and User Interface Libraries,    
   and well-defined interfaces between these components. This architecture     
   and well-defined interfaces between these components. This architecture     
   supports portability, flexibility, and extensibility, as described more     
   fully below.                                                                
                                                                               
**Portability: Splicer was developed using C, for portability and speed,       
   originally on an Apple Macintosh and has been subsequently ported to        
   UNIX workstations (Sun 3 and 4; IBM RS6000) using X Windows. The Genetic    
   Algorithm Kernel, Representation Libraries, and Fitness Modules are         
   completely portable. The X Window interface can be used on any              
   workstation supporting X 11 and the HP Widget Set (Xw; distributed free     
   with X11). Splicer comes with all source code.                              
                                                                               
**Genetic Algorithm Kernel: A genetic algorithm kernel was developed that      
   is independent of representation (i.e., problem encoding), fitness          
   function, or user interface type. The GA kernel comprises all functions     
   necessary for the manipulation of populations. These functions include      
   the creation of populations and population members, the iterative           
   population model, fitness scaling, parent selection and sampling, and       
   the generation of population statistics. In addition, miscellaneous         
   functions are included in the kernel (e.g., random number generators).      
                                                                               
**Representation Libraries: Different problem-encoding schemes and             
   functions are defined and stored in interchangeable representation          
   functions are defined and stored in interchangeable representation          
   libraries. This allows the GA kernel to be used for any representation      
   scheme. Al present, the Splicer tool provides representation libraries      
   for binary strings and for permutations. These libraries contain            
   functions for the definition, creation, and decoding of genetic             
   strings, as well as multiple crossover and mutation operators.              
   Furthermore, the Splicer tool defines the appropriate interfaces to         
   allow users to create new representation libraries.                         
                                                                               
**Fitness Modules: Fitness functions are defined and stored in                 
   interchangeable fitness modules. Fitness modules are the only component     
   of the Splicer system a user will normally be required to create or         
   alter to solve a particular problem. Within a fitness module, a user can    
   create a fitness (or scoring) function, SCl the initial values for          
   various Splicer control parameters (e.g., population size), create a        
   function which graphically displays the best solutions as they are          
   found, and provide descriptive information about the problem. The tool      
   comes with several example fitness modules.                                 
                                                                               
**User Interface Libraries: Splicer provides two user interface libraries:     
   a Macintosh user interface and an X Window System user interface These      
   user interfaces are event-driven and provide graphic output in windows.     
   (A character-based, menu-driven interface is also available, but is not     
   (A character-based, menu-driven interface is also available, but is not     
   fully supported.)                                                           
                                                                               
**Applications: Stand-alone Splicer applications can be used to solve          
   problems without any need for computer programming. Several examples are    
   provided. However, to create a Splicer application for a particular         
   problem, a Fitness Module must be created using the C programming           
   language. The process of developing a Fitness Module is fully discussed     
   in the accompanying documentation.                                          
                                                                               
**Fully Documented: Splicer comes with extensive documentation including a     
   Reference Manual and a User's Manual. An Architecture Manual and the        
   Advanced Programmer's Manual are being written.                             

**Availability: Splicer version 1.0 is currently available. Splicer is free    
   to NASA and its contractors for use on government projects by calling       
   the Software Technology Branch Help Desk between the hours of 9:00 AM to    
   4:00 PM (CST) Monday through Friday at (713) 280-2233.  Government          
   contractors should have their contract monitor call the Software            
   Technology Branch Help desk to obtain Splicer. Others may purchase          
   Splicer (including all documentation) from COSMIC at a nominal fee for      
   unlimited copies with no royalties. An electronic bulletin board            
   containing information regarding Splicer can be reached 24 hours a day      
   at (713) 280-3896 or (713) 280-3892. Communications information is 300,     
   1200, or 2400 baud, no Parity 8 data bits, and 1 stop bit.                  
                                                                               
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End of Genetic Algorithms Digest
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