[comp.simulation] SIMULATION DIGEST V12 N1

simulation@uflorida.cis.ufl.edu (Moderator: Paul Fishwick) (10/28/89)

Volume: 12, Issue: 1, Fri Oct 27 14:35:44 EDT 1989

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| TODAY'S TOPICS |
+----------------+

(1) AI & Simulation Conference: Methodology and Concepts
(2) Random Number Generation
(3) Virtual Reality/Space
(4) Hardware Support for List Processing

* Moderator: Paul Fishwick, Univ. of Florida
* Send topical mail to: simulation@bikini.cis.ufl.edu OR
  post to comp.simulation via USENET
* Archives available via FTP to bikini.cis.ufl.edu, login as
  'ftp', use your last name as the password, change
  directory to pub/simdigest.
* Simulation Tools available by doing above and changing the
  directory to pub/simdigest/tools.



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To: comp-simulation@ufl.edu
Path: uflorida!fish.cis.ufl.edu!fishwick
From: fishwick@fish.cis.ufl.edu (Paul Fishwick)
Newsgroups: comp.ai,comp.ai.digest,comp.simulation,alt.cyb-sys,comp.theory.dynamic-sys
Subject: AI and Simulation Conference
Date: 27 Oct 89 18:28:33 GMT
Sender: news@bikini.cis.ufl.edu
Reply-To: fishwick@fish.cis.ufl.edu ()
Organization: UF CIS Department



                  CALL FOR ABSTRACTS (DUE DATE: November 30)

                *** ARTIFICIAL INTELLIGENCE AND SIMULATION ***
                           ***  CONFERENCE ***
                  *** GROUP: Methodology and Concepts ***
                   Chair: Paul Fishwick, Univ. of Florida

                Part of the 1990 SCS Eastern Multi-Conference
                            Date: April 23-27
                       Place: Nashville, Tennessee


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We are currently seeking A) abstracts and B) suggestions for chaired
sessions for the track: Methodology and Concepts ---as part of the
upcoming Eastern Multi-Conference sponsored by the Society for
Computer Simulation. The group "Methodology and Concepts" focuses
on the conceptual foundations for simulation and system modeling
and relationships to AI concepts and theory. Topics include
(but are not limited to):

 1. Qualitative Methods in Simulation Modeling
 2. Integrating System Structure and Function
 3. Model Evolution and Engineering
 4. Analogy in System Models
 5. Natural Language Interfaces and Models for Systems
 6. Theory of Simulation Modeling and Analysis
 7. Causal Graph and Logic-Based Modeling for Dynamical Systems
 8. Knowledge-Based Approaches to Simulation
 9. Neural Network Modeling in Simulation
 10. Expert Systems Approaches to Simulation

Note the following deadlines: Abstracts to be sent by November 30th to:

 Society for Computer Simulation            (street address for express mail)
 Attn: AI Conference/M&C Group/ESC 90       
 P.O. Box 17900                             4838 Ronson Court, Suite L
 San Diego, CA. 92117                       San Diego, CA. 92111
                                            Phone: (619)-277-3888

Authors of accepted abstracts will be notified by SCS, and the author(s)
will receive author kits. Final papers must be submitted to SCS by
January 28th, 1990. Note that this is an extension of a previously
announced date. Please contact SCS for further information about this
group or the conference in general.

-paul fishwick

+------------------------------------------------------------------------+
| Prof. Paul A. Fishwick.... INTERNET: fishwick@bikini.cis.ufl.edu       |
| Dept. of Computer Science. UUCP: gatech!uflorida!fishwick              |
| Univ. of Florida.......... PHONE: (904)-335-8036                       |
| Bldg. CSE, Room 301....... FAX is available                            |
| Gainesville, FL 32611.....                                             |
+------------------------------------------------------------------------+


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To: Gary Morris <garym@crash.cts.com>
Cc: comp-simulation@ucsd.edu, garym@telesoft.com, ddavis@DINO.BBN.COM
In-Reply-To: Your message of Thu, 19 Oct 00 19:89:23 +0000.
Date: Tue, 24 Oct 89 15:25:29 -0400
From: kanderso@DINO.BBN.COM

  To: comp-simulation@ucsd.edu
  Date: Thu Oct 19 16:57:23 1989
  From: garym@crash.cts.com (Gary Morris)
  
  
  First I need the generator to give numbers that are uniformly distributed
  over the full range (which should be a minimum of 16 bits, ie:
  -32768..32767, but preferably 32 bits).  It should also have a very long
  period as it will be used tens of millions of times during the simulation. 
  The random function (random (3)) on our Unix system (Sun 4.0) sounds good
  according to the manual page but there is not much info on the
  implementation nor are references provided. 
  
Here are some paper's on portable random number generataors.  The
first is the most recent, and probably the most useful.

Pierre L'Ecuyer, Efficient and Portable Combined Random Number Generators,
CACM, June 1988, Vol 31, Number 6, p. 742-774.

S.K. Park and K.W. Miller, Random number generators:  good ones are hard to find,
  CACM, v31, 10, Oct. 1988, p. 1192 - 1201.
Linus Schrage, A More Portable Fortran Random Number Generator,
  ACM Trans. Math. Soft., V5, No. 2, p 132-138, 1979.

  The man page says:
  > DESCRIPTION
  >      random uses a non-linear  additive  feedback  random  number
  >      generator employing a default table of size 31 long integers
  >      to return successive pseudo-random numbers in the range from
  >      0  to (2**31)-1.  The period of this random number generator
  >      is very large, approximately 16*((2**31)-1).
  
  Second, I want to be able to simulate a selection.  I'm not sure if I need a
  special RNG for this or if I can filter a uniformly distributed RNG to get a
  weighted distribution.  Consider a simulation of someone inserting the cut
  card into the middle of a deck of cards.  Assume the person is attempting to
  insert the card into the middle of the deck.  If I were to use a random
  number to pick the insertion point, it would be evenly distributed over the
  range 1..52.  In reality, the distribution should be heavily weighted to the
  center of the deck with the frequency of occurrence dropping away from the
  center, since someone trying to insert in the center will usually get pretty
  close and rarely insert near the edge.  Hear's a graph that attempts to show
  what I'm trying to do (vertical axis is frequency of occurrence, horizontal
  is the position within the deck or random value):
  
  	|                 |       |       _       |
  Freq:	|                 |       |      / \      |
  	|                 |       |     /   \     |
  	|-----------------|       |    /     \    |
  	|                 |       |   /       \   |
  	|                 |       |  /         \  |
          +-----------------+       +---------------+
  Value:   1      26       52        1      26      52
  	uniform distribution      weighted to center
  
  
See the book Numerical Recipes, by Press and others for ways to do
this for arbitray distributions such as yours.  Here is the LISP i use
for gaussian random numbers.

(defun gaussian-random-1 ()
  "Returns a gaussian random variable with mean 0.0 and standard deviation 1.0.
Good tails."
  (* (sqrt (* -2.0 (log (random 1.0))))
     (sin (* #.(* 2.0 (coerce pi 'single-float)) (random 1.0)))))




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To: comp-simulation@ames.arc.nasa.gov
Path: milton!simstim
From: simstim@milton.u.washington.edu (simstim)
Newsgroups: comp.simulation
Subject: Virtual Reality/ Space
Keywords: cyberspace
Date: 27 Oct 89 04:34:01 GMT
Organization: Univ of Washington, Seattle


I am trying to find information on the subject of Virtual Reality/Space.
If you know of any publications, papers, ftp sites, etc..., please Email 
me directly. I will summarize the responses.

Thank you for assistance.


						- Steve

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"There are two major products that come out of Berkeley: LSD and UNIX. We
 don't believe this to be a coincidence." ||   - Jeremy S. Anderson 

#include <disclaimer.h>                   simstim@milton.u.washington.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


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To: watmath!comp-simulation@watmath.waterloo.edu
Path: ccng!sareibi
From: sareibi@ccng.waterloo.edu (Shawki M. Areibi)
Newsgroups: comp.simulation
Subject: Hardware support for list processing
Date: 25 Oct 89 15:10:13 GMT
Distribution: comp
Organization: Electrical Engineering Dept., University of Waterloo


I am designing a hardware support for Time Warp distributed simulation
I was wondering if there is any reference to list processors for
distributed simulation.
One reference I found was a paper by Meir Barel at Aachen Tech Univ in
w. Germany. I would appreciate it if someone could tell me about other
references concerning this subject, as it is of great importance to my
thesis work.

you can email me at     sareibi@ccng.waterloo.edu



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