Post by Moderator: Paul Fishwi » Sat, 25 Jul 1992 00:00:28

Volume: 28, Issue: 7, Thu Jul 23 10:59:05 EDT 1992


  ACM Transactions on Modeling & Computer Simulation
  Simulation of the Universe
  Queuing Analysis
  GNANS Dynamical Systems Software
  Simulation Kit
  Genetic Algorithms

* Moderator: Paul Fishwick, Univ. of Florida
* Send topical mail to: OR
  post to comp.simulation via USENET
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From Thu Jul 16 11:14:31 1992
Date: Thu, 16 Jul 92 11:10:22 EDT
From: Sandra Griffith - SRC <>
Subject: for electronic version of Simulation Digest

Table of Contents for issues of the ACM Transactions of Modeling and
Computer Simulation (TOMACS):

Volume I, Issue 1:  January 1991
(actually distributed in April 1991)

1.  Analysis of Parallel, Replicated Simulations Under a
    Completion Time Constraint (Peter W. Glynn and Philip
2.  A Study of Time Warp Rollback Mechanisms (Yi-Bing Lin
    and Edward D. Lazowska)
3.  Performance Bounds on Parallel Self-Initiating Discrete
    Event Simulations (David M. Nicol)
4.  A Time-Division Algorithm for Parallel Simulation
    (Yi-Bing Lin and Edward D. Lazowska)

Volume I, Issue 2:  April 1991
(actually distributed in November 1991)

1.  Simulation, Technology, and the Decision Process (Philip J.
    Kiviat) [Keynote address to Winter Simulation Conference 1990]
2.  Efficient and Portable Combined Tausworthe Random Number
    Generators (Shu Tezuka and Pierre L'Ecuyer)
3.  The Hierarchical Simulation Language (HSL):  A Versatile Tool
    for Process-Oriented Simulation (D.P. Sanderson, R. Sharma,
    R. Rozin, and S. Treu)
4.  An Analysis of Rollback-Based Simulation (Boris Lubachevsky,
    Alan Weiss, and Adam Shwartz)

Volume I, Issue 3:  July 1991
(actually distributed in June 1992)

1.  Mechanisms for User Invoked Retraction of Events in Time Warp
    (Greg Lomow, Samir R. Das, and Richard M. Fujimoto)
2.  Model Base Management for Multifacetted Systems (Bernard P.
    Zeigler, Cheng-Jye Luh, and Tag-Gon Kim)
3.  Asynchronous Algorithms for the Parallel Simulation of Event-
    Driven Dynamical Systems (Vijay K. Madisetti, Jean C. Walrand,
    and David G. Messerschmitt)
4.  Book Review of Thomas J. Schriber's An Introduction to Simulation
    Using GPSS/H (Tuncer Oren)

Volume I, Issue 4:  October 1991
Special Issue:  Parallel and Distributed Simulation Performance
                Ian Akyildiz and Richard M. Fujimoto, Eds.
(in press)

1.  Optimal Memory Management for Time Warp Parallel Simulation
    (Yi-Bing Lin and Bruno R. Preiss)
2.  An Evaluation of the Chandy-Misra-Bryant Algorithm for Digital
    Logic Simulation (Larry Soule and Anoop Gupta)
3.  A Unifying Framework for Distributed Simulation (R. Bagrodia,
    Wen-Toh Liao, and K.M. Chandy)
4.  Bounds and Approximations for Self-Initiating Distributed
    Simulation Without Lookahead (Robert E. Felderman and Leonard

Volume II, Issue 1:  January 1992
(in press)

1.  Synchronization Mechanisms for Distributed Event-Driven
    Computation (Vijay K. Madisetti and David Hardaker)
2.  A New Inversive Congruential Pseudorandom Number Generator
    with Power of Two Modulus (Jurgen Eichenauer-Herrman and
    Holger Grothe)
3.  Structural and Behavioral Equivalence of Simulation Models
    (Lee Schruben and Enver Yucesan)
4.  A Multimodel Methodology for Qualitative Model Engineering
    (Paul A. Fishwick and Bernard P. Zeigler)




Newsgroups: comp.simulation
Path: news
Subject: anyone has a universe-property simulator?
Sender: (News system)
Organization: Tufts University
Distribution: usa
Date: Sat, 18 Jul 1992 22:51:41 GMT

    Here's my idea (I want to know if anyone has heard of such a
package). I've seen a software package called "planetary simulator" or
some such thing, the idea being that you enter some initial data about
the basic constants (planet size, distance to start, star type, etc.)
and then the program uses that in physics models to tell you about the
kind of planet you'd have (weather, geology, etc.).
    Has anyone tried doing the same thing for the large-scale
structure of the universe? That is, have a program which implements
the latest cosmological models, where you give it the basic
fundamental constants of the universe (relative strengths of the
forces, relative sizes of various particles, etc.) and it uses them to
predict what kind of universe you'd then have (i.e., would elements
form, would stars form, would it expand, would it cycle, etc.)? Seems
to me like this would be a great educational tool, as well as
something that could be used to test some of the Anthropic Principle
claims (we may get some unexpected results, if we tweak more than one
fundamental constant!). Any takers, among the physicists who know
enough to do such a thing?

Mike Levin (please reply to


Newsgroups: comp.simulation
Path: news
From: (Mitra Mousumi)
Subject: Help with a paper
Sender: (USENET Network News)
Organization: NASA Langley Research Center, Hampton, VA  USA
Date: Mon, 20 Jul 1992 18:56:50 GMT

Recently I had mailed a query on Non-stationary queues. From one
response I located a paper:

"A Simple Approximation to the Average Queue Size in the Time-Dependent
           M/M/1 Queue" by Kenneth LLyod Rider.

I have a few clarifications to make about the paper. However, when
I tried to locate the author at the address given in the paper, nobody
there could tell me anything about him. I would appreciate any help in
either locating the author or if anyone else has read the paper, I would
like to discuss my questions with them.

Thank you,
Mousumi Mitra


Subject: [SOFTWARE]


Date: Mon, 20 Jul 92 13:55:07 -0400
From: "Paul Fishwick" <>
Subject: Gnans

[[ED: Forwarded from group comp.theory.dynamic-sys -PAF]]

From: (Bengt Martensson)
Newsgroups: comp.theory.dynamic-sys
Subject: Announcing Gnans 1.0 Beta
Date: 17 Jul 92 15:12:31 GMT
Sender: (NEWS-Service)
Organization: University of Bremen, Germany
Nntp-Posting-Host: athena

                      ANNOUNCING GNANS 1.0 BETA

Gnans, a free program for stochastic and deterministic dynamical
systems, is ready in beta test version.

Gnans is a program (and language) for the numerical study of
deterministic and stochastic dynamical systems. The dynamical systems
may evolve in continuous or discrete time. It has an intuitive
Graphical User Interface using the X Window System. It has been ported
to Sun4 and Sun3, Silicon Graphics, and IBM RS6000 (the latter two do
not have dynamic loading implemented, though).

Gnans loads a ``system'', a definition of a dynamical system in a
special, equation oriented, language. The description consists of
declarations of states etc, and equations describing the dynamics of
the system. As an advanced feature, arbitrary C++-code may also be
contained in the system description. Gnans sorts the equations and
translates the system and is then able to solve the system equations
numerically with the speed of a compiled (as opposite to interpreted)
program.  Several numerical integrators, also for stochastic (Ito-)
differential equations, are provided. Gnans has an intuitive user
interface, making it possible to control the program and to change all
relevant parameters using an intuitive point-and-click interface. In
this operation, it can be considered ``an initial value problem (IVP)
engine''. Using a simple script language, this IVP-engine can be
programmed. As a by-product, this offers the possibility of a tty
interface. (Actually, as another by-product, Gnans contains a rather
powerful pocket calculator!)  Interactive plotting program can be run
as child processes, with the possibility to define commands to be sent
by the press of a button to the interactive plotting program.

Gnans 1.0 is copyrighted, but freely distributable under the Gnu
General Public License.

An ANSI C compiler is required (even if you just get the binaries),
and C++ desirable. Gcc version 2.2.2 is fine, and free. Requires
X11 Release 4 or 5.  For compiling the sources Flex and the Athena
widgets are required. The program has been tested on Sun3 and Sun4's,
operating system SunOS 4.1.1 and 4.1.2, with MIT X11R5 and OpenWindows
3, with gcc 2.2.x; on Silicon Graphics X11R4 with gcc 2.2.2; on AIX
with the native C compile (xlc) and X11R5.

You can get Gnans by anonymous ftp to
( for those of you without nameserver). (Username
``ftp'', use your email address as password.) You can get either the
sources (recommended) or Sparc binaries. No distribution by other
media, at least not now.  Please also drop me an email, and tell me
about your success with the installation, and any bugs you encounter.

Please note: this is a new program, and has probably still a number of
bugs.  You have been warned. Also, neither support nor guarantee of
any kind is included in the price. I expect everyone who picks up the
program to REPORT BUGS, preferably with fixes. If you don't want to
contribute in this way, or if you want ``support'', please buy ACSL,
Simnon, or Simulab instead.

Volunteerers to port Gnans to other platforms (modern Unix, C++, X)
are also solicited. I also would be very happy for contributed

Bengt Martensson                                +49 421 218-2952 (office)
Institute for Dynamical Systems                 +49 421 17 17 13 (home)
University of Bremen                            +49 421 218-4235 (fax)
P.O. Box 330 440, D-2800 Bremen 33, Germany


Date: Thu, 16 Jul 92 23:08:11 MDT
From: doberman! (Mike Panzitta)
Reply-To: doberman!!doberman!
Subject: New Product Announcement

Doberman Systems
2027 East Ashley Ridge Road
Sandy, Utah   84092-7260

  Mike Panzitta
  801 944-4329


Simulation Kit Brings Continuous Simulation to the NeXT

SAN FRANCISCO, July 21, 1992-Doberman Systems today
announced the Simulation Kit, the first collection of
objects specifically developed for continuous system
modeling and simulation on the NeXT computer.  Coupled
with the NeXTSTEP application development
environment, the Simulation Kit provides the ideal
context for developing and analyzing object-oriented
simulations.  Unlike traditional methods, where the
model to be simulated is programmed procedurally from
derived equations, the object-oriented approach is
implemented directly from a block diagram
representation of the system.

Both academic and commercial users will find the
Simulation Kit to be a powerful yet easy-to-use tool for
modeling, analyzing, and teaching linear and nonlinear
continuous systems, numerical integration, and the
numerical solution of differential equations.  Typical
application areas are numerical analysis, engineering
systems (e.g. mechanical, electrical, thermodynamic,
and chemical), and control systems.  

The Simulation Kit includes Objective-C objects such as
processes, composite processes, simulations,
signals, and clocks.  Simulations are modeled by
connecting processes together with signals.  More
complex subsystems can be grouped together into
composite processes, which may then be manipulated and
used as a single process.  Commonly used processes such as
summers, gains, limiters, and Euler integrations are
included with source code; users can develop their own
processes by subclassing and using the provided sources
and documentation as a guide.

A typical use of the Simulation Kit can be illustrated by
simulating the motion of an automobile.  The car's
acceleration is determined by the pressure applied to
the accelerator by the driver, the slope of the road
(which depends on the location of the car), and the car's
drag (which increases with the vehicle's speed).  It is
known that the car's location and speed may be obtained by
successively integrating its acceleration.  From this
information, a block diagram composed of integrator,
gain, and summer blocks can be easily assembled.  These
process blocks and the signals that connect them are
implemented by Simulation Kit objects which are
organized in the same fashion as the block diagram.

Information such as the car's position, velocity, and
acceleration may then be output as the car "moves"
through its virtual environment.  This approach to
modeling provides greater insight and intuition into
the behavior of the system and allows simple and rapid
modification of the simulation.

The Simulation Kit employs several advanced features
that are unavailable in other simulation packages.

Multiple clocks allow simulations to contain "fast" and
"slow" subsystems.  Process prioritization permits
fine control over the execution of the simulation for
techniques such as cascaded integrations.

The Simulation Kit will be available in September 1992
for an estimated price of US$399 (US$99 academic).

Objects, full documentation, and example source code
will be distributed on NeXT-compatible floppy disks.

Technical support will be available by telephone or
electronic mail from Doberman Systems

Doberman Systems was launched in 1992 to develop
hardware and software solutions for the NeXT series of
professional workstations.  The firm is committed to
providing the highest quality products and services for
NeXT users and developers worldwide.

Doberman Systems, the Doberman logo, and Simulation Kit
are trademarks of Doberman Systems.  NeXT and NeXTSTEP
are trademarks of NeXT Computer, Inc.  All other
trademarks mentioned belong to their respective
 ---End included file---
Mike Panzitta
Doberman Systems                                                        Member
doberman!                 Salt Lake NeXT User's Group (SLNUG)




From: <>
        ga-l...@AIC.NRL.NAVY.MIL, Connectioni...@CS.CMU.EDU,
Subject: Fifth International Conference on Genetic Algorithms
Date: Fri, 17 Jul 92 11:39:30 CDT

                    Fifth International Conference
                        on Genetic Algorithms


                           17-22 July, 1993
                      University of Illinois at

                       PRELIMINARY ANNOUNCEMENT

The Fifth International Conference on Genetic Algorithms (ICGA-93),
will be held July 17-22, 1993 at the University of Illinois at
Urbana-Champaign.  This meeting brings together an international
community of researchers and practitioners from academia and
industry interested in algorithms suggested by the processes of
natural evolution. Topics of interest will include the design, analysis,
and application of genetic algorithms in optimization and machine learning.  
Machine learning architectures of interest include classifier systems and
connectionist schemes that use genetic algorithms.
Papers discussing how genetic algorithms are related to evolving system
modeling (e.g., modeling of nervous system evolution, computational ethology,
artificial life, economics, etc.) are also encouraged.

A formal call for papers for ICGA-93 will be released in the coming weeks.
In the meanwhile, for further information contact one of the conference
Dave Schaffer ((914) 945-6168, or
Dave Goldberg ((217) 333-0897, or
the publicity chair,
Rob Smith ((205) 348-1618,





Volume: 28, Issue: 10, Mon Feb 27 16:03:24 EST 1995


* Moderator: Paul Fishwick, Univ. of Florida

  post to comp.simulation via USENET
* Archives available via FTP to (
  Login as 'anonymous', use your e-mail address as the password, change
  directory to pub/simdigest. Do 'binary' before any file transfers.
* Simulation Tools available by doing above and changing the
  directory to pub/simdigest/tools.



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