🚀 go-pugleaf

Volume: 22, Issue: 3, Thu Jun 13 13:33:10 EDT 1991

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

(1) RE: Kalman Filters
(2) Fast Normal Random Variate Generation
(3) CALL: Fuzzy Control Workshop
(4) NEWSGROUP: Comp.Online
(5) WANTED: Synthetic Unix Workloads


* 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 (128.227.224.1).
  Login as 'ftp', use your last name as the password, change
  directory to pub/simdigest. Do 'type binary' before any file xfers.
* Simulation Tools available by doing above and changing the
  directory to pub/simdigest/tools. 



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Date: Thu,  6 Jun 1991 13:39:08 -0700 (PDT)
From: Terry Cline <terry@bird.clarity.com>
To: fishwick@fish.cis.ufl.edu
Subject:  Re: SIMULATION DIGEST V22 N2

To the person who asked about simulating Kalman filters and the GPS navigation
system:

The folks at The Analytic Sciences Corp. in Reading, MA do this sort of thing
for a living (among other things).  I haven't worked there for almost 10 yrs
so I don't even remember a phone number, but they should be easy to reach.
Try asking for Ray Nash who could refer you to where in their organization to 
go. 

Terry Cline
Clarity Software, Inc.
2700 Garcia Ave.
Mt. View, CA 94043
415-691-0320x250
tcline@clarity.com



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To: uunet!comp-simulation@uunet.UU.NET
Path: motcid!reilly
From: motcid!reilly@uunet.UU.NET  (Patrick L. Reilly)
Newsgroups: sci.math,sci.math.num-analysis,sci.math.stat,comp.simulation
Subject: Normal Variate Generator Error
Summary: error in normal variate generator
Keywords: normal variate generator errors
Date: 7 Jun 91 00:23:04 GMT
Reply-To: motcid!uunet.uu.net!motcid!reillyp@uunet.UU.NET
Distribution: sci
Organization: Motorola Inc., Cellular Infrastructure Div., Arlington Heights, IL       


I am interested in any information that might have appeared
in subsequent journal articles that describe the normal
variate generation method proposed in

"Computer Generation of Normal Random Variates"
A.J. Kinderman & J.G. Ramage
Journal of the American Statistical Asso.
Dec. 1976, vol. 71, Number 356


The article describes a very fast normal variate generator
that has been implemented. Unfortunately, the author's
choices of some of the constants used are not very intuitive
and some further discussion might exist elsewhere in the
literature.

More importantly, however, is a very subtle aberration in the
distribution generated by the algorithm. The subtlety is so
great that it is not noticeable until 100 million samples have been
generated and a histogram plot made. The user will then note a
bi-modal property centered around the mean.

We have been able to correct this by experimentation, but prefer
to have a better understanding of the method and to discover is
earlier experimenters have observed this problem and its correction
noted by the authors.

Please e-mail to me direct: reilly@motcid.rtsg.mot.com

I will post the results.

============================= `` '' ============================== 
Patrick Reilly, Ph.D.	     < @ @ >    tel: 1+708+632-3109
Motorola CIG/Switch Dev.      ( > )     fax: 1+708+632-2413
1501 W. Shure Dr.              \~/      UUNET: uunet!motcid!reilly
Mail Drop BC569/G194                    reilly@motcid.rtsg.mot.com
Arlington Hts., IL 60004

     REilly's CAutioNary Truth:  Any ill-formed premise may be
     --       --    -    -       modeled and validated with 
				 simulation.
================================================================== 



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

Date: Fri, 7 Jun 91 13:12:57 -0400
From: "Paul Fishwick" <fishwick@fish.cis.ufl.edu>
To: simulation@ufl.edu
Subject: CALL: Fuzzy Control Workshop

[[ED: Forwarded from comp.ai -PAF]]

>From uflorida!math.ufl.edu!eng.ufl.edu!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!rpi!uupsi!sunic!liuida!petek Fri Jun  7 13:11:39 EDT 1991
Article: 8996 of comp.ai
Path: uflorida!math.ufl.edu!eng.ufl.edu!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!rpi!uupsi!sunic!liuida!petek
From: petek@ida.liu.se (Peter Eklund)
Newsgroups: comp.ai
Subject: IJCAI workshop on fuzzy control, deadline July 1
Date: 6 Jun 91 10:01:39 GMT
Sender: news@ida.liu.se
Organization: CIS Dept, Univ of Linkoping, Sweden

************DEADLINE NOW JULY 1**********

                 ANNOUNCEMENT - CALL FOR PARTICIPATION
                       FUZZY CONTROL WORKSHOP

                    IJCAI-91, SYDNEY, AUSTRALIA
                          AUGUST 24, 1991


WORKSHOP COMMITTEE
   Prof. Dr H J Zimmermann, RWTH Aachen, Aachen
   Dr M Reinfrank, Siemens AG, Munich
   Prof. L A Zadeh, University of California at Berkeley
   Prof. M Sugeno, Tokyo Institute of Technology
   Dr D Driankov (Chairman), University of Linkoping

During the past several years fuzzy control has emerged as one of
the most active and fruitful research areas in the application of 
fuzzy set theory, especially in the realm of industrial processes 
which do not lend themselves to control by conventional methods.
Fuzzy control has appeared as a qualitative extension of classical
control theory and is very similar to AI knowledge representations 
in that both model the ``common sense'' knowledge of an experienced 
human operator. In essence the theory of fuzzy control provides for 
an algorithm which can convert the control knowledge of an operator 
into an automatic control strategy. In particular fuzzy control 
theory appears very useful when;

* linearity and time-invariance can not be assumed; the responses 
  to change in manipulated variables are non-linear and highly 
  sensitive in certain regions. There are significant transport 
  lags in the process and the process itself is subject to random 
  disturbances.

* it is difficult to derive differential/difference equations
  representing the process i.e. there is a lack of a well-posed 
  mathematical model. At the same time the ability of the exper-
  ienced operator to cope with such a process is recognized and 
  these operators can describe their knowledge of control actions 
  linguistically as a set of rules.

* the human understanding of the process and its conventional
  mathematical description are alien and this results in a lack of
  an effective man-machine interface.

However, despite of the indisputable success of the theory of
fuzzy control, there remain a number of issues which are consider-
ed to be its weak points  requiring further investigation and more 
solid treatments. It is these issues which will be the focus of 
the workshop;

* efficient systematic methods for knowledge acquisition. So far the
  process of transferring the operator's knowledge into a usable 
  knowledge base have been time consuming and non-trivial.

* conception and design of fuzzy control systems that have the 
  capacity to learn from experience, that is a combination of 
  techniques from both fuzzy logic and neural networks can improve 
  the learnability and adaptability of a fuzzy controller in a 
  changing environment.

* well-founded formal procedures for fuzzy controller design based 
  on fuzzy models of the process. The need for the development of
  fuzzy dynamic systems theory is urgent with its emphasis on the 
  modeling of the linguistic structure of the process which extends 
  in a qualitative way the fundamental notions of state, controll-
  ability and stability.

It is at this last juncture that the theory of fuzzy control and 
recent developments in qualitative reasoning in AI meet each other 
and can be cross-fertilized. However, these two approaches have 
developed independ- ently from one another and there has been almost 
no exchange of ideas between the two scientific communities. In 
control theory the terms fuzzy rule-based formalism can be likened 
to a qualitative input/output model whereas the AI approach is akin 
to a qualitative state-space description and performs the function 
of an internal representation of the process. Thus, the fuzzy control 
representation describes what an operator does rather than why he 
does it. The knowledge about the later can only come from the internal 
representation of the process i.e. its model. In this context the 
workshop will provide a framework within which the similarities and 
differences between the two approaches can be highlighted and 
discussed in depth.

Speakers will be by invitation. For participants, a short abstract 
of the author's experience in fuzzy control or qualitative reasoning 
should be delivered to the workshop secretary at the address below 
by 1 July, 1991.

Peter Eklund (Secretary/Organizer)
Department of Computer and Information Science
University of Linkoping
S-581 83 Linkoping, Sweden
tel. (+46) 13 281950
fax. (+46) 13 142231
pwe@ida.liu.se (internet)
pwe@seliuida (bitnet)


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

Date: Sun, 9 Jun 91 23:53:21 EDT
From: tale@cs.rpi.edu (David C Lawrence)
To: simulation@cis.ufl.edu
Subject: RFD:  comp.online

Newsgroups: news.announce.newgroups,news.groups,comp.society.futures,alt.privacy,comp.infosystems,comp.simulation,soc.net-people,sci.research,bionet.general,comp.groupware,sci.virtual-worlds
Path: rpi!bounce-back
>From: cyberoid@milton.u.washington.edu (Robert Jacobson)
Subject: RFD:  comp.online moderated
Followup-To: news.groups
Sender: tale@cs.rpi.edu
Nntp-Posting-Host: cs.rpi.edu
Organization: Human Interface Technology Lab, Univ. of Wash., Seattle
Date: 10 Jun 91 03:41:45 GMT
Approved: tale@rpi.edu

I would like to propose the creation of a new newsgroup, COMP.ONLINE
The purpose of this newsgroup would be to discuss the phenomena of being
"online" -- what it means to be part of an electronic community.

To my knowledge, there are no newsgroups dealing broadly with this issue.
Individual newsgroups may deal with the conversations happening locally,
as in the various muds newsgroups; or the topic may come up spontaneously
and then die, as it has in comp.society on occasion.  Yet the experience
of being online is central to what all of us do here:  it deserves some
special attention.

I suggest putting this new newsgroup in the comp. hierarchy because being
online is irrevocably tied up with the use of computers and information
technology.  It could also go in rec. (since we often recreate online)
or soc. (because we are a social happening) or alt. (where nearly every-
thing else ends up).  But comp. feels right to me.

I propose further that this newsgroup be moderated.  I offer to do the
moderation, at least initially.  I have been a host on USENET (sci.
virtual-worlds) for nearly a year; before that, I hosted two conferences
on The WELL and ran a legislative BBS for the California State Assembly.
My credentials are in order.

Please let the online crowd know what YOU think about this proposal.
Also, please crosspost this announcement to such other newsgroups as you
think are appropriate.  After approximately one month of discussion, I
will call for a vote on creating comp.online

Thanks for your attention and your ideas.

Bob Jacobson
Moderator, sci.virtual-worlds
 -- 
Associate Director
Human Interface Technology Laboratory
Washington Technology Center
c/o University of Washington, Seattle
206-543-5075
(Employment given for purposes of identification only; the HIT Lab
hosts only sci.virtual-worlds and has no connection to this proposal.)


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

Date: Mon, 10 Jun 91 08:34:55 EDT
From: Tom.Murray@cs.clemson.edu (Tom Murray)
To: simulation@bikini.cis.ufl.edu
Subject: Wanted: Synthetic Unix Workloads

I am constructing a simulation model of a Unix process scheduling mechanism.
I'm looking for synthetic system workloads to feed both the simulator and a 
real Unix system.  Does anyone know whether any such workloads exist in the
public domain?  I'm interested in workload models or benchmark specs for the
"typical Unix environment," whatever that is!  Although it would be nice to
find a realistic workload, that's not a requirement.  Any that are well-known
or widely-accepted by the Unix operating system modeling community should
satisfy my need.

_____________________________________________________________________________
Tom Murray						tom@cs.clemson.edu
Computer Science Department			
Clemson University



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