HDTenEightyP/NetNews huggingface dataset:
From: dbarberi@mailbox.syr.edu (London W11)
Subject: Re: TECH: Virtual-worlds on the net?
Originator: hlab@milton.u.washington.edu
Organization: Syracuse University, Syracuse, NY
Date: Wed, 9 Sep 1992 19:11:27 GMT



In article <1992Sep9.000709.20966@u.washington.edu>
tcasady@nyx.cs.du.edu (tim casady) writes:

>Anyone who knows of articles/books/sources/etc. that deal with the
>virtual worlds on the net (the virtual environments found in mud's or
>boards rather than full-blown 3-d virtual reality systems) or who has
>strong interest in such worlds:
 
   Off the top of my head..

     _Electropolis_ By Elizabeth Reid.  It's a study of the 'society'
     of IRC.  Avaiable on a few anonymous FTP sites, including
     sugrfx.acs.syr.edu /pub/vr/papers/electropolis
     It also has a large bibliography that you might find usefull.
 
     _Tools For Thought_ By Howard Rheingold.  The last half of the book
     goes into network culture.
 
>I doing graduate research on the communication that occurs in the
>virtual-worlds on the net.  Specifically, this deals with human to
>human communication and how the net affects it.  This covers a lot of
 
   I've been looking around for Grad schools that support this type of
research.  Does anyone know what schools would be good to look into?
 

------=============-----------------------------------------------------------.
      David Barberi                                                           |
dbarberi@sugrfx.acs.syr.edu      Computer-Mediated Communications Researcher  |
 dbarberi@mailbox.syr.edu                                                     |
  dbarberi@ccvm.wcupa.edu               Resume available upon request         |
______________________________________________________________________________|

[MODERATOR'S NOTE:  Try Ohio University, Houston University (futurism
program), Simon Fraser University in North America.  Others? -- Bob Jacobson]
Newsgroups: sci.virtual-worlds
From: glens@natinst.com (Glen Sescila)
Subject: TECH: Software for SEGA glasses
Originator: hlab@milton.u.washington.edu
Organization: National Instruments, Austin, TX
Date: Tue, 8 Sep 1992 20:13:55 GMT



Is there any software in the public domain (ftp' able) that readily
supports the glasses?  I downloaded SEGA.code but it requires you to
draw your own picture(s) (it supplys writepixel()) and it doesn't even
control the glasses for you!  How misleading.  I just want to run
something that will exhibit the glasses.

Thanks.
-----------------------------------------------------------------------------
"Now You're Playing With Power Without The Price!"  Glen Sescila   |||
                                                                  / | \
My opinions do not necessarily reflect those of my employer and probably are
exact opposites.        InterNet: glens@natinst.com     GEnie: G.SESCILA
-----------------------------------------------------------------------------
Newsgroups: sci.virtual-worlds
From: pvanheus@frodo.cs.uct.ac.za (P A van Heusden)
Subject: WHO: Looking for Jaron Lanier
Originator: hlab@milton.u.washington.edu
Organization: Computer Science Department, University of Cape Town
Date: Tue, 15 Sep 1992 10:56:25 GMT



I am looking for an address where I can contact Jaron Lanier, related
to a project I am working on (a glove driven instrument).

Email address would be great, but failing that, snail mail address is
fine.  Phone is out of the question, unfortunately. International
calls from RSA just cost too much.

Peter

*******************************************************************************
Peter van Heusden              "Thou shalt not kill
CS2 lab, UCT, Cape Town               Kill kill kill!"
pvanheus@frodo.cs.uct.ac.za                    Ministry   
Newsgroups: sci.virtual-worlds
From: jew5001@venus.tamu.edu (WILLIAMSON, JOHN EDWARD)
Subject: VGA to NTSC boards, Fightertown, USA
Originator: hlab@milton.u.washington.edu
Organization: Texas A&M University, Academic Computing Services
Date: Mon, 7 Sep 1992 15:23:31 GMT



PC Magazine (September 29, 1992, Vol 11(16)) has a fairly
comprehensive review of VGA to NTSC boards for those of you
contemplating this design in you next homebrew VR project.

Fightertown, USA is the latest commercial venture in the loosely
defined "virtual reality" market.  Designed and built by three
aerospace engineers with experience in high-end military simulations,
Fightertown allows several players to be linked together over
Fighternet (what else) and fly missions either as opponents or allies.
What sets this simulation apart is that each player is given a full
flight suit and is placed inside what look (to me anyway) like
full-sized, authentic cockpits.  The images are projected on a 10' X
12' screen at 1,000 line resolution in front of each cockpit.  To date
there are an F-111, F-104 and an F-4.  The F-111 and the F-4 are
two-seaters.  Fightertown, USA is located at 8 Hammond Road, Irvine,
CA 92718.  (714) 855-8802.  They are closed mondays.  Sorry, the
article I read had no information on pricing.

John W.
From: jlenarci@monu6.cc.monash.edu.au (John Lenarcic)
Newsgroups: sci.virtual-worlds
Subject: TECH: Looking for economical PC-based VR hardware/software
Date: 12 Sep 92 04:21:31 GMT
Organization: Monash University, Melb., Australia.
Originator: hlab@milton.u.washington.edu



I'm looking for a "cheap" but effective configuration of
hardware/software to enable me to develop rudimentary VR applications
on my trusty 486 PC - at least at an experimental level. ( Ideally,
I'm seeking something better than the the offerings in "cheap-vr"
within milton.u.washington.edu) Any tips in the right direction would
be most appreciated.  Many thanks.

                cheers,
                
                John Lenarcic

                Postal address:
                Department of Software Development,
                Monash University,
                P.O. Box 197,
                Caulfield East, Victoria 3145
                AUSTRALIA

                Fax number: 61-3-5732745

                E-mail address:
                jlenarci@monu6.cc.monash.edu.au
From: cyberoid@u.washington.edu (Bob Jacobson)
Newsgroups: sci.virtual-worlds
Subject: CONF: Cheap tickets to Meckler from Seattle
Date: 12 Sep 92 00:21:31 GMT
Article-I.D.: u.1992Sep12.004249.11275
Organization: WORLDESIGN, Seattle
Originator: hlab@milton.u.washington.edu



WORLDESIGN's landlord and VR aficianado, Dick Olsen, has secured
exceptionally cheap air tickets from Seattle to San Jose and back, 
for the Meckler VR conference: about $119 rountrip.  Leave Seattle 
on Sept 22, return on Sept 26.  For more information, call Olsen 
at 206-782-6020 (Olsen Furniture, in beautiful downtown Ballard).
Newsgroups: sci.virtual-worlds
From: thiel@hardy.u.washington.edu (me me me me...)
Subject: Re: TECH: FLY! VR Software
Originator: hlab@milton.u.washington.edu
Organization: University of Washington, Seattle
Date: Mon, 14 Sep 1992 20:42:59 GMT



Where is this FLY! software available? looks interesting...

thiel@u.washington.edu
From: billc@Apple.COM (Bill Cockayne)
Newsgroups: sci.virtual-worlds
Subject: PHIL: Virtual Worlds discussion
Date: 9 Sep 92 07:55:24 GMT
Article-I.D.: u.1992Sep12.000222.9695
Organization: Apple Computer Inc., Cupertino, CA
Originator: hlab@milton.u.washington.edu



Bob made some very interesting comments as to why the is a sci.
newsgroup as opposed to a .comp group. The idea that all virtual
worlds must stem from computers is a very narrow view, but is
predominant in this newsgroup.

As I have just finished reading "Virtual Reality" by Howard Reignhold
(forgive my lateness in reading this book...too much Alvin Toffler
lately). He hops all around the VR map discussin projects, people, and
history associated with different areas. The most interesting part
concerned a Sensorama system that was built a number of years ago (all
facts elude me, and the book is at home).  The system was a very early
VR system based on movies and used sound, pictures, wind, smell, and
motion to immerse the user in another reality. It is obvious that this
is a VR application.

Also, many people have related to me the idea that drugs allow the
user to enter another world. This has some interesting reprecussions
since many cutting edge companies are now starting drug-testing. It
would be a shame if the people that have the best ideas for other
worlds were to be removed from the industry since they used drugs,
which probably started them down the path in the first place. (PS -
This is not an add for drug use. Personally don't use them and am
against their use.)

Finally, there is the simple concept of a virtual world being invoked
merely by the suspension of disbelief by the user. Having attended
many a play and movie I feel that there is a virtual world quality
exhibited at these events and that a large amount of study is being
neglected by not looking at how the public is affected by these
already dominant worlds. (I won't even start on the imaginary worlds
that TV creates) :)

Virtual World discussions include people from all areas of industry
and academia not just computer hackers. Though much of the discussion
seems at times to be dominated by the hackers the other fields often
pop up when discussions interfaces, paradigms, and already existing
models of human behaviour.

bill cockayne
Apple Computer, Inc.
billc@apple.com
DISCLAIMER: I speak only for myself.
Newsgroups: sci.math
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Warm and Fuzzy?  Koalas vs. Math
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Sun, 13 Sep 92 21:05:51 GMT

andrew@rentec.com (Andrew Mullhaupt) writes:
>In article <22218@galaxy.ucr.edu> baez@ucrmath.ucr.edu (john baez) writes:
>>In article <1223@kepler1.rentec.com> andrew@rentec.com (Andrew Mullhaupt) writes:
>>>In other words, I defy anyone to make sensible the claim that mathematics is
>>>_not_ a soft, warm fuzzy, human frailty. 

>>Mathematics is clearly a human activity and as such subject to all the foibles
>>of any other human activity, but it is NOT warm and fuzzy.  It is cool and
>>smooth.  If you want something warm and fuzzy, raise koala bears.

>Ever checked the claws on those bears?

That's the usual drawback of warm and fuzzy things - they come with
claws!  :-) 

>But mathematics is not cool and smooth unless you want it to be.

I do.  Rather, I love it for that quality, and prefer to get my warmth
and fuzziness elsewhere.  

>There are only a very few activities that no civilization seems to manage
>without for very long. Mathematics is one of them. It lies very close to
>some of the deepest human urges - certainty, truth, beauty, security, you
>get them all in math. Presumably, you regard these as "cool and smooth"
>and a bit like impersonal Hellenistic abstractions.

Yup.

>But in this century,
>we find that there are different possibilities for the "true truth" of math-
>and we have to _choose_ which one we _want_. Anything as central to human
>culture as mathematics is is warm and fuzzy it you look at it close up.

Well, to me "warm and fuzzy" doesn't just mean subject to
human choice and human foibles.  I think of teddy bears, sweaters,
roasting chestnuts by the fireside, and other cozy activities. 
Mathematics to me has an attraction of a very different flavor, which
I can only try to convey as that of an infinitely dazzling, infinitely
complex labyrinth of diamantine crystal - of course there is complete
freedom of choice about which way to wander in this labyrinth, and
it's easy to get seduced into endless exploration of even the most
minor passageways, which open out into further passageways....

All this is utterly personal and not worth arguing about any more than
the best flavor of ice cream.  
  
>You've made the claim - try making it stick. 

I made a wisecrack and now I'm beginning to regret it.  


.


Newsgroups: sci.math
From: dak@tabaqui.informatik.rwth-aachen.de (David Kastrup)
Subject: Re: Retarded log question
Organization: Rechnerbetrieb Informatik  /  RWTH Aachen
Date: 12 Sep 92 18:49:19 GMT

tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:


>If you are given a number, such as 2^X, how can you determine what
>the same number would be with a different base, such as 10?

>For example, 2^100,000,000 = 10^ ??
100,000,000  \log_{10} 2
>Thanks a lot
Not to mention it.
Newsgroups: sci.math
From: ezli@ntuix.ntu.ac.sg (Li Ziqing)
Subject: Nonlinear Diff. Equ.
Organization: Nanyang Technological University - Singapore
X-Newsreader: Tin 1.1 PL4
Date: Wed, 9 Sep 1992 14:38:00 GMT
From: sklar@picasso.ocis.temple.edu (Dave Sklar)
Newsgroups: sci.math
Subject: Prime Factor Numbers
Date: 8 Sep 92 04:03:07 GMT
Organization: Temple University
X-Newsreader: Tin 1.1 PL5


	Here's something I was thinking about.  Take a number, n, and write
down its prime factors [Excluding n and 1] from left to right, forming a new number.  Repeat.
	When you get to a prime number, you end. Let's call the function
d(n).  So, d(1001)=71113, d(5)=d(2)=d(11)=[Define something here, say]0.
	Does every number eventually go to a prime, and then 0?
	What happens if you include the 1 and n?  What happens if you write
prime factors that occur more than once once for each time they occur
instead of once for any number of times they appear? [d(20)=225 instead of
d(20)=25]

	If anybody has any references, as well, I'd love to see them.

Post or email.

Dave
Newsgroups: sci.math
From: vhansen@ipfs.bau-verm.uni-karlsruhe.de (Wolfgang von Hansen)
Subject: how to find 1/x
Organization: IPF, University of Karlsruhe
Date: Wed, 9 Sep 1992 12:22:05 GMT

Hi everybody,
I'd like to know if there is an easier (and faster) way to solve y = 1/x
without performing a single division? If you have got any ideas, please mail
them since I don't have the time to read this board regulary.

Thanks in advance,  Wolfgang
From: tage@ii.uib.no (Tage Steffensen)
Newsgroups: sci.math
Subject: Graph Problem
Keywords: Combinatorial problem, bipartite graphs.
Date: 7 Sep 92 08:45:11 GMT
Organization: Dept. of Informatics, University of Bergen

Let G = (V,U,E) be a bipartite graph such that V and U are two disjunct sets of
vertices and E is a set of edges connecting vertices from V to U. 

Further make the following assumptions. 

   - each V has exactly l edges. ( l < | V | )
   - |V| <= |U|. 

   - foreach subsett v of V there are at least |v| distinct vertices in U that
    are connected  to the vertices in v. 

	example. V = 1, 2, 3. 
		 U = ( a, b, c, d )
		 l = 2
		 E = { (1a) (1b) (2c) ( 2d) ( 3b ) ( 3d ) }
	 	 v = ( 1, 3 ). We then know that 1 and 3 must be connected to at
		 least 2 different vertices  in U. 
		 
                 The vertices in U that is connected to a vertice in v is (a, b, d )

A perfect matching is a matching of pairs of vertices one from V and one from U,
such that all  vertices in V is matched to a vertice in U. 

The vertices can onlu be matched if there is an edge from the vertice in V to the
one in U. 

A perfect matching in the example is ( 1=a, 2=c, 3=b )
Other solutions will be ( 1=a, 2=c, 3=d ) ( 1=a, 2=d, 3=b ) and ( 1=b, 2=c, 3=d)

My problem is : can anything be said of the number of perfect matching in this
graph given the definitions over. 

I've been trying to find a formula that will tell me how many solutions there are 
to this problem. The formula should take in account the number of vertices in V, the
number of vertices in U and the costant l that says how many edges there are from each
V. 

If it is not possible to find such a solution is ut possible to say anything of the range
of the number. example there are at least k1 matching's and no more than k1. 

Also note that we are sure that there will exist at least one matching under the
given conditions. 


-- 
I der treder her inn, lat alt haap fare. 
-- Oppslag over hovedfagslesesal i informatikk.  
Newsgroups: sci.math
From: ttw@beta.lanl.gov (Tony Warnock)
Subject: Re: Some BIG and SMALL sets of integers.
Organization: Los Alamos National Laboratory
 
 
  How does the "smallness" of sets lacking 3-digit distribution
  compare with Besicovich's proof that almost all integers
  are n-epsilon normal. That is, digit strings of length
  n occur with correct frequence to within epsilon if large enough
  numbers are considered.
 
  This result seems to be almost (but not quite) contradictory
  to that of the sums of reciprocals.
 
  Or maybe I've missed the whole issue.
 
                               Tony Warnock
 
 
                              It's a bug - it's not a feature;
                              Its an ugly little creature.
                              Every time that I improve it,
                              Code-rewriting to remove it;
                              It just metamorphosizes
                              In another of its guises.
                              Yet again disgruntled users
                              Deem me one of their abusers.
                              Loathe to sit around and fidget
                              I create another digit;
                              Tack it on the public version;
                              Then for marketing coercion:
                                I announce another UPGRADE!
Date: Sat, 12 Sep 1992 23:20:24 GMT
From: ara@zurich.ai.mit.edu (Allan Adler)
Newsgroups: sci.math
Subject: Re: Freedman-Donaldson Theorem
Date: 11 Sep 92 07:37:52 GMT
Organization: M.I.T. Artificial Intelligence Lab.


Several people have suggested various books aimed at making it easier to
prepare one to read the Freedman-Donaldson proof (which I haven't read).
I usually find it somewhat discouraging to be given a list of several
books to read, each of which will in turn present its own difficulties,
and to resolve the variations in notation, conventions and points of
view of various authors, when all I really want is to read a particular
paper or accomplish a particular task. It is sort of like saying, "You can't
just DO that. You first have to become someone who DOES that."

Maybe the Freedman-Donaldson paper is too hard just to read directly.
But why not determine that based on an attempt to read it first hand
and to decide for oneself exactly what one needs to know to read it
and how to learn what one needs to know?

Having said which, perhaps someone can post the reference to the article
in which the result was first published?

Allan Adler
ara@altdorf.ai.mit.edu
From: N020BA@tamvm1.tamu.edu
Newsgroups: sci.math
Subject: What is a spline?
Date: 15 Sep 1992 18:24:35 GMT
Organization: Texas A&M University


     What is a spline? Reply either by E-mail or to the net. Thank you very
much!
 
========================================================================
The truth may hurt, but lies hurt more.  | My opinions are mine and mine
The difference between left-wing incomp- | alone. I speak for myself and
etance and right-wing incompetance is    | no-one else.
the difference between cat #$!& and dog  |______________________________
#$!&. Reply to N020BA@tamvm1.tamu.edu.        Bill and Opus in '92!!
Newsgroups: sci.math
From: levine@symcom.math.uiuc.edu (Lenore Levine)
Subject: More About the Collatz Function 
Organization: University of Illinois at Urbana
Date: Sat, 12 Sep 1992 17:37:39 GMT

I was messing around with the Collatz function this weekend.

My idea is that you can prove interesting things about it if
you can prove something else about another function.  

I call it the smallest nontrivial backward iterate (SNBI) function.

You notice, in the Collatz function, every odd number that is not
divisible by three has nontrivial odd preimages. (The preimages of
an odd number divisible by three are just an infinite path).

What I want to do is get from an odd number not divisible by three,
via the smallest path possible to another odd number not divisible
by three.

That is, if n is an odd number not divisible by three, the following
algorithm obtains SNBI(n):

(Written in Pascal.)

repeat 
 n := n*2;
until (n mod 3 = 1) and (n mod 9 <> 1);
snbi := (n - 1) div 3; 

From SNBI(n) I get another function, r(n). r(n) is a real number 
between 0 and 1, determined as follows: 

The first digit after the decimal is SNBI(n) mod 9. The second digit
after the decimal is the second iterate of SNBI of n mod 9 (that is,
SNBI(SNBI(n)) mod 9). Continuing, the kth digit after the decimal is
the kth iterate of SNBI of n mod 9 (SNBI^k(n) mod 9). Note all
digits of r(n) will be 1, 2, 4, 5, 7 or 8.

My idea is that if you can show r(n) is not rational for all
n for which SNBI is defined, you may have more insight into the 
Collatz function. 

How to proceed: Maybe showing that *any* sequence of the digits used
will pop up if SNBI is repeated on n enough times...
Newsgroups: sci.math
From: rwc124@rsphy1.anu.edu.au (Roderick Vance)
Subject: Hermetian Matrix Lie Algebra
Reply-To: rwc124@rsphy1.anu.edu.au (Roderick Vance)
Organization: Optical Sciences Centre, Australian National University
Date: Mon, 14 Sep 92 13:22:39 GMT

About a fortnight ago i posted the following question on the net:

I begin with a given set H of hermetian matices, whence i form the set
of unitary matrices:

U1 = {exp(i h) : h belongs to H}

I wanted to find the group generated by members of U1. A kind newsgroup
reader offered me the following advice:

"...it is (comparitively) easy to compute the group generated by all
exponentials of a fixed set of Hermitian matrices.  It is the
exponential of the Lie algebra generated by those matrices."

Now, having just begun to teach myself Lie algebra&group theory, i'd
be most grateful if someone could comment on whether my following
interpretation of the above advice is right...

I take for example, just two hermetian matrices h1 and h2. I find
the Lie bracket

[h1,h2] =  h1 h2 - h2 h1 (usual matrix product)

to get a third matrix. I add this to my set, form all the Lie brackets
possible and add them to the set and repeat until i have the smallest
set L = {l1,l2,l3,l4,....} that both contains {h1,h2} and has the property
that [x,y] belongs to L whenever both x and y do. Then the group 
generated by {exp(i h1),exp(i h2)} will be:

{exp(i (a1 l1 + a2 l2 + ...)): l1,l2,... belong to L, a1, a2 ... are scalars}

I'd also LOVE a simple reference/explanation of why this works. Presumably,
such a proof would use the fact that commutators of L's members are
also members of L to show that:

exp(i l0) exp(i (a1 l1 + a2 l2 +...)) =
exp(i (a1' l1 + a2' l2 + ...)) for any l0 in L

and the required result would then follow by induction. I can't quite seem
to solve it!

Sorry to bother the net with non-research forefront questions but i'm sure
someone out there knows Lie theory inside out.

Many Thanks In Advance

Roderick Vance
Optical Sciences Centre
Australian National University.

By the way, the physicists amongst you may be interested to learn that
my problem 
arises in a study of n coupled, single-moded optical waveguides. If
field amplitudes 
[x1,x2,x3,...] drive the inputs then the ouput after distance z will be
U(z) [x1,x2,x3,...] 
, where U(z) is an nxn square matrix fulfilling:

(d/dz) U(z) = i K(z) U(z),

K is an nxn square matrix of coupling co-efficicents between the guides.
If the system
is lossless, K is hermetian and U is therefore unitary. I am interesed
in what input to
output transfer functions U(z) i can realise with a restricted set of
K.
From: vm0h+@andrew.cmu.edu (Vincent J. Matsko)
Newsgroups: sci.math
Subject: Re: help me, please
Date: 10 Sep 92 05:52:31 GMT
Article-I.D.: andrew.IefpATy00VpOMAoFQ6
Organization: Doctoral student, Mathematics, Carnegie Mellon, Pittsburgh, PA

It seems that the integral you seek is just another way of getting the
value of the volume of the n-dimensional simplex with one vertex at the
origin, and n vertices which have (n-1) zeroes and one 1.  In
2-dimensions, this is just a 45-45-90 triangle with vertices (0,0),
(0,1), and (1,0).  Area = 1/2.

An induction argument to compute this volume for any n is straightforward.

Vince