HDTenEightyP/NetNews huggingface dataset:
From: djoyce@black.clarku.edu (Dave Joyce)
Subject: A Diary on Information Theory
Organization: Clark University (Worcester, MA)
Date:  6 Nov 92 19:26:06 GMT

Alfred Renyi's _A Diary on Information Theory_ is reviewed by
Gregory J. Chaitlin in the new issue of _The Mathematical Intelligencer_.

The 1987 book  is Renyi's incomplete, posthumous work writeen in the form
of a fictitious student's diary.
 
-- 
David E. Joyce				Dept. Math. & Comp. Sci.
Internet:  djoyce@black.clarku.edu	Clark University
BITnet:    djoyce@clarku		Worcester, MA 01610-1477
From: gferg@hoop.csd.sgi.com (Greg Ferguson)
Newsgroups: alt.info-theory
Subject: Re: MUST READ
Date: 6 Nov 92 02:31:51 GMT
Reply-To: gferg@sgi.com
Organization: Silicon Graphics, Inc.

In article <1992Nov3.142827.10337@mnemosyne.cs.du.edu>, rbanksjr@nyx.cs.du.edu (Richard E. Banks Jr.) writes:
|> In article <1992Nov2.035733.19115@udel.edu> cooper@sol.cis.udel.edu (Dr. Brinton Cooper) writes:
|> >Whether you are in classical "information theory" or in one of the
|> >library or  information sciences, you will probably enjoy "Penguin
|> >Dreams" by Robert Lucky, formerly of AT&T Bell Labs.  It requires only
|> >college-level mathematical sophistication and will delight nearly all of
|> >you.
|> 
|> I read this book and I too recommend it for recreational reading.
|> But I remember the name being "Silicon Dreams", not Penguin Dreams."
|> >
|> >

I think that  "Penguin Dreams" was actually a collection of Bloom County
cartoons!!! hehehe
-- 
MOSH!
Ferg      "Don't hold me back...this is my own hell..."
                                                - Godflesh
Greg Ferguson - SGI CSD R&D - gferg@csd.sgi.com
From: christos@kuhub.cc.ukans.edu
Newsgroups: alt.info-theory
Subject: Why Information=-logP, why a logarithmic measure????
Date: 8 Nov 92 12:08:44 CST
Organization: University of Kansas Academic Computing Services

Hello there,

	I have a very basic question on Information Theory. The information
measure used for a symbol of a source is I = -logP where P is the probability
that the symbol occurs in the source. Intuitively, this definition makes sense
because probable events have less "value" since they occur more often. However,
what is the reason that a logarithmic measure is used? In other words, why
don't we define I = 1/P or any other function of P such that as P increases I
decreases?

	I would appreciate any relevant response.

Thanjks,
Chris.
Internet Address: cneophytou@tesla.ece.ukans.edu
Newsgroups: alt.info-theory
From: shenkin@still3.chem.columbia.edu (Peter Shenkin)
Subject: Re: Ergodic?
Organization: Dept. of Chem, Columbia U, New York
Date: Sat, 7 Nov 1992 22:38:00 GMT
Distribution: alt
X-Posted-From: still3.chem.columbia.edu
NNTP-Posting-Host: sol.ctr.columbia.edu

In article <1992Nov6.105922.4263@hellgate.utah.edu> tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:
>What is an ergodic system?
>
>  From what I know, I would define it this way (which is incorrect presumably):
>A stochastic process which over the long run keeps a steady probability of
>outputs.  The probability of certain outputs remains stationary over a long
>time, and will reach a limit as the process goes to infinity.

I believe that an ergodic path is one which will eventually touch every
point in the phase space.

	-P.
-- 
************************f*u*cn*rd*ths*u*cn*gt*a*gd*jb*************************
Peter S. Shenkin  shenkin@still3.chem.columbia.edu   Columbia Univ., Chemistry
********* DEMOCRACY:  The theory that the people know what they want, ********
********** and deserve to get it good and hard.  -- H. L. Mencken ************
From: bill@nsma.arizona.edu (Bill Skaggs)
Newsgroups: alt.info-theory
Subject: Re: Why Information=-logP, why a logarithmic measure????
Date: 8 Nov 92 20:39:31 GMT
Organization: ARL Division of Neural Systems, Memory and Aging, University of
	Arizona

christos@kuhub.cc.ukans.edu writes:

   > However, what is the reason that a logarithmic measure is used?
   > In other words, why don't we define I = 1/P or any other function
   > of P such that as P increases I decreases?

With the logarithmic measure, if A and B are independent random
variables, then the information content of the pair (A,B) is the
information content of A plus the information content of B.

So, for example, the information you get from flipping two coins is
the information you get from flipping the first coin plus the
information you get from flipping the second coin.

Other functions do not have this crucial property.

	-- Bill
Newsgroups: alt.info-theory
From: tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman)
Subject: Re: Why Information=-logP, why a logarithmic measure????
Date: 8 Nov 92 18:55:45 MST
Organization: University of Utah, CompSci Dept

>   > However, what is the reason that a logarithmic measure is used?
>   > In other words, why don't we define I = 1/P or any other function
>   > of P such that as P increases I decreases?
>
>With the logarithmic measure, if A and B are independent random
>variables, then the information content of the pair (A,B) is the
>information content of A plus the information content of B.

This is a valuable property, but it is only an "intuitive" one.  The actual
choice of logarithm is entirely arbitrary.  The first person to use the
logarithm measure  (that I know of) is Hartley (1)

Notice that any transformation of the original value to give a "measure"
is a function, and hence is not "giving anything new" or "taking anything
away".  Thus, it is perfectly reasonable to measure information by merely
looking at a probability.  Of course 0.0000001 compared to 0.000001 is
not very easy to see, and logarithm provides this along with another of
other useful properties.  Shannon chose his equation for 3 reasons... from
his paper...

1) H should be continuous in the probablity pi(hopefully!)
2) If all the probabilities from an ensemble are equal then pi = 1/n and H
   should be monotonically increasing with n
3) If there are two separate choices, then the original H should be the 
   weighted SUM of the individual H's.  (as you pointed out)

HOWEVER, one might want to examine the choice of logarithm... is it really
what we want?  Is there something better?  All of this implicitly assumes
that information is related to uncertainty... is this actually true?


1) Hartley, R.V, "Transmission of Information", Bell System Technical Journal
July 1928, p.535.



Newsgroups: alt.info-theory
From: Christopher Allen <consensus@aol.com>
Subject: Info Theory Consultant Needed
X-Useragent: Nuntius v1.1.1d12
Date: Wed, 11 Nov 1992 23:50:13 GMT
X-Xxdate: Wed, 11 Nov 92 15:42:25 GMT
X-Xxmessage-Id: <A726DA61B601032C@kip-44.apple.com>
Organization: Consensus Development

I am looking for someone in the bay area as an info-theory  consultant
for a new product my company is coming out with. We probably only need a
few hours of your time.

The information we are requesting advice on has to do with what
information to keep with usage information of keywords in a database. We
currently store the date created, the number of times modified, the date
last modified. We are considering keeping a "tickle" count (number of
times read or accessed) and date, as well as some second and/or third
order statistics.

In addition to getting advice on what additional information to store, we
are trying to weight their "cost". As some of this informaton and
statistics come with a computational cost, we must weight their utility
against them giving us useful information as to keyword relevance and
usage.

| Christopher Allen                     America Online: Consensus |
| Consensus Development               Internet: consensus@aol.com |
| 3182 Campus Drive #501                      Tel: (415) 345-1060 |
| San Mateo, CA 94403-3123                    Fax: (415) 345-1714 |
Newsgroups: alt.info-theory
From: wheelan@cs.mcgill.ca (Bill HEELAN)
Subject: Re: MUST READ
Organization: SOCS, McGill University, Montreal, Canada
Date: Fri, 6 Nov 1992 05:18:57 GMT

From article <1992Nov2.035733.19115@udel.edu>, by cooper@sol.cis.udel.edu (Dr. Brinton Cooper):
> Whether you are in classical "information theory" or in one of the
> library or  information sciences, you will probably enjoy "Penguin
> Dreams" by Robert Lucky, formerly of AT&T Bell Labs.

  I think that those who enjoy this will also like "Silicon Dreams" by
  Berke Breathed. :-)

                                                     - Bill


P.S.

  The Lucky book is a fun read.
Newsgroups: alt.info-theory
From: tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman)
Subject: Ergodic?
Date: 6 Nov 92 10:59:22 MST
Organization: University of Utah, CompSci Dept
Distribution: alt

What is an ergodic system?

  From what I know, I would define it this way (which is incorrect presumably):
A stochastic process which over the long run keeps a steady probability of
outputs.  The probability of certain outputs remains stationary over a long
time, and will reach a limit as the process goes to infinity.

  Is that correct?  Then, a sequence which began to have more and more zero's
as time went by would NOT be ergodic.  But.... how about this famous 
sequence:

123456789101112131415161718192021222324252627282930313233343536...

is that ergodic?

Why or why not?
From: mkary@math.bu.edu (Michael Kary)
Newsgroups: alt.info-theory
Subject: Article Mailing
Date: 7 Nov 92 20:39:52 GMT
Organization: Department of Mathematics, Boston University, Boston
Originator: mkary@math.bu.edu


To all those who responded to my offer to mail an offprint of my chapter on
the foundations of information theory, thank you very much for your
interest. I will mail the batch out on Tuesday (I received a few more
requests than I expected and so am running off some extra photocopies).

				Regards

				Michael Kary  mkary@math.bu.edu
From: rymon@linc.cis.upenn.edu (Ron Rymon)
Newsgroups: alt.info-theory
Subject: Re: Why Information=-logP, why a logarithmic measure????
Date: 8 Nov 92 21:57:07 GMT
Organization: University of Pennsylvania


 Even more importantly, if you want to represent a piece of information 
from an n-sized universe, you need log n bits. Another words, log n is
the *width* of a comm channel required to transmit the above info in one
time unit (this is, I think, the original definition by Shannon). Put
differently,  log n is the *magnitude* of this piece of information,
sort-of a diameter in the abstract space of information.

-Ron

---------------------------------------------------------------------------
Computer and Information Science               Tel. (215) 898-0326 (office)
University of Pennsylvania                          (215) 626-0794 (home)
Suite C, Rm 419, 3401 Walnut St, Phila, PA 19104    (215) 898-0587 (fax)
From: ingber@umiacs.umd.edu (Lester Ingber)
Newsgroups: alt.info-theory
Subject: Re: Ergodic?
Date: 8 Nov 92 20:39:39 GMT
Distribution: alt
Organization: UMIACS, University of Maryland, College Park, MD 20742

In article <1992Nov7.223800.2153@sol.ctr.columbia.edu> shenkin@still3.chem.columbia.edu (Peter Shenkin) writes:
>In article <1992Nov6.105922.4263@hellgate.utah.edu> tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:
>>What is an ergodic system?
>>
>>  From what I know, I would define it this way (which is incorrect presumably):
>>A stochastic process which over the long run keeps a steady probability of
>>outputs.  The probability of certain outputs remains stationary over a long
>>time, and will reach a limit as the process goes to infinity.
>
>I believe that an ergodic path is one which will eventually touch every
>point in the phase space.

Ergodicity also has its "practical" side, in that for most systems
only a weak ergodicity is relevant since no one really pretends to
visit all states.  A nice discussion of the problems is in Part VII of
%A S.-K. Ma
%T Statistical Mechanics
%I World Scientific
%C Philadelphia
%D 1985
 
This also is relevant in computational problems.  I have addressed
this in a review article I'm preparing,
%A L. Ingber
%T Simulated annealing: Practice versus theory
%J Statistics Comput.
%V
%S
%P (to be published)
%D 1993
For example, in a sample test problem a global minimum was obtained
among 10**20 local minima using such techniques; however, visiting
each minimum for a millisecond would take about the present age of
the universe to visit all these minima.  Similarly, in another test
problem, a global minimum was obtained among 10**50 local minima;
however, most of these are beyond a typical workstation's precision
and recognition.
 
Lester

-- 
  |  Prof. Lester Ingber               ingber@alumni.caltech.edu  |
  |  P.O. Box 857                                                 |
  |  McLean, VA 22101       703-848-1859 = [10ATT]0-700-L-INGBER  |
Newsgroups: alt.info-theory
From: glassman@aquarius.unm.edu (Jack Glassman)
Subject: Re: Ergodic?
Date: Sat, 07 Nov 92 23:27:29 GMT
Organization: Dept. of Physics & Astro, University of New Mexico, Albuquerque
Distribution: alt

I article 47 Kenneth Tolman Writes:
>What is an ergodic system?
>  From what I know, I would define it this way (which is incorrect presumably):
>A stochastic process which over the long run keeps a steady probability of
>outputs.  The probability of certain outputs remains stationary over a long
>time, and will reach a limit as the process goes to infinity.

>  Is that correct?  Then, a sequence which began to have more and more zero's
>as time went by would NOT be ergodic.  But.... how about this famous 
>sequence:

>123456789101112131415161718192021222324252627282930313233343536...

>is that ergodic?

The definition you are using is close and might actually be equivalent to the
canonical definition. The one thing you are leaving out explicitly but seem to be 
assuming implicitly is the concept of an ensemble. In terms of an ensemble 
of objects (or complete systems) the ergodic principle can be stated as follows
	An ensemble of objects is said to be ergodic if the average
	of the positions of the objects in phase space is equivalent
	to the long-time average of the positions in phase-space
	of any one object.
As an example of this, consider an atom of an ideal gas. If one were to
monitor its position and momentum over a period of time, one could 
plot the resulting set of points as a trajectory in a 6-dimensional space
(phase space). The ergodic principle states that I would obtain the same
trajectory if I plotted the 6x10^23 points (in 6-d phase space) obtained by
taking a snapshot of the phase space coordinates of all of the members of
the ensemble at a single instant.
	I believe that ergodicity implies an equilibrium and so probably excludes
the sequence you are suggesting. But this assumes that we are taking the 
members of the sequence to be the members of the ensemble and the values
to be the positions in a 10 dimensional phase space. I'm not sure this is a 
reasonable thing to assume. The lack of a time dependence that I can see in
the system also calls into question whether it is even reasonable to ask 
whether the sequence is ergodic.
	I'll think about it.
				--Jack
From: dan@seismo.pnl.gov (Dan Hagedorn)
Newsgroups: alt.autos.antique
Subject: Re: old tires, etc
Date: 12 Nov 92 19:30:35 GMT
Reply-To: dan@seismo.pnl.gov
Organization: Sun Microsystems, Inc.

In article 0q1ggr@rpi.edu, scottv@rs6414.ecs.rpi.edu (Vaughan K. Scott) writes:
>	I have a '76 TR-7 that I'm in the middle of restoring, and I've just
>gotten around to the wheels.  My problem is this:  The front tires, which
>need to be replaced, are so old that I'm having trouble getting them off
>the rims.  I have access to a tire mounting machine at the Student Auto Shop
>here at RPI, but it consistently stalls halfway around the rim.  I then tried
>to cut them off, but I just can't cut through the steel belt under the
>non-existent tread.  The rims will also have to be beaded and repainted before
>I put new tires on.  Any suggestions?
>

Scott-

Why not try soaking the tire bead adjacent to the rim with WD-40 and let sit for
a few minutes?  I have used it to loosen up most everything that has gotten
stuck.  WD-40 has really good penetrating power to get into the crack between
the tire and rim. 

After the tire is remover, you will need to wire brush the rim to a clean
surface,  If they are badly pitted from rust, your best bet would be to look 
for replacement wheels.

I am sure that someone out there has better info than my suggestions, but I
don't believe that the WD-40 will hurt, and it could only help.
From: ccdh001@utxvm.cc.utexas.edu (Clifford A. Wilkes)
Newsgroups: alt.autos.antique
Subject: Re: British cars
Date: 9 Nov 92 15:19:25 GMT
Organization: Dept. of Redundancy Dept.  University of Texas

In article <Bx9Czx.FLz@trc.amoco.com> rlindsay@trc.amoco.com (Richard O. Lindsay) writes:
>From: rlindsay@trc.amoco.com (Richard O. Lindsay)
>Subject: Re: British cars
>Date: 5 Nov 92 19:33:33 GMT


>My friend and fellow Jaguar mechanic asked me to put this note
>on the net.  The potential seller is a 70+ year old woman whose
>husband recently died.  She is now selling his collection of
>cars one-at-a-time to support herself.  So, FOR SALE is a:

>1966 E-type Coupe' (not a 2+2)  Series I (Covered headlights)
>'Black-plate' Original California Car
>No Rust what-so-ever
>British Racing Green paint & biscuit leather
>4.2L engine
>Wire wheels

>This car has been owned by original purchaser since new!
>Never has had a title change!  Absolutely original car!

>Accepting offers. Please call Mr. Paul Collins at Jagworks in
>Tulsa, Oklahoma, USA.

>(918) 834-5818 (the shop)
>(918) 836-4568 (home)

>We are in the U.S. Central Time zone.

As a former two-time E-Type owner, a current Morgan owner, and a confirmed 
Jaguarofile I find messages like this unnerving.  If the "old woman" in 
question has a roadster (preferably a '66) or an SS for sale I'd be 
interested (along with everyone else B-)).  But, this sounds a lot like 
those legends you hear about such as the fisherator.  Is this for real?

That said, if a suitable automobile becomes available I am interested.  
Unfortunately, I haven't any children to sell so I would need sufficient 
time to arrange the sale of a sibling.  B-))


                                       <@>
Newsgroups: alt.autos.antique
From: brooks@mcnc.org (Ted Brooks)
Subject: antique auto insurance
Organization: MCNC Center for Microelectronics, RTP, NC
Distribution: usa
Date: Mon, 9 Nov 1992 20:29:04 GMT

Has anyone had any experience (good or bad) with The Grundy Agency that
sells antique auto insurance through the mail? Their rates look _very_
good in their ads, but I want to know how they are to deal with if you
ever have a claim. Of the several mail order outfits (JC Taylor, Condon
& Skelly, Great American), they are the only ones who can write liability
in NC. 
 
Ted Brooks
 ______________________________________________________________________
| Disclaimer: The opinions expressed are my own, and do not reflect    |
| those of my employer. Advice is free, but you get what you pay for.  |
|                               ________                               |
|                         _____|  1955  |_______                       |
|                        /      Chevrolet      /                       |
|                       /______  BelAir  _____/                        |
|                              |________|                              |
|______________________________________________________________________|
From: achenbac@epcot.spdc.ti.com (Jeff Achenbach)
Newsgroups: alt.autos.antique
Subject: Re: British cars
Keywords: british
Date: 5 Nov 92 22:51:43 GMT
Organization: TI Semiconductor Process and Design Center

In article <899@dsbc.icl.co.uk> asj@dsbc.icl.co.uk (Adrian Jefferies) writes:
>
>Briefly, I lived in the US for a while & wanted to buy a car, a real
>American car; not a European, not Japanese - after all I can buy them in the
>UK. So, I did a bit of research, checked my bank balance & plunked my
>cash down for a '80 (I think) Plymouth Volare. Now, from where I'm
>sitting I can here you US guys laughing ... However, my rationale went
>something like this: They had been in production for years, it seemed (!)
>very solid, any auto mechanic would be familair with its innards,
>it had the famed Chrysler (?) slant-six motor that powered the
>long lived Plymouth Dusters till their wheels fell off. It had low
>mileage(?), body was excellent, interior was clean, 
>looked good on a lift, etc. It was a dog! I wont bore you with the
>details, I'm sure we all have our favourite bad-car stories.
>
>It about bankrupted me - where did I go wrong?
>

Too new. Name a memorable (good memories) car made between 1975 and 1990. 
The late seventies to at least mid eighties are dogshit. The American auto
market share was plummeting, and carmakers were struggling to survive while
trying to meet increasingly strict EPA and DOT standards. '67-'74 Darts,
Dusters, and Valiants are still plentiful and chugging right along. Slant
six performance is uninspiring, to say the least, but a little 318 can be
fun.

Jeff Achenbach
From: guy@Auspex.COM (Guy Harris)
Newsgroups: alt.autos.antique
Subject: Re: British cars
Date: 5 Nov 92 23:33:27 GMT
Organization: Auspex Systems, Santa Clara

>to request to be added to the list and thereby receive e-mailings, send your
>request stating same to:
>british-cars-request@hoosier.utah.edu
>
>However, to be safe, send the request to british-cars@hoosier.utah.edu as well.

Unless "british-cars" is an unusual mailing list, it's a tad antisocial
to send requests to be added to, removed from, or have one's entry
changed on the list to the list itself.  Most of the recipients of the
message are in no position to respond to it, and might be annoyed by
Another Useless Mail Message showing up in their mailbox.
Newsgroups: alt.autos.antique,rec.autos.tech
From: whs70@dancer.uucp (22501-sohl)
Subject: TR-7 V6, was...Re: British cars
Organization: Bellcore, Livingston, NJ
Date: Fri, 6 Nov 92 14:14:13 GMT

In article <92310.152836KXN2@psuvm.psu.edu> KXN2@psuvm.psu.edu (Karl Nordstrom) writes:
>eric@eeco.cba.ufl.edu (Eric E.C. Olson) says:
>>
>>I saw an ad at the back of this month's Hot Rod for an outfit that sells V-6
>>conversion kits for the Triumph TR-7.  Has anyone done this, or even seen it?
>>What's the availability of HiPo intakes, cams, etc. etc. etc. for V-6s?

I drove one of the "John's Cars" converted TR-7 V6s several years ago
when one was brought to the Vintage Triumph Register's national
convention that year.  It was certainly a quick and admirable performer.
I belive the V6 that was used was a Ford.  From my perspective as
a Triumph enthusiast, I'd prefer to see the TR-7s, for those that are
interested in engine swapping, converted to the Rover V8.  There are
kits available for that purpose and the Rover V8 is reasonably available.

As to the mods that might be available for any domestic V6...I'd think that
there'd be plenty in the "Hot Rod" catalogs as the V6 has been a 
mainstay of engine production for many years now here in the USA.

Standard Disclaimer- Any opinions, etc. are mine and NOT my employer's.
-----------------------------------------------------------------------
Note - If email replying to me with an automatic addressing process
bounces, manually address the resend using one of the addresses below.
-----------------------------------------------------------------------
Bill Sohl (K2UNK) BELLCORE (Bell Communications Research, Inc.)
Morristown, NJ             email via UUCP      bcr!dancer!whs70
201-829-2879 Weekdays      email via Internet  whs70@dancer.cc.bellcore.com

Newsgroups: alt.autos.antique