HDTenEightyP/NetNews huggingface dataset:
From: hinz@picard.med.ge.com (David Hinz Mfg 4-6987)
Subject: Re: Skittles commercial
Organization: GE Medical Systems, Magnetic Resonance
X-Newsreader: Tin 1.1 PL5
Date: Tue, 18 Aug 92 11:50:56 GMT

Chris Long (clong@remus.rutgers.edu) wrote:
: In article <1992Aug10.163022.12987@dg-rtp.dg.com>,
: banksd@hydra.rtp.dg.com writes:
: 
: > I saw a commercial for Skittles candies, where they are
: > trying to figure out the number of "different combinations"
: > of Skittles. Their final answer is remarkably small -- only
: > six digits -- for a combinatorial property of a bag full of
: > candy. And as I recall, it wasn't very divisor-rich either.
: 
: A friend of mine claims that the number is 371,292.  Now, how did
: they arrive at it?

Just my cynical guess, but probably some marketing pinhead came up with a
'good sounding number'.


--

Dave Hinz  -  Opinions expressed are mine, not my employer's.  Obviously.
hinz@picard.med.ge.com


Newsgroups: sci.math
From: torkel@sics.se (Torkel Franzen)
Subject: Re: Expansion of set theory
Organization: Swedish Institute of Computer Science, Kista
	<1992Aug12.164408.10547@thunder.mcrcim.mcgill.edu>
	<1992Aug12.182912.4659@sics.se>
	<1992Aug13.174408.10574@thunder.mcrcim.mcgill.edu>
Date: Thu, 13 Aug 1992 19:06:45 GMT

In article <1992Aug13.174408.10574@thunder.mcrcim.mcgill.edu> boshuck@triples.
math.mcgill.ca (William Boshuck) writes:
       
       >On the other
       >hand, I don't quite know what theorems you may be talking 
       >about. A big theorem in this area, that there is no uniform 
       >algorithm to decide whether a given Diophantine equation has
       >solutions (due to Matiesevitz (spelling?) I think) doesn't 
       >use any aspects of the theory of large cardinals (an easy
       >presentation of this theorem can be found in Bell and 
       >Machover's book on mathematical logic).

   I had in mind the following application of the theorem of Matiyasevic
(which built on work by Davies, Putnam, and Robinson). The theorem states
that every recursively enumerable set is Diophantine, i.e. is equal to
the set of k such that the equation P(k,x1,..xn)=0 has a solution, for some
integer polynomial P. This is very remarkable. The theorem is, as you note,
elementarily provable. This means that an ordinary consistency statement -
say "ZF is consistent" - is elementarily equivalent to the statement that
a certain Diophantine equation has no solution. Since the consistency
statement is provable e.g. in ZF+"there is an inaccessible cardinal", the
assumption that there is an inaccessible cardinal has consequences regarding
the unsolvability of Diophantine equations that are not provable in ZF
itself.

  For a given Diophantine equation - e.g. Fermat's - this of course tells
us nothing. But it is a striking fact concerning the relation between
"concrete" and "metaphysical" mathematics that should be more widely known
than it is.
From: stucki@retina.cis.ohio-state.edu (David J Stucki)
Newsgroups: sci.math
Subject: Re: Sequence
Date: 13 Aug 92 16:57:46 GMT
Organization: Ohio State University Computer and Information Science
Originator: stucki@retina.cis.ohio-state.edu

In article <s9054960.713717884@rkw-risc> s9054960@rkw-risc.cs.up.ac.za () writes:


   What is the next number in the sequence, and how did you get it?

   2 3 3 5 10 13 ...

2 3 3 5 10 13 4

it's my social security number :^)

dave...

David J Stucki               /\     ____          /\ Department of Computer and
537 Harley Dr. #6           /__\   \ /\ /  /\    /__\       Information Science
Columbus, OH  43202        /\  /\   \--/  /__\  /_\/_\    2036 Neil Avenue Mall
stucki@cis.ohio-state.edu /__\/__\   \/        /\    /\      Columbus, OH 43210
                                              /__\  /__\    __
There is no place in science for ideas,      /_\/_\/_\/_\   \/  /\     /\
there is no place in epistemology for knowledge,                --    /__\
and there is no place in semantics for meanings.  -- W.V. Quine      /_\/_\
From: columbus@strident.think.com (Michael Weiss)
Newsgroups: sci.math
Subject: space-eating curves: correction
Date: 17 Aug 92 09:33:08
Organization: Thinking Machines Corporation, Cambridge MA, USA
Distribution: sci
NNTP-Posting-Host: strident.think.com
In-reply-to: columbus@strident.think.com's message of 14 Aug 92 16:51:16


I wrote:

   Topologically, H [the Hilbert cube, I^{aleph_null}] is the product of
   countably many copies of I with the product topology.  Equivalently, for
   x in R^{aleph_null}, define ||x|| to be sqrt(sum (x_i)^2) (setting ||x||
   = infinity of course if the series diverges; otherwise this is the usual
   l^2 norm); then sets of the form N_e(x) = {y : ||y-x|| < e} form a
   neighborhood base (with e>0, of course.)

What was I thinking?  This "norm" gives a finer topology than the product
topology.  (A neighborhood base for H with the product topology consists of
products of the form {Product A_n | n=1 to infinity}, where all A_n are
subintervals of I open in I, and all but finitely many A_n equal I.  Here
I=[0,1].  No such product can be a subset of the set N_1(0) defined above,
for example.)

This fallacious remark was really parenthetical to the main point of my
post, but for the record, what I had in mind was the fact that H is
metrizable.  A correct formula for a suitable metric is:

	d(x,y) = sqrt {sum ((x_n - y_n)/n)^2 | n=1 to infinity}

where x = (x_1,x_2,...) and y = (y_1,y_2,...)
From: wilson@web.ctron.com (David Wilson)
Newsgroups: sci.math
Subject: What is the EATCS?
Date: 17 Aug 92 18:55:17 GMT
Reply-To: wilson@web.ctron.com (David Wilson)
Organization: Cabletron Systems INc.
Originator: wilson@web


    Here I have a paper in the EATCS and I still do not know what it
    stands for.


-- 
David W. Wilson (wilson@ctron.com)

Disclaimer: "Truth is just truth...You can't have opinions about truth."
- Peter Schikele, introduction to P.D.Q. Bach's oratorio "The Seasonings."
From: edgar@function.mps.ohio-state.edu (Gerald Edgar)
Newsgroups: sci.math
Subject: Re: Skittles commercial
Date: 18 Aug 1992 12:31:37 -0400
Organization: The Ohio State University, Dept. of Math.
NNTP-Posting-Host: function.mps.ohio-state.edu

>: A friend of mine claims that the number is 371,292.  Now, how did
>: they arrive at it?

It says on the screen:
    371,292!
Maybe that's a factorial?
-- 
  Gerald A. Edgar                Internet:  edgar@mps.ohio-state.edu
  Department of Mathematics      Bitnet:    EDGAR@OHSTPY
  The Ohio State University      telephone: 614-292-0395 (Office)
  Columbus, OH 43210             -292-4975 (Math. Dept.) -292-1479 (Dept. Fax)
Xref: sparky sci.math:10413 sci.psychology:3520
From: zorrilla@cattell.psych.upenn.edu (Eric Zorrilla)
Newsgroups: sci.math,sci.psychology
Subject: Re: mathematician's marrying ages.
Date: 19 Aug 92 21:07:35 GMT
Followup-To: sci.math
Organization: University of Pennsylvania

In article <1992Aug19.185215.303@cc.tut.fi> jk87377@cc.tut.fi (Juhana Kouhia) writes (clarifying previous statement about loneliness -> illness/mortality
link):

>I have read from the newspapers about animals in zoos, how they
>are lonely (alone) and actually die for their loneliness (also after
>their partner has died).
>I have also read about how some elder people die soon after
>the dead of their wife/husband.

First, I must say that I am not challenging the connection you are asserting
on the face of it.  This is some of the stuff that I research, so it's not
like I don't think there's a strong possibility (factualhood?) of it existing.

That said, the relationship between bereavement and spousal illness or even 
death does seem to be a pretty well-established one, thought the mechanisms
are unclear.  We don't know what portion of the illness is attributable to
behaviors (drinking more, eating less or just generally taking less care of
one self after your spouse dies) and what portion is attributable to more di-
rect neuroendocrinological modulation of immune function.  To say that animals
are dying from "loneliness" may be anthropomorphosizing (sp?), though.

>So, the researchs I have read about tells that
>people married lives longer and are more healty than
>people not married.

OK, this is a wholly separate issue and is the one that I was taking issue
with in your previous post.  You had said that people who were lonely (alone?)
were more likely to develop mental problems (or health-related problems
more generally).  I know of no prospective study which
illustrates this point.  If you don't start with as similar as possible people
and follow them prospectively, there's no way you can interpret the cause
to be "marital status" or "loneliness."  It could be, for example, that
some people don't get married for a 3rd reason (very anxious about initiating
social relationships) and that that social anxiety is contributing to their
increased mortality.


[--------------------------------------+--------------------------------------]
| Eric Zorrilla - Dept. of Psychology  | zorrilla@cattell.psych.upenn.edu     |
| University of Pennsylvania           | 3815 Walnut, Philadelphia, PA 19104  |
[--------------------------------------+--------------------------------------]
From: hamid@imada.ou.dk (Hamid Sarabi)
Newsgroups: sci.math
Subject: min distace between a point and a polygon
Keywords: min distance
Date: 14 Aug 92 14:23:00 GMT
Organization: Dept. of Math. & Computer Science, Odense University, Denmark

I have a point and a convex polygon(set of ordered points). 
How can I find the distance, if the projection of the point is outside of polygon.

Thanks,
Hamid S.
email: hamid@imada.ou.dk
From: crb11@cus.cam.ac.uk (Colin Bell)
Newsgroups: sci.math
Subject: Graph Theory problem
Date: 15 Aug 92 02:14:35 GMT
Organization: U of Cambridge, England

01234567890123456789012345678901234567890123456789012345678901234567890123456789
A friend (Adam Chalcraft) posed the following problem:

1. Given a connected planar graph in which all regions (not including the outside region) are triangles, is it possible to represent it by (disjoint) rectangles such that two rectangles meet at an edge iff the points that they represent meet.

For example,
      C                                      --- --- -------                  
       o                                    !   !   !   C   !
      / \                                   !   !    -------
A   B/   \ D   E                            ! A ! B !   D   !
o---o-----o---o        is represented by    !   !    -------
     \   /   /                              !   !   ! F ! E !
      \ !   /                                --- --- --- ---
       \!  /
        o--
        F

2. If 1 is possible for a given graph, is it possible to do it so that the rectangles put together form a rectangle as in the above example.

Note that there are trivial counterexamples to both 1 and 2: for example in 1, if you have an internal point of degree <=3 then it fails, since its rectangle must have at least  four distinct neighbouring rectangles.

For 2, consider the graph:

  o
  !
o-o-o
  !
  o   

It clearly has a representation (one large square with a small square attached to each side, for example) but no rectangular representation.

Both problems have rather nice solutions and quite a nice proof, which I will email to people on request.

Now a question for the experts: is this problem or related ones known in the literature? If so, please send me a reference or other information.
-- 
Colin Bell, CRB11@CUS.CAM.UK.AC
Department of Pure Mathematics, University of Cambridge.
Newsgroups: sci.math
From: sasmb@carroll.unx.sas.com (Miguel Bamberger)
Subject: Re: Young Gauss and the arith. series (was: Bell's _Men of Mathematics_)
Originator: sasmb@carroll.unx.sas.com
Date: Wed, 12 Aug 1992 13:20:21 GMT
Organization: SAS Institute Inc.


|> >>The story is "usually" told in one of two ways.  In Bell's book[1] it says:
|> 
|> >>   The problem was *of the following sort*, 81927 + 81495 + 81693
|> >>   + ... + 100899, ....

W.K. Buehler: "Gauss, A Biographical Study" Springer Verlag 1981. makes
almost no mention of the story.  The author says (p. 7): "He [Gauss] was
unusually lucky ...  for his teacher, Buettner, seems to have been
competent and concerned. He took a personal interest in the boy, trying
to help and encourage him".  Later on there's an endnote in reference to
Gauss' precociousness: "The statements in this and the preceding
sentence are part of the "Gauss folklore" and probably go back to Gauss
himself".  The story is mentioned in passing in another endnote: "one of
the childhood stories ends with the pronouncement (in the local dialect)
"Dar licht se" with which the young Gauss handed in his solution of a
mathematical assignment.  Buehler's biography is very thorough...seems
he did not feel he had enough evidence to include the story.
-- 
Miguel Bamberger   | Mr Cooper's Law: "If you do not understand a particular
Austin Tech Pubs   | word in a piece of technical writing, ignore it.
                   | The piece will make perfect sense without it."
From: vorwald@oasys.dt.navy.mil (John Vorwald)
Newsgroups: sci.aeronautics
Subject: Popular Flight Control Simulators?
Date: 21 Aug 92 14:08:11 GMT
Reply-To: vorwald@oasys.dt.navy.mil (John Vorwald)
Organization: Carderock Division, NSWC, Bethesda, MD


  I am interested in identifying the different commericial
simulation/analysis packages that are available for analyzing
control systems.  I have
MATRIXx and Xanalog, and I have used MatLab, however, these packages
have size limitations (or support limitations) that limit the
pratical use (at least for the PC versions).

I would like to know
what packages are used for analyzing complex flight control systems
of aircraft (ie: Space Shuttle, V-22, F-16, F-18, RAH-66).

I have two particular products that I am trying to learn more about.
Does Boeing Computer Services sell a simulation package (and who
uses it), and if they do, what is Boeing Computer Service phone number?
And last of all, does anyone know about a package called
SimuLab, and who uses it and who sells it?

  All responses will be tabulated and a final summary of products will
be provided.


			    John Vorwald
From: berner@b-mrda.ca.boeing.com (Ann Berner)
Newsgroups: sci.aeronautics
Subject: 767 Ailerons and Manual Reversion
Date: 17 Aug 92 14:57:20 GMT
Organization: Boeing Commercial Airplanes MR&D


	There has been some discussion recently about manual reversion
and cable control of flight control surfaces vs. hydraulics, etc. Bob
Furtaw had seen some mention of "backup cables" relating to 767 ailerons.
The following may shed some light on the topic.

	Last week I finally got a chance to go look at my group's
(limited) stock of maintenance manuals.  Our copy for the '67 is UAL
767-222, and states clearly "no manual reversion" for ailerons.  This
was on the first page of the flight controls section.  However, I 
started getting confused when in the aileron section they started talking
about "backup cables".  Here I think is the key to the confusion.
Notice the following excerpt:

"The backup cables can be used as an alternate input path to control all three
LCCA inputs and/or right wing PCA inputs - dependent upon the nature of the
control system malfunction.  Alternate operation is accomplished through
"breakout" overrides and "arm-slot" lost motion devices.  An override is 
positioned at the juncture of each bus cable with its backup cable interface
(3 places)."  

The backup cables are all hooked up on the right side of the
airplane, so apparently you only get right aileron. Interesting to note,
isn't it, that a decision was made that cables binding up was a more likely
failure mode than total loss of hydraulics!

Also, just as some interesting info, the 757 has a "PCA override" right at 
the aileron.  It looks like it at least allows you to return the ailerons 
to a neutral position in case the PCA jams, but I don't think it actually 
gives you full control authority to move the ailerons directly with cables.


_____________________________________________________________________________
Ann Berner						Opinions expressed are
Boeing Commercial Airplanes				mine alone; I do not
berner@b-mrda.boeing.com				speak for Boeing.

--
From: hausslin@oasys.dt.navy.mil (Henry Haussling)
Newsgroups: sci.aeronautics
Subject: Re: CFD code required...
Date: 13 Aug 92 11:32:31 GMT
Reply-To: hausslin@oasys.dt.navy.mil (Henry Haussling)
Organization: Carderock Division, NSWC, Bethesda, MD

In sci.aeronautics, fortuna@cs.man.ac.uk (Armando Fortuna) writes:
>Hi netters,
>I am looking for a CFD code that does:
>
>o work with 3D incompressible flow

At CD,NSWC (David Taylor Model Basin) we have developed a set
(2D, axisymmetric and 3D) of CFD codes for incompressible flows.
They are for arbitrary geometries and have inviscid, laminar and
turbulent flow options.  Current users seem to find them relatively
easy to use.  If anyone is interested, I can provide more info.
From: flutter@vtcc1.cc.vt.edu (Lloyd Eldred)
Newsgroups: sci.aeronautics
Subject: Re: Interpolation routine for algebric grid
Date: 13 Aug 92 00:52:00 GMT
Distribution: usa
Organization: Virginia Tech, Blacksburg, Virginia
News-Software: VAX/VMS VNEWS 1.41

In article <23544@oasys.dt.navy.mil>, vorwald@oasys.dt.navy.mil (John Vorwald) writes...
>Hi
> 
>  I need to interpolate the output from a CFD code at locations that
>will be measured experimently.  The CFD grid is rather deformed, since
>it is shaped to the body.  The experimental values will be measured
>along stright lines perpendicular to the body.

   My current work is attempting to do something similar, although our
justification is different. We're doing aeroelastic modeling using
"black box" aerodynamic and structural codes. Our current work is to
devise a way of adequately representing the pressure field on the wing
with a minimum of data points. Basically we're trying to do an
optimal curve fit on our 2-D data field, where optimality requires both
a good fit and a low number of function coefficients.
   The first thing we attempted was a global (entire wing) fit using
Chebyshev polynomials as our functions. That worked, but had some problems.
The coeffiecients were overly sensitive to geometry changes (they wiggled)
and we felt we weren't capturing all of the nuances of the field.
(See Kapania, Eldred, & Barthelemy "Shape Sensitivity Analysis of Wing
Aeroelastic Response", 32nd SDM conference, Baltimore MD, to appear in
Jou. of Aircraft).

>  I can think of two ways to do this problem.  Search through the
>CFD geometry data to find the closest point.  Starting from the closest
>point, construct a "box" that encloses the point.  Then do linear
>interpolation to colaspe the "box" to a plane containing the point,
>followed by linear interpolation to colaspe the plane to a line
>containing the point, followed by linear interpolation to the point.

   We just completed work on the 2-D version of this approach. Our
local bi-linear scheme (as apposed to your tri-linear idea) does work very
nicely. We just sent off an abstract today with these results for next
April's SDM conference. 

>  The second method is to just find the N closest points (N ~ 8) and
>do a weighted averaged based on the distance to the point.

   This should be the same as your tri-linear scheme, I think.

   We're also planning to do constant pressure panels (just do a flat
average of the surround points) (This is coded and being analyzed at the
moment), biquadratic local fits, and a cubic local fit.

   So, a lot of things will work. The question is, what kind of performance
do you need from your scheme and how much effort do you want to put into it?
Do you have a good graphics/visualization capability to "see" if your
scheme is working the way you want? I initially had a problem with my
gridding not being dense enough in an area with a steep gradient in the
pressure. Looking at a color plot of the error helped me to fix my problem.

   I know this isn't exactly what you were looking for, but I hope it was
close enough to help.

-- Lloyd Eldred, Va. Tech
From: hausslin@oasys.dt.navy.mil (Henry Haussling)
Newsgroups: sci.aeronautics
Subject: Re: Axisymmetric Navier Stokes Equations
Date: 17 Aug 92 11:44:02 GMT
Reply-To: hausslin@oasys.dt.navy.mil (Henry Haussling)
Distribution: usa
Organization: Carderock Division, NSWC, Bethesda, MD

In sci.aeronautics, rfedkiw@crenshaw.math.ucla.edu (Ronald Fedkiw) writes:
>I'm trying to do a calculation of the full compressible Navier Stokes
>equations for flow past an axisymmetric blunt body.
>So, I put the equations into axisymmetric form and multiply
>through by 1/Jacobian = r = distance from centerline (of axisymmetry).
>I need to do this to put the equations back into conservative form for
>my method.
>The obvious problem is that the equations are no longer valid along
>the axis of symmetry (where r = 0). The Jacobian here is infinite.
>I'm not quite sure what the implications of an infinite Jacobian are,
>but from looking at my equations it becomes obvious that they cannot
>be used to solve the flowfield at r=0.
>
>I was wondering what sorts of methods ae in common practice to solve
>for the flowfield near r=0.

At David Taylor Model Basin we have had success using a finite-volume
method for obtaining solutions of the axisymmetric Navier-Stokes equations.
A cell-centered scheme is used.  Thus the computations are carried out at
points which may be near but are never on the axis of symmetry.  Boundary
conditions are applied through the use of a row of cells across the axis,
say at y=-r.
At the center of these cells the velocity normal to the axis is set eqaul
in magnitude but opposite in direction to the corresponding value at 
y=r.  The velocity tangential to the axis and the pressure at y=-r are set
eqaul to the values at y=r.  These conditions appropriately reflect the
axisymmetry.

With this approach we still have stability problems near the axis.  The
grid should not be any finer than necessary in this region.  We have found
it to be helpful to solve a modified set of equations where both the left-
and right-hand sides are multiplied by r.  Also, problems can be alleviated
by using a very small characteristic length for nondimensionalization.

Henry Haussling
From: clauter@oasys.dt.navy.mil (Carl Espen Lauter)
Newsgroups: sci.aeronautics
Subject: To all engineers
Date: 12 Aug 92 12:40:12 GMT
Reply-To: clauter@oasys.dt.navy.mil (Carl Espen Lauter)
Organization: Carderock Division, NSWC, Bethesda, MD


Thank you to everyone who responded to my request for help post.  I am
posting the message again so that anyone who may have missed it, and can
help will have the correct address to mail my friend.  I will be loosing
my account shortly and want to correct the address of the person you can
contact while I get an account at Virginia Tech.

REPOST:


To all engineers:

	Please contact Espen Lauter (senior at Virginia Tech,
Fall '92) if you can help provide information for a senior group
design project of an aircraft (type yet unknown).  We need
information on design, engines, hydralics, air conditioning,
on-board computers, navigation systems, airfoils, etc.  If you or
someone you know can provide this type of information as needed
during the project, please identify yourself with your name,
phone number, name of organization, location of organization, and
what component you have information available.  Any information
will be greatly appreciated.

	Please email:
			lynaugh@oasys.dt.navy.mil

I will no longer have an account here, but if you email lynaugh
he will forward my mail to Virginia Tech when I recieve a
computer account there.

Thanks in advance.

					Espen Lauter

P.S.  The previous post had the wrong email address for lynaugh.  The address
in this post is correct.
Newsgroups: sci.aeronautics