HDTenEightyP/NetNews huggingface dataset:
From: wesley.loewer@dwarp.sccsi.com (Wesley Loewer) 
Newsgroups: sci.fractals
Subject: Re: fractal foam algorith
Date: 11 Dec 92 17:45:00 GMT
Distribution: world
Organization: Data Warp Premium BBS - Spring/Houston, TX - 713-355-6107
Reply-To: wesley.loewer@dwarp.sccsi.com (Wesley Loewer) 

Looks like I'm a day late on posting this, but it still has some useful
information in it.  I just read Brian Hunt's posting with some very
interesting information concerning the fractal foam equations, so some of
this may be redundant.  Anyway, here's what I've come up with.

The 8 end points of the attractors are:
   A =  ( (-1 - 3*a^2)/4 , a/2 )   <-- consistent with Brian Hunt
   B = map(A)
   C = ((3*a^2 + 2*sqrt(3)*a + 1)/8 , (3*sqrt(3)*a^2 - 2*a + sqrt(3)/8)
   D = map(C)
   E = map(D)
   F = ((3*a^2 - 2*sqrt(3)*a + 1)/8 , (-3*sqrt(3)*a^2 - 2*a - sqrt(3)/8 )
   G = map(F)
   H = map(G)

To find the value of 'a' I set
    E = map(H) and H = map(E)
so that the gap between the attractors would be zero.  Using the equation
solver on my calculator, I found that there are four values of 'a' for
which this is true.

   a = +-1.02871376822  and  +-1.29099444874

The first pair of values is consistent with the article and with the
polynomial in Brain Hunt's post.

BH>77 - 33 a^2 - 9 a^4 - 27 a^6 = 0,

The second pair does not produce any inside basin, but does make an
interesting fractal when using a coloring scheme based on the number of
iterations before |z| gets bigger than some value (like the Mandelbrot
Set).

Happy Fractaling,
-Wes
==============================================================
  Wesley Loewer
  internet: loewer@star.harc.edu     telephone: (713)292-3449
           
Newsgroups: sci.fractals
From: kolombet@venus.iteb.serpukhov.su
Subject: What is the Fractal Universe?
Organization: Institute of Theoretical and Experimental Biophysics
Date: Fri, 18 Dec 1992 21:06:53 GMT

   Does anybody know what does the term 'Fractal Universe' mean?
Where can I read about it?
Xref: sparky sci.fractals:497 sci.math:17126 sci.edu:1246 misc.education:5388 k12.ed.math:1626
From: scavo@cie.uoregon.edu (Tom Scavo)
Newsgroups: sci.fractals,sci.math,sci.edu,misc.education,k12.ed.math
Subject: Lauwerier's works
Followup-To: sci.fractals
Date: 17 Dec 1992 23:17:39 GMT
Organization: University of Oregon Campus Information Exchange
Distribution: world
NNTP-Posting-Host: cie.uoregon.edu
Summary: info requested on Dutch works
Keywords: Lauwerier fractals

This is a re-post.  I'd really appreciate any and all pointers
to summaries and/or translations of these works.  Thanks.

---------------------------------------------------------------------
I've enjoyed Hans Lauwerier's _Fractals: Endlessly Repeated
Geometrical Figures_ (Princeton Univ. Press, 1991; originally
published in Dutch by Aramith Uitgevers, Bloemendaal, 1987)
off and on the last year, and I was hoping someone could tell
me more about a couple of references he gives therein.

   Lauwerier, H.A.  _Analyse met de microcomputer_.  Epsilon
   uitgaven, 1987.

   Lauwerier, H.A.  _Meetkunde met de microcomputer_.  Epsilon
   uitgaven, 1987.

At the risk of making a foolish mistake, I'll guess that these
titles translate into _Analysis with the Microcomputer_ and
_Geometry with the Microcomputer_, respectively.  Of these works,
Lauwerier says

   These volumes are aimed at use in schools.  The emphasis
   is on making graphic representations, tracing figures in
   the plane, and projections of spatial bodies.

My questions are:

1) Would someone care to comment on the content of these texts?

2) Have these texts been used in Dutch schools, and if so, with
what success?

3) Do English translations exist?

Thanks in advance,
-- 
Tom Scavo
scavo@cie.uoregon.edu
Newsgroups: sci.fractals
From: noring@netcom.com (Jon Noring)
Subject: Some Preliminary Comparisons  (was Re: How much faster?)
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Wed, 16 Dec 1992 17:32:35 GMT

In article mrmarcel@eos.ncsu.edu (Mike Marcelais) writes:
>In article noring@netcom.com (Jon Noring) writes:

>>I currently have a 386-33 pc with a Cyrix math coprocessor.  What I'd
>>like to know is how much faster would a 486-50 or 486-66 be when
>>calculating fractals using Fractint 17.2 (and for both integer and
>>floating point modes).

>Here's some benchmark times for fractint 17.2
>System:  486/50dx, 256K cache, 4M memory, DR-Dos 6.0
>         Tseng-4000 SVGA with Local Bus
>
>All options left at default settings, except where noted.
>
>Mandelbrot set:     1024x768x256
>floating point off       6.97
>floating point on        8.85


For my 386-33, it took 13.29 seconds for the 1024x768x256 FPU off, and
24.99 seconds for the FPU on.


>Plasma file, 1024x768x256, seed 42
>    Old method    22.19
>    New method    19.34

It took 57.34 seconds for the old, 51.03 for the new.


>Lypanov type, 320x200x256
>    Order  0   3:16.46

It took 9:11.35 for this one.


>Julibrot type, all defaults
>   320x200x256   3:30.31

It took 6:41 for this one.



Conclusion, the 486-50 was *approximately* 2 to 3 times faster in calculating
these fractals.  I would expect the 486-66 to be 10 to 20% faster than the
486-50.

Jon Noring



-- 

Charter Member of the INFJ Club.

Now, if you're just dying to know what INFJ stands for, be brave, e-mail me,
and I'll send you some information.  It WILL be worth the inquiry, I think.

=============================================================================
| Jon Noring          | noring@netcom.com        | I VOTED FOR PEROT IN '92 |
| JKN International   | IP    : 192.100.81.100   | Support UNITED WE STAND! |
| 1312 Carlton Place  | Phone : (510) 294-8153   | "The dogs bark, but the  |
| Livermore, CA 94550 | V-Mail: (510) 417-4101   |  caravan moves on."      |
=============================================================================
Who are you?  Read alt.psychology.personality!  That's where the action is.
Newsgroups: sci.fractals
From: rr@sco.COM (Renaldo Recuerdo)
Subject: Re: phase space
Organization: The Santa Cruz Operation, Inc.
Date: Tue, 15 Dec 1992 16:33:03 GMT


mroussel@alchemy.chem.utoronto.ca (Marc Roussel) writes:

|P.S., to Hany:  There is no such newsgroup as sci.chaos so I'm posting
|this to sci.fractals.
=======================================================================
Well, for a non-existent newsgroup it sure has had an interesting thread
lateley (does the atmosphere exhibit chaotic behaviour, what's the difference
between chaos and turbulence, how best to model atmospheric turbulence, ...).
I know it doesn't exist, but i read it anyway.
-rr-
-- 
TOKYO, JAPAN, 1991 JUL 3 (NB) -- Chaos technology builds upon the fuzzy logic
concept by applying "chaotic" principles to data. As the word implies, chaos 
is a state where no rules apply. Yet the theory of probability dictates that, 
if enough situations are created, then an order of logic will apply.
Xref: sparky sci.fractals:493 sci.chaos:26 comp.theory.dynamic-sys:380
From: hkhatuya@sdcc3.ucsd.edu (Haripada Khatuya )
Newsgroups: sci.fractals,sci.chaos,comp.theory.dynamic-sys
Subject: What is meant by the lack of a Characteristic scale?
Date: 17 Dec 92 02:31:28 GMT
Followup-To: sci.fractals
Organization: University of California, San Diego

My question concerns the application of Multi-resolution stochastic
processes in the area of signal processing.  
Most of the papers say this kind of analysis is
useful for signals where there is no one single characteristic
scale.

o What exactly IS meant by a time series of signals having no
characteristic scale?  
o Does the lack of a unique characteristic scale imply the
non-existence of statistical moments?
o Is there any body of statistical theory existent to detect 
the presence or absence of mutliple scales?
o Is it true that multiplicity of scales imply signals 
with power-law (as opposed to exponential) correlation decay?
 
I know that the issues of long-range range dependence (slow decay of
correlations), 1/f noise, self-similarity, fractal supports, non-analytic
distributions, power laws, wavelets, multi-resolution stochastic
processes etc., are interlinked, but I haven't been able to find any
rigorous (especially in terms of statistical theoretic models)
links.  For eg., Multi-fractal measures are now widely used in
Physics, but I have yet to see them in any journal of statistics.
There have been many journal articles on the application of Chaos
theory to statistical analysis, but all of these concentrate on
invariants like dimension and Lyapunov exponent estimates.  I have
seen NOT ONE article on the consequences on standard statistical tests
and estimation procedures of substituting ,say, fractal spaces for
the standard sample spaces of classical probability analyses. 

Also, can anybody expound on the link of the new theory of Self
Organised Criticality to the presence of multiple scales,if any at
all exist?  Does the SOC model imply that the lack of a
characteristic scale causes a breakdown of the traditional concept
of "Causality", ie., a given input causes a definite response in
output?  This is beginning to sound wrong, but I'd still love to
hear more on this. 

Any leads, clues, explanations, pointers, papers, references, etc.
highly appreciated.  Sorry about the long rather rambling post.

Hari.
Newsgroups: sci.fractals
From: tola@jyu.fi (Teemu Lahteenmaki)
Subject: Sofware for measuring fractal dimension ?
Organization: University of Jyvaskyla, Finland
Date: Mon, 14 Dec 1992 12:25:03 GMT

Does anyone know is there any software availble for measuring fractal
dimension ? The analyzis would be done from digitized images. As the
images can have meny gray-scales it would be useful to have some kind of
contrast-option.. 
Any sources would be appreciated.



-- 
____________________________________________________________
I  Teemu Lahteenmaki - student of mathematical computing   I
I  Intergalactical University of Jyvaskyla, Finland        I
I_ tola@jyu.fi ___________ 25 30'32" East 62 37'59" North _I
Newsgroups: sci.fractals
From: rms@cs.tu-berlin.de (Michael R. Ganss)
Subject: Fractal Witchcraft speed?
Organization: Technical University of Berlin, Germany
Date: Wed, 16 Dec 1992 13:57:08 GMT

Does anyone out there know how FractalWitchcraft achieves its speed?
I was completely stunned at the time it took FW to generate the example
image (Lightning...) in comparison to Fractint 17.2 with no floating point
and guessing:
Fractint 17.2: ca. 2h15min
FW: 	       ca. 20sec   
(486-33)

I've figured that FW's speed cannot result from the way it builds up the
screen. First of all, there is nearly no difference between edge tracing on
and off. Also, I believe the little pseudo-tesseral thing it does can't be
credited for the speed (it doesn't even recognize larger areas of single 
color). I think FW must have some speedup in the core iteration loop, mainly
because it seems nearly unaffected by iteration limit variations.
Anybody got more info?

Thanks
--
Michael R. Ganss         B: Cup or cone?
rms@cs.tu-berlin.de      A: Cone. I like to lick.
From: dancer@ccwf.cc.utexas.edu (Donn Chambers)
Newsgroups: sci.fractals
Subject: Fractal modeling of Ocean Topography
Date: 14 Dec 92 20:16:17 GMT
Organization: CyberPagans and Misc. Lost Souls of the South

Hello,

I am seeking help in some studies I am conducting.  I am looking for 
any good sources which offer any sort of explanation on deriving 
a fractal model from a data set (say,ocean heights).  In particular, I
would appreciate any one out there in Austin who has some experience
with this to drop me line.  So far, I haven't found anyone directly
associated with the math or physics departments at UT who work 
with fractal modeling.

Thanks,
Donn Chambers
-- 
*******************************************************************************
SATOR            The creator      | "I once was a dancer, young once like you
AREPO            slow moving      |   though I know I don't look it
TENET             perceives       |  I jumped as high as the sky, I had fire
OPERA           his creations     |   in my eyes, I had legs like a stallion."
ROTAS            as vortices      | -- David & David, "Swallowed by the Cracks"
From: edgar@function.mps.ohio-state.edu (Gerald Edgar)
Newsgroups: sci.fractals
Subject: Re: L-Systems (3d example sought)
Date: 14 Dec 1992 08:38:28 -0500
Organization: The Ohio State University, Dept. of Math.
Distribution: usa
NNTP-Posting-Host: function.mps.ohio-state.edu


There is a 3d curve in Chapter 9 of my book _Measure, Topology, and
Fractal Geometry_.  It is given in Logo notation, rather than L-system
notation, but that difference is unimportant.
-- 
  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)
From: scavo@cie.uoregon.edu (Tom Scavo)
Newsgroups: sci.fractals
Subject: Re: Dimension of Mandelbrot border
Date: 17 Dec 1992 22:05:08 GMT
Organization: University of Oregon Campus Information Exchange
NNTP-Posting-Host: cie.uoregon.edu
Summary: preprint is in the Stony Brook archive

In article <19362.2b3094ac@ecs.umass.edu> diamond@ecs.umass.edu writes:
>I have heard that there has been a recent proof that the
>dimension of the boundary of the quadratic Mandelbot set (Zn+1 =
>Zn^2 + C) is two.  I would like references and perhaps even a 
>short description of the proof.  Either post on sci.fractals or 
>send me mail.  Of course, if I heard wrong, feel free to ignore, 
>chastise, etc.

You heard right.  A preprint of Shishikura's paper can be obtained
by anonymous ftp from math.sunysb.edu in the directory preprints.
The particular one that you're looking for is

ims91-7
   Author:   M. Shishikura
   Title:    The Hausdorff Dimension of the Boundary of the Mandelbrot Set
             and Julia Sets.
   Abstract: It is shown that the boundary of the Mandelbrot set $M$ has
             Hausdorff dimension two and that for a generic $c \in \bM$, the
             Julia set of $z \mapsto z^2+c$ also has  Hausdorff dimension
             two.  The proof is based on the study of the bifurcation of
             parabolic periodic points.
   Format:   AmSTeX, with both PostScript figures and Sun Rasterfile
             pictures.  Requires psfig for figures.

The archive at Stony Brook can also be accessed by e-mail:

	send the message
 		send ims91-7 from preprints
	to preprints@math.sunysb.edu to retrieve the file

There's a ton of good stuff to be found here, but some familiarity
with TeX and PostScript will be necessary to process the files.

-- 
Tom Scavo
scavo@cie.uoregon.edu
From: v071r4mh@ubvmsb.cc.buffalo.edu (CHRISTOPHER D. KOZINA)
Newsgroups: sci.materials
Subject: piezoelectric composites
Date: 19 Dec 92 21:06:00 GMT
Organization: University at Buffalo
News-Software: VAX/VMS VNEWS 1.41

I was wondering if anyone had information on piezoelectric composites 
with high d .g especially PZT-composites, PbTiO , and Nb based piezo electrics
           h  h                                3
i know ive posted about general piezoelectrics before but now im doing my thesis
on composite piezoeletrics
geometric set-ups would be great also thanks
brett
lembke@ceramics
lembke@bigvax.alfred.edu
From: msk9@po.CWRU.Edu (Mahesh S. Khot)
Newsgroups: sci.materials
Subject: Re: References on  ferrofluids
Date: 14 Dec 1992 01:32:03 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: msk9@po.CWRU.Edu (Mahesh S. Khot)
NNTP-Posting-Host: slc5.ins.cwru.edu


In a previous article, me@hamilton.eecs.umich.edu (My Account) says:

>>What you are refering to here is more likely ferrofluids.
>>Electrorheological fluids use electric fields instead of magnetic fields
>>
>>M. Block and J.P. Kelly, "Electro-rheology review article", J. Phys. D:
>>Appl Phys. vol 21, Dec 14, 1988, p. 1661-1677.
>>
>
>Hi everyone,
>
>I looked in several  Physics Journals in order to obtain some 
>articles about this ferrofluids,
>or  materials that harden/soften with applied magnetic field.
>Unfortunately I did nut sucesseed.
>
>I would greatly appreciate any references or pointer.
>
>M. BOUZIT   
>mbouzit@robo.jussieu.fr
>Robotics Lab of Paris
>Universite Piere et Marie Currie
>FRANCE
>
>
>

If Electrorheological Fluids is what you're looking for or something
similar to that there is an article in recent issue of Science, with 34
references.  That should give you a start.
Citation:
Title:		Electrorheological Fluids
Author:		Thomas C. Halsey
Source:		Science Vol 258, 30th October 1992, 761-766. 

Mahesh
-- 
The King of Queen (rock group) is dead / But their music still lingers.
euphemism:  famous dummies =  Madam Tussade's Wax Museum. 
Still at Case msk9@po.cwru.edu
Newsgroups: sci.materials
From: boswell@fnalh.fnal.gov (Chris Boswell JHU CDF (708)840-3638)
Subject: information wanted on cubic zirconia
News-Software: VAX/VMS VNEWS 1.4-a4  
Keywords:  cubic zirconia
Reply-To: boswell@fnalh.fnal.gov
Organization: Fermilab
Distribution:  world
Date: Sat, 19 Dec 1992 23:07:37 GMT


Hello,
  I am working with silicon diode particle detectors, and know
of some work with diamond, which is hard to make into a detector
because a single crystal is more efficient, whereas the depositio
diamond traps charge at the crystal boundaries.  This got
me thinking:  what are the electrical properties
of cubic zirconia, and how is it made?  If you know
where to look, I would appreciate the info.

	Chris Boswell
From: laurent@kaa (Laurent Fulchieri)
Newsgroups: sci.materials
Subject: C 60 TRUNKATED ICOSAEDRAL COORDINATES
Keywords: COORDINATES
Date: 17 Dec 92 12:13:02 GMT
Reply-To: laurent@cenerg.cma.f
X-Newsreader: Tin 1.1 PL4

Because I am a bad mathematecian and especialy a lazy,
I am looking for trunkated icosaedral coordinates 
(as C 60 ) to vizualize the structure on a display. 

Newsgroups: sci.materials
From: brantley@infonode.ingr.com (Dwight D. Brantley)
Subject: identifying polymer cross linking
Organization: Intergraph Corporation, Huntsville, AL.
Distribution: usa
Date: Tue, 15 Dec 1992 22:41:00 GMT

I have been experimenting with determining the integrity of cross linked
polymers.  So far I have exposing my samples in an oxygen rich plasma etch
for 10 minutes then analyzing the sample in a SEM.  I think we are seeing
that examples of proper or "good" cross linked polymers show a grain of
structure of uniform size and orientation while the "bad" samples seem
to display a wide variation of grain size over a given area.  Is this a
viable method of analyzing such materials?  Can anyone add anything to
this?  I am not very familiar with such materials so consider me mostly
ignorant on this subject.  Any information (in simple terms) would be of
great help.

Thanks,

      ******************************************************************
      *   Dwight Brantley    *   Failure Analysis & Reliability Dept.  *
      *  Intergraph, Corp.   *  Reply To: brantley@falab1.b21.ingr.com *
      *   Huntsville, AL     *           Voice: 205-730-4456           *
      ******************************************************************
From: 5916rahmank@vms.csd.mu.edu (K. M. A. Rahman)
Newsgroups: sci.materials
Subject: Re: Why some materials you can see through?
Date: 18 Dec 1992 05:11:50 GMT
Organization: Department of EECE, Marquette University
Distribution: na
Reply-To: 5916rahmank@vms.csd.mu.edu
NNTP-Posting-Host: vmsf.csd.mu.edu

In article <1992Dec17.192957.1189@ptdcs2.intel.com>, greason@ptdcs2.intel.com (Jeff Greason ~) writes:
->In the same "hinting" tone of this thread, let me "hint" the following:
->
->How is the conductivity of a material related to it's transparency to 
->radio waves?  What's the difference between radio waves and light waves?
->
->Disclaimer:  All opinions expressed are my own, and do not reflect the 
->     position of Intel, Portland State University, or Zippy the Pinhead.  
->============================================================================
->Jeff Greason                  "You lock the door ... And throw away the key.
->  <greason@ptdcs2.intel.com>   There's someone in my head, but it's not me."
->  <jeffg@eecs.ee.pdx.edu>				-- Pink Floyd
->

	My brain is really burnt out doing piles of other things. Would
	you please explain despite hi(n)ting on my brain (:-)?

	-Anis.
Newsgroups: sci.materials
From: me@hamilton.eecs.umich.edu (My Account)
Subject: References on  ferrofluids
Organization: University of Michigan EECS Dept., Ann Arbor, MI
Date: Sat, 12 Dec 1992 16:32:54 GMT


>In article <BxxsAw.Kq7@aplcenmp.apl.jhu.edu> doherty@aplcenmp.apl.jhu.edu  
(Kevin
> Doherty) writes:
>>esm40@cd.amdahl.com (Ed McGettigan) writes:
>>
>>>Does anyone know of any materials/liquids that harden when you apply
>>>a voltage/current to them and revert when you turn it off?
>>
>>  Think there's a whole family of such materials-called (I believe)
>>electrorheologic materials.

>That's true but.....
>>
>>  The ones I've heard of tend to be used in magnetic clutches and the
>>like.  They consist of thick oils loaded with powdered steel-under the
>>influence of a magnetic field the material 'solidifies' (the powder
>>consolidates).  The stuff would likely behave the same if you ran a
>>current thru it (because of the resulting magnetic field).  No problem
>>that it's an insulator-one variety of this stuff uses mercury as a
>>matrix.
>
>What you are refering to here is more likely ferrofluids.
>Electrorheological fluids use electric fields instead of magnetic fields
>and the particles are suspended in a dielectric fluid and are themselves
>dielectrics.  The idea is that the particles become polarized upon
>application of the electric field and form long chains.  These chains
>cause a substantial increase in the viscosity of the fluid.  For a good
>all round review of the field of electrorheological fluids check out:
>
>M. Block and J.P. Kelly, "Electro-rheology review article", J. Phys. D:
>Appl Phys. vol 21, Dec 14, 1988, p. 1661-1677.
>
>Hope this helps,
>
>Kent Goeking
>Creare Inc.
>kwg@creare.com
>
>


Hi everyone,

I looked in several  Physics Journals in order to obtain some 
articles about this ferrofluids,
or  materials that harden/soften with applied magnetic field.
Unfortunately I did nut sucesseed.

I would greatly appreciate any references or pointer.

M. BOUZIT   
mbouzit@robo.jussieu.fr
Robotics Lab of Paris
Universite Piere et Marie Currie
FRANCE
From: craigen@ace.acadiau.ca (DOUGLAS CRAIGEN)
Newsgroups: sci.materials
Subject: Re: Looking for materials with the properties of...
Date: 18 Dec 92 19:56:53 GMT
Organization: Acadia University

In article <BzGt7w.5nu@neon.rain.com> chris@neon.rain.com (Chris Perez) writes:
>From: chris@neon.rain.com (Chris Perez)
>Subject: Looking for materials with the properties of...
>Date: Fri, 18 Dec 1992 17:14:18 GMT
>I'm looking for materials that have the following properties:
>
>	- Pressure/electrically sensitive
>	- Optically detectable contact points
>	- Erasable image (somehow) 
>
>Hints?  Suggestions of where to search? 
>
>Christopher Perez - chris@neon.rain.com
>"Do NOT use this brain.  Abnormal."  The warning Igor ignored...
>
   It isn't clear exactly what you are looking for.  You may find something 
of interest in "electrochromic" materials.  These are used in 
electrochemical devices and have the property of changing color according to 
the applied voltage.  Typically they respond in times of the order of 
seconds, and may be cycled 100,000 times.

===================================================================
  Doug Craigen, Department of Physics, Acadia University,
  Wolfville, N.S., B0P 1X0, (902) 542 - 2201 x150

  FOR RENT - signature file space
             (reasonable rates)
Newsgroups: sci.materials
From: chris@neon.rain.com (Chris Perez)
Subject: Looking for materials with the properties of...
Date: Fri, 18 Dec 1992 17:14:18 GMT

I'm looking for materials that have the following properties:

	- Pressure/electrically sensitive
	- Optically detectable contact points
	- Erasable image (somehow) 

Hints?  Suggestions of where to search? 

Christopher Perez - chris@neon.rain.com
"Do NOT use this brain.  Abnormal."  The warning Igor ignored...