HDTenEightyP/NetNews huggingface dataset:
From: shanks@saifr00.cfsat.honeywell.com (Mark Shanks)
Newsgroups: comp.human-factors
Subject: Re: I can't take this anymore
Date: 2 Sep 92 18:10:16 GMT
Organization: Honeywell Air Transport Systems Division

In article <1992Sep2.155522.5333@sbctri.sbc.com> asper@sbctri.sbc.com (Alan E. Asper) writes:
>When I subscribed to comp.human-factors, I believed I would be getting into
>some actual dialogs about human factors research. I thought I would 
>_learn_ something.
>
>Instead, what I find are sweaty, arrogant computer programmers who (ooooh!)
>read the Apple styleguide and (aaaah!) are members of Don Norman's growing
>cult of personality. No data, no research, just baseless opinions and a 
>conviction that "since I think it is so, and I have worked with these systems,
>it is so. And I read POET, so shut up." If I read one more misuse of the term 
>"affordance", I'm going to hurl.
>
>So please, if you must go back and forth about your useless notions, create a 
>newsgroup called comp.talk.out-of-your-ass. Otherwise, leave this newsgroup
>to those who have a genuine interest. 

AMEN! As the original respondent to Tom Christiansen's amazing hissy-fit,
I thought the subject would perish under it's own pomposity. Instead,
we're getting advice on where to set our coffee cups on our desks. I 
sincerely doubt if most of the responders have ever worked a day as a
human factors engineer, or if they have, I pity their clients. Thank you,
Alan.
_____________________________________________________________________________
Mark Shanks
Principal Engineer, 777 Displays
_____________________________________________________________________________
Newsgroups: comp.human-factors
From: raveling@Unify.com (Paul Raveling)
Subject: Re: Knobs are better than sliders
Organization: Unify Corporation (Sacramento)
Date: Thu, 27 Aug 92 20:20:07 GMT

In article <s0D5PB2w165w@mantis.co.uk>, jonathan@mantis.co.uk (Jonathan Egre') writes:
> esr@snark.thyrsus.com (Eric S. Raymond) writes:
> 
> > Proposed: Knobs are better than sliders
> > 
> > Argument: Human beings have much better control of (and proprioceptive memory
> > for) wrist rotations than they do for arm movements.  (My girlfriend contribu
> > the guess that the evolutionary reason for this is probably specialization
> > for precise throwing ability.  ...

	My guess for cause would be ability to manipulate a large variety
	of things that become food, shelter, and tools.  I'm sure chucking
	spears and rocks at animals contributed to our motor skill evolution,
	but would guess that construction was the main driver for skills
	of precision.

	A related guess is that finger motion is important.  An example
	is the two different grips that we still use on screwdrivers:
	A finger-tip grip for fine motion, and a whole-hand power grip for
	applying force with much less precision through the arm and wrist.

	At least one early-model mouse offered rotation sensing
	as well as translation; I'd be delighted to see that as a
	standard feature to drive knobs in a GUI interface.


------------------
Paul Raveling
Raveling@Unify.com

Newsgroups: comp.human-factors
From: jaime_guerrero@afs.com
Subject: Re: Knobs are better than sliders
Reply-To: jaime_guerrero@afs.com
Date: Thu, 27 Aug 1992 18:14:16 GMT

In article <1hZ33V#82f0tg2jvsRT1BGbkM9jBSCw=esr@snark.thyrsus.com>  
esr@snark.thyrsus.com (Eric S. Raymond) writes:
|  ...
|  Proposed: Knobs are better than sliders
|  ...

Agreed!  I did some research a few years ago on user interfaces suitable for  
the most technically illiterate, and settled on using knobs.  Not 270 degree  
potentiometers like on your radio, but free-spinning digital knobs like on HP  
digital occiliscopes and many new ovens.  (In the case of the occilliscope, a  
knob and 5 buttons greatly simplifies a complex instrument, and in the case of  
the ovens, a knob is less customer-hostile than a multibutton microwave-like  
keypad.)  The knobs use incremental encoders, just like those inside a mouse,  
and can detect accelleration to improve feel.

My inspiration for the knobs idea was the extremely satisfying feel of  
flywheel tuners on old nondigital radio receivers.  Also, keyboards, mice, and  
touch screens are not viable in factory-floor industrial environments, while  
knobs are routinely made indestructible, water/explosion-proof, and are quite  
usable with gloves on.

Also, as anyone who has tried to execute a smooth fade using an audio mixer  
with slide potentiometers or adjust a slide volume or temperature control in a  
moving vehicle can attest, knobs beat sliders!  It is difficult to brace the  
other fingers or hand such that a slider can be moved smoothly and precisely.   
It is easier to adjust a knob because (1) the arm is supported by the knob  
bearings, (2) the hand rotator muscles are not being used for supporting the  
arm and so a free to precisely control the knob, and (3) the body is usually  
not rotating significantly in relation to the knob.

Witness the trend in American automobiles away from slide temperature and fan  
controls toward rotary knobs.

A bank of sliders (on a mixer, for example) CAN do one thing that can't be  
done with a bank of knobs- move (fade out) several channels simultaneously,  
which is difficult to do well but CAN be done, by pushing the sliders with  
individual fingers, the edge of the hand, or a flat object.

--
Jaime F. Guerrero                              "How well do we use
Anderson Financial Systems, Inc.                The freedom to choose
Springhouse, PA, USA                            The illusions we create?"
jaime@afs.com          [NeXTmail accepted]      -Timbuk 3
Newsgroups: comp.human-factors
From: instone@hydra.bgsu.edu (Keith Instone)
Subject: Re: monitors vs paper
Organization: Bowling Green State University, Computer Science
Date: Thu, 27 Aug 1992 14:26:54 GMT

 tomf@cs.man.ac.uk (Tom Franklin) writes:
|> Can anyone provide me with information or references about the comparative
|> ease and speed of reading text from monitors and paper.

The most comprehensive review that I have seen on this topic is:

  "Reading from paper versus screens: a critical review of
   the empirical literature" 
   by Andrew Dillon of HUSAT Research Institute

The 30 page article was just published in "Ergonomics." Look for the
most recent issue, vol 35 # 10, October 1992.

Keith instone@hydra.bgsu.edu
Newsgroups: comp.human-factors
From: oegaard@itk.unit.no (Ommund Oegaard)
Subject: MS Windows GUI
Organization: Norwegian Institute of Technology / SINTEF, Trondheim, Norway
Date: 3 Sep 92 10:53:57


I am currently comparing the style guides for OSF/Motif, OPEN LOOK UI, Apple
Desktop and MS Windows. I have the official style guide definitions for the
first three, but my bookstore is unable to find such a thing for MS
Windows. What is the title and ISBN number for the document defining the MS
Windows GUI?



 
--

Regards, Ommund Oegaard

SINTEF Automatic Control                : Phone +47 7 594375
The Norwegian Institute of Technology	: Fax   +47 7 594399
N-7034 Trondheim                        : Email oegaard@itk.unit.no
NORWAY

Newsgroups: comp.human-factors
From: ransom@monu6.cc.monash.edu.au (Mr S. Ransom)
Subject: Re: Knobs are better than sliders
Organization: Monash University, Melb., Australia.
Date: Thu, 27 Aug 1992 05:52:52 GMT
Expires: Sun, 13 Sep 1992 14:00:00 GMT

In article <1hZ33V#82f0tg2jvsRT1BGbkM9jBSCw=esr@snark.thyrsus.com> esr@snark.thyrsus.com (Eric S. Raymond) writes:

>I was in the shower with my girlfriend this morning, and happened to be in
>a Zenlike notice-everything mood when she adjusted the water temperature.
>                              ...
>Proposed: Knobs are better than sliders


This is my first (ever) post so standard disclaimers apply.

I'm fascinated by the concept (and jealous of the source :-) ).

From a perfunctory chat with the nearest hardware person it seems that
the mouse has three internal sensors for tracking the movement of the 
ball so the raw data is available to determine rotation.  I was also 
told that the mouse movement data ultimately delivered by the driver 
is limited to XY coordinate changes.  

Now in order to do this either the mouse itself or (more likely) the 
driver has to be stripping the rotational information out of the data 
delivered by the three sensors.

Can anyone comment as to where this mapping occurs and, if it is in 
the driver, are there any standards (and drivers) which do extract and 
deliver the rotational data?

Also, it would seem that a large diameter (say 5cm or so) trackball 
would be more useful than a mouse for this.  I use only my wrist to 
control a mouse but need my fingers and wrist to turn a tap with any 
sort of fine control (I lock my fingers if the tap is sticking and I 
need brute force).
-- 
Stephen Ransom                        | Department of Software Development
Telnet: ransom@monu6.cc.monash.edu.au | Monash University
Phone: (613) 573 2181                 | Australia
Newsgroups: comp.theory
From: gupta@nmsu.edu (Gopal Gupta)
Subject: A question
Organization: NMSU Computer Science
Date: Thu, 3 Sep 1992 22:51:09 GMT


Can anyone help me with the following problem. An actual
proof or a reference to a paper where I can find the proof
will be most helpful. Thanks.

Consider the following sequential program:

        begin
                (1) input a finite set of integers S;
                (2) find an x in S such that some fixed property P(x) is true;
                (3) output x
        end.

        Question:  Can the search in step 2 be done in number of steps
                independent of the size of S?   If so, how?  If not, how do
                you prove it?    (Ignore time to compute P(x).)


Please reply by email, as I don't read this newsgroup often.

Thank you.

Gopal Gupta
---------------------------------------------------------------------
Department of Computer Science	   email: gupta@nmsu.edu
Box 30001, Dept. CS		      	  gupta@compsci.bristol.ac.uk
New Mexico State University	   Ph: +1 (505) 646 6236 
Las Cruces, NM 88003-0001	   Fax: +1 (505) 646 6218
USA
---------------------------------------------------------------------

	 
Newsgroups: comp.theory
From: abrodnik@watdragon.uwaterloo.ca
Subject: Re: Generic sorting functions
Organization: University of Waterloo
Date: Mon, 24 Aug 1992 02:06:24 GMT

In article <9208212151.AA44579@cs90code.csv-tgsc.amex-trs.com> gonzalod@amex-trs.com (Gonzalo Diethelm) writes:
>
>A very generic question. Given a set S of n strings (the `|' characters
>are used as delimiters):
>
>  s1   |dunno|
>  s2   |I'd rather have a bottle in front of me than a frontal lobotomy|
>  s3   |eschew clever rules|
>  ... ...
>  sn   |bzzzzt!|
>
>and an ordering sequence O:
>
>  {s4, s1, s6, s2, sn, s3, ... s7}
>
>is there any way to determine a fixed, hopefully cheap function
>
>  f(): SxS -> integers
>
>with the property that
>
>  if si comes before sj in O, f(si, sj) < 0
>  if si comes after  sj in O, f(si, sj) > 0
>
>that is, could be used to sort the strings in the given sequence?

If I understnd this correctly, you are asking the following question:

	o you are given a total ordering (not known how to efectively
	  compute relations among elements)
	o make a comparison function for this ordering.

If your function can use O(S) space, your total running time is 

			    O(S*c + n*c),

where n is the number of queries to it. The c represents the time to
fetch the internal table.

At first query f simply runs through the sequence O until it finds the
right key (it can't do better -- apply a simple adversay argument,
because you don't know efective function to describe it). As it
searches for the right key, it assigns proper indices to the internal
table. This table will be later used to map from key --> itsOrder. The
assumption here is that the set of keys {s_i} is known in advance.

Each searching for the index in the table takes O(c) time (you can
take here O(log S) for tree or binary search, or O(1) for perfect
hashing).

The first search takes O(S*c) time, but each subsequent search will
take then O(c) time what gives us the above bound.

Even more, because of the adversary argument the lower bound on the
first search is also _O_(S*c) and simple reasoning will also show that
the mentioned upper bound matches the lower bound.

The overall assumption here is that the set {s_i | i=1..S} is known in
advance. I think that it is feasible especially because the only way
to order elements is through the sequence O. It's an interresting
question if the space can be decreased. Again (because of the
adversary argument) it seems that the time will increase immediately.

This are my 2 pence.

Best regards,

Andrej
Newsgroups: comp.theory.self-org-sys
From: cscc13@judy.uh.edu (NAVEED IQBAL)
Subject: Transputers
News-Software: VAX/VMS VNEWS 1.41    
Organization: University of Houston
Date: Mon, 31 Aug 1992 22:43:00 GMT

	Anyonw know what the transputers are and who is
using them. Is there a new programming paradigm for parellel
processing or the current languages are serving the purpose.

Thanx 
Naveed Iqbal
NIqbal@uh.edu
From: jmount+@CS.CMU.EDU (John Mount)
Newsgroups: comp.theory
Subject: Re: Is this problem NP-complete?
Date: 25 Aug 92 21:27:37 GMT
Article-I.D.: cs.BtK6A4.HzL.2
Followup-To: comp.theory
Organization: Carnegie Mellon University

In article <1992Aug25.185050.11956@watson.ibm.com>, raghu@norway.fishkill.ibm.com (Raghu Hudli) writes:
|> The problem is given a weighted graph G = (V,E) with positive weights
|> for all edges in E, the weight of a vertex v_i in V is defined as the
|> sum of the weights of edges incident on v_i. Find a subset S of V, such
|> that |S| = K and the graph G' = ((V-S), E') has no vertex whose weight 
|> is greater than a constant T. E' is  E - edges incident on vertices in S.
|> 
|> I have heuristic solutions for the problem that seem to work well. I wanted
|> to make sure that I was not missing the optimum solution if the problem were
|> not NP-complete. 

This problem is NP complete.  This is easy to see by reducing from the
Independent Set problem (Garey and Johnson "Computers and
Intractability": given G = (V,E) and N, find a subset S of V such that
|S| = N and the induced subgraph has no edges), just set all the edges
to be weight 1, T = 0 and K = |V| - N.

|> Thanks in advance for your response.
|> 
|> Raghu Hudli
|> -----------------------------------------------------------------------
|> Raghu V. Hudli                       Tel:   (914) 892-4188
|> IBM Corporation                      Fax:   (914) 892-4316 
|> E. Fishkill, NY                      email: raghu@vnet.ibm.com
|> ------------------------------------------------------------------------
|> Disclaimer: The opinions/views expressed here are mine and my employer
|> does not necessarily concur with me.

-- 
--- It is kind of strange being in CS theory, given computers really do exist.
John Mount: jmount+@cs.cmu.edu               (412)268-6247
School of Computer Science, Carnegie Mellon University, 
5000 Forbes Ave., Pittsburgh PA 15213-3891
Newsgroups: comp.theory
From: litow@csd4.csd.uwm.edu (Bruce E Litow)
Subject: complexity of rational function integration
Originator: litow@csd4.csd.uwm.edu
Keywords: parallel complexity, definite integrals, rational functions
Organization: Computing Services Division, University of Wisconsin - Milwaukee
Date: Fri, 4 Sep 1992 13:32:36 GMT

I would like references to work on parallel complexity of approximating
definite integrals of rational functions, especially methods that do
not involve finding the roots of the denominator.

-- 
Bruce Litow
Computing Services Division
P.O.Box 413, University of Wisconsin-Milwaukee, 53201
414 229 6431    litow@csd4.csd.uwm.edu
From: beigel-richard@CS.YALE.EDU (Richard Beigel)
Newsgroups: comp.theory
Subject: rational zeroes of multivariate polynomials
Date: 28 Aug 92 18:03:00 GMT
Reply-To: Richard Beigel <beigel-richard@CS.YALE.EDU>

Matijasevic proved that there is no algorithm to find integer zeroes
of multivariate polynomials.  In fact, this problem is m-equivalent to
the halting problem.  What about finding rational zeroes?  Is that
problem decidable?  m-equivalent to the halting problem?

-- Richard

[ This problem is listed as an open problem in the article by Davis,
Matijasevic and J. Robinson, in their paper on Hilbert's 10th problem
in the Hilbert Problem Symposium held in 1974.  Does anyone know of
any further results on this?: Editor ]
Newsgroups: comp.theory
From: rn@cs.brown.edu (Robert H.B. Netzer)
Subject: string matching: need pointers
Followup-To: rn@cs.brown.edu
Keywords: string matching
Organization: Brown University Department of Computer Science
Distribution: usa
Date: Tue, 25 Aug 1992 19:34:16 GMT

Given two sets of strings (that are large binary files), I am interested in
computing the set of longest identical sequences the two strings have in
common.  Different sequences in the set may or may not overlap; both cases
are of interest.  I'm interested in references to work on algorithms and
the complexity of this and related matching problems.
Newsgroups: comp.theory
From: aistmain@vntic.msk.su (Dispatcher of AIST-EuroAIST-RELCOM Boris I. Tarakanov)
Subject: NEW CIPHER-SYSTEM
Summary: NEW CIPHER-SYSTEM
Keywords: NEW CIPHER-SYSTEM
Reply-To: aistmain@vntic.msk.su
Organization: AIST-VNTIC INFORMATION NETWORK
Date: Mon, 31 Aug 92 01:20:14 +0300

              New cipher-system

 1. When the original information is euciphered every bit is
    treaded and redundancy of this information is absent
 2. The amount of variants of eucipher may be so much great,
    for example n=10**91
 3. The quantity of encipher operations for 1 bit are <=22,
    but decipher operations are <= 9 for case n=10**91
 4. Ecodered file is deciphered in turn bit from the end  of
    the text.

    This new cipher-system may be  used  for  protection  of
    information  from   unauthorized  access  and  for  data
    communications by communication chanels.

    Relation by electronic mail.



Newsgroups: comp.theory
From: is@IME.USP.BR (Imre Simon)
Newsgroups: comp.theory
Subject: Are there reductions from Hilbert's 10th problem?
Date: 1 Sep 92 01:02:05 GMT
Reply-To: Imre Simon <is@ime.usp.br>

Reading a recent posting by Richard Beigel about Matijasevic, Hilbert, etc
reminded me that quite recently I saw a very ingenious proof of the
undecidability of a problem in the Theory of Finite Automata by Daniel Krob,
<dk@litp.ibp.fr> in

      "The equality problem for rational series with multiplicities
       in the tropical semiring is undecidable".

At the end of this note I give some details about the problem.

Krob's proof is achieved by a reduction from Hilbert's 10th problem,
i.e. that of finding integer zeroes of multivariate polynomials with integer
coefficients, whose undecidability has been proved by Matiasevic about 20
years ago in what was considered as a major advance in the area. The use of
Hilbert's 10th instead of some other more conventional undecidable problem,
like the Post Correspondence Problem, seems very much necessary at this moment.

My question is this: does anyone know of other undecidable problems, in
Theoretical Computer Science, apparently unrelated to multivariate
polynomials, whose undecidability is established by a reduction from Hilbert's
10th problem?

I will be glad to post an abstract of the answers  I receive.

Imre Simon <is@ime.usp.br>

* * * * *

About the problem solved by Krob:

The problem is related to computations in the tropical semiring (consisting of
the natural numbers extended with infinity and whose operations are minimum
and addition; note that this is the usual semiring to compute shortest paths
and that one does not have multiplication readily available in this
structure).  I would be glad to give a precise statement of the problem for
anyone who requests it.

The (previous) openness of this equivalence problem was reasonably well known
in the area and as far I know an overwhelming majority thought that the
problem would turn out to be decidable.

Krob's solution also implies the undecidability of another problem whose
undecidability has been established by Oscar Ibarra, using a very elaborate
reduction from the halting problem, and independently by L.P. Lisovik who used
a reduction from the Post Correspondence Problem.

* * * * *

Other references:

O. Ibarra
The unsolvability of the equivalence problem for \epsilon-free NGSM's with
unary input (output) alphabet and applications.
SIAM J. Comput., 7 (1978), 524-532

I. Simon
Recognizable sets with multiplicities in the tropical semiring.
in MFCS'88, Lect. Notes in Comp. Sci. 324, Springer, 1988, 107-120.

L.P. Lisovik
The identity problem for regular events over the direct product of free and
cyclic semigroups (in Ukranian).
Dok. Akad. Nauk Ukraiinskoj RSR ser. A 6 (1979), 410-413.
English translation by Andreas Weber <weber@psc.informatik.uni-frankfurt.de>
From: freeman@gradient.cis.upenn.edu (Jon Freeman)
Newsgroups: comp.theory
Subject: Two questions about CSP's
Date: 4 Sep 92 03:04:41 GMT
Organization: University of Pennsylvania

Greetings.

1.  I would like to obtain a list of references that discuss the time
and space complexity of converting the variables in a constraint
satisfaction problem (CSP) from non-binary to binary form (i.e.,
converting a CSP to a SAT problem).

2.  I would also like some pointers to quotes from the literature in
which researchers express their opinion as to which of these
representations, if any, is better for a particular CSP technique or
set of techniques.  For example, in their paper "Backtracking with
Multi-Level Dynamic Search Rearrangement" (Acta Informatica 15:99-113,
1981), Purdom, Brown, and Robertson state:

	"Transforming a problem into one with binary variables
	 gives maximum scope to search rearrangement."

			Thanks in advance,
			       Jon
-------------------------------------------------------------------------------
"If the accelerator (gas pedal) sticks, the   | Jon Freeman
car will often keep going faster and faster." | freeman@gradient.cis.upenn.edu
   --Pennsylvania Driver's Manual, p. 55      | Office: (215) 898-4612
Newsgroups: comp.theory
From: mittle@watson.ibm.com (Josh Mittleman)
Subject: Re: Closest center
Date: Thu, 03 Sep 1992 17:33:51 GMT
Disclaimer: This posting represents the poster's views, not necessarily those of IBM
Organization: IBM T.J. Watson Research Center

Without bothering to stop and think, I wrote:

> I would appreciate any references on the following problem:
> 
> Given k sites, and n query vertices.  For each query vertex, report the
> nearest site.

After a few minutes thought, I realize that what I wanted was a 3D Voronoi
diagram.  Can someone therefore direct me to a reference on that subject?
Thanks & apologies for my laziness.

===========================================================================
Josh Mittleman (mittle@watson.ibm.com)
J2-C28 T.J. Watson Research Center, PO Box 704, Yorktown Heights, NY  10598
From: scot@moosilauke.dartmouth.edu (Scot Drysdale)
Newsgroups: comp.theory
Subject: A sorting Exercise
Date: 25 Aug 92 18:47:08 GMT
Organization: Dartmouth College, Hanover, NH
Originator: scot@moosilauke

The question about sorting a sequence on a closed loop with every crossing
labeled is called Jordan Sorting (from the Jordan Curve theorem, I assume).
It can be done in linear time.  See

K. Hoffman, K. Mehlhorn, P. Rosenstiehl, and R. E. Tarjan, "Sorting
Jordan Sequences in Linear Time," Proc. Symp. Computational Geometry,
pp. 196-203 (1985).

It was to appear in Information and Control in 1986, but I don't have a
reference.

-- 

Scot Drysdale
Dartmouth College
scot.drysdale@dartmouth.edu