HDTenEightyP/NetNews huggingface dataset:
From: andrew@lsa.ncl.omron.co.jp (Andrew Walduck)
Newsgroups: comp.specification
Subject: Re: formal methods in US
Date: 14 Apr 92 05:09:36 GMT
Reply-To: andrew@lsa.ncl.omron.co.jp (Andrew Walduck)
Distribution: comp.specification

In article <4521577@harvee.UUCP>, esj@harvee.UUCP (Eric S Johansson) writes:
|> In article <1992Mar31.164952.18327@beaver.cs.washington.edu>
jon@cs.washington.edu
|> (Jon Jacky) writes:
|> 
|> > In article <1992Mar31.015456.2392@oracorp.com> narayana@oracorp.com
(K. T. Narayana) writes:
|> > > I would appreciate if people cut off this half baked survey of people
|> > > working in formal methods in north america. 
|> > > ...kt
|> > 
|> > In contrast, I would like to say that I have found this interesting
and do 
|> > appreciate seeing it, and would welcome additional contributions.  
It's easy
|> > enough for people to skip over articles that do not interest them.
|> 
|> 
|> I too have found this communication interesting and I have been
|> entertaining thoughts of it degenerating into a comp.specification.aa
|> meeting (my name is eric and I am a coder :-) 
|> 
|> This discussion is dealing (indirectly) with change.  How do I get {
|> myself, my manager, my coworkers, ... } to change to understand and 
|> hopefully use formal methods.  by understanding what we learn, how we
|> learn it and what motavates us to learn formal methods, we can convince
|> others and know what to teach them.  In trying to change my work environment
|> I have encountered indifference, hostility, fear and far too little
|> excitement.  

How do you get people to use assert()  {a form of
pre-conditions/post-conditions}
How do you get people to design instead of hack??
How do you get people to "throw the first 2 away"??
How do you explain to people that code is "written once" ... "maintained
forever"
How do you explain to people that finding bugs is a "good thing"... as it
    means you won't ship them to the customer...
How do you get people to re-use?? Not re-invent??

Nobody likes to be told how to do their job. Or that they could do it better...
or that there is a better way...

This is more of a social problem...a resistance to new ideas...

(the solution to which has been left as an excercise for the student!! ;-)

Andrew Walduck -- OMRON Japan -- andrew@lsa.ncl.omron.co.jp 
-------------------------------------------------------------------------------
Henry Spencer says "Retch barf." 
-------------------------------------------------------------------------------
From: trdgav01@uctvax.uct.ac.za (Gavan Tredoux)
Newsgroups: comp.specification
Subject: Re: formal methods in US
Date: 11 Apr 92 08:05:21 +0200
Distribution: comp.specification
Organization: FACCS LAB, UCT

In article <1992Mar29.180106.3876@gmuvax2.gmu.edu>, agoodloe@gmuvax2.gmu.edu (Alwyn Goodloe) writes:
>    You are certinally correct that there isn't much interest in formal
> methods in the US, especially in comparrison to europe of the UK.
> Let me see if I can give you a survey of what I know is being done
> in US universities, research labs, and industry.

Why don't we broaden this discussion into a survey of formal methods around the
world? I can report that I am researching an MSc thesis in a formal-methods
area, in South Africa, at the University of Cape Town. If by `Formal Methods'
you include semantics, then we have a group of two research leaders and 7 grad
students working in this area. We are the only such group in the country,
however.  
-- 
+----------------------------------------------------------------------------+
| Gavan Tredoux, Dept. Math. |  "Einstein and people like Einstein said that |
| University of Cape Town    |   the world was flat" T(uesday) Lobsang Rampa |
| Rondebosch 7700 RSA        |                                               |
+----------------------------------------------------------------------------+
Newsgroups: comp.specification
From: john@citr.uq.oz.au (John Gottschalk)
Subject: specification languages in OSI
Keywords: Estelle, LOTOS, OSI
Organization: Prentice Centre, University of Queensland
Date: Wed, 15 Apr 1992 06:47:25 GMT


Hello all,

I would like to know of other people's thoughts in using Estelle, LOTOS or Z
in the specification and implementation of OSI application layer services. 
The idea is to use these languages is not just in the specification of the 
services and protocols, but also in the implementation by the use of a
compiler to C or C++ (for example). The discussion should not be mainly 
concerned with the availability of a good compiler, but with the 
suitability of these languages in the implementation of the layer 7 services. 

Regarding the Estelle option, the software design should consider 
whether a mixed implementation should be used (i.e. there would  
be external data types and functions defined in another language), or would
Estelle be used completely as an implementation language. A mixed
implementation could use the strengths of Estelle to specify and implement
the components that it is especially good at, while using another language
for other operations. This appraoch may apply to other specification languages
as well (is this possible?).

Some specific questions which could be answered are:

	* Is a mixed implementation the best approach, or should the
	implementation be based entirely on the specification language.

	* If a mixed implementation is a good idea then what parts should the
	specification language be used for? How much of the software
	would this be approximately (e.g. 10%, 50%, 90%)?

	* How suitable are the languages for the implementation of
	OSI application layer services? For example, the implementation must 
	consider the protocol specification (a finite state machine)
	and the service specification. How useful are Estelle, etc., for
	these parts. Note that experiences in the lower layers may not
	necessarily apply directly to the application layer where there
	is perhaps a relatively smaller protocol specification, and a 
	greater service aspect.

	* Would anybody seriuosly consider implementing an application
	layer service using one of these specification languages?

	* Has anybody implemented an application
	layer service using one of these languages?

Please present other ideas if they are relevant. Also, refer to journal 
articles or other documents if they are useful in the discussion.


If there is plenty of interest then I will summarise the responses.


			-- thanks for your time, John Gottschalk

===================================================================== 
     John Gottschalk (john@citr.uq.oz) 
     Centre for Information Technology Research,
     The University of Queensland, 4072, 
     Brisbane, Queensland, Australia,
     +61 7 365 4321 (phone), +61 7 365 4399 (fax)
=====================================================================
From: fpst@hubcap.clemson.edu (Steve Stevenson-Moderator)
Newsgroups: comp.parallel
Subject: No news for the remainder of the week...
Date: 7 Apr 92 11:43:16 GMT
Organization: Clemson University

I'll be out of town the rest of the week doing professorial sorts of
nonsense. If I get a chance, I'll try to post on Thursday.

Steve

=========================== MODERATOR ==============================
Steve Stevenson                            fpst@hubcap.clemson.edu
Administrative address                     steve@hubcap.clemson.edu
Department of Computer Science,            comp.parallel
Clemson University, Clemson, SC 29634-1906 (803)656-5880.mabell
Newsgroups: comp.parallel
From: "Wailer at the Gates of Dawn" <banshee@cats.UCSC.EDU>
Subject: Re: parallel fast multipole method
Keywords: multipole, molecular dynamics
Source-Info:  From (or Sender) name not authenticated.
Organization: University of California, Santa Cruz
Date: 5 Apr 92 14:07:20 GMT



	Check:

	Parallel Version of the FMM
	Computers Math Applications
	20,7 63 (1990)

	Implementing the FMM in 3D
	KE Schmidt  MA Lee
	J Stat Phys
	63, 1223 (1991 June)

	Fast Algorithm for Particle Simulations
	Greengard  Rokhlin
	J Comp Phys
	73, 325  (1987)

	I've seen very little actual use of the FMM, most of the above is 
benchmarking and algorithm proofs.  There are some MIT and Yale tech reports
that I've not been able to get copies of as yet.  Please post or mail if there
are some application-based papers on the FMM that I've missed.

-- 
The Wailer at the Gates of Dawn              | banshee@cats.UCSC.EDU       |
Just who ARE you calling a FROOFROO Head?    |                             |
DoD#0667  "Just a friend of the beast."      | banshee@ucscb.UCSC.EDU      |
2,3,5,7,13,17,19,31,61,89,107,127,521,607....| banshee@ucscb.BITNET        |
From: jet@karazm.math.uh.edu (J Eric Townsend)
Newsgroups: comp.parallel
Subject: Re: Raytracing on a CM
Date: 16 Apr 92 07:04:23 GMT
Organization: UH Dept of Math




alan@msc.edu (I think that's it) once gave me some source he'd written
for a primitive raytracer on the CM.  (As I'm working on a MIMD tracer
aimed at making movies of molecules, I decided to find *anything*
having to do with parallel ray tracing.)

Unfortunately, I don't have a CM handy to test it on.  However, if you
ask Alan politely, he'll probably give you a copy more recent than the
one I have.

Somebody wrote:
>Not necessarily.  Careful reorganization of the algorithms may let you
>take advantage of the CM-2.  Of course, this is just off the top of my
>head and not a statement based on a careful analysis of how well this
>problem maps to the CM architecture.

You might want to look at some of the work done with vectorizing ray
tracers.  It's a similar problem in that ray tracing isn't that
vectorizable, so things have to be seriously reorganized to get
anything done in a reasonable amount of time.

A bit of groundless speculation:  what about dumping ray tracing
except for final image generation, and doing the "real" work via
radiosity (which makes really nice pictures :-).  If you want, you
could do radiositize->ray trace specular->reradiositize->ray trace
final image or some such.  Go back and forth between a CM and a MIMD
machine.

(On a related front -- I heard a rumor that CM-5's aren't shipping
with vector or high-end floating point support.  Is this true?  Are
they really scalar + sparc floating only?)



--
J. Eric Townsend - jet@uh.edu - Systems Wrangler, UH Dept of Mathematics
Note! New vox number: (713) 743-3466  '91 CB750, DoD# 0378
     Want to report illegal or corrupt activities by a federal agency?
        Call the Federally-sponsored Whistleblower BBS: 202.225.5527
From: primeaux@duncan.cs.utk.edu (David Primeaux)
Newsgroups: comp.parallel
Subject: concurrent file system on the iPSC RX
Date: 3 Apr 92 20:55:39 GMT
Article-I.D.: utkcs2.ktphibINN8he
Reply-To: primeaux@duncan.cs.utk.edu (David Primeaux)
Organization: Computer Science Dept, University of Tennesee, Knoxville

I have some questions about the concurrent file system on
the iPSC RX.  

What would happen if two nodes tried to read and/or write
to a cfs file simultaneously?

I would hope cfs performance is faster than file access through
the host node.  What is the (ball park) difference in performance?
Does the presence of other cfs users affect performance?

How much slower is cfs file access when compared to:
        a)  local memory access
        b)  inter-node communication

Does the size of the memory on the cfs vary from one system
to another?  If so, what are the ranges?


If you have answers about any of these questions, I would certainly
like to hear from you.  

Thanks!

-- David Primeaux
From: tardif@outaouais.ulaval.ca (Pierre-Martin Tardif)
Newsgroups: comp.parallel
Subject: Portable compiler
Keywords: compiler, parallel
Date: 15 Apr 92 19:36:29 GMT
Organization: Universite Laval
Apparently-To: uunet!comp-parallel

I just like to know where and how people are doing research about
a portable compiler for the parallel computers (independant of
the architecture) ?
-- 
Pierre-Martin Tardif, etudiant gradue  (email: tardif@gel.ulaval.ca)
Laboratoire de Vision et Systemes Numeriques
Universite Laval, Pavillon Adrien-Pouliot, local 00100-I, Ste-Foy, Quebec,
Canada, G1K 7P4         (418-656-2131, ext 4848)
Newsgroups: comp.parallel
From: ncs@cs.rit.edu (Nan C Schaller)
Subject: Occam and Transputer Engineering Course Update
Organization: Rochester Institute of Technology, Rochester, NY
Distribution: na
Date: 10 Apr 92 12:45:01 GMT


		   **** COURSE UPDATE ****

              OCCAM AND TRANSPUTER ENGINEERING
   An Intensive Short Course for Scientists and Engineers

                     May 27 - 29, 1992

             Rochester Institute of Technology
                    Rochester, New York


Rochester Institute of Technology is happy to announce the arrival
of the PACT parallel C compiler.  We are working to incorporate the
use of this parallel C compiler into the hands-on portion of 
our May "OCCAM AND TRANSPUTER ENGINEERING COURSE".  Our current 
intention is to include C examples as exercises on the last day
of the course.

In addition, CSA has promised delivery of one of their Education Kits
for your examination during the course.  This kit contains a single 
transputer board and a startup version of the INMOS toolset for use 
in an IBM PC.  We will be giving this kit away via a drawing at the 
end of the course.  

Literature and demonstations from other vendors will also be available.

The deadline for course registration is April 15.  If you need furthur
information concerning the course or if I can answer any further 
questions, please feel free to call me or send me e-mail.

			Nan Schaller
			Rochester Institute of Technology
			ncs@cs.rit.edu
			(716) 475-2139

Newsgroups: comp.parallel
From: bourne-linda@CS.YALE.EDU (Linda Bourne)
Subject: Alan J. Perlis Symposium
Apparently-To: comp-parallel@uunet.uu.net
Organization: Yale CS Mail/News Gateway
Date: Wed, 8 Apr 1992 20:08:23 GMT

ALAN J. PERLIS SYMPOSIUM:  Parallel Computers of the Future

Sponsored by the Department of Computer Science, Yale University

April 23, 1992

Sheffield-Sterling-Strathcona Hall
Room 114
Corner Grove and Prospect Streets
New Haven, Connecticut


Morning Session (9:30-11:00)

	Opening Remarks
		Drew McDermott
		Chairman, Yale CS

	"Dataflow Architectures:  From Monsoon to *T"
		Arvind
		Massachusetts Institute of Technology


Afternoon Session (1:30-4:30)

	"PRAMs:  Theory, Physical Design, and Application"
		Wolfgang Paul
		University of Saarbrucken

	"Will Parallel Architectures Converge?"
		H.T. Kung
		Carnegie-Mellon University



Following the last talk a public reception will be held at the
Department of Computer Science, Arthur K. Watson Hall.

All talks are free and open to the public.

For further information please call (203) 432-1246.
-------


Newsgroups: comp.parallel
From: aboba@world.std.com (Bernard D Aboba)
Subject: User Survey
Apparently-To: uunet!comp-parallel
Summary: Student survey on uses of parallel machines
Keywords: survey parallel 
Organization: The World Public Access UNIX, Brookline, MA
Date: Thu, 16 Apr 1992 20:05:30 GMT

We are currently working on a project on the future of
various parallel architectures, at the Berkeley School
of Business. 
 
We are interested in people's experience with various
hardware and software vendors. Specifically, we are
interested in:
 
1. What problems you are working on.
2. What hardware and software features are most important to you.
3. Your experience with support at various vendors.
4. Your predictions as to the penetration of this technology in your
   field of interest. 
5. Name the top 5 vendors you would consider in purchasing hardware
and why.    
 
I will summarize the results for the net. Thank you for your help!
 


Newsgroups: comp.parallel
From: mrm@puffin.Eng.Sun.COM (Marianne Mueller)
Subject: Re: parallel fast multipole method
Keywords: multipole, molecular dynamics
Organization: Sun Microsystems, Mt. View, Ca.
Date: 8 Apr 1992 23:02:01 GMT

A polymer physicist at DuPont, Dr Lustig, has good results using fast
multipole method in conjunction with SIMD implementation on
hypercubes.  Using fast multipole & SIMD, his applications now run
faster on the hypercube than on Cray Y/MP.  He's interested in
molecular dynamics of dense substances.

Dr Lustig is part of the Rutgers CAIP project (Computer Aids for
Industrial Productivity.)  I think he's publishing his results but I
don't know when or where!  Try contacting him through CAIP:

Center For Computer Aids for Industrial Productivity
Rutgers University
Frelinghuysen Road
P.O. Box 1390
Piscataway, NJ 08855-1390

Tel: (908) 932-4208
From: alan@msc.edu (Alan Klietz)
Newsgroups: comp.parallel
Subject: Re: Raytracing on a CM
Date: 15 Apr 92 21:03:29 GMT
Organization: Clemson University

>>	Argh! The CM-2 is a SIMD machine. It implies that all processors must
>>do the same thing at the same time. As the ray trees will be quite different
>>from one pixel to another, (not even speaking of texture and shadow rays
>>computation), you will be in BIG trouble.
>
>Not necessarily.  Careful reorganization of the algorithms may let you
>take advantage of the CM-2.  Of course, this is just off the top of my
>head and not a statement based on a careful analysis of how well this
>problem maps to the CM architecture.

Actually it's pretty straightforward.  You assign a ray to each
virtual processor and then let them bounce around in the scene indepen-
dently.  The trick is minimizing the number of object/ray intersection 
tests. 

If you have a small number of objects (say 100 or less) the best
way is to broadcast the database.  This actually works quite well
since there is no interprocessor communication ("embarrassingly parallel")
and the CM is good at broadcasting information quickly.  You can 
raytrace a movie in near realtime this way.

If you have a large number of objects, you end up doing gathers
with each ray fetching an object that is 'nearby'.  The criteria
of 'nearness' is chosen with your favorite ray tree subdivision 
algorithm.  I used Goldmon & Salmon automatic boundary hierarchies with
convex quadrics for the boundaries (e.g. spheres for the sphereflake). 
Karl Sims and Hugh Delany have published work on SIMD octrees.  Other
subdivision algorithms would work as well.  The bottleneck is that
you ultimately end up doing a random GET (gather) operation for the rays
to fetch from the database, which tends to run slowly on the CM-2 for
large number of sources and destinations.

As an alternative, you could try an orthographic projection or 
spatial embedding and maybe use the NEWS grid, or you can punt and use
a machine with a fast random network like the CM-5.

--
Alan E. Klietz
Minnesota Supercomputer Center, Inc.
1200 Washington Avenue South
Minneapolis, MN  55415
Ph: +1 612 626 1737	       Internet: alan@msc.edu
From: payne@odin.unomaha.edu (Matt G. Payne)
Newsgroups: comp.parallel
Subject: Communication on the Connection Machine
Summary: Looking for details on communcation costs
Keywords: Communication, cost, help
Date: 15 Apr 92 17:54:49 GMT
Organization: University of Nebraska at Omaha

Greetings!

I'm a bit confused about the costs of communication on the CM2 and how
it relates to the communication mechanisms available in C*.  Your
help in clearing a few things up would be greatly appreciated.  

Supose there is a 2-dimensional shape:
	
	(0,0) (1,0)

	(0,1) (1,1)

By using one of the C* functions, it is very efficient & fast to send
from (0,0) to (1,0), since the communication is in just one dimension.
Left indexing may be used to send from (0,0) to (1,1), EG:
	[0][0]x = [1][1]y;
My questions are:
	1) Does this cost more than two efficient one-dimension
	   sends -- (0,0) to (1,0) to (1,1)?  
	2) If so, how much more?  
	3) Is there anyway to get C* to optimize your left indexing?  
	4) Is the cost of left-indexing communication proportional to
	   the distance between the VPs?  How much more does
	   "[0][0]x = [100][100]y" cost than "[0][0]x = [1][1]y"?
	   How does this communication-cost(distance) function work??
	5) How is contention handled?  If a C* fragment like:
		where (blah) 
		   {
		   [i][j]x=[k][l]y;
		   }
	   causes N VPs to send messages to one another, how is the
	   contention handled?  Is there a way to predict ahead of
	   time what the performance will be when doing N left-index
	   operations simultanously?

	   
Lastly, my group is experimenting with an implementation of the
Chandy-Misra simulation algorithm for circuit simulation on a CM2
in C* and I would appreciate any comments, thoughts, or communication
with anyone who has done (or heard about) anything related to this.

Thank you very much for your time. --- matt :-)


--
"The world would be a better place if people only communicated with e-mail."
-- payne@odin.unomaha.edu
From: tkm@eos.ncsu.edu (Dr. Tom Miller)
Newsgroups: comp.parallel
Subject: System memory overhead on parallel machines
Date: 6 Apr 92 22:44:48 GMT
Reply-To: tkm@eos.ncsu.edu (Dr. Tom Miller)
Organization: Project EOS - North Carolina State University
Apparently-To: comp-parallel@mcnc.org

I need to know the per-node memory overhead (the amount of memory consumed
by the run-time kernel and any other run-time system memory overhead)
for any or all of the following parallel machines:

Intel iWARP
Intel IPSC/860
Intel Paragon
nCUBE/2
Meiko Computing Surface (with i860 processors)

Please send replies to tkm@ncsu.edu.  Thanks,

Tom Miller
Newsgroups: comp.parallel
From: rbe@yrloc.ipsa.reuter.COM (Robert Bernecky)
Subject: Re: Fast window summation on a SIMD machine
Apparently-To: uunet!comp-parallel
Reply-To: rbe@yrloc.ipsa.reuter.COM (Robert Bernecky)
Organization: SNake Island Research Inc, Toronto
Date: 	Thu, 16 Apr 1992 12:11:55 -0400


In article <1992Apr14.180225.182521@cs.cmu.edu> br@cs.cmu.edu writes:
>
>    I am looking for an idea for a high-performance algorithm for
>    the following problem:
>
>	I have a large SIMD machine (maspar) with an image distributed
>	across the 2-dimensional array of processors.  Each processor has
>	a small (8*8), square piece of the image.  I want to produce a new
>	image in which the new pixels represent the sum, in the original
>	image, of a large (64*64) window around that pixel.  
>
>	Currently, I copy the large window of pixels onto each processor from
>	the surrounding processors and then perform an efficient window
>	summation algorithm without having to do any further communication.
>	This is very inefficient because each processor is duplicating many
>	of the additions of its neighbors.

It seems to me that a wavefront technique might do the job. In APL, 
we tend to solve these things by computing sum scan across the rows
(for example), then subtracting the Nth-shifted version of the scan
from the original sum scan. This is used for things such as moving-
averages, etc.   That works directly on lists. For tables (8*8, etc),
you need to get a bit fancier, but the idea is similar. 




Robert Bernecky      rbe@yrloc.ipsa.reuter.com  bernecky@itrchq.itrc.on.ca 
Snake Island Research Inc  (416) 368-6944   FAX: (416) 360-4694 
18 Fifth Street, Ward's Island
Toronto, Ontario M5J 2B9 
Canada
From: rminnich@super.super.org (Ronald G Minnich)
Newsgroups: comp.parallel
Subject: Re: Atomic read/writes to memory in SMMs
Date: 6 Apr 92 23:31:31 GMT
Organization: Supercomputing Research Center (Bowie, MD)
Apparently-To: uunet!comp-parallel

In article <1992Apr6.230404.4322@hubcap.clemson.edu> kweber@Snake.mcs.kent.edu (Ken Weber) writes:
>What I am referring to is the ability for a 32-bit value to be either written
>or read atomically from a memory location.  I could envision the situation
>where a read/write may work with only 16 bits of a value at a time.  This
>could lead to the following situation:

oh, i see now. Well, if anyone out there can think of a multiprocessor, 
BUILT AFTER 1980 (see, i get out of having to worry about C.mmp and CM*)
that was not a true 32-bitter, I would be interested in hearing about 
it. To further restrict things, I won't count (e.g.) 
8086 cards in a multibus rack, as lots of these were done for industrial 
control, but they hardly count as multiprocessors in the same sense as
a Sequent. 

But, for your case Ken, I think it safe to assume that 32-bit
writes are atomic. 

someone want to show me wrong?
ron
Newsgroups: comp.parallel