Perfect Difference Sets (I just learned) are a math thing; a set of K+1
numbers (K turns out to be an interesting parameter) from the N-1 nonzero
residues 1, 2, 3, ..., N-1 of integers modulo N, so that that every residue
is the difference of some pair of numbers in the PD set. If N = K^2 + K + 1
and K is a power of two it works out, e.g. K = 2, N = 7 (a prime, so the
residues form a finite field, also) e.g. {1, 2, 4} is a PDS mod 7, e.g. 2-4
= -2 = 5 (mod 7). So all of the 6 nonzero residues can be produced by
differences of those 3 in the PDS.
But how this is used as a coding for a network topology I have no idea. The
Wolfram site deines PDS as above but doesn't mention networks.
Peter
On 4/3/08, Douglas Eadline <[EMAIL PROTECTED]> wrote:
>
>
> From the EKA Wikipedia article:
>
> "The CRL supercomputer has been built using CLOS architecture"
>
> Maybe a link to:
>
> http://en.wikipedia.org/wiki/Clos_network
>
> would help the article. I am not sure what they mean
> by "perfect difference sets". Anyone know?
>
> --
> Doug
>
>
>
>
> > Slashdot mentioned a cluster topology based on "perfect difference sets"
> > used to build EKA, http://en.wikipedia.org/wiki/EKA_%28supercomputer%29
> > but
> > the wiki article doesn't mention it. The article
> >
> http://punetech.com/building-eka-the-worlds-fastest-privately-funded-supercomputer/only
> > mentions papers that require subscriptions.
> > Peter
> >
> > On 3/31/08, Rayson Ho <[EMAIL PROTECTED]> wrote:
> >>
> >> You can get detailed information on setting up a BSD HPC cluster at:
> >>
> >> http://people.freebsd.org/~brooks/papers/
> >>
> >> Grid Engine was ported and maintained by the author...
> >>
> >>
> >> Rayson
> >>
> >>
> >>
> >>
> >> On Sun, Mar 30, 2008 at 12:12 PM, Israel Lehnen Silva
> >> <[EMAIL PROTECTED]> wrote:
> >> > Hello friends!
> >> >
> >> > I am Brazilian, and i am doing a Beowulf Cluster in OS FreeBSD for
> a
> >> > project of University where i study the networking Infrastructure of
> >> > the link between the nodes.
> >> > If someone has other material that can help me, send me for me to
> >> > increase my project!
> >> >
> >> > Counting on the cooperation and support of the brothers.
> >> > --
> >> >
> >> > Att. Israel Lehnen Silva
> >> > _______________________________________________
> >> > Beowulf mailing list, Beowulf@beowulf.org
> >> > To change your subscription (digest mode or unsubscribe) visit
> >> http://www.beowulf.org/mailman/listinfo/beowulf
> >> >
> >> _______________________________________________
> >> Beowulf mailing list, Beowulf@beowulf.org
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> >>
> >
> >
>
> > !DSPAM:47f4612e224331745845678!
>
> > _______________________________________________
> > Beowulf mailing list, Beowulf@beowulf.org
> > To change your subscription (digest mode or unsubscribe) visit
> > http://www.beowulf.org/mailman/listinfo/beowulf
> >
> >
>
> > !DSPAM:47f4612e224331745845678!
> >
>
>
>
> --
> Doug
>
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