The Borg Project: AnnouncementsThe Borg Projecturn:uuid:2021debd-a6b9-47f7-96d1-600f79df87b12011-07-29T00:00:00ZResults from the 2011 solver competitionsurn:uuid:3c5db5a7-dd4f-5013-aad7-a6a6c31863162011-07-29T00:00:00Z
<p>
Borg has again placed first in the main category of the <a
href="http://www.cril.univ-artois.fr/PB11/">annual pseudo-Boolean solver
competition</a>, as it did in 2010. The <a
href="/pages/research/borg/files/borg_pb11.pdf">borg-pb-11 description</a> credits
the subsolvers essential to the performance of its portfolio approach.
Improvements this year include a more accurate model for reasoning about solver
performance, a more effective method for scheduling their execution, and the
integration of static instance features. Borg also solved the greatest number
of instances in the "random" category of the most recent SAT competition, but a
bug in certificate handling left it ineligible for a medal.
</p>
<p>
Our competition submissions <a href="/pages/research/borg/resources.html">are
available online</a>. If you are interested in testing or applying borg,
however, a more recent version is strongly recommended.
</p>
Visualizing solver performance dataurn:uuid:3b3a0d4d-2a24-57c3-81f7-f792456a8dab2011-06-19T00:00:00Z
<p>
The project has released an experimental web-based tool for visualizing solver
performance data, such as those collected by evaluations like the <a
href="http://satcompetition.org/">SAT competitions</a>. Visualizations of the
phase 2 results for the 2009 competition <a
href="http://www.cs.utexas.edu/~bsilvert/borgview/">are available now</a>, and
the 2011 results will be visualized soon after they are published. A modern
browser is required; <a href="http://www.google.com/chrome/">Google Chrome</a>
is strongly recommended.
</p>
Alpha Release of Data and Codeurn:uuid:b1741da1-2279-5044-90e8-368d38121d002010-08-23T00:00:00Z
<p>
The project has <a href="http://nn.cs.utexas.edu/pages/research/borg/resources.html">made available</a> an
initial "alpha" release of data sets and source code, in preparation for
distributing a more complete collection of data and documentation. These data
sets are intended to benefit the algorithm portfolio research community as a
whole: they allow other research groups to avoid the substantial cost of
gathering solver behavior data, and they provide a standard environment for
portfolio experiments. They represent hundreds of thousands of hours of
processor time.
</p>
Pseudo-Boolean competition victoryurn:uuid:63332e51-e6ba-53d2-b8f6-f21f2980c8852010-07-22T00:00:00Z
<p>
The results of the
<a href="http://www.cril.univ-artois.fr/PB10/">Fifth Annual Competition of Pseudo-Boolean Solvers</a>
were
announced at the
<a href="http://ie.technion.ac.il/SAT10/">
Thirteenth International Conference on Theory and Applications of Satisfiability Testing</a>
in Edinburgh, Scotland, and the PB variant of borg won the core
decision/linear-constraint categories. The margin between borg-pb and the
second-place solvers (SCIPspx, SAT4J RES CP, and SAT4J RES) was significant, in
some cases exceeding the gap between second and eighth.
</p>
<p>
As always, the portfolio's success would not be possible without the efforts of
individual solver authors (borg-pb, for example, includes SAT4J as one of its
subsolvers) and the open nature of the satisfiability research community. The
borg-pb <a href="http://www.cril.univ-artois.fr/PB10/solver/borg_pb10.pdf">solver
description</a> credits the subsolvers it used.
</p>
Publication at AAAI-10urn:uuid:22a77f89-2552-5a29-92b7-28178a305f302010-07-18T00:00:00Z
<p>
The <a href="http://nn.cs.utexas.edu/?silverthorn:aaai2010">paper</a> "Latent
Class Models for Algorithm Portfolio Methods", which develops the core solver
behavior model applied in borg, was presented at the
<a href="http://www.aaai.org/Conferences/AAAI/aaai10.php">
Twenty-Fourth AAAI Conference on Artificial Intelligence (AAAI-10)
</a>
in Atlanta, Georgia this past week. The conference featured plenty of
excitement around portfolio methods; some interesting and related papers from
other research groups are highlighted in
<a href="http://www.twitter.com/borg_project">our updates feed</a>.
</p>