3 research outputs found
An Analysis of the Effect of Community Structure on SAT Solver Performance
Despite enormous improvements in Boolean SATisfiability solver performance
over the last decade, it is still unclear why specific input formula are slow
to solve, when other similarly specified formula execute more quickly. This
work explores the relationship between the community structure of a SAT
formula and its execution time on several state-of-the-art solvers. We explore
the analysis of this data from a number of directions; first, we explore the
relationship between the well known clause-variable ratio result, and com-
munity structure in randomly generated instances. Second, we perform a
standard linear regression on data obtained from the 2013 SAT competition.
Third, we present a visualisation tool and data repository for viewing the
structure of a SAT formula. Fourth, we explore the effect of hardware con-
straints on the solution time of instances across various machines. Finally,
we explore survival analysis, a technique that is new to the field of Boolean
SATisfiability. By collating the results from each of these experiments, we
have determined that the community structure is critical in determining the
solution time of a SAT formula, more important than the clause-variable
ratio of the formula. While this work is not a complete explanation of the
varying solution time of SAT formulae, it has provided us with significant
insight for further research to answer the question: why different similarly
specified formula have such different solution times?4 month
DPvis - a tool to visualize the structure of SAT instances. SAT 2005 : international conference on theory and applications of satisfiability testing
Abstract. We present DPVIS, a Java tool to visualize the structure of SAT instances and runs of the DPLL (Davis-Putnam-Logemann-Loveland) procedure. DPVIS uses advanced graph layout algorithms to display the problem’s internal structure arising from its variable dependency (interaction) graph. DPVIS is also able to generate animations showing the dynamic change of a problem’s structure during a typical DPLL run. Besides implementing a simple variant of the DPLL algorithm on its own, DPVIS also features an interface to MiniSAT, a state-of-the-art DPLL implementation. Using this interface, runs of MiniSAT can be visualized—including the generated search tree and the effects of clause learning. DPVIS is supposed to help in teaching the DPLL algorithm and in gaining new insights in the structure (and hardness) of SAT instances.