Improving Diversification in Local Search for Propositional Satisfiability
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Author(s)
Primary Supervisor
Sattar, Abdul
Pham, Duc Nghia
Year published
2014
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In recent years, the Propositional Satisfiability (SAT) has become standard for encoding real world complex constrained problems. SAT has significant impacts on various research fields in Artificial Intelligence (AI) and Constraint Programming (CP). SAT algorithms have also been successfully used in solving many practical and industrial applications that include electronic design automation, default reasoning, diagnosis, planning, scheduling, image interpretation, circuit design, and hardware and software verification. The most common representation of a SAT formula is the Conjunctive Normal Form (CNF). A CNF formula is a ...
View more >In recent years, the Propositional Satisfiability (SAT) has become standard for encoding real world complex constrained problems. SAT has significant impacts on various research fields in Artificial Intelligence (AI) and Constraint Programming (CP). SAT algorithms have also been successfully used in solving many practical and industrial applications that include electronic design automation, default reasoning, diagnosis, planning, scheduling, image interpretation, circuit design, and hardware and software verification. The most common representation of a SAT formula is the Conjunctive Normal Form (CNF). A CNF formula is a conjunction of clauses where each clause is a disjunction of Boolean literals. A SAT formula is satisfiable if there is a truth assignment for each variable such that all clauses in the formula are satisfied. Solving a SAT problem is to determine a truth assignment that satisfies a CNF formula. SAT is the first problem proved to be NP-complete [20]. There are many algorithmic methodologies to solve SAT. The most obvious one is systematic search; however another popular and successful approach is stochastic local search (SLS). Systematic search is usually referred to as complete search or backtrack-style search. In contrast, SLS is a method to explore the search space by randomisation and perturbation operations. Although SLS is an incomplete search method, it is able to find the solutions effectively by using limited time and resources. Moreover, some SLS solvers can solve hard SAT problems in a few minutes while these problems could be beyond the capacity of systematic search solvers.
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View more >In recent years, the Propositional Satisfiability (SAT) has become standard for encoding real world complex constrained problems. SAT has significant impacts on various research fields in Artificial Intelligence (AI) and Constraint Programming (CP). SAT algorithms have also been successfully used in solving many practical and industrial applications that include electronic design automation, default reasoning, diagnosis, planning, scheduling, image interpretation, circuit design, and hardware and software verification. The most common representation of a SAT formula is the Conjunctive Normal Form (CNF). A CNF formula is a conjunction of clauses where each clause is a disjunction of Boolean literals. A SAT formula is satisfiable if there is a truth assignment for each variable such that all clauses in the formula are satisfied. Solving a SAT problem is to determine a truth assignment that satisfies a CNF formula. SAT is the first problem proved to be NP-complete [20]. There are many algorithmic methodologies to solve SAT. The most obvious one is systematic search; however another popular and successful approach is stochastic local search (SLS). Systematic search is usually referred to as complete search or backtrack-style search. In contrast, SLS is a method to explore the search space by randomisation and perturbation operations. Although SLS is an incomplete search method, it is able to find the solutions effectively by using limited time and resources. Moreover, some SLS solvers can solve hard SAT problems in a few minutes while these problems could be beyond the capacity of systematic search solvers.
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Thesis Type
Thesis (PhD Doctorate)
Degree Program
Doctor of Philosophy (PhD)
School
School of Information and Communication Technology
Copyright Statement
The author owns the copyright in this thesis, unless stated otherwise.
Item Access Status
Public
Subject
Propositional Satisfiability (SAT)
Artificial Intelligence (AI)
Constraint Programming (CP)
Complex constrained problems
Conjunctive Normal Form (CNF)