Network-based heuristics for constraint satisfaction problems

  title={Network-based heuristics for constraint satisfaction problems},
  author={Rina Dechter and Judea Pearl},
Many AI tasks can be formulated as Constraint-Satisfaction problems (CSP), i.e., the assignment of values to variables subject to a set of constraints. While some CSPs are hard, those that are easy can often be mapped into sparse networks of constraints which, in the extreme case, are trees. This paper identifies classes of problems that lend themselves to easy solutions, and develops algorithms that solve these problems optimally. The paper then presents a method of generating heuristic advice… 

Constraint Networks: A Survey

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The concept of CSP is defined and how some combinatorial problems can be modelled as CSPs are shown, and a detailed description of the basic techniques for constraint satisfaction is given.

Issues in the performance measurement of constraint-satisfaction techniques

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A parameter (τ) that measures the constrainedness of a search problem is introduced that represents the probability of the problem being feasible and can also be used in a heuristic to guide search.



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A subset of CSPs is identified whose syntactic and semantic properties make them easy to solve, and problems supported by tree-like constraint graphs, and some width-2 graphs are chosen as the target model for the relaxation scheme.

Consistency in Networks of Relations

A Sufficient Condition for Backtrack-Free Search

A relationship involving the structure of the constraints is described which characterizes to some degree the extreme case of mimmum backtracking and a concept called "width," which may provide some guidance in the representation of constraint satisfaction problems and the order in which they are searched.

A sufficient condition for backtrack-bounded search

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On the Discovery and Generation of Certain Heuristics

  • J. Pearl
  • Computer Science, Business
    AI Mag.
  • 1983
It is demonstrated that these heuristics can be obtained by the process of deleting constraints from the original problem and solving the relaxed problem which ensues, and a scheme for generating such heuristic mechanically is outlined.

Intelligent Backtracking in Plan-Based Deduction

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