# Network-based heuristics for constraint satisfaction problems

@inproceedings{Dechter1988NetworkbasedHF, title={Network-based heuristics for constraint satisfaction problems}, author={Rina Dechter and Judea Pearl}, year={1988} }

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…

## 371 Citations

### Constraint Networks: A Survey

- Computer Science
- 2004

The techniques for solving the interval constraint satisfaction problem such as Waltz filtering and tolerance propagation are presented and a review of the intervals constraint satisfaction problems (ICSP) is presented.

### Distributing Constraints by Sampling in Non-Binary CSPs

- Computer Science
- 2003

This paper presents a distributed model for solving non-binary CSPs, in which agents are committed to sets of constraints, and a set of agents are incrementally and concurrently committed to building partial solutions until a problem solution is found.

### Why is Scheduling Difficult? A CSP Perspective

- BusinessECAI
- 1990

This paper explores how a sequence of successively more complex scheduling problems can be modeled as a CSP, and the relevance of existing CSP problem solving heuristics.

### Distributed Models for solving CSPs

- Computer Science
- 2007

This work presents two techniques for partition a CSP based on graph partitioning and based on trees, where the number of partition is unknown in advance.

### A quantitative solution to Constraint Satisfaction Problem (CSP)

- Computer ScienceNew Generation Computing
- 2009

In this quantitative approach, using variable transformation and constraint transformation, a CSP is transformed into a satisfiability (SAT) problem and the SAT problem is then solved within a continuous search space.

### A Graph Based Synthesis Algorithm for Solving CSPs

- Computer ScienceFLAIRS Conference
- 2003

This paper presents a solution synthesis algorithm called ω-CDGT which is an existing algorithm named CDGT augmented with a constraint representative graph calledπ-graph, and shows that the worst-case complexity of the ω -CDGT algorithm is better than other related algorithms.

### Solution Techniques for Constraint Satisfaction Problems

- Computer Science
- 2003

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

- Computer Science, BusinessArtif. Intell. Eng.
- 2000

### Learned Value-Ordering Heuristics for Constraint Satisfaction

- Business
- 2008

In global search for a solution to a constraint satisfaction problem, a value-ordering heuristic predicts which values are most likely to be part of a solution. When such a heuristic uses look-ahead,…

### Exploiting the Constrainedness in Constraint Satisfaction Problems

- Computer ScienceAIMSA
- 2004

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.

## References

SHOWING 1-10 OF 29 REFERENCES

### The Anatomy of Easy Problems: A Constraint-Satisfaction Formulation

- Computer ScienceIJCAI
- 1985

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.

### A Sufficient Condition for Backtrack-Free Search

- BusinessJACM
- 1982

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

- Computer ScienceJACM
- 1985

A relationship involving the structure of the constraints is described that provides a bound on the backtracking required to advance deeper into the backtrack tree, which leads to upper bounds on the effort required for solution of a class of constraint satisfaction problems.

### Increasing Tree Search Efficiency for Constraint Satisfaction Problems

- Computer ScienceArtif. Intell.
- 1980

### Consistent-Labeling Problems and Their Algorithms: Expected-Complexities and Theory-Based Heuristics

- Computer ScienceArtif. Intell.
- 1983

### On the Discovery and Generation of Certain Heuristics

- Computer Science, BusinessAI 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

- Computer ScienceIEEE Transactions on Pattern Analysis and Machine Intelligence
- 1985

It is proven that the algorithm is complete in the following sense: if for a given base a resolution refutation exists, then this refutation is found by the algorithm.

### Complexity of finding embeddings in a k -tree

- Mathematics, Computer Science
- 1987

This work determines the complexity status of two problems related to finding the smallest number k such that a given graph is a partial k-tree and presents an algorithm with polynomially bounded (but exponential in k) worst case time complexity.