Search results for "Constraint satisfaction dual problem"
showing 2 items of 2 documents
Counting by Statistics on Search Trees: Application to Constraint Satisfaction Problems
1997
In 1975, Knuth proposed a simple statistical method for investigating search trees. We use this technique for estimating the number of solutions of constraint satisfaction problem CSP and boolean satisfiability problem SAT instances. We show that, depending on domain reductions, tree-based estimates have a lower variance than estimates based on uniform sampling from the search space. Nevertheless, because the variance remains extremely high in the general case, a confidence interval cannot be derived, but a lower bound of the number of solutions. These results are confirmed by many experiments.
Exact and Approximate Algorithms for Two–Criteria Topological Design Problem of WAN with Budget and Delay Constraints
2004
This paper studies the problem of designing wide area networks (WAN). In the paper the two-criteria topology assignment problem with two constraints is considered. The goal is select flow routes, channel capacities and network topology in order to minimize the total average delay per packet and the leasing cost of channels subject to the budget constraint and delay constraint. The problem is NP-complete. Then, the branch and bound method is used to construct the exact algorithm. Also the approximate algorithm is presented. Some computational results are reported. Based on computational experiments, several properties of the considered problem are formulated.