Many constraint satisfaction and optimisation problems can be expressed using linear constraints on pseudo-Boolean (0/1) variables. Problems expressed in this form are usually solved by integer programming techniques, but good results have also been obtained using generalisations of SAT algorithms based on both backtracking and local search. A recent class of algorithm uses randomised backtrack...

We propose two new online methods for estimating the size of a backtracking search tree. The first method is based on a weighted sample of the branches visited by chronological backtracking. The second is a recursive method based on assuming that the unexplored part of the search tree will be similar to the part we have so far explored. We compare these methods against an old method due to Knut...

The problem of proving that a propositional boolean formula is satisfiable (SAT) is one of the fundamental problems in computer science. The application of SAT solvers in VLSI CAD has become of major interest. The most popular SAT algorithms are based on the well known Davis-Putnam procedure. There, to guide the search, a branching rule is applied for selecting and assigning unassigned variable...

This article presents an intelligent heuristic search algorithm (IHSA*) for solving flow-shop problems with two or three machines and an arbitrary number of jobs. Following its initial development the algorithm has been modified in two different ways in order to reduce backtracking and to improve its performance. The first modification concerns the choice of the best heuristic function to use, ...

In the last decades, helicopter-borne electromagnetic (HEM) method became a focus of interest in the fields of mineral exploration, geological mapping, groundwater resource investigation and environmental monitoring. As a standard approach, researchers use 1-D inversion of the acquired HEM data to recover the conductivity/resistivity-depth models. Since the relation between HEM data and model ...

In this paper, we consider the two-dimensional variable-sized bin packing problem (2DVSBPP) with guillotine constraint. 2DVSBPP is a well-known NP-hard optimization problem which has several real applications. A mixed bin packing algorithm (MixPacking) which combines a heuristic packing algorithm with the Best Fit algorithm is proposed to solve the single bin problem, and then a backtracking al...

Path finding algorithm addresses problem of finding shortest path from source to destination avoiding obstacles. There exist various search algorithms namely A*, Dijkstra's and ant colony optimization. Unlike most path finding algorithms which require destination co-ordinates to compute path, the proposed algorithm comprises of a new method which finds path using backtracking without requiring ...

We describe a method for transforming beam search into a complete search algorithm that is guaranteed to find an optimal solution. Called beam-stack search, the algorithm uses a new data structure, called a beam stack, that makes it possible to integrate systematic backtracking with beam search. The resulting search algorithm is an anytime algorithm that finds a good, sub-optimal solution quick...