Given a matrix of weights, the Linear Ordering Problem (LOP) consists of finding a permutation of the columns and rows in order to maximize the sum of the weights in the upper triangle. This NP-complete problem can also be formulated in terms of graphs, as finding an acyclic tournament with a maximal sum of arc weights in a complete weighted graph. In this paper we first review the previous met...

The present paper deals with the relationship between sense ordering and the primary function of the dictionary, arguing that the former should reflect the latter. I give suggestions as to how this could be achieved in practice, and which sense ordering would best serve the different functions. Given that lexicography appears to be at an important crossroads, I claim that lexicographers should ...

Classification is an important task in data mining processes. In this work, the χ test is used to define the order of the variables of a dataset to be used in Bayesian classification tasks. Two Bayesian classifiers are used to verify the influence of the variables ordering in the classification rate. The first one is based on the K2 algorithm which has strong dependency upon the initial order o...

A large variety of problems in digital system design, combinational optimization and verification can be formulated in terms of operations performed on Boolean functions. The time complexity of Binary Decision Diagram (BDD) representing a Boolean function is directly related to the path length of that BDD. In this paper we present a method to generate a BDD with minimum path length. The Average...

Adding symmetry breaking constraints is one of the oldest ways of breaking variable symmetries for CSPs. For instance, it is well known that all the symmetries for the pigeon hole problem can be removed by ordering the variables. We have generalized this result to all CSPs where the variables are subject to an all different constraint. In such case it is possible to remove all variable symmetri...

Heuristics for variable and value ordering have proven useful in searching for solutions to constraint satisfaction problem (CSPs). A well-known heuristic guides the search by ordering values based on an estimate of the number of solutions for the problem. In this paper, we introduce a new estimation method that approximates the probability that a given variable/value combination is part of a g...

A complete and accurate analysis of the complex spatial structure of heterogeneous hydrocarbon reservoirs requires detailed geological models, i.e. fine resolution models. Due to the high computational cost of simulating such models, single resolution up-scaling techniques are commonly used to reduce the volume of the simulated models at the expense of losing the precision. Several multi-scale ...