In the last few years, there has been a significant effort in designing and developing efficient Weighted MaxSAT solvers. We study in detail the WPM1 algorithm identifying some weaknesses and proposing solutions to mitigate them. Basically, WPM1 is based on iteratively calling a SAT solver and adding blocking variables and cardinality constraints to relax the unsatisfiable cores returned by the...

In this paper, we deal with a network design problem arising from the deployment of synchronous optical networks (SONET), a standard of transmission using optical fiber technology. The problem is to find an optimal clustering of traffic demands in the network such that the total number of node assignments (and, hence, add–drop multiplexer equipment requirements) is minimized, while satisfying t...

In this paper we consider the problem of "nding the e$cient frontier associated with the standard mean}variance portfolio optimisation model. We extend the standard model to include cardinality constraints that limit a portfolio to have a speci"ed number of assets, and to impose limits on the proportion of the portfolio held in a given asset (if any of the asset is held). We illustrate the di!e...

The SEt Reasoning Facility (SERF) integrates mechanisms for propagating membership propositions, deriving relations between sets, and reasoning about closure and cardinality into an efficient utility package for reasoning about sets. Assertions about relations between sets are compiled into a constraint network defined entirely in terms of union, complement, and emptiness constraints. The const...

Inexact pattern matching using semantic graphs has a wideranging use in AI systems, particularly in machine vision, case-based reasoning, and, recently, in intelligence analysis applications. While much previous work in the area has focused on matching simple flat graphs, there is increasing need for and use of complex graphical patterns with higher-order constructs—hierarchical graphs, cardina...

We introduce a new description logic that extends the wellknown logic ALCQ by allowing the statement of constraints on role successors that are more general than the qualified number restrictions of ALCQ. To formulate these constraints, we use the quantifier-free fragment of Boolean Algebra with Presburger Arithmetic (QFBAPA), in which one can express Boolean combinations of set constraints and...

Constraint Equations provide a concise declarative language for expressing semantic constraints that require consistency among several relations. The constraints provide a natural addition to semantic networks, as shown by an extension to the KL-ONE/NIKL representation language. The Equations have a more natural and perspicuous structure than the predicate calculus formulas into which they may ...

In case a CSP is over-constrained, it is natural to allow some constraints, called soft constraints, to be violated. We propose a generic method to soften global constraints that can be represented by a flow in a graph. Such constraints are softened by adding violation arcs to the graph and then computing a minimum-weight flow in the extended graph to measure the violation. We present efficient...

We study domain filtering algorithms for open constraints, i.e., constraints that are not a priori defined on specific sets of variables. We present an efficient filtering algorithm, achieving set-domain consistency, for open global cardinality constraints. We extend this result to conjunctions of them, in case they are defined on disjoint sets of variables. We also analyze the case when the se...