Reformulation of a problem is intended to make the problem more amenable to efficient solution. This is equally true in the special case of reformulating a planning problem. This paper considers various ways in which reformulation can be exploited in planning.

In this paper we survey recent work on the perspective reformulation approach that generates tight, tractable relaxations for convex mixed integer nonlinear programs (MINLP)s. This preprocessing technique is applicable to cases where the MINLP contains binary indicator variables that force continuous decision variables to take the value 0, or to belong to a convex set. We derive from first prin...

We claim in this paper that “context” is a key design concept for stimulating people’s mind to discover new interpretations and understandings in the digital archive. Our approach to the notion of context is unique in terms of the proposal of the model of context from the viewpoint of database systems and informatics. We assume that content is actually comprised by two basic elements, namely co...

We discuss the hierarchies of linear and semidefinite programs defined by Lovász and Schrijver [33]. We describe recent progress on these hierarchies in the contexts of algorithm design, computational complexity and proof complexity.

We are concerned with the compatible gauge reformulation for H(div) equations and the design of fast solvers of the resulting linear algebraic systems as in [5]. We propose an algebraic reformulation of the discrete H(div) equations along with an algebraic multigrid (AMG) technique for the reformulated problem. The reformulation uses discrete Hodge decompositions on co-chains to replace the dis...

This paper proposes an approximate query reformulation framework for integrating heterogeneous ontologies. In order to achieve semantic interoperability in the Semantic Web, multiple ontologies have to be integrated. Ontology integration requires approximation mechanisms, since often no perfectly corresponding ontologies exist. However, most previous research efforts on ontology integration hav...

Ontology-based data access is an approach to organizing access to a database augmented with a logical theory. In this approach query answering proceeds through a reformulation of a given query into a new one which can be answered without any use of theory. Thus the problem reduces to the standard database setting. However, the size of the query may increase substantially during the reformulatio...

Topos Quantum Theory (TQT) is standardly portrayed as a kind of ‘neo-realist’ reformulation of quantum mechanics. In this paper, we study the extent to which TQT can really be characterised as a realist formulation of the theory, and examine the question of whether the kind of realism that is provided by TQT satisfies the philosophical motivations that are usually associated with the search for...

This article deals with a study of the MPEC problem based on a reformulation to a DC problem (Difference of Convex functions). This reformulation is obtained by a partial penalization of the constraints. In this article we prove that a classical optimality condition for a DC program, if a constraint qualification is satisfied for MPEC, it is a necessary and sufficient condition for a feasible p...

A conditional constraint satisfaction problem (CCSP) extends a standard constraint satisfaction problem (CPS) with a conditionbased component that controls what variables participate in problem solutions. CCSPs adequately represent configuration and design problems in which selected subsets of variables, rather than the entire variable set, are relevant to final solutions. The only algorithm th...