We demonstrate Dagster, a system that implements new approach to scheduling interdependent (Boolean) SAT search activities in high-performance computing (HPC) environments. Our takes as input set of disjunctive clauses (i.e., DIMACS CNF) and labelled directed acyclic graph (DAG) structure describing how the are decomposed into interrelated problems. Component problems solved using standard syst...

In the context of Answer Set Programming, this paper investigates symmetry-breaking to eliminate symmetric parts of the search space and, thereby, simplify the solution process. We propose a reduction of disjunctive logic programs to a coloured digraph such that permutational symmetries can be constructed from graph automorphisms. Symmetries are then broken by introducing symmetry-breaking cons...

Markov networks and Bayesian networks are effective graphic representations of the dependencies embedded in probabilistic models. It is well known that independencies captured by Markov networks (called graph-isomorphs) have a finite axiomatic characterization. This paper, however, shows that independencies captured by Bayesian networks (called causal models) have no axiomatization by using eve...

It has recently been observed by Zuiddam that finite graphs form a preordered commutative semiring under the graph homomorphism preorder together with join and disjunctive product as addition multiplication, respectively. This led to new characterization of Shannon capacity $\Theta$ via Strassen's Positivstellensatz: $\Theta(\bar{G}) = \inf_f f(G)$, where $f : \mathsf{Graph} \to \mathbb{R}_+$ r...

ABSTRACT Estimation of mineral resources and reserves with low values of error is essential in mineral exploration. The aim of this study is to estimate and model a vein type deposit using disjunctive kriging method. Disjunctive Kriging (DK) as an appropriate nonlinear estimation method has been used for estimation of Cu values. For estimation of Cu values and modelling of the distributio...

In this work we tackle the Maximum Acyclic Subgraph problem under Negative Disjunctive Constraints (MASNDC) and the Maximum Acyclic Subgraph problem under Positive Disjunctive Constraints (MASPDC), both belonging to the NP Hard class. Disjunctive constraints can be negative, in which a certain pair of entities cannot be contained simultaneously in a feasible solution; or positive in that, given...

This is a summary of the PhD thesis defended by the author in September 2011 at thé Ecole des Mines de Nantes (EMNantes). The thesis was advised by Narendra Jussien (EMNantes) and co-advised by Louis-Martin Rousseau (´ Ecole Polytechnique de Montréal – Poly), Christelle Guéret (EMNantes) and André Langevin (Poly). The manuscript is written in French and can be obtained from The focus of the dis...

The Disjunctive Fuzzy Temporal Constraint Network (DFTCN) model is a framework that allows reasoning with fuzzy qualitative and quantitative complex temporal constraints. However, its general complexity is exponential. In this work, we review methods that can reduce this complexity, based on graph topology and preprocessing. The final goal is to integrate all these methods into a general tool f...

A fast branch & bound method for the open-shop problem based on a disjunctive graph formulation of the problem is developed. Computational results show that the method yields excellent results. Some benchmark problems from the literature were solved to optimality for the first time.