We study the problem of encoding cardinality constraints (threshold functions) on Boolean variables into CNF. Specifically, we propose new encodings based on (perfect) hashing that are efficient in terms of the number of clauses, auxiliary variables, and propagation strength. We compare the properties of our encodings to known ones, and provide experimental results evaluating their practical ef...

This essay examines the use of famine-plot rhetoric in the course of disputes over free trade in the French Atlantic during the late eighteenth century. Seeking to discredit officially sanctioned trade monopolies, French plantation owners frequently suggested that the control exercised by metropolitan merchants over transatlantic commerce was responsible for food shortages among the enslaved po...

In this paper we consider the problem of creating a two dimensional spatial representation of gas distribution with a mobile robot. In contrast to previous approaches to the problem of gas distribution mapping (GDM) we do not assume that the robot has perfect knowledge about its position. Instead we develop a probabilistic framework for simultaneous localisation and occupancy and gas distributi...

The Strong Perfect Graph Conjecture, suggested by Claude Berge in 1960, had a major impact on the development of graph theory over the last forty years. It has led to the definitions and study of many new classes of graphs for which the Strong Perfect Graph Conjecture has been verified. Powerful concepts and methods have been developed to prove the Strong Perfect Graph Conjecture for these spec...

In this paper we give a characterization of kernel-perfect (and of critical kernel-imperfect) arc-local tournament digraphs. As a consequence, we prove that arc-local tournament digraphs satisfy a strenghtened form of the following interesting conjecture which constitutes a bridge between kernels and perfectness in digraphs, stated by C. Berge and P. Duchet in 1982: a graph G is perfect if and ...

In this article, we present a characterization of basic graphs in terms of forbidden induced subgraphs. This class of graphs was introduced by Conforti, Cornuéjols and Vušković [3], and it plays an essential role in the announced proof of the Strong Perfect Graph Conjecture by Chudnovsky, Robertson, Seymour and Thomas [2]. Then we apply the Reducing Pseudopath Method [13] to characterize the su...

In statistical planning of experiments, super-simple designs are the ones providing samples with maximum intersection as small as possible. Super-simple designs are also useful in other constructions, such as superimposed codes and perfect hash families etc. The existence of super-simple (v, 4, λ)-BIBDs have been determined for λ = 2, 3, 4 and 6. When λ = 5, the necessary conditions of such a d...

A system of Navier–Stokes-type equations with two temperatures is derived, for a polyatomic gas temperature-dependent specific heats (thermally perfect gas), from the ellipsoidal statistical (ES) model Boltzmann equation extended to such gas. Subsequently, applied problem shock-wave structure large bulk viscosity (or, equivalently, slow relaxation internal modes), and numerical results are comp...