We define two classes of lower bounds using either one or two simplices for the minimization of a concave function over a polytope. For each of them, a pro...

It is well known that the set of correlated equilibrium distributions of a noncooperative game is a convex polytope that includes all the Nash equilibrium ...

We explore how a simple linear change of variable affects the inclusion functions obtained with Interval Analysis methods. Univariate and multivariate pol...

We develop and analyze parallelization strategies for the Variable Neighborhood Search (VNS) meta-heuristic applied to the <i>p</i>-median problem. The stra...

Albertson (1997) defines the <i>imbalance</i> of an edge (<i>i,j</i>) in <i>E</i> of a graph <i>G</i> = (<i>V,E</i>) as | <i>d_i - d_j</...

Recently, Araujo and De la Pena (1998) gave bounds for the connectivity index of chemical trees as a function of this index for general trees and the ramifi...

We prove that amongst all fullerenes the dodecahedron has maximum smallest eigenvalue (equal to -<img src="G0234-1.gif" align=middle>), followed by the thre...

A survey is made of computer systems which help to obtain and sometimes provide automatically proofs, conjectures and refutations in graph theory.

This paper investigates a new variation in the continuous single facility location problem. Specifically, we address the problem of locating a new facility...

We study various uniform <i>k</i>-partition problems which consist in partitioning <i>m</i> sets, each of cardinality <i>k</i>, into <i>k</i> sets of cardin...

We survey computers systems which help to obtain and sometimes provide automatically conjectures and refutations in algebraic graph theory.

A generalization of the Roy-Gallai theorem on the chromatic number of a graph is derived which is also an extension of several other results of Berge and of...

We give characterizations of integral graphs in the family of complete split graphs and a few related families of graphs.

Variable neighborhood search (VNS) is a recent metaheuristic for solving combinatorial and global optimization problems whose basic idea is systematic chang...

This paper introduces a new kind of operational crew scheduling problem which consists in simultaneously modifying, as necessary, the existing flight depart...

Although airlines plan aircraft routes and crew schedules in advance, perturbations occur everyday. As a result, flight schedules may become infeasible and ...

Proposed just a few years ago, Variable Neighborhood Search (VNS) is a new metaheuristic for combinatorial and global optimization, based upon systematic ch...

This paper solves the problem of designing an access tree network for which the users are connected to the switches through SONET channels on fiber optics l...

This paper describes and solves the operational pilot scheduling problem for one day of operations. The problem consists in simultaneously modifying, as nec...

On the basis of a variable-neighbourhood search with the AutoGraphiX software, it is conjectured that for even numbers of atoms the fully conjugated acycli...