Given a graph G = (V,E) with strictly positive integer weights ωi on the vertices i ∈ V , a k-interval coloring of G is a function I that assigns an interval I(i) ⊆ {1, · · · , k} of ωi consecutive integers (called colors) to each vertex i ∈ V . If two adjacent vertices x and y have common colors, i.e. I(i)∩ I(j) 6= ∅ for an edge [i, j] in G, then the edge [i, j] is said conflicting. A k-interv...

This paper models and solves the scheduling problem of cable manufacturing industries that minimizes total production cost, including processing, setup, storing costs. Two hybrid meta-heuristics, which combine simulated annealing variable neighbourhood search algorithms with tabu algorithm, are proposed. Applying some case-based theorems rules, a special initial solution optimal setup cost is o...

This paper presents an innovative approach to support the definition of strategies for the design of alternative configurations of hospital supply chains. This approach was developed around a hybrid Tabu Search / Variable Neighbourhood Search metaheuristic, that uses several neighbourhood structures. The flexibility of the procedure allows its application to supply chains with different topolog...

This study presents a comparison of the performance of four heuristic techniques with oneand two-compartment neighbourhoods in harvest scheduling problems including a spatial objective variable. The tested heuristics were random ascent, Hero, simulated annealing and tabu search. All methods seek better solutions by inspecting the neighbourhood solutions, which are combinations that can be obtai...

This paper presents a hybrid approach that aims at solving the Capacitated Vehicle Routing Problem (CVRP) by means of combining Constraint Programming (CP) with Lagrangian Relaxation (LR) and Probabilistic Algorithms. After introducing the CVRP and reviewing the main literature on this area, the paper proposes the use of a multistart hybrid Variable Neighbourhood Search (VNS) algorithm. This al...

This paper investigates a form of algorithm hybridization that combines constraint satisfaction algorithms with local search algorithms. On one hand, constraint satisfaction algorithms are eeective at nding feasible solutions for tightly constrained problems with complex constraints. On the other hand, local search algorithms are usually better at nding solutions that are good with respect to a...

The workforce scheduling and routing problem (WSRP) is a combinatorial optimisation problem where a set of workers must perform visits to geographically scattered locations. We present a Variable Neighbourhood Search (VNS) metaheuristic algorithm to tackle this problem, incorporating two novel heuristics tailored to the problem-domain. The first heuristic restricts the search space using a prio...

The present work provides a new approach to evolve ligand structures which represent possible drug to be docked to the active site of the target protein. The structure is represented as a tree where each non-empty node represents a functional group. It is assumed that the active site configuration of the target protein is known with position of the essential residues. In this paper the interact...