Maria Antónia Carravilla

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Keywords: Metaheuristics VNS Glass container industry Production planning and scheduling Color changeover a b s t r a c t Inspired by a case study, this paper reports a successful application of VNS to the production planning and scheduling problem that arises in the glass container industry. This is a multi-facility production system, where each facility(More)
In this paper an application of constraint logic programming (CLP) to the resolution of nesting problems is presented. Nesting problems are a special case of the cutting and packing problems, in which the pieces generally have non-convex shapes. Due to their combinatorial optimization nature, nesting problems have traditionally been tackled by heuristics(More)
Nesting problems are combinatorial optimisation problems where one or more pieces of material or space must be divided into smaller irregular pieces, minimising the waste. In OR, the state-of-the-art in nesting problems is to solve them by means of heuristic algorithms; the use of mixed integer programming models can handle only rather small instances. The(More)
— The aim of this paper is to present and compare alternative hierarchical formulations for the periodic vehicle routing problem applied to solid waste collection. The solution of this problem is a one-week plan of daily routes for the transportation of mixed solid waste from containers to disposal facilities, taking into consideration the frequency of(More)
In the 2005 Portuguese Parliament General Elections there were non-valid experiments of e-voting at five voting places and also through the Internet. Faculdade de Engenharia da Universidade do Porto audited such experiments. Relevant security, transparency, usability and accessibility evaluation criteria and sub-criteria were defined, and an auditing(More)