Contingency situations may cause emergency states in distribution systems; these states are defined as the interruption of power supply. Such situations should be avoided whenever possible in order to maintain certain quality limits related to frequency and duration of interruptions. The main...

We propose the use of metaheuristics for the resource-capacitated multilevel lot-sizing problem with general product structures, setup costs, setup times, and lead times. Initially, we develop a heuristic which moves production in time in order to obtain feasible solutions with good quality....

We consider the two-level network design problem with intermediate facilities. This problem consists of designing a minimum cost network respecting some requirements, usually described in terms of the network topology or in terms of a desired flow of commodities between source and destination...

The lot-sizing problem considered in this paper consists in planning the production of multiple items on a single machine over a finite planning horizon divided into time periods. The objective of the problem is to determine a minimum cost production plan that meets the forecast demand for the...

Emergency medical services (EMS) assist different classes of patients according to their medical seriousness. In this study, we extended the well-known hypercube model, based on the theory of spatially distributed queues, to analyze systems with multiple priority classes and a queue for waiting...

In this paper we propose a cutoff hypercube queuing model to analyze server-to-customer emergency services operating with server reservation. We are motivated by certain SAMU’s (Système d’Aide Médicale Urgente) that give assistance to different classes of emergency requests, including...

In this study we deal with network routing decisions and approximate performance evaluation approaches for generalized open queuing networks (OQN), in which commodities enter the network, receive service at one or more arcs and then leave the network. Exact performance evaluation has been...

This study presents an optimization approach by mathematical modelling to support some of the main operational decisions in steam production systems with multiple industrial boilers. Decisions are related to boiler operations scheduling (start-up, warm-up and shutdown time), fuel replenishment...

In this study we deal with the two-dimensional non-guillotine cutting problem of how to cut a set of larger rectangular objects to a set of smaller rectangular items in exactly a demanded number of pieces. We are concerned with the special case of the problem in which the non-used material of...