Massimo Paolucci

Simulated Annealing as an Intensification Component in Hybrid Population-Based Metaheuristics

The use of hybrid metaheuristics applied to combinatorial optimization problems received a continuously increasing attention in the literature. Metaheuristic algorithms differ from most of the classical optimization techniques since they aim at defining effective general purpose methods to explore the solution space, avoiding to tailor them on the specific problem at hand. Often metaheuristics are referred to as “black-box” algorithms as they use limited knowledge about the specific problem to be tackled, instead usually taking inspiration from concepts and behaviours far from the optimization field. This is exactly the case of metaheuristic s like simulated annealing (SA), genetic algorithm (GA), ant colony optimization (ACO) or particle swarm optimization (PSO). Metaheuristics are based on a subset of features (e.g., the use of exploration history as short or long term memory, that of learning mechanisms or of candidate solution generation techniques) that represent a general algorithm fingerprint which usually can be easily adapted to face different complex real world problems. The effectiveness of any metaheuristic applied to a specific combinatorial problem may depend on a number of factors: most of the time no single dominating algorithm can be identified but several distinct mechanisms exploited by different metaheuristics appear to be profitable for searching high quality solutions. For this reason a growing number of metaheuristic approaches to combinatorial problems try to put together several techniques and concepts from different methods in order to design new and highly effective algorithms. Hybrid approaches in fact usually seem both to combine complementary strengths and to overcome the drawbacks of single methods by embedding in them one or more steps based on different techniques. As an example, in (Anghinolfi & Paolucci, 2007a) the SA probabilistic candidate solution acceptance rule is coupled with the tabu list and neighbourhood change mechanisms respectively characterizing tabu search (TS) and variable neighbourhood search (VNS) approaches to face parallel machine total tardiness scheduling problems. Several surveys exist proposing both classifications of metaheuristics and unified views of hybr id metaheuristic s (e.g., (Blum & Roli, 2003), (Doerner et al., 2007), (Raidl, 2006) and (Talbi, 2002)). We would avoid to replicate here the various definitions and classifications through which the different approaches can be analysed and organized (the interested reader can for example refer to (Blum & Roli, 2003) Open Access Database www.i-techonline.com

The MAKE-IT project: Manufacturing Agents in a Knowledge-based Environment driven by Internet Technologies

MAKE-IT (Manufacturing Agents in a Knowledge-based Environment driven by Internet Technologies) is a research project whose objective is the definition and the implementation of small software architectures that can be taken into account as agents - which can perform simple rule-based actions while performing a quite heavy and complex coordination. The main field of application of the MAKE-IT agents is the workflow management of information in small or medium-sized manufacturing enterprises, specifically when their information system is based on the Microsoft Windows architecture.

A Distributed Service-Based Software Infrastructure for Trip Planning in Motorway Auto-routes Context

This paper presents TRIPLAN, a distributed service-based software architecture providing the European travellers, who are planning their journeys, with high quality information in order to make them taking decisions about trip planning, by taking into account both predicted traffic conditions and real time ones. The TRIPLAN architecture is solution based on the following criteria: use state-of-the-art and innovative methodologies and techniques; exploiting the available information for providing more effective advices; enforcing standards for information exchange and cooperation among different systems in TERN; assessment and continuous upgrade of a knowledge base on traffic conditions; provide a set of architectural guidelines for a service information network. The focus of the work presented in this paper is the design of the SW architecture for providing via Web a traffic planning service based on an integrated informative system.