Abstract
This paper introduces a new upper bound to the problem of fitting identical circles into a rectangle. This problem is usually referred to as the ‘cylinder packing problem’ or ‘cylinder palletization’. In practice, it arises when it is desired to maximize the number of cylindrical items packed in an upright position onto a rectangle/pallet. The upper bound developed consists in determining the reduced pallet area by deducting a lower bound for the unused pallet area from the total area of the pallet. The upper bound for the number of identical circles to pack into the pallet is computed by the ratio reduced pallet area/circle area. The results obtained for five distinct sets of problems are analyzed and compared with previous bounds found in the published literature. International Federation of Operational Research Societies 2001.

Abstract
This paper presents the requirements for an information system supporting the cooperation in networks of enterprises. First, these networks are characterised, focusing on the variable coupling of the participating enterprises and on the consequent needs of co-operation. Departing from those needs, the concept of an information system based on an architecture of agents is presented. A generic infrastructure to implement the system is outlined, including the main interaction scenarios. The next steps of this research work end the paper.

Abstract
This paper presents a conceptual framework where the development of an information system for aggregate management of virtual / networked enterprises is taking place. Firstly, the general objectives of the system are described. An ontology based development approach is presented, assuming the role of conceptual guidance, both for the requirements analysis and design phases. Finally, a broad specification of aggregate management in this context is described through use cases.

Abstract
Due to their efficiency and their interesting design and implementation features, metaheuristics have been used for a long time with success, in dealing with combinatorial problems. In recent years they have been applied to the Unit Commitment problem with rather interesting results that justify further research in the area. In this paper we present a Simulated Annealing approach to the Unit Commitment problem. Two coding schemes are compared, new neighbourhood structures are presented and some searching strategies are discussed. Preliminary computational experience, performed on some test instances, shows that this approach is flexible, effective and able to handle variations on the problem structure. © 2001 IEEE.

Abstract
This paper describes the methods and experiences of developing of an information system in an industrial innovation context. The case analysed respects to a system supporting quality management tasks of working teams in industrial companies, developed within a research & development EU funded project. The initial concept of the system is described first, followed by the way how requirements where elicited and structured and the system specified. Next, design and prototyping are analysed , detailing the end-users evaluation approach. Conclusions are drawn on the opportunities and difficulties od R&D involving industrial enterprises.

Abstract
This paper presents a conceptual foundation for enterprise modelling from the social and organisational viewpoints. First, a method for the qualitative evaluation of enterprise modelling methods according to those viewpoints is presented. Next, the proposed approach of methodological mediation through a social and organisational conceptual core is outlined, and its implementation using the so called ontological engineering explained. Copyright (C) 2000 IFAC.