Abstract

Abstract
This paper gives an overview of a trans-european research and development project where a manufacturing team information system was developed. The focus is on the process of requirements analysis and specification, and on the prototype evaluation. Special emphasis is given to the effectiveness of the users involvement in the process. Copyright (C) 2000 IFAC.

Abstract

Abstract
Modelling of laser oscillation at 0.9 mu m in Ti waveguides in LiNbO3 doped with Nd ions is presented. Laser emission at 0.9 mu m in Ti waveguides in Nd:LiNbO3 crystals was recently demonstrated. However, lasing was reported as unstable and lasting only a few seconds, with parasitic lasing at the higher gain transition at 1.08 mu m shown to be a problem. In this work the possibility of obtaining efficient and stable laser oscillation at 0.9 mu m in Ti:LiNbO3 waveguides, fabricated in substrates doped with Nd ions by thermal diffusion of thin metallic stripes or planar thin films, was theoretically evaluated. It was concluded that emission at 0.9 mu m, with complete suppression of the parasitic emission at 1.08 mu m, should be possible by selective increase of the losses at 1.08 Irm, through optimization of waveguide and laser cavity, spatial localization of the Nd ions and the use of the dependence on polarization of the emission cross sections at 0.9 and 1.08 mu m.

Abstract

Abstract
This paper is a formal study of how to implement interaction nets, filling an important gap in the work on this graphical rewriting formalism, very promising for the implementation of languages based on the gimel -calculus. We propose the first abstract machine for interaction net reduction, based on a decomposition of interaction rules into more atomic steps, which tackles all the implementation details hidden in the graphical presentation. As a natural extension of this, we then give a concurrent shared-memory abstract machine, and show how to implement it, resulting in the first parallel implementation of interaction nets.