Abstract
We have flattened the gain spectrum of a commercial Erbium-doped fibre amplifier, obtaining a curve with approximately 3 dB of ripple, from 1524 nm to 1551 nm, using long-period fibre gratings as equalising optical filters. The fabrication principle of the long-period fibre grating is based on the electric arc technique.

Abstract

Abstract
Field communication systems (fieldbuses) are widely used as the communication support for distributed computer-controlled systems (DCCS) within all sort of process control and manufacturing applications. There are several advantages in the use of fieldbuses as a replacement for the traditional point-to-point links between sensors/actuators and computer-based control systems, within which the most relevant is the decentralisation and distribution of the processing power over the field. A widely used fieldbus is the WorldFIP, which is normalised as European standard EN 50170. Using WorldFIP to support DCCS, an important issue is "how to guarantee the timing requirements of the real-time traffic?" WorldFIP has very interesting mechanisms to schedule data transfers, since it explicitly distinguishes periodic and aperiodic traffic. In this paper, we describe how WorldFIP handles these two types of traffic, and more importantly, we provide a comprehensive analysis on how to guarantee the timing requirements of the real-time traffic. (C) 2001 Published by Elsevier Science B.V.

Abstract
The aim of behavioural cloning is to synthesize artificial controllers that are robust and comprehensible to human understanding. To attain the two objectives we propose the use of the Incremental Correction model that is based on a closed-loop control strategy to model the reactive aspects of human control skills. We have investigated the use of three different representations to encode the artificial controllers: univariate decision trees as induced by C4.5; multivariate decision and regression trees as induced by cart and; clausal theories induced by an Inductive Logic Programming (ILP) system. We obtained an increase in robustness and a lower complexity of the controllers when compared with results using other models. The controllers synthesized by cart revealed to be the most robust. The ILP system produced the simpler encodings. © Springer-Verlag Berlin Heidelberg 2001.

Abstract
A twin polarimetric configuration based on the Faraday effect for the measurement of electric currents in high voltage environments is presented. Field test results are shown that indicate the device suitability for current metering and relaying applications. © 2001 IEEE.

Abstract
We report, for the first time to our knowledge, the excellent optical performance of long-period gratings written in three standard libers and in two nonstandard fibers, namely, S-doped and N-doped fibers, using the flexible and low-cost electric are technique. The fundamental mechanism for their formation is proposed. The gratings thermal behavior and the effect of fiber preannealing prior to writing have been investigated. We have demonstrated a good stability of these gratings at high temperatures.