Abstract
Differential group delay (DGD) generation by inducing birefringence in uniform fiber Bragg gratings (FBG) is studied. Applying a transverse load, a birefringence is induced on a uniform FBG creating a tunable differential group delay. A theoretical behavior of this phenomenon is presented being in good agreement with the experimental results obtained. A maximum experimental tunable DGD of similar to 60 ps was obtained with this induced birefringent process in the uniform FBG. (C) 2007 Wiley Periodicals. Inc.

Abstract
This paper presents an artificial neural network approach for short-term electricity prices forecasting. In the new deregulated framework, producers and consumers require short-term price forecasting to derive their bidding strategies to the electricity market. Accurate forecasting tools are required for producers to maximize their profits and for consumers to maximize their utilities. A three-layered feedforward artificial neural network, trained by the Levenberg-Marquardt algorithm, is used for forecasting the next 168 hour electricity prices. We evaluate the accuracy of the price forecasting attained with the proposed approach, reporting the numerical results from a real-world case study based on an electricity market.

Abstract

Abstract
We present a new group of audio effects that use beat tracking, the detection of beats in an audio signal, to relate effect parameters to the beats in an input signal. Conventional audio effects are augmented so that their operation is related to the output of a beat tracking system. We present a temposynchronous delay effect and a set of beat synchronous low frequency oscillator effects including tremolo, vibrato and auto-wah. All effects are implemented in real-time as VST plug-ins to allow for their use in live performance.

Abstract
A linear tunable dispersion compensation device based on a chirped grating (CFBG) mounted on a stretching mechanical structure is described. The tunability is obtained changing the CFBG bandwidth without modification of the total length structure. (c) 2007 Wiley Periodicals, Inc.

Abstract
Originally defined by the Third Generation Partnership Project (3GPP) as part of its standardization work for 3G mobile phone systems, the IMS model has been adopted as a baseline technology for network and service convergence by network (wireless, wireline and cable), service and content operators. Dealing with the same business actors, the ENTHRONE project (FP6-IP-507637) builds an MPEG-21-based service management system that enables distribution of audio-visual content with dynamic end-to-end QoS guarantees over heterogeneous networks to various types of terminal devices. This system controls the access of users to the content and supervises the delivery of the content to ensure the level of QoS. The paper examines how the IMS model could be extended to include service management features offered by the ENTHRONE management system. These features could constitute a potential vehicle for the IMS entrance to the audio-visual market chain. Copyright © 2007 John Wiley & Sons, Ltd.